Hystricognathy vs Sciurognathy in the Rodent Jaw: A New Morphometric Assessment of Hystricognathy Applied to the Living Fossil Laonastes (Diatomyidae)

PubMed Central

Hautier, Lionel; Lebrun, Renaud; Saksiri, Soonchan; Michaux, Jacques; Vianey-Liaud, Monique; Marivaux, Laurent

2011-01-01

While exceptional for an intense diversification of lineages, the evolutionary history of the order Rodentia comprises only a limited number of morphological morphotypes for the mandible. This situation could partly explain the intense debates about the taxonomic position of the latest described member of this clade, the Laotian rock rat Laonastes aenigmamus (Diatomyidae). This discovery has re-launched the debate on the definition of the Hystricognathi suborder identified using the angle of the jaw relative to the plane of the incisors. Our study aims to end this ambiguity. For clarity, it became necessary to revisit the entire morphological diversity of the mandible in extant and extinct rodents. However, current and past rodent diversity brings out the limitations of the qualitative descriptive approach and highlights the need for a quantitative approach. Here, we present the first descriptive comparison of the masticatory apparatus within the Ctenohystrica clade, in combining classic comparative anatomy with morphometrical methods. First, we quantified the shape of the mandible in rodents using 3D landmarks. Then, the analysis of osteological features was compared to myological features in order to understand the biomechanical origin of this morphological diversity. Among the morphological variation observed, the mandible of Laonastes aenigmamus displays an intermediate association of features that could be considered neither as sciurognathous nor as hystricognathous. PMID:21490933

Comparison between cone-beam and multislice computed tomography depicting mandibular neurovascular canal structures.

PubMed

Naitoh, Munetaka; Nakahara, Kino; Suenaga, Yutaka; Gotoh, Kenichi; Kondo, Shintaro; Ariji, Eiichiro

2010-01-01

The most common diagnostic imaging modalities for cross-sectional imaging in dental implant planning are currently cone-beam computed tomography (CBCT) and multislice CT (MSCT). However, clinical differences between CBCT and MSCT in this task have not been fully clarified. In this investigation, the detection of fine anatomical structures in the mandible was assessed and compared between CBCT and MSCT images. The sample consisted of 28 patients who had undergone CBCT and MSCT. The bifid mandibular canal in the mandibular ramus, accessory mental and buccal foramina, and median and lateral lingual bony canals were observed in 2-D images, and the findings were compared between CBCT and MSCT. Four of 19 canals observed in CBCT were not observed in MSCT images. Three accessory mental foramina in 2 patients and 28 lateral lingual bony canals in 18 patients were observed consistently using the two methods. Depiction of fine anatomic features in the mandible associated with neurovascular structures is consistent between CBCT and MSCT images. Copyright 2010 Mosby, Inc. All rights reserved.

Rare case of unifocal Langerhans cell histiocytosis in four-month-old child.

PubMed

Martins, Marco Antonio T; Gheno, José Luis N; Sant'Ana Filho, Manoel; Pinto, Décio S; Tenis, Carlos Alberto; Martins, Manoela D

2011-07-01

Langerhans cell histiocytosis (LCH) comprises a group of disorders, the common feature of which is Langerhans cell proliferation. The clinical presentation is highly varied. The severity and prognosis of the disease are dependent on the type and extent of organ involvement. This paper reports a rare case of a four-month-old white male with unifocal LCH limited exclusively to the mandible, discussing the diagnosis, radiographic and immunohistochemical aspects, treatment and monitoring multidisciplinary of the case. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Cemento-ossifying fibroma.

PubMed

Ram, Rangila; Singhal, Anita; Singhal, Parul

2012-01-01

The cemento-ossifying fibroma is classified as a fibro-osseous lesion of the jaws. It commonly presents as a progressively growing lesion that can attain an enormous size with resultant deformity if left untreated. A case of cemento-ossifying fibroma involving the left mandible is described in a 35 year old female patient. The clinical, radiographic and histological features as well as surgical findings are presented. The cemento-ossifying fibroma is a central neoplasm of bone as well as the periodontium which has caused considerable controversy because of the confusion regarding terminology and the criteria for its diagnosis.

Cemento-ossifying fibroma

PubMed Central

Ram, Rangila; Singhal, Anita; Singhal, Parul

2012-01-01

The cemento-ossifying fibroma is classified as a fibro-osseous lesion of the jaws. It commonly presents as a progressively growing lesion that can attain an enormous size with resultant deformity if left untreated. A case of cemento-ossifying fibroma involving the left mandible is described in a 35 year old female patient. The clinical, radiographic and histological features as well as surgical findings are presented. The cemento-ossifying fibroma is a central neoplasm of bone as well as the periodontium which has caused considerable controversy because of the confusion regarding terminology and the criteria for its diagnosis. PMID:22557904

Onset of mandible and tibia osteoradionecrosis – a comparative pilot study in the rat

PubMed Central

Damek-Poprawa, Monika; Both, Stefan; Wright, Alexander C.; Maity, Amit; Akintoye, Sunday O.

2012-01-01

Objectives Osteoradionecrosis (ORN) is common in the jaws following radiotherapy. We hypothesized that mandible is more susceptible to ORN than tibia based on site-disparity in hypoxic-hypocellular-hypovascular tissue breakdown. Study Design Twelve rats received 50 Gy irradiation to mandible or tibia; 4 of 12 rats further received minor surgical trauma to the irradiated sites. Structural and cellular skeletal changes were assessed with computer tomography, histology and immunostaining. Results Mandible developed ORN with 70% mean bone loss 10 weeks post-irradiation (p < 0.05) while tibia was structurally and radiological intact for 20 weeks post-irradiation. Hypocellularity, hypoxia and oxidative stress were higher in irradiated mandible (p < 0.001) than tibia (p < 0.01) but vascular damage was similar at both skeletal sites. Combined effects of radiation and minor trauma promoted mandibular alveolar bone loss and tibial fracture Conclusion ORN has a more rapid onset in mandible relative to tibia in the rat PMID:23254371

The Additively Manufactured Porous NiTi and Ti-6Al-4V in Mandibular Reconstruction: Introducing the Stiffness-Matched and the Variable Stiffness Options for the Reconstruction Plates

NASA Astrophysics Data System (ADS)

Jahadakbar, Ahmadreza

Mandibular reconstruction surgery is a part of treatment for cancer, tumor, and all the cases that involve segmental defects. One of the most common approaches for the reconstruction surgery is to resect the segmental defect and use a double barrel fibula graft to fill the resected region and recover the mandible's normal functions, such as chewing. The grafted bone is connected to the host mandible, using the standard of the care Ti-6Al-4V fixation plates. The fixation plates are available in the form of prefabricated plates and also patient-specific plates in the market. Due to the high stiffness of the Ti-6Al-4V plates in comparison with the mandible bone and the grafted bone, the loading distribution on the whole reconstructed mandible will be different from a healthy mandible. The high stiffness fixation hardware carries a great portion of the loading and causes stress shielding on the grafted bone and the surrounding host bone. Based on the bone remodeling theory, the stress shielding on the cortical bone causes bone resorption and may lead to implant failure. A solution to reduce the risk of implant failure is to use a low stiffness biocompatible material for the mandibular fixation plates. We have proposed the use of stiffness-matched, porous NiTi fixation plates either in the form of patient-specific or prefabricated, instead of the standard of the care Ti-6Al-4V plates. NiTi is a biocompatible material that has a low stiffness in comparison with Ti-6Al-4V and also benefits from the superelastic feature. Superelasticity, which can also be found in bone tissues, allows the material to recover large strains (up to 8%) and increases the shock absorption. In this thesis, we have evaluated the use of proposed fixation hardware by comparing it with a healthy mandible and a reconstructed mandible using the standard method. To this end, first different models including a healthy mandible, a reconstructed mandible using patient-specific Ti-6Al-4V fixation hardware, a reconstructed mandible using stiffness-match patient-specific hardware, and several prefabricated fixation plates were prepared. After verification of the models, the cases of reconstructed mandibles were used to simulate different periods, including during healing, and post-healing periods. Also, different loading conditions including highest bite force on the first molar tooth, rest condition, and also highest bite force on a dental implant right in the grafted bone were simulated. Also, the theory of applying pretention to the fixation plates was evaluated using the finite element method. We also designed and evaluated a set of prefabricated fixation kits with various stiffness option. After all these finite element simulations and having the CAD files of the porous fixation plates, the possibility of fabrication of the proposed hardware, in both forms of patient-specific, and prefabricated plates was evaluated using selective laser melting.

Cemento-Osseous Dysplasias: Imaging Features Based on Cone Beam Computed Tomography Scans.

PubMed

Cavalcanti, Paulo Henrique Pereira; Nascimento, Eduarda Helena Leandro; Pontual, Maria Luiza Dos Anjos; Pontual, Andréa Dos Anjos; Marcelos, Priscylla Gonçalves Correia Leite de; Perez, Danyel Elias da Cruz; Ramos-Perez, Flávia Maria de Moraes

2018-01-01

Imaging exams have important role in diagnosis of cemento-osseous dysplasia (COD). Cone beam computed tomography (CBCT) stands out for allowing three-dimensional image evaluation. This study aimed to assess the prevalence of cases diagnosed as COD on CBCT scans, as well identify the main imaging features related to these lesions. An analysis was performed in a database containing 22,400 radiological reports, in which all cases showing some type of COD were initially selected. These CBCT exams were reevaluated to confirm the radiographic diagnosis and determine the prevalence and distribution of the types of COD with regard to gender, age and preferred location, while describing its most common imaging aspects. Data were presented using descriptive analyses. There were 82 cases diagnosed as COD in the CBCT images (prevalence of 0.4%). The distribution of patients was 11 (13.4%) male and 71 (86.6%) female, with a mean age of 49.8 years (age-range 17-85 years). There were 47 (57.3%) cases of periapical COD, 23 (28%) of focal COD and 12 (14.6%) of florid COD. The mandible was more affected than the maxilla. In most cases, the lesions were mixed or hyperdense. All COD had well-defined limits and there were no cases of tooth displacement. In conclusion, periapical COD was the most common type and the most affected bone was the mandible. Imaging evaluation is critical for diagnosis and dentists should bear in mind all possible radiographic presentations of COD in order to prevent misleading diagnoses and consequently, inadequate treatments.

Automatic segmentation of mandible in panoramic x-ray.

PubMed

Abdi, Amir Hossein; Kasaei, Shohreh; Mehdizadeh, Mojdeh

2015-10-01

As the panoramic x-ray is the most common extraoral radiography in dentistry, segmentation of its anatomical structures facilitates diagnosis and registration of dental records. This study presents a fast and accurate method for automatic segmentation of mandible in panoramic x-rays. In the proposed four-step algorithm, a superior border is extracted through horizontal integral projections. A modified Canny edge detector accompanied by morphological operators extracts the inferior border of the mandible body. The exterior borders of ramuses are extracted through a contour tracing method based on the average model of mandible. The best-matched template is fetched from the atlas of mandibles to complete the contour of left and right processes. The algorithm was tested on a set of 95 panoramic x-rays. Evaluating the results against manual segmentations of three expert dentists showed that the method is robust. It achieved an average performance of [Formula: see text] in Dice similarity, specificity, and sensitivity.

Peripheral osteoma, compound odontoma, focal cemento-osseous dysplasia, and cemento-ossifying fibroma in the same hemimandible: CBCT findings of an unusual case.

PubMed

Borghesi, Andrea; Tonni, Ingrid; Pezzotti, Stefania; Maroldi, Roberto

2017-12-01

Peripheral osteoma is the most common subtype of osteoma that arises most frequently in the craniofacial bones. It may occur at any age with a male-to-female ratio of 2:1. Peripheral osteoma may affect the mandible, particularly the ramus and the condyle. Compound odontoma is a subtype of odontoma that occurs in young subjects without gender predilection. It affects the maxilla more frequently than the mandible. Focal cemento-osseous dysplasia and cemento-ossifying fibroma are 2 benign fibro-osseous lesions with a female predominance that occur most commonly in the posterior region of the mandible. We report the first case involving the simultaneous occurrence of these 4 benign lesions in the same hemimandible diagnosed by CBCT.

Comparative gene expression supports the origin of the incisor and molar process from a single endite in the mandible of the red flour beetle Tribolium castaneum

PubMed Central

2013-01-01

Background The biting edge of the primitive arthropod mandible consists of a biting incisor process and a crushing molar process. These structures are thought to be derived from a structure known as an endite but the precise details of this are not understood. Various hypotheses concerning the number of endites present in the arthropod mandible have been proposed. In the developing embryo, the mandible has an inner and outer lobe that are likely to develop into the incisor and molar processes of the larval mandible; these two lobes are commonly held to be derived from separate endites and to be serially homologous to the galea and lacinia endites of the maxillary appendage respectively (Machida). Results We undertook a study of the development of the embryonic mandible of the beetle Tribolium castaneum using the expression of developmental genes as markers of the developing endites in the mandible and maxilla. The Tribolium ortholog of paired (Tc-prd) has expression domains in the developing maxillary and labial endites as well as the inner and outer lobes of the mandible. Following the expression of Tc-prd in the developing mandible through to late stage embryos shows that the molar and incisor process develop from the inner and outer lobes respectively. In addition to Tc-prd, we compared the expression of genes in the endites of the maxilla to the mandible to draw conclusions about the number of endites in the mandible. Homologs of dachshund are typically expressed in the endites of mandibulate gnathal appendages. Comparison of the expression of Tc-prd, Tribolium dachshund (Tc-dac) and Tribolium wingless (Tc-wg) between the endites of the maxilla and the mandible suggest that, while there are two endites in the maxilla only a single endite is present in the mandible. Conclusions Comparative gene expression suggests that the Tribolium mandible has a single endite from which both mandible lobes are derived. Our results do not support Machida’s hypothesis homologising the incisor and molar processes of the mandible to the galea and lacinia endites of the maxilla. We propose, instead, that both incisor and molar processes are derived from a single endite serially homologous to the lacinia of the maxilla. PMID:23280103

On the Variability of the Dmanisi Mandibles

PubMed Central

Bermúdez de Castro, José María; Martinón-Torres, María; Sier, Mark Jan; Martín-Francés, Laura

2014-01-01

The description of a new skull (D4500) from the Dmanisi site (Republic of Georgia) has reopened the debate about the morphological variability within the genus Homo. The new skull fits with a mandible (D2600) often referred as ‘big’ or ‘enigmatic’ because of its differences with the other Dmanisi mandibles (D211 and D2735). In this report we present a comparative study of the variability of the Dmanisi mandibles under a different perspective, as we focus in morphological aspects related to growth and development. We have followed the notion of modularity and phenotypic integration in order to understand the architectural differences observed within the sample. Our study reveals remarkable shape differences between D2600 and the other two mandibles, that are established early in the ontogeny (during childhood or even before) and that do not depend on size or sexual dimorphism. In addition, D2600 exhibits a mosaic of primitive and derived features regarding the Homo clade, which is absent in D211 and D2735. This mosaic expression is related to the location of the features and can be explained under the concept of modularity. Our study would support the possibility of two different paleodemes represented at the Dmanisi site. This hypothesis has been previously rejected on the basis that all the individuals were constrained in the same stratigraphic and taphonomic settings. However, our revision of the complex Dmanisi stratigraphy suggests that the accumulation could cover an undetermined period of time. Even if “short” in geological terms, the hominin accumulation was not necessarily synchronic. In the same line we discard that the differences between D2600 and the small mandibles are consequence of wear-related dentoalveolar remodeling. In addition, dental wear pattern of D2600 could suggest an adaptation to a different ecological niche than the other Dmanisi individuals. PMID:24586309

Anatomical shape analysis of the mandible in Caucasian and Chinese for the production of preformed mandible reconstruction plates.

PubMed

Metzger, Marc C; Vogel, Mathias; Hohlweg-Majert, Bettina; Mast, Hansjörg; Fan, Xianqun; Rüdell, Alexandra; Schlager, Stefan

2011-09-01

The purpose of this study was to evaluate and analyze statistical shapes of the outer mandible contour of Caucasian and Chinese people, offering data for the production of preformed mandible reconstruction plates. A CT-database of 925 Caucasians (male: n=463, female: n=462) and 960 Chinese (male: n=469, female: n=491) including scans of unaffected mandibles were used and imported into the 3D modeling software Voxim (IVS-Solutions, Chemnitz, Germany). Anatomical landmarks (n=22 points for both sides) were set using the 3D view along the outer contour of the mandible at the area where reconstruction plates are commonly located. We used morphometric methods for statistical shape analysis. We found statistical relevant differences between populations including a distinct discrimination given by the landmarks at the mandible. After generating a metric model this shape information which separated the populations appeared to be of no clinical relevance. The metric size information given by ramus length however provided a profound base for the production of standard reconstruction plates. Clustering by ramus length into three sizes and calculating means of these size-clusters seem to be a good solution for constructing preformed reconstruction plates that will fit a vast majority. Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

An Early Pleistocene hominin mandible from Atapuerca-TD6, Spain

PubMed Central

Carbonell, E.; Bermúdez de Castro, J. M.; Arsuaga, J. L.; Allue, E.; Bastir, M.; Benito, A.; Cáceres, I.; Canals, T.; Díez, J. C.; van der Made, J.; Mosquera, M.; Ollé, A.; Pérez-González, A.; Rodríguez, J.; Rodríguez, X. P.; Rosas, A.; Rosell, J.; Sala, R.; Vallverdú, J.; Vergés, J. M.

2005-01-01

We present a mandible recovered in 2003 from the Aurora Stratum of the TD6 level of the Gran Dolina site (Sierra de Atapuerca, northern Spain). The specimen, catalogued as ATD6-96, adds to the hominin sample recovered from this site in 1994–1996, and assigned to Homo antecessor. ATD6-96 is the left half of a gracile mandible belonging to a probably female adult individual with premolars and molars in place. This mandible shows a primitive structural pattern shared with all African and Asian Homo species. However, it is small and exhibits a remarkable gracility, a trait shared only with the Early and Middle Pleistocene Chinese hominins. Furthermore, none of the mandibular features considered apomorphic in the European Middle and Early Upper Pleistocene hominin lineage are present in ATD6-96. This evidence reinforces the taxonomic identity of H. antecessor and is consistent with the hypothesis of a close relationship between this species and Homo sapiens. PMID:15824320

Primary Intraosseous Adenoid Cystic Carcinoma of the Mandible: A Comprehensive Review With Analysis of 2 Additional Cases.

PubMed

Hu, Hong Ying; Liu, Yuan Yuan; Wang, Hu; Jiang, Meng

2017-08-01

Primary intraosseous adenoid cystic carcinoma (IACC) of the mandible is poorly understood because of its rarity. This study performed a comprehensive literature review on IACC of the mandible. Forty-five cases of IACC reported in the literature and 2 additional cases in the authors' hospital were reviewed. IACC of the mandible generally occurred in the fourth to sixth decades, with no meaningful gender predilection. Pain and swelling were the most common clinical manifestations. Radical surgery combined with postsurgical radiotherapy was recommended as the best treatment. The diagnosis of IACC should be based on clinical, radiologic, and pathologic examinations. Radical surgery combined with postsurgical radiotherapy seems to be the best treatment. In addition, the histologic subtype of the tumor is an important prognostic factor in patients with IACC. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Adaptation of the muscles of mastication to the flat skull feature in the polar bear (Ursus maritimus).

PubMed

Sasaki, M; Endo, H; Yamagiwa, D; Takagi, H; Arishima, K; Makita, T; Hayashi, Y

2000-01-01

The muscles of mastication of the polar bear (Ursus maritimus) and those of the brown bear (U. arctos) were examined by anatomical approach. In addition, the examination of the skull was carried out in the polar bear, brown bear and giant panda (Ailuropoda melanoleuca). In the polar bear, the rostro-ventral part of the superficial layer of the M. masseter possessed the abundant fleshy portion folded in the rostral and lateral directions like an accordion. Moreover, the rostro-medial area of the superficial layer became hollow in the nuchal direction when the mouth was closed. The M. temporalis of the polar bear covered up the anterior border of the coronoid process of the mandible and occupied the almost entire area of the cranial surface. The M. pterygoideus medialis of the polar bear was inserted on the ventral border of the mandible and on the ventral part of the temporal bone more widely than that of the brown bear. As results of our measurements of the mandible, an effect of the leverage in the polar bear was the smallest in three species. In the polar bear, the skull was flat, and the space between zygomatic arch and ventral border of the mandible, occupied by the M. masseter was the narrowest. It is suggested that the muscles of mastication of the polar bear is adapted to the flat skull feature for supplementing the functions.

Cemento-ossifying fibroma of mandible: An unusual case report and review of literature.

PubMed

Mohapatra, Mounabati; Banushree, C S; Nagarajan, K; Pati, Debashish

2015-01-01

The term ossifying fibroma (OF) has recently been included under fibro-osseous lesions. Cemento-OF (COF) is a benign neoplasm that arises from the periodontal membrane which contains multipotential cells that are capable of forming cementum, lamellar bone and fibrous tissue. These tumors occur in the third and fourth decades of life with a predilection for women. The mandible is more commonly involved than the maxilla. This lesion has caused considerable controversy regarding the use of terminology, origin and diagnostic criteria. This article describes an unusual case of COF presenting as unilocular lytic lesion of mandible in a 38-year-old male patient with review of literature.

Cemento-ossifying fibroma of mandible: An unusual case report and review of literature

PubMed Central

Mohapatra, Mounabati; Banushree, CS; Nagarajan, K; Pati, Debashish

2015-01-01

The term ossifying fibroma (OF) has recently been included under fibro-osseous lesions. Cemento-OF (COF) is a benign neoplasm that arises from the periodontal membrane which contains multipotential cells that are capable of forming cementum, lamellar bone and fibrous tissue. These tumors occur in the third and fourth decades of life with a predilection for women. The mandible is more commonly involved than the maxilla. This lesion has caused considerable controversy regarding the use of terminology, origin and diagnostic criteria. This article describes an unusual case of COF presenting as unilocular lytic lesion of mandible in a 38-year-old male patient with review of literature. PMID:26980975

Pediatric maxillofacial fractures.

PubMed

Spring, P M; Cote, D N

1996-05-01

Maxillofacial trauma in the pediatric population is a relatively infrequent occurrence. Studies have demonstrated consistently that 5% of all facial fractures occur in children. The low percentage of facial fractures in this age group has been attributed, in part, to the lack of full pneumatization of the sinuses until later in childhood. Review of the literature indicates that boys are more commonly affected than girls and that the majority of pediatric facial fractures occur in children between 6 and 12 years of age. Motor vehicle accidents, falls, and blunt trauma are responsible for the largest number of pediatric facial fractures. The most common site of facial fracture is the nose and dentoalveolan complex, followed by the mandible, orbit, and midface in most pediatric cohorts. Management of the mandible is often conservative owing to the high percentage of isolated condylar fractures in children. Open reduction and internal fixation of pediatric facial fractures is indicated in complex mandible, midface, and orbital fractures. The effect of rigid fixation on facial skeleton growth is not completely understood.

Dental esthetics--instrument for recreating a new facial esthetic to the elderly patient.

PubMed

Scutariu, Mihaela Monica; Forna, Norina

2014-01-01

The major objective of this paper consists in underlining the wide range of possibilities in assessing the elderly patient; it relies on clinical examination in order to exclusively improve the patient's physiognomic aspect. In this context it has been organized a study which included 64 elderly patients aged between 60 and 90 years of age (median age 75), which presented themselves at the Clinical Service of Dental Semiology and Gerontostomatology between 2011-2012; they requested the restoration of the functions affected by odontal coronary lesions, periodontal disorders or edentations more or less expanded, malocclusions, malrelations of the mandible to the skull and unsuccessful or deteriorated dental or prosthetic treatments. The restoration of dental arches has been performed relying on common sense and power of discernment, respecting both facial features and expression by redimensioning the lower part of the face, repositioning the mandible and using gnatoprosthetic devices. Solving the problems elderly patients confront themselves with and the success of the treatment has been possible only after a correct assessment of the involutive phenomena that influence the oral cavity, after understanding the local and general factors that predispose to oral disorders as well as the differences between various techniques and materials.

The Comprehensive AOCMF Classification System: Mandible Fractures-Level 3 Tutorial

PubMed Central

Cornelius, Carl-Peter; Audigé, Laurent; Kunz, Christoph; Rudderman, Randal; Buitrago-Téllez, Carlos H.; Frodel, John; Prein, Joachim

2014-01-01

This tutorial outlines the details of the AOCMF image-based classification system for fractures of the mandibular arch (i.e. the non-condylar mandible) at the precision level 3. It is the logical expansion of the fracture allocation to topographic mandibular sites outlined in level 2, and is based on three-dimensional (3D) imaging techniques/computed tomography (CT)/cone beam CT). Level 3 allows an anatomical description of the individual conditions of the mandibular arch such as the preinjury dental state and the degree of alveolar atrophy. Trauma sequelae are then addressed: (1) tooth injuries and periodontal trauma, (2) fracture involvement of the alveolar process, (3) the degree of fracture fragmentation in three categories (none, minor, and major), and (4) the presence of bone loss. The grading of fragmentation needs a 3D evaluation of the fracture area, allowing visualization of the outer and inner mandibular cortices. To document these fracture features beyond topography the alphanumeric codes are supplied with distinctive appendices. This level 3 tutorial is accompanied by a brief survey of the peculiarities of the edentulous atrophic mandible. Illustrations and a few case examples serve as instruction and reference to improve the understanding and application of the presented features. PMID:25489389

Mechanical implications of the mandibular coronoid process morphology in Neandertals.

PubMed

Marom, Assaf; Rak, Yoel

2018-06-01

Among the diagnostic features of the Neandertal mandible are the broad base of the coronoid process and its straight posterior margin. The adaptive value of these (and other) anatomical features has been linked to the Neandertal's need to cope with a large gape. The present study aims to test this hypothesis with regard to the morphology of the coronoid process. This admittedly simple, intuitive hypothesis was tested here via a comparative finite-element study of the primitive versus modified state of the coronoid process, using two-dimensional models of the mandible. Our simulations demonstrate that a large gape has an unfavorable effect on the primitive state of the coronoid process: the diagonal, almost horizontal, component of the temporalis muscle resultant (relative to the long axis of the coronoid process) bends the process in the sagittal plane. Furthermore, we show that the modification of the coronoid process morphology alone reduces the process' bending in a wide gape increasing the compression to tension ratio. These results provide indirect evidence in support of the hypothesis that the modification of the coronoid process in Neandertals is necessary for enabling their mandible to cope with a large gape. © 2018 Wiley Periodicals, Inc.

Phosphaturic mesenchymal tumor, mixed connective tissue variant, of the mandible: report of a case and review of the literature.

PubMed

Woo, Victoria L; Landesberg, Regina; Imel, Erik A; Singer, Steven R; Folpe, Andrew L; Econs, Michael J; Kim, Taeyun; Harik, Lara R; Jacobs, Thomas P

2009-12-01

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome that results in renal phosphate wasting with hypophosphatemia. In most cases, the underlying cause of TIO is a small mesenchymal neoplasm that is often difficult to detect, resulting in delayed diagnosis. One such neoplasm is the phosphaturic mesenchymal tumor, mixed connective tissue variant (PMTMCT), an unusual entity with unique morphologic and biochemical features. Most of these tumors are found at appendicular sites with only rare cases reported in the jaws. We describe a PMTMCT involving the mandible in a patient with a protracted history of osteomalacia. A review of the current literature is provided with emphasis on the clinical and histologic features, etiopathogenesis, and management of PMTMCT in the setting of TIO.

Phosphaturic mesenchymal tumor, mixed connective tissue variant, of the mandible: Report of a case and review of the literature

PubMed Central

Woo, Victoria L.; Landesberg, Regina; Imel, Erik A.; Singer, Steven R.; Folpe, Andrew L.; Econs, Michael J.; Kim, Taeyun; Harik, Lara R.; Jacobs, Thomas P.

2009-01-01

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome that results in renal phosphate wasting with hypophosphatemia. In most cases, the underlying cause of TIO is a small mesenchymal neoplasm that is often difficult to detect, resulting in delayed diagnosis. One such neoplasm is the phosphaturic mesenchymal tumor, mixed connective tissue variant (PMTMCT), an unusual entity with unique morphologic and biochemical features. The majority of these tumors are found at appendicular sites with only rare cases reported in the jaws. We describe a PMTMCT involving the mandible in a patient with a protracted history of osteomalacia. A review of the current literature is provided with emphasis on the clinical and histologic features, etiopathogenesis, and management of PMTMCT in the setting of TIO. PMID:19828339

A case of Sotos syndrome treated with distraction osteogenesis in maxilla and mandible.

PubMed

Takano, Masayuki; Kasahara, Kiyohiro; Ogawa, Chiharu; Katada, Hidenori; Sueishi, Kenji

2012-01-01

Sotos syndrome is inherited in an autosomal-dominant manner and is characterized by increased birth weight, excessive growth, advanced bone age, and distinctive facial features, including dolichocephaly, hypertelorism, and a prominent mandible. We treated a jaw deformity due to Sotos syndrome consisting of malocclusion due to a narrow maxillary dental arch and mandibular retrusion from hypoplasia of the rami. The patient was a 17-year-old man. Malocclusion due to a narrow maxillary dental arch and mandibular retrusion was diagnosed. Rapid maxillary expansion with Lines corticotomy and mandibular advancement with distraction osteogenesis were performed. The maxilla was expanded laterally a total of 3 mm and the mandible prolonged 12 mm in the posterior area of the mandibular body. Subsequently, orthodontic treatment was continued. At present, 5 years after surgery, occlusion remains good and stable.

[Fixed appliance therapy in patients with impaired short-circuit in the anterior part of the maxilla].

PubMed

Matthews-Brzozowska, Teresa; Pobol-Aidi, Małgorzata; Cudziło, Dorota

2015-03-01

Malocclusion in the anterior segment of maxilla and mandible are easily visible not only for dentists but also for the doctors of other specialties. Early diagnosis and appropriate therapy is important not only for occlusion but also for aesthetic reasons. The aim of the paper is to evaluate the anterior segment of maxilla and mandible in patients with malocclusion in this part and correct occlusion in the lateral segments. Medical documentation, i.e. medical history, extra- and intraoral radiograms, diagnostic casts, panoramic and lateral cephalometric radiograms of patients aged 7-12 diagnosed with malocclusion in the anterior segment of maxilla and mandible and who were treated with a fixed sectional appliance and facemask was analyzed. Descriptive and cephalometric features were analyzed before (T1) and after (T2) the treatment in 25 children. The differences between the status before and after the treatment, and the extent of change between T1 and T2 were analyzed. Statistical analysis of mean values of selected metrical features before (at T1) and after (at T2) the treatment has revealed that all metrical features concerning soft, bony and dental tissues determining the facial profile, the shape of the bony and dental structures have changed and have reached values which are closer to the norm for the population for selected features. The changes were statistically significant (p<0.0001). Treatment with fixed appliances segment facemask resulted in statistically significant improvement in the parameters investigated, which demonstrates the applicability of this therapy in the treatment of anterior maxillary segment in patients with mixed dentition. © 2015 MEDPRESS.

Odontogenic cysts: demographic profile in a Brazilian population over a 38-year period.

PubMed

de Souza, Lélia-Batista; Gordón-Núñez, Manuel-Antonio; Nonaka, Cassiano-Francisco-Weege; de Medeiros, Marcell-Costa; Torres, Tabita-Fernandes; Emiliano, Gustavo-Barbalho-Guedes

2010-07-01

To determine the distribution of odontogenic cysts diagnosed histologically over a period of 38 years in a Brazilian population according to age, gender and site affected and to compare these data with previously reported studies from other countries. A total of 1019 cases of odontogenic cysts diagnosed between 1970 and 2007 were studied. Clinical features obtained from the patient records and microscope slides were reviewed according to the 1992 World Health Organization classification. The mean age was 31.0 years, and there was a predominance of females. The most frequent odontogenic cysts were radicular cysts (61.4%), followed by dentigerous cysts (20.1%) and odontogenic keratocysts (6.4%). Radicular cysts were more frequent in females (62.0%), and the maxillary teeth were the site most commonly involved (63.05%). The peak incidence of dentigerous cysts occurred in the second decade of life, with the posterior region of the mandible being the site most affected (46.3%), followed by the anterior region of the maxilla (27.8%). Odontogenic keratocysts showed a peak incidence between the third and fourth decades of life and predominance among females. The posterior region of the mandible was the site most frequently affected (65.6%). The present results showed a similar frequency of odontogenic cysts in this Brazilian population and other populations around the world, with inflammatory cysts being identified as the most frequent odontogenic cyst. Radicular cysts, dentigerous cysts, and odontogenic keratocysts are the most common cystic lesions, accounting for 87.9% of all odontogenic cysts.

An Automatic Registration Algorithm for 3D Maxillofacial Model

NASA Astrophysics Data System (ADS)

Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng

2016-09-01

3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.

Microdeletion of 19p13.3 in a girl with Peutz-Jeghers syndrome, intellectual disability, hypotonia, and distinctive features.

PubMed

Kuroda, Yukiko; Saito, Toshiyuki; Nagai, Jun-Ichi; Ida, Kazumi; Naruto, Takuya; Masuno, Mitsuo; Kurosawa, Kenji

2015-02-01

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disease characterized by gastrointestinal polyposis and mucocutaneous pigmentation. Germline point mutations in the serine/threonine kinase 11 (STK11) have been identified in about 70% of patients with PJS. Only a few large genomic deletions have been identified. We report on a girl with PJS and multiple congenital anomalies. She had intellectual disability, umbilical hernia, bilateral inguinal hernias, scoliosis, and distinct facial appearance including prominent mandible, smooth philtrum, and malformed ears. She developed lip pigmentation at the age of 12 years but had no gastrointestinal polyps. Array comparative genomic hybridization revealed an approximately 610 kb deletion at 19p13.3, encompassing STK11. Together with previous reports, the identification of common clinical features suggests that microdeletion at 19p13.3 encompassing STK11 constitutes a distinctive phenotype. © 2014 Wiley Periodicals, Inc.

Massive dedifferentiated chondrosarcoma affecting whole mandible with high recurrence potential

PubMed Central

Mishra, Niranjan; Singh, Akhilesh Kumar; Agrawal, Rahul; Singh, Shreya

2015-01-01

Chondrosarcomas (CS) are slow-growing, malignant mesenchymal tumors characterized by the formation of cartilage by the tumor cells. Benign cartilage-producing tumors within the jaws are extremely uncommon, but most ultimately prove to represent low-grade CS. In the maxillofacial region, the maxilla is more commonly affected than the mandible, it comprises less than 2% of all jaw tumors. Clinically, the tumor presents as a swelling that may be painful and cause loosening of the involved teeth, with widening of the periodontal ligament space. The treatment of such lesions is wide surgical excision with regular follow up. The present report discusses the case of a 55-year-old female patient with massive multiple recurring dedifferentiated CS of mandible. PMID:27390502

Anthropometrics of mental foramen in dry dentate and edentulous mandibles in Coastal Andhra population of Andhra Pradesh State.

PubMed

Moogala, Srinivas; Sanivarapu, Sahitya; Boyapati, Ramanarayana; Devulapalli, Narasimha Swamy; Chakrapani, Swarna; Kolaparthy, Laxmikanth

2014-07-01

The aim of this study is to determine the morphological features and morphometrics of mental foramen with reference to surrounding anatomical landmarks in Coastal Andhra population of Andhra Pradesh State. Two-hundred and nineteen dry dentate and edentulous mandibles are examined in this study. Out of these 127 were dentate and 92 were edentulous. Various morphological and morphometrical parameters were measured by using digital Vernier caliper, metallic wire and metallic scale on both the right and left sides. In the present study, the distance between most anterior margin of mental foramen and posterior border of ramus of the mandible is [MF-PR], MF-PR is 69.61 ± 6.03 mm on the right side and is 69.17 ± 6. 0 mm on left side in dentate mandible. In edentulous type, MF-PR is 68.39 ±6.4 mm on right side and 68.81 ± 6.55 mm on left side. In the present study, the distance between symphysis menti and most anterior margin of mental foramen [MF-SM] in dentate mandible is 28.24 ± 5.09 mm on right side and is 27.45 ± 3.7 mm on left side. In edentulous mandible (MF-SM) is 28.51 ± 4.5 mm on right side and on left side is 27.99 ± 4.50 mm. Acquiring the knowledge and importance of anatomy of mental foramen is helpful in avoiding neurovascular complications, during regional anesthesia, peri apical surgeries, nerve repositioning and dental implant placement.

Tensile force produced by a lipoma in the masseteric space possibly causing hyperostosis of the angle of the mandible.

PubMed

Zhang, Feng; Xie, Zhi-jian; Ge, Wei-li; Li, Sheng-lai; Li, Yi-ning

2009-09-01

A lipoma is a benign tumor which may occur in the adipose tissue of any part of the body. The tumor is most commonly found on the trunk and extremities. Although it is the most common tumor of mesenchymal origin in the head and neck, its incidence is relatively rare. Lipoma of the head and neck is usually located in subcutaneous tissue. It is rarely deep seated with osseous involvement and rarely occurs in children, especially below the age of 10. The case of a painless mass of one-year history in the right parotidomasseteric region of an eight-year-old boy is presented. The mass was revealed to be a classical lipoma in the masseteric space, possibly causing hyperostosis of the angle of the mandible. After removal of the mass and a spherical protuberance in the angle of the mandible, the boy recovered and no recurrence was noted after one-year follow-up. Hyperostosis is a rare phenomenon with lipoma. In this case, the hypothesis was posed that the tensile force produced by the lipoma in the masseteric space possibly caused hyperostosis of the angle of the mandible. To the authors' knowledge, a classical lipoma arising from the deep fascial space resulting in osseous change has not been described in the literature before.

Is Homo heidelbergensis a distinct species? New insight on the Mauer mandible.

PubMed

Mounier, Aurélien; Marchal, François; Condemi, Silvana

2009-03-01

The discovery of new fossils in Africa, Asia, and Europe, and the recognition of a greater diversity in the middle Pleistocene fossil record, has led to a reconsideration of the species Homo heidelbergensis. This nomen, formulated by Schoetensack in 1908 to describe the Mauer jaw (Germany), was almost forgotten during most of the past century. Numerous fossils have been attributed to it but no consensus has arisen concerning their classification. The holotype anatomical traits are still poorly understood, and numerous fossils with no mandibular remains have been placed in the taxon. Some researchers propose H. heidelbergensis as an Afro-European taxon that is ancestral to both modern humans and Neandertals whereas others think it is a strictly European species that is part of the Neandertal lineage. We focus on the validity of H. heidelbergensis, using the traditional basis of species recognition: anatomical description. We provide a comparative morphological analysis using 47 anatomical traits of 36 Pleistocene fossils from Africa, Asia, and Europe and 35 extant human mandibles. We re-examine the mandibular features of Mauer and discuss the specimen's inclusion in H. heidelbergensis, as well as alternative evolutionary theories. To lend objectivity to specimen grouping, we use multiple correspondence analysis associated with hierarchical classification that creates clusters corresponding to phenetic similarities between jaws. Our phenetic and comparative morphological analyses support the validity of H. heidelbergensis as a taxon. A set of morphological features can be statistically identified for the definition of the species. Some traits can be used to delimit H. heidelbergensis in an evolutionary framework (e.g., foramina mentale posteriorly positioned, horizontal retromolar surface). Those traits are also present on African (e.g., Tighenif) and European (e.g., Sima de los Huesos) specimens that show a close relationship with the Mauer mandible. Therefore, the definition of H. heidelbergensis is more precise and mainly supports the theory of an Afro-European taxon, which is the last common ancestor of H. neanderthalensis and H. sapiens. However, the results of this study fail to entirely discount the hypothesis that considers H. heidelbergensis as a chronospecies leading to the Neandertals.

Maxillofacial Injuries in Children: A 10 year Retrospective Study.

PubMed

Kambalimath, H V; Agarwal, S M; Kambalimath, Deepashri H; Singh, Mamta; Jain, Neha; Michael, P

2013-06-01

Fractures of facial bones in children are relatively uncommon although both children and adults are subjected to similar types of injuries. This study aims to evaluate the epidemiology of facial bone fractures among children under 14 years, their management and outcome. This retrospective study included maxillofacial injuries treated in 112 children under 14 years admitted due to maxillofacial injuries during the period from 2001 to 2011. Of them ten (8.93 %) were below 5 years, 44 (39.29 %) between 6 and 10 years and 58 (51.78 %) between 11 and 14 years of age. Male to female ratio was 1.8:1. Fall from a height was the most common etiology. The most common jaw involved in the fracture was the mandible. Conservative management was done in 83.04 % of cases and open reduction and internal fixation was performed in 16.96 % of cases. Five (4.46 %) cases accounted for post-operative wound infection. Fracture of the mandible is the most common maxillofacial injury in children, most often caused by fall from a height. The osteogenic potential of the mandible in children leads to conservative management of these fractures. Opportunities for prevention of maxillofacial trauma should be taken into consideration by parents and care takers.

Mesodermal Tbx1 is required for patterning the proximal mandible in mice

PubMed Central

Aggarwal, Vimla S.; Carpenter, Courtney; Freyer, Laina; Liao, Jun; Petti, Marilena; Morrow, Bernice E.

2010-01-01

Defects in the lower jaw, or mandible, occur commonly either as isolated malformations or in association with genetic syndromes. Understanding its formation and genetic pathways required for shaping its structure in mammalian model organisms will shed light into the pathogenesis of malformations in humans. The lower jaw is derived from the mandibular process of the first pharyngeal arch (MdPA1) during embryogenesis. Integral to the development of the mandible, is the signaling interplay between Fgf8 and Bmp4 in the rostral ectoderm and their downstream effector genes in the underlying neural crest derived mesenchyme. The non-neural crest MdPA1 core mesoderm is needed to form muscles of mastication, but its role in patterning the mandible is unknown. Here, we show that mesoderm specific deletion of Tbx1, a T- box transcription factor and gene for velo-cardio-facial/DiGeorge syndrome, results in defects in formation of the proximal mandible by shifting expression of Fgf8, Bmp4 and their downstream effector genes in mouse embryos at E10.5. This occurs without significant changes in cell proliferation or apoptosis at the same stage. Our results elucidate a new function for the non-neural crest core mesoderm and specifically, mesodermal Tbx1, in shaping the lower jaw. PMID:20501333

Cemento-ossifying fibroma occurring in an elderly patient. A case report and a review of literature

PubMed Central

Dalghous, Abdulbaset; Alkhabuli, Juma O

2007-01-01

Cemento-ossifying fibromas (COF) are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adults between the third and fourth decade of life. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses, commonly in the premolar/molar region of the mandible. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumour may grow quite extensively, thus the term aggressive is some times applied. Their clinical, radiographical and histopathological features and those of fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis, and treatment. The histopathology is composed of fibrous tissues with calcified structures resembling bone or cementum. Surgical enucleation or resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. This case report presents a case of COF in 70 years old female patient that was asymptomatic. Clinically, there was an expansion of the buccal plate but not the lingual plate of the right mandible. The covering mucosa was normal and there was no tenderness or paraesthesia. Radiographically, the lesion extends superio-inferiory from the alveolar ridge to the area of inferior dental canal and mesiodistally from the premolar region to the retro-molar area. The lesion was of mixed radiolucent densities. The patient was followed up periodically for 5 years without any treatment. The patient continued to be asymptomatic with minimum changes. Occurrence of cemento-ossifying fibroma in patients over 60 years of age is unusual and had not been reported. The clinical, radiographic, histopathology and literature review are discussed. PMID:21503260

Cemento-ossifying fibroma occurring in an elderly patient. A case report and a review of literature.

PubMed

Dalghous, Abdulbaset; Alkhabuli, Juma O

2007-06-01

Cemento-ossifying fibromas (COF) are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adults between the third and fourth decade of life. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses, commonly in the premolar/molar region of the mandible. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumour may grow quite extensively, thus the term aggressive is some times applied. Their clinical, radiographical and histopathological features and those of fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis, and treatment. The histopathology is composed of fibrous tissues with calcified structures resembling bone or cementum. Surgical enucleation or resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. This case report presents a case of COF in 70 years old female patient that was asymptomatic. Clinically, there was an expansion of the buccal plate but not the lingual plate of the right mandible. The covering mucosa was normal and there was no tenderness or paraesthesia. Radiographically, the lesion extends superio-inferiory from the alveolar ridge to the area of inferior dental canal and mesiodistally from the premolar region to the retro-molar area. The lesion was of mixed radiolucent densities. The patient was followed up periodically for 5 years without any treatment. The patient continued to be asymptomatic with minimum changes. Occurrence of cemento-ossifying fibroma in patients over 60 years of age is unusual and had not been reported. The clinical, radiographic, histopathology and literature review are discussed.

En bloc resection of huge cemento-ossifying fibroma of mandible: avoiding lower lip split incision.

PubMed

Ayub, Tahera; Katpar, Shahjahan; Shafique, Salman; Mirza, Talat

2011-05-01

Cemento-ossifying Fibroma (COF) is an osteogenic benign neoplasm affecting the jaws and other craniofacial bones. It commonly presents as a progressively slow growing pathology, which can sometimes attain an enormous size, causing facial deformity. A case of a huge cemento-ossifying fibroma, appearing as a mandibular dumbell tumour in a male patient is documented, which caused massive bone destruction and deformity. It was surgically removed by performing en bloc resection of mandible avoiding the splitting of lower lip incision technique, thereby maintaining his normal facial appearance.

Mandible shape in hybrid mice.

PubMed

Renaud, Sabrina; Alibert, Paul; Auffray, Jean-Christophe

2009-09-01

Hybridisation between closely related species is frequently seen as retarding evolutionary divergence and can also promote it by creating novel phenotypes due to new genetic combinations and developmental interactions. We therefore investigated how hybridisation affects the shape of the mouse mandible, a well-known feature in evo-devo studies. Parental groups corresponded to two strains of the European mouse sub-species Mus musculus domesticus and Mus musculus musculus. Parents and hybrids were bred in controlled conditions. The mandibles of F(1) hybrids are mostly intermediate between parental phenotypes as expected for a complex multigenic character. Nevertheless, a transgressive effect as well as an increased phenotypic variance characterise the hybrids. This suggests that hybridisation between the two subspecies could lead to a higher phenotypic variance due to complex interactions among the parental genomes including non-additive genetic effects. The major direction of variance is conserved, however, among hybrids and parent groups. Hybridisation may thus play a role in the production of original transgressive phenotypes occurring following pre-existing patterns of variance.

[Stress analysis of the mandible by 3D FEA in normal human being under three loading conditions].

PubMed

Sun, Jian; Zhang, Fu-qiang; Wang, Dong-wei; Yu, Jia; Wang, Cheng-tao

2004-02-01

The condition and character of stress distribution in the mandibular in normal human being during centric, protrusive, laterotrusive occlusion were analysed. The three-dimensional finite element model of the mandibular was developed by helica CT scanning and CAD/CAM software, and three-dimensional finite element stress analysis was done by ANSYS software. Three-dimensional finite element model of the mandibular was generated. Under these three occlusal conditions, the stress of various regions in the mandible were distributed unequally, and the stress feature was different;while the stress of corresponding region in bilateral mandibular was in symmetric distribution. The stress value of condyle neck, the posterior surface of coronoid process and mandibular angle were high. The material properties of mandible were closely correlated to the value of stress. Stress distribution were similar according to the three different loading patterns, but had different effects on TMJ joint. The concentrated areas of stress were in the condyle neck, the posterior surface of coronoid process and mandibular angle.

A paradoxical presentation of rickets and secondary osteomyelitis of the jaw in Type II autosomal dominant osteopetrosis: Rare case reports.

PubMed

Jayachandran, S; Kumar, M Suresh

2016-01-01

Osteopetrosis is a rare genetic bone disorder arising due to a defect in the differentiation or function of osteoclast which results in a generalized increase in bone mass. Osteomyelitis is one of the most common complications because of decreased bone marrow function and compromised blood supply. Radiologist plays a vital role in diagnosing osteopetrosis. Here, we present two cases of autosomal dominant osteopetrosis Type II (ADO II) with secondary osteomyelitis changes which were reported to our department. One of these two cases presented with secondary osteomyelitis in both maxilla and mandible and features of rickets, which is very rarely seen in ADO II. To the best of our knowledge, the presentation of rickets with ADO is the first of its kind to be reported. In this paper, we describe the clinical and radiological features leading to the diagnosis of ADO in these two patients. Further, a review of the literature regarding ADO is discussed.

Cap’n’collar differentiates the mandible from the maxilla in the beetle Tribolium castaneum

PubMed Central

2012-01-01

Background The biting mandible of the arthropods is thought to have evolved in the ancestor of the insects, crustaceans and myriapods: the Mandibulata. A unique origin suggests a common set of developmental genes will be required to pattern the mandible in different arthropods. To date we have functional studies on patterning of the mandibular segment of Drosophila melanogaster showing in particular the effects of the gene cap’n’collar (cnc), however, the dipteran head is far from representative of insects or of more distantly related mandibulates; Drosophila does not even possess a mandibular appendage. To study the development of a more representative insect mandible, we chose the red flour beetle Tribolium castaneum and investigated the function of the Tribolium orthologs of cap’n’collar (Tc-cnc) and the Hox gene Deformed (Tc-Dfd). In order to determine the function of Tc-cnc and Tc-Dfd, transcripts were knocked down by maternal RNA interference (RNAi). The effects of gene knockdown were examined in the developing embryos and larvae. The effect of Tc-cnc and Tc-Dfd knockdown on the expression of other genes was determined by using in situ hybridization on Tribolium embryos. Results Our analyses show that Tc-cnc is required for specification of the identity of the mandibular segment of Tribolium and differentiates the mandible from maxillary identity. Loss of Tc-cnc function results in a transformation of the mandible to maxillary identity as well as deletion of the labrum. Tc-Dfd and the Tribolium homolog of proboscipedia (Tc-mxp = maxillopedia), Hox genes that are required to pattern the maxillary appendage, are expressed in a maxilla-like manner in the transformed mandible. Tribolium homologs of paired (Tc-prd) and Distal-less (Tc-Dll) that are expressed in the endites and telopodites of embryonic appendages are also expressed in a maxilla-like manner in the transformed mandible. We also show that Tc-Dfd is required to activate the collar of Tc-cnc expression in the mandibular segment but not the cap expression in the labrum. Tc-Dfd is also required for the activation of Tc-prd in the endites of the mandible and maxillary appendages. Conclusions Tc-cnc is necessary for patterning the mandibular segment of Tribolium. Together, Tc-cnc and Tc-Dfd cooperate to specify mandibular identity, as in Drosophila. Expression patterns of the homologs of cnc and Dfd are conserved in mandibulate arthropods suggesting that the mandible specifying function of cnc is likely to be conserved across the mandibulate arthropods. PMID:23114106

The Role of a Conservative Minimal Interventional Management Protocol in the Fractures of the Dentate Portion of the Adult Mandible

PubMed Central

Krishnan, Balasubramanian

2015-01-01

Mandibular fractures are commonly encountered by the maxillofacial surgeon. Maxillomandibular fixation (MMF) and open reduction and internal fixation (ORIF), or a combination of both, are the accepted standard treatments. This study aims to assess the role of a conservative minimal intervention protocol in the management of undisplaced/minimally displaced fractures of the dentate portion of the adult mandible and the complications associated with such minimalistic intervention. Thirty-four patients with undisplaced/minimally displaced fractures of the dentate portion of the adult mandible were advised to restrict mouth opening and limit themselves to a soft diet for a minimum of 4 weeks. All patients were advised follow-up at regular intervals for at least 3 months. Five patients were lost to follow-up. Symphysis and parasymphysis fractures were the most common fracture locations. Fourteen patients needed tension band stabilization with a mandibular arch bar/bridle wiring and three patients required extraction of luxated teeth. All patients showed satisfactory healing except three in whom additional intervention (ORIF) was performed. The improvement in mouth opening was statistically significant. Complications were seen more frequently among smokers and alcoholics. For patients with minimally displaced mandibular fractures, it is necessary to consider if the perceived benefits of intervention justify the associated added costs and possible complications. Patients have to be fully informed about the possible complications while using this minimal intervention protocol. This study concludes that a conservative minimal intervention management protocol for such fractures of the dentate portion of the mandible can produce satisfactory results. PMID:26889344

Experiment K-310: The effect of spaceflight on osteogenesis and dentinogenesis in the mandibles of rats

NASA Technical Reports Server (NTRS)

Simmons, D. J.; Russell, J. E.; Winter, F.; Rosenberg, G. D.; Walker, W. V.

1981-01-01

Normal rates of dentinogenesis and osteogenesis in the body of the mandible were observed. The total calcium, inorganic phosphorus and hydroxyproline levels in the jaws and incisors of the flight rats were normal. Gravity density fractionation studies suggested, however, that spaceflight caused a delay in the normal maturation of bone mineral and matrix; normal values were reestablished by 6 days postflight. The teeth were spared. The circadian and ultradian patterns of dentin calcification were normal during spaceflight and recovery periods, but the enamel rhythms displayed a greater amplitude of sulfur concentrations and this abnormal calcium to sulfur ratios only during exposure to zero gravity. The rat mandible and teeth do not suffer the deficits of bone formation common to weight bearing parts of the skeleton during spaceflight. The only derangements detected were in the quality of the matrix and mineral moieties.

Short stature Revealing a Pycnodysostosis: A Case Report

PubMed Central

Aynaou, Hayat; Skiker, Imane; Latrech, Hanane

2016-01-01

Introduction: Pycnodysostosis is a rare genetic disease characterized by osteosclerosis and bone fragility. The clinical aspects are varied including short stature, acro-osteolysis of distal phalanges, and dysplasia of the clavicles. Oral and maxillofacial manifestations of this disease are very clear. The head is usually large, a beaked nose, obtuse mandibular angle, and both maxilla and mandible are hypoplastic. Dental abnormalities are common. We report a case with the typical clinical and radiological characteristics of the Pycnodysostosis associated with a conductive hearing loss, an association rarely reported. Case Presentation: A 12-year-female was admitted in our institute for short stature with a dysmorphic facies for evaluation. The patient reported a history of multiple fractures of the long bones after a trivial fall. On physical examination, she had the following features: short stature, limited mouth opening, short hands and feet with dysplastic nails; frontal and occipital bossing; and hypoplasia of the maxilla and mandible. Examination of the mouth: grooved palate, caries of the teeth, impacted and malposed teeth, persistent deciduous teeth and missing teeth. Laboratory investigations were normal. The radiographic examination showed a generalized increase in the bone density, slight condensation of the skull base and a very open mandibular angle. X-rays showed tapered phalanges with acro-osteolysis of the distal phalanges. A symptomatic treatment was proposed based on fracture prevention, oral hygiene, frequent dental visits and psychiatric support. Conclusion: The clinical and radiological features are the bases for the diagnosis of this disease. It is important to make the diagnosis as early as possible in order to plan the treatment and to provide a better life quality to the patients. PMID:27703936

Features of lateral cephalograms associated with difficult laryngoscopy in Japanese children undergoing oral and maxillofacial surgery.

PubMed

Kohjitani, Atsushi; Miyawaki, Takuya; Miyawaki, Shouichi; Nakamura, Norifumi; Iwase, Yoko; Nishihara, Kazuhide; Ohno, Sachi; Shimada, Masahiko; Sugiyama, Kazuna

2013-11-01

Difficult laryngoscopy and tracheal intubation are occasionally encountered in children with congenital anomalies or micrognathia. However, no study has elucidated anatomical etiology in relation to craniofacial development. Two hundred ten patients aged 8 months-18 years were analyzed. We analyzed the lateral cephalograms of: (i) eight patients in whom laryngoscopy was anticipated as difficult before anesthesia and who were unable to be intubated by direct laryngoscopy and needed fiberoptic bronchoscopy (group A); (ii) 11 patients in whom laryngoscopy was anticipated as difficult before anesthesia but who were able to be intubated by direct laryngoscopy (group B); and (iii) 191 patients in whom laryngoscopy was anticipated as easy before anesthesia and was actually found to be easy (group C). Eight cephalometric parameters were measured and age-parameter relationships were plotted. Logistic regression analysis was performed to characterize group A children for each of the cephalometric variables. Apparently insufficient growth of the mandible was observed in the group A children. Furthermore, the group A children of aged <4 years had undeveloped maxilla, longer mandibular plane-hyoid distances (≥1.3 cm), and deeper depth of the oropharynx; those of aged ≥4 years showed increased inclination of the mandible (sella-nasion plane to mandibular plane angle of ≥46.5°). Difficult laryngoscopy and tracheal intubation are expected in children aged <4 years with lower-positioned hyoid bone caused by caudal larynx as well as undeveloped maxilla and mandible, and in those aged ≥4 years with increased inclination of the mandible as well as undeveloped mandible. © 2013 John Wiley & Sons Ltd.

Characterization of the Correct Mandibular Premolar Region for Delayed Dental Implantation in Beagle Dogs.

PubMed

Xie, Chenxi; Fu, Xiaoming; Xu, Ling; Xu, Sheng

2018-05-01

For delayed dental implantation into the mandible, the implant size should be chosen according to the characteristics of that bone. This study investigated anatomic features of the mandible in beagle dogs, to develop recommendations regarding the correct implantation region and available bone area for delayed dental implantation surgery. We used 20 healthy male beagle dogs to create delayed dental implantation models. The dogs' mandibles underwent cone beam CT (CBCT) imaging; the locations of the middle mental foramen and canine root apex were measured on CBCT images. The dogs then were euthanized and their mandibles measured by using a digital vernier caliper. In addition, the correct implantation region and available bone areas were evaluated. The data obtained by using the 2 measuring methods were compared statistically. The results showed that the positions of the middle mental foramen and canine root apex were relatively fixed, with little variation. The implantation and available bone regions showed little variation among dogs and did not differ significantly between the 2 measuring methods. In conclusion, the correct implantation region (mean ± 1 SD) in the beagle mandible for delayed dental implantation surgery was 17.53 ± 0.46 mm in width. The recommended available bone areas (height × width) were 7.22 ± 0.68 mm × 5.32 ± 0.49 mm (P2), 8.21 ± 0.71 mm × 5.81 ± 0.56 mm (P3), and 9.17 ± 0.65 mm × 6.39 ± 0.56 mm (P4) in the premolar region.

Pattern of dental development in Hominid XVIII from the Middle Pleistocene Atapuerca-Sima de los Huesos site (Spain).

PubMed

Bermudez De Castro, J M; Rosas, A

2001-04-01

. We describe the pattern of dental development of Hominid XVIII from the Middle Pleistocene Sima de los Huesos (SH) site of the Sierra de Atapuerca (Burgos, Spain). As expected, this pattern is similar to that of modern humans. A delay of development of the lower and upper canines was observed. In contrast, the relative advanced development of the lower second molars and, especially, the upper and lower third molars is noteworthy. This latter feature seems to be common in Pleistocene hominids, and suggests that the pattern of dental development evolved in the genus Homo during the Pleistocene. In European Middle Pleistocene hominids, this pattern probably was facilitated by the extra space available in the mandible and maxilla for developing teeth. Copyright 2001 Wiley-Liss, Inc.

Management of fractures of the mandibular body and symphysis.

PubMed

Goodday, Reginald H B

2013-11-01

Mandibular fracture, specifically in the symphysis and body regions combined, is the most common facial fracture requiring hospitalization in North America. The primary treatment objective is to restore form and function by achieving anatomic reduction and placing fixation that eliminates mobility of the bone fragments. Several treatment options and surgical techniques are available for performing closed or open reduction. Special considerations are necessary when treating pediatric patients and fractures of the edentulous mandible. Complications relating to the tooth and denture-bearing regions of the mandible include infection, nonunion, and neurosensory changes. Copyright © 2013 Elsevier Inc. All rights reserved.

Richieri-Costa-Pereira syndrome: Expanding its phenotypic and genotypic spectrum.

PubMed

Bertola, D R; Hsia, G; Alvizi, L; Gardham, A; Wakeling, E L; Yamamoto, G L; Honjo, R S; Oliveira, L A N; Di Francesco, R C; Perez, B A; Kim, C A; Passos-Bueno, M R

2018-04-01

Richieri-Costa-Pereira syndrome is a rare autosomal recessive acrofacial dysostosis that has been mainly described in Brazilian individuals. The cardinal features include Robin sequence, cleft mandible, laryngeal anomalies and limb defects. A biallelic expansion of a complex repeated motif in the 5' untranslated region of EIF4A3 has been shown to cause this syndrome, commonly with 15 or 16 repeats. The only patient with mild clinical findings harbored a 14-repeat expansion in 1 allele and a point mutation in the other allele. This proband is described here in more details, as well as is his affected sister, and 5 new individuals with Richieri-Costa-Pereira syndrome, including a patient from England, of African ancestry. This study has expanded the phenotype in this syndrome by the observation of microcephaly, better characterization of skeletal abnormalities, less severe phenotype with only mild facial dysmorphisms and limb anomalies, as well as the absence of cleft mandible, which is a hallmark of the syndrome. Although the most frequent mutation in this study was the recurrent 16-repeat expansion in EIF4A3, there was an overrepresentation of the 14-repeat expansion, with mild phenotypic expression, thus suggesting that the number of these motifs could play a role in phenotypic delineation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Primary xanthoma of the mandible

PubMed Central

de Moraes Ramos-Perez, FM; de Pádua, JM; Silva-Sousa, YTC; de Almeida, OP; da Cruz Perez, DE

2011-01-01

Bone xanthomas are rare and are usually are associated with endocrine or metabolic diseases, mainly lipid disorders. In the absence of systemic diseases, the lesion is called a primary xanthoma. Primary mandibular xanthomas are extremely rare. The aim of this report is to describe the clinical and radiographic findings of a primary mandibular xanthoma, discussing the epidemiological features, pathogenesis and differential diagnosis. A 25-year-old man was referred for evaluation of a left mandibular lesion detected in a routine radiographic exam. Radiographically, there was a diffuse, unilocular and radiolucent lesion, with irregular margins located adjacent to the surface from the distal root of the left mandibular third molar. The lesion was excised under local anaesthesia. Microscopically, there were several cells with a foamy and granular cytoplasm and central small, round nuclei, similar to xanthomatous macrophages. No lipid disorders were diagnosed. According to these features, the diagnosis of primary mandibular xanthoma was established. In conclusion, xanthomas of the jaws are rare and all seem to be primary and occur exclusively in the mandible. PMID:21831981

Relationship between chin deviation and the position and morphology of the mandible in individuals with a unilateral cleft lip and palate

PubMed Central

Kim, Kyung-Seon; Park, Soo-Byung; Kim, Seong-Sik; Kim, Yong-Il

2013-01-01

Objective In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. Conclusions UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance. PMID:24015386

Peripheral giant cell granuloma of the mandibular condyle presenting as a preauricular mass.

PubMed

Ozcan, Cengiz; Apaydin, F Demir; Görür, Kemal; Apa, Duygu Düşmez

2005-03-01

Preauricular mass is a common symptom for patients presenting to the otorhinolaryngologist with parotid disease. Some rare extraparotid lesions, originating from the temporomandibular joint and the mandible itself, also share the same localization and therefore are to be taken into consideration for the differential diagnosis with parotid lesions. Giant cell granuloma (GCG) was first described by Jaffe in 1953. Peripheral GCG (PGCG) is an exophytic soft tissue lesion originating from the periodontal ligament and periosteum. It is located only within the oral cavity. Central GCG (CGCG) is an uncommon benign fibro-osseous lesion generally presenting as an expansible mass with cortical bone defect. It is generally located in the mandible. The brown tumor of hyperparathyroidism and giant cell tumor must be ruled out because of the microscopic similarities of these lesions. The first case of PGCG of the mandible condyle is presented, and attention is drawn to mandibular diseases for the differential diagnosis of the preauricular mass.

Intraosseous Schwannoma of the Maxilla Mimicking a Periapical Lesion: A Diagnostic Challenge

PubMed Central

Anekar, Jayaprasad; Raj, Achikanam Chirakkara; Patil, Uma Sambargi; Mustafa, Shabil Mohamed

2015-01-01

Schwannomas are a type of nerve sheath tumours predominant in the soft tissues of the head and neck. They commonly present as slow growing, painful swellings and may rarely be accompanied by paresthesia. Less than 1% of schwannomas are intraosseous with affliction to the mandible over maxilla. Only 13 cases of maxillary schwannomas have been reported till date. This article documents a rare case of intramaxillary schwannoma that was disclosed during an incidental radiographic examination. It also provides a review of the literature on central schwannomas affecting the maxilla which suggests its affliction to females in the second decade with equal preference to both anterior and posterior segments of the jaw. It also highlights that intraosseous schwannomas may be considered in the differential diagnosis of periapical lesions with nonspecific clinical and radiographic features. PMID:25954708

Prevalence of mandibular fractures reported at C.S.M.S.S Dental College, aurangabad from february 2008 to september 2009

PubMed Central

Ghodke, Monali H.; Bhoyar, Subhash C.; Shah, Seemit V.

2013-01-01

Aim: The aim of this study is to determine the etiology, frequency of mandibular fractures among different age and sex, to determine the frequency of anatomic distribution, and to report the different modalities of treatment provided to the patients reported at our institution from February 2008 to September 2009. Materials and Methods: All patients fulfilling the selection criteria and having mandible fracture were selected for the study. Patient information was collected by means of a medical data form specifically designed for the present study. The values were subjected to Z and Chi-square tests. Results: Out of 35 patients, thirty one were males (88.57%) and four were females (11.43%) with a male:female ratio of 8:1. We found a peak occurrence in young adults, aged 21-30 years (n = 15, 42.86%). In case of etiology of fracture, road traffic accidents (RTAs) was the most common (n = 25, 71.43%) and condyle was most frequently involved site (n = 19, 38.78%). In most (n = 16, 45.71%) of the patients, an open reduction and rigid internal fixation using bone plate and screws was done. Conclusion: In the present study, the prevalence of mandible fractures was more prevalent in male patients, especially during the 3rd decade of life. The most common cause was road traffic accident and the more frequently affected region was condyle of the mandible. Open reduction and rigid internal fixation using miniplates and screws was the most commonly used treatment. PMID:24778980

Malunited fracture of the body and condyle of the mandible : A Case Report.

PubMed

Yeluri, Ramakrishna; Baliga, Sudhindra; Munshi, Autar Krishen

2010-07-01

Mandibular fractures are the most common facial fractures seen in hospitalized children and their incidence increases with age. Treatment options include soft diet, intermaxillary fixation with eyelet wires, arch bars, circummandibular wiring, or stents. Alternative options include open reduction and internal fixation through either an intraoral or extraoral approach. Many factors complicate the management of pediatric mixed-dentition mandibular fractures: tooth eruption, short roots, developing tooth buds and growth issues. One major factor is the inherent instability of the occlusion in the mixed deciduous-permanent tooth phase. This case report documents a child in mixed dentition period with a complication arising due to direct fixation of the fractured mandible.

Primary extracranial meningioma of the mandible.

PubMed

Mosqueda-Taylor, Adalberto; Domínguez-Malagon, Hugo; Cano-Valdez, Ana-Maria; Montiel-Hernandez, Ana-Maria

2009-04-01

Meningiomas are benign tumors of mesodermal origin that arise from arachnoid cell clusters that penetrate the dura to form arachnoid villi. These neoplasms represent one of the most common neoplasms developing within the central nervous system and are usually located at points of entry of vessels and nerves through the dura. Extracranial meningiomas (EM) comprise only 2% of all meningiomas, and only six cases of primary EM of the jawbones have been described to date. They may arise as an extension of intracranial meningiomas or as primary tumors and may be clinically indistinguishable from other benign tumours of the jaws, as they usually present as a well-delineated unencapsulated tumors. In this article a case of primary intramandibular primary EM that appeared as a well-defined osteolytic radiolucent lesion of the jaw is reported. The salient clinico-pathological features of this case is compared to those previously reported in the literature and differential diagnosis and therapeutic considerations are discussed.

Opposable spines facilitate fine and gross object manipulation in fire ants

NASA Astrophysics Data System (ADS)

Cassill, Deby; Greco, Anthony; Silwal, Rajesh; Wang, Xuefeng

2007-04-01

Ants inhabit diverse terrestrial biomes from the Sahara Desert to the Arctic tundra. One factor contributing to the ants’ successful colonization of diverse geographical regions is their ability to manipulate objects when excavating nests, capturing, transporting and rendering prey or grooming, feeding and transporting helpless brood. This paper is the first to report the form and function of opposable spines on the foretarsi of queens and workers used during fine motor and gross motor object manipulation in the fire ant, Solenopsis invicta. In conjunction with their mandibles, queens and workers used their foretarsi to grasp and rotate eggs, push or pull thread-like objects out of their way or push excavated soil pellets behind them for disposal by other workers. Opposable spines were found on the foretarsi of workers from seven of eight other ant species suggesting that they might be a common feature in the Formicidae.

Unexpectedly rapid evolution of mandibular shape in hominins.

PubMed

Raia, P; Boggioni, M; Carotenuto, F; Castiglione, S; Di Febbraro, M; Di Vincenzo, F; Melchionna, M; Mondanaro, A; Papini, A; Profico, A; Serio, C; Veneziano, A; Vero, V A; Rook, L; Meloro, C; Manzi, G

2018-05-09

Members of the hominins - namely the so-called 'australopiths' and the species of the genus Homo - are known to possess short and deep mandibles and relatively small incisors and canines. It is commonly assumed that this suite of traits evolved in early members of the clade in response to changing environmental conditions and increased consumption of though food items. With the emergence of Homo, the functional meaning of mandible shape variation is thought to have been weakened by technological advancements and (later) by the control over fire. In contrast to this expectation, we found that mandible shape evolution in hominins is exceptionally rapid as compared to any other primate clade, and that the direction and rate of shape change (from the ape ancestor) are no different between the australopiths and Homo. We deem several factors including the loss of honing complex, canine reduction, and the acquisition of different diets may have concurred in producing such surprisingly high evolutionary rates. This study reveals the evolution of mandibular shape in hominins has strong morpho-functional and ecological significance attached.

Central Telangiectatic Osteosarcoma of the Mandible in a Paediatric Patient: A Rarity.

PubMed

Tomar, Divya; Dhillon, Manu; Thayath, Muhamad Nishad; Zaidi, Iram; Singh, Shikha

2016-12-01

Osteosarcoma (OS) involving the head and neck region is rare and is a diagnostic challenge due to its aggressive nature and varied presentations. Although OS constitute 40% to 60% of all bone tumours, only 10% of these occur in the head and neck region, most commonly in the maxilla and mandible. OS of the jaw bone has a different pattern and behaviour when compared to OS at other anatomic location. It occurs in a more elderly population, less aggressive and usually spreads locally rather than distant metastases. Telangiectatic Osteosarcoma (TOS) of jaws in a paediatric patient is still a very rare variant and till date only two cases have been reported in literature. Radiographic evaluation plays an important role as the clinical symptoms are not specific to the condition. Conventional radiography should always be supplemented by advanced imaging modalities for the diagnosis, which gives a three dimensional assessment and also prevents superimposition of surrounding structures. Early diagnosis and radical surgery are the keys to high survival rates. Herein, we present a third ever reported case of TOS occurring in mandible of a nine-year-old male patient.

Developmental changes in the skull morphology of common minke whales Balaenoptera acutorostrata.

PubMed

Nakamura, Gen; Kato, Hidehiro

2014-10-01

We investigated growth-related and sex-related morphological changes in the skulls of 144 North Pacific common minke whales Balaenoptera acutorostrata. Measurement was conducted at 39 points on the skull and mandible to extract individual allometric equations relating the length and zygomatic width of the skull. The results revealed no significant differences in skull morphology by sex except for width of occipital bone. The size relative to the skull of the anatomical parts involved in feeding, such as the rostrum and mandible, increased after birth. In contrast, the sensory organs and the anatomical regions involved in neurological function, such as the orbit, tympanic bullae, and foramen magnum, were fully developed at birth, and their relative size reduced over the course of development. This is the first study to investigate developmental changes in the skull morphology using more than 100 baleen whale specimens, and we believe the results of this study will contribute greatly to multiple areas of baleen whale research, including taxonomy and paleontology. © 2014 Wiley Periodicals, Inc.

The accuracy of ultrashort echo time MRI sequences for medical additive manufacturing.

PubMed

van Eijnatten, Maureen; Rijkhorst, Erik-Jan; Hofman, Mark; Forouzanfar, Tymour; Wolff, Jan

2016-01-01

Additively manufactured bone models, implants and drill guides are becoming increasingly popular amongst maxillofacial surgeons and dentists. To date, such constructs are commonly manufactured using CT technology that induces ionizing radiation. Recently, ultrashort echo time (UTE) MRI sequences have been developed that allow radiation-free imaging of facial bones. The aim of the present study was to assess the feasibility of UTE MRI sequences for medical additive manufacturing (AM). Three morphologically different dry human mandibles were scanned using a CT and MRI scanner. Additionally, optical scans of all three mandibles were made to acquire a "gold standard". All CT and MRI scans were converted into Standard Tessellation Language (STL) models and geometrically compared with the gold standard. To quantify the accuracy of the AM process, the CT, MRI and gold-standard STL models of one of the mandibles were additively manufactured, optically scanned and compared with the original gold-standard STL model. Geometric differences between all three CT-derived STL models and the gold standard were <1.0 mm. All three MRI-derived STL models generally presented deviations <1.5 mm in the symphyseal and mandibular area. The AM process introduced minor deviations of <0.5 mm. This study demonstrates that MRI using UTE sequences is a feasible alternative to CT in generating STL models of the mandible and would therefore be suitable for surgical planning and AM. Further in vivo studies are necessary to assess the usability of UTE MRI sequences in clinical settings.

Thin-plate spline analysis of craniofacial morphology in subjects with adenoid or tonsillar hypertrophy.

PubMed

Baroni, Michela; Ballanti, Fabiana; Polimeni, Antonella; Franchi, Lorenzo; Cozza, Paola

2011-04-01

To compare the skeletal features of subjects with adenoid hypertrophy with those of children with tonsillar hypertrophy using thin-plate spline (TPS) analysis. A group of 20 subjects (9 girls and 11 boys; mean age 8.4 ± 0.9 years) with adenoid hypertrophy (AG) was compared with a group of 20 subjects (10 girls and 10 boys; mean age 8.2 ± 1.1 years) with tonsillar hypertrophy (TG). Craniofacial morphology was analyzed on the lateral cephalograms of the subjects in both groups by means of TPS analysis. A cross-sectional comparison was performed on both size and shape differences between the two groups. AG exhibited statistically significant shape and size differences in craniofacial configuration with respect to TG. Subjects with adenoid hypertrophy showed an upward dislocation of the anterior region of the maxilla, a more downward/backward position of the anterior region of the mandibular body and an upward/backward displacement of the condylar region. Conversely, subjects with tonsillar hypertrophy showed a downward dislocation of the anterior region of the maxilla, a more upward/forward position of the anterior region of the mandibular body and a downward/forward displacement of the condylar region. Subjects with adenoid hypertrophy exhibited features suggesting a more retrognathic mandible while subjects with tonsillar hypertrophy showed features suggesting a more prognathic mandible. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Morphometric analysis of instar variation in Tenebrio molitor (Coleoptera: Tenebrionidae)

USDA-ARS?s Scientific Manuscript database

Measurements of head capsule, mandible, metanotum, and body weight were done on larvae of Tenebrio molitor L. (Coleoptera: Tenebrionide) from the second to the last instar. Instar number varied from 14 to 18, but 15 or 16 instars were the most common. The value of dimensional measurements was evalua...

Thin-plate spline analysis of craniofacial growth in Class I and Class II subjects.

PubMed

Franchi, Lorenzo; Baccetti, Tiziano; Stahl, Franka; McNamara, James A

2007-07-01

To compare the craniofacial growth characteristics of untreated subjects with Class II division 1 malocclusion with those of subjects with normal (Class I) occlusion from the prepubertal through the postpubertal stages of development. The Class II division 1 sample consisted of 17 subjects (11 boys and six girls). The Class I sample also consisted of 17 subjects (13 boys and four girls). Three craniofacial regions (cranial base, maxilla, and mandible) were analyzed on the lateral cephalograms of the subjects in both groups by means of thin-plate spline analysis at T1 (prepubertal) and T2 (postpubertal). Both cross-sectional and longitudinal comparisons were performed on both size and shape differences between the two groups. The results showed an increased cranial base angulation as a morphological feature of Class II malocclusion at the prepubertal developmental phase. Maxillary changes in either shape or size were not significant. Subjects with Class II malocclusion exhibited a significant deficiency in the size of the mandible at the completion of active craniofacial growth as compared with Class I subjects. A significant deficiency in the size of the mandible became apparent in Class II subjects during the circumpubertal period and it was still present at the completion of active craniofacial growth.

Clinico-radiographic study of odontogenic cysts at a tertiary care centre.

PubMed

Ali, Kamran; Munir, Faisal; Rehman, Abdur; Abbas, Iram; Ahmad, Nofil; Akhtar, Muhammad Usman

2014-01-01

Cysts of the jaws constitute an important pathology in the oral and maxillofacial region and are broadly classified as odontogenic and non-odontogenic. Objective of this study was to document the clinical and radiographic presentation of odontogenic cysts at a tertiary care centre. In this descriptive case-series, patients presenting with features of suspected cystic lesions of the jaws were investigated using radiographs and incisional biopsy. Subjects showing clinico- radiographic features of odontogenic cyst(s) with subsequent confirmation on histopathological examination were included. A total of 112 subjects were investigated for suspected jaw cysts and cystic diagnosis of odontogenic cysts was confirmed in 100 patients with 53 males (53%) and 47 females (47%). The age range of patients was from 12-55 years. Radicular cyst was the most commonly diagnosed odontogenic cyst (63%) followed by dentigerous cyst (22%) and odontogenickeratocyst (14%). Anterior maxilla was the most affected site (44%) followed by posterior mandible (30%). Odontogenic cysts constitute an established pathology affecting the jaws with varying frequency. This study augments the data cited from Western countries and re-emphasizes the need for early diagnosis and prompt management. It also highlights the differences in the presentation of odontogenic cysts as observed in the current series.

The longitudinal sagittal growth changes of maxilla and mandible according to quantitative cervical vertebral maturation.

PubMed

Chen, Lili; Lin, Jiuxiang; Xu, Tianmin; Long, Xiaosi

2009-04-01

To investigate the longitudinal sagittal growth changes of maxilla and mandible according to the quantitative cervical vertebral maturation (QCVM) for adolescents with normal occlusion, mixed longitudinal data were used. The samples included 87 adolescents aged from 8 to 18 y old with normal occlusion (32 males, 55 females) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year, lasting for 6 y. The longitudinal sagittal growth changes of maxilla and mandible according to QCVM were measured. There were some significant differences between maxilla and mandible according to QCVM. The sagittal growth change of maxilla showed a trend towards high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. The sagittal growth change of mandible showed a trend towards accelerating velocity-->high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. With sagittal relationship, growth magnitude was almost the same between maxilla and mandible at QCVM stage I. At stage II the growth of mandible exceeded that of maxilla and growth in mandible continued at stages III and IV, while the maxilla ceased to grow. Growth magnitude was greater and the growth duration was longer with male mandible. It is concluded that the longitudinal sagittal growth changes of maxilla and mandible on the basis of QCVM is of value in the orthodontic practice.

Unique zinc mass in mandibles separates drywood termites from other groups of termites

NASA Astrophysics Data System (ADS)

Cribb, Bronwen W.; Stewart, Aaron; Huang, Han; Truss, Rowan; Noller, Barry; Rasch, Ronald; Zalucki, Myron P.

2008-05-01

Previously, the presence of metals in arthropod mandibles has been linked with harder cuticle, and in termites, a 20% increase in hardness has been found for mandibles containing major quantities of zinc. The current study utilises electron microscopy and energy-dispersive X-ray microanalysis to assess incidence and abundance of metals in all extant subfamilies of the Isoptera. The basal clades contain no zinc and little to no manganese in the cutting edge of the mandible cuticle, suggesting that these states are ancestral for termites. However, experimentation with mandibles in vitro indicates the presence of some elements of the cuticular biochemistry necessary to enable uptake of zinc. The Termopsidae, Serritermitidae, Rhinotermitidae and Termitidae all contain minor quantities of manganese, while trace to minor quantities of zinc occur in all except the Serritermitidae. In contrast, all Kalotermitidae or drywood termites contain major levels of zinc in the mandible edge. Diet and life type are explored as links to metal profiles across the termites. The presence of harder mandibles in the drywood termites may be related to lack of access to free water with which to moisten wood. Scratch tests were applied to a set of mandibles. The coefficient of friction for Cryptotermes primus (Kalotermitidae) mandibles, when compared with species from other subfamilies, indicates that zinc-containing mandibles are likely to be more scratch resistant.

[Chronic recurrent multifocal osteomyelitis of the mandible: report of three cases].

PubMed

Paim, Luciana B; Liphaus, Bernadete Lourdes; Rocha, André C; Castellanos, Aura Ligia Z; Silva, Clovis Artur A

2003-01-01

To report three cases of chronic recurrent multifocal osteomyelitis of the mandible, an inflammatory disease affecting one or more bones with absence of isolated microorganisms in affected areas. The first case is a 13 year-old female presenting with pain and fever after dental treatment. The patient received antibiotic treatment for osteomyelitis, but developed progressive enlargement of the mandible and palmoplantar pustulosis. Bone scintigraphy showed intense and diffuse uptake in the mandible. The swelling decreased after indomethacin and hyperbaric oxygen therapy. Case 2 is a 9 year-old female patient with recurrent pain and edema of the right mandible for three years. The diagnosis of osteomyelitis was established and amoxicillin introduced. After three months, tomography showed diffuse mandible osteolysis. Indomethacin and hyperbaric oxygen therapy were introduced, however the patient presented a relapse and was treated with prednisone, rofecoxib and methotrexate. Patient 3, a 10 year-old male, had palmoplantar pustulosis and recurrent enlargement of the mandible. Tomography showed diffuse mandible osteolysis and scintigraphy revealed intense and diffuse uptake in the mandible. The patient was treated with prednisone. Rofecoxib was replaced after two relapses. Chronic recurrent multifocal osteomyelitis of the mandible is often associated with prolonged pain periods and periods of activity and remission of the inflammatory process. Its recognition is important to prevent the patient from being submitted to prolonged antibiotic therapy and unnecessary invasive procedures.

How many mandibles in a mammal? A note on terminology.

PubMed

Kierdorf, U

2011-04-01

This paper briefly reviews the usage of the term 'mandible' in the anatomical literature on mammals, with a focus on human and veterinary anatomy. In all analysed textbooks of human anatomy and physical anthropology as well as in several veterinary anatomy textbooks, the mandible is viewed as a single (unpaired) skeletal element composed of symmetrical (left and right) halves that correspond to the ossa dentalia of comparative anatomical terminology. Other authors, however, maintain that each mammal possesses a left and a right mandible, thus equating the mammalian mandible with the os dentale. The view of the presence of two mandibles per mammal is frequently found in textbooks of comparative vertebrate anatomy. Students of anatomy and workers from neighbouring disciplines need to be aware of the inconsistent use of the term mandible to avoid misunderstandings. © 2010 Blackwell Verlag GmbH.

Locally infiltrative ameloblastic fibroma in a rhesus macaque (Macaca mulatta) with characterizations of its proliferating activity and biological behavior

PubMed Central

Liu, David X.; Doyle, Lara A.; Bouljihad, Mostafa T.; Didier, Peter J.; Gilbert, Margaret H.; Wang, Xiaolei; Pahar, Bapi; Bohm, Rudolf P.; Veazey, Ronald S.; Lackner, Andrew A.

2014-01-01

An 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocular radiolucent mass with abundant osteolysis. The mass was grossly firm, fleshy, and gelatinous on the cut surface. Histologically, the mass was locally infiltrative and composed of neoplastic epithelial and mesenchymal components that stained positive for cytokeratin and vimentin, respectively. Occasional densely spherical condensations of fibroblasts resembling the cap stage of odontogenesis were present in the mesenchyma. Immunohistochemical staining with Ki-67, S-100, and CD34 indicated that both epithelial and mesenchymal components of the neoplasm had low proliferation. Alcian blue, periodic acid–Schiff, and trichrome stains showed an immature stromal component with no collagen formation. Based on the clinical, histologic, and immunophenotypic features, the tumor was identified as a locally infiltrative ameloblastic fibroma. PMID:22529141

Surgical treatment of jaw osteonecrosis in "Krokodil" drug addicted patients.

PubMed

Poghosyan, Yuri M; Hakobyan, Koryun A; Poghosyan, Anna Yu; Avetisyan, Eduard K

2014-12-01

Retrospective study of jaw osteonecrosis treatment in patients using the "Krokodil" drug from 2009 to 2013. On the territory of the former USSR countries there is widespread use of a self-produced drug called "Krokodil". Codeine containing analgesics ("Sedalgin", "Pentalgin" etc), red phosphorus (from match boxes) and other easily acquired chemical components are used for synthesis of this drug, which used intravenously. Jaw osteonecrosis develops as a complication in patients who use "Krokodil". The main feature of this disease is jawbone exposure in the oral cavity. Surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". 40 "Krokodil" drug addict patients with jaw osteonecrosis were treated. Involvement of maxilla was found in 11 patients (27.5%), mandible in 21 (52.5%), both jaws in 8 (20%) patients. 35 Lesions were found in 29 mandibles and 21 lesions in 19 maxillas. Main factors of treatment success are: cessation of "Krokodil" use in the pre- (minimum 1 month) and postoperative period and osteonecrosis area resection of a minimum of 0.5 cm beyond the visible borders of osteonecrosis towards the healthy tissues. Surgery was not delayed until sequestrum formation. In the mandible marginal or segmental resection (with or without TMJ exarticulation) was performed. After surgery recurrence of disease was seen in 8 (23%) cases in the mandible, with no cases of recurrence in the maxilla. According to our experience in this case series, surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". Cessation of drug use and jaw resection minimize the rate of recurrences in such patients. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Age estimation in 25-45 yrs. old females by physical and radiological methods

PubMed Central

Kasat, Vikrant; Karjodkar, FR; Vaz, Walter

2010-01-01

Aim: The purpose of this study was to estimate the age in living females in the later years (25 to 45 years) from general physical features and radiographic changes in the sternum and the mandible. Materials and Methods: A cross-sectional study was conducted on 64 females (32 subjects in each study and control group). All the subjects were physically examined for graying of scalp, body, pubic hair, and for wrinkling of skin of the forehead, temporal region, and below the eyes. A right lateral view of the chest was taken to determine fusion of the components of the sternum. Combined Hair Score, Combined Skin Score, and Combined Bone Fusion Score were calculated. An orthopantomogram of each patient was traced for lower jaw, mandibular canal and teeth, and D1, D2, A values were calculated. SPSS Software Version 10.1 was used for the execution of the regression command on the 32 cases of the control group, whose ages were known. Results: Combined skin score, mandible right D2, mandible right angle, and mandible left angle turned out significant in the prediction of age. Using the regression equation obtained, the age of the 32 subjects in the study group was estimated. In 9.3% of cases, the predicted ages exactly matched the actual ages. A variation of 1–4 years was seen in 75% of the cases. A variation of 6–7 years was seen in 15.6% of the cases. Conclusion: This study succeeded in most instances in predicting the ages of the study group and in arriving at a formula for age estimation between the ages of 25 and 45 years without using any invasive, costly, time - consuming, or troublesome method. PMID:21731347

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia.

PubMed

You, Tae Min; Kim, Kee-Deog; Huh, Jisun; Woo, Eun-Jung; Park, Wonse

2015-09-01

The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics. In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia

PubMed Central

You, Tae Min; Kim, Kee-Deog; Huh, Jisun; Woo, Eun-Jung

2015-01-01

Background The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics Methods In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. Results The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. Conclusions IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group. PMID:28879267

Development of a measurement system for the mechanical load of functional appliances.

PubMed

Shimazaki, Aya; Kimura, Hitoshi; Inou, Norio; Maki, Koutaro

2017-10-03

Devices called functional appliances are commonly used in orthodontics for treating maxillary protrusion. These devices mechanically force the mandible forward to apply traction force to the mandibular condyle. This promotes cartilaginous growth in the small mandible. However, no studies have clarified how much traction force is applied to the mandibular condyle. Moreover, it remains unknown as to how anatomical characteristics affect this traction force. Therefore, in this study, we developed a device for measuring the amount of force generated while individual patients wore functional appliances, and we investigated the relationship between forces with structures surrounding the mandibular condyle. We compared traction force values with cone-beam computed tomography image data in eight subjects. The functional appliance resulted in a traction force of 339-1477gf/mm, with a mean value of 196.5gf/mm for the elastic modulus of the mandible. A comparison with cone-beam computed tomography image data suggested that the mandibular traction force was affected by the mandibular condyle and shape of the articular eminence. This method can contribute to discovering efficient treatment techniques more suited to individual patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Central Telangiectatic Osteosarcoma of the Mandible in a Paediatric Patient: A Rarity

PubMed Central

Tomar, Divya; Thayath, Muhamad Nishad; Zaidi, Iram; Singh, Shikha

2016-01-01

Osteosarcoma (OS) involving the head and neck region is rare and is a diagnostic challenge due to its aggressive nature and varied presentations. Although OS constitute 40% to 60% of all bone tumours, only 10% of these occur in the head and neck region, most commonly in the maxilla and mandible. OS of the jaw bone has a different pattern and behaviour when compared to OS at other anatomic location. It occurs in a more elderly population, less aggressive and usually spreads locally rather than distant metastases. Telangiectatic Osteosarcoma (TOS) of jaws in a paediatric patient is still a very rare variant and till date only two cases have been reported in literature. Radiographic evaluation plays an important role as the clinical symptoms are not specific to the condition. Conventional radiography should always be supplemented by advanced imaging modalities for the diagnosis, which gives a three dimensional assessment and also prevents superimposition of surrounding structures. Early diagnosis and radical surgery are the keys to high survival rates. Herein, we present a third ever reported case of TOS occurring in mandible of a nine-year-old male patient. PMID:28208989

Transoral Open Reduction for Subcondylar Fractures of the Mandible Using an Angulated Screwdriver System.

PubMed

Nam, Seung Min; Kim, Yong Bae; Cha, Han Gyu; Wee, Syeo Young; Choi, Chang Yong

2015-09-01

The management of subcondylar mandibular fractures has been a matter of controversy. Although closed reduction is the most useful method, it can be difficult to achieve anatomical reduction with this technique compared with open reduction and internal fixation (ORIF). Most surgeons prefer to treat subcondylar fractures by extraoral approaches rather than intraoral approaches because extraoral approaches provide good visualization of the operative field. The retromandibular, submandibular, and perilobular approaches are commonly performed in the treatment of displaced condylar or subcondylar fractures and that the functional results of these treatments are good. However, extraoral approaches have a high rate of surgical complications such as salivary fistula formation, visible scarring, and facial nerve injury, compared with intraoral approaches. Therefore, this clinical study evaluated the clinical results of ORIF for mandibular subcondylar fractures through a transoral approach using an angulated screwdriver system without endoscopic assistance. A study was conducted between March 2011 and October 2012. Eleven patients with subcondylar fractures of the mandible were treated through a transoral approach using an angulated screwdriver. There were 10 male patients and 1 female patient aged 21 to 72 years (mean, 38 years). Nine patients had a symphyseal or parasymphyseal fracture, and 2 patients had isolated subcondylar fractures of the mandible. Eleven patients with subcondylar fractures of the mandible were treated with a transoral approach using an angulated screwdriver. The subcondylar fracture was on the left side in 6 patients and on the right in 5. All patients achieved satisfactory ranges of temporomandibular joint movement with an interincisal distance of more than 40 mm without deviation and stable individual centric occlusion. The maximum operation duration was 165 minutes, and the average duration of ORIF was 97 minutes. The association between the operation duration and the number of operations was statistically significant. Our clinical study shows that subcondylar fractures of the mandible can be treated using an angulated screwdriver system through a transoral approach and that this technique provides reliable, satisfactory, and safe clinical outcomes.

Comminuted mandibular fracture in child victim of dog bite.

PubMed

de Carvalho, Matheus Furtado; Hardtke, Luiz Augusto Paixão; de Souza, Max Filipe Cota; de Oliveira Araujo, Vasco

2012-08-01

Dog bites represent lesions commonly found in Hospital Emergency Clinic. This type of lesion may cause severe harm to patients, but it rarely affects the underlying bone structure causes facial fracture. This study aims to illustrate a rare clinical case in which a pediatric patient presented a comminuted fracture in the mandible which evolved into a unilateral avulsion of the mandibular condyle, body fractures as well as a mandibular ramus and hemiface that had been deformed, with multiple lacerations and loss of soft-tissue mass. Intermaxillary fixation was performed using the Ivy method, followed by internal rigid fixation using miniplates and screws in attempt to reconstruct the child's mandible. After 2 years of follow-up, a satisfactory esthetics and functional results could be observed. © 2011 John Wiley & Sons A/S.

[Ewing sarcoma located in the mandible: A case report].

PubMed

Hernandez, M; Droz, D; Mansuy, L; Simon, E; Chastagner, P

2015-06-01

Ewing sarcoma is the second most common primary malignant bone cancer in children and adolescents. Clinical presentation is usually dominated by local pain and a palpable mass. These symptoms justify imaging investigations: the first one, when an osseous lesion is suspected, is usually a conventional radiograph in two planes. Ewing sarcoma appears as a poorly defined osteolytic lesion that may frequently be associated with cortical erosion or laminar periosteal response ("onion skin"). However, this aspect is not pathognomonic and the definitive diagnosis is made by biopsy. Absence of pain or an unusual localization can lead to misdiagnosis. We report the case of a 7-year-old boy with Ewing sarcoma located in the mandible with a clinical picture including progressive mandibular swelling but no pain. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Odontogenic myxoma: A 63-year retrospective multicenter study of 85 cases in a Brazil population and a review of 999 cases from literature.

PubMed

Vasconcelos, Ana Carolina Uchoa; Silveira, Felipe Martins; Gomes, Ana Paula Neutzling; Tarquinio, Sandra Beatriz Chaves; Sobral, Ana Paula Veras; de Arruda, José Alcides Almeida; da Silva, Leorik Pereira; da Silveira, Marcia Maria Fonseca; Barbosa, Larissa Ferreira; Kato, Camila de Nazaré Alves de Oliveira; Jaeger, Filipe; da Silva, Tarcília Aparecida; Mesquita, Ricardo Alves

2018-01-01

Odontogenic myxoma (OM) is an uncommon neoplasm of the jaws. Considering the importance of defining the relative incidence and demographic profile of these lesions in South America, the aim of this study was to analyze the clinical and imagiological features of OM from three South American oral pathology services and to discuss these findings in light of the literature. Data regarding age, gender, anatomic site, and imagiological features from 85 cases of OM were collected. Additionally, we did a review of OM studies published in three electronic databases. Among 63 450 oral biopsies, 1178 (1.85%) were odontogenic tumors (World Health Organization - 2017), of which 85 (7.21%) met the criteria of OM. The mean age was 30.7 years (range: 10-61 years; SD: 12.22). Forty-five (52.9%) cases occurred in females and 40 (47.1%) in males (ratio: 1:1.12). Maxilla was affected in 44 cases (53%) and mandible in 39 (47%). Of the 41 informed cases (48.2%), all of them were radiolucent lesions. The literature review indicated a majority of mean ages in third decade and a predilection for females, mandible, and multilocular radiolucent lesions. The features of OM samples have strong similarity to that reported in studies from other continents. It is possible to infer that geographic variation does not help to explain some differences observed in the clinical features of OM. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Variation in shape of the lingula in the adult human mandible

PubMed Central

TULI, A.; CHOUDHRY, R.; CHOUDHRY, S.; RAHEJA, S.; AGARWAL, S.

2000-01-01

The lingulae of both sides of 165 dry adult human mandibles, 131 males and 34 females of Indian origin, were classified by their shape into 4 types: 1, triangular; 2, truncated; 3, nodular; and 4, assimilated. Triangular lingulae were found in 226 (68.5%) sides, truncated in 52 (15.8%), nodular in 36 (10.9%) and assimilated in 16 (4.8%) sides. Triangular lingulae were found bilaterally in 110, truncated in 23, nodular in 17 and assimilated in 7 mandibles. Of the remaining 8 mandibles with different appearances on the 2 sides, 6 had a combination of triangular and truncated and 2 had nodular and assimilated. The incidence of triangular and assimilated types in the male and female mandibles are almost equal. In the truncated type it was double in the male mandibles while the nodular type was a little less than double in the female mandibles. PMID:11005723

Multimethod Approach to the Early Postnatal Growth of the Mandible in Mice from a Zone of Robertsonian Polymorphism.

PubMed

Martínez-Vargas, Jessica; Muñoz-Muñoz, Francesc; López-Fuster, María José; Cubo, Jorge; Ventura, Jacint

2018-04-18

The western European house mouse (Mus musculus domesticus) shows high karyotypic diversity owing to Robertsonian translocations. Morphometric studies conducted with adult mice suggest that karyotype evolution due to these chromosomal reorganizations entails variation in the form and the patterns of morphological covariation of the mandible. However, information is much scarcer regarding the effect of these rearrangements on the growth pattern of the mouse mandible over early postnatal ontogeny. Here we compare mandible growth from the second to the eighth week of postnatal life between two ontogenetic series of mice from wild populations, with the standard karyotype and with Robertsonian translocations respectively, reared under the same conditions. A multi-method approach is used, including bone histology analyses of mandible surfaces and cross-sections, as well as geometric morphometric analyses of mandible form. The mandibles of both standard and Robertsonian mice display growth acceleration around weaning, anteroposterior direction of bone maturation, a predominance of bone deposition fields over ontogeny, and relatively greater expansion of the posterior mandible region correlated with the ontogenetic increase in mandible size. Nevertheless, differences exist between the two mouse groups regarding the timing of histological maturation of the mandible, the localization of certain bone remodeling fields, the temporospatial patterns of morphological variation, and the organization into two main modules. The dissimilarities in the process of mandible growth between the two groups of mice become more evident around sexual maturity, and could arise from alterations that Robertsonian translocations may exert on genes involved in the bone remodeling mechanism. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Calcifying epithelial odontogenic tumor, a rare presentation in children: two case reports.

PubMed

Mohanty, Susant; Mohanty, Neeta; Routray, Samapika; Misra, Satya Ranjan; Vasudevan, Vijeev

2014-01-01

Calcifying epithelial odontogenic tumor (CEOT) is a rare and benign odontogenic neoplasm that affects the jaws. It is certainly an atypical instance to find this tumor in children. Here, we present two case reports of CEOT presenting in mandible of a 12- and 13-year-old female child, respectively. CEOT have been reported to show features of malignant transformation also.

Study of mandible reconstruction using a fibula flap with application of additive manufacturing technology.

PubMed

Tsai, Ming-June; Wu, Ching-Tsai

2014-05-06

This study aimed to establish surgical guiding techniques for completing mandible lesion resection and reconstruction of the mandible defect area with fibula sections in one surgery by applying additive manufacturing technology, which can reduce the surgical duration and enhance the surgical accuracy and success rate. A computer assisted mandible reconstruction planning (CAMRP) program was used to calculate the optimal cutting length and number of fibula pieces and design the fixtures for mandible cutting, registration, and arrangement of the fibula segments. The mandible cutting and registering fixtures were then generated using an additive manufacturing system. The CAMRP calculated the optimal fibula cutting length and number of segments based on the location and length of the defective portion of the mandible. The mandible cutting jig was generated according to the boundary surface of the lesion resection on the mandible STL model. The fibular cutting fixture was based on the length of each segment, and the registered fixture was used to quickly arrange the fibula pieces into the shape of the defect area. In this study, the mandibular lesion was reconstructed using registered fibular sections in one step, and the method is very easy to perform. The application of additive manufacturing technology provided customized models and the cutting fixtures and registered fixtures, which can improve the efficiency of clinical application. This study showed that the cutting fixture helped to rapidly complete lesion resection and fibula cutting, and the registered fixture enabled arrangement of the fibula pieces and allowed completion of the mandible reconstruction in a timely manner. Our method can overcome the disadvantages of traditional surgery, which requires a long and different course of treatment and is liable to cause error. With the help of optimal cutting planning by the CAMRP and the 3D printed mandible resection jig and fibula cutting fixture, this all-in-one process of mandible reconstruction furnishes many benefits in this field by enhancing the accuracy of surgery, shortening the operation duration, reducing the surgical risk, and resulting in a better mandible appearance of the patients after surgery.

Study of mandible reconstruction using a fibula flap with application of additive manufacturing technology

PubMed Central

2014-01-01

Background This study aimed to establish surgical guiding techniques for completing mandible lesion resection and reconstruction of the mandible defect area with fibula sections in one surgery by applying additive manufacturing technology, which can reduce the surgical duration and enhance the surgical accuracy and success rate. Methods A computer assisted mandible reconstruction planning (CAMRP) program was used to calculate the optimal cutting length and number of fibula pieces and design the fixtures for mandible cutting, registration, and arrangement of the fibula segments. The mandible cutting and registering fixtures were then generated using an additive manufacturing system. The CAMRP calculated the optimal fibula cutting length and number of segments based on the location and length of the defective portion of the mandible. The mandible cutting jig was generated according to the boundary surface of the lesion resection on the mandible STL model. The fibular cutting fixture was based on the length of each segment, and the registered fixture was used to quickly arrange the fibula pieces into the shape of the defect area. In this study, the mandibular lesion was reconstructed using registered fibular sections in one step, and the method is very easy to perform. Results and conclusion The application of additive manufacturing technology provided customized models and the cutting fixtures and registered fixtures, which can improve the efficiency of clinical application. This study showed that the cutting fixture helped to rapidly complete lesion resection and fibula cutting, and the registered fixture enabled arrangement of the fibula pieces and allowed completion of the mandible reconstruction in a timely manner. Our method can overcome the disadvantages of traditional surgery, which requires a long and different course of treatment and is liable to cause error. With the help of optimal cutting planning by the CAMRP and the 3D printed mandible resection jig and fibula cutting fixture, this all-in-one process of mandible reconstruction furnishes many benefits in this field by enhancing the accuracy of surgery, shortening the operation duration, reducing the surgical risk, and resulting in a better mandible appearance of the patients after surgery. PMID:24885749

Variability of the cranial and dental phenotype in Williams syndrome.

PubMed

Axelsson, Stefan

2005-01-01

Williams syndrome (WS) is a rare congenital disorder involving the cardiovascular system, connective tissue, and the central nervous system, resulting in mild to moderate mental retardation, a specific cognitive profile, unique personality characteristics, distinctive facial features, and cardiovascular disease. The majority of individuals with a clinical diagnosis of WS have a contiguous gene deletion at chromosome 7 (7q11.23). Physical features include characteristic facial features with full prominent cheeks, wide mouth, long philtrum, small nose with depressed nasal bridge, heavy orbital ridges, medial eyebrow flare, dental abnormalities, hoarse voice, growth retardation, and cardiovascular abnormalities (most commonly supravalvular aortic stenosis and/or peripheral pulmonary artery stenosis). The cognitive profile is distinctive, consisting of strengths in auditory memory, language, and face-processing, but extreme weakness in visuospatial, numerical and problem-solving abilities. Neurological studies have identified a significantly decreased brain volume in adult individuals with WS with relatively normal development of the limbic, frontal and cerebellar structures. The aims were to analyse the neurocranium, the craniofacial region, and the dentition in a well defined Norwegian group of individuals with WS. In order to accomplish this, normative cephalometric standards for the neurocranium, including the cranial base and the sella turcica, were established for Norwegian males and females from 6 to 21 years of age, using lateral radiographic cephalograms from the Oslo University Craniofacial Growth Archive. The study material comprised radiographic lateral cephalograms, orthopantomograms and dental casts from 62 individuals with WS ranging from 4 to 44 years. The lateral cephalograms, orthopantomograms and dental casts were analysed using standard methods reported in the literature. Neurocranium: The results from the cephalometric analyses showed that the size and shape of the neurocranium in WS differed from normal controls. A flattening of the superior aspect of the parietal bone was found and the posterior prominence of the occipital bone was larger. These findings were in concordance with published neuroanatomical/neuropathological studies on WS and fit well with the reported anatomical aberrations in the WS brain, e.g. a smaller brain volume where some parts are of relatively normal size while others are decreased. The anterior and posterior cranial base was shorter in WS, but with a normal cranial base angle. The thickness of the calvarian bones, especially the frontal and occipital bones, was greater in WS than in normal controls. Sella turcica: The size of the sella turcica was somewhat smaller in WS compared with normal controls, though not significant. Aberrant types of shape of the sella turcica in WS are demonstrated. The correlation between prenatal malformation in the pituitary gland/sella turcica and the postnatal morphology of the sella turcica is discussed. The craniofacial skeleton: Two areas, in addition to the cranial base, have been identified to contribute to the characteristic facial appearance in WS; the anterior inclination of the maxilla, and the shape of the mandible. The severely deficient bony chin in combination with the high mandibular plane angle can explain earlier clinical descriptions of a retrusive mandible in WS. Frequent mouth breathing during childhood and the smaller cranial base may be associated with the characteristic craniofacial pattern. Dentition: In individuals with WS over 10 years of age 40.5 per cent had agenesis of one or more permanent teeth and 11.9 percent had agenesis of 6 teeth or more. The missing permanent teeth in the maxilla most commonly included 2nd premolars, 1st premolars, and lateral incisors. In the mandible most commonly 2nd premolars, 1st premolars, and central incisors were absent. The tooth crowns of permanent teeth were smaller, both in the mesio-distal and labio-lingual dimension. The permanent tooth crowns have several characteristic deviations from normal shape; especially incisors in both jaws were tapered or screwdriver-shaped. An evaluation of taurodontism on permanent molars was performed. However, most of the molars rated as being taurodontic had short total tooth lengths and could thus be rated taurodontic without meeting the classical definition. These studies have shown aberrations in the neurocranium including the sella turcica in WS not previously reported. In the craniofacial skeleton specific traits have been identified to contribute to the characteristic facial appearance in WS. Dental aberrations in the permanent dentition including agenesis, smaller size, and aberrant shape of teeth, are common in WS.

The accuracy of ultrashort echo time MRI sequences for medical additive manufacturing

PubMed Central

Rijkhorst, Erik-Jan; Hofman, Mark; Forouzanfar, Tymour; Wolff, Jan

2016-01-01

Objectives: Additively manufactured bone models, implants and drill guides are becoming increasingly popular amongst maxillofacial surgeons and dentists. To date, such constructs are commonly manufactured using CT technology that induces ionizing radiation. Recently, ultrashort echo time (UTE) MRI sequences have been developed that allow radiation-free imaging of facial bones. The aim of the present study was to assess the feasibility of UTE MRI sequences for medical additive manufacturing (AM). Methods: Three morphologically different dry human mandibles were scanned using a CT and MRI scanner. Additionally, optical scans of all three mandibles were made to acquire a “gold standard”. All CT and MRI scans were converted into Standard Tessellation Language (STL) models and geometrically compared with the gold standard. To quantify the accuracy of the AM process, the CT, MRI and gold-standard STL models of one of the mandibles were additively manufactured, optically scanned and compared with the original gold-standard STL model. Results: Geometric differences between all three CT-derived STL models and the gold standard were <1.0 mm. All three MRI-derived STL models generally presented deviations <1.5 mm in the symphyseal and mandibular area. The AM process introduced minor deviations of <0.5 mm. Conclusions: This study demonstrates that MRI using UTE sequences is a feasible alternative to CT in generating STL models of the mandible and would therefore be suitable for surgical planning and AM. Further in vivo studies are necessary to assess the usability of UTE MRI sequences in clinical settings. PMID:26943179

Investigation of the prevalence, clinical features, and risk factors of dentin hypersensitivity in a selected Brazilian population.

PubMed

Scaramucci, Taís; de Almeida Anfe, Taciana Emília; da Silva Ferreira, Stella; Frias, Antônio Carlos; Sobral, Maria Angela Pita

2014-01-01

To evaluate the prevalence, clinical features, and risk factors of dentin hypersensitivity (DH) in a Brazilian population. 300 patients at the Dentistry Clinic of the University of São Paulo participated in this study. The subjects completed a questionnaire regarding their personal information, the presence of DH, and some of its risk factors. Following completion of the questionnaire, a clinical examination was undertaken. To confirm the presence of DH, the subjects were evaluated with the use of a probe and cold air from a triple syringe. Statistical analysis was performed with the chi-square test and odds ratio, with the critical level p <0.05. The prevalence of DH was 46%. Females presented a higher prevalence than males (p <0.05). The left posterior region was affected by DH the most (maxilla = 41% and mandible = 36%). Cold was reported as the most common pain-inducing stimulus (88%). The pain was described as "discomfort" by 51% of the subjects with DH. Toothbrushing four times a day (p <0.05), toothbrushing with excessive force (p <0.05), bruxism (p <0.05), and gastroesophageal reflux (p <0.05) were strongly correlated with DH. The prevalence of DH was particularly high. The risk factors for DH were gender (female), toothbrushing four times a day, toothbrushing with excessive force, bruxism, and gastroesophageal reflux. DH was a common finding in this population suggesting that preventive measures considering its risk factors must be implemented in order to reduce or control the symptoms.

Generating classes of 3D virtual mandibles for AR-based medical simulation.

PubMed

Hippalgaonkar, Neha R; Sider, Alexa D; Hamza-Lup, Felix G; Santhanam, Anand P; Jaganathan, Bala; Imielinska, Celina; Rolland, Jannick P

2008-01-01

Simulation and modeling represent promising tools for several application domains from engineering to forensic science and medicine. Advances in 3D imaging technology convey paradigms such as augmented reality (AR) and mixed reality inside promising simulation tools for the training industry. Motivated by the requirement for superimposing anatomically correct 3D models on a human patient simulator (HPS) and visualizing them in an AR environment, the purpose of this research effort was to develop and validate a method for scaling a source human mandible to a target human mandible within a 2 mm root mean square (RMS) error. Results show that, given a distance between 2 same landmarks on 2 different mandibles, a relative scaling factor may be computed. Using this scaling factor, results show that a 3D virtual mandible model can be made morphometrically equivalent to a real target-specific mandible within a 1.30 mm RMS error. The virtual mandible may be further used as a reference target for registering other anatomic models, such as the lungs, on the HPS. Such registration will be made possible by physical constraints among the mandible and the spinal column in the horizontal normal rest position.

The shape of contention: adaptation, history, and contingency in ungulate mandibles.

PubMed

Raia, Pasquale; Carotenuto, Francesco; Meloro, Carlo; Piras, Paolo; Pushkina, Diana

2010-05-01

Mandibles and teeth of ungulates have been extensively studied to discern the functional significance of their design. Grazing ungulates have deeper mandibles, longer coronoid processes, flatter incisor arcades, and more hypsodont molars in comparison to browsers. If the functional significance of both mandible and teeth shapes is well-established, it remains uncertain to what extent mandible shapes are really adapted to grazing, meaning that they evolved either to serve their current biological function or just as a structural requirement to accommodate higher crowned molars. Here, we address this question by studying the contribution of phylogeny, hypsodonty, and body size to mandibular shape variation. The mandible shape appeared to be significantly influenced by hypsodonty but not by body size. Interestingly, hypsodonty-related changes influenced the tooth row in artiodactyls and perissodactyls significantly but in the opposite directions, which is ultimately related to their different digestive strategies. Yet, we obtained a strong phylogenetic effect in perissodactyls, suggesting that their mandible shape should be strongly inherited. The strength of this effect was not significant within artiodactyls (where hypsodonty explained much more variance in mandible shape). Digestive strategy is deemed to interplay with hypsodonty to produce different paths of adaptation to particular diets in ungulates.

The Conservative Treatment of Pediatric Mandible Fracture With External Nasal Splint.

PubMed

Sharifi, Reza; Hasheminasab, Mahboube

2016-09-01

The frequency of mandible fractures is relatively less in children compared with adults, but their treatment is significantly more challenging due to the concerns regarding mandible growth and the developing dentition. The authors have introduced a new way of closed reduction by using external nasal splints. In 3 patients aged between 4 and 6-year old with parasymphyseal and body fractures of mandible, fractures were reduced under general anesthesia and thermoplastic nasal splints were directly formed and trimmed to fit the lingual surface of mandible.Splints were fixed to mandible with circummandibular wiring and were retained in place for 3 weeks. All fractures healed uneventfully and the occlusion in all patients was satisfactory. All patients gained good masticatory efficiency. There was no need to use the intermaxillary fixation in any of the patients. Using thermoplastic external nasal splint for fracture stabilization in children is an easy, rapid, nonexpensive, and conservative way to treat mandible fractures in pediatric patients.

Functional constraints on tooth morphology in carnivorous mammals

PubMed Central

2012-01-01

Background The range of potential morphologies resulting from evolution is limited by complex interacting processes, ranging from development to function. Quantifying these interactions is important for understanding adaptation and convergent evolution. Using three-dimensional reconstructions of carnivoran and dasyuromorph tooth rows, we compared statistical models of the relationship between tooth row shape and the opposing tooth row, a static feature, as well as measures of mandibular motion during chewing (occlusion), which are kinetic features. This is a new approach to quantifying functional integration because we use measures of movement and displacement, such as the amount the mandible translates laterally during occlusion, as opposed to conventional morphological measures, such as mandible length and geometric landmarks. By sampling two distantly related groups of ecologically similar mammals, we study carnivorous mammals in general rather than a specific group of mammals. Results Statistical model comparisons demonstrate that the best performing models always include some measure of mandibular motion, indicating that functional and statistical models of tooth shape as purely a function of the opposing tooth row are too simple and that increased model complexity provides a better understanding of tooth form. The predictors of the best performing models always included the opposing tooth row shape and a relative linear measure of mandibular motion. Conclusions Our results provide quantitative support of long-standing hypotheses of tooth row shape as being influenced by mandibular motion in addition to the opposing tooth row. Additionally, this study illustrates the utility and necessity of including kinetic features in analyses of morphological integration. PMID:22899809

Retrospective Analysis of Ossifying Fibroma of Jaw Bones Over a Period of 10 Years with Literature Review.

PubMed

Mohanty, Sujata; Gupta, Sunita; Kumar, Priya; Sriram, K; Gulati, Ujjwal

2014-12-01

The purpose of this retrospective analysis is to document and discuss the features, treatment rendered and result of 25 histologically proven cases of ossifying fibromas of jaw bones operated by a single surgeon over a period of 10 years. The records of ossifying fibroma were obtained from the archives of Oral and Maxillofacial Surgery at Maulana Azad Institute of Dental Sciences (MAIDS) from 2001 to 2011. Only those cases were included in the study where definitive surgery was performed based on clinical, radiological & histopathological features. Twenty-five patients were analyzed with a final diagnosis of ossifying fibroma comprising of 14 males (56 %) and 11 females (44 %). The age range was 11-45 years with a mean of 24.12 years. Mandible was involved in 72 % and maxilla in 28 % cases with a predominance of mandibular posterior [19 (76 %)] cases. The study showed similar findings in regard to clinical, radiographic & histological features of ossifying fibroma as compared to other studies. It also showed that the treatment rendered in the form of eneucleation, curettage or resection of the lesion depending on its stage and extent were adequate, as no recurrence has been reported till date. Enucleation is preferred in small and well demarcated lesions. Curettage should be done in relatively large lesions with ill defined borders, not involving basal bone of mandible or cortical perforation. Resection should be reserved for aggressive and extensive cases with involvement of basal bone or perforation of cortices.

A comprehensive study on maxillofacial trauma conducted in Yamunanagar, India

PubMed Central

Bali, Rishi; Sharma, Parveen; Garg, Amandeep; Dhillon, Guneet

2013-01-01

Abstract: Background: The Department of Oral and Maxillofacial Surgery, D.A.V [C] Dental College and Hospital, Yamuna Nagar, Haryana, India conducted a study on patients with maxillofacial fractures in a time span of seven years (2003-2010). The purpose of this study was to evaluate their aetiology, incidence, patterns and different modalities employed for management. Methods: In this study, 740 patients with 1054 fractures were evaluated clinically and radiographically, based on which closed reduction and open reduction was undertaken. Review of patient records included: Age, sex, time, mechanism and etiology of injury, history of bleeding, unconsciousness and prior first aid, type of vehicle and use of preventive measures, type of fracture and treatment modalities. Results: Road traffic accidents accounted for highest number of fractures predominantly occurring in the age group of 21-30 years (38.3%)1,2. Males incurred more fractures with a male female ratio of 4.2: 1.Mandible was the most commonly fractured bone with parasymphysis being the commonest affected site.76.66% patients had associated head injury and 15.68 % had history of unconsciousness. Open reduction and internal fixation was the preferred modality for mandible whereas the mid face fractures were treated more often by closed methods. Conclusions: Injuries occurred more commonly in 20 – 40 age range with road traffic accident being the major etiological factor. Majority of the patients were driving two wheelers and most were under the effect of alcohol. Most of the injuries occurred during night and road traffic accidents (71.89%) were found to be the major etiological factor. Out of 532 road traffic accidents, 490 patients (66.2%) were on two wheelers, among whom 49(10%) were wearing helmet. In the mandible, fractures occurred most commonly in the parasymphyseal region (224, 30.2%), and out of the 314 fractures of the middle third showed, 155 (49.4%) ZMC. OPG was the most commonly advised X-ray. With regard to treatment modalities, 36.8% of all the mandibular fractures (740) were treated by closed reduction, 62.6% were treated using open reduction and 0.5% was under observation only. PMID:23594725

Histological examination and clinical evaluation of the jawbone of an adult patient with cleidocranial dysplasia: a case report

PubMed Central

Schnutenhaus, Sigmar; Luthardt, Ralph G; Rudolph, Heike; Götz, Werner

2015-01-01

Objectives: Cleidocranial dysplasia (CCD) is a rare congenital malformation syndrome, inherited autosomal-dominantly. During a course of treatment including surgical, implantological and restorative procedures, an opportunity arose to histologically examine biopsies of the maxilla and mandible of a CCD patient 47 years of age. Case report: The aim of this case report is to present the results of the histological evaluation of the alveolar bone and the surgical pretreatment for and placement of six implants each in the maxilla and the mandible. The implants were inserted in a minimally invasive procedure using 3D template guidance. Following uneventful healing of the implants, ceramically veneered bridges were cemented on individual titanium abutments. Since the patient had not received orthodontic treatment in childhood-which would have been the treatment modality of choice-this implantological and prosthodontic approach was necessary. Biopsies were taken from the maxilla and the mandible before placing the implants. Histological evaluation showed bone with strong, coarsely interconnecting trabeculae, especially in the maxilla. Both the bone and the gingiva otherwise exhibited a normal structure without pathological features or anomalies. Conclusion: The clinical parameters and histological evaluation of this one clinical case suggest that the concepts familiar from general oral implantology in terms of surgical and prosthetic procedures can be adopted for older patients with CCD. PMID:26339428

Finite Element Analysis of the Cingulata Jaw: An Ecomorphological Approach to Armadillo’s Diets

PubMed Central

Serrano-Fochs, Sílvia; De Esteban-Trivigno, Soledad; Marcé-Nogué, Jordi; Fortuny, Josep; Fariña, Richard A.

2015-01-01

Finite element analyses (FEA) were applied to assess the lower jaw biomechanics of cingulate xenarthrans: 14 species of armadillos as well as one Pleistocene pampathere (11 extant taxa and the extinct forms Vassallia, Eutatus and Macroeuphractus). The principal goal of this work is to comparatively assess the biomechanical capabilities of the mandible based on FEA and to relate the obtained stress patterns with diet preferences and variability, in extant and extinct species through an ecomorphology approach. The results of FEA showed that omnivorous species have stronger mandibles than insectivorous species. Moreover, this latter group of species showed high variability, including some similar biomechanical features of the insectivorous Tolypeutes matacus and Chlamyphorus truncatus to those of omnivorous species, in agreement with reported diets that include items other than insects. It remains unclear the reasons behind the stronger than expected lower jaw of Dasypus kappleri. On the other hand, the very strong mandible of the fossil taxon Vassallia maxima agrees well with the proposed herbivorous diet. Moreover, Eutatus seguini yielded a stress pattern similar to Vassalia in the posterior part of the lower jaw, but resembling that of the stoutly built Macroeuphractus outesi in the anterior part. The results highlight the need for more detailed studies on the natural history of extant armadillos. FEA proved a powerful tool for biomechanical studies in a comparative framework. PMID:25919313

Fibrosarcoma of the mandible following supravoltage irradiation. Report of a case.

PubMed

Moloy, P J; Kowal, K A; Siegel, W M

1989-10-01

Supravoltage irradiation is commonly thought not to be carcinogenic. Several recent studies question this concept, as does our case report. A 50-year-old woman with stage 1 squamous carcinoma of the left side of the tongue was treated in 1973 with 73 Gy of supravoltage irradiation. Twelve years later a painful, ulcerated lesion that eventually was shown to be fibrosarcoma developed in the contralateral mandible. The fibrosarcoma in this case fulfills all criteria for diagnosing radiation-induced neoplasia and demonstrates that supravoltage irradiation, like other forms of irradiation, can cause malignancy. The occasional occurrence of sarcoma should be recalled during follow-up of patients treated with supravoltage radiation. Similarly, the possibility of radiation-induced tumors should be considered in planning treatment for younger patients with tumors that can be treated equally well by surgery or irradiation.

Free body analysis, beam mechanics, and finite element modeling of the mandible of Alligator mississippiensis.

PubMed

Porro, Laura B; Holliday, Casey M; Anapol, Fred; Ontiveros, Lupita C; Ontiveros, Lolita T; Ross, Callum F

2011-08-01

The mechanical behavior of mammalian mandibles is well-studied, but a comprehensive biomechanical analysis (incorporating detailed muscle architecture, accurate material properties, and three-dimensional mechanical behavior) of an extant archosaur mandible has never been carried out. This makes it unclear how closely models of extant and extinct archosaur mandibles reflect reality and prevents comparisons of structure-function relationships in mammalian and archosaur mandibles. We tested hypotheses regarding the mechanical behavior of the mandible of Alligator mississippiensis by analyzing reaction forces and bending, shear, and torsional stress regimes in six models of varying complexity. Models included free body analysis using basic lever arm mechanics, 2D and 3D beam models, and three high-resolution finite element models of the Alligator mandible, incorporating, respectively, isotropic bone without sutures, anisotropic bone with sutures, and anisotropic bone with sutures and contact between the mandible and the pterygoid flange. Compared with the beam models, the Alligator finite element models exhibited less spatial variability in dorsoventral bending and sagittal shear stress, as well as lower peak values for these stresses, suggesting that Alligator mandibular morphology is in part designed to reduce these stresses during biting. However, the Alligator models exhibited greater variability in the distribution of mediolateral and torsional stresses than the beam models. Incorporating anisotropic bone material properties and sutures into the model reduced dorsoventral and torsional stresses within the mandible, but led to elevated mediolateral stresses. These mediolateral stresses were mitigated by the addition of a pterygoid-mandibular contact, suggesting important contributions from, and trade-offs between, material properties and external constraints in Alligator mandible design. Our results suggest that beam modeling does not accurately represent the mechanical behavior of the Alligator mandible, including important performance metrics such as magnitude and orientation of reaction forces, and mediolateral bending and torsional stress distributions. J.Morphol. 2011. © 2011 Wiley-Liss, Inc. Copyright © 2011 Wiley-Liss, Inc.

A Cohort Study of the Patterns of Third Molar Impaction in Panoramic Radiographs in Saudi Population

PubMed Central

Al-Dajani, Mahmoud; Abouonq, Anas O; Almohammadi, Turki A; Alruwaili, Mohammed K; Alswilem, Rayan O; Alzoubi, Ibrahim A

2017-01-01

Objectives: To evaluate the epidemiological patterns of third molar impaction in a cohort of patients living in the north of Saudi Arabia. Materials and Methods: A retrospective cohort study comprised of analysing 2550 Orthopantomograms (OPGs) belonging to patients who attended Aljouf University College of Dentistry between September 2013 and December 2015. OPGs were examined to determine the frequency of third molar impaction, their levels of eruption and angulations. Mixed effects logistic regression analysis was performed to calculate adjusted odds ratios. Data were weighted by age and sex based on population regional estimates. Results: 1551 patients (60.8%) with a mean age of 33.5 years-old (95%CI: 32.9 to 34) demonstrated 2650 impacted third molars. Third molars were more likely present in patients aged from 20 to 39 years-old (p<0.001); and in mandible more than maxilla (p<0.001). It showed highest vertical impaction and higher impaction rate in mandible than maxilla. Level A impaction was the most common among other levels by 1365 (53.5%). Vertical impaction was the most common pattern (1354 patients; 53.1%). Mesioangular impaction ranked second in mandible, while distoangular impaction ranked second in maxilla. There was no statistically significant difference between males and females concerning impaction frequency, depth levels and angulations. Conclusion: Impacted third molars is still a public health concern among youth and young adults. Vertically impacted mandibular third molars with their occlusal plane at the same level as the occlusal plane of adjacent tooth is the most prevalent pattern of third molar impaction in the northern region of Saudi Arabia. PMID:29387281

Evaluation of the Position of Mental Foramen for Clinical and Forensic Significance in terms of Gender in Dentate Subjects by Digital Panoramic Radiographs.

PubMed

Thakare, Shweta; Mhapuskar, Amit; Hiremutt, Darshan; Giroh, Versha R; Kalyanpur, Kedarnath; Alpana, K R

2016-09-01

Evaluation of the position of mental foramen aids in forensic, surgical, endodontic, as well as diagnostic procedures. Thus, in view of this, the present study was conducted among the population of Pune, a central part of India, to determine the most regular location of the mental foramen and to estimate difference in position of mental foramen based on gender. The present retrospective study was commenced on 200 digital panoramic radiographs of dentate patients. The location of the representation of the mental foramen was traced. Measurements for evaluating distance of superior and inferior borders of the foramen in relation to the lower border of the mandible were made using the reference lines drawn from anatomical landmarks. The data so obtained were statistically analyzed using chi-square test. The most common position of mental foramen among Pune population in horizontal plane in both male and female patients was in line with second premolar followed by position in between first and second premolar, whereas in the vertical plane, most common position was at or in line with apex of second premolar followed by in between apex of first and second premolar. The variation in length of superior and inferior border of the foramen in relation to lower border of the mandible with respect to gender was found to be significant, with p-value <0.05. There was no difference in position of mental foramen in horizontal and vertical planes based on gender. The stability of location of mental foramen and significant difference in length of superior and inferior border of the foramen in relation to lower border of the mandible with respect to gender offer its application in forensic identification of gender.

A new species of Deltaspis Audinet-Serville (Coleoptera: Cerambycidae: Cerambycinae) from Mexico.

PubMed

Eya, Bryan K

2017-03-27

As currently defined, the genus Deltaspis Audinet-Serville, 1834, contains 16 species ranging in distribution from the southwestern United States to eastern Mexico. However, the generic distinction between Deltaspis and its closely allied genera, such as Crossidius LeConte, 1851 and Muscidora Thomson, 1864, is in need of clarification. According to Audinet-Serville, Deltaspis is so named due to its distinctive triangular scutellum (i.e., Δετα, delta, ασπιζ écusson), which is actually a commonly shared character of all these genera. Members of the tribe Trachyderini Dupont (1836), which includes the above genera, also have mandibles with an emarginate-truncate apex with the edge chisel-like or bifid. This modification of mouthpart appears to be for consumption of pollen and/or petals from composite flowers visited by the adult beetles (Krenn et al., 2005; Beierl & Barchet-Beierl, 1999). Other genera from this tribe with this modification of mandibles from North America, and mostly from Mexico, include: Chemsakiella Monné, 2006, Giesbertia Chemsak & Linsley, 1984, Hoegea Bates, 1885, Neocrossidius Chemsak, 1959, Paroxoplus Chemsak, 1959, Plionoma Casey, 1912, Schizax LeConte, 1873, and Tylosis LeConte, 1850. The remainder of Trachyderini genera have unmodified or simple mandibles with apex acute.

Management of pediatric mandible fractures.

PubMed

Goth, Stephen; Sawatari, Yoh; Peleg, Michael

2012-01-01

The pediatric mandible fracture is a rare occurrence when compared with the number of mandible fractures that occur within the adult population. Although the clinician who manages facial fractures may never encounter a pediatric mandible fracture, it is a unique injury that warrants a comprehensive discussion. Because of the unique anatomy, dentition, and growth of the pediatric patient, the management of a pediatric mandible fracture requires true diligence with a variance in treatment ranging from soft diet to open reduction and internal fixation. In addition to the variability in treatment, any trauma to the face of a child requires additional management factors including child abuse issues and long-term sequelae involving skeletal growth, which may affect facial symmetry and occlusion. The following is a review of the incidence, relevant anatomy, clinical and radiographic examination, and treatment modalities for specific fracture types of the pediatric mandible based on the clinical experience at the University of Miami/Jackson Memorial Hospital Oral and Maxillofacial Surgery program. In addition, a review of the literature regarding the management of the pediatric mandible fracture was performed to offer a more comprehensive overview of this unique subset of facial fractures.

Biomechanical loading test on reconstructed mandibles with fibular, iliac crest or scapula graft: a comparative study.

PubMed

Grohmann, Isabella; Raith, Stefan; Mücke, Thomas; Stimmer, Herbert; Rohleder, Nils; Kesting, Marco R; Hölzle, Frank; Steiner, Timm

2015-10-01

Advantages and disadavantages of the three most commonly-used bone grafts for mandibular reconstruction are widely known, but biomechanical experimental studies are rare. We have done loading tests on cadaveric mandibles reconstructed with fibular, iliac crest, and scapular grafts using 3 different osteosynthesis systems to detect and compare their primary stability. Loading tests were done on mandibles with grafts from the fibula and iliac crest and published previously. A 4.5cm paramedian L-type defect was reconstructed with scapula using 2 monocortical non-locking plates, 2 monocortical locking plates, or a single bicortical locking plate/fracture gap in 18 human cadaveric mandibles. These were loaded on to the "Mandibulator" test bench and the movement of fragments in 3 dimensions was assessed and quantified by a PONTOS® optical measurement system. Comparison of the osteosynthesis groups showed that the miniplate was significantly superior to the 6-hole TriLock® plate for both fibular and iliac crest grafts. The fibular graft gave greater stability than the iliac crest and scapular grafts for all 3 osteosynthesis systems. All bony specimens offered sufficient resistance to mechanical stress within the recognised range of biting forces after mandibular reconstruction, independently of the choice of bone graft and osteosynthesis system used. Anatomical and surgical advantages need to be taken into account when choosing a graft. Stability can be maximised with a fibular graft, and further optimised by enlarging the binding area by using the "double barrel" method. Computer simulated experiments could segregate factors that biased results, such as morphological differences among cadavers. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Clinical experiences with laser-welded titanium frameworks supported by implants in the edentulous mandible: a 5-year follow-up study.

PubMed

Ortorp, A; Linden, B; Jemt, T

1999-01-01

The purpose of this study was to report the 5-year clinical performance of implant-supported prostheses with laser-welded titanium frameworks and to compare their performance with that of prostheses provided with conventional cast frameworks. On a routine basis, a consecutive group of 824 edentulous patients were provided with fixed prostheses supported by implants in the edentulous mandible. In addition to conventional gold-alloy castings, patients were at random provided with 2 kinds of laser-welded titanium frameworks. In all, 155 patients were included in the 2 titanium framework groups. A control group of 53 randomly selected patients with conventional gold-alloy castings was used for comparison. Clinical and radiographic 5-year data was collected for the 3 groups. All followed patients still had fixed prostheses in the mandible after 5 years. The overall cumulative success rates were 95.9% and 99.7% for titanium-framework prostheses and implants, respectively. The corresponding success rates for the control group were 100% and 99.6%, respectively. Bone loss was 0.5 mm on average during the 5-year follow-up period. The most common complications for titanium frameworks were resin or tooth fractures, gingival inflammation, and fractures of the metal frames (10%). One of the cast frameworks fractured and was resoldered. Loose and fractured implant screw components were few (< 1%). Even though the cast frameworks had a higher success rate, the overall titanium framework treatment result was well in accordance with the result of the control group. The test groups performed better after clinicians had gained some experience with the technique, and laser-welded titanium frameworks seem to be a viable alternative to conventional castings in the edentulous mandible.

Outcome and prognostic factors for osteosarcoma of the maxilla, mandible, or calvarium in dogs: 183 cases (1986-2012).

PubMed

Selmic, Laura E; Lafferty, Mary H; Kamstock, Debra A; Garner, Alana; Ehrhart, Nicole P; Worley, Deanna R; Withrow, Stephen J; Lana, Susan E

2014-10-15

To describe the biological behavior, clinical outcome, and prognostic factors of osteosarcoma of the maxilla, mandible, or calvarium in dogs. Retrospective case series. 183 client-owned dogs with osteosarcoma of the maxilla, mandible, or calvarium. Medical records for dogs treated for osteosarcoma of the maxilla, mandible, or calvarium from 1986 through 2012 were reviewed. Dogs with a histopathologic diagnosis of osteosarcoma and treated for a primary tumor arising from these bones of the head were included. Mean age was 9.3 years, and body weight was 31.8 kg (70.0 lb). Most dogs (124/183 [67.8%]) were purebred, and the most common primary tumor site was the maxilla (80 [43.7%]). Treatments included palliative medical treatment only (11/183 [6.0%]), coarsely fractionated radiation therapy (RT; 12 [6.6%]), fractionated or stereotactic RT (18 [9.8%]), surgery (135 [73.8%]), and both surgery and fractionated RT (7 [3.8%]). Eighty-three (45.4%) dogs received adjuvant chemotherapy. Local recurrence or progression occurred in 80 of 156 (51.3%) dogs, and 60 of 156 (38.5%) dogs developed distant metastases. Median survival time for all dogs was 239 days. Dogs that underwent surgery had a median survival time of 329 days. Histologically tumor-free surgical margins were associated with significantly decreased hazards of progression or recurrence (hazard ratio [HR], 0.4) and death (HR, 0.5). Dogs with osteosarcoma of the calvarium had a significantly greater hazard of local recurrence or progression (HR, 2.0). In this study, tumor excision in dogs with histologically tumor-free margins resulted in better local control and longer survival time than did other treatment types.

Dynamic simulation and preliminary finite element analysis of gunshot wounds to the human mandible.

PubMed

Tang, Zhen; Tu, Wenbing; Zhang, Gang; Chen, Yubin; Lei, Tao; Tan, Yinghui

2012-05-01

Due to the complications arising from gunshot wounds to the maxillofacial region, traditional models of gunshot wounds cannot meet our research needs. In this study, we established a finite element model and conducted preliminary simulation and analysis to determine the injury mechanism and degree of damage for gunshot wounds to the human mandible. Based on a previously developed modelling method that used animal experiments and internal parameters, digital computed tomography data for the human mandible were used to establish a three-dimensional finite element model of the human mandible. The mechanism by which a gunshot injures the mandible was dynamically simulated under different shot conditions. First, the residual velocities of the shootings using different projectiles at varying entry angles and impact velocities were calculated. Second, the energy losses of the projectiles and the rates of energy loss after exiting the mandible were calculated. Finally, the data were compared and analysed. The dynamic processes involved in gunshot wounds to the human mandible were successfully simulated using two projectiles, three impact velocities, and three entry angles. The stress distributions in different parts of mandible after injury were also simulated. Based on the computation and analysis of the modelling data, we found that the injury severity of the mandible and the injury efficiency of the projectiles differ under different injury conditions. The finite element model has many advantages for the analysis of ballistic wounds, and is expected to become an improved model for studying maxillofacial gunshot wounds. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biology of Scolytus piceae (Coleoptera: Curculionidae: Scolytinae) in Northern Idaho and Notes on Comparative Anatomical Features of the Larva.

PubMed

Furniss, Malcolm M; Kegley, Sandra J

2017-06-01

The forests of the northern Rocky Mountains are hosts of nine species of Nearctic conifer-infesting bark beetles of the genus Scolytus Geoffroy. One of these, Scolytus piceae Swaine (Coleoptera: Curculionidae), infests spruces across the continent including Picea engelmannii Parry (Pinaceae) in Idaho. Mature larvae overwintered before transforming to adults, which infested new hosts in early June. Scolytus piceae most commonly infested shaded out lower branches of mature live spruce. In sporadic wind-felled spruce, the beetle infested the terminal portion of branches throughout the crown, whereas another Scolytinae, Polygraphus rufipennis (Kirby), infested the thicker bark basal portion of the same branches. This niche separation resulted from difference in time of their dispersal flight and ability of S. piceae to colonize thin bark by engraving the underlying sapwood. Population recruitment of S. piceae was low in shaded out lower branches, in balance with this limited host resource. Features of the head of S. piceae larvae differed from that reported in literature, including the mandible dentition, antennal field, and pattern of setae on the postlabium. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Intraosseous Leiomyoma of the Jaw in an Adolescent.

PubMed

Valls-Ontañón, Adaia; Pozuelo-Arquimbau, Laura; Mateu-Esquerda, Gemma; Arranz-Obispo, Carlos; Cuscó-Albors, Sílvia; Melero-Luque, Mireia; Morla, Arnaud; Marí-Roig, Antoni

2017-05-15

Leiomyoma is a benign tumor of the smooth muscle that rarely occurs in the mouth as an intraosseous lesion. The purposes of this paper are to: (1) present a case of an intraosseous solid leiomyoma of the mandible in a 13-year-old child, who presented with a well-defined unilocular radiolucency in the right mandible incidentally discovered during a routine dental radiographic examination; and (2) conduct a review of the literature to describe clinicopathological features and management of intraosseous jaw leiomyoma (IJL). A total of 17 articles describing 18 cases of IJL satisfied the selection criteria; including the present patient, to date a total of 19 cases of IJL have been reported. IJL occurs mainly in young patients (36.8 percent), more often in boys (1:5:1 male-to-female ratio), and reaches a larger size in children than in adults. The treatment of choice for IJL is surgical excision, which should be as minimally invasive as possible, especially in children.

Cemento-ossifying fibroma of the jaw

PubMed Central

Katti, Girish; Khan, Mohammed Munnawarulla; Chaubey, Shashi Shanker; Amena, Mehroz

2016-01-01

Cemento-ossifying fibroma is a benign growth, considered to originate from the periodontal ligament. It is often encapsulated and predominantly located in the mandible, and presents as a slow-growing lesion, but may cause deformity if left untreated. The definitive diagnosis of these lesions requires integration of its clinical, radiological and histological features. We present a case of cemento-ossifying fibroma in relation to the lower left one-third of the face, and its management. PMID:27174452

Maxillofacial trauma of pediatric patients in Malaysia: a retrospective study from 1999 to 2001 in three hospitals.

PubMed

Rahman, Roslan Abdul; Ramli, Roszalina; Rahman, Normastura Abdul; Hussaini, Haizal Mohd; Idrus, Sharifah Munirah Ai; Hamid, Abdul Latif Abdul

2007-06-01

Maxillofacial trauma in children is not common worldwide. Domestic injuries are frequently seen in younger children while older children are mostly involved in motor vehicle accidents (MVA). The objective of this study was to analyze the pattern of maxillofacial injuries in pediatric patients referred to three government main hospitals in different areas of West Malaysia. Patients' records of three selected hospitals in Malaysia (National University of Malaysia Hospital, Kajang Hospital and Seremban Hospital) from January 1999 to December 2001 were reviewed. Data associated with demographics, etiology of injury in relation to age group, type of injuries whether soft tissues of hard tissue in relation to age group and treatment modalities were collected. A total of 521 pediatric patients' records were reviewed. Malays made up the majority of patients with maxillofacial injuries in the three hospitals. Males outnumbered females in all the three hospitals. Injuries commonly occur in the 11-16 years old. MVA was the most common etiology followed by fall and assault. Soft tissue injuries were the most common type of injuries in all the hospitals. In relation to fractures, mandible was the most common bone to fracture with condyle being the most common site. Orbital fracture was the most common fracture in the midfacial area. Most of the fractures were managed conservatively especially in the younger age groups. Open reduction with or without internal fixation was more frequently carried out in the 11-16 years old group. Children exhibit different pattern of clinical features depending on the etiology and stage of their bone maturation. A dedicated team, who is competent in trauma and aware of the unique anatomy, physical and psychological characteristics of children, should manage pediatric patient with trauma.

Comparative biomechanical evaluation of mono-cortical osteosynthesis systems for condylar fractures using photoelastic stress analysis.

PubMed

Christopoulos, Panos; Stathopoulos, Panagiotis; Alexandridis, Constantinos; Shetty, Vivek; Caputo, Angelo

2012-10-01

Fractures of the condyle account for 20-30% of all mandibular fractures, and are therefore one of the most common facial injuries. Precise evaluation of the mechanical stresses that develop in a fractured mandible is essential, particularly for the testing of systems currently used for stabilisation of the condylar fragment. Photoelastic stress analysis can be used to visualise alterations in the strain that is induced in the mandible by a fracture, and in the osteosynthesis materials used to stabilise it. This method, used on currently used osteosynthesis materials, showed that stabilisation of a subcondylar fracture with a single miniplate does not provide enough stability, whereas the use of two miniplates - properly positioned - offers sufficient stability in all loading conditions. A microplate may be used as a tension-resisting plate with equally good results. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Therapeutic Challenge in a Severely Atrophic Mandible

PubMed Central

Janev, Edvard; Janeva, Nadica; Peeva–Petreska, Marija; Mitic, Kristina

2018-01-01

BACKGROUND: After tooth loss, however, severely atrophic residual alveolar ridges are fairly common, especially in patients who have been edentulous for a long period. Anterior area of the mandible is areas where clinicians have greater anatomical limitations. Reduced alveolar bone height very often represents a contraindication to implant therapy, unless a procedure such as a ridge augmentation is performed. CASE REPORT: This study aims to present two separate cases in highly selected edentulous anterior mandibular sites, where one stage, mini implants were used to support total prostheses. Small diameter implants have been used for retention of complete removable mandibular overdentures. This is an excellent option for those who suffer from the inconvenience and embarrassment of loose lower dentures and are tired of having to use sticky pastes and creams to make their dentures stay in place. CONCLUSION: Small diameter implants, when used multiples may offer adequate support for a removable prosthesis and overcome this problem. PMID:29610621

Clinicopathological study of 252 jaw bone periapical lesions from a private pathology laboratory.

PubMed

Lin, Hung-Pin; Chen, Hsin-Ming; Yu, Chuan-Hang; Kuo, Ru-Cheng; Kuo, Ying-Shiung; Wang, Yi-Ping

2010-11-01

Periapical lesions are common sequelae of pulp diseases. This retrospective study evaluated the clinical and histopathological features of periapical lesions sent to a private pathology laboratory by dentists in private clinics. Two hundred and fifty-two consecutive cases of periapical lesions were collected from September 2005 to October 2009. Clinical data and histopathological features of these periapical lesions were reviewed and analyzed. The 252 periapical lesions consisted of 128 periapical granulomas, 117 periapical cysts, and seven periapical scars. These 252 lesions were taken from 252 patients (92 men and 160 women; mean age = 43.6 years; range, 9-81 years). Of the 252 periapical lesions, 186 were found in the maxilla and 66 in the mandible. The most common site for periapical lesions was the maxillary anterior region (134 cases, including 73 granulomas, 54 cysts and 7 scars), and the most frequently involved tooth was the maxillary lateral incisor (64 cases, including 29 granulomas, 31 cysts and 4 scars). Of the 117 periapical cysts, 116 were lined by stratified squamous epithelium and one by mucoepidermoid epithelium. Hyaline bodies were discovered in the lining epithelium of four periapical cysts. Odontogenic epithelial rest, cholesterol cleft, foamy histiocytes, hemosiderin-laden macrophages, dystrophic calcification, foreign bodies, and bacterial clumps were found in five, three, nine, two, 28, 10 and one periapical granulomas, respectively, as well as in six, 11, eight, seven, 19, nine and eight periapical cysts, respectively. Granulomas and cysts were the two most common periapical lesions. Periapical lesions occurred more frequently in female patients and in those in their fourth to fifth decades. The most commonly affected site for periapical lesions was the maxillary anterior region, and the most frequently involved tooth was the maxillary lateral incisor. Copyright © 2010 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

Analysis of Prevalence and Clinical Features of Ameloblastoma and its Histopathological Subtypes in Southeast Myanmar and Lower Northern Thailand Populations: A 13-Year Retrospective Study

PubMed Central

2017-01-01

Introduction Prevalence of ameloblastomas has been established worldwide but collective data of ameloblastoma in Southeast Asian countries has not been well analyzed. Aim Aim of this study was to report analysis and comparison of the prevalence and demographic data of clinical features of ameloblastoma and its histopathological variants in Southeast Myanmar and lower Northern Thailand populations. Materials and Methods A retrospective study on ameloblastoma was performed based on the availability of oral biopsy specimens in Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand, between January 2002 and August 2015. The collected data were subjected to descriptive statistical analyses with the SPSS version 17.0 statistical software package (SPSS Inc., Chicago, USA). Pearson’s chi square (χ2) test and t-test were employed. The critical level of significance was set at p<0.05. Results Total of 616 cases were reviewed, 30 cases (5%) were diagnosed as ameloblastoma with male:female ratio of 1.14:1. The mean age of the patients was 31.3±15.6 years. The predominance anatomical distribution was observed in the mandible (86.7%). Posterior body-ramus-angle region was the most common site. Almost all cases were asyptomatic and most common clinical manifestation was swelling of affected region. Multilocular radiolucency was observed in 70% of cases, whereas 30% were unilocular. Three subtypes of ameloblastomas were diagnosed: unicystic ameloblastoma (20%), conventional solid/multicystic ameloblastoma (70%), and desmoplastic ameloblastoma (10%). The most common histologic pattern was the plexiform type (57.2%) followed by follicular type (23.8%). Conclusion Prevalence of ameloblastoma in Southeast Myanmar and lower Northern Thailand populations correspond with data from other geographic areas of Thailand and other Asian countries. However, some demographic and histopathological profiles are different, with plexiform ameloblastoma being the most common subtype in this study. PMID:28274056

Clinical characteristics and presentation of ameloblastomas: an 8-year retrospective study of 240 cases in Eastern Nigeria.

PubMed

Chukwuneke, F N; Anyanechi, C E; Akpeh, J O; Chukwuka, A; Ekwueme, O C

2016-05-01

Our aim was to summarise the clinical characteristics and presentation of ameloblastomas in eastern Nigeria. We organised a retrospective study of 240 patients who presented with ameloblastomas to the Oral and Maxillofacial Surgery units of five specialist hospitals in the eastern states of Nigeria over an eight-year period (2004-2011). We analysed the casenotes, and categorised the cases by site of tumour, age, sex, and time of presentation. There were 117 men (49%) (mean (SD) age 43 (6.2) years) and 123 women (51%) (mean (SD) age 32 (4.7) years), a male:female ratio of 1:1.1. The largest age group was 20-39 years (n=102, 43%), and the most common site was the anterior mandible (n=140, 58%). Most of the patients presented late. Our results show that the most common site of ameloblastomas in Eastern Nigeria is the anterior mandible and that women are affected more than men, which is at variance with the results of most other studies. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Unsuccessful Treatment of Atrophic Mandible Fracture by Use of Improper Materials.

PubMed

de Moraes Ferreira, Ana Carulina Rezende; Garcia Junior, Idelmo Rangel; Silva, Adalberto Novaes; de Carvalho Reis, Erik Neiva Ribeiro; Pires, Willian Ricardo; Bonardi, João Paulo; Borba, Alexandre Meireles

2016-06-01

Fractures of atrophic mandibles are present on the day by day of buccomaxillofacial surgeons. Mandible atrophy occurs due to tooth loss, which over time induces bone resorption leading to a fragile and susceptible to fracture structure. This paper reports the case of a patient victim of face trauma resulting in atrophic mandible fracture with treatment failure through the use of shared load miniplate. Therefore, a new treatment was performed with miniplate of system 2.4 along with bone graft. After 6 months, the patient was rehabilitated with implant-supported prosthesis installation. It is concluded that for successful treatment of atrophic mandible fractures, the use of rigid plates is necessary, allowing an excellent rehabilitation of the stomatognathic system.

Superolateral dislocation of the intact mandibular condyle associated with panfacial fracture: a case report and literature review.

PubMed

Amaral, Márcio Bruno; Bueno, Sebastião Cristian; Silva, Alice Araújo Ferreira; Mesquita, Ricardo Alves

2011-06-01

Superolateral dislocation of the intact mandibular condyle (SDIMC) is rare. This case report focuses on a 15-year-old teenager who was involved in a motor vehicle accident as well a literature review regarding the SDIMC. Clinical examination demonstrated a diffuse edema in the midfacial area and a left lateral deflection of the mandible, including an open bite and a crepitation in the symphyseal region. Three-dimensional computed tomography scans were taken, which presented a superolateral dislocation of the left mandibular condyle as well as panfacial fracture. The patient was set in intermaxillary fixation for 2 weeks and underwent subsequent active jaw physiotherapy, the evaluation of which presented satisfactory results. This case study also presents a literature review, which demonstrated 21 well-documented cases of SDIMC. The patients' mean age was of 29 years. The male gender proved to be more prevalent, with road traffic collisions representing the most common form of accident. Type II, with unilateral dislocation, proved to be the most common. The mean reduction time was 7 days. The open methods were the most commonly used reduction methods. Mandible fracture was associated with dislocation in 82% of the cases, with other facial fractures appearing in only 23% of the cases. Patient follow up presented satisfactory results in 59% of the cases. © 2011 John Wiley & Sons A/S.

A novel approach for planning orthognathic surgery: the integration of dental casts into three-dimensional printed mandibular models.

PubMed

Ayoub, A F; Rehab, M; O'Neil, M; Khambay, B; Ju, X; Barbenel, J; Naudi, K

2014-04-01

A method of producing a composite model consisting of a three-dimensional printed mandible bearing plaster teeth is presented. Printed models were obtained from cone beam computed tomograms (CBCT) of dry human mandibles. The plaster casts of the teeth were obtained from impressions of the teeth of the dry mandibles. The distorted teeth of the printed models were removed and replaced by the plaster casts of the teeth using a simple transfer jig. The accuracy of the composite models obtained from six mandibles was assessed from laser scans. The scans of the dry mandibles and the composite models were superimposed and the magnitude of the discrepancies at six points on the dentition and six on the mandible were obtained. It was concluded that the errors of the method were small enough to be clinically significant. The use of the composite models is illustrated in two clinical cases. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Evaluation of stress changes in the mandible with a fixed functional appliance: a finite element study.

PubMed

Chaudhry, Anshul; Sidhu, Maninder S; Chaudhary, Girish; Grover, Seema; Chaudhry, Nimisha; Kaushik, Ashutosh

2015-02-01

The aim of this study was to evaluate the effects of a fixed functional appliance (Forsus Fatigue Resistant Device; 3M Unitek, Monrovia, Calif) on the mandible with 3-dimensional finite element stress analysis. A 3-dimensional finite element model of the mandible was constructed from the images generated by cone-beam computed tomography of a patient undergoing fixed orthodontic treatment. The changes were studied with the finite element method, in the form of highest von Mises stress and maximum principal stress regions. More areas of stress were seen in the model of the mandible with the Forsus compared with the model of the mandible in the resting stage. This fixed functional appliance studied by finite element model analysis caused increases in the maximum principal stress and the von Mises stress in both the cortical bone and the condylar region of the mandible by more than 2 times. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Cemento-ossifying fibroma of the jaw.

PubMed

Katti, Girish; Khan, Mohammed Munnawarulla; Chaubey, Shashi Shanker; Amena, Mehroz

2016-05-12

Cemento-ossifying fibroma is a benign growth, considered to originate from the periodontal ligament. It is often encapsulated and predominantly located in the mandible, and presents as a slow-growing lesion, but may cause deformity if left untreated. The definitive diagnosis of these lesions requires integration of its clinical, radiological and histological features. We present a case of cemento-ossifying fibroma in relation to the lower left one-third of the face, and its management. 2016 BMJ Publishing Group Ltd.

Management of gunshot wounds to the mandible.

PubMed

Peleg, Michael; Sawatari, Yoh

2010-07-01

The gunshot wound to the mandible is a unique traumatic injury. The resultant injury from the gunshot wound is diverse because of the variability of the projectile, motion, velocity, and tissue characteristics. When a high-velocity projectile strikes the mandible, often times the wound will consist of a severely comminuted mandible surrounded by nonvital soft tissues and the implantation of multiple foreign bodies. This represents a challenge for the treating surgeon. The anatomy and function of the mandible make it such that the care of the gunshot wound requires a combination of trauma and reconstructive surgeries. There are varying techniques advocated for the management of gunshot wound to the face. However, for the comminuted mandible fracture sustained from a gunshot wound, an approach involving the fabrication of an occlusal splint, intermaxillary fixation, aggressive debridement of hard and soft tissues, and immediate reconstruction with a titanium plate is a comprehensive approach that can restore the appropriate function and contour of the patient. At the Division of Oral and Maxillofacial Surgery, University of Miami, this approach to the comminuted mandible fracture secondary to the gunshot wound has led to the effective management of this specific subset of injury. The complication rate is comparable with the current literature and provides an advantage as a 1-stage management to restore appropriate function and cosmesis to the patient.

Finite Element Simulation and Additive Manufacturing of Stiffness-Matched NiTi Fixation Hardware for Mandibular Reconstruction Surgery

PubMed Central

Jahadakbar, Ahmadreza; Shayesteh Moghaddam, Narges; Amerinatanzi, Amirhesam; Dean, David; Karaca, Haluk E.; Elahinia, Mohammad

2016-01-01

Process parameters and post-processing heat treatment techniques have been developed to produce both shape memory and superelastic NiTi using Additive Manufacturing. By introducing engineered porosity, the stiffness of NiTi can be tuned to the level closely matching cortical bone. Using additively manufactured porous superelastic NiTi, we have proposed the use of patient-specific, stiffness-matched fixation hardware, for mandible skeletal reconstructive surgery. Currently, Ti-6Al-4V is the most commonly used material for skeletal fixation devices. Although this material offers more than sufficient strength for immobilization during the bone healing process, the high stiffness of Ti-6Al-4V implants can cause stress shielding. In this paper, we present a study of mandibular reconstruction that uses a dry cadaver mandible to validate our geometric and biomechanical design and fabrication (i.e., 3D printing) of NiTi skeletal fixation hardware. Based on the reference-dried mandible, we have developed a Finite Element model to evaluate the performance of the proposed fixation. Our results show a closer-to-normal stress distribution and an enhanced contact pressure at the bone graft interface than would be in the case with Ti-6Al-4V off-the-shelf fixation hardware. The porous fixation plates used in this study were fabricated by selective laser melting. PMID:28952598

Finite Element Simulation and Additive Manufacturing of Stiffness-Matched NiTi Fixation Hardware for Mandibular Reconstruction Surgery.

PubMed

Jahadakbar, Ahmadreza; Shayesteh Moghaddam, Narges; Amerinatanzi, Amirhesam; Dean, David; Karaca, Haluk E; Elahinia, Mohammad

2016-12-19

Process parameters and post-processing heat treatment techniques have been developed to produce both shape memory and superelastic NiTi using Additive Manufacturing. By introducing engineered porosity, the stiffness of NiTi can be tuned to the level closely matching cortical bone. Using additively manufactured porous superelastic NiTi, we have proposed the use of patient-specific, stiffness-matched fixation hardware, for mandible skeletal reconstructive surgery. Currently, Ti-6Al-4V is the most commonly used material for skeletal fixation devices. Although this material offers more than sufficient strength for immobilization during the bone healing process, the high stiffness of Ti-6Al-4V implants can cause stress shielding. In this paper, we present a study of mandibular reconstruction that uses a dry cadaver mandible to validate our geometric and biomechanical design and fabrication (i.e., 3D printing) of NiTi skeletal fixation hardware. Based on the reference-dried mandible, we have developed a Finite Element model to evaluate the performance of the proposed fixation. Our results show a closer-to-normal stress distribution and an enhanced contact pressure at the bone graft interface than would be in the case with Ti-6Al-4V off-the-shelf fixation hardware. The porous fixation plates used in this study were fabricated by selective laser melting.

Trauma of facial skeleton in children: An indian perspective.

PubMed

Karim, Tanweer; Khan, Arshad Hafeez; Ahmed, Syed Saeed

2010-06-01

Both children and adults are subject to similar types of injuries but fractures of facial bones in children are relatively uncommon. The aim of this study was to evaluate the epidemiology of facial bone fractures among children of <12 years, their management and outcome in an Indian city. This retrospective study included children of <12 years of age with facial bone fractures admitted over a span of 3 years. In order to compare our results we reviewed the existing literature related to pediatric facial bone fractures. A total of 45 children were admitted for facial bone fractures. Forty (89%) of them were above 5 years of age and male to female ratio was 2:1. About 53.33% of these injuries were because of fall from height. Mandible fracture was the most common facial bone fracture among admitted patients. Symphysis and para-symphysis was the commonest site of mandibular fractures, seen in 49% cases. Majority of these fractures were managed by Inter-maxillary fixation and inter-osseous wiring. Mini-plates were used for widely displaced compound fractures. For un-displaced fractures observation alone was sufficient. Mandible is the commonest facial bone fracture in children, more often caused by accidental fall from height. The high osteogenic potential of pediatric mandible allows non-surgical management to be successful in an increased proportion of younger patients.

A Volumetric Assessment Using Computed Tomography of Canine and First Molar Roots in Dogs of Varying Weight.

PubMed

Scherer, Ellen; Snyder, Christopher J; Malberg, Jessica; Rigby, Brittney; Hetzel, Scott; Waller, Ken

2018-06-01

Mandibular volume and tooth root volumes were shown to increase at different rates at locations containing the roots of the canine (C) and mesial and distal roots of the first molar (M1). Thirty-six dogs were included in this study. Data were generated using computed tomography at locations of the mandible involving the roots of the C and M1 teeth. Software was used to trace the external surface of the mandible, calculating the volume of the mandible at each location. Similar techniques were used to trace and calculate the volume of the C and M1 roots. Mandible volume, tooth root volume, and root percentage of mandible volume were analyzed and compared using the slopes of the best fit line. At the M1 mesial and distal roots, mandible volume ( P < .001) and root volume ( P < .001) were both noted to increase, with increasing weight at different rates. The rate of change in the root percentage by weight of M1 roots was not different ( P = .214). Each location demonstrated a different increasing rate of change for mandibular volume and increasing root volume. Results show that as patient's weight increases, the mandible and root volumes increase at different rates. Root percentage by volume at all three locations was noted to decrease by the same rate. Canine and M1 roots are proportionally larger than the supporting mandibular bone in smaller patients. Care should be taken to recommend periodontal disease prevention for owners of small dogs and consideration made when performing extractions or other surgery that may destabilize the mandible.

Ameloblastic odontoma in the mandible of a llama

PubMed Central

Step, Douglas L.; Ritchey, Jerry W.; Drost, William Tod; Bahr, Robert J.

2003-01-01

A 4-year-old llama had an aggressive, multiloculated, expansile bone lesion involving the rostral mandible. The mandibular lesion was imaged using radiography and computed tomography. Antemortem diagnosis of an ossifying fibroma was made histologically. Postmortem findings showed the lesion to be limited to the mandible. Final diagnosis was ameloblastic odontoma. PMID:14601679

Does shape co-variation between the skull and the mandible have functional consequences? A 3D approach for a 3D problem

PubMed Central

Cornette, Raphaël; Baylac, Michel; Souter, Thibaud; Herrel, Anthony

2013-01-01

Morpho-functional patterns are important drivers of phenotypic diversity given their importance in a fitness-related context. Although modularity of the mandible and skull has been studied extensively in mammals, few studies have explored shape co-variation between these two structures. Despite being developmentally independent, the skull and mandible form a functionally integrated unit. In the present paper we use 3D surface geometric morphometric methods allowing us to explore the form of both skull and mandible in its 3D complexity using the greater white-toothed shrew as a model. This approach allows an accurate 3D description of zones devoid of anatomical landmarks that are functionally important. Two-block partial least-squares approaches were used to describe the co-variation of form between skull and mandible. Moreover, a 3D biomechanical model was used to explore the functional consequences of the observed patterns of co-variation. Our results show the efficiency of the method in investigations of complex morpho-functional patterns. Indeed, the description of shape co-variation between the skull and the mandible highlighted the location and the intensity of their functional relationships through the jaw adductor muscles linking these two structures. Our results also demonstrated that shape co-variation in form between the skull and mandible has direct functional consequences on the recruitment of muscles during biting. PMID:23964811

Dentomaxillofacial characteristics of ectodermal dysplasia.

PubMed

Nakayama, Yumiko; Baba, Yoshiyuki; Tsuji, Michiko; Fukuoka, Hiroki; Ogawa, Takuya; Ohkuma, Mizue; Moriyama, Keiji

2015-02-01

The aim of this retrospective hospital-based study was to elucidate the dentomaxillofacial characteristics of ectodermal dysplasia. Six Japanese individuals (one male and five female; age range, 12.7-27.2 years) underwent comprehensive examinations, including history recording, cephalometric analysis, panoramic radiography, and analysis of dental models. All the subjects had two or more major manifestations for clinical diagnosis of ectodermal dysplasia (e.g., defects of hair, teeth, nails, and sweat glands). They presented hypodontia (mean number of missing teeth, 9.5; range, 5-14), especially in the premolar region, and enamel dysplasia. Five subjects had bilateral molar occlusion, whereas one subject had unilateral molar occlusion. The common skeletal features were small facial height, maxillary hypoplasia, counterclockwise rotation of the mandible, and mandibular protrusion. Interestingly, the maxillary first molars were located in higher positions and the upper anterior facial height was smaller than the Japanese norm. The results suggest that vertical and anteroposterior maxillary growth retardation, rather than lack of occlusal support due to hypodontia, leads to reduced anterior facial height in individuals with ectodermal dysplasia. © 2014 Japanese Teratology Society.

The Archaeology of the Bug Hill Site (34Pu-116): Pushmataha County, Oklahoma.

DTIC Science & Technology

1982-01-01

parts of the left mandible. The post cranial skeleton consisted of two cervical, eight thoracic, three lumbar vertebrae, and qi 54 Figure 14. a: Feature...partial sacrilization of the fifth lumbar vertebrae. An unexplained anomaly is the antero-lateral amputation of the styloid process of the right temporal...CM U 5CM E 60 metatarsals, and 20 ribs were present. The vertebral column is repre- sented by five cervical, ten thoracic, five lumbar , and five

Melorheostosis and central giant cell granuloma of the mandible in a 15-year-old girl.

PubMed

Anderson, K M; Shintaku, W H; Rosebush, M S; Rawal, Y B; Woodard, E S

2013-11-01

Melorheostosis is a nonhereditary bone dysplasia primarily affecting the appendicular skeleton. Because clinical and histologic features are often nonspecific, the diagnosis is often based on the radiographic presentation. Involvement of the craniofacial skeleton is rare. We describe a case of a 15-year-old girl with appendicular and craniofacial melorheostosis with adjacent central giant cell granuloma. We discuss the possible significance of this previously unreported finding. Copyright © 2013 Elsevier Inc. All rights reserved.

Cortical Bone Morphological and Trabecular Bone Microarchitectural Changes in the Mandible and Femoral Neck of Ovariectomized Rats

PubMed Central

Hsu, Pei-Yu; Tsai, Ming-Tzu; Wang, Shun-Ping; Chen, Ying-Ju; Wu, Jay; Hsu, Jui-Ting

2016-01-01

Objective This study used microcomputed tomography (micro-CT) to evaluate the effects of ovariectomy on the trabecular bone microarchitecture and cortical bone morphology in the femoral neck and mandible of female rats. Materials and Methods Twelve female Wister rats were divided into two groups: the control and ovariectomized groups. The rats in the ovariectomized group received ovariectomy at 8 weeks of age; all the rats were sacrificed at 20 weeks of age, and their mandibles and femurs were removed and scanned using micro-CT. Four microstructural trabecular bone parameters were measured for the region below the first mandibular molar and the femoral neck region: bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular separation (TbSp), and trabecular number (TbN). In addition, four cortical bone parameters were measured for the femoral neck region: total cross-sectional area (TtAr), cortical area (CtAr), cortical bone area fraction (CtAr/TtAr), and cortical thickness (CtTh). The CtTh at the masseteric ridge was used to assess the cortical bone morphology in the mandible. The trabecular bone microarchitecture and cortical bone morphology in the femoral necks and mandibles of the control group were compared with those of the ovariectomized group. Furthermore, Spearman’s correlation (rs) was conducted to analyze the correlation between the osteoporosis conditions of the mandible and femoral neck. Results Regarding the trabecular bone microarchitectural parameters, the BV/TV of the trabecular bone microarchitecture in the femoral necks of the control group (61.199±11.288%, median ± interquartile range) was significantly greater than that of the ovariectomized group (40.329±5.153%). Similarly, the BV/TV of the trabecular bone microarchitecture in the mandibles of the control group (51.704±6.253%) was significantly greater than that of the ovariectomized group (38.486±9.111%). Furthermore, the TbSp of the femoral necks in the ovariectomized group (0.185±0.066 mm) was significantly greater than that in the control group (0.130±0.026mm). Similarly, the TbSp of the mandibles in the ovariectomized group (0.322±0.047mm) was significantly greater than that in the control group (0.285±0.041mm). However, the TbTh and TbN trends for the mandibles and femoral necks were inconsistent between the control and ovariectomized groups. Regarding the cortical bone morphology parameters, the TtAr of the femoral necks in the ovariectomized group was significantly smaller than that in the control group. There was no significant difference in the TtAr, CtAr, or CtTh of the femoral necks between the control and ovariectomized groups, and no significant difference in the CtTh of the mandibles between the control and ovariectomized groups. Moreover, the BV/TV and TbSp of the mandibles were highly correlated with those of the femurs (rs = 0.874 and rs = 0.755 for BV/TV and TbSp, respectively). Nevertheless, the TbTh, TbN, and CtTh of the mandibles were not correlated with those of the femoral necks. Conclusion After the rats were ovariectomized, osteoporosis of the trabecular bone microarchitecture occurred in their femurs and mandibles; however, ovariectomy did not influence the cortical bone morphology. In addition, the parametric values of the trabecular bone microarchitecture in the femoral necks were highly correlated with those of the trabecular bone microarchitecture in the mandibles. PMID:27127909

Reactive lesions of oral cavity: A retrospective study of 659 cases.

PubMed

Babu, Biji; Hallikeri, Kaveri

2017-01-01

This study reviews, analyzes, and compares the demographic data, histopathological features and discusses the treatment and prognosis of reactive lesions (RLs). Retrospective study was performed on the departmental archives from July 2006 to July 2016 (total 5000 cases) comprising of 659 cases of RLs of the oral cavity. The recorded data included age, gender, size, site, duration, habits, etiology, histopathological diagnosis, treatment, and prognosis. The most common lesion was found to be inflammatory fibrous hyperplasia (47%) followed by pyogenic granuloma (PG) (27.16%) and the least cases were of peripheral giant cell granuloma (1.6%). The mean age for the occurrence was 4th-5th decade in all the RL's exceptperipheral ossifying fibroma (POF) which presented in the third decade. Female predominance was noted in all lesions except irritational FIB. The sizes of majority of the lesions were approximately 0.5-1 cm. The common sites were anterior maxilla followed by posterior mandible and least in tongue with no associated habits (82.2%). The duration of all the lesions was seen to be <1 year. Majority of them presented with poor oral hygiene status (87.2%). Recurrences were present in 13.5% of surgically excised lesions. The RLs present commonly in oral cavity secondary to injury and local factors which can mimic benign to rarely malignant lesions. The clinical and histopathological examination helps to categorize the type of lesions. The complete removal of local irritants with follow-up and maintenance of oral hygiene helps to prevent the recurrences of such lesions.

The mandible and its foramen: anatomy, anthropology, embryology and resulting clinical implications.

PubMed

Lipski, M; Tomaszewska, I M; Lipska, W; Lis, G J; Tomaszewski, K A

2013-11-01

The aim of this paper is to summarise the knowledge about the anatomy, embryology and anthropology of the mandible and the mandibular foramen and also to highlight the most important clinical implications of the current studies regarding anaesthesia performed in the region of the mandible. An electronic journal search was undertaken to identify all the relevant studies published in English. The search included MEDLINE and EMBASE databases and years from 1950 to 2012. The subject search used a combination of controlled vocabulary and free text based on the search strategy for MEDLINE using key words: 'mandible', 'mandibular', 'foramen', 'anatomy', 'embryology', 'anthropology', and 'mental'. The reference lists of all the relevant studies and existing reviews were screened for additional relevant publications. Basing on relevant manuscripts, this short review about the anatomy, embryology and anthropology of the mandible and the mandibular foramen was written.

Ectopic third molars in the sigmoid notch: etiology, diagnostic imaging and treatment options.

PubMed

Hanisch, Marcel; Fröhlich, Leopold F; Kleinheinz, Johannes

2016-12-06

The etiology of ectopic third molars located in the sigmoid notch of the mandible is unclear. Only a few cases have been reported. The aim of this article is to discuss the etiology as well as treatment options and diagnostic imaging techniques. A PubMed and Medline search of the literature from 1965 to 2015 to ectopic third molars in the mandibular notch was performed. Furthermore, a clinical case provided by the authors is reported. Among the eight reviewed cases, two male and six female patients were affected that ranged from 25 to 62 years of age (mean 48.4). Pain and swelling in the preauricular region or trismus but also the absence of symptoms was reported. Only in two of the summarized articles an extra-oral access for the removal of the tooth was used. The etiology seems to be individually different, however dentigerous cysts and chronic inflammation seem to play an important role in their appearance. While previous diagnostic reports described two-dimensional diagnostic imaging, currently the three-dimensional imaging is common for preoperative surgical planning with respect to removing ectopic molars. Ectopic third molars in the mandible are a rare condition. The etiology seems to be individually different. Nowadays, three-dimensional imaging is common for preoperative surgical planning.

A domestic porcine model for studying the effects of radiation on head and neck cancers.

PubMed

Arnold, Christoph R; Kloss, Frank; Singh, Sarvpreet; Vasiljevic, Danijela; Stigler, Robert; Auberger, Thomas; Wenzel, Volker; Klima, Günter; Lukas, Peter; Lepperdinger, Günter; Gassner, Robert

2017-05-01

Radiation therapy (RT) of the head and neck region is often accompanied by serious side effects. Research in this area is needed to improve treatment outcomes and ameliorate therapy tolerance. Laboratory rodents are barely matching today's clinical standards in RT research. Yet domestic swine (Sus scrofa domestica) have previously proved suitable for various advanced tests in clinical research and training. We therefore investigated whether S. scrofa domestica is also appropriate for irradiation of the mandible. A common scheme for irradiation treatment of S. scrofa domestica mandibles in a split-mouth design was acquired by applying computed tomography (CT) scanning under sedation. Basing on close anatomic resemblance, a standard treatment plan comprising 2 opposed irradiation fields could be accomplished. RT was carried out in a clinical environment with 2 × 9 Gy. The resulting operating procedure facilitated complication-free sedation, transport, positioning, CT scanning, and effective irradiation. Based on common standards applied for RT in humans, domestic pigs can be employed to progress RT clinical research. Due to their human-like anatomy, physiology, size, and weight, the swine model is expedient for advancing experimental RT of the head and neck area. Copyright © 2016 Elsevier Inc. All rights reserved.

Statistical Analysis of Interactive Surgical Planning Using Shape Descriptors in Mandibular Reconstruction with Fibular Segments

PubMed Central

2016-01-01

This study was performed to quantitatively analyze medical knowledge of, and experience with, decision-making in preoperative virtual planning of mandibular reconstruction. Three shape descriptors were designed to evaluate local differences between reconstructed mandibles and patients’ original mandibles. We targeted an asymmetrical, wide range of cutting areas including the mandibular sidepiece, and defined a unique three-dimensional coordinate system for each mandibular image. The generalized algorithms for computing the shape descriptors were integrated into interactive planning software, where the user can refine the preoperative plan using the spatial map of the local shape distance as a visual guide. A retrospective study was conducted with two oral surgeons and two dental technicians using the developed software. The obtained 120 reconstruction plans show that the participants preferred a moderate shape distance rather than optimization to the smallest. We observed that a visually plausible shape could be obtained when considering specific anatomical features (e.g., mental foramen. mandibular midline). The proposed descriptors can be used to multilaterally evaluate reconstruction plans and systematically learn surgical procedures. PMID:27583465

Congenital muscle dystrophy and diet consistency affect mouse skull shape differently.

PubMed

Spassov, Alexander; Toro-Ibacache, Viviana; Krautwald, Mirjam; Brinkmeier, Heinrich; Kupczik, Kornelius

2017-11-01

The bones of the mammalian skull respond plastically to changes in masticatory function. However, the extent to which muscle function affects the growth and development of the skull, whose regions have different maturity patterns, remains unclear. Using muscle dissection and 3D landmark-based geometric morphometrics we investigated the effect of changes in muscle function established either before or after weaning, on skull shape and muscle mass in adult mice. We compared temporalis and masseter mass and skull shape in mice with a congenital muscle dystrophy (mdx) and wild type (wt) mice fed on either a hard or a soft diet. We found that dystrophy and diet have distinct effects on the morphology of the skull and the masticatory muscles. Mdx mice show a flattened neurocranium with a more dorsally displaced foramen magnum and an anteriorly placed mandibular condyle compared with wt mice. Compared with hard diet mice, soft diet mice had lower masseter mass and a face with more gracile features as well as labially inclined incisors, suggesting reduced bite strength. Thus, while the early-maturing neurocranium and the posterior portion of the mandible are affected by the congenital dystrophy, the late-maturing face including the anterior part of the mandible responds to dietary differences irrespective of the mdx mutation. Our study confirms a hierarchical, tripartite organisation of the skull (comprising neurocranium, face and mandible) with a modular division based on development and function. Moreover, we provide further experimental evidence that masticatory loading is one of the main environmental stimuli that generate craniofacial variation. © 2017 Anatomical Society.

Clinical experiences with laser-welded titanium frameworks supported by implants in the edentulous mandible: a 10-year follow-up study.

PubMed

Ortorp, Anders; Jemt, Torsten

2006-01-01

Long-term follow-up studies for more than 5 years are not available on laser-welded titanium frameworks. To report and compare 10-year data on implant-supported prostheses in the edentulous mandible provided with laser-welded titanium frameworks and conventional gold alloy frameworks. Altogether, 155 patients were consecutively treated with prostheses at abutment level with two generations of fixed laser-welded titanium frameworks (test groups). A control group of 53 randomly selected patients with conventional gold alloy castings was used for comparison. Clinical and radiographic 10-year data were collected for the three groups. All patients followed-up for 10 years (n=112) still had fixed prostheses in the mandible (cumulative success rate [CSR] 100%). The overall 10-year cumulative success rate (CSR) was 92.8 and 100.0% for titanium and gold alloy frameworks, respectively. Ten-year implant cumulative survival rate (CSR) was 99.4 and 99.6% for the test and control groups, respectively. Average 10-year bone loss was 0.56 (SD 0.45) mm for the titanium group and 0.77 (SD 0.36) mm for the control group (p < 0.05). The most common complications for titanium frameworks were resin or veneer fractures, soft tissue inflammation, and fractures (12.9%) of the metal frame. Loose and fractured implant screw components were below 3%. Excellent overall long-term results with 100% CSR could be achieved with the present treatment modality. Fractures of the metal frames and remade prostheses were more common for the laser-welded titanium frameworks, and the first generation of titanium frameworks worked poorly when compared with gold alloy frameworks during 10 years (p < 0.05). However, on average more bone loss was observed for implants supporting gold alloy frameworks during 10 years. The reasons for this difference are not clear.

Patterns of Pediatric Mandible Fractures in the United States.

PubMed

Owusu, James A; Bellile, Emily; Moyer, Jeffrey S; Sidman, James D

2016-01-01

The mandible is arguably the most frequently fractured facial bone in children. However, facial fractures are rare in children compared with adults, resulting in few large studies on patterns of pediatric facial fractures. To report the patterns, demographics, and cause of pediatric mandible fractures across the United States. A retrospective analysis was conducted of the Healthcare Cost and Utilization Project's National Emergency Department Sample from January 1 to December 31, 2012, using the International Classification of Disease, Ninth Revision, codes for mandible fractures (802.20-802.39) among patients 18 years and younger who presented to emergency departments. Demographics, fracture site, and fracture mechanism were analyzed to identify factors associated with fractures. Analysis was conducted from July 9 to July 28, 2015. There were 1984 records, representing a weighted estimate of 8848 cases of pediatric mandible fracture. The mean patient age was 14.0 years (95% CI, 13.6-14.3). The male to female ratio was 4:1 and females were comparatively younger, with a mean age of 12.5 years (95% CI, 11.8-13.1; P < .001). The most frequently fractured sites were the condyle, in 1288 patients (14.6% [95% CI, 12.6%-16.5%]), and the angle, in 1252 patients (14.1% [12.4%-15.9%]). Associated intracranial injuries occurred in 756 patients (8.5% [7.1%-10.0%]), and cervical spine fractures occurred in 393 (4.4% [3.5%-5.4%]). The fracture site and mechanism of injury varied with age and sex. For patients 12 years and younger, the most frequent fracture site was the condyle, accounting for 636 fractures (27.9% [24.2%-31.6%]), and the most frequent cause was falls, accounting for 692 fractures (30.3% [25.9%-34.8%]). In teenaged patients (13-18 years), the angle was the most frequent fracture site, accounting for 1157 fractures (17.6% [15.6%-19.6%]), and the most frequent cause was assault, accounting for 2619 fractures (39.9% [36.4%-43.3%]). For male patients, the angle was the predominant site, accounting for 1053 fractures (15.0% [13.1%-16.8%]), and the leading cause was assault, accounting for 2360 fractures (33.5% [30.2%-36.9%]). For female patients, the condyle was the most frequent site, accounting for 369 fractures (20.3% [16.0%-24.6%]), and the leading cause was falls, accounting for 422 fractures (23.2% [18.6%-28.0%]). In this study, age and sex disparities among pediatric mandible fractures were identified. Younger patients and female patients tend to have condyle fractures caused more commonly by falls while older patients and male patients tend to have angle fractures caused by assault. NA.

A custom-made temporomandibular joint prosthesis for fabrication by selective laser melting: Finite element analysis.

PubMed

Xu, Xiangliang; Luo, Danmei; Guo, Chuanbin; Rong, Qiguo

2017-08-01

A novel and custom-made selective laser melting (SLM) 3D-printed alloplastic temporomandibular joint (TMJ) prosthesis is proposed. The titanium-6aluminium-4vanadium (Ti-6Al-4V) condyle component and ultra-high molecular weight polyethylene (UHMWPE) fossa component comprised the total alloplastic TMJ replacement prosthesis. For the condyle component, an optimized tetrahedral open-porous scaffold with combined connection structures, i.e. an inlay rod and an onlay plate, between the prosthesis and remaining mandible was designed. The trajectory of movement of the intact condyle was assessed via kinematic analysis to facilitate the design of the fossa component. The behaviours of the intact mandible and mandible with the prosthesis were compared. The biomechanical behaviour was analysed by assessing the stress distribution on the prosthesis and strain distribution on the mandible. After muscle force was applied, the magnitude of the compressive strain on the condyle neck of the mandible with the prosthesis was lower than that on the condyle neck of the intact mandible, with the exception of the area about the screws; additionally, the magnitude of the strain at the scaffold-bone interface was relatively high. Copyright © 2017. Published by Elsevier Ltd.

Failure location prediction by finite element analysis for an additive manufactured mandible implant.

PubMed

Huo, Jinxing; Dérand, Per; Rännar, Lars-Erik; Hirsch, Jan-Michaél; Gamstedt, E Kristofer

2015-09-01

In order to reconstruct a patient with a bone defect in the mandible, a porous scaffold attached to a plate, both in a titanium alloy, was designed and manufactured using additive manufacturing. Regrettably, the implant fractured in vivo several months after surgery. The aim of this study was to investigate the failure of the implant and show a way of predicting the mechanical properties of the implant before surgery. All computed tomography data of the patient were preprocessed to remove metallic artefacts with metal deletion technique before mandible geometry reconstruction. The three-dimensional geometry of the patient's mandible was also reconstructed, and the implant was fixed to the bone model with screws in Mimics medical imaging software. A finite element model was established from the assembly of the mandible and the implant to study stresses developed during mastication. The stress distribution in the load-bearing plate was computed, and the location of main stress concentration in the plate was determined. Comparison between the fracture region and the location of the stress concentration shows that finite element analysis could serve as a tool for optimizing the design of mandible implants. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

PubMed Central

JARVIS, S.J.; GIANGRANDE, V.; BRENNAN, P.A.

2013-01-01

SUMMARY Mucoepidermoid carcinoma is the most common malignant salivary gland tumour. However, short series or individual case reports have identified this tumour in the maxilla, mandible, breast tissue and thymus. Mucoepidermoid carcinoma originates from minor salivary glands, and it is therefore surprising that it is not more commonly seen in the tonsil. To date, we believe there has been only one previously reported case in the world literature of mucoepidermoid carcinoma occurring in the tonsil 1. We present a very rare case of mucoepidermoid carcinoma arising from within the structure of the palatine tonsil, rather from the adjacent pharyngeal wall, together with a short review of the literature. PMID:24043918

Automated segmentation of dental CBCT image with prior-guided sequential random forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Li; Gao, Yaozong; Shi, Feng

Purpose: Cone-beam computed tomography (CBCT) is an increasingly utilized imaging modality for the diagnosis and treatment planning of the patients with craniomaxillofacial (CMF) deformities. Accurate segmentation of CBCT image is an essential step to generate 3D models for the diagnosis and treatment planning of the patients with CMF deformities. However, due to the image artifacts caused by beam hardening, imaging noise, inhomogeneity, truncation, and maximal intercuspation, it is difficult to segment the CBCT. Methods: In this paper, the authors present a new automatic segmentation method to address these problems. Specifically, the authors first employ a majority voting method to estimatemore » the initial segmentation probability maps of both mandible and maxilla based on multiple aligned expert-segmented CBCT images. These probability maps provide an important prior guidance for CBCT segmentation. The authors then extract both the appearance features from CBCTs and the context features from the initial probability maps to train the first-layer of random forest classifier that can select discriminative features for segmentation. Based on the first-layer of trained classifier, the probability maps are updated, which will be employed to further train the next layer of random forest classifier. By iteratively training the subsequent random forest classifier using both the original CBCT features and the updated segmentation probability maps, a sequence of classifiers can be derived for accurate segmentation of CBCT images. Results: Segmentation results on CBCTs of 30 subjects were both quantitatively and qualitatively validated based on manually labeled ground truth. The average Dice ratios of mandible and maxilla by the authors’ method were 0.94 and 0.91, respectively, which are significantly better than the state-of-the-art method based on sparse representation (p-value < 0.001). Conclusions: The authors have developed and validated a novel fully automated method for CBCT segmentation.« less

Marsupialization of a large dentigerous cyst in the mandible with orthodontic extrusion of three impacted teeth. A case report.

PubMed

Abu-Mostafa, Nedal; Abbasi, Arshad

2017-09-01

The dentigerous cyst (DC) is the most common type of developmental odontogenic cyst. It is usually asymptomatic and associated with the crown of an unerupted or impacted tooth. However, after a long duration, it is likely to cause significant bone resorption, cortical expansion, and tooth displacement. This report presents a large infected DC in the mandible of a 12-year-old female patient. The DC was located inferior to badly decayed primary molars and surrounded three impacted permanent teeth: canine, first premolar, which had a dilacerated root, and second premolar. The DC was treated successfully by marsupialization and extrusion of the impacted teeth. In conclusion, the combination of marsupialization with orthodontic extrusion is a conservative, efficient protocol that stimulates bone healing and promotes the eruption of cyst-associated teeth even if they are deeply impacted, crowded, or have a dilacerated root. Key words: Dentigerous cyst, marsupialization, impacted teeth, orthodontic extrusion, dilacerated root.

Outcomes of vascularized bone graft reconstruction of the mandible in bisphosphonate-related osteonecrosis of the jaws.

PubMed

Seth, Rahul; Futran, Neal D; Alam, Daniel S; Knott, P Daniel

2010-11-01

To describe the clinical entity and therapeutic challenges of bisphosphonate-related osteonecrosis of the jaws (BRONJ). The use of vascularized bone grafts for reconstruction of the mandible in extensive BRONJ is proposed. Multi-institutional retrospective review. Patients undergoing mandible reconstruction with vascularized bone grafts after segmental mandible resection for BRONJ were evaluated. Mandible reconstruction was only performed on patients with intractable pain, fistulae, or pathologic fracture and after failure of comprehensive conservative therapy. No patients had a history of primary or metastatic head and neck malignancy or radiation therapy. Bone union was established with follow-up radiography. Eleven patients met inclusion criteria. Mean patient age was 61.3 years. Median follow-up was 13.9 months. All patients had undergone therapy with bisphosphonates and had no other identifiable cause of mandible osteonecrosis. Preoperatively, pathologic mandible fractures were present in 73% of patients, and 36% had orocutaneous fistulae. Fibula osteocutaneous flaps were used in all cases with no failures. In all patients, bony union was demonstrated clinically and radiographically. Postoperative wound complications occurred in 36% of patients but were all treated successfully with conservative therapy. There was no BRONJ recurrence within the study follow-up period. Osteonecrosis is a significant complication of bisphosphonate therapy, and current literature does not support vascularized reconstruction. We demonstrate that vascularized bone graft reconstruction with the fibula free flap offers a high success rate of bony union and fistula closure and should be offered to selected patients with advanced cases of BRONJ.

Characterization of the perinatal mandible growth pattern: preliminary results.

PubMed

Remy, F; Godio-Raboutet, Y; Verna, E; Gorincour, G; Bonnaure, P; Adalian, P; Guyot, L; Thollon, L

2018-06-01

The fetal development of the mandible is nowadays quite understood, and it is already known that craniofacial growth reaches its highest rate during the first 5 years of postnatal life. However, there are very few data focusing on the perinatal period. Thus, the present article is addressing this concern by studying the mandible morphology and its evolution around the birth with a morphometric method. Thirty-one mandibles modelled in three dimensions from post-mortem CT-scans were analyzed. This sample was divided into two subgroups composed of, respectively, 15 fetuses (aged from 36 gestational weeks), and 16 infants (aged to 12 postnatal weeks). 17 distances, 3 angles, and 8 thicknesses were measured via the prior set of 14 landmarks, illustrating the whole mandible morphology. Although this methodology may depend on the image reconstruction quality, its reliability was demonstrated with low variability in the results. It highlighted two distinct growth patterns around birth: fetuses mandibles do not significantly evolve during the perinatal period, whereas, from the second postnatal weeks, most of the measurements increased in a homogeneous tendency and in correlation with age. The protocol developed in this study highlighted the morphologic evolution of the mandible around birth, identifying a different growth pattern from 2 postnatal weeks, probably because of the progressive activation of masticatory muscles and tongue. However, considering the small sample size, these results should be thorough, so identification and management of anatomic abnormalities could eventually be achieved.

An analysis of beak shape variation in two ages of domestic turkeys (Meleagris gallopavo) using landmark-based geometric morphometrics.

PubMed

Dalton, Hillary A; Wood, Benjamin J; Widowski, Tina M; Guerin, Michele T; Torrey, Stephanie

2017-01-01

The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak shape variation using geometric morphometrics. Dorsal and right lateral images were taken of 2442 turkeys at 6 and 18.5 weeks of age. Landmarks were digitized in tpsDig in three analyses of the dorsal upper mandible, lateral upper mandible, and lateral lower mandible shape of each turkey at both ages. The coordinate data were then subjected to a principal components analysis (PCA), multivariate regression, and a canonical variates analysis (CVA) with a Procrustes ANOVA in MorphoJ. For the dorsal images, three principal components (PCs) showed beak shape variation ranged from long, narrow, and pointed to short, wide, and blunt upper mandibles at both ages (6 weeks: 95.36%, 18.5 weeks: 92.21%). Three PCs showed the lateral upper mandible shape variation ranged from long, wide beaks with long, curved beak tips to short, narrow beaks with short, pointed beak tips at both ages (6 weeks: 94.91%, 18.5 weeks: 94.33%). Three PCs also explained 97.80% (6 weeks) and 97.11% (18.5 weeks) of the lateral lower mandible shape variation ranging from wide and round to narrow and thin lower mandibles with superior/inferior beak tip shifts. Beak size accounted for varying proportions of the beak shape variation (0.96-54.76%; P < 0.0001) in the three analyses of each age group. For all the analyses, the CVA showed sexual dimorphism in beak shape (P < 0.0001) with female upper mandibles appearing wider and blunter dorsally with long, curved beak tips laterally. Whereas male turkey upper mandibles had a narrow, pointed dorsal appearance and short, pointed beak tips laterally. Future applications of beak shape variability could have a genetic and welfare value by incorporating beak shape variation to select for specific turkey beak phenotypes as an alternative to beak treatment.

An analysis of beak shape variation in two ages of domestic turkeys (Meleagris gallopavo) using landmark-based geometric morphometrics

PubMed Central

Widowski, Tina M.; Guerin, Michele T.

2017-01-01

The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak shape variation using geometric morphometrics. Dorsal and right lateral images were taken of 2442 turkeys at 6 and 18.5 weeks of age. Landmarks were digitized in tpsDig in three analyses of the dorsal upper mandible, lateral upper mandible, and lateral lower mandible shape of each turkey at both ages. The coordinate data were then subjected to a principal components analysis (PCA), multivariate regression, and a canonical variates analysis (CVA) with a Procrustes ANOVA in MorphoJ. For the dorsal images, three principal components (PCs) showed beak shape variation ranged from long, narrow, and pointed to short, wide, and blunt upper mandibles at both ages (6 weeks: 95.36%, 18.5 weeks: 92.21%). Three PCs showed the lateral upper mandible shape variation ranged from long, wide beaks with long, curved beak tips to short, narrow beaks with short, pointed beak tips at both ages (6 weeks: 94.91%, 18.5 weeks: 94.33%). Three PCs also explained 97.80% (6 weeks) and 97.11% (18.5 weeks) of the lateral lower mandible shape variation ranging from wide and round to narrow and thin lower mandibles with superior/inferior beak tip shifts. Beak size accounted for varying proportions of the beak shape variation (0.96–54.76%; P < 0.0001) in the three analyses of each age group. For all the analyses, the CVA showed sexual dimorphism in beak shape (P < 0.0001) with female upper mandibles appearing wider and blunter dorsally with long, curved beak tips laterally. Whereas male turkey upper mandibles had a narrow, pointed dorsal appearance and short, pointed beak tips laterally. Future applications of beak shape variability could have a genetic and welfare value by incorporating beak shape variation to select for specific turkey beak phenotypes as an alternative to beak treatment. PMID:28934330

Anthropometric Analysis of the Face.

PubMed

Zacharopoulos, Georgios V; Manios, Andreas; Kau, Chung H; Velagrakis, George; Tzanakakis, George N; de Bree, Eelco

2016-01-01

Facial anthropometric analysis is essential for planning cosmetic and reconstructive facial surgery, but has not been available in detail for modern Greeks. In this study, multiple measurements of the face were performed on young Greek males and females to provide a complete facial anthropometric profile of this population and to compare its facial morphology with that of North American Caucasians. Thirty-one direct facial anthropometric measurements were obtained from 152 Greek students. Moreover, the prevalence of the various face types was determined. The resulting data were compared with those published regarding North American Caucasians. A complete set of average anthropometric data was obtained for each sex. Greek males, when compared to Greek females, were found to have statistically significantly longer foreheads as well as greater values in morphologic face height, mandible width, maxillary surface arc distance, and mandibular surface arc distance. In both sexes, the most common face types were mesoprosop, leptoprosop, and hyperleptoprosop. Greek males had significantly wider faces and mandibles than the North American Caucasian males, whereas Greek females had only significantly wider mandibles than their North American counterparts. Differences of statistical significance were noted in the head and face regions among sexes as well as among Greek and North American Caucasians. With the establishment of facial norms for Greek adults, this study contributes to the preoperative planning as well as postoperative evaluation of Greek patients that are, respectively, scheduled for or are to be subjected to facial reconstructive and aesthetic surgery.

The prevalence of crowding, attrition, midline discrepancies and premature tooth loss in the primary dentition of children in Jeddah, Saudi Arabia.

PubMed

Alamoudi, N

1999-01-01

The aim of the present study is to evaluate the prevalence of crowding, attrition, midline discrepancies and premature loss of primary molars in primary dentition of children resident in Jeddah, Saudi Arabia. Five hundred and two (502) children aged 4-6 years old residing in the city of Jeddah, Saudi Arabia provide the data for the analysis. Crowding was found in 14.7% of the subjects crowding in the maxilla occurred in 27 (5.4%) of the children, and 67 (13.4%) in the mandible. Simultaneous crowding in maxilla and mandible was present in 20 (3.98%) of the subject. The prevalence of crowding was significantly higher in the mandible than the maxilla (P > 0.01) and higher in male (P < 0.05). Midline shift was present in 10% of the children with females showing a significantly higher prevalence than the males (P < 0.001). Attrition was present in 167 (33.3%) of the children. One hundred and sixty children (31.9%) had attrition in enamel, and only 7(1.4%) had attrition, which exposed the dentin. Thirty-one (6.2%) out of 502 children had 51 (0.5%) missing teeth out of total number of 10,040 teeth. Tooth #84 was most commonly lost tooth (P < .025). Overall premature loss of 1st primary molars was found to be significantly higher than 2nd primary molars (P < .001).

Radiographic evaluation of anatomical variables in maxilla and mandible in relation to dental implant placement.

PubMed

Chandra, Poornima; Govindaraju, Poornima; Chowdhary, Ramesh

2016-01-01

Oral rehabilitation using implants is rapidly replacing tooth supported prostheses. The success of implants is largely dependent on the quality and quantity of alveolar bone. In this study, we assessed the location of limiting anatomical structures and the amount of alveolar bone available for implant placement. Six hundred digital panoramic radiographs (300 males and 300 females) of dentate patients aged between 15-60 years were selected from the archives. The radiographs were subdivided into 3 groups with age interval of 15 years. Then the location of mental foramen, anterior loop, mandibular canal and maxillary sinus was determined. The amount of bone available was measured in both maxilla and mandible in the premolar and molar regions. The mental foramen was most commonly located at the apex of the second premolar in both the genders. The anterior loop was more readily visible in the younger age group. The amount of bone available in the premolar and molar region of the mandible is nearly the same, while more bone is available in the premolar region of the maxilla. The location and morphology of anatomical structures of the jaws vary not only in different populations but also within the same population. The amount of bone available also showed variations in the same population and in the same individual on the right and left sides. The limiting anatomical structures govern the amount of bone available for possible implant placement.

Dentognathic remains of Australopithecus afarensis from Nefuraytu (Woranso-Mille, Ethiopia): Comparative description, geology, and paleoecological context.

PubMed

Haile-Selassie, Yohannes; Melillo, Stephanie M; Ryan, Timothy M; Levin, Naomi E; Saylor, Beverly Z; Deino, Alan; Mundil, Ronald; Scott, Gary; Mulugeta Alene; Gibert, Luis

2016-11-01

Australopithecus afarensis is the best-known and most dimorphic species in the early hominin fossil record. Here, we present a comparative description of new fossil specimens of Au. afarensis from Nefuraytu, a 3.330-3.207 million-years-old fossil collection area in the Woranso-Mille study area, central Afar, Ethiopia. These specimens include NFR-VP-1/29, one of the most complete mandibles assigned to the species thus far and among the largest mandibles attributed to Au. afarensis, likely representing a male individual. NFR-VP-1/29 retains almost all of the distinctive archaic features documented for Au. afarensis. These features include a posteriorly sloping symphysis, a low and rounded basally set inferior transverse torus, anterosuperiorly opening mental foramen, a lateral corpus hollow bound anteriorly by the C/P 3 jugae and posteriorly by the lateral prominence, and the ascending ramus arising high on the corpus. Dental morphology and metrics of the Nefuraytu specimens also falls within the range of Au. afarensis. The presence of this species at Woranso-Mille between 3.330 and 3.207 million years ago confirms the existence of this species in the area in close spatial and temporal proximity to other middle Pliocene hominin taxa such as the one represented by the Burtele foot (BRT-VP-2/73) and the recently named species Australopithecus deyiremeda. This has important implications for our understanding of middle Pliocene hominin diversity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bone remodelling in Neanderthal mandibles from the El Sidrón site (Asturias, Spain)

PubMed Central

Martinez-Maza, Cayetana; Rosas, Antonio; García-Vargas, Samuel; Estalrrich, Almudena; de la Rasilla, Marco

2011-01-01

Skull morphology results from the bone remodelling mechanism that underlies the specific bone growth dynamics. Histological study of the bone surface from Neanderthal mandible specimens of El Sidrón (Spain) provides information about the distribution of the remodelling fields (bone remodelling patterns or BRP) indicative of the bone growth directions. In comparison with other primate species, BRP shows that Neanderthal mandibles from the El Sidrón (Spain) sample present a specific BRP. The interpretation of this map allows inferences concerning the growth directions that explain specific morphological traits of the Neanderthal mandible, such as its quadrangular shape and the posterior location of the mental foramen. PMID:21307043

Fibre Bragg grating sensing and finite element analysis of the biomechanics of the mandible

NASA Astrophysics Data System (ADS)

Silva, J. C. C.; Ramos, A.; Carvalho, L.; Nogueira, R. N.; Ballu, A.; Mesnard, M.; Pinto, J. L.; Kalinowski, Hypolito J.; Simoes, J. A.

2005-05-01

This paper describes the application of fibre Bragg grating (FBG) sensors to measure strains at the outer surface of a mandible. The strains were correlated to identical ones obtained with a numerical finite element model. For this purpose, a synthetic mandible was used and 4 Bragg sensors were glued to the mandible. Strain patterns were assessed for different load configurations which included the forces of the masseter and temporal muscles and occlusion loads on different tooth (incisor, canine and molar). Overall the strains obtained using different measuring methods were identical, namely for the case of symmetric loading. When loading was non-symmetric, strain differences were observed at one sensor.

The edentulous mandible opposed by natural maxillary teeth: a report of six cases treated with implant-retained prostheses.

PubMed

Clark, R K; Comfort, M B

1994-01-01

Dental restoration of the edentulous mandible opposing natural maxillary teeth is often associated with a number of problems, particularly in the occlusion, and an accelerated rate of alveolar bone resorption in the edentulous mandible resulting from occlusal loading. The advent of osseointegrated implants would seem to provide a new means of treating these cases. Accordingly, the cases of six patients for whom either fixed partial dentures or over-dentures supported by Brånemark implants were provided, are reviewed. Three of the mandibles were normal and three had bone grafts. Results so far indicate that this is a viable alternative for treating such cases.

Complete Midline Cleft of Lower Lip, Mandible, Tongue, Floor of Mouth with Neck Contracture: A Case Report and Review of Literature

PubMed Central

Rao, Anantheswar Y. N.

2015-01-01

Midline cleft of the lower lip and mandible is an extremely rare condition. Since 1819, when the first case was reported by Couronne, fewer than 80 cases have been described in the world literature so far. The cleft has also been described as facial cleft no. 30 by Paul Tessier. The condition varies in severity from a mild variety in which there is a submucous cleft and notching in the lower lip to a severe variety, involving the tongue, floor of the mouth, mandible, absent hyoid, atrophic neck muscles, and sternum. In this case report, a female child having complete midline cleft of the lower lip and mandible, with bifid tongue stuck to the floor of the mouth, absent hyoid bone and flexion contracture band extending from the confluence of the tip of the tongue, floor of the mouth, cleft mandible to the manubrium sterni is described, with special emphasis on surgical planning and management. PMID:26576245

The use of computer-aided design/manufacturing (CAD/CAM) technology to aid in the reconstruction of congenitally deficient pediatric mandibles: A case series.

PubMed

Gougoutas, Alexander J; Bastidas, Nicholas; Bartlett, Scott P; Jackson, Oksana

2015-12-01

Microvascular reconstruction of the pediatric mandible, particularly when necessitated by severe, congenital hypoplasia, presents a formidable challenge. Complex cases, however, may be simplified by computer-aided design/computer-aided manufacturing (CAD/CAM) assisted surgical planning. This series represents the senior authors' preliminary experiences with CAD/CAM assisted, microvascular reconstruction of the pediatric mandible. Presented are two patients with hemifacial/bifacial microsomia, both with profound mandibular hypoplasia, who underwent CAD/CAM assisted reconstruction of their mandibles with vascularized fibula flaps. Surgical techniques, CAD/CAM routines employed, complications, and long-term outcomes are reported. Successful mandibular reconstructions were achieved in both patients with centralization of their native mandibles and augmentation of deficient mandibular subunits. No long-term complications were observed. CAD/CAM technology can be utilized in pediatric mandibular reconstruction, and is particularly beneficial in cases of profound, congenital hypoplasia requiring extensive, multi-planar, bony reconstructions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Elastic properties and apparent density of human edentulous maxilla and mandible

PubMed Central

Seong, Wook-Jin; Kim, Uk-Kyu; Swift, James Q.; Heo, Young-Cheul; Hodges, James S.; Ko, Ching-Chang

2009-01-01

The aim of this study aim was to determine whether elastic properties and apparent density of bone differ in different anatomical regions of the maxilla and mandible. Additional analyses assessed how elastic properties and apparent density were related. Four pairs of edentulous maxilla and mandibles were retrieved from fresh human cadavers. Bone samples from four anatomical regions (maxillary anterior, maxillary posterior, mandibular anterior, mandibular posterior) were obtained. Elastic modulus (EM) and hardness (H) were measured using the nano-indentation technique. Bone samples containing cortical and trabecular bone were used to measure composite apparent density (cAD) using Archimedes’ principle. Statistical analyses used repeated measures ANOVA and Pearson correlations. Bone physical properties differed between regions of the maxilla and mandible. Generally, mandible had higher physical property measurements than maxilla. EM and H were higher in posterior than in anterior regions; the reverse was true for cAD. Posterior maxillary cAD was significantly lower than that in the three other regions. PMID:19647417

Elastic properties and apparent density of human edentulous maxilla and mandible.

PubMed

Seong, W-J; Kim, U-K; Swift, J Q; Heo, Y-C; Hodges, J S; Ko, C-C

2009-10-01

The aim of this study was to determine whether elastic properties and apparent density of bone differ in different anatomical regions of the maxilla and mandible. Additional analyses assessed how elastic properties and apparent density were related. Four pairs of edentulous maxilla and mandibles were retrieved from fresh human cadavers. Bone samples from four anatomical regions (maxillary anterior, maxillary posterior, mandibular anterior, mandibular posterior) were obtained. Elastic modulus (EM) and hardness (H) were measured using the nano-indentation technique. Bone samples containing cortical and trabecular bone were used to measure composite apparent density (cAD) using Archimedes' principle. Statistical analyses used repeated measures ANOVA and Pearson correlations. Bone physical properties differed between regions of the maxilla and mandible. Generally, mandible had higher physical property measurements than maxilla. EM and H were higher in posterior than in anterior regions; the reverse was true for cAD. Posterior maxillary cAD was significantly lower than that in the three other regions.

A mixed odontogenic sarcoma: A challenging histopathologic case and brief review of the literature.

PubMed

Atarbashi-Moghadam, Saede; Lotfi, Ali; Mokhtari, Sepideh

2018-01-01

Ameloblastic fibro-odontosarcoma (AFOS) is an extremely rare malignant mixed odontogenic tumor. The ectomesenchymal part of the neoplasm shows malignancy, whereas the epithelial component is rather benign. In addition, small areas with deposition of enamel matrix and dentine material are seen. The rarity of this neoplasm and microscopic similarities with other malignant and benign tumors can lead to diagnostic problems. Here, we describe the histopathologic features of a new case of AFOS of the mandible in a 34-year-old female patient. It is essential for oral pathologists to be familiar with the microscopic features of this rare neoplasm to have a proper diagnosis. This is also the first reported case of AFOS that closely resembles osteosarcoma in some areas.

Asymmetric larval head and mandibles of Hydrophilus acuminatus (Insecta: Coleoptera, Hydrophilidae): Fine structure and embryonic development.

PubMed

Sato, Shun'ichi; Inoda, Toshio; Niitsu, Shuhei; Kubota, Souichirou; Goto, Yuji; Kobayashi, Yukimasa

2017-11-01

The larvae of a water scavenger beetle, Hydrophilus acuminatus, have strongly asymmetric mandibles; the right one is long and slender, whereas the left one is short and stout. The fine structure and embryonic development of the head capsule and mandibles of this species were examined using light and scanning electron microscopy, and asymmetries in shape were detected in these structures applying an elliptic Fourier analysis. The larval mandibles are asymmetric in the following aspects: whole length, the number, structure and arrangement of retinacula (inner teeth), and size and shape of both the molar and incisor regions. The larval head is also asymmetric; the left half of the head capsule is larger than the right, and the left adductor muscle of the mandible is much thicker than the right. The origin and developmental process of asymmetric mandibles were traced in developing embryos whose developmental period is about 270 h and divided into 10 stages. Mandibular asymmetries are produced by the cumulative effects of six stepwise modifications that occur from about 36% of the total developmental time onward. The significance of these modifications was discussed with respect to the functional advantages of asymmetries and the phylogeny of members of the Hydrophilidae. Copyright © 2017 Elsevier Ltd. All rights reserved.

A numerical simulation of the effect of using porous superelastic Nitinol and stiff Titanium fixation hardware on the bone remodeling

NASA Astrophysics Data System (ADS)

Raad, Bahram; Shayesteh Moghaddam, Narges; Elahinia, Mohammad

2016-04-01

The aim of this article is to investigate the effect of two different fixation hardware materials on bone remodeling after a mandibular reconstruction surgery and to restore the mandible's function, healthy appearance, mastication, swallowing, breathing, and speech. The hypothesis is that using fixation hardware with stiffness close to that of the surrounding bone will result in a more successful healing process in the mandible bone. The finite element model includes the material properties and forces of the cancellous bone, cortical bone, ligaments, muscles, and teeth. The reconstruction surgery is modeled by including the fixation hardware and the grafted bone. In the sectioned mandible, to best mimic the geometry of the mandible, two single barrel grafts are placed at the top of each other to form a double barrel graft set. Two different materials were used as the mandibular fixation parts, stiff Ti-6Al-4V, and porous superelastic Nickel-Titanium (NiTi) alloys. A comparison of these two alloys demonstrates that using porous NiTi alloy as the fixation part results in a faster healing pace. Furthermore, the density distribution in the mandibular bone after the healing process is more similar to the normal mandible density distribution. The simulations results indicate that the porous superelastic NiTi fixation hardware transfers and distributes the existing forces on the mandible bone more favorably. The probability of stress shielding and/or stress concentration decrease. This type of fixation hardware, therefore, is more appropriate for mandible bone reconstruction surgery. These predictions are in agreement with the clinical observations.

Effect of the mandible on mouthguard measurements of head kinematics.

PubMed

Kuo, Calvin; Wu, Lyndia C; Hammoor, Brad T; Luck, Jason F; Cutcliffe, Hattie C; Lynall, Robert C; Kait, Jason R; Campbell, Kody R; Mihalik, Jason P; Bass, Cameron R; Camarillo, David B

2016-06-14

Wearable sensors are becoming increasingly popular for measuring head motions and detecting head impacts. Many sensors are worn on the skin or in headgear and can suffer from motion artifacts introduced by the compliance of soft tissue or decoupling of headgear from the skull. The instrumented mouthguard is designed to couple directly to the upper dentition, which is made of hard enamel and anchored in a bony socket by stiff ligaments. This gives the mouthguard superior coupling to the skull compared with other systems. However, multiple validation studies have yielded conflicting results with respect to the mouthguard׳s head kinematics measurement accuracy. Here, we demonstrate that imposing different constraints on the mandible (lower jaw) can alter mouthguard kinematic accuracy in dummy headform testing. In addition, post mortem human surrogate tests utilizing the worst-case unconstrained mandible condition yield 40% and 80% normalized root mean square error in angular velocity and angular acceleration respectively. These errors can be modeled using a simple spring-mass system in which the soft mouthguard material near the sensors acts as a spring and the mandible as a mass. However, the mouthguard can be designed to mitigate these disturbances by isolating sensors from mandible loads, improving accuracy to below 15% normalized root mean square error in all kinematic measures. Thus, while current mouthguards would suffer from measurement errors in the worst-case unconstrained mandible condition, future mouthguards should be designed to account for these disturbances and future validation testing should include unconstrained mandibles to ensure proper accuracy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bite of the cats: relationships between functional integration and mechanical performance as revealed by mandible geometry.

PubMed

Piras, Paolo; Maiorino, Leonardo; Teresi, Luciano; Meloro, Carlo; Lucci, Federico; Kotsakis, Tassos; Raia, Pasquale

2013-11-01

Cat-like carnivorous mammals represent a relatively homogeneous group of species whose morphology appears constrained by exclusive adaptations for meat eating. We present the most comprehensive data set of extant and extinct cat-like species to test for evolutionary transformations in size, shape and mechanical performance, that is, von Mises stress and surface traction, of the mandible. Size and shape were both quantified by means of geometric morphometrics, whereas mechanical performance was assessed applying finite element models to 2D geometry of the mandible. Additionally, we present the first almost complete composite phylogeny of cat-like carnivorans for which well-preserved mandibles are known, including representatives of 35 extant and 59 extinct species of Felidae, Nimravidae, and Barbourofelidae. This phylogeny was used to test morphological differentiation, allometry, and covariation of mandible parts within and among clades. After taking phylogeny into account, we found that both allometry and mechanical variables exhibit a significant impact on mandible shape. We also tested whether mechanical performance was linked to morphological integration. Mechanical stress at the coronoid process is higher in sabertoothed cats than in any other clade. This is strongly related to the high degree of covariation within modules of sabertooths mandibles. We found significant correlation between integration at the clade level and per-clade averaged stress values, on both original data and by partialling out interclade allometry from shapes when calculating integration. This suggests a strong interaction between natural selection and the evolution of developmental and functional modules at the clade level.

Comparison of 3D reconstruction of mandible for pre-operative planning using commercial and open-source software

NASA Astrophysics Data System (ADS)

Abdullah, Johari Yap; Omar, Marzuki; Pritam, Helmi Mohd Hadi; Husein, Adam; Rajion, Zainul Ahmad

2016-12-01

3D printing of mandible is important for pre-operative planning, diagnostic purposes, as well as for education and training. Currently, the processing of CT data is routinely performed with commercial software which increases the cost of operation and patient management for a small clinical setting. Usage of open-source software as an alternative to commercial software for 3D reconstruction of the mandible from CT data is scarce. The aim of this study is to compare two methods of 3D reconstruction of the mandible using commercial Materialise Mimics software and open-source Medical Imaging Interaction Toolkit (MITK) software. Head CT images with a slice thickness of 1 mm and a matrix of 512x512 pixels each were retrieved from the server located at the Radiology Department of Hospital Universiti Sains Malaysia. The CT data were analysed and the 3D models of mandible were reconstructed using both commercial Materialise Mimics and open-source MITK software. Both virtual 3D models were saved in STL format and exported to 3matic and MeshLab software for morphometric and image analyses. Both models were compared using Wilcoxon Signed Rank Test and Hausdorff Distance. No significant differences were obtained between the 3D models of the mandible produced using Mimics and MITK software. The 3D model of the mandible produced using MITK open-source software is comparable to the commercial MIMICS software. Therefore, open-source software could be used in clinical setting for pre-operative planning to minimise the operational cost.

Characterizing mandibular growth using three-dimensional imaging techniques and anatomic landmarks

PubMed Central

Kelly, Michael P.; Vorperian, Houri K.; Wang, Yuan; Tillman, Katelyn K.; Werner, Helen M.; Chung, Moo K.; Gentry, Lindell R.

2017-01-01

Objective To provide quantitative data on the multi-planar growth of the mandible, this study derived accurate linear and angular mandible measurements using landmarks on three dimensional (3D) mandible models. This novel method was used to quantify 3D mandibular growth and characterize the emergence of sexual dimorphism. Design Cross-sectional and longitudinal imaging data were obtained from a retrospective computed tomography (CT) database for 51 typically developing individuals between the ages of one and nineteen years. The software Analyze was used to generate 104 3DCT mandible models. Eleven landmarks placed on the models defined six linear measurements (lateral condyle, gonion, and endomolare width, ramus and mental depth, and mandible length) and three angular measurements (gonion, gnathion, and lingual). A fourth degree polynomial fit quantified growth trends, its derivative quantified growth rates, and a composite growth model determined growth types (neural/cranial and somatic/skeletal). Sex differences were assessed in four age cohorts, each spanning five years, to determine the ontogenetic pattern producing sexual dimorphism of the adult mandible. Results Mandibular growth trends and growth rates were non-uniform. In general, structures in the horizontal plane displayed predominantly neural/cranial growth types, whereas structures in the vertical plane had somatic/skeletal growth types. Significant prepubertal sex differences in the inferior aspect of the mandible dissipated when growth in males began to outpace that of females at eight to ten years of age, but sexual dimorphism re-emerged during and after puberty. Conclusions This 3D analysis of mandibular growth provides preliminary normative developmental data for clinical assessment and craniofacial growth studies. PMID:28161602

Insight of Dogs' Inner Mandible Anatomy using Mathematical Models.

PubMed

Santos, M; Carreira, L M

2016-12-01

This study was performed in a sample of 20 dogs (n = 20) and aimed to: (1) characterize the mandible height (Mh), mandibular canal height (MCh) and distance between the inter-dental alveolar margin and the mandibular canal (dIAM-MC) dimensions, and (2) to develop mathematical models that express the insight's mandible anatomy of those important mandible structural elements allowing the prediction of their dimensions using physical parameters such as patient body weight (Wg) and the canine tooth width at the free gingival margin level-(wCGM). Lateral-view X-rays of both sides of the skull were taken for all the individuals. Three mathematical prediction models were developed to calculate Mh, MCh and dIAM-MC. Achieved proportions of the mandible considered parameters regarding its height were of 36.45% for MCh, 50.90% for dMAI-MC and 12.65% for vMC. Statistically significant differences were registered between the Wg and wCGM (P = 0.00), Mh (P = 0.00), MCh (P = 0.00) and dIAM-MC (P = 0.00). Only the Wg presented a strong correlation with the wCGM (R = 0.58), Mh (R = 0.70), dIAM-MC (R = 0.60) and MCh (R = 0.68). These models will allow a clinician to estimate the size of the mandible structures by only using data obtained during the physiological examination, with a sufficiently high prediction capacity and a very low standard error. The study points out the relationships of physiological parameters such as Wg and wCGM with mandible anatomical structural elements considered as important in oral surgery. The results of this study give the surgeon a new additional tool providing more information on the mandible anatomical structures and its relationships. This reduces the risk of iatrogenic lesions during the oral surgical procedures and improves patient safety. © 2016 Blackwell Verlag GmbH.

“Partial duplication of lower lip and hemimandible” A rare case

PubMed Central

Nayak, Bibhuti Bhusan; Mohanty, Nilamani

2012-01-01

Duplication of mandible and lower lip is a very rare congenital entity. We report an extremely uncommon case of Congenital Duplication of Lower lip and Mandible in a 3 year old girl, who was treated surgically in a single stage for correction of both lip and mandible. This was a commissure preserving single staged procedure. The Surgical procedure, the problems related to this anomaly and the embryology are discussed. PMID:23450337

Focal cemento-osseous dysplasia masquerading as a residual cyst

PubMed Central

Bhandari, Rajat; Sandhu, Simarpreet V.; Bansal, Himanta; Behl, Rashi; Bhullar, Ramanpreet Kaur

2012-01-01

Focal cemento-osseous dysplasia (FCOD) is a benign fibroosseous condition that can be seen in dentulous and edentulous patients. It is an asymptomatic lesion and needs no treatment; however, follow-up is essential due to the possibility that it can progress to a condition called florid cemento-osseous dysplasia. We report a case of FCOD of mandible in a 25-year-old female. Clinically, the lesion resembled periapical pathosis of odontogenic origin. An attempt has been made to discuss the clinical and histopathologic features along with differential diagnosis of cemento-osseous dysplasia. PMID:22629069

Focal cemento-osseous dysplasia masquerading as a residual cyst.

PubMed

Bhandari, Rajat; Sandhu, Simarpreet V; Bansal, Himanta; Behl, Rashi; Bhullar, Ramanpreet Kaur

2012-04-01

Focal cemento-osseous dysplasia (FCOD) is a benign fibroosseous condition that can be seen in dentulous and edentulous patients. It is an asymptomatic lesion and needs no treatment; however, follow-up is essential due to the possibility that it can progress to a condition called florid cemento-osseous dysplasia. We report a case of FCOD of mandible in a 25-year-old female. Clinically, the lesion resembled periapical pathosis of odontogenic origin. An attempt has been made to discuss the clinical and histopathologic features along with differential diagnosis of cemento-osseous dysplasia.

Geometric morphometric analysis of allometric variation in the mandibular morphology of the hominids of Atapuerca, Sima de los Huesos site.

PubMed

Rosas, Antonio; Bastir, Markus

2004-06-01

Allometry is an important factor of morphological integration that contributes to the organization of the phenotype and its variation. Variation in the allometric shape of the mandible is particularly important in hominid evolution because the mandible carries important taxonomic traits. Some of these traits are known to covary with size, particularly the retromolar space, symphyseal curvature, and position of the mental foramen. The mandible is a well studied system in the context of the evolutionary development of complex morphological structures because it is composed of different developmental units that are integrated within a single bone. In the present study, we investigated the allometric variation of two important developmental units that are separated by the inferior nerve (a branch of CN V3). We tested the null hypothesis that there would be no difference in allometric variation between the two components. Procrustes-based geometric morphometrics of 20 two-dimensional (2D) landmarks were analyzed by multivariate regressions of shape on size in samples from 121 humans, 48 chimpanzees, and 50 gorillas (all recent specimens), eight fossil hominids from Atapuerca, Sima de los Huesos (AT-SH), and 17 Neandertals. The findings show that in all of the examined species, there was significantly greater allometric variation in the supra-nerve unit than in the infra-nerve unit. The formation of the retromolar space exhibited an allometric relationship with the supra-nerve unit in all of the species studied. The formation of the chin-like morphology is an "apodynamic" feature of the infra-nerve unit in the AT-SH hominids. The results of this study support the hypothesis that allometry contributes to the organization of variation in complex morphological structures. Copyright 2004 Wiley-Liss, Inc.

Microcephalia with mandibular and dental dysplasia in adult Zmpste24-deficient mice

PubMed Central

de Carlos, F; Varela, I; Germanà, A; Montalbano, G; Freije, J M P; Vega, J A; López-Otin, C; Cobo, J M

2008-01-01

ZMPSTE24 (also called FACE-1) is a zinc-metalloprotease involved in the post-translational processing of prelamin A to mature lamin A, a major component of the nuclear envelope. Mutations in the ZMPSTE24 gene or in that encoding its substrate prelamin A (LMNA) result in a series of human inherited diseases known collectively as laminopathies and showing regional or systemic manifestations (i.e. the Hutchinson–Gilford progeria syndrome). Typically, patients suffering some laminopathies show craniofacial or mandible anomalies, aberrant dentition or facial features characteristic of aged persons. To analyse whether Zmpste24−/– mice reproduce the cranial phenotype observed in humans due to mutations in ZMPSTE24or LMNA, we conducted a craniometric study based on micro-computer tomography (µCT) images. Furthermore, using simple radiology, µCT, µCT-densitometry and scanning electron microscopy, we analysed the mandible and the teeth from Zmpste24−/– mice. Finally, the structure of the lower incisor was investigated using an H&E technique. The results demonstrate that Zmpste24−/– mice are microcephalic and show mandibular and dental dysplasia affecting only the mandible teeth. In all cases, the lower incisor of mice lacking Zmpste24 was smaller than in control animals, showed cylindrical morphology and a transverse fissure at the incisal edge, and the pulpal cavity was severely reduced. Structurally, the dental layers were normally arranged but cellular layers were disorganized. The inferior molars showed a reduced cusp size. Taken together, these data strongly suggest that Zmpste24−/– mice represent a good model to analyse the craniofacial and teeth malformations characteristic of lamin-related pathologies, and might contribute to a better understanding of the molecular events underlying these diseases. PMID:19014358

Do mandibular cross-sectional properties and dental microwear give similar dietary signals?

PubMed

Organ, Jason M; Ruff, Christopher B; Teaford, Mark F; Nisbett, Richard A

2006-08-01

Previous animal experimental work evaluating the effects of dietary consistency on mastication was generally limited to studies of either mandibular structure or rates and types of tooth wear. Control groups fed hard diets (HD) consistently exhibited increased cortical remodeling and/or bone strength when compared to groups fed soft diets (SD). Results of tooth-wear studies showed faster rates of tooth wear in HD animals. This study evaluates the effects of dietary differences on both mandibular structural morphology and postcanine dental microwear in the same animals. We examined mandibles and dentitions from eight miniature swine, raised from 4 weeks to 9 months of age on HD and SD (n = 4, each group). Mandibular structural properties were calculated from peripheral quantitative computed tomography slices at the dp3-dp4 and dp4-M1 junctions. Dental microwear analysis was performed on mandibular lingual crushing facets of dp4 and M1, using photomicrographs of high-resolution casts taken at 500x magnification in a scanning electron microscope. Our results suggest that between the dp3-dp4 contact, HD animals have mandibles that are stronger and more rigid mediolaterally than SD animals. At the dp4-M1 contact, HD animals have mandibles that are stronger and more rigid mediolaterally, dorsoventrally, and in torsion than SD animals. Dental microwear results indicate that SD pigs have higher incidences of pitting and more overall microwear features on their premolars than do HD pigs, yet there are no significant differences in molar microwear morphology between the dietary groups. Near-significant correlations exist between pit size and dorsoventral bending strength, but only for HD pigs. These results suggest that dietary consistency significantly affects both mandibular structure and dental microwear, yet direct correlations between the two are complicated by a number of factors.

Microdamage of the cortical bone during mini-implant insertion with self-drilling and self-tapping techniques: a randomized controlled trial.

PubMed

Yadav, Sumit; Upadhyay, Madhur; Liu, Sean; Roberts, Eugene; Neace, William P; Nanda, Ravindra

2012-05-01

The purpose of this research was to evaluate microdamage accumulation after mini-implant placement by self-drilling (without a pilot hole) and self-tapping (screwed into a pilot hole) insertion techniques. The null hypothesis was that the mini-implant insertion technique would have no influence on microcrack accumulation and propagation in the cortical bones of the maxillae and mandibles of adult hounds. Mini-implants (n = 162; diameter, 1.6 mm; length, 6 mm) were placed in the maxillae and mandibles of 9 hounds (12-14 months old) with self-drilling and self-tapping insertion techniques. The techniques were randomly assigned to the left or the right side of each jaw. Each hound received 18 mini-implants (10 in the mandible, 8 in the maxilla). Histomorphometric parameters including total crack length and crack surface density were measured. The null hypothesis was rejected in favor of an alternate hypothesis: that the self-drilling technique results in more microdamage (microcracks) accumulation in the adjacent cortical bone in both the maxilla and the mandible immediately after mini-implant placement. A cluster level analysis was used to analyze the data on the outcome measured. Since the measurements were clustered within dogs, a paired-samples t test was used to analyze the average differences between insertion methods at both jaw locations. A significance level of 0.05 was used for both analyses. The self-drilling technique resulted in greater total crack lengths in both the maxilla and the mandible (maxilla: mean difference, 18.70 ± 7.04 μm/mm(2); CI, 13.29-24.11; mandible: mean difference, 22.98 ± 6.43 μm/mm(2); CI, 18.04-27.93; P <0.05), higher crack surface density in both the maxilla and the mandible (maxilla: mean difference, 10.39 ± 9.16 μm/mm(2); CI, 3.34-17.43; mandible: mean difference, 11.28 ± 3.41 μm/mm(2); CI, 8.65-13.90; P <0.05). This study demonstrated greater microdamage in the cortical bones of adult hounds in both the maxilla and the mandible by the self-drilling insertion technique compared with the self-tapping technique. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

[Normal and pathologic mandible development: practical deductions in maxillo-dento-facial orthopedics].

PubMed

Salagnac, Jean-Michel

2016-09-01

The mandible consists of different segments, each of which possess its own specific characteristics regarding emergence, ossification during growth and pathologies. Orthodontists need to be very familiar with these developmental anomalies if they are to avoid failure in their orthopedic or orthodontic treatments and in order to understand the reasons for the lack of success of "conventional" treatments. Each segment must develop correctly if the mandible is to achieve optimal development and occupy a normal position within the cranio-facial complex. The position of the mandible in the cranio-facial block is also conditioned by its attachment to the base of the skull. Combining a detailed semiologic study and a three-dimensional architectural and structural radiologic analysis of clinical cases, this article investigates the various anomalies affecting the mandibular segments and their impact on the craniofacial structure as a whole. An understanding of these anomalies and this analytical method can enable clinicians to perform early diagnosis, avoid undertaking orthopedic and orthodontic treatments which are likely to fail, understand the reasons for unsuccessful "conventional" treatments, provide an orthopedic-surgical guide and make it possible to inform patients correctly. Anomalies affecting the growth of the mandible and its position on the cranial base and their impact on cranio-facial skeletal balance are clearly revealed by structural and architectural analysis, which pinpoints the different clinical elements in skeletal Class II et III cases. In maxilla-dento-facial orthopedics when confronted with a pathology of mandibular origin, it is essential to carefully study the radiographs of each segment of the mandible, to seek out the minor forms of the anomalies and to calculate the position of the mandible on the cranial base relative to the neighboring structures; the skull, the cervical vertebrae and the maxilla. © EDP Sciences, SFODF, 2016.

Random Positional Variation Among the Skull, Mandible, and Cervical Spine With Treatment Progression During Head-and-Neck Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Peter H.; Ahn, Andrew I.; Lee, C. Joe

2009-02-01

Purpose: With 54{sup o} of freedom from the skull to mandible to C7, ensuring adequate immobilization for head-and-neck radiotherapy (RT) is complex. We quantify variations in skull, mandible, and cervical spine movement between RT sessions. Methods and Materials: Twenty-three sequential head-and-neck RT patients underwent serial computed tomography. Patients underwent planned rescanning at 11, 22, and 33 fractions for a total of 93 scans. Coordinates of multiple bony elements of the skull, mandible, and cervical spine were used to calculate rotational and translational changes of bony anatomy compared with the original planning scan. Results: Mean translational and rotational variations on rescanningmore » were negligible, but showed a wide range. Changes in scoliosis and lordosis of the cervical spine between fractions showed similar variability. There was no correlation between positional variation and fraction number and no strong correlation with weight loss or skin separation. Semi-independent rotational and translation movement of the skull in relation to the lower cervical spine was shown. Positioning variability measured by means of vector displacement was largest in the mandible and lower cervical spine. Conclusions: Although only small overall variations in position between head-and-neck RT sessions exist on average, there is significant random variation in patient positioning of the skull, mandible, and cervical spine elements. Such variation is accentuated in the mandible and lower cervical spine. These random semirigid variations in positioning of the skull and spine point to a need for improved immobilization and/or confirmation of patient positioning in RT of the head and neck.« less

Mandible-first sequence in bimaxillary orthognathic surgery: a systematic review.

PubMed

Borba, A M; Borges, A H; Cé, P S; Venturi, B A; Naclério-Homem, M G; Miloro, M

2016-04-01

The sequencing of bimaxillary orthognathic surgery remains controversial, although the traditional maxilla-first approach is performed routinely. The goal of this study was to present a systematic review of the mandible-first sequence in bimaxillary orthognathic surgery, to provide data that may assist in the decision as to which jaw should undergo osteotomy first in bimaxillary orthognathic surgery cases. A literature search was conducted for articles published in the English language, reporting the use of the altered sequence for bimaxillary orthognathic surgery (mandible-first), using the following descriptors: 'orthognathic' and 'double-jaw', 'orthognathic' and 'two-jaw', 'orthognathic' and 'mandible-first', 'orthognathic' and 'bimaxillary'. Eight hundred eighty-seven abstracts were initially identified and were evaluated for inclusion according to the proposed inclusion criteria. After evaluation of these abstracts and relevant references, six publications met the criteria for consideration. Performing mandible-first surgery in bimaxillary orthognathic cases dates back to the 1970s; however the decision regarding the jaw to be operated on first seems to rely on accurate preoperative planning based upon the surgeon's experience and preference. While there appear to be significant theoretical advantages to support the use of the altered orthognathic sequence (mandible-first), future prospective studies on its reliability, accuracy, and short- and long-term outcomes are required. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Preliminary observations on the mandibles of palaemonoid shrimp (Crustacea: Decapoda: Caridea: Palaemonoidea)

PubMed Central

De Grave, Sammy; Johnson, Magnus L.

2015-01-01

The mandibles of caridean shrimps have been widely studied in the taxonomy and functional biology of the group. Within the Palaemonoidea the mandibles reach a high level of structural diversity reflecting the diverse lifestyles within the superfamily. However, the majority of studies have been restricted to light microscopy, with the ultrastructure at finer levels poorly known. This study investigates the mandible of nine species belonging to six of the recognised families of the Palaemonoidea using SEM and analyses the results in a phylogenetic and dietary framework. The results of the study indicate that little phylogenetic information is conveyed by the structure of the mandible, but that its form is influenced by primary food sources of each species. With the exception of Anchistioides antiguensis, all species examined possessed cuticular structures at the distal end of the pars molaris (molar process). Five types of cuticular structures are recognised herein, each with a unique form, but variable in number, placement and arrangement. Each type is presumed to have a different function which is likewise related to diet. PMID:25825676

Surgical Management of Duplication of the Pituitary Gland-Plus Syndrome With Epignathus, Cleft Palate, Duplication of Mandible, and Lobulated Tongue.

PubMed

Noguchi, Tadahide; Sugiyama, Tomoko; Sasaguri, Ken-Ichi; Ono, Shigeru; Maeda, Kosaku; Nishino, Hiroshi; Jinbu, Yoshinori; Mori, Yoshiyuki

2017-03-01

A 1-day-old male infant was referred to our department for evaluation of multiple malformations in his oral cavity. He was diagnosed duplication of the pituitary gland-plus syndrome with epignathus, cleft palate, duplication of the mandible, and a lobulated tongue. A thumb-sized mass lesion was visible on the hard palate. The duplicated mandible and lower lip was fused at the midline. The alveolar ridge was protruding through a wide-cleft soft palate involving the uvula. Further examination showed a lobulated tongue, which was seen behind the duplicated part of the mandible. Five days after birth, tracheotomy and epignathus resection were performed. At 7 months of age, the excess tissue of the duplicated mandible was resected at the area of adhesion on the lingual side, and the duplicated tongue and lip were reconstructed. A palatoplasty was performed at 20 months of age. Thereafter, the patient's progress was uneventful, with no abnormality in swallowing. No recurrence of epignathus has been observed during 2 years of follow-up.

Reactive lesions of oral cavity: A retrospective study of 659 cases

PubMed Central

Babu, Biji; Hallikeri, Kaveri

2017-01-01

Objective: This study reviews, analyzes, and compares the demographic data, histopathological features and discusses the treatment and prognosis of reactive lesions (RLs). Materials and Methods: Retrospective study was performed on the departmental archives from July 2006 to July 2016 (total 5000 cases) comprising of 659 cases of RLs of the oral cavity. The recorded data included age, gender, size, site, duration, habits, etiology, histopathological diagnosis, treatment, and prognosis. Results: The most common lesion was found to be inflammatory fibrous hyperplasia (47%) followed by pyogenic granuloma (PG) (27.16%) and the least cases were of peripheral giant cell granuloma (1.6%). The mean age for the occurrence was 4th–5th decade in all the RL's exceptperipheral ossifying fibroma (POF) which presented in the third decade. Female predominance was noted in all lesions except irritational FIB. The sizes of majority of the lesions were approximately 0.5–1 cm. The common sites were anterior maxilla followed by posterior mandible and least in tongue with no associated habits (82.2%). The duration of all the lesions was seen to be <1 year. Majority of them presented with poor oral hygiene status (87.2%). Recurrences were present in 13.5% of surgically excised lesions. Conclusion: The RLs present commonly in oral cavity secondary to injury and local factors which can mimic benign to rarely malignant lesions. The clinical and histopathological examination helps to categorize the type of lesions. The complete removal of local irritants with follow-up and maintenance of oral hygiene helps to prevent the recurrences of such lesions. PMID:29456298

Evidence-based medicine: Mandible fractures.

PubMed

Morrow, Brad T; Samson, Thomas D; Schubert, Warren; Mackay, Donald R

2014-12-01

After studying this article, the participant should be able to: 1. Describe the anatomy and subunits of the mandible. 2. Review the cause and epidemiology of mandible fractures. 3. Discuss the preoperative evaluation and diagnostic imaging. 4. Understand the principles and techniques of mandible fracture reduction and fixation. The management of mandibular fractures has undergone significant improvement because of advancements in plating technology, imaging, and instrumentation. As the techniques in management continue to evolve, it is imperative for the practicing physician to remain up-to-date with the growing body of scientific literature. The objective of this Maintenance of Certification article is to present a review of the literature so that the physician may make treatment recommendation based on the best evidence available. Pediatric fractures have been excluded from this article.

Distinct characteristics of mandibular bone collagen relative to long bone collagen: relevance to clinical dentistry.

PubMed

Matsuura, Takashi; Tokutomi, Kentaro; Sasaki, Michiko; Katafuchi, Michitsuna; Mizumachi, Emiri; Sato, Hironobu

2014-01-01

Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

PubMed Central

Tokutomi, Kentaro; Sasaki, Michiko; Katafuchi, Michitsuna; Mizumachi, Emiri; Sato, Hironobu

2014-01-01

Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw. PMID:24818151

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odon-toma occurring in the same jaw

PubMed Central

Hosseini, Farzaneh Agha; Moslemi, Elham

2011-01-01

Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two non-painful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them. PMID:24765298

Central ossifying fibroma, periapical cemento-osseous dysplasia and complex odon-toma occurring in the same jaw.

PubMed

Hosseini, Farzaneh Agha; Moslemi, Elham

2011-05-16

Central ossifying fibroma is a rare, benign fibro-osseous lesion that arises from the periodontal ligament. Periapical cemento-osseous dysplasia is another variant of fibro-osseous lesion which occurs in the anterior region of the mandible of females. Odontoma is a benign odontogenic tumor that contains enamel, dentine cement and pulp tissue. A 46-year-old woman was referred to the Department of Oral Medicine, School of Dentistry, Tehran University of Medical Sciences, with two non-painful swellings on both sides of the mandible, which had been slowly growing over a period of one year. Our differential diagnosis was florid cemento-osseous dysplasia, focal cemento-osseous dysplasia for the right side, complex odontoma for the left side and periapical cement-osseous dysplasia for the anterior side. The historical feature revealed ossifying fibroma, complex odontoma and periapical cemento-osseous dysplasia. The occurrence of these three lesions in the same jaw has been rarely reported in the literature. The relationship between the occurrence of these three lesions is not obvious it could be coincidental. It seems that more case reports are needed to establish the relationship between them.

Fibular free flap reconstruction for the management of advanced bilateral mandibular osteoradionecrosis.

PubMed

Shan, Xiao-Feng; Li, Ru-Huang; Lu, Xu-Guang; Cai, Zhi-Gang; Zhang, Jie; Zhang, Jian-Guo

2015-03-01

Fibular osteoseptocutaneous flap has been widely used for unilateral mandibular reconstruction. However, reports about the effects of fibular osteoseptocutaneous flap for the reconstruction of bilateral mandibular defects are limited. In this study, we used free vascularized fibular flaps to successfully manage bilateral mandibular osteoradionecrosis(ORN) in 5 patients. Functional aspects were evaluated during the reconstruction process. All 5 patients had bilateral refractory ORN of the mandible and underwent radical resection between 2003 and 2011. The reconstruction surgery was performed in 2 stages using 2 free fibular flaps in 3 patients. In the other 2 patients, reconstruction was performed in a single stage using 2 separate flaps prepared from a single fibula. All patients had a healthy mandibular symphysis and meniscus of the temporomandibular joint, and these structures were preserved during the reconstruction.Of the 10 defects involving the mandible sides, 9 were successfully reconstructed. One microvascular composite flap failed because of radiation injury to the arterial endothelium at the recipient site. After the treatments, all patients had good esthetic and functional outcomes. Preoperative clinical features such as trismus and dysphagia were also markedly improved. Our surgical method may be an effective alternative for the clinical management of advanced bilateral mandibular ORN.

A mixed odontogenic sarcoma: A challenging histopathologic case and brief review of the literature

PubMed Central

Atarbashi-Moghadam, Saede; Lotfi, Ali; Mokhtari, Sepideh

2018-01-01

Ameloblastic fibro-odontosarcoma (AFOS) is an extremely rare malignant mixed odontogenic tumor. The ectomesenchymal part of the neoplasm shows malignancy, whereas the epithelial component is rather benign. In addition, small areas with deposition of enamel matrix and dentine material are seen. The rarity of this neoplasm and microscopic similarities with other malignant and benign tumors can lead to diagnostic problems. Here, we describe the histopathologic features of a new case of AFOS of the mandible in a 34-year-old female patient. It is essential for oral pathologists to be familiar with the microscopic features of this rare neoplasm to have a proper diagnosis. This is also the first reported case of AFOS that closely resembles osteosarcoma in some areas. PMID:29491601

Scaling of rotational inertia of primate mandibles.

PubMed

Ross, Callum F; Iriarte-Diaz, Jose; Platts, Ellen; Walsh, Treva; Heins, Liam; Gerstner, Geoffrey E; Taylor, Andrea B

2017-05-01

The relative importance of pendulum mechanics and muscle mechanics in chewing dynamics has implications for understanding the optimality criteria driving the evolution of primate feeding systems. The Spring Model (Ross et al., 2009b), which modeled the primate chewing system as a forced mass-spring system, predicted that chew cycle time would increase faster than was actually observed. We hypothesized that if mandibular momentum plays an important role in chewing dynamics, more accurate estimates of the rotational inertia of the mandible would improve the accuracy with which the Spring Model predicts the scaling of primate chew cycle period. However, if mass-related momentum effects are of negligible importance in the scaling of primate chew cycle period, this hypothesis would be falsified. We also predicted that greater "robusticity" of anthropoid mandibles compared with prosimians would be associated with higher moments of inertia. From computed tomography scans, we estimated the scaling of the moment of inertia (I j ) of the mandibles of thirty-one species of primates, including 22 anthropoid and nine prosimian species, separating I j into the moment about a transverse axis through the center of mass (I xx ) and the moment of the center of mass about plausible axes of rotation. We found that across primates I j increases with positive allometry relative to jaw length, primarily due to positive allometry of jaw mass and I xx , and that anthropoid mandibles have greater rotational inertia compared with prosimian mandibles of similar length. Positive allometry of I j of primate mandibles actually lowers the predictive ability of the Spring Model, suggesting that scaling of primate chew cycle period, and chewing dynamics in general, are more strongly influenced by factors other than scaling of inertial properties of the mandible, such as the dynamic properties of the jaw muscles and neural control. Differences in cycle period scaling between chewing and locomotion systems reinforce the suggestion that displacement and force control are more important in the design of feeding systems than energetics and speed. Copyright © 2017 Elsevier Ltd. All rights reserved.

An assessment of early mandibular growth.

PubMed

Hutchinson, E F; L'Abbé, E N; Oettlé, A C

2012-04-10

Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch and associated muscle attachment sites. These findings might be valuable in the estimation of age in unidentified individuals and to monitor prenatal growth of the mandible for the early diagnosis of conditions associated with stunted mandibular growth. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Adaptive plasticity in the mouse mandible.

PubMed

Anderson, Philip S L; Renaud, Sabrina; Rayfield, Emily J

2014-04-18

Plasticity, i.e. non-heritable morphological variation, enables organisms to modify the shape of their skeletal tissues in response to varying environmental stimuli. Plastic variation may also allow individuals to survive in the face of new environmental conditions, enabling the evolution of heritable adaptive traits. However, it is uncertain whether such a plastic response of morphology constitutes an evolutionary adaption itself. Here we investigate whether shape differences due to plastic bone remodelling have functionally advantageous biomechanical consequences in mouse mandibles. Shape characteristics of mandibles from two groups of inbred laboratory mice fed either rodent pellets or ground pellets mixed with jelly were assessed using geometric morphometrics and mechanical advantage measurements of jaw adductor musculature. Mandibles raised on diets with differing food consistency showed significant differences in shape, which in turn altered their biomechanical profile. Mice raised on a soft food diet show a reduction in mechanical advantage relative to mice of the same inbred strain raised on a typical hard food diet. Further, the soft food eaters showed lower levels of integration between jaw regions, particularly between the molar and angular region relative to hard food eaters. Bone remodelling in mouse mandibles allows for significant shifts in biomechanical ability. Food consistency significantly influences this process in an adaptive direction, as mice raised on hard food develop jaws better suited to handle hard foods. This remodelling also affects the organisation of the mandible, as mice raised on soft food appear to be released from developmental constraints showing less overall integration than those raised on hard foods, but with a shift of integration towards the most solicited regions of the mandible facing such a food, namely the incisors. Our results illustrate how environmentally driven plasticity can lead to adaptive functional changes that increase biomechanical efficiency of food processing in the face of an increased solicitation. In contrast, decreased demand in terms of food processing seems to release developmental interactions between jaw parts involved in mastication, and may generate new patterns of co-variation, possibly opening new directions to subsequent selection. Overall, our results emphasize that mandible shape and integration evolved as parts of a complex system including mechanical loading food resource utilization and possibly foraging behaviour.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

PubMed

Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei

2011-03-01

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Calcium phosphate mineralization is widely applied in crustacean mandibles.

PubMed

Bentov, Shmuel; Aflalo, Eliahu D; Tynyakov, Jenny; Glazer, Lilah; Sagi, Amir

2016-02-24

Crustaceans, like most mineralized invertebrates, adopted calcium carbonate mineralization for bulk skeleton reinforcement. Here, we show that a major part of the crustacean class Malacostraca (which includes lobsters, crayfishes, prawns and shrimps) shifted toward the formation of calcium phosphate as the main mineral at specified locations of the mandibular teeth. In these structures, calcium phosphate is not merely co-precipitated with the bulk calcium carbonate but rather creates specialized structures in which a layer of calcium phosphate, frequently in the form of crystalline fluorapatite, is mounted over a calcareous "jaw". From a functional perspective, the co-existence of carbonate and phosphate mineralization demonstrates a biomineralization system that provides a versatile route to control the physico-chemical properties of skeletal elements. This system enables the deposition of amorphous calcium carbonate, amorphous calcium phosphate, calcite and apatite at various skeletal locations, as well as combinations of these minerals, to form graded composites materials. This study demonstrates the widespread occurrence of the dual mineralization strategy in the Malacostraca, suggesting that in terms of evolution, this feature of phosphatic teeth did not evolve independently in the different groups but rather represents an early common trait.

Calcium phosphate mineralization is widely applied in crustacean mandibles

PubMed Central

Bentov, Shmuel; Aflalo, Eliahu D.; Tynyakov, Jenny; Glazer, Lilah; Sagi, Amir

2016-01-01

Crustaceans, like most mineralized invertebrates, adopted calcium carbonate mineralization for bulk skeleton reinforcement. Here, we show that a major part of the crustacean class Malacostraca (which includes lobsters, crayfishes, prawns and shrimps) shifted toward the formation of calcium phosphate as the main mineral at specified locations of the mandibular teeth. In these structures, calcium phosphate is not merely co-precipitated with the bulk calcium carbonate but rather creates specialized structures in which a layer of calcium phosphate, frequently in the form of crystalline fluorapatite, is mounted over a calcareous “jaw”. From a functional perspective, the co-existence of carbonate and phosphate mineralization demonstrates a biomineralization system that provides a versatile route to control the physico-chemical properties of skeletal elements. This system enables the deposition of amorphous calcium carbonate, amorphous calcium phosphate, calcite and apatite at various skeletal locations, as well as combinations of these minerals, to form graded composites materials. This study demonstrates the widespread occurrence of the dual mineralization strategy in the Malacostraca, suggesting that in terms of evolution, this feature of phosphatic teeth did not evolve independently in the different groups but rather represents an early common trait. PMID:26906263

Distraction osteogenesis and orthognathic surgery for a patient with unilateral cleft lip and palate.

PubMed

Kim, Ji Hyun; Lee, Il Hong; Lee, Sang Min; Yang, Byoung Eun; Park, In Young

2015-03-01

Maxillary deficiency is a common feature in patients with repaired cleft lip and palate. Orthognathic surgery has been the conventional approach for the management of cleft-related maxillary hypoplasia. However, for patients with a severe maxillary deficiency, orthognathic surgery alone has many disadvantages, such as high relapse rates of 25% to 40%, instability, limited amount of advancement, and a highly invasive surgical technique. As an alternative treatment method, distraction osteogenesis has been used successfully in the distraction of the mandible, the maxilla, the entire midface, and the orbits as well as the cranial bones, with stable outcomes. The type of distraction device, either external or internal, can be chosen based on the surgical goals set for the patient. In this study, we report on the use of a rigid external distraction device for maxillary advancement in a 22-year-old woman with a repaired unilateral cleft lip and palate and severe maxillary hypoplasia. After the distraction osteogenesis, 2-jaw surgery was performed to correct the maxillary yaw deviation and the mandibular prognathism. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Retrospective clinicopathological study of 418 odontogenic cysts.

PubMed

Nuñez-Urrutia, Sergio; Figueiredo, Rui; Gay-Escoda, Cosme

2010-09-01

To determine the relative incidence of odontogenic cysts and to identify the main clinicopathological features among patients treated in the Oral Surgery Department of the Dental Clinic of the University of Barcelona (Spain). A retrospective observational study was made of 418 odontogenic cysts diagnosed in 380 patients included in the database of 1235 histopathological diagnoses. The subjects were treated in the Master degree program of Oral Surgery and Implantology of the University of Barcelona in the period 1997-2006. The following variables were recorded: gender, age, clinical characteristics of the lesions (size and location), radiological features, duration, treatment, complications and relapses. A descriptive analysis was made of the study variables, using the SPSS version 15.0. The incidence of odontogenic cysts was 33.8%. The mean patient age at appearance of the lesion was 42 years (range 7-83). The cysts were slightly more prevalent in males (58.4%). The lesion size ranged from 2-60 mm, with a mean size of 18.4 mm. The most frequent diagnosis was radicular cyst (50.2%). The most common location of the odontogenic cysts was in the mandible (61.5%), particularly the lower third molar region (36.8%). The most frequently diagnosed lesion was the radicular cyst. Odontogenic cysts were seen to be slightly more prevalent in males, and showed a high mandibular incidence. Knowledge of the biological and histological behavior of odontogenic cysts and their frequency are key aspects for ensuring early detection and adequate treatment.

Complications and Reoperations in Mandibular Angle Fractures.

PubMed

Chen, Collin L; Zenga, Joseph; Patel, Ruchin; Branham, Gregory

2018-05-01

Mandible angle fractures can be repaired in a variety of ways, with no consensus on the outcomes of complications and reoperation rates. To analyze patient, injury, and surgical factors, including approach to the angle and plating technique, associated with postoperative complications, as well as the rate of reoperation with regard to mandible angle fractures. Retrospective cohort study analyzing the surgical outcomes of patients with mandible angle fractures between January 1, 2000, and December 31, 2015, who underwent open reduction and internal fixation. Patients were eligible if they were aged 18 years or older, had 3 or less mandible fractures with 1 involving the mandibular angle, and had adequate follow-up data. Patients with comminuted angle fractures, bilateral angle fractures, and multiple surgical approaches were excluded. A total of 135 patients were included in the study. All procedures were conducted at a single, large academic hospital located in an urban setting. Major complications and reoperation rates. Major complications included in this study were nonunion, malunion, severe malocclusion, severe infection, and exposed hardware. Of 135 patients 113 (83.7%) were men; median age was 29 years (range, 18-82 years). Eighty-seven patients (64.4%) underwent the transcervical approach and 48 patients (35.6%) received the transoral approach. Fifteen (17.2%) patients in the transcervical group and 9 (18.8%) patients in the transoral group experienced major complications (difference, 1%; 95% CI, -8% to 10%). Thirteen (14.9%) patients in the transcervical group and 8 (16.7%) patients in the transoral group underwent reoperations (difference, 2%; 95% CI, -13% to 17%). Active smoking had a significant effect on the rate of major complications (odds ratio, 4.04; 95% CI, 1.07 to 15.34; P = .04). During repair of noncomminuted mandibular angle fractures, both of the commonly used approaches-transcervical and transoral-can be used during treatment with equal rates of complication and risk of reoperation. For a patient undergoing surgery for mandibular angle fracture, smoking status is more likely to predict surgical outcomes rather than how the surgeon chooses to approach and fixate the fracture. 3.

[The application of the asymmetry index in assessment of mandible size in difficult diagnostic case].

PubMed

Syryńska, Maria; Szyszka, Liliana; Post, Marcin

2008-01-01

Recognised and unrecognised bone diseases including maxilla and/or mandible may have influance on formation of malocclusions. In first stages of diseases the patients are directed or report for orthodontic treatment which starting need additional examinations mainly pantomographic views. In spite doing necessary additional examinations sometimes we can't recognise disorder like patient presented in our study. Then we can observate and if changes will begin disturbing the function--surgical intervention. Establishment of orthodontic treatment plan and explanation if during three years the dimension of asymmetry resulting from wrong growth right and left part of mandible and the estimation the rate of changes happening in this time. In study we used the own asymmetry index to estimate the patient's pantomographic views who reported for orthodontic treatment because of occlusion disorders, facial asymmetry and discomfort of mastication and speech. The telerentgenographic lateral views in right and posterior-anterior (PA) projection were also done. We measured and estimated the own asymmetry index on pantomographic views. The radiographs reveal the asymmetry of left part of mandible. The comparative analysis of pantomographic views enables the estimation of changes happening in time and the telerentgenographic lateral views, PA and computer tomography (CT) confirm changes which increase the asymmetry. The asymmetry index is the instrument which enable the estimation of growth changes in mandible with unsteady aetiology and histopathological unrecognised, allow determine the growth rate and facilitate the permanent control the dimension of mandible asymmetry.

[Three-dimensional finite element study on the change of glossopharyngeum in patient with obstructive sleep apnea hypopnea syndrome during titrated mandible advancement].

PubMed

Yang, Suixing; Feng, Jing; Zhang, Zuo; Qu, Aili; Gong, Miao; Tang, Jie; Fan, Junheng; Li, Songqing; Zhao, Yanling

2013-04-01

To construct a three-dimensional finite element model of the upper airway and adjacent structure of an obstructive sleep apnea hypopnea syndrome (OSAHS) patient for biomechanical analysis. And to study the influence of glossopharyngeum of an OSAHS patient with three-dimensional finite element model during titrated mandible advancement. DICOM format image information of an OSAHS patient's upper airway was obtained by thin-section CT scanning and digital image processing were utilized to construct a three-dimensional finite element model by Mimics 10.0, Imageware 10.0 and Ansys software. The changes and the law of glossopharyngeum were observed by biomechanics and morphology after loading with titrated mandible advancement. A three-dimensional finite element model of the adjacent upper airway structure of OSAHS was established successfully. After loading, the transverse diameter of epiglottis tip of glossopharyngeum increased significantly, although the sagittal diameter decreased correspondingly. The principal stress was mainly distributed in anterior wall of the upper airway. The location of principal stress concentration did not change significantly with the increasing of distance. The stress of glossopharyngeum increased during titrated mandible advancement. A more precise three-dimensional finite model of upper airway and adjacent structure of an OSAHS patient is established and improved efficiency by Mimics, Imageware and Ansys software. The glossopharyngeum of finite element model of OSAHS is analyzed by titrated mandible advancement and can effectively show the relationship between mandible advancement and the glossopharyngeum.

[The influences upon the passive tensile of the masticatory muscles and ligaments by Herbst appliance under various bite reconstruction--a three dimensional finite element analysis].

PubMed

Song, J; Zhao, Z; Hu, L; Jiang, W; Fan, Y; Chen, J

2001-02-01

This study aimed to provide some biomechanical references for the clinical use and improvement of Herbst appliance. The three-dimensional model of the 'Temporomandibular joint mandible Herbst appliance system' was set up by SUPER SAP software (version 9.3). On this model, the passive tensile in the masticatory muscles and ligaments were analyzed under various bit reconstruction designed according to specified advanced displacement and vertical bite opening. When Herbst appliance drove the mandible forward, there was not any tensile in the medial, lateral pterygoid and the collateral ligament, while the temporalis, the deep paret of masseter, the stylomandibular ligament, and the sphenomandibular ligament were passively drawn. Under various bite reconstruction, the passive tensile in the medial temporalis, the posterior temporalis, the stylomandibular ligament and the sphenomandibular ligament increased with the amount of the advancement of the mandible; The passive tensile in the posterior temporalis and the deep part of masseter increased with the amount of vertical bite opening of the mandible. The StL, SpL, PT and AT played an important role in functional reconstruction of mandible by Herbst. All five group of bite reconstruction (3-7 mm advancement, 4-2 mm vertical bite opening of the mandible) designed by this study can be selected in clinic according to the patient's capability of adaptation, the extent of malocclusion and the potential and direction of growth.

Estimation of optimal nasotracheal tube depth in adult patients.

PubMed

Ji, Sung-Mi

2017-12-01

The aim of this study was to estimate the optimal depth of nasotracheal tube placement. We enrolled 110 patients scheduled to undergo oral and maxillofacial surgery, requiring nasotracheal intubation. After intubation, the depth of tube insertion was measured. The neck circumference and distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch were measured. To estimate optimal tube depth, correlation and regression analyses were performed using clinical and anthropometric parameters. The mean tube depth was 28.9 ± 1.3 cm in men (n = 62), and 26.6 ± 1.5 cm in women (n = 48). Tube depth significantly correlated with height (r = 0.735, P < 0.001). Distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch correlated with depth of the endotracheal tube (r = 0.363, r = 0.362, and r = 0.546, P < 0.05). The tube depth also correlated with the sum of these distances (r = 0.646, P < 0.001). We devised the following formula for estimating tube depth: 19.856 + 0.267 × sum of the three distances (R 2 = 0.432, P < 0.001). The optimal tube depth for nasotracheally intubated adult patients correlated with height and sum of the distances from nares to tragus, tragus to angle of the mandible, and angle of the mandible to sternal notch. The proposed equation would be a useful guide to determine optimal nasotracheal tube placement.

Adamantinoma — Histogenesis and Differentiation from the Periodontal Fibromatous Epulis and Squamous Cell Carcinoma

PubMed Central

Mills, J. H. L.; Lewis, R. J.

1981-01-01

Six cases of oral adamantinoma, four in dogs, two in cats, are described. This is a rare tumor which arises from vestigial layers of the dental laminae in the gingiva, particularly of the mandible. Care must be exercised in not confusing this locally aggressive lesion with the much more common squamous cell carcinoma. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9. PMID:7248887

Retrospective Study of 383 Cases of Fibro-Osseous Lesions of the Jaws.

PubMed

Kato, Camila de Nazaré Alves de Oliveira; Nunes, Laiz Fernandes Mendes; Chalub, Loliza Luiz Figueiredo Houri; Etges, Adriana; Silva, Tarcília Aparecida; Mesquita, Ricardo Alves

2018-05-10

The aims of this study were to describe the clinical and radiologic features of 383 fibro-osseous lesions (FOLs) from an oral pathology reference service in Brazil and to compare the findings with previous studies. The hypothesis of the study was that the most common type of FOL would differ from other investigations. We conducted a descriptive and retrospective study with review of the records of the clinical and biopsy services (1990 to 2015). All records of the patients included showed a definitive diagnosis of FOL. The primary outcome variable was the type of FOL, and the predictor variables were gender, age, ethnicity, location, and clinical and radiologic characteristics. Descriptive analyses and χ 2 tests were performed. The P value was set at .05. From the 27,998 records available, 383 showed FOLs, with 187 (48.8%) being cemento-osseous dysplasias (CODs), 103 (26.9%) being fibrous dysplasias (FDs), and 93 (24.3%) being ossifying fibromas (OFs). The mean age of the patients was 38.5 ± 17.5 years. CODs presented a predilection for female gender (n = 314, 82.0%), African descent (n = 134, 71.6%), and the mandible (n = 248, 64.6%). The most common radiologic feature was a mixed radiolucent-radiopaque image (n = 149, 51.7%). FDs and OFs were commonly diagnosed during the first and second decades of life (P < .001), whereas CODs were more frequently diagnosed beyond the third decade (P < .001). Secondary osteomyelitis was more significantly observed in CODs (P < .001) than in FDs and OFs. Swelling was more frequently reported for FDs and OFs than for CODs (P < .001). CODs were the most frequently observed FOLs in this Brazilian population. Female patients, patients of African descent, and patients with mandibular localization were most commonly affected by these conditions. The most common type of FOL differed from that in similar case reports or series from various geographic locations. It is believed that the data source (clinical and/or biopsy services) can directly influence the outcome. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

The role of the titanium functionally dynamic bridging plate for the treatment of the atrophic mandible fractures.

PubMed

Hachleitner, Johannes; Enzinger, Simon; Brandtner, Christian; Gaggl, Alexander

2014-07-01

The role of the titanium functionally dynamic bridging plate (TFDBP) in the fracture treatment of the severely atrophic mandible was assessed retrospectively. In 28 consecutive patients with fractures of a severely atrophic mandible fixation was carried out with TFDBPs. Twenty-one patients with 27 fractures were included in the study and then followed up for complications and the progress of fracture healing for 17 months postoperatively on average. There was only one case that required plate removal. All patients showed bone healing 3 months after surgery. The mental nerve sensation improved in 12 out of 23 fractures that had presented with nerve function disturbance. Every patient who had dentures prior to sustaining the fracture was able to return to denture wearing 3 weeks after surgery. No major complications occurred. A high proportion of bone healing with a low complication rate was observed with the use of TFDBPs in the treatment of severely atrophic mandible fractures. The TFDBP is an excellent alternative to conventional plating of the severely atrophic mandible. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Reduced somatosensory impairment by piezosurgery during orthognathic surgery of the mandible.

PubMed

Brockmeyer, Phillipp; Hahn, Wolfram; Fenge, Stefan; Moser, Norman; Schliephake, Henning; Gruber, Rudolf Matthias

2015-09-01

This clinical trial aimed to test the hypothesis that piezosurgery causes reduced nerval irritations and, thus, reduced somatosensory impairment when used in orthognathic surgery of the mandible. To this end, 37 consecutive patients with Angle Class II and III malocclusion were treated using bilateral sagittal split osteotomies (BSSO) of the mandible. In a split mouth design, randomized one side of the mandible was operated using a conventional saw, while a piezosurgery device was used on the contralateral side. In order to test the individual qualities of somatosensory function, quantitative sensory testings (QSTs) were performed 1 month, 6 months and 1 year after surgery. A comparison of the data using a two-way analysis of variance (ANOVA) revealed a significant reduction in postoperative impairment in warm detection threshold (WDT) (P = 0.046), a decreased dynamic mechanical allodynia (ALL) (P = 0.002) and a decreased vibration detection threshold (VDT) (P = 0.030) on the piezosurgery side of the mandible as opposed to the conventionally operated control side. In the remaining QSTs, minor deviations from the preoperative baseline conditions and a more rapid regression could be observed. Piezosurgery caused reduced somatosensory impairment and a faster recovery of somatosensory functions in the present investigation.

Changing the facial features of patients with Treacher Collins syndrome: protocol for 3-stage treatment of hard and soft tissue hypoplasia in the upper half of the face.

PubMed

Mitsukawa, Nobuyuki; Saiga, Atsuomi; Satoh, Kaneshige

2014-07-01

Treacher Collins syndrome is a disorder characterized by various congenital soft tissue anomalies involving hypoplasia of the zygoma, maxilla, and mandible. A variety of treatments have been reported to date. These treatments can be classified into 2 major types. The first type involves osteotomy for hard tissue such as the zygoma and mandible. The second type involves plastic surgery using bone grafting in the malar region and soft tissue repair of eyelid deformities. We devised a new treatment to comprehensively correct hard and soft tissue deformities in the upper half of the face of Treacher Collins patients. The aim was to "change facial features and make it difficult to tell that the patients have this disorder." This innovative treatment strategy consists of 3 stages: (1) placement of dermal fat graft from the lower eyelid to the malar subcutaneous area, (2) custom-made synthetic zygomatic bone grafting, and (3) Z-plasty flap transposition from the upper to the lower eyelid and superior repositioning and fixation of the lateral canthal tendon using a Mitek anchor system. This method was used on 4 patients with Treacher Collins syndrome who had moderate to severe hypoplasia of the zygomas and the lower eyelids. Facial features of these patients were markedly improved and very good results were obtained. There were no major complications intraoperatively or postoperatively in any of the patients during the series of treatments. In synthetic bone grafting in the second stage, the implant in some patients was in the way of the infraorbital nerve. Thus, the nerve was detached and then sutured under the microscope. Postoperatively, patients had almost full restoration of sensory nerve torpor within 5 to 6 months. We devised a 3-stage treatment to "change facial features" of patients with hypoplasia of the upper half of the face due to Treacher Collins syndrome. The treatment protocol provided a very effective way to treat deformities of the upper half of the face in patients with Treacher Collins syndrome.

Osteosclerotic bone dysplasia (melorheostosis) of the mandible.

PubMed

Kuttenberger, J J; Hardt, N; Gebbers, J-O; Hofer, B

2006-12-01

Melorheostosis is a linear bone dysplasia of unknown origin that may be associated with soft-tissue alterations. Although any part of the skeleton can be affected, this condition is rarely observed in the craniofacial region. Only seven cases of melorheostosis with craniofacial involvement have been reported and cranial manifestation only is even rarer. To the authors' knowledge, manifestation in the mandible only has not yet been documented. A patient with isolated melorheostosis of the mandible with characteristic symptomatic bone pain is presented. The clinical, radiological and histological findings are described and possible therapeutic options are discussed.

[Anatomical and radiological studies on additional mandible teeth anesthesia considering innervation variability].

PubMed

Tarasenko, S V; Dydykin, S S; Kuzin, A V

2013-01-01

The paper presents studies on nutritional foramina of the mandible. Some nutritional foramina located in the frontal mandibular region on the lingual surface and containing significant blood vessels and nerves are found to be more typical for teeth-bearing mandible. In retromolar area in case of third molars presence intraosseous canals were revealed leading to inferior alveolar nerve canal. One should consider intraligamental and lingual anesthesia by lower incisors extraction. Intraosseous anesthesia and retromolar area infiltration significantly increase anesthesia efficiency by third molar extraction.

Osteosarcoma of the mandible mimicking an odontogenic abscess: a case report and review of the literature.

PubMed

Bhadage, Chetan J; Vaishampayan, Sagar; Kolhe, Swapnil; Umarji, Hemant

2013-04-01

Inflammatory lesions, like periapical/odontogenic abscesses, are by far the most common pathologic condition of the jaws. Radiographically, these lesions commonly manifest as widening of periodontal ligament space, discontinuity of lamina dura and ill-defined periapical radiolucency. There are some rare disorders which could cause similar radiographic changes in the jaw bone. With careful scrutiny of periapical radiolucency, regular periodic follow-up radiographs and histo-pathologic examination, the periapical abscess or infection can be differentiated from rare fatal disorders. This paper highlights the need for vigilant examination of even the commonest, innocuous-appearing periapical changes which sometimes are produced by some rare fatal disorders.

Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles.

PubMed

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J; Lavine, Laura C; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters.

Developmental Link between Sex and Nutrition; doublesex Regulates Sex-Specific Mandible Growth via Juvenile Hormone Signaling in Stag Beetles

PubMed Central

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J.; Lavine, Laura C.; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters. PMID:24453990

Dual Pathology of Mandible

PubMed Central

Rajurkar, Suday G.; Deshpande, Mohan D.; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

2017-01-01

Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed. PMID:29264307

Dual Pathology of Mandible.

PubMed

Rajurkar, Suday G; Deshpande, Mohan D; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

2017-01-01

Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed.

A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana)

PubMed Central

Stansfield, Fiona J.

2015-01-01

The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These ‘Age Reference Lines’ were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70–75 years. Methods to aid in molar identification and the sexing of found jaws were also identified. PMID:25970428

Enamel-like apatite crown covering amorphous mineral in a crayfish mandible

PubMed Central

Bentov, Shmuel; Zaslansky, Paul; Al-Sawalmih, Ali; Masic, Admir; Fratzl, Peter; Sagi, Amir; Berman, Amir; Aichmayer, Barbara

2012-01-01

Carbonated hydroxyapatite is the mineral found in vertebrate bones and teeth, whereas invertebrates utilize calcium carbonate in their mineralized organs. In particular, stable amorphous calcium carbonate is found in many crustaceans. Here we report on an unusual, crystalline enamel-like apatite layer found in the mandibles of the arthropod Cherax quadricarinatus (freshwater crayfish). Despite their very different thermodynamic stabilities, amorphous calcium carbonate, amorphous calcium phosphate, calcite and fluorapatite coexist in well-defined functional layers in close proximity within the mandible. The softer amorphous minerals are found primarily in the bulk of the mandible whereas apatite, the harder and less soluble mineral, forms a wear-resistant, enamel-like coating of the molar tooth. Our findings suggest a unique case of convergent evolution, where similar functional challenges of mastication led to independent developments of structurally and mechanically similar, apatite-based layers in the teeth of genetically remote phyla: vertebrates and crustaceans. PMID:22588301

Treatment of a large radicular cyst-enucleation or decompression?

PubMed

Matijević, Stevo; Jovivić, Bojan; Bubalo, Marija; Dukić, Smiljka; Cutović, Tatjana

2015-04-01

Radicular cysts treatment involves surgical approach, more or less aggressive. However, treatment of large cystic lesions, including radicular cysts, causes some of dilemmas concerning the choice of the surgical method, especially the degree of radicalism. We presented a 65-year-old male patient with large radicular cyst in the mandible. A large elliptical multilocular radiolucency, located in the left side of the mandible, being in close vicinity to the mandibular canal, was registered at the orthopantomographic radiography. There was a risk of pathological fracture of the mandible. However, the cyst was completely removed by enucleation without intraoperative and postoperative complications. The presented case support the opinion that careful enucleation of large mandibular cysts may be done without complications, such as damages of surrounding anatomical structures or mandibular fracture. The authors indicate reasons for strong support of the undertaken surgical approach of treating large radicular cysts in the mandible.

Morphological Integration of the Modern Human Mandible during Ontogeny

PubMed Central

Polanski, Joshua M.

2011-01-01

Craniofacial integration is prevalent in anatomical modernity research. Little investigation has been done on mandibular integration. Integration patterns were quantified in a longitudinal modern human sample of mandibles. This integration pattern is one of modularization between the alveolar and muscle attachment regions, but with age-specific differences. The ascending ramus and nonalveolar portions of the corpus remain integrated throughout ontogeny. The alveolar region is dynamic, becoming modularized according to the needs of the mandible at a particular developmental stage. Early in ontogeny, this modularity reflects the need for space for the developing dentition; later, modularity is more reflective of mastication. The overall pattern of modern human mandibular integration follows the integration pattern seen in other mammals, including chimpanzees. Given the differences in craniofacial integration patterns between humans and chimpanzees, but the similarities in mandibular integration, it is likely that the mandible has played the more passive role in hominin skull evolution. PMID:21716741

A Complex Facial Trauma Case with Multiple Mandibular Fractures and Dentoalveolar Injuries

PubMed Central

Zorlu, Sevgi; Cankaya, Abdulkadir Burak; Aktoren, Oya; Gencay, Koray

2015-01-01

The principles of management of mandibular fractures differ in children when compared to adults and depend on the specific age-related status of the growing mandible and the developing dentition. This paper presents a case report with a complex facial trauma affecting the mandibular body and condyle region and dentoalveolar complex. Clinical examination revealed soft tissue injuries, limited mouth opening, lateral deviation of the mandible, an avulsed incisor, a subluxated incisor, and a fractured crown. CBCT examination revealed a nondisplaced fracture and an oblique greenstick fracture of the mandibular body and unilateral fracture of the condyle. Closed reduction technique was chosen to manage fractures of the mandible. Favorable healing outcomes on multiple fractures of the mandible throughout the 6-year follow-up period proved the success of the conservative treatment. This case report is important since it presents a variety of pathological sequelae to trauma within one case. PMID:26339511

[3-D finite element modeling of internal fixation of mandibular mental fracture and the design of boundary constraints].

PubMed

Luo, Xiaohui; Wang, Hang; Fan, Yubo

2007-04-01

This study was aimed to develop a 3-D finite element (3-D FE) model of the mental fractured mandible and design the boundary constrains. The CT images from a health volunteer were used as the original information and put into ANSYS program to build a 3-D FE model. The model of the miniplate and screw which were used for the internal fixation was established by Pro/E. The boundary constrains of different muscle loadings were used to simulate the 3 functional conditions of the mandible. A 3-D FE model of mental fractured mandible under the miniplate-screw internal fixation system was constructed. And by the boundary constraints, the 3 biting conditions were simulated and the model could serve as a foundation on which to analyze the biomechanical behavior of the fractured mandible.

Bilateral fractures of the coronoid processes: differential diagnosis of intra-oral gunshot trauma and scavenging using a sheep crania model.

PubMed

Puskas, Cathy M

2003-11-01

Approximately half of the skeleton of an adult male (minus the cranium) was found in a forested part of Greater Vancouver, Canada, in August 2000 by the Royal Canadian Mounted Police (RCMP). Authorities ruled the death as suicide. The only compelling signs of perimortem trauma were symmetrically fractured coronoid processes of the mandible, which can be attributed to a gunshot in the mouth. However, the remains had also been scavenged by canids, raising a problem in differential diagnosis. Could canid scavenging produce bilateral fracturing of the mandible indistinguishable from gunshot wounds to the mouth? We found that canid scavengers could not mimic the type of damage to the mandible caused by intra-oral gunshot wounding using a sheep model (n = 20). Bilateral fracturing of the coronoid processes was found to be characteristic of intra-oral gunshot wounding, while canid scavengers typically ignore this region of the mandible.

Sexual dimorphism of the mandible in a contemporary Chinese Han population.

PubMed

Dong, Hongmei; Deng, Mohong; Wang, WenPeng; Zhang, Ji; Mu, Jiao; Zhu, Guanghui

2015-10-01

A present limitation of forensic anthropology practice in China is the lack of population-specific criteria on contemporary human skeletons. In this study, a sample of 203 maxillofacial Cone beam computed tomography (CBCT) images, including 96 male and 107 female cases (20-65 years old), was analyzed to explore mandible sexual dimorphism in a population of contemporary adult Han Chinese to investigate the potential use of the mandible as sex indicator. A three-dimensional image from mandible CBCT scans was reconstructed using the SimPlant Pro 11.40 software. Nine linear and two angular parameters were measured. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop the mathematics models for sex determination. All of the linear measurements studied and one angular measurement were found to be sexually dimorphic, with the maximum mandibular length and bi-condylar breadth being the most dimorphic by univariate DFA and LRA respectively. The cross-validated sex allocation accuracies on multivariate were ranged from 84.2% (direct DFA), 83.5% (direct LRA), 83.3% (stepwise DFA) to 80.5% (stepwise LRA). In general, multivariate DFA yielded a higher accuracy and LRA obtained a lower sex bias, and therefore both DFA and LRA had their own advantages for sex determination by the mandible in this sample. These results suggest that the mandible expresses sexual dimorphism in the contemporary adult Han Chinese population, indicating an excellent sexual discriminatory ability. Cone beam computed tomography scanning can be used as alternative source for contemporary osteometric techniques. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible.

PubMed

Shadwick, Robert E; Goldbogen, Jeremy A; Pyenson, Nicholas D; Whale, James C A

2017-11-01

The mandibles of rorqual whales are highly modified to support loads associated with lunge-feeding, a dynamic filter feeding mechanism that is characterized by rapid changes in gape angle and acceleration. Although these structures are the largest ossified elements in animals and an important part of the rorqual engulfment apparatus, details of internal structure are limited and no direct measurements of mechanical properties exist. Likewise, the forces that are sustained by the mandibles are unknown. Here we report on the structure and mechanical behavior of the mandible of an adult fin whale. A series of transverse sections were cut at locations along the entire length of a 3.6-m left mandible recovered post-mortem from a 16-m fin whale, and CT scanned to make density maps. Cored samples 6-8 mm in diameter were tested in compression to determine the Young's modulus and strength. In addition, wet density, dry density and mineral density were measured. Dense cortical bone occupies only a relatively narrow peripheral layer while much less dense and oil-filled trabecular bone occupies the rest. Mineral density of both types is strongly correlated with dry density and CT Hounsfield units. Compressive strength is strongly correlated with Young's modulus, while strength and stiffness are both correlated with mineral density. It appears that the superficial compact layer is the main load bearing element, and that the mandible is reinforced against dorso-vental flexion that would occur during the peak loads while feeding. Anat Rec, 300:1953-1962, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

215 mandible fractures in 120 children: demographics, treatment, outcomes, and early growth data.

PubMed

Smith, Darren M; Bykowski, Michael R; Cray, James J; Naran, Sanjay; Rottgers, S Alex; Shakir, Sameer; Vecchione, Lisa; Schuster, Lindsay; Losee, Joseph E

2013-06-01

Optimal management of pediatric mandible fractures demands that the practitioner balance reduction and fixation with preservation of growth potential and function. The ideal synthesis of these goals has not yet been defined. The authors catalogue their experience with pediatric mandible fractures at a major pediatric teaching hospital with reference to demographics, injury type, treatment, and outcomes to inform future management of these injuries. Demographics, management, and outcomes of pediatric mandible fractures presenting over 10 years at a pediatric trauma center were assessed. Cephalometric analysis was conducted. Relationships among demographics, fracture type, management, outcomes, and growth were explored. Two hundred fifteen mandible fractures in 120 patients younger than 18 years were analyzed (average follow-up, 19.5 months). The condylar head and neck were fractured most frequently. Operative management was significantly more likely for children older than 12 years (p<0.05). Operative management and multiple fractures were significantly associated with a higher rate of adverse outcomes (p<0.05), but no adverse outcomes were considered to significantly affect mandibular function by patient or surgeon. No significant growth differences existed on cephalometric analysis between our cohort and age- and sex-matched controls (p>0.05). This study reports the demographics, treatment, and early follow-up of a sizable cohort of pediatric mandible fractures. Management principles for these injuries are outlined. Although definitive recommendations must be withheld until longer follow-up is available, the data presented here show that the treatment protocols used at the authors' center have yielded largely uncompromised mandibular function and growth thus far.

Fast and Powerful: Biomechanics and Bite Forces of the Mandibles in the American Cockroach Periplaneta americana

PubMed Central

Weihmann, Tom; Reinhardt, Lars; Weißing, Kevin; Siebert, Tobias; Wipfler, Benjamin

2015-01-01

Knowing the functionality and capabilities of masticatory apparatuses is essential for the ecological classification of jawed organisms. Nevertheless insects, especially with their outstanding high species number providing an overwhelming morphological diversity, are notoriously underexplored with respect to maximum bite forces and their dependency on the mandible opening angles. Aiming for a general understanding of insect biting, we examined the generalist feeding cockroach Periplaneta americana, characterized by its primitive chewing mouth parts. We measured active isometric bite forces and passive forces caused by joint resistance over the entire mandibular range with a custom-built 2D force transducer. The opening angle of the mandibles was quantified by using a video system. With respect to the effective mechanical advantage of the mandibles and the cross-section areas, we calculated the forces exerted by the mandible closer muscles and the corresponding muscle stress values. Comparisons with the scarce data available revealed close similarities of the cockroaches’ mandible closer stress values (58 N/cm2) to that of smaller specialist carnivorous ground beetles, but strikingly higher values than in larger stag beetles. In contrast to available datasets our results imply the activity of faster and slower muscle fibres, with the latter becoming active only when the animals chew on tough material which requires repetitive, hard biting. Under such circumstances the coactivity of fast and slow fibres provides a force boost which is not available during short-term activities, since long latencies prevent a specific effective employment of the slow fibres in this case. PMID:26559671

Etiology, distribution, treatment modalities and complications of maxillofacial fractures

PubMed Central

Pham-Dang, Nathalie; Barthélémy, Isabelle; Orliaguet, Thierry; Artola, Alain; Mondié, Jean M.

2014-01-01

Purpose: This study evaluated the trends and factors associated with maxillofacial fractures treated from 1997 to 2007 in the Oral and Maxillofacial Surgery Department of the Clermont-Ferrand University Hospital. Material and Methods: This study included 364 patients of which 82% were men and 45%, 20-29-years old. The etiology, anatomical distribution, treatment modality and complications of maxillofacial fractures were examined. Results: Overall, interpersonal violence, traffic accidents and falls were the most common mechanisms of injury. There was a decreasing trend in traffic accidents and increasing one in falls as a cause of fracture over the 11-years period of this study. Young male patients were preferentially victim of interpersonal violence and traffic accidents, while middle-aged ones were of falls and work-related accidents. Middle-aged female patients were preferentially victim of traffic accidents and interpersonal violence, while older ones were of falls. And the number of fractures per patient varied according to the mechanism of injury: low after work-related accidents and high after traffic accidents. About two-third of fractures involved the mandible. Most of these mandibular fractures were treated by osteosynthesis with or without intermaxillary fixation, with the proportion of the latter increasing over time. There were very few postoperative infections and only in mandible. Conclusions: Maxillofacial fractures predominantly occur in young men, due to interpersonal violence. There is nevertheless an increasing trend in falls as a cause of fracture, especially in female patients, consistent with the increasing trend in presentation of older people. Most maxillofacial fractures involve the mandible and there is an increasing trend in treating these fractures by osteosynthesis without intermaxillary fixation. Antibiotic prophylaxis associated with dental hygiene care can be indicated to prevent postoperative infections. Key words:Maxillofacial fractures, Epidemiology, Trends, Influencing factors, Fall, Age, Gender, Antibiotic prophylaxis. PMID:24316696

Mechanical design optimization of bioabsorbable fixation devices for bone fractures.

PubMed

Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret

2009-03-01

Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

Maxillomandibular Fixation by Plastic Surgeons: Cost Analysis and Utilization of Resources.

PubMed

Farber, Scott J; Snyder-Warwick, Alison K; Skolnick, Gary B; Woo, Albert S; Patel, Kamlesh B

2016-09-01

Maxillomandibular fixation (MMF) can be performed using various techniques. Two common approaches used are arch bars and bone screws. Arch bars are the gold standard and inexpensive, but often require increased procedure time. Bone screws with wire fixation is a popular alternative, but more expensive than arch bars. The differences in costs of care, complications, and operative times between these 2 techniques are analyzed. A chart review was conducted on patients treated over the last 12 years at our institution. Forty-four patients with CPT code 21453 (closed reduction of mandible fracture with interdental fixation) with an isolated mandible fracture were used in our data collection. The operating room (OR) costs, procedure duration, and complications for these patients were analyzed. Operative times were significantly shorter for patients treated with bone screws (P < 0.002). The costs for one trip to the OR for either method of fixation did not show any significant differences (P < 0.840). More patients with arch bar fixation (62%) required a second trip to the OR for removal in comparison to those with screw fixation (31%) (P < 0.068). This additional trip to the OR added significant cost. There were no differences in patient complications between these 2 fixation techniques. The MMF with bone screws represents an attractive alternative to fixation with arch bars in appropriate scenarios. Screw fixation offers reduced costs, fewer trips to the OR, and decreased operative duration without a difference in complications. Cost savings were noted most significantly in a decreased need for secondary procedures in patients who were treated with MMF screws. Screw fixation offers potential for reducing the costs of care in treating patients with minimally displaced or favorable mandible fractures.

Keratinizing odontogenic cysts with a spectrum of verrucoid morphology: investigation of a potential role of human papillomavirus.

PubMed

Lalla, Kalpesh; Mahomed, Farzana; Meer, Shabnum

2016-11-01

The role of human papillomavirus (HPV) in keratinizing odontogenic cysts (OC) has only rarely been studied. We describe the clinicopathologic findings in a series of OCs that had unusual keratinization patterns and were investigated for a possible HPV etiology. Tissue samples from 29 patients with keratinizing OCs were studied for light microscopic features suggestive of HPV infection and by an HPV DNA polymerase chain reaction assay. The mean age at presentation was 31.1 years; 79.3% of the OCs occurred in the mandible and 46.4% were associated with an impacted tooth. The phenotypic characteristics koilocytes, hypergranulosis, and a verrucous pattern of the cyst-lining epithelium were observed in 69%, 62.1%, and 17.2% of cases, respectively. These histomorphologic features did not, however, correlate with HPV infection. HPV does not appear to play a role in keratinizing OCs and is not responsible for the wart-like histomorphologic features that may be seen in these lesions. Copyright © 2016 Elsevier Inc. All rights reserved.

Appraisal of jaw swellings in a Nigerian tertiary healthcare facility.

PubMed

Lasisi, Taye J; Adisa, Akinyele O; Olusanya, Adeola A

2013-02-01

The mandible and maxilla can be the site of myriads of lesions that may be categorized as neoplastic, cystic, reactive and infective or inflammatory. Literature reviewing jaw swellings in an amalgamated fashion are uncommon, probably because aetiologies for these swellings are varied. However, to appreciate their relative relationship, it is essential to evaluate the clinico-pathologic profile of jaw swellings. The aim of this appraisal is to describe the array of jaw swellings seen at our hospital from 1990 to 2011, to serve as a reference database. Biopsy records of all histologically diagnosed cases of jaw swellings seen at the department of Oral Pathology, University College Hospital between January 1990 and December 2011 were retrieved, coded and inputted into SPSS version 20. Data on prevalence, age, sex, site and histological diagnosis were analysed descriptively for each category of jaw swellings. All patients below 16 years were regarded as children. A total of 638 jaw swellings were recorded in the 22-year study period. The Non Odontogenic Tumours (NOT) were the commonest, accounting for 46.2% of all jaw swellings. Odontogenic Tumours (OT) formed 45% of all adult jaw swelling while it formed 25.2% in children and adolescents. Ameloblastoma was the commonest while the most common NOT was ossifying fibroma (OF). Chronic osteomyelitis of the jaws was about 6 times commoner in adult females than males and mostly involved the mandible. The most common malignant jaw swelling was Burkitts' lymphoma (BL) that was about 7 times more in children than adults. Osteogenic sarcoma was the most common malignancy in adults. Jaw swellings are extensively varied in types and pattern of occurrence. This study has categorized jaw swellings in a simple but comprehensive fashion to allow for easy referencing in local and international data acquisition and epidemiological comparison. Key words:Jaw swellings, odontogenic, Nigeria.

Different Surgical Approaches for Multiple Fractured Atrophic Mandibles

PubMed Central

Pereira, Felipe Ladeira; Gealh, Walter Cristiano; Barbosa, Carlos Eduardo Braga; Filho, Liogi Iwaki

2011-01-01

Atrophic edentulous mandible fractures in geriatric patients have low incidence but present several biological and biomechanical peculiarities that produce a nonunion rate of around 20%. Surgical extraoral approaches for internal fixation of these fractures can be transcervical or by one or two submandibular incisions. Two patients sustaining multiple fractures in atrophic edentulous mandible are presented: the first patient was 72-years-old, treated by two submandibular incisions, and the second was 81-years-old, treated by transcervical approach. We discuss the advantages and drawbacks of each approach and their indications according to the Luhr et al (1996) atrophy index. PMID:22379503

Coexistent Superscan and Lincoln Sign on Bone Scintigraphy.

PubMed

Kulkarni, Mukta; Soni, Atul; Shetkar, Shubhangi; Amer, Momin; Mulavekar, Amruta; Joshi, Prathamesh

2017-08-01

A 70-year-old man underwent Tc-methylene diphosphonate scintigraphy for staging of adenocarcinoma prostate. Scintigraphy revealed diffuse increased tracer uptake in skeletal system along with faint renal visualization, a pattern compatible with metastatic superscan. The scintigraphy also revealed increased radiotracer uptake in the body of the mandible-Lincoln sign or black beard sign. Radiological imaging revealed sclerotic lesions throughout the skeleton including the mandible, confirming widespread skeletal metastases. Lincoln sign is previously described in monostotic Paget disease of the mandible and in contiguous spread of oral malignancy. We describe this pattern in distant metastatic involvement from carcinoma prostate with coexistent superscan pattern.

[A new method of fabricating photoelastic model by rapid prototyping].

PubMed

Fan, Li; Huang, Qing-feng; Zhang, Fu-qiang; Xia, Yin-pei

2011-10-01

To explore a novel method of fabricating the photoelastic model using rapid prototyping technique. A mandible model was made by rapid prototyping with computerized three-dimensional reconstruction, then the photoelastic model with teeth was fabricated by traditional impression duplicating and mould casting. The photoelastic model of mandible with teeth, which was fabricated indirectly by rapid prototyping, was very similar to the prototype in geometry and physical parameters. The model was of high optical sensibility and met the experimental requirements. Photoelastic model of mandible with teeth indirectly fabricated by rapid prototyping meets the photoelastic experimental requirements well.

Relationship between the cranial base and the mandible in artificially deformed skulls.

PubMed

Ferros, I; Mora, M J; Obeso, I F; Jimenez, P; Martinez-Insua, A

2016-11-01

There is controversy regarding the relationship between mandibular position and alterations of the cranial base that provoke a more anterior location of the glenoid fossa. Artificially deformed skulls display marked alterations of the cranial base. This study evaluates mandibular changes as function of the morphology of the cranial base in these skulls. A geometric morphometric study was performed on lateral cephalometric X-rays of three groups of skulls: 32 with anteroposterior deformity, 17 with circumferential deformity and 39 with no apparent deformity. In artificially deformed skulls, the cranial base was deformed causing the mandibular condyle to be in a more anterior position. There was a complete remodelling of the mandible involving narrowing and elongation of the mandibular ramus, rotation of the corpus of the mandible and increased vertical height of the symphysis. Forward displacement did not occur. Integration between mandible and cranial base is not altered by deformation of the skull. Deformity of the cranial vault exerts an influence on the mandible, supporting the theory of modular units in complete integration. This also supports the theory that mandibular prognathism is a multifactorial result and not a direct effect of displacement of the cranial base. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

PubMed

De Santis, Roberto; Gloria, Antonio; Russo, Teresa; D'Amora, Ugo; Varriale, Angelo; Veltri, Mario; Balleri, Piero; Mollica, Francesco; Riccitiello, Francesco; Ambrosio, Luigi

2014-12-18

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Additive manufacturing for microvascular reconstruction of the mandible in 20 patients.

PubMed

Lethaus, Bernd; Poort, Lucas; Böckmann, Roland; Smeets, Ralf; Tolba, Rene; Kessler, Peter

2012-01-01

The aim of this study was to evaluate the use of model mandibles made preoperatively by additive manufacturing, which were used to prebend reconstruction plates prior to mandibular resection and reconstruction with microvascular bony flaps. Computer Tomography (CT) or Cone Beam Tomography (CBT) scans acquired preoperatively were used to obtain DICOM data sets to produce a model of the mandible using rapid prototyping. This model was used as a template to prebend and then sterilize a 2.3 or 2.7 reconstruction plate, which was used to reconstruct the mandible with a microvascular bony flap. This technique was used in 20 consecutive patients who required mandibular resection and reconstruction because of a tumour or osteoradionecrosis. The prebent plate was used in all patients intraoperatively without the need for any further bending. The average time to bend a plate on a nonsterile model was 0.42 h (range 0.25-0.68 h). This is felt to represent the minimum amount of time saved during the operation. Additive manufacture of the mandible prior to resection and reconstruction with a microvascular flap is a useful technique which reduces the operating time. Copyright © 2011 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Effect of piezopuncture on tooth movement and bone remodeling in dogs.

PubMed

Kim, Young-Seok; Kim, Su-Jung; Yoon, Hyun-Joo; Lee, Peter Joohak; Moon, Won; Park, Young-Guk

2013-07-01

The aim of the study was to elucidate whether a newly developed, minimally invasive procedure, piezopuncture, would be a logical modification for accelerating tooth movement in the maxilla and the mandible. Ten beagle dogs were divided into 2 groups. Traditional orthodontic tooth movement was performed in the control group. In the experimental group, a piezotome was used to make cortical punctures penetrating the gingiva around the moving tooth. Measurements were made in weeks 1 through 6. Tooth movement and bone apposition rates from the histomorphometric analyses were evaluated by independent t tests. The cumulative tooth movement distance was greater in the piezopuncture group than in the control group: 3.26-fold in the maxilla and 2.45-fold in the mandible. Piezopuncture significantly accelerated the tooth movements at all observation times, and the acceleration was greatest during the first 2 weeks for the maxilla and the second week for the mandible. Anabolic activity was also increased by piezopuncture: 2.55-fold in the maxilla and 2.35-fold in the mandible. Based on the different effects of piezopuncture on the maxilla and the mandible, the results of a clinical trial of piezopuncture with optimized protocols might give orthodontists a therapeutic benefit for reducing treatment duration. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Treatment of Brodie's Syndrome using parasymphyseal distraction through virtual surgical planning and RP assisted customized surgical osteotomy guide-A mock surgery report

NASA Astrophysics Data System (ADS)

Dahake, Sandeep; Kuthe, Abhaykumar; Mawale, Mahesh

2017-10-01

This paper aims to describe virtual surgical planning (VSP), computer aided design (CAD) and rapid prototyping (RP) systems for the preoperative planning of accurate treatment of the Brodie's Syndrome. 3D models of the patient's maxilla and mandible were separately generated based on computed tomography (CT) image data and fabricated using RP. During the customized surgical osteotmy guide (CSOG) design process, the correct position was identified and the geometry of the CSOG was generated based on affected mandible of the patient and fabricated by a RP technique. Surgical approach such as preoperative planning and simulation of surgical procedures was performed using advanced software. The VSP and RP assisted CSOG was used to avoid the damage of the adjacent teeth and neighboring healthy tissues. Finally the mock surgery was performed on the biomodel (i.e. diseased RP model) of mandible with reference to the normal maxilla using osteotomy bur with the help of CSOG. Using this CSOG the exact osteotomy of the mandible and the accurate placement of the distractor were obtained. It ultimately improved the accuracy of the surgery in context of the osteotomy and distraction. The time required in cutting the mandible and placement of the distractor was found comparatively less than the regular free hand surgery.

Malignant odontogenic tumors. A retrospective and collaborative study of seven cases.

PubMed

Mosqueda Taylor, Adalberto; Meneses García, Abelardo; Ruíz Godoy Rivera, Luz María; Suárez Roa, María de Lourdes; Luna Ortiz, Kuauhyama

2003-01-01

The frequency, clinico-pathologic features and outcome of malignant odontogenic tumors diagnosed according to the current WHO classification in three pathology services in Mexico City are presented. There were seven cases (5 male and 2 female patients), which represent less than 4% of all odontogenic tumors diagnosed in these services. There were six odontogenic carcinomas (two malignant ameloblastomas, two clear cell odontogenic carcinomas, one primary intraosseous carcinoma and one carcinoma arising in an odontogenic cyst) and one ameloblastic fibrosarcoma. Age ranged from 25 to 72 years (mean: 43.8). Clear cell odontogenic carcinomas occurred in the canine-premolar region, one in the maxilla and one in the mandible (one ia a man and one in a woman), while the remaining lesions affected the posterior region of the mandible, with a male predominance (4:1), which agrees with previously reported cases. Surgical resection was the treatment employed in all carcinomas, while the ameloblastic fibrosarcoma was treated with chemotherapy due to its large extension, but without favorable response. The patient with primary intraosseous carcinoma had submaxillary and cervical metastases and the neoplasm was the cause of death. In spite of their extremely low frequency, malignant odontogenic tumors are an important cause of extensive surgical procedures in the oral and maxillofacial region.

Adaptive bill morphology for enhanced tool manipulation in New Caledonian crows

PubMed Central

Matsui, Hiroshi; Hunt, Gavin R.; Oberhofer, Katja; Ogihara, Naomichi; McGowan, Kevin J.; Mithraratne, Kumar; Yamasaki, Takeshi; Gray, Russell D.; Izawa, Ei-Ichi

2016-01-01

Early increased sophistication of human tools is thought to be underpinned by adaptive morphology for efficient tool manipulation. Such adaptive specialisation is unknown in nonhuman primates but may have evolved in the New Caledonian crow, which has sophisticated tool manufacture. The straightness of its bill, for example, may be adaptive for enhanced visually-directed use of tools. Here, we examine in detail the shape and internal structure of the New Caledonian crow’s bill using Principal Components Analysis and Computed Tomography within a comparative framework. We found that the bill has a combination of interrelated shape and structural features unique within Corvus, and possibly birds generally. The upper mandible is relatively deep and short with a straight cutting edge, and the lower mandible is strengthened and upturned. These novel combined attributes would be functional for (i) counteracting the unique loading patterns acting on the bill when manipulating tools, (ii) a strong precision grip to hold tools securely, and (iii) enhanced visually-guided tool use. Our findings indicate that the New Caledonian crow’s innovative bill has been adapted for tool manipulation to at least some degree. Early increased sophistication of tools may require the co-evolution of morphology that provides improved manipulatory skills. PMID:26955788

Morphometric study on mandibular foramen and incidence of accessory mandibular foramen in mandibles of south Indian population and its clinical implications in inferior alveolar nerve block.

PubMed

Shalini, R; RaviVarman, C; Manoranjitham, R; Veeramuthu, M

2016-12-01

The mandibular foramen is a landmark for procedures like inferior alveolar nerve block, mandibular implant treatment, and mandibular osteotomies. The present study was aimed to identify the precise location of the mandibular foramen and the incidence of accessory mandibular foramen in dry adult mandibles of South Indian population. The distance of mandibular foramen from the anterior border of the ramus, posterior border of the ramus, mandibular notch, base of the mandible, third molar, and apex of retromolar trigone was measured with a vernier caliper in 204 mandibles. The mean distance of mandibular foramen from the anterior border of ramus of mandible was 17.11±2.74 mm on the right side and 17.41±3.05 mm on the left side, from posterior border was 10.47±2.11 mm on the right side and 9.68±2.03 mm on the left side, from mandibular notch was 21.74±2.74 mm on the right side and 21.92±3.33 mm on the left side, from the base of the ramus was 22.33±3.32 mm on the right side and 25.35±4.5 mm on the left side, from the third molar tooth was 22.84±3.94 mm on the right side and 23.23±4.21 mm on the left side, from the apex of retromolar trigone was 12.27±12.13 mm on the right side and 12.13±2.35 mm on the left side. Accessory mandibular foramen was present in 32.36% of mandibles. Knowledge of location mandibular foramen is useful to the maxillofacial surgeons, oncologists and radiologists.

Morphometric study on mandibular foramen and incidence of accessory mandibular foramen in mandibles of south Indian population and its clinical implications in inferior alveolar nerve block

PubMed Central

RaviVarman, C.; Manoranjitham, R.; Veeramuthu, M.

2016-01-01

The mandibular foramen is a landmark for procedures like inferior alveolar nerve block, mandibular implant treatment, and mandibular osteotomies. The present study was aimed to identify the precise location of the mandibular foramen and the incidence of accessory mandibular foramen in dry adult mandibles of South Indian population. The distance of mandibular foramen from the anterior border of the ramus, posterior border of the ramus, mandibular notch, base of the mandible, third molar, and apex of retromolar trigone was measured with a vernier caliper in 204 mandibles. The mean distance of mandibular foramen from the anterior border of ramus of mandible was 17.11±2.74 mm on the right side and 17.41±3.05 mm on the left side, from posterior border was 10.47±2.11 mm on the right side and 9.68±2.03 mm on the left side, from mandibular notch was 21.74±2.74 mm on the right side and 21.92±3.33 mm on the left side, from the base of the ramus was 22.33±3.32 mm on the right side and 25.35±4.5 mm on the left side, from the third molar tooth was 22.84±3.94 mm on the right side and 23.23±4.21 mm on the left side, from the apex of retromolar trigone was 12.27±12.13 mm on the right side and 12.13±2.35 mm on the left side. Accessory mandibular foramen was present in 32.36% of mandibles. Knowledge of location mandibular foramen is useful to the maxillofacial surgeons, oncologists and radiologists. PMID:28127498

Is there enough evidence so that mandible can be used as a tool for sex dimorphism? A systematic review.

PubMed

Hazari, Puja; Hazari, Rakesh S; Mishra, Sunil Kumar; Agrawal, Surendra; Yadav, Mukesh

2016-01-01

One of the most challenging tasks for forensic science is to identify the unknown human skeletal remains of deceased individuals. Study of sex by distinguishing the various morphological characteristics of bones is utmost important in forensic anthropology and for medico-legal assessment. The purpose of this article is to review the literature, to find if there is sufficient evidence to establish the use of mandible in sex identification. An electronic search was performed to identify suitable literature, using database of MEDLINE, PubMed, and EBSCOhost. Published articles in between January 2000 and April 2015 were searched. The main focus of search was on the various parameters of mandible studied in last 15 years for sex dimorphism. The focus was on the articles published on radiographic studies as well as on morphometric studies of dry mandible in which skeletal parameters were studied. The screening of titles and abstracts were done, suitable literature that fulfilled the inclusion criteria was selected for a full-text reading. The initial literature search resulted in 89 articles, out of which only 36 articles fulfilled the inclusion criteria and were included in this systematic review. Out of 16 radiographic studies, 14 showed statistically significant results that the adult mandible could be used with increased sensitivity and objectivity to identify both sex and population affinity compared to other standard analytical techniques, whereas two studies showed insignificant results. Out of 20 morphometric studies of dry mandible 15 studies showed a positive correlation between sex dimorphism and mandibular parameters and five studies did not show any positive correlations between the two.

Standardized Protocol for Virtual Surgical Plan and 3-Dimensional Surgical Template-Assisted Single-Stage Mandible Contour Surgery.

PubMed

Fu, Xi; Qiao, Jia; Girod, Sabine; Niu, Feng; Liu, Jian Feng; Lee, Gordon K; Gui, Lai

2017-09-01

Mandible contour surgery, including reduction gonioplasty and genioplasty, has become increasingly popular in East Asia. However, it is technically challenging and, hence, leads to a long learning curve and high complication rates and often needs secondary revisions. The increasing use of 3-dimensional (3D) technology makes accurate single-stage mandible contour surgery with minimum complication rates possible with a virtual surgical plan (VSP) and 3-D surgical templates. This study is to establish a standardized protocol for VSP and 3-D surgical templates-assisted mandible contour surgery and evaluate the accuracy of the protocol. In this study, we enrolled 20 patients for mandible contour surgery. Our protocol is to perform VSP based on 3-D computed tomography data. Then, design and 3-D print surgical templates based on preoperative VSP. The accuracy of the method was analyzed by 3-D comparison of VSP and postoperative results using detailed computer analysis. All patients had symmetric, natural osteotomy lines and satisfactory facial ratios in a single-stage operation. The average relative error of VSP and postoperative result on the entire skull was 0.41 ± 0.13 mm. The average new left gonial error was 0.43 ± 0.77 mm. The average new right gonial error was 0.45 ± 0.69 mm. The average pognion error was 0.79 ± 1.21 mm. Patients were very satisfied with the aesthetic results. Surgeons were very satisfied with the performance of surgical templates to facilitate the operation. Our standardized protocol of VSP and 3-D printed surgical templates-assisted single-stage mandible contour surgery results in accurate, safe, and predictable outcome in a single stage.

Sex determination from the mandibular ramus flexure of Koreans by discrimination function analysis using three-dimensional mandible models.

PubMed

Lin, Chenghe; Jiao, Benzheng; Liu, Shanshan; Guan, Feng; Chung, Nak-Eun; Han, Seung-Ho; Lee, U-Young

2014-03-01

It has been known that mandible ramus flexure is an important morphologic trait for sex determination. However, it will be unavailable when mandible is incomplete or fragmented. Therefore, the anthropometric analysis on incomplete or fragmented mandible becomes more important. The aim of this study is to investigate the sex-discriminant potential of mandible ramus flexure on the Korean three-dimensional (3D) mandible models with anthropometric analysis. The sample consists of 240 three dimensional mandibular models obtained from Korean population (M:F; 120:120, mean age 46.2 y), collected by The Catholic Institute for Applied Anatomy, The Catholic University of Korea. Anthropometric information about 11 metric was taken with Mimics, anthropometry libraries toolkit. These parameters were subjected to different discriminant function analyses using SPSS 17.0. Univariate analyses showed that the resubstitution accuracies for sex determination range from 50.4 to 77.1%. Mandibular flexure upper border (MFUB), maximum ramus vertical height (MRVH), and upper ramus vertical height (URVH) expressed the greatest dimorphism, 72.1 to 77.1%. Bivariate analyses indicated that the combination of MFUB and MRVH hold even higher resubstitution accuracy of 81.7%. Furthermore, the direct and stepwise discriminant analyses with the variables on the upper ramus above flexure could predict sex in 83.3 and 85.0%, respectively. When all variables of mandibular ramus flexure were input in stepwise discriminant analysis, the resubstitution accuracy arrived as high as 88.8%. Therefore, we concluded that the upper ramus above flexure hold the larger potentials than the mandibular ramus flexure itself to predict sexes, and that the equations in bivariate and multivariate analysis from our study will be helpful for sex determination on Korean population in forensic science and law. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Submandibular approach to the C2-3 disc level: microsurgical anatomy with clinical application.

PubMed

Russo, Antonino; Albanese, Erminia; Quiroga, Monica; Ulm, Arthur J

2009-04-01

Approaching the C2-3 disc level is challenging because of its location behind the mandible and the vital neurovascular structures overlying the area. The purpose of this study was to illustrate in a stepwise fashion the microsurgical anatomy of the submandibular approach to the C2-3 disc. Ten adult formalin-fixed cadaveric specimens (20 sides) were studied. Particular attention was paid to the structures limiting the exposure. The authors measured the distance between the inferior border of the mandible and the marginal mandibular branch of the facial nerve running inferior to the mandible, the distance between the horizontal segment of the hypoglossal nerve and the hyoid bone, and the distance between the horizontal segment of the hypoglossal nerve and the mandible. They compared the location of the superior laryngeal nerve with regard to the submandibular and the standard Smith-Robinson approaches. A clinical case illustrating the usefulness of the surgical technique in this region is presented. The mean distance between the inferior border of the mandible and the lowest point of the marginal mandibular branch of the facial nerve was 6.7 +/- 1.69 mm. The hypoglossal nerve's mean distance above the hyoid bone was 8.4 +/- 1.78 mm and below the mandible was 19.6 +/- 6.39 mm. The internal branch of the superior laryngeal nerve, with respect to the cervical spine, always entered the thyrohyoid membrane just inferior to the C-3 vertebral body. The superior laryngeal nerve was found to be an impediment to approaching the C2-3 disc through the standard Smith-Robinson approach. The submandibular approach provides excellent exposure, with a perpendicular view of the C2-3 disc level. This approach is one of the options to be considered when dealing with high cervical pathologies.

Implant-based three-dimensional superimposition of the growing mandible in a rabbit model.

PubMed

Parton, Andrew L; Duncan, Warwick J; Oliveira, Marcelo E; Key, Oscar; Farella, Mauro

2016-10-01

The reliable assessment of craniofacial morphological changes during growth requires invariant regions for image registration. As these regions have not yet been identified in three dimensions, intra-osseous implants are required as fiducial markers for the reliable assessment of three-dimensional (3D) mandibular growth changes. The objective of this study was to develop an animal model for the assessment of the 3D morphological changes of the mandible during growth, using implants as fiducial markers. Titanium implants were placed in the body of the mandible of six New Zealand White rabbits. Cone beam computed tomography (CBCT) scans were taken 1-week following implant placement and after an additional 8-weeks of growth. Segmentations of CBCT images were exported into custom-made scripts, implant centroids were identified, implant stability during growth calculated, and the segmented mandibles were registered on the implant centroids. The buccal cortical bone of the body of the mandible was stable during growth and suitable for fiducial marker placement. Bilateral implants resulted in more accurate rigid registration of the growing rabbit mandible than only unilateral implants. 3D mandibular growth changes were visualised by means of semi-transparencies. This animal model appears to be feasible for the assessment of the 3D morphological changes occurring during mandibular growth. To the best of our knowledge this is the first time that the implant superimposition method has been combined with 3D imaging to accurately reveal mandibular growth changes. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

A novel 3D template for mandible and maxilla reconstruction: Rapid prototyping using stereolithography

PubMed Central

Kumta, Samir; Kumta, Monica; Jain, Leena; Purohit, Shrirang; Ummul, Rani

2015-01-01

Introduction: Replication of the exact three-dimensional (3D) structure of the maxilla and mandible is now a priority whilst attempting reconstruction of these bones to attain a complete functional and aesthetic rehabilitation. We hereby present the process of rapid prototyping using stereolithography to produce templates for modelling bone grafts and implants for maxilla/mandible reconstructions, its applications in tumour/trauma, and outcomes for primary and secondary reconstruction. Materials and Methods: Stereolithographic template-assisted reconstruction was used on 11 patients for the reconstruction of the mandible/maxilla primarily following tumour excision and secondarily for the realignment of post-traumatic malunited fractures or deformity corrections. Data obtained from the computed tomography (CT) scans with 1-mm resolution were converted into a computer-aided design (CAD) using the CT Digital Imaging and Communications in Medicine (DICOM) data. Once a CAD model was constructed, it was converted into a stereolithographic format and then processed by the rapid prototyping technology to produce the physical anatomical model using a resin. This resin model replicates the native mandible, which can be thus used off table as a guide for modelling the bone grafts. Discussion: This conversion of two-dimensional (2D) data from CT scan into 3D models is a very precise guide to shaping the bone grafts. Further, this CAD can reconstruct the defective half of the mandible using the mirror image principle, and the normal anatomical model can be created to aid secondary reconstructions. Conclusion: This novel approach allows a precise translation of the treatment plan directly to the surgical field. It is also an important teaching tool for implant moulding and fixation, and helps in patient counselling. PMID:26933279

A novel 3D template for mandible and maxilla reconstruction: Rapid prototyping using stereolithography.

PubMed

Kumta, Samir; Kumta, Monica; Jain, Leena; Purohit, Shrirang; Ummul, Rani

2015-01-01

Replication of the exact three-dimensional (3D) structure of the maxilla and mandible is now a priority whilst attempting reconstruction of these bones to attain a complete functional and aesthetic rehabilitation. We hereby present the process of rapid prototyping using stereolithography to produce templates for modelling bone grafts and implants for maxilla/mandible reconstructions, its applications in tumour/trauma, and outcomes for primary and secondary reconstruction. Stereolithographic template-assisted reconstruction was used on 11 patients for the reconstruction of the mandible/maxilla primarily following tumour excision and secondarily for the realignment of post-traumatic malunited fractures or deformity corrections. Data obtained from the computed tomography (CT) scans with 1-mm resolution were converted into a computer-aided design (CAD) using the CT Digital Imaging and Communications in Medicine (DICOM) data. Once a CAD model was constructed, it was converted into a stereolithographic format and then processed by the rapid prototyping technology to produce the physical anatomical model using a resin. This resin model replicates the native mandible, which can be thus used off table as a guide for modelling the bone grafts. This conversion of two-dimensional (2D) data from CT scan into 3D models is a very precise guide to shaping the bone grafts. Further, this CAD can reconstruct the defective half of the mandible using the mirror image principle, and the normal anatomical model can be created to aid secondary reconstructions. This novel approach allows a precise translation of the treatment plan directly to the surgical field. It is also an important teaching tool for implant moulding and fixation, and helps in patient counselling.

Mechanical mandible competence in rats with nutritional growth retardation.

PubMed

Lezón, Christian Esteban; Pintos, Patricia Mabel; Bozzini, Clarisa; Romero, Alan Agüero; Casavalle, Patricia; Friedman, Silvia María; Boyer, Patricia Mónica

2017-08-01

In order to provide a better understanding of the sympathetic nervous system as a negative regulator of bone status, the aim of the study was to establish the biomechanical mandible response to different doses of a β-adrenergic antagonist such as propranolol (P) in a stress-induced food restriction model of growth retardation. Rats were assigned to eight groups: Control (C), C+P3.5 (CP3.5), C+P7 (CP7), C+P14 (CP14), NGR, NGR+P3.5 (NGRP3.5), NGR+P7 (NGRP7) and NGR+P14 (NGRP14). C, CP3.5, CP7 and CP14 rats were freely fed with the standard diet. NGR, NGRP3.5, NGRP7 and NGRP14 rats received, for 4 weeks (W4), 80% of the amount of controls food consumed. Propranolol 3.5, 7 and 14mg/kg/day was injected ip 5days per week in CP3.5 and NGRP3.5, CP7 and NGRP7, CP14 and NGRP14, respectively. At W4, zoometry, mandible morphometry, static histomorphometric and biomechanical competence were performed. A dose of Propranolol 7mg/kg/day induced interradicular bone volume accretion reaching a mandible stiffness according to chronological age. These findings evidenced that sympathetic nervous system activity is a negative regulator of mandible mechanical competence in the nutritional growth retardation model. Propranolol 7mg/kg/day, under the regimen usage, seems to be appropriate to blockade SNS activity on mandible mechanical performance in NGR rats, probably associated to an effect on bone mechanostat system ability to detect disuse mode as an error. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonextraction and nonsurgical treatment of an adult with skeletal Class II open bite with severe retrognathic mandible and temporomandibular disorders.

PubMed

Kondo, Etsuko

2007-01-01

The treatment of an adult patient with a skeletal Class II Division 1 malocclusion, retrognathic mandible with downward and backward rotation, anterior open bite, and temporomandibular disorders is presented. Treatment objectives included establishing a stable occlusion with normal respiration, eliminating temporomandibular disorder symptoms, and improving facial esthetics through nonextraction and nonsurgical treatment. The patient was a Japanese adult female, who had previously been advised to have orthognathic surgery. An expansion plate was used to reshape the maxillary dentoalveolar arch. Distalization of the maxillary arch and forward movement of the mandible were achieved by reduced excessive posterior occlusal vertical dimension, through uprighting and intruding the mandibular posterior teeth, and rotating the mandible slightly upward and forward. The functional occlusal plane was reconstructed by uprighting and intruding the mandibular posterior teeth with a full-bracket appliance, combined with a maxillary expansion plate and short Class II elastics. Myofunctional therapy and masticatory and cervical muscle training involved chewing gum exercises and neck-muscle massage. The excessive posterior vertical occlusal dimension was significantly reduced, creating a small clearance between the posterior maxilla and mandible. The occlusal interferences in the posterior area were eliminated by the expansion of the maxillary dentoalveolar arch. As a result, the mandible moved forward, creating a more favorable jaw relationship. Distal movement of the maxillary arch was also achieved. The functional occlusal plane was reconstructed and a normal overjet and overbite were created. Adequate tongue space for normal respiration was established during the early stage of treatment. A stable occlusion with adequate posterior support and anterior guidance was established in a treatment time of 25 months, without orthognathic surgery, extraction, or headgear; this result was maintained at more than 1 year 8 months posttreatment.

Specification of jaw identity by the Hand2 transcription factor

PubMed Central

Funato, Noriko; Kokubo, Hiroki; Nakamura, Masataka; Yanagisawa, Hiromi; Saga, Yumiko

2016-01-01

Acquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. The basic helix-loop-helix transcription factor Hand2, which is conserved among jawed vertebrates, is expressed in the neural crest in the mandibular process but not in the maxillary process of the first branchial arch. Here, we provide evidence that Hand2 is sufficient for upper jaw (maxilla)-to-mandible transformation by regulating the expression of homeobox transcription factors in mice. Altered Hand2 expression in the neural crest transformed the maxillae into mandibles with duplicated Meckel’s cartilage, which resulted in an absence of the secondary palate. In Hand2-overexpressing mutants, non-Hox homeobox transcription factors were dysregulated. These results suggest that Hand2 regulates mandibular development through downstream genes of Hand2 and is therefore a major determinant of jaw identity. Hand2 may have influenced the evolutionary acquisition of the mandible and secondary palate. PMID:27329940

[Registration technology for mandibular angle osteotomy based on augmented reality].

PubMed

Zhu, Ming; Chai, Gang; Zhang, Yan; Ma, Xiao-Fei; Yu, Zhe-Yuan; Zhu, Yi-Jia

2010-12-01

To establish an effective path to register the operative plan to the real model of mandible made by rapid prototyping (RP) technology. Computerize tomography (CT) was performed on 20 patients to create 3D images, and computer aided operation planning information can be merged with the 3D images. Then dental cast was used to fix the signal which can be recognized by the software. The dental cast was transformed to 3D data with a laser scanner and a programmer that run on a personal computer named Rapidform matching the dental cast and the mandible image to generate the virtual image. Then the registration was achieved by video monitoring system. By using this technology, the virtual image of mandible and the cutting planes both can overlay the real model of mandible made by RP. This study found an effective way for registration by using dental cast, and this way might be a powerful option for the registration of augmented reality. Supported by Program for Innovation Research Team of Shanghai Municipal Education Commission.

The Watinglo mandible: a second terminal Pleistocene Homo sapiens fossil from tropical Sahul with a test on existing models for the human settlement of the region.

PubMed

Bulbeck, D; O'Connor, S

2011-02-01

This paper analyses a fossil human mandible, dated to circa 10ka, from Watinglo rockshelter on the north coast of Papua New Guinea. The fossil is metrically and morphologically similar to male mandibles of recent Melanesians and Australian Aborigines. It is distinguished from Kow Swamp and Coobool Creek male mandibles (Murray Valley, terminal Pleistocene) by being smaller and having different shape characteristics, as well as smaller teeth and a slower rate of tooth wear. It pairs with the Liang Lemdubu female (Late Glacial Maximum, Aru Islands) in suggesting that the morphology of the terminal Pleistocene inhabitants of tropical Sahul was gracile compared to their contemporaries within the southern Murray drainage. An explanatory scenario for this morphological contrast is developed in the context of the Homo sapiens early fossil record, Australasian mtDNA evidence, terminal Pleistocene climatic variation, and the possibility of multiple entry points into Sahul. Copyright © 2010 Elsevier GmbH. All rights reserved.

Global human mandibular variation reflects differences in agricultural and hunter-gatherer subsistence strategies

PubMed Central

von Cramon-Taubadel, Noreen

2011-01-01

Variation in the masticatory behavior of hunter-gatherer and agricultural populations is hypothesized to be one of the major forces affecting the form of the human mandible. However, this has yet to be analyzed at a global level. Here, the relationship between global mandibular shape variation and subsistence economy is tested, while controlling for the potentially confounding effects of shared population history, geography, and climate. The results demonstrate that the mandible, in contrast to the cranium, significantly reflects subsistence strategy rather than neutral genetic patterns, with hunter-gatherers having consistently longer and narrower mandibles than agriculturalists. These results support notions that a decrease in masticatory stress among agriculturalists causes the mandible to grow and develop differently. This developmental argument also explains why there is often a mismatch between the size of the lower face and the dentition, which, in turn, leads to increased prevalence of dental crowding and malocclusions in modern postindustrial populations. Therefore, these results have important implications for our understanding of human masticatory adaptation. PMID:22106280

The position of the mental foramen in the north and south Indian populations.

PubMed

Srinivas, Naveen; Ramdurg, Praveenkumar; Puranik, Surekha R; Sali, Ketki; Ingaleshwar, Pramod

2017-05-01

The aim of the study was to determine and compare the position of the mental foramen MF in the north and south Indian populations using Panoramic radiographs. A total of 100 Panoramic radiographs were selected from the archives of PMNM Dental College and the Department of Oral Medicine and Radiology, of which 50 radiographs belonged to a north Indian population and 50 radiographs belonged to a local population of Bagalkot Karnataka. The position of the MF was classified into 6 positions depending on the relationship to the mandibular teeth. The distance from the superior border of the MF to the lower border of the mandible was also measured. The most common position of the MF was along the long axis of the second premolar in the north Indian population and in south Indian populations it was found to be between the first and second premolar. Descriptive analysis was used to compare the distance between the superior border of the mental foramen and the lower border of the mandible bilaterally. There was a significant difference in the position of the MF between the north and south Indian populations. Copyright © 2017 by Academy of Sciences and Arts of Bosnia and Herzegovina.

Comparative stress distribution of implant-retained mandibular ball-supported and bar-supported overlay dentures: a finite element analysis.

PubMed

Vafaei, Fariborz; Khoshhal, Masoumeh; Bayat-Movahed, Saeed; Ahangary, Ahmad Hassan; Firooz, Farnaz; Izady, Alireza; Rakhshan, Vahid

2011-08-01

Implant-retained mandibular ball-supported and bar-supported overlay dentures are the two most common treatment options for the edentulous mandible. The superior option in terms of strain distribution should be determined. The three-dimensional model of mandible (based on computerized tomography scan) and its overlying implant-retained bar-supported and ball-supported overlay dentures were simulated using SolidWorks, NURBS, and ANSYS Workbench. Loads A (60 N) and B (60 N) were exerted, respectively, in protrusive and laterotrusive motions, on second molar mesial, first molar mesial, and first premolar. The strain distribution patterns were assessed on (1) implant tissue, (2) first implant-bone, and (3) second implant-bone interfaces. Protrusive: Strain was mostly detected in the apical of the fixtures and least in the cervical when bar design was used. On the nonworking side, however, strain was higher in the cervical and lower in the apical compared with the working side implant. Laterotrusive: The strain values were closely similar in the two designs. It seems that both designs are acceptable in terms of stress distribution, although a superior pattern is associated with the application of bar design in protrusive motion.

A dental perspective on the taxonomic affinity of the Balanica mandible (BH-1).

PubMed

Skinner, Matthew M; de Vries, Dorien; Gunz, Philipp; Kupczik, Kornelius; Klassen, R Paul; Hublin, Jean-Jacques; Roksandic, Mirjana

2016-04-01

The Middle Pleistocene represents a period of critical importance in human evolution, marked by encephalisation and dental reduction, and increasing diversification of temporally and spatially distributed hominin lineages in Africa, Asia and Europe. New specimens, especially from areas less well represented in the fossil record, can inform the debate on morphological changes to the skeleton and teeth and the phylogenetic course of human evolution during this period. The mandible from the cave of Mala Balanica, Serbia has recently been re-dated to at least 400 ka, and its well-preserved dentition presents an excellent opportunity to characterize molar crown morphology at this time period, and re-examine claims for a lack of Neandertal affinities in the specimen. In this study we employ microtomography to image the internal structure of the mandibular molars (focusing on the morphology of the enamel-dentine junction, or EDJ) of the BH-1 specimen and a comparative sample (n = 141) of Homo erectus sensu lato, Homo neanderthalensis, Pleistocene Homo sapiens, and recent H. sapiens. We quantitatively assess EDJ morphology using 3D geometric morphometrics and examine the expression of discrete dental traits at the dentine surface. We also compare third molar enamel thickness in BH-1 to those of H. neanderthalensis and both Pleistocene and recent H. sapiens, and document previously unreported morphology of the BH-1 premolar and molar roots. Our results highlight the reliability of the EDJ surface for classifying hominin taxa, indicate a primitive dental morphology for BH-1 molars, and confirm a general lack of derived Neandertal features for the Balanica individual. The plesiomorphic character of BH-1 is consistent with several competing models of Middle Pleistocene hominin evolution and provides an important regional and temporal example for reconstructing morphological changes in the mandible and teeth during this time period. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of high temperature on different restorations in forensic identification: Dental samples and mandible

PubMed Central

Patidar, Kalpana A; Parwani, Rajkumar; Wanjari, Sangeeta

2010-01-01

Introduction: The forensic odontologist strives to utilize the charred human dentition throughout each stage of dental evaluation, and restorations are as unique as fingerprints and their radiographic morphology as well as the types of filling materials are often the main feature for identification. The knowledge of detecting residual restorative material and composition of unrecovered adjacent restoration is a valuable tool-mark in the presumptive identification of the dentition of a burned victim. Gold, silver amalgam, silicate restoration, and so on, have a different resistance to prolonged high temperature, therefore, the identification of burned bodies can be correlated with adequate qualities and quantities of the traces. Most of the dental examination relies heavily on the presence of the restoration as well as the relationship of one dental structure to another. This greatly narrows the research for the final identification that is based on postmortem data. Aim: The purpose of this study is to examine the resistance of teeth and different restorative materials, and the mandible, to variable temperature and duration, for the purpose of identification. Materials and Methods: The study was conducted on 72 extracted teeth which were divided into six goups of 12 teeth each based on the type of restorative material. (Group 1 - unrestored teeth, group 2 - teeth restored with Zn3(PO4)2, group 3 - with silver amalgam, group 4 with glass ionomer cement, group 5 - Ni-Cr-metal crown, group 6 - metal ceramic crown) and two specimens of the mandible. The effect of incineration at 400°C (5 mins, 15 mins, 30 mins) and 1100°C (15 mins) was studied. Results: Damage to the teeth subjected to variable temperatures and time can be categorized as intact (no damage), scorched (superficially parched and discolored), charred (reduced to carbon by incomplete combustion) and incinerated (burned to ashes). PMID:21189989

Morphology of the mouthparts of the spittlebug Philagra albinotata Uhler (Hemiptera: Cercopoidea: Aphrophoridae).

PubMed

Wang, Tingting; Pan, Liuxing; Zhang, Yalin; Dai, Wu

2015-03-01

Mouthparts associated with feeding behavior and feeding habits are important sensory and feeding structures in insects. To obtain a better understanding of feeding in Cercopoidea, the morphology of mouthparts of the spittlebug, Philagra albinotata Uhler was examined using scanning electron microscopy. The mouthparts of P. albinotata are of the typical piercing-sucking type found in Hemiptera, comprising a cone-shaped labrum, a tube-like, three-segmented labium with a deep groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets. The mandibles consist of a dorsal smooth region and a ventral serrate region near the apical half of the external convex region, and bear five nodules or teeth on the dorsal external convex region on the distal extremity; these are regarded as unique features that distinguish spittlebugs from other groups of Hemiptera. The externally smooth maxillary stylets, interlocked to form a larger food canal and a smaller salivary canal, are asymmetrical only in the internal position of longitudinal carinae and grooves. One dendritic canal is found in each maxilla and one in each mandible. Two types of sensilla trichodea, three types of sensilla basiconica and groups of multi-peg structures occur in different locations on the labium, specifically the labial tip with two lateral lobes divided into anterior sensory fields with ten small peg sensilla arranged in a 5+4+1 pattern and one big peg sensillum, and posterior sensory fields with four sensilla trichodea. Compared with those of previously studied Auchenorrhyncha, the mouthparts of P. albinotata may be distinguished by the shape of the mandibles, the multi-peg structures and a tooth between the salivary canal and the food canal on the extreme end of the stylets. The mouthpart morphology is illustrated using scanning electron micrographs, and the taxonomic and putative functional significance of the different structures is briefly discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Longitudinal study of relative growth rates of the maxilla and the mandible according to quantitative cervical vertebral maturation.

PubMed

Chen, Lili; Liu, Jiarong; Xu, Tianmin; Lin, Jiuxiang

2010-06-01

The purpose of this study was to investigate the relative growth rates (RGR) of the maxilla and the mandible according to quantitative cervical vertebral maturation (QCVM) of adolescents with normal occlusion. Mixed longitudinal data were used. The sample included 87 adolescents (32 boys, 55 girls) from 8 to 18 years of age with normal occlusion, selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year for 6 consecutive years. The growth magnitude (GM) and RGR of the maxilla and the mandible were measured and analyzed. GM and RGR were not always consistent, because subjects had different periods of time between the QCVM stages. GM was not as reliable as RGR. RGR had no significant sex differences in the maxilla and the mandible, in spite of different decelerating curves. However, statistically significant sex differences were found in the GM of mandibular measurements. The greatest growth potentials were not synchronized between the maxilla and the mandible. For both sexes, the greatest RGR of maxillary length and height was in QCVM stage I; then, deceleration occurred. The greatest RGR of mandibular length and height was in QCVM stage II, and the next largest was in QCVM stage I. Understanding the RGR can provide references for orthodontic treatment and orthognathic surgery. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

The effect of fluoridation and its discontinuation on fluoride profiles in the alveolar bone of rat.

PubMed

Ohmi, Kyohei; Nakagaki, Haruo; Tsuboi, Shinji; Okumura, Akihiro; Sugiyama, Tomoko; Thuy, Tran Thu; Robinson, Colin

2005-10-01

We investigated the effect of fluoridation and its discontinuation on fluoride content in the alveolar portion of the mandible in rats. Drinking water with three different fluoride contents (0, 50, 100 ppmF) was given to rats for three different periods (4, 13 and 25 weeks). Fluoride concentrations were measured in the crest, the middle, and the apical parts of the alveolar bone and in the body of the mandible. Furthermore, after fluoridated drinking water was given to rats for 4 or 13 weeks, distilled water was given to them for 21 or 12 weeks respectively; and the effect of the discontinuation on fluoride profiles was investigated. Layer samples were analyzed by abrasive microsampling. Fluoride and phosphorus concentrations were determined by ion-specific electrode and colorimetric procedures, respectively. There was an increase in fluoride concentrations in the mandible in proportion to the fluoride content in the drinking water and the duration of fluoridation. After fluoridation was discontinued, fluoride concentrations in the surface layers of the mandible presented a decrease. Among the four different parts of the mandible, the upper part of the alveolar bone and the alveolar crest part presented the highest rates of reduction. The relative reduction rate of fluoride concentration was closely related to the duration of discontinuation. The alveolar crest was affected most by the discontinuation of fluoridation, presenting the greatest reduction.

Self healing hemophilic pseudotumor of the mandible in a 5-year-old boy, an interesting and rare finding: Case report and review.

PubMed

Prasad, Ruchika Keshaw; Siva, B; Rajpal, Jaisika; Singh, Ankur

2016-01-01

Hemophilic pseudotumor (PT) is a very rare complication of hemophilia consisting of a chronic, encapsulated, hemorrhagic fluid collection occurring both in the soft tissues and/or bone. Radiological features of osseous hemophilic PT are nonspecific and mimic several other benign or malignant bone tumors or infectious processes. Although the diagnosis is usually made on the location of the lesion and by the knowledge of the underlying disease, the radiologist should be aware of the imaging characteristics, in order to avoid misinterpretation as a malignant tumor, as biopsy of these lesions is contraindicated.

A new species of Psammogammarus (Amphipoda: Melitidae) from Kuchinoerabu Island, Japan, with a note on its feeding habits.

PubMed

Tomikawa, Ko; Kakui, Keiichi; Yamasaki, Hiroshi

2010-07-01

A new melitoid Amphipoda, Psammogammarus mawatarii, is described from Kuchinoerabu Island, Kagoshima Prefecture, Japan. This is the first record of the genus from Asia. The new species is morphologically similar to P. garthi, but differs from the latter in the following features: 1) lateral cephalic lobe of head not strongly produced; 2) head lacking antennal sinus; and 3) posteroventral corner of epimeral plate 3 rounded. Morphology of maxillae 1 and 2, and mandible, and gut contents (harpacticoid Copepoda) of P. mawatarii indicate that the feeding type of the species seems to be, at least facultatively, carnivorous.

Management of mandibular body fractures in pediatric patients: a case report with review of literature.

PubMed

John, Baby; John, Reena R; Stalin, A; Elango, Indumathi

2010-10-01

Mandibular fractures are relatively less frequent in children when compared to adults, which may be due to the child's protected anatomic features and infrequent exposure of children to alcohol related traffic accidents. Treatment principles of mandibular fractures differ from that of adults due to concerns regarding mandibular growth and development of dentition. A case of a 4.5-year-old boy with fractured body of mandible managed by closed reduction using open occlusal acrylic splint and circum mandibular wiring is presented. This article also provides a review of literature regarding the management of mandibular body fracture in young children.

Management of mandibular body fractures in pediatric patients: A case report with review of literature

PubMed Central

John, Baby; John, Reena R.; Stalin, A.; Elango, Indumathi

2010-01-01

Mandibular fractures are relatively less frequent in children when compared to adults, which may be due to the child's protected anatomic features and infrequent exposure of children to alcohol related traffic accidents. Treatment principles of mandibular fractures differ from that of adults due to concerns regarding mandibular growth and development of dentition. A case of a 4.5-year-old boy with fractured body of mandible managed by closed reduction using open occlusal acrylic splint and circum mandibular wiring is presented. This article also provides a review of literature regarding the management of mandibular body fracture in young children. PMID:22114443

Management of pediatric mandibular fracture using orthodontic vacuum-formed thermoplastic splint: A case report and review of literature.

PubMed

Sanu, O O; Ayodele, Aos; Akeredolu, M O

2017-05-01

Fractures of the mandible are relatively less frequent in children when compared to adults. The anatomic features of children are protected. Children have a higher adaptation to maxillofacial fractures compared to adults. Treatment principles of mandibular fractures in children differ from that of adults due to concerns regarding mandibular growth and the developing dentition. A case of a 6-year-old boy with fractured mandibular symphysis managed by closed reduction using a vacuum formed thermoplastic splint and circummandibular wiring is presented. This article also provides a review of the literature regarding the management of mandibular fracture in young children.

[Anatomical rationale for lingual nerve injury prevention during mandibular block].

PubMed

Semkin, V A; Dydikin, S S; Kuzin, A V; Sogacheva, V V

2015-01-01

The topographic and anatomical study of lingual nerve structural features was done. It was revealed that during mandibular anesthesia possible lingual nerve injury can occur if puncture needle is lower than 1 cm. of molars occlusal surface level. The position of the lingual nerve varies withmandible movements. At the maximum open mouth lingual nerve is not mobile and is pressed against the inner surface of the mandibular ramus by the medial pterygoid muscle and the temporal muscle tendon. When closing the mouth to 1.25±0.2 cmfrom the physiological maximum, lingual nerve is displaced posteriorly from the internal oblique line of the mandible and gets mobile. On the basis of topographic and anatomic features of the lingual nervestructure the authors recommend the re-do of inferior alveolar nerve block, a semi-closed mouth position or the use the "high block techniques" (Torus anesthesia, Gow-Gates, Vazirani-Akinozi).

Bilateral bifid mandibular canal

PubMed Central

Sheikhi, Mahnaz; Badrian, Hamid; Ghorbanizadeh, Sajad

2012-01-01

One of the normal interesting variations that we may encounter in the mandible is bifid mandibular canal. This condition can lead to difficulties when performing mandibular anesthesia or during extraction of lower third molar, placement of implants, and surgery in the mandible. Therefore diagnosis of this variation is sometimes very important and necessary. PMID:23814555

[An updated review of 1p36 deletion (monosomy) syndrome].

PubMed

Bello, Sabina; Rodríguez-Moreno, Antonio

The Monosomy 1p36 deletion syndrome is part of the group of diseases known as Rare Diseases. The objective of the present work is to review the characteristics of Monosomy 1p36 deletion syndrome. The monosomy 1p36 deletion syndrome phenotype includes: dysmorphic craniofacial features; large anterior fontanelle, unibrow, deep-set eyes, epicanthus, wide nasal root/bridge, mandible hypoplasia, abnormal location of the pinna, philtrum and pointed chin; neurological alterations: seizures and hydrocephalus (in some cases). Cerebral malformations: ventricular hypertrophy, increased subarachnoid space, morphological alterations of corpus callosum, cortical atrophy, delays in myelinisation, periventricular leukomalacia and periventricular heterotopia. These alterations produce intellectual disability and delays in motor growth, communication skills, language, social and adaptive behaviour. It is Hearing and vision impairments are also observed in subjects with this syndrome, as well as alterations of cardiac, endocrine and urinary systems and alterations at skin and skeletal level. Approximately 100 cases have been documented since 1981. This rare disease is the most common subtelomeric-micro-deletion syndrome. In situ hybridization with fluorescence (FISH) and array-comparative genomic hybridization (CGH-array) are at present the two best diagnostic techniques. There is currently no effective medical treatment for this disease. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Segmentation of organs-at-risks in head and neck CT images using convolutional neural networks

PubMed Central

Ibragimov, Bulat; Xing, Lei

2017-01-01

Purpose Accurate segmentation of organs-at-risks (OARs) is the key step for efficient planning of radiation therapy for head and neck (HaN) cancer treatment. In the work, we proposed the first deep learning-based algorithm, for segmentation of OARs in HaN CT images, and compared its performance against state-of-the-art automated segmentation algorithms, commercial software and inter-observer variability. Methods Convolutional neural networks (CNNs) – a concept from the field of deep learning – were used to study consistent intensity patterns of OARs from training CT images and to segment the OAR in a previously unseen test CT image. For CNN training, we extracted a representative number of positive intensity patches around voxels that belong to the OAR of interest in training CT images, and negative intensity patches around voxels that belong to the surrounding structures. These patches then passed through a sequence of CNN layers that captured local image features such as corners, end-points and edges, and combined them into more complex high-order features that can efficiently describe the OAR. The trained network was applied to classify voxels in a region of interest in the test image where the corresponding OAR is expected to be located. We then smoothed the obtained classification results by using Markov random fields algorithm. We finally extracted the largest connected component of the smoothed voxels classified as the OAR by CNN, performed dilate-erode operations to remov cavities of the component, which resulted in segmentation of the OAR in the test image. Results The performance of CNNs was validated on segmentation of spinal cord, mandible, parotid glands, submandibular glands, larynx, pharynx, eye globes, optic nerves and optic chiasm using 50 CT images. The obtained segmentation results varied from 37.4% Dice coefficient (DSC) for chiasm to 89.5% DSC for mandible. We also analyzed the performance of state-of-the-art algorithms and commercial software reported in the literature, and observed that CNNs demonstrate similar or superior performance on segmentation of spinal cord, mandible, parotid glands, larynx, pharynx, eye globes and optic nerves, but inferior performance on segmentation of submandibular glands and optic chiasm. Conclusion We concluded that convolution neural networks can accurately segment most of OARs using a representative database of 50 HaN CT images. At the same time, inclusion of additional information, e.g. MR images, may be beneficial for some OARs with poorly-visible boundaries. PMID:28205307

Impact of Injury Mechanisms on Patterns and Management of Facial Fractures.

PubMed

Greathouse, S Travis; Adkinson, Joshua M; Garza, Ramon; Gilstrap, Jarom; Miller, Nathan F; Eid, Sherrine M; Murphy, Robert X

2015-07-01

Mechanisms causing facial fractures have evolved over time and may be predictive of the types of injuries sustained. The objective of this study is to examine the impact of mechanisms of injury on the type and management of facial fractures at our Level 1 Trauma Center. The authors performed an Institutional Review Board-approved review of our network's trauma registry from 2006 to 2010, documenting age, sex, mechanism, Injury Severity Score, Glasgow Coma Scale, facial fracture patterns (nasal, maxillary/malar, orbital, mandible), and reconstructions. Mechanism rates were compared using a Pearson χ2 test. The database identified 23,318 patients, including 1686 patients with facial fractures and a subset of 1505 patients sustaining 2094 fractures by motor vehicle collision (MVC), fall, or assault. Nasal fractures were the most common injuries sustained by all mechanisms. MVCs were most likely to cause nasal and malar/maxillary fractures (P < 0.01). Falls were the least likely and assaults the most likely to cause mandible fractures (P < 0.001), the most common injury leading to surgical intervention (P < 0.001). Although not statistically significant, fractures sustained in MVCs were the most likely overall to undergo surgical intervention. Age, number of fractures, and alcohol level were statistically significant variables associated with operative management. Age and number of fractures sustained were associated with operative intervention. Although there is a statistically significant correlation between mechanism of injury and type of facial fracture sustained, none of the mechanisms evaluated herein are statistically associated with surgical intervention. Clinical Question/Level of Evidence: Therapeutic, III.

Common avian infection plagued the tyrant dinosaurs.

PubMed

Wolff, Ewan D S; Salisbury, Steven W; Horner, John R; Varricchio, David J

2009-09-30

Tyrannosaurus rex and other tyrannosaurid fossils often display multiple, smooth-edged full-thickness erosive lesions on the mandible, either unilaterally or bilaterally. The cause of these lesions in the Tyrannosaurus rex specimen FMNH PR2081 (known informally by the name 'Sue') has previously been attributed to actinomycosis, a bacterial bone infection, or bite wounds from other tyrannosaurids. We conducted an extensive survey of tyrannosaurid specimens and identified ten individuals with full-thickness erosive lesions. These lesions were described, measured and photographed for comparison with one another. We also conducted an extensive survey of related archosaurs for similar lesions. We show here that these lesions are consistent with those caused by an avian parasitic infection called trichomonosis, which causes similar abnormalities on the mandible of modern birds, in particular raptors. This finding represents the first evidence for the ancient evolutionary origin of an avian transmissible disease in non-avian theropod dinosaurs. It also provides a valuable insight into the palaeobiology of these now extinct animals. Based on the frequency with which these lesions occur, we hypothesize that tyrannosaurids were commonly infected by a Trichomonas gallinae-like protozoan. For tyrannosaurid populations, the only non-avian dinosaur group that show trichomonosis-type lesions, it is likely that the disease became endemic and spread as a result of antagonistic intraspecific behavior, consumption of prey infected by a Trichomonas gallinae-like protozoan and possibly even cannibalism. The severity of trichomonosis-related lesions in specimens such as Tyrannosaurus rex FMNH PR2081 and Tyrannosaurus rex MOR 980, strongly suggests that these animals died as a direct result of this disease, mostly likely through starvation.

Congenital zygomatico-mandibular fusion (pseudo-syngnathia?) in conjunction with unilateral anophthalmia: review of terminology and classification.

PubMed

Tauro, David P; Kallappanavar, N K; Kiran, H Y; Girhe, Vijaykumar J

2012-09-01

Syngnathia per se is a rare congenital disorder. A literature survey reveals a total of 26 cases of syngnathia in the English literature since 1936, of which only seven cases involved fusion of the ascending ramus of the mandible to the posterior portion of the maxilla and zygomatic complex. The remaining 19 involved fusion of the alveolar ridges of the maxilla and mandible. This is a unique case of fusion of the mandible to the zygomatic complex presenting with a unilateral anophthalmic orbit in an 18-day-old neonate. The use of the term syngnathia has been reviewed and a modification in classification has been suggested.

Temporal distribution of endogenous retinoids in the embryonic mouse mandible.

PubMed

Beeman, C S; Kronmiller, J E

1994-09-01

Retinoids play an important part in embryonic pattern formation. They are necessary for normal differentiation of odontogenic tissues and, in excess, disrupt the pattern of tooth formation. Excess retinoids produce supernumerary buds of the dental lamina in the diastema region of the mouse embryonic mandible where teeth do not normally form. This effect is coincident with an increase in epithelial proliferation and an alteration in epidermal growth factor mRNA expression (a gene product necessary for tooth formation). It was found by high-performance liquid chromatography that endogenous retinoids are present in the developing murine mandible and that concentrations of some retinoids reach a peak at the time of the initiation of odontogenesis (dental lamina formation).

Spatial distribution of endogenous retinoids in the murine embryonic mandible.

PubMed

Kronmiller, J E; Beeman, C S

1994-12-01

Retinoids play an important part in pattern formation during embryonic development. Exogenous retinoids alter the pattern of skeletal, neural and odontogenic tissues. Endogenous retinoids have been demonstrated previously in the murine embryonic mandible, reaching a concentration peak during the initiation of odontogenesis. It was now found that endogenous retinoids are present in a concentration gradient in the embryonic mouse mandible at the time of the initiation of the dental lamina. All-trans-retinoic acid was more concentrated in the incisor region and retinol in the molar region. These results, and the fact that exogenous retinoids produce supernumerary incisors and missing molars, suggest that all-trans-retinoic acid may instruct incisor morphology.

Cineradiographic Examination of Articulatory Movement of Pseudo-Tongue, Hyoid, and Mandible in Congenital Aglossia

ERIC Educational Resources Information Center

McMicken, Betty; Vento-Wilson, Margaret; Von Berg, Shelley; Rogers, Kelly

2014-01-01

This research examined cineradiographic films (CRF) of articulatory movements in a person with congenital aglossia (PWCA) during speech production of four phrases. Pearson correlations and a multiple regression model investigated co-variation of independent variables, positions of mandible and hyoid; and pseudo-tongue-dependent variables,…

Duplication of lower lip and mandible--a rare diprosopus.

PubMed

Suhaili, D N Pengiran; Somasundaram, S; Lau, S H; Ajura, A J; Roslan, A R; Ramli, R

2011-01-01

Diprosopus or duplication of the lower lip and mandible is a very rare congenital anomaly. We report this unusual case occurring in a girl who presented to our hospital at the age of 4 months. Surgery and problems related to this anomaly are discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Finite element analysis of the human mastication cycle.

PubMed

Commisso, Maria S; Martínez-Reina, Javier; Ojeda, Joaquín; Mayo, Juana

2015-01-01

The aim of this paper is to propose a biomechanical model that could serve as a tool to overcome some difficulties encountered in experimental studies of the mandible. One of these difficulties is the inaccessibility of the temporomandibular joint (TMJ) and the lateral pterygoid muscle. The focus of this model is to study the stresses in the joint and the influence of the lateral pterygoid muscle on the mandible movement. A finite element model of the mandible, including the TMJ, was built to simulate the process of unilateral mastication. Different activation patterns of the left and right pterygoid muscles were tried. The maximum stresses in the articular disc and in the whole mandible during a complete mastication cycle were reached during the instant of centric occlusion. The simulations show a great influence of the coordination of the right and left lateral pterygoid muscles on the movement of the jaw during mastication. An asynchronous activation of the lateral pterygoid muscles is needed to achieve a normal movement of the jaw during mastication. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pre-operative planning for mandibular reconstruction - A full digital planning workflow resulting in a patient specific reconstruction

PubMed Central

2011-01-01

Objectives Reconstruction of large mandiblular defects following ablative oncologic surgery could be done by using vascularized bone transfer or, more often, primarily with simultaneous or delayed bone grafting, using load bearing reconstruction plates. Bending of these reconstruction plates is typically directed along the outer contour of the original mandible. Simultaneously or in a second operation vascularized or non-vascularized bone is fixed to the reconstruction plate. However, the prosthodontic-driven backward planning to ease bony reconstruction of the mandible in terms of dental rehabilitation using implant-retained overdentures might be an eligible solution. The purpose of this work was to develop, establish and clinically evaluate a novel 3D planning procedure for mandibular reconstruction. Materials and methods Three patients with tumors involving the mandible, which included squamous cell carcinoma in the floor of the mouth and keratocystic odontogenic tumor, were treated surgically by hemimandibulectomy. Results In primary alloplastic mandible reconstruction, shape and size of the reconstruction plate could be predefined and prebent prior to surgery. Clinical relevance This study provides modern treatment strategies for mandibular reconstruction. PMID:21968330

Application of two segmentation protocols during the processing of virtual images in rapid prototyping: ex vivo study with human dry mandibles.

PubMed

Ferraz, Eduardo Gomes; Andrade, Lucio Costa Safira; dos Santos, Aline Rode; Torregrossa, Vinicius Rabelo; Rubira-Bullen, Izabel Regina Fischer; Sarmento, Viviane Almeida

2013-12-01

The aim of this study was to evaluate the accuracy of virtual three-dimensional (3D) reconstructions of human dry mandibles, produced from two segmentation protocols ("outline only" and "all-boundary lines"). Twenty virtual three-dimensional (3D) images were built from computed tomography exam (CT) of 10 dry mandibles, in which linear measurements between anatomical landmarks were obtained and compared to an error probability of 5 %. The results showed no statistically significant difference among the dry mandibles and the virtual 3D reconstructions produced from segmentation protocols tested (p = 0,24). During the designing of a virtual 3D reconstruction, both "outline only" and "all-boundary lines" segmentation protocols can be used. Virtual processing of CT images is the most complex stage during the manufacture of the biomodel. Establishing a better protocol during this phase allows the construction of a biomodel with characteristics that are closer to the original anatomical structures. This is essential to ensure a correct preoperative planning and a suitable treatment.

Exploration of the Genetic Organization of Morphological Modularity on the Mouse Mandible Using a Set of Interspecific Recombinant Congenic Strains Between C57BL/6 and Mice of the Mus spretus Species

PubMed Central

Burgio, Gaëtan; Baylac, Michel; Heyer, Evelyne; Montagutelli, Xavier

2012-01-01

Morphological integration and modularity within semi-autonomous modules are essential mechanisms for the evolution of morphological traits. However, the genetic makeup responsible for the control of variational modularity is still relatively unknown. In our study, we tested the hypothesis that the genetic variation for mandible shape clustered into two morphogenetic components: the alveolar group and the ascending ramus. We used the mouse as a model system to investigate genetics determinants of mandible shape. To do this, we used a combination of geometric morphometric tools and a set of 18 interspecific recombinant congenic strains (IRCS) derived from the distantly related species, Mus spretus SEG/Pas and Mus musculus C57BL/6. Quantitative trait loci (QTL) analysis comparing mandible morphometry between the C57BL/6 and the IRCSs identified 42 putative SEG/Pas segments responsible for the genetic variation. The magnitude of the QTL effects was dependent on the proportion of SEG/Pas genome inherited. Using a multivariate correlation coefficient adapted for modularity assessment and a two-block partial least squares analysis to explore the morphological integration, we found that these QTL clustered into two well-integrated morphogenetic groups, corresponding to the ascending ramus and the alveolar region. Together, these results provide evidence that the mouse mandible is subjected to genetic coordination in a modular manner. PMID:23050236

Postglacial recolonization and Holocene diversification of Crocidura suaveolens (Mammalia, Soricidae) on the north-western fringe of the European continent

NASA Astrophysics Data System (ADS)

Rofes, Juan; Cucchi, Thomas; Hanot, Pauline; Herman, Jeremy; Stephan, Pierre; Cersoy, Sophie; Horáček, Ivan; Kerr, Elizabeth; Allberry, Kate; Valenzuela, Silvia; Zazzo, Antoine; Cornette, Raphaël; Tresset, Anne

2018-06-01

Phenotypic variation was characterized in 187 modern and archaeological specimens of the lesser white-toothed shrew (Crocidura suaveolens), obtained from both insular and continental European locations. Geometric morphometric methods were used to quantify variation in size and shape of the mandible. The phenotypic distance between populations, and the influence of several eco-geographical factors on the size and shape of the mandible in island populations, were assessed. Based on mandible shape divergence, the populations of C. suaveolens were clustered into continental, insular Atlantic and insular Mediterranean groups. Archaeological specimens from Molène Island, more than 3400 years old, display a mandible shape signal closer to that of the continental population than those of modern island populations. Conversely, the continental shape signals of the modern populations from Höedic and Sark suggest that these are relatively recent anthropogenic introductions. The populations of C. suaveolens from both the Atlantic and Mediterranean islands (except for Rouzic and Cyprus) show a significant increase in mandible size, compared to those from continental Europe. Significant phenotypic differences support the indigenous condition of C. suaveolens on most of the Atlantic islands, suggesting that the species arrived there before the separation of the Scilly Isles and Ushant from the continent due to the post-glacial rise in sea level. This provides an ante quem for its colonization of the north-western fringe of continental Europe, notwithstanding its absence from the region in the present day.

Biomechanical analysis comparing natural and alloplastic temporomandibular joint replacement using a finite element model.

PubMed

Mesnard, Michel; Ramos, Antonio; Ballu, Alex; Morlier, Julien; Cid, M; Simoes, J A

2011-04-01

Prosthetic materials and bone present quite different mechanical properties. Consequently, mandible reconstruction with metallic materials (or a mandible condyle implant) modifies the physiologic behavior of the mandible (stress, strain patterns, and condyle displacements). The changing of bone strain distribution results in an adaptation of the temporomandibular joint, including articular contacts. Using a validated finite element model, the natural mandible strains and condyle displacements were evaluated. Modifications of strains and displacements were then assessed for 2 different temporomandibular joint implants. Because materials and geometry play important key roles, mechanical properties of cortical bone were taken into account in models used in finite element analysis. The finite element model allowed verification of the worst loading configuration of the mandibular condyle. Replacing the natural condyle by 1 of the 2 tested implants, the results also show the importance of the implant geometry concerning biomechanical mandibular behavior. The implant geometry and stiffness influenced mainly strain distribution. The different forces applied to the mandible by the elevator muscles, teeth, and joint loads indicate that the finite element model is a relevant tool to optimize implant geometry or, in a subsequent study, to choose a more suitable distribution of the screws. Bone screws (number and position) have a significant influence on mandibular behavior and on implant stress pattern. Stress concentration and implant fracture must be avoided. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Evolution of Skull and Mandible Shape in Cats (Carnivora: Felidae)

PubMed Central

Christiansen, Per

2008-01-01

The felid family consists of two major subgroups, the sabretoothed and the feline cats, to which all extant species belong, and are the most anatomically derived of all carnivores for predation on large prey with a precision killing bite. There has been much controversy and uncertainty about why the skulls and mandibles of sabretoothed and feline cats evolved to become so anatomically divergent, but previous models have focused on single characters and no unifying hypothesis of evolutionary shape changes has been formulated. Here I show that the shape of the skull and mandible in derived sabrecats occupy entirely different positions within overall morphospace from feline cats, and that the evolution of skull and mandible shape has followed very different paths in the two subgroups. When normalised for body-size differences, evolution of bite forces differ markedly in the two groups, and are much lower in derived sabrecats, and they show a significant relationship with size and cranial shape, whereas no such relationship is present in feline cats. Evolution of skull and mandible shape in modern cats has been governed by the need for uniform powerful biting irrespective of body size, whereas in sabrecats, shape evolution was governed by selective pressures for efficient predation with hypertrophied upper canines at high gape angles, and bite forces were secondary and became progressively weaker during sabrecat evolution. The current study emphasises combinations of new techniques for morphological shape analysis and biomechanical studies to formulate evolutionary hypotheses for difficult groups. PMID:18665225

The Design of Mechanically Compatible Fasteners for Human Mandible Reconstruction

NASA Technical Reports Server (NTRS)

Roberts, Jack C.; Ecker, John A.; Biermann, Paul J.

1993-01-01

Mechanically compatible fasteners for use with thin or weakened bone sections in the human mandible are being developed to help reduce large strain discontinuities across the bone/implant interface. Materials being considered for these fasteners are a polyetherertherketone (PEEK) resin with continuous quartz or carbon fiber for the screw. The screws were designed to have a shear strength equivalent to that of compact/trabecular bone and to be used with a conventional nut, nut plate, or an expandable shank/blind nut made of a ceramic filled polymer. Physical and finite element models of the mandible were developed in order to help select the best material fastener design. The models replicate the softer inner core of trabecular bone and the hard outer shell of compact bone. The inner core of the physical model consisted of an expanding foam and the hard outer shell consisted of ceramic particles in an epoxy matrix. This model has some of the cutting and drilling attributes of bone and may be appropriate as an educational tool for surgeons and medical students. The finite element model was exercised to establish boundary conditions consistent with the stress profiles associated with mandible bite forces and muscle loads. Work is continuing to compare stress/strain profiles of a reconstructed mandible with the results from the finite element model. When optimized, these design and fastening techniques may be applicable, not only to other skeletal structures, but to any composite structure.

Cephalometric superimpositions.

PubMed

Gu, Yan; McNamara, James A

2008-11-01

To test the hypothesis that there is no difference between the information produced by superimposition of serial lateral headfilms on anatomical structures and that produced by superimposition on metallic implants according to the protocols of Björk. Serial cephalograms of 10 untreated subjects who had tantalum implants placed in the maxilla and mandible during childhood were analyzed. Headfilms taken at six consecutive stages of cervical vertebral maturation (CS1-CS6) for six female and four male subjects were used. Tracings were superimposed according to the methods of superimpositions advocated by the American Board of Orthodontics (ABO). In addition, superimpositions along the inferior border of the mandible were performed. Finally, superimpositions of serial tracings on stable intraosseous implants were made to determine the actual growth and remodeling patterns of the maxilla and mandible. The ABO maxillary superimposition method underestimates the vertical displacement and overestimates the forward movement of maxillary landmarks. Superimposing on the internal cortical outline of the symphysis and the inferior alveolar nerve canals generally approximates the mandibular superimposition on implants, although the lower anterior border of the symphysis may be a preferable area of superimposition. Superimposition on the lower border of the mandible does not reflect accurately the actual pattern of growth and remodeling of the mandible. When analyzing serial headfilms, erroneous information concerning patterns of bone growth and remodeling can be obtained if convenient, but biologically incorrect superimposition protocols are used. In addition, tooth movements measured can be distorted significantly depending on the method of superimposition.

An ultrastructural study on indirect injury of dental pulp caused by high-speed missile projectile to mandible in dogs.

PubMed

Ren, Changqun; Liu, Ruifeng; Tian, Lei; Chen, Peng; Zhou, Shuxia

2008-12-01

The aim of this study was to evaluate the characteristics of indirect injury of dental pulp caused by high-speed missile projectile to mandible in dogs. Eighteen dogs aged 12-13 months were divided equally into six groups (n = 3 in each group) with random allocation, then a high-speed missile projectile (a ball bearing of stainless steel, phi6.0 mm, 0.88 g) was shot at right mandible body (the wound tract was below the fourth premolar, 1 cm or so to the root tips) of each dog, but the teeth were not wounded directly. The dogs were killed 6 h (n = 3), 24 h (n = 3), 3 days (n = 3), 7 days (n = 3), 2 weeks (n = 3) and 4 weeks (n = 3) after the wound, respectively; then ultrastructural change of dental pulp of the fourth premolar and the second premolar of right mandible, and the second premolar of left mandible was observed through transmission electron microscope. The results showed that mean initial velocity of projectiles was 778.0 +/- 33.2 m s(-1) and mean projection energy was 266.1 +/- 19.1 J, which were in conformity with parameters of gunshot wound. On the wound side, dental pulp of the fourth mandibular premolar was injured seriously and irreversible necrosis happened in the end; yet, dental pulp of the second mandibular premolar was injured less seriously, reversibly; on the opposite side, dental pulp of the second mandibular premolar was injured slightly and temporarily. It may be concluded that there are several characteristics in indirect injury of dental pulp caused by high-speed missile projectile to dogs' mandible: the injured area is relatively extensive; traumatic degree decreases progressively and sharply with the distance to the wound tract increasing; ultrastructural change of nerval damage takes place in early stage after wound, etc.

Simple bone cyst of mandible mimicking periapical cyst.

PubMed

Hs, Charan Babu; Rai, Bhagawan Das; Nair, Manju A; Astekar, Madhusudan S

2012-05-29

Simple bone cysts (SBC) are pseudocysts occurring less commonly in the maxillofacial region. The uncertain and unclear etiopathogenesis led to numerous synonyms to refer this particular cyst. These cysts are devoid of an epithelial lining and are usually empty or contain blood or straw-colored fluid. In jaws initially it mimics a periapical cyst and later can lead to cortical bone expansion warranting for radical approach, which is seldom required. SBC is predominantly diagnosed in first two decades of life. Here we report a case of solitary bone cyst mimicking a periapical cyst of a mandibular molar in a 37-year-old patient.

Imaging of Dentoalveolar and Jaw Trauma.

PubMed

Alimohammadi, Reyhaneh

2018-01-01

Prior to the invention of cone beam CT, use of 2-D plain film imaging for trauma involving the mandible was common practice, with CT imaging opted for in cases of more complex situations, especially in the maxilla and related structures. Cone beam CT has emerged as a reasonable and reliable alternative considering radiation dosage, image quality, and comfort for the patient. This article presents an overview of the patterns of dental and maxillofacial fractures using conventional and advanced imaging techniques illustrated with multiple clinical examples selected from the author's oral and maxillofacial radiology practice database. Published by Elsevier Inc.

Recurrent keratocystic odontogenic tumor of right maxillary sinus involving the right infraorbital rim.

PubMed

Maruthamuthu, Karthikeyan; Vasupradha, G; Dineshshankar, Janardhanam; Balaji, Abishek Rajaram

2017-01-01

Keratocystic odontogenic tumor (KCOT) is a benign odontogenic tumor with an aggressive behavior and high recurrence rate. The most common site of predilection is the posterior mandible. In contrast, KCOTs occurring in the maxillary region are relatively rare. However, the maxillary involvement poses a greater and increased threat, due to proximity to vital structures such as maxillary sinus, orbital floor, and infratemporal fossa. This report presents such a case of KCOT involving the maxillary sinus eroding the floor of the orbit and provides an account of the factors that need to be considered during management.

Mouthparts and nectar feeding of the flower visiting cricket Glomeremus orchidophilus (Gryllacrididae).

PubMed

Krenn, Harald W; Fournel, Jacques; Bauder, Julia A-S; Hugel, Sylvain

2016-05-01

Glomeremus orchidophilus (Gryllacrididae) is a flower visiting cricket on the tropical island La Réunion. This species is the only Orthoptera shown to be a pollinator of a plant. We studied its nectar feeding behavior and mouthpart morphology in detail. Since G. orchidophilus possesses biting-and-chewing mouthparts, our objective was to find behavioral and/or structural specializations for nectar-feeding. The comparative analysis of feeding behavior revealed that fluid is taken up without movements of the mouthparts in Glomeremus. A comparative morphological examination of two Glomeremus species, together with several representatives of other Gryllacrididae and other Ensifera taxa revealed subtle adaptations to fluid feeding in Glomeremus. All representatives of Gryllacrididae were found to possess a distinct patch of microtrichia at the tip of their galeae. However, in Glomeremus a channel is formed between the distal components of the maxillae and the mandibles on each side of the body. Micro-CT and SEM examination revealed a longitudinal groove that extends over the galea beginning at the patch of microtrichia in the studied Glomeremus species. We hypothesize that the microtrichia take up fluid by capillarity and the action of the cibarium and pharyngeal pumps transports fluid along the channels between the maxillae and mandibles into the preoral cavity. These mouthpart features allow nectar uptake from flowers that is unique in Orthoptera. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multidisciplinary surgical management of cherubism complicated by neurofibromatosis type 1.

PubMed

Hachach-Haram, Nadine; Gerarchi, Paul; Benyon, Sarah L; Saggar, Anand; McLellan, Guy; Kirkpatrick, W Niall A

2011-11-01

Cherubism is a rare, autosomal dominant, mostly self-limiting disease of the jaw. It is characterized by bilateral fibrous tissue hyperplasia, giant cell proliferation, and bony degeneration in the lower facial skeleton, which can result in a massive and severely deforming prominence of the maxillomandibular structure. This case study examines the multidisciplinary management of a severe case of cherubism complicated by neurofibromatosis type 1, 2 codominant nonsegregating conditions that were clinically and genetically diagnosed, an extremely rare combination. Adequate mandibular reduction, reconstruction, and dental implantation afforded good restoration of oral function as well as a marked aesthetic improvement. A 14-year-old Fijian girl was referred to our unit for management of severe overgrowth of her mandible that compromised her speech and deglutition. In addition, she displayed clinical features consistent with neurofibromatosis type 1. Radiologic, histologic, and genetic analyses confirmed the diagnosis of both conditions. Our craniofacial multidisciplinary team undertook mandibular reconstruction followed by placement of osseointegrated dental implants. Mandibular reduction, reconstruction, and dental implantation resulted in a significantly improved functional and aesthetic outcome with no further regrowth at 3-year follow-up when she returned to the United Kingdom for osseointegrated dental implant insertion. The successful outcome of this surgically challenging, grossly disfiguring, and rare condition was largely a result of the combined input from our multidisciplinary team, adequate preoperative planning, and the use of a novel surgical technique in debulking and reconstructing her mandible.

78 FR 61621 - Endangered and Threatened Wildlife and Plants; Proposed Threatened Status for the Western...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... length, depth of upper mandible, and wing length) of almost 700 specimens of adult yellow-billed cuckoos... wing length, bill length, and mandible depth; and (3) no statistically significant differences for... west side of the Cascades at the Sandy River Delta near its confluence with the Columbia River in July...

The mandibular canal of the "old man" of Cro-Magnon: anatomical-radiological study.

PubMed

Goudot, Patrick

2002-08-01

The radiological study of the 'old man' of Cro-Magnon mandible complements the one published about the mandibular canal of the "Neanderthal Man" of La Chapelle-aux-Saints with which it is compared. The purpose of this study was to explore the internal structure of this famous fossil. The mandible of the "old man" of Cro-Magnon (22,000 BC) was studied with panoramic radiography and CT scanning. The mandibular canal is similar to that of modern man. The images obtained are of a good quality and can be used for analysis of the internal structures of bony fossils. The mandible of the "old man" of Cro-Magnon belongs to the species Homo sapiens sapiens. Copyright 2002 Published by Elsevier Science Ltd.

Measurement of intraosseous pressures generated by the Wand, high-pressure periodontal ligament syringe, and the Stabident system.

PubMed

Shepherd, P A; Eleazer, P D; Clark, S J; Scheetz, J P

2001-06-01

Intraosseous pressure generated by the use of three anesthetic systems-the Wand; a hand-operated high-pressure periodontal ligament (PDL) syringe; and the Stabident system-were studied in fresh mandibles of 14 large swine. The mandibles were drilled and tapped in one area of both the right and left posterior molar regions. Pressure gauges were attached via threaded fittings. Pressures during injection were recorded for the Wand first, then the PDL syringe, and finally Stabident. Results showed averages of 8.3 mm Hg generated by the Wand, 16.3 mm Hg with the high-pressure PDL syringe, and 43.7 mm Hg from the Stabident system. Results were corroborated with data from three human cadaver mandibles.

[Dynamic magnetotherapy use in comprehensive treatment phlegmons of maxillofacial region and mandible fractures].

PubMed

Lepilin, A V; Raĭgorodckiĭ, Iu M; Nozdrachev, V G; Erokina, N L

2007-01-01

145 patients (60 with phlegmons of submandibular and submental regions, 85--with fractures of mandible) were observed and treated with the use of moving pulse magnetic field (MPMF) produced by special apparatus (AMO-ATOS-E, , Saratov-city), 60 patients with the same pathology were treated by traditional physical methods and served as control. Use of MPMF led to quicker patient recovery: quicker reduction (if compared with traditional physical methods of treatment) of oedema and soft tissue inflammatory infiltration, quicker relief from inflammatory reaction (according to data of cytokinin profile), improvement of tissue blood supply in the region of fractures in patients with mandible fractures. As the result--we had shortening treatment terms of such patients and complication number reduction.

Unusual presentation of localized gingival enlargement associated with a slow-growing odontogenic myxoma

PubMed Central

Miranda Rius, Jaume; Nadal, Alfons; Lahor, Eduard; Mtui, Beatus; Brunet, Lluís

2013-01-01

Unusual presentation of localized gingival enlargement associated with a subjacent tumoural pathology is reported. The patient was a 55-year-old black male, whose chief complaint was a progressive gingival overgrowth for more than ten years, in the buccal area of the anterior left mandible. According to the clinical features and the radiological diagnosis of odontogenic keratocyst, a conservative surgery with enucleation and curettage was performed. Tissue submitted for histopathological analysis rendered the diagnosis of odontogenic myxoma. After 12-month of follow-up, no evidence of recurrence was found. Clinicians should be cautious when facing any gingival enlargement to avoid diagnostic pitfalls and to indicate the appropriate treatment. PMID:23722914

Orthokeratinised odontogenic cyst mimicking periapical cyst

PubMed Central

Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

2013-01-01

Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth. PMID:24099763

Orthokeratinised odontogenic cyst mimicking periapical cyst.

PubMed

Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

2013-10-07

Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth.

Dietary correlates of temporomandibular joint morphology in the great apes.

PubMed

Terhune, Claire E

2013-02-01

Behavioral observations of great apes have consistently identified differences in feeding behavior among species, and these differences have been linked to variation in masticatory form. As the point at which the mandible and cranium articulate, the temporomandibular joint (TMJ) is an important component of the masticatory apparatus. Forces are transmitted between the mandible and cranium via the TMJ, and this joint helps govern mandibular range of motion. This study examined the extent to which TMJ form covaries with feeding behavior in the great apes by testing a series of biomechanical hypotheses relating to specific components of joint shape using linear measurements extracted from three-dimensional coordinate data. Results of these analyses found that taxa differ significantly in TMJ shape, particularly in the mandibular fossa. Chimpanzees have relatively more anteroposteriorly elongated joint surfaces, whereas gorillas tend to have relatively anteroposteriorly compressed joints. Orangutans were most commonly intermediate in form between Pan and Gorilla, perhaps reflecting a trade-off between jaw gape and load resistance capabilities. Importantly, much of the observed variation among taxa reflects differences in morphologies that facilitate gape over force production. These data therefore continue to emphasize the unclear relationship between mandibular loading and bony morphology, but highlight the need for further data regarding food material properties, jaw gape, and ingestive/food processing behaviors. Copyright © 2012 Wiley Periodicals, Inc.

Partial craniofacial duplication: a review of the literature and case report.

PubMed

Costa, Melinda A; Borzabadi-Farahani, Ali; Lara-Sanchez, Pedro A; Schweitzer, Daniela; Jacobson, Lia; Clarke, Noreen; Hammoudeh, Jeffery; Urata, Mark M; Magee, William P

2014-06-01

Diprosopus (Greek; di-, "two" + prosopon, "face"), or craniofacial duplication, is a rare craniofacial anomaly referring to the complete duplication of facial structures. Partial craniofacial duplication describes a broad spectrum of congenital anomalies, including duplications of the oral cavity. This paper describes a 15 month-old female with a duplicated oral cavity, mandible, and maxilla. A Tessier type 7 cleft, midline meningocele, and duplicated hypophysis were also present. The preoperative evaluation, surgical approach, postoperative results, and a review of the literature are presented. The surgical approach was designed to preserve facial nerve innervation to the reconstructed cheek and mouth. The duplicated mandible and maxilla were excised and the remaining left maxilla was bone grafted. Soft tissue repair included closure of the Tessier type VII cleft. Craniofacial duplication remains a rare entity that is more common in females. The pathophysiology remains incompletely characterized, but is postulated to be due to duplication of the notochord, as well as duplication of mandibular growth centres. While diprosopus is a severe deformity often associated with anencephaly, patients with partial duplication typically benefit from surgical treatment. Managing craniofacial duplication requires a detailed preoperative evaluation as well as a comprehensive, staged treatment plan. Long-term follow up is needed appropriately to address ongoing craniofacial deformity. Published by Elsevier Ltd.

Inpatients with gunshot wounds to the face.

PubMed

Sun, Gordon H; Patil, Yash J; Harmych, Brian M; Hom, David B

2012-01-01

Microvascular free tissue transfer (FTT) is an increasingly used method of reconstruction for traumatic defects of the head and neck. We describe the immediate management, FTT reconstruction techniques, and outcomes of 6 individuals who sustained maxillofacial gunshot trauma and were treated at a single tertiary-care level I trauma center. All 6 patients were white men with a mean age of 33 years. The mandible, nose, and orbital contents were the most frequently affected critical structures. All patients initially underwent primary wound debridement and tracheostomy, with concurrent maxillomandibular wire fixation and/or midface or mandible plate fixation in 5 patients. The mean time from injury to definitive FTT was 38 days. Five patients underwent fibula osteocutaneous FTT and 1 underwent radial forearm fasciocutaneous FTT. One patient also underwent concurrent local tissue rearrangement and pedicled flap surgery for nasal reconstruction. The mean hospital length of stay after FTT was 6 days. All FTT survived without necrosis. Oral incompetence and poor cosmesis from undesirable scarring patterns were the most common long-term complications. In summary, successful reconstruction of head and neck defects caused by gunshot trauma begins with airway stabilization, wound management, and bony fracture reduction and fixation. Definitive microvascular FTT is a useful method of repairing traumatic head and neck defects, although long-term functional and cosmetic complications may still occur.

Pattern and treatment of facial trauma in pediatric and adolescent patients.

PubMed

Muñante-Cárdenas, Jose Luis; Olate, Sergio; Asprino, Luciana; de Albergaria Barbosa, Jose Ricardo; de Moraes, Márcio; Moreira, Roger W F

2011-07-01

Pediatric maxillofacial trauma is a challenge for surgeons. There are no completely defined protocols, and sometimes, the initial management could be complex. The aim of this research was to perform a retrospective study to analyze the pattern and treatment of maxillofacial fractures in pediatric and adolescent patients. We reviewed the clinical records of 2986 patients treated at the Oral and Maxillofacial Surgery Division of Piracicaba Dental School between 1999 and 2008. Seven hundred fifty-seven patients were younger than 18 years and were divided into 3 groups according to age; the age and sex of the patients, etiology, fractures and associated injury, treatment, and complications were evaluated. Five hundred thirty boys (70.01%) and 227 girls (29.99%) were treated for injuries with major prevalence in adolescents. The most common injury causes were bicycle accidents (29.06%) and falls (28.40%). The mandible was the most fractured bone (44.8%); associated injuries were lacerations of the soft tissue and dental trauma. Surgical treatment was performed in 75 cases (30%) with minor complications (10% of surgical patients). We conclude that maxillofacial trauma in child is associated to fall and bicycle accidents; the mandible is more affected than other maxillofacial structures, and frequently, nonsurgical treatment is performed.

3D Rapid Prototyping for Otolaryngology-Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling.

PubMed

Chan, Harley H L; Siewerdsen, Jeffrey H; Vescan, Allan; Daly, Michael J; Prisman, Eitan; Irish, Jonathan C

2015-01-01

The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques across a variety of otolaryngological sub-specialties suggests an emerging role for rapid prototyping technology in surgical education, procedure simulation, and clinical practice.

3D Rapid Prototyping for Otolaryngology—Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling

PubMed Central

Chan, Harley H. L.; Siewerdsen, Jeffrey H.; Vescan, Allan; Daly, Michael J.; Prisman, Eitan; Irish, Jonathan C.

2015-01-01

The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques across a variety of otolaryngological sub-specialties suggests an emerging role for rapid prototyping technology in surgical education, procedure simulation, and clinical practice. PMID:26331717

Realization of masticatory movement by 3-dimensional simulation of the temporomandibular joint and the masticatory muscles.

PubMed

Park, Jong-Tae; Lee, Jae-Gi; Won, Sung-Yoon; Lee, Sang-Hee; Cha, Jung-Yul; Kim, Hee-Jin

2013-07-01

Masticatory muscles are closely involved in mastication, pronunciation, and swallowing, and it is therefore important to study the specific functions and dynamics of the mandibular and masticatory muscles. However, the shortness of muscle fibers and the diversity of movement directions make it difficult to study and simplify the dynamics of mastication. The purpose of this study was to use 3-dimensional (3D) simulation to observe the functions and movements of each of the masticatory muscles and the mandible while chewing. To simulate the masticatory movement, computed tomographic images were taken from a single Korean volunteer (30-year-old man), and skull image data were reconstructed in 3D (Mimics; Materialise, Leuven, Belgium). The 3D-reconstructed masticatory muscles were then attached to the 3D skull model. The masticatory movements were animated using Maya (Autodesk, San Rafael, CA) based on the mandibular motion path. During unilateral chewing, the mandible was found to move laterally toward the functional side by contracting the contralateral lateral pterygoid and ipsilateral temporalis muscles. During the initial mouth opening, only hinge movement was observed at the temporomandibular joint. During this period, the entire mandible rotated approximately 13 degrees toward the bicondylar horizontal plane. Continued movement of the mandible to full mouth opening occurred simultaneously with sliding and hinge movements, and the mandible rotated approximately 17 degrees toward the center of the mandibular ramus. The described approach can yield data for use in face animation and other simulation systems and for elucidating the functional components related to contraction and relaxation of muscles during mastication.

Architecture and Microstructure of Cortical Bone in Reconstructed Canine Mandibles after Bone Transport Distraction Osteogenesis

PubMed Central

Zapata, Uriel; Halvachs, Emily K.; Dechow, Paul C.; Elsalanty, Mohammed E.; Opperman, Lynne A.

2011-01-01

Purpose Reconstruction of the canine mandible using bone transport distraction osteogenesis has been shown to be a suitable method for correcting segmental bone defects produced by cancer, gunshots, and trauma. Although the mechanical quality of the new regenerate cortical bone seems to be related to the mineralization process, several questions regarding the micro-structural patterns of the new bony tissue remain unanswered. The purpose of this study was to quantify any microstructural differences that may exist between the regenerate and control cortical bone. Methods Five adult American foxhound dogs underwent unilateral bone transport distraction of the mandible to repair 30–35 mm bone defects. Animals were sacrificed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical cortical samples were extracted from the superior, medial, and inferior aspects of the lingual and buccal plates of the reconstructed aspect of the mandible and 21 specimens were collected similarly from the contralateral aspect of the mandible. The specimens were evaluated using histomorphometric and micro-computed tomography techniques to compare their microstructure. Results Except for differences in Haversian canal area, histomorphometric analyses suggested no statistical differences in microstructure between regenerate and control cortical bone. Morphological evaluation suggested a consistent level of anisotropy possibly related to the distraction vector. Conclusions After 12 weeks consolidation, bone created during bone transport distraction osteogenesis is comparable to native bone in microstructure, architecture, and mechanical properties. It is proposed that after enough time, the properties of the regenerate bone will be identical to that of native bone. PMID:21927873

Mechanical evaluation of the SLM fabricated, stiffness-matched, mandibular bone fixation plates

NASA Astrophysics Data System (ADS)

Jahadakbar, Ahmadreza; Shayesteh Moghaddam, Narges; Amerinatanzi, Amirhesam; Dean, David; Elahinia, Mohammad

2018-03-01

The standard of the care for the treatment of mandibular segmental defects is the use of Ti-6Al-4V bone fixation plates and screws to immobilize the grafted bone and the host mandible. While Ti-6Al-4V bone fixation plates provide strong immobilization during the healing period, they may disturb the stress distribution in the repaired mandible. The highly stiff Ti-6Al-4V fixation carries a great portion of the load which was previously borne by the mandible, and stress shielding may occur on the surrounding cortical bone. Based on the bone remodeling theory, stress shielding causes bone resorption in the effected region and may eventually lead to the failure of the surgical reconstruction. To address this issue, we have developed a new generation of the patient-specific, porous NiTi bone fixation plates which benefit from stiffness-matching of the adjacent bone. Using the CT scan data of the patient's defective mandible, the geometry for the required bone fixation plates is designed and the stiffness of the surrounding regions is measured. By introducing specific level and type of porosity to the bone fixation plate, its stiffness can be tuned. Finite Element simulations has verified the reduced level of stress shielding on the reconstructed mandible, in case of using the proposed bone fixation plates. Selective Lase Sintering has been used for fabrication of the porous NiTi bone fixation plates with six different levels of stiffness. Finite element simulations, and mechanical tests have been done to verify the performance of the fabricated parts resulting from our design and fabrication method.

A finite element study on the effects of midsymphyseal distraction osteogenesis on the mandible and articular disc.

PubMed

Kim, Ki-Nam; Cha, Bong-Kuen; Choi, Dong-Soon; Jang, Insan; Yi, Yang-Jin; Jost-Brinkmann, Paul-Georg

2012-05-01

To evaluate the biomechanical effect of midsymphyseal distraction osteogenesis with three types of distractors on the mandible and articular disc using a three-dimensional finite element model analysis. A virtual model of the mandible was produced from computed tomography scan images of a healthy 27-year-old man. On the finite element model of the mandible, expansion of the bone-borne, tooth-borne, and hybrid type distractors were simulated with the jaw-closing muscles. The displacement and stress distribution of the mandible and articular disc were analyzed. With the bone-borne appliance the alveolar process area was displaced more than the basal bone area. The tooth-borne appliance displaced the mandibular body in a parallel manner and showed high level of the von Mises stress in the alveolar process and the ramal region as well as in the condylar neck area. The hybrid type showed medium amount of displacement and stress distribution compared with the bone-borne and tooth-borne type. At the articular disc the compressive stress was concentrated in the anteromedial and posterolateral area, and it was highest in the tooth-borne distractor, followed by hybrid appliance and bone-borne appliance. The tooth-borne distractor produced more parallel bony widening in the midsymphyseal area and larger expansion in the molar region; however, it induced higher stress concentration on the articular disc than the hybrid appliance and bone-borne appliance. Whether any long-term side effects on the temporomandibular joint are anticipated, especially in tooth-borne distractor, remains to be investigated.

A resorbable and rapid method for maxillomandibular fixation in pediatric mandible fractures.

PubMed

Eppley, B L

2000-05-01

Maxillomandibular immobilization in pediatric mandible fractures is accomplished through a resorbable screw placed into the zygomatic body to which is attached a large, monofilament, circummandibular suture. Although the screw must be placed intraoperatively, this method of jaw immobilization is rapid, secure, does not damage the teeth, and can be removed in the office in the older child.

The use of resorbable hardware for fixation of pediatric mandible fracture. Case report.

PubMed

Poore, Matthew C; Penna, Kevin J

2008-01-01

The diagnosis and management of mandible fractures in the pediatric patient population can pose multiple challenges to the oral and maxillofacial surgeon. Resorbable plates and screws for fixation in this population are both well tolerated and effective. They enable realignment and stable positioning of rapidly healing fracture segments, while obviating any potential impediments to long-term metal retention.

Case report 834: Chronic sclerosing osteomyelitis of the mandible with long bone periostitis.

PubMed

Stewart, A; Carneiro, R; Pollock, L; Shaw, D

1994-04-01

We present the case of a patient with primary chronic osteomyelitis of the mandible, the radiological appearance of which is compatible with a diagnosis of chronic sclerosing osteomyelitis. The accompanying femoral and tibial periosteal reactive new bone formation and the benign clinical course suggest that this presentation may represent a form of chronic multifocal osteomyelitis.

Effect of pacifier use on mandibular position in preterm infants.

PubMed

Tonkin, Shirley L; Lui, Dana; McIntosh, Christine G; Rowley, Simon; Knight, David B; Gunn, Alistair J

2007-10-01

It has been hypothesized that the association of pacifier use with reduced risk of sudden infant death is mediated by forward movement of the mandible and tongue that helps open the upper airway. Our aim was to examine whether the mandible is moved forward when an infant is sucking on a pacifier, and if so, whether the mandible remains advanced after the pacifier is removed. In sixty clinically stable premature infants (corrected gestation age 36.5 +/- 0.3 weeks, mean +/- SEM) the distance from each ear where the pinna met the cheek to the most prominent point of the chin was measured bilaterally, and the average was used as an index of mandibular position. Mandibular position was determined before and after allowing the infants to suck on a pacifier for 10-15 min, and after removing the pacifier. There was a significant forward movement of the mandible when the infants were sucking on the pacifier (59.5 +/- 0.7 vs. 58.6 +/- 0.7 mm, p = 0.001), with no significant change after the pacifier was removed. Pacifier use in preterm infants was associated with a small significant forward displacement of the jaw. These data suggest that pacifier use may help protect the upper airway.

The Comprehensive AOCMF Classification System: Mandible Fractures- Level 2 Tutorial

PubMed Central

Cornelius, Carl-Peter; Audigé, Laurent; Kunz, Christoph; Rudderman, Randal; Buitrago-Téllez, Carlos H.; Frodel, John; Prein, Joachim

2014-01-01

This tutorial outlines the details of the AOCMF image-based classification system for fractures of the mandible at the precision level 2 allowing description of their topographical distribution. A short introduction about the anatomy is made. Mandibular fractures are classified by the anatomic regions involved. For this purpose, the mandible is delineated into an array of nine regions identified by letters: the symphysis/parasymphysis region anteriorly, two body regions on each lateral side, combined angle and ascending ramus regions, and finally the condylar and coronoid processes. A precise definition of the demarcation lines between these regions is given for the unambiguous allocation of fractures. Four transition zones allow an accurate topographic assignment if fractures end up in or run across the borders of anatomic regions. These zones are defined between angle/ramus and body, and between body and symphysis/parasymphysis. A fracture is classified as “confined” as long as it is located within a region, in contrast to a fracture being “nonconfined” when it extents to an adjoining region. Illustrations and case examples of mandible fractures are presented to become familiar with the classification procedure in daily routine. PMID:25489388

Biodegradable fixation of mandibular fractures in children: stability and early results.

PubMed

Yerit, Kaan C; Hainich, Sibylle; Enislidis, Georg; Turhani, Dritan; Klug, Clemens; Wittwer, Gert; Ockher, Michael; Undt, Gerhard; Kermer, Christian; Watzinger, Franz; Ewers, Rolf

2005-07-01

The aim of this study was to assess the safety and efficiency of biodegradable self-reinforced (SR-PLDLA) bone plates and screws in open reduction and internal fixation of mandible fractures in children. Thirteen patients (5 female, 8 male; mean age 12 years, range 5-16 years) were operated on various fractures of the mandible (2 symphyseal, 6 parasymphyseal, 4 body, 3 angle, 1 ramus, 2 condylar fractures). The mean follow-up time was 26.4 months (range 10.9-43.4 months). Intermaxillary fixation was applied in cases with concomitant condylar fractures up to 3 weeks. Primary healing of the fractured mandible was observed in all patients. Postoperative complications were minor and transient. The outcome of the operations was not endangered. Adverse tissue reactions to the implants, malocclusion, and growth restrictions did not occur during the observation period. Pediatric patients benefit from the advantages of resorbable materials, especially from faster mobilization and the avoidance of secondary removal operations. Based on these preliminary results, self-reinforced fixation devices are safe and efficient in the treatment of pediatric mandible fractures. However, further clinical investigations are necessary to evaluate the long-term reliability.

The TUNEL assay suggests mandibular regression by programmed cell death during presoldier differentiation in the nasute termite Nasutitermes takasagoensis

NASA Astrophysics Data System (ADS)

Toga, Kouhei; Yoda, Shinichi; Maekawa, Kiyoto

2011-09-01

Termite soldiers are the most specialized caste of social insects in terms of their morphology and function. Soldier development requires increased juvenile hormone (JH) titer and the two molts via a presoldier stage. These molts are accompanied by dramatic morphological changes, including the exaggeration and regression of certain organs. Soldiers of the most apical termitid subfamily Nasutitermitinae possess not only a horn-like frontal tube, called the nasus, for the projection of defensive chemicals from the frontal gland reservoir but also regressed mandibles. Although candidate genes regulating soldier mandibular growth were reported in a relatively basal termite species, the regulatory mechanisms of mandibular regression remain unknown. To clarify these mechanisms, we performed morphological and histological examinations of the mandibles during soldier differentiation in Nasutitermes takasagoensis. Mandibular size reduced dramatically during soldier differentiation, and mandibular regression occurred just prior to the presoldier molt. Spotted TUNEL signals were observed in regressing mandibles of presoldiers, suggesting that the regression involved programmed cell death. Because soldiers of N. takasagoensis possess exaggerated organs (nasus and frontal gland), the present results suggest that JH-dependent regressive mechanisms exist in the mandibles without interfering with the formation of the exaggerated organs.

Immediate Implant Placement in Single-Tooth Molar Extraction Sockets: A 1- to 6-Year Retrospective Clinical Study.

PubMed

Amato, Francesco; Polara, Giorgio

The aim of this study was to investigate the survival rate of implants immediately placed in fresh extraction sockets of molars in the maxilla and mandible with a single-stage procedure. A total of 102 patients were treated, and 107 implants (53 in the maxilla and 54 in the mandible) were placed in a fresh molar extraction socket and connected to a healing abutment. After a mean follow-up of 3 years (range: 1 to 6 years) 1 implant failed, for a cumulative success rate of 99.06% (98.11% for the mandible and 100% for the maxilla). The results of this study support placement of an implant immediately after the extraction of a molar, applying a single-stage procedure.

[Inferior hemiarthroplasty of the temporo-mandibular joint with articulated condylar prosthesis type Stryker].

PubMed

Bucur, A; Dincă, O; Totan, C; Ghită, V

2007-01-01

The optimal reconstruction of the mandible and of the temporo-mandibular joint after mandibular hemi-resection with disarticulation is still controversial in literature. This paperwork presents our experience on four cases in the reconstruction of the mandible together with the inferior arthroplasty of the temporo-mandibular joint, after the resection of extended benign tumors of the mandible, based on fibular free vascularized grafts having attached a Stryker titanium condylar prosthesis reconstructing the inferior segment of the temporo-mandibular joint. Our results for the this technique were excellent, with a functional rehabilitation very close to normal. After reviewing the various techniques and their arguments in literature, with accent on the TMJ reconstruction, we consider this method to be optimal for the reconstruction of mandibular defects in patients with neoplastic conditions.

Application of the Mandible Injury Severity Score to Pediatric Mandibular Fractures.

PubMed

Swanson, Edward W; Susarla, Srinivas M; Ghasemzadeh, Ali; Mundinger, Gerhard S; Redett, Richard J; Tufaro, Anthony P; Manson, Paul N; Dorafshar, Amir H

2015-07-01

The Mandible Injury Severity Score (MISS) has been used to evaluate adult mandibular fractures. The purpose of this study was to evaluate the MISS in a cohort of pediatric patients. This was a retrospective study of pediatric patients treated for mandibular fractures over a 20-year period. Patients were included if they had computed tomographic imaging available for review and had at least 1 post-treatment visit. The primary predictor variable was the MISS. Secondary predictors were demographic and injury-associated factors. The outcome was treatment-associated complications. Descriptive, bivariate, and multiple logistic regression statistics were computed. One hundred sixteen patients with mandibular fractures were identified; 73 (62.9%) met the inclusion criteria. The sample's mean age was 8.5 ± 4.1 years; 44% were girls. Motor vehicle collisions (60%) and falls (15.1%) were the most common mechanisms. More than 50% of patients had an extra-mandibular injury. The mean MISS was 13.5 ± 7.8. Forty-five percent of the sample underwent open reduction and internal fixation. Complications were noted in 20.5% of patients, of which malocclusion was the most common (8.2%). Increasing MISS was associated with complications (P < .001). After controlling for the effects of age, mechanism, cervical spine and skull base injuries, and treatment, patients with an MISS of at least 14 were significantly more likely to have a complication (odds ratio = 4.0; 95% confidence interval, 1.05-15.0; P = .04). In pediatric patients with mandibular fractures, increased severity of injury is associated with complications, even after controlling for the effects of multiple confounders, including open treatment. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Common Avian Infection Plagued the Tyrant Dinosaurs

PubMed Central

Wolff, Ewan D. S.; Salisbury, Steven W.; Horner, John R.; Varricchio, David J.

2009-01-01

Background Tyrannosaurus rex and other tyrannosaurid fossils often display multiple, smooth-edged full-thickness erosive lesions on the mandible, either unilaterally or bilaterally. The cause of these lesions in the Tyrannosaurus rex specimen FMNH PR2081 (known informally by the name ‘Sue’) has previously been attributed to actinomycosis, a bacterial bone infection, or bite wounds from other tyrannosaurids. Methodology/Principal Findings We conducted an extensive survey of tyrannosaurid specimens and identified ten individuals with full-thickness erosive lesions. These lesions were described, measured and photographed for comparison with one another. We also conducted an extensive survey of related archosaurs for similar lesions. We show here that these lesions are consistent with those caused by an avian parasitic infection called trichomonosis, which causes similar abnormalities on the mandible of modern birds, in particular raptors. Conclusions/Significance This finding represents the first evidence for the ancient evolutionary origin of an avian transmissible disease in non-avian theropod dinosaurs. It also provides a valuable insight into the palaeobiology of these now extinct animals. Based on the frequency with which these lesions occur, we hypothesize that tyrannosaurids were commonly infected by a Trichomonas gallinae-like protozoan. For tyrannosaurid populations, the only non-avian dinosaur group that show trichomonosis-type lesions, it is likely that the disease became endemic and spread as a result of antagonistic intraspecific behavior, consumption of prey infected by a Trichomonas gallinae-like protozoan and possibly even cannibalism. The severity of trichomonosis-related lesions in specimens such as Tyrannosaurus rex FMNH PR2081 and Tyrannosaurus rex MOR 980, strongly suggests that these animals died as a direct result of this disease, mostly likely through starvation. PMID:19789646

A novel interference behaviour: invasive wasps remove ants from resources and drop them from a height

PubMed Central

Grangier, Julien; Lester, Philip J.

2011-01-01

This study reports a novel form of interference behaviour between the invasive wasp Vespula vulgaris and the New Zealand native ant Prolasius advenus. By videotaping interactions at bait stations, we found that wasps commonly remove ant competitors from food resources by picking up the workers in their mandibles, flying backward and dropping them unharmed some distance from the food. Both the frequency and the efficiency of the wasp behaviour significantly increased with the abundance of ant competitors. Ant removals were the most common interference events initiated by wasps when ants were numerous, while intraspecific conflicts among wasps were prominent when few ants were present. The ‘ant-dropping’ behaviour emphasizes how asymmetry in body sizes between competitors can lead to a pronounced form of interference, related to asymmetric locomotion modes. PMID:21450726

Telangiectatic osteosarcoma affecting the mandible

PubMed Central

Naik, LR Kumaraswamy; Shetty, Pushparaja; Teerthanath, S; Jagadeesh, H Makannavar

2014-01-01

Osteosarcomas are relatively rare in jaws and maxillomandibular lesions in children are distinctly uncommon. Telengiactic osteosarcomas in jaws are still a very rare variant and till now just 3 cases are reported in English literature. Herein, we report the first case of telangiectatic osteosarcoma occurring in mandible in pediatric patient. Patient was treated by hemimandibulectomy and is free of disease since seven years with regular follow-up. PMID:25364166

Telangiectatic osteosarcoma affecting the mandible.

PubMed

Naik, Lr Kumaraswamy; Shetty, Pushparaja; Teerthanath, S; Jagadeesh, H Makannavar

2014-09-01

Osteosarcomas are relatively rare in jaws and maxillomandibular lesions in children are distinctly uncommon. Telengiactic osteosarcomas in jaws are still a very rare variant and till now just 3 cases are reported in English literature. Herein, we report the first case of telangiectatic osteosarcoma occurring in mandible in pediatric patient. Patient was treated by hemimandibulectomy and is free of disease since seven years with regular follow-up.

Morphological assessment of the mandibular canal trajectory in edentate subjects.

PubMed

Nimigean, Victor; Sîrbu, Valentin Daniel; Nimigean, Vanda Roxana; Bădiţă, Daniela Gabriela; Poll, Alexandru; Moraru, Simona Andreea; Păun, Diana Loreta

2018-01-01

The mandibular canal and its content represent the vital structure, which can complicate dentoalveolar surgical procedures in the posterior region of the mandible. The purpose of the present study was to determine the path the mandibular canal takes in relation to the horizontal and the vertical anatomical reference planes in edentate subjects, in order to minimize the risk of affecting its neurovascular content during various oral surgery procedures. Morphometric evaluations were performed on 12 dried fully edentulous human mandibles and on cone-beam computed tomography (CBCT) cross-sectional images of the mandible, from 20 patients with either partial or complete edentulism. Both methods were utilized, in three target areas (corresponding to the second premolar, to the first molar and to the second molar regions), in order to measure the distance between the mandibular canal and the following reference points: (i) the lateral (buccal) surface of the mandible (MC-BS distance); (ii) the medial (lingual) surface of the mandible (MC-LS distance); (iii) the alveolar surface of the mandible (MC-AS distance). The results were statistically processed in Stata MP/13 software package using analysis of variance (ANOVA) test. The mandibular canal crossed the trabecular bone from the posterior towards the anterior, and from the lingual towards the buccal, reaching the premolar region, distal to the mental foramen, where it was located in the centre of the trabecular bone, main topographic pattern encountered in 27 (84.37%) of the cases. In five (15.63%) of the cases, in the premolar region, the mandibular canal was located near the buccal cortical plate. The mandibular canal descended from the second molar region towards the premolar region, main topographic pattern found in 28 (87.5%) of the cases. In four (12.5%) cases, the mandibular canal had a descending trajectory in the molar regions and it took a slightly ascending course in the premolar region. According to the results, the second molar region represents the highest risk area in the accidental injury to the content of the mandibular canal, during various oral surgery procedures.

Occlusion of artificial teeth in partial dentures in the "chewing center"--first exploratory population-based evaluations.

PubMed

Kordass, B; Ruge, S; Quooss, A; Hugger, A; Mundt, T

2014-01-01

Occlusal performance is a substantial determinant of the quality of dental prosthetic restorations. In the follow-up (SHIP 1) to the Study of Health in Pomerania (SHIP), a representative population of 3300 subjects was studied in the first exploratory evaluation of the occlusion of artificial teeth in the chewing center (first molar region) of partial dentures. A digital analysis of interocclusal records of habitual intercuspation position (ICP) was performed using the Greifswald Digital Analyzing System (GEDAS), a software package that identifies contact points as transparent areas. 562 subjects (280 men aged 61.7 ± 11.9 years and 282 women aged 60.7 ± 10.7 years) had maxillary removable partial dentures (RPDs), and 619 (271 men aged 65.0 ± 11.5 years and 348 women aged 62.4 ± 10.6 years) had mandibular RPDs. Most RPDs were retained with either attachment retainers (11.7% maxilla, 11.7% mandible), cast clasps (38.4% maxilla, 40.7% mandible), telescopes with double crowns (15.7% maxilla, 19.1% mandible), or wrought wire clasps (16.4% maxilla, 8.2% mandible). Some had a combination of different retention elements. The mean number of artificial teeth was 7.8 ± 2.9 in the maxilla and 7.5 ± 3.0 in the mandible. Only the artificial teeth (first molars) in mandibular partial dentures showed differences in the frequency of occlusal contacts between groups (chi-square test). Of these, telescopic crown-retained RPDs had the highest frequency of occlusal contacts (74.4% at tooth 36 and 77.1% at tooth 46), and wrought wire-retained RPDs had the lowest (48.4% at tooth 36 and 45.2% at tooth 46). The results for RPDs with a free-end saddle were comparable and analogous; contact frequencies for those with an interdental saddle did not differ significantly. Notably, the overall frequency of occlusal contacts was greater for tooth 46 (62.9%) than for tooth 36. In conclusion, when replacing teeth in the chewing center, particularly in the mandible, telescopic crown-retained RPDs offer a distinct advantage in terms of occlusal contacts and thus provide better occlusal stability.

The Endo-Distractor for preimplant mandibular regeneration.

PubMed

Krenkel, C; Grunert, I

2009-02-01

A simple practical device for a new technique of vertical distraction osteogenesis was developed. The Endo-Distractor Krenkel was originally intended for the anterior regeneration of highly atrophic mandibles. The Endo-Distractor features several novelties. Placement is made intraosseously in the basal cortical bone. The distraction screw length may be adapted to the depth of chin soft tissues. The quality of anchorage in the basal cortical bone guarantees the stability of the distraction vector. The endobuccal emergence is that of an artificial crown, and does not cause any patient discomfort. The device can easily be removed without secondary surgery. All kinds of implants may be placed after the retention time. This study's objective was to evaluate the use of the Endo-Distractor Krenkel in edentulous patients with highly atrophic mandibles. This new device was used on 18 patients, between January 2000 and September 2004, who were then followed-up for at least 36 months. Mandibular atrophy was measured with a lateral cephalogram, then classified according to Atwood's modified classification. The studied criteria included the amplitude of distraction, its duration, the distractor's lingual tilt, the number and outcome of implants, and complications. The sex ratio was 17 female for one male patient. The mean patient age was 56 years (43 to 66 years). The mean distraction amplitude was 11.3mm (8 to 14 mm). The mean retention time was 186.8 days (37 to 309 days). The distractor's mean lingual tilt was 4.3 degrees (0 to 23 degrees ). Two mandibular fractures occurred 6 weeks after placing the Endo-Distractor. The first one was treated medically, and the second one required removing the Endo-Distractor and osteosynthesis. An average of four interforaminal implants were placed for a total of 24 Brånemark and 51 Straumann implants. Four implants were lost in a patient due to infection. All other implants were osseointegrated. No bone loss was detected at follow-up after functional loading. These results show that alveolar distraction is possible on severely atrophic mandibles. The quality of bone and gum reconstruction is satisfactory both for functional and esthetic results. Surgical difficulty and rate of complications were lower than with conventional distraction techniques.

The Neandertals of northeastern Iberia: new remains from the Cova del Gegant (Sitges, Barcelona).

PubMed

Quam, Rolf; Sanz, Montserrat; Daura, Joan; Robson Brown, Kate; García-González, Rebeca; Rodríguez, Laura; Dawson, Heidi; Rodríguez, Rosa Flor; Gómez, Sandra; Villaescusa, Lucía; Rubio, Ángel; Yagüe, Almudena; Ortega Martínez, María Cruz; Fullola, Josep Maria; Zilhão, João; Arsuaga, Juan Luis

2015-04-01

The present study describes a new juvenile hominin mandible and teeth and a new juvenile humerus from level V of the GP2 gallery of Cova del Gegant (Spain). The mandible (Gegant-5) preserves a portion of the right mandibular corpus from the M1 distally to the socket for the dc mesially, and the age at death is estimated as 4.5-5.0 years. Gegant-5 shows a single mental foramen located under the dm1/dm2 interdental septum, a relatively posterior placement compared with recent hominins of a similar developmental age. The mental foramen in Gegant-5 is also placed within the lower half of the mandibular corpus, as in the previously described late adolescent/adult mandible (Gegant-1) from this same Middle Paleolithic site. The Gegant-5 canine shows pronounced marginal ridges, a distal accessory ridge, and a pronounced distolingual tubercle. The P3 shows a lingually-displaced protoconid cusp tip and a distal accessory ridge. The P4 shows a slightly asymmetrical crown outline, a continuous transverse crest, a mesially placed metaconid cusp tip, a slight distal accessory ridge, and an accessory lingual cusp. The M1 shows a Y5 pattern of cusp contact and a well-developed and deep anterior fovea bounded posteriorly by a continuous midtrigonid crest. Gegant-4 is the distal portion of a left humerus from a juvenile estimated to be between 5 and 7 years old at death. The specimen shows thick cortical bone. Although fragmentary, the constellation of morphological and metric features indicates Neandertal affinities for these specimens. Their spatial proximity at the site and similar ages at death suggest these remains may represent a single individual. The addition of these new specimens brings the total number of Neandertal remains from the Cova del Gegant to five, and this site documents the clearest evidence for Neandertal fossils associated with Middle Paleolithic stone tools in this region of the Iberian Peninsula. Copyright © 2015 Elsevier Ltd. All rights reserved.

Serotonin precursor (5-hydroxytryptophan) causes substantial changes in the fighting behavior of male crickets, Gryllus bimaculatus.

PubMed

Dyakonova, V E; Krushinsky, A L

2013-07-01

This study demonstrates that injection of the serotonin precursor 5-HTP causes substantial changes in the behavioral state, fighting behavior and ability to establish winner-loser relationships in male crickets (Gryllus bimaculatus). The characteristic features of 5-HTP-treated crickets include an elevated posture, enhanced general activity, longer duration of fighting, enhanced rival singing and a decreased ability to produce a clear fight loser. In addition, 5-HTP-treated males showed a slightly delayed latency to spread their mandibles, a decreased number of attacks and an equal potential to win in comparison to controls (physiological solution-treated males). The obtained results imply a significant role for serotonin in the regulation of social status-related behaviors in G. bimaculatus. Specifically, these data indicate that a decrease in serotonergic activity may be functionally important for the control of loser behavior and that some behavioral features of dominant male crickets are likely to be connected with the activation of the serotonergic system.

Amyloid-producing odontogenic tumour (calcifying epithelial odontogenic tumour) in the mandible of a Bengal tiger (Panthera tigris tigris).

PubMed

Kang, M-S; Park, M-S; Kwon, S-W; Ma, S-A; Cho, D-Y; Kim, D-Y; Kim, Y

2006-01-01

A 13-year-old male tiger (Panthera tigris tigris) had a marked mandibular swelling noticed 12 months earlier and associated with progressive anorexia and weight loss. Radiological and post-mortem examination revealed a mass (13x15 cm) which was firm and poorly defined, with destruction of the adjacent bone tissue. Histologically, the mass was poorly demarcated, with infiltrative growth, and composed of nests, cords and islands of epithelial cells with characteristic basal cell features. Also observed were extensive squamous metaplasia, ghost cells, stellate reticulum, and fibroblastic connective tissue stroma containing inflammatory cells. A prominent feature of this tumour consisted of abundant nodular deposits of congophilic amyloid-like material with partial mineralization (Liesegang rings). Immunohistochemically, the neoplastic cells and the amyloid-like material were positive for pancytokeratin and negative for vimentin. The findings supported the diagnosis of an amyloid-producing odontogenic tumour (APOT), also known as calcifying epithelial odontogenic tumour in man and animals.

Assessing the Amount of Interdental Bone in Posterior Areas of the Mandible for Placing Orthodontic Mini-Implants

PubMed Central

Esfahanizadeh, Nasrin; Shahraki, Damoun; Daneshparvar, Hamidreza; Talaei Pour, Ahmad Reza; Saghiri, Mohammad Ali; Sheibaninia, Ahmad; Rashtak, Shadab

2013-01-01

Objective : The aim of this study was to assess the amount of interdental bone in posterior areas of the mandible for placing orthodontic mini-implants to provide and control anchorage in orthodontic treatment. Materials and Methods : The amount of interdental bone in areas between the second premolars and first molars, first and second molars on the right and left sides of the mandible were determined in fifty patients by RVG using periapical radiographs. The images were assessed using Cygnus Media Software to determine the mesio-distal width of the interdental bone, starting at the crest of the alveolar bone (2 mm below the CEJ) every one millimeter up to 12 mm from the CEJ. The actual amount of interdental bone and the effect of related factors were assessed using chi-square test at a 95% confidence interval. Results : The minimum desired interdental bone width for placing mini-implants, 3 mm from the CEJ, between the second premolar and first molar and the first and second molars of the mandible on both sides were significantly different (p<0.01): 1.8 mm (31%) more apical in the area between the second premolar and the first molar. There was also a statistically significant difference between the areas under study on the right side (p<0.002), which was 2.2 mm (44%) more apical in the area of the second premolar and the first molar. Conclusion : The most secure site for placing orthodontic mini-implants in the mandible is between the first and second molars at the height of 5.8 mm from the CEJ. PMID:25512751

Facial skeleton asymmetry and its relationship to mastication in the Early Medieval period (Great Moravian Empire, Mikulčice, 9th-10th century).

PubMed

Ibrová, Alexandra; Dupej, Ján; Stránská, Petra; Velemínský, Petr; Poláček, Lumír; Velemínská, Jana

2017-12-01

The aim of this study was to analyse the relationship of mastication and directional asymmetry (DA) of upper facial skeleton in Early Medieval sample from the Mikulčice settlement (Czech Republic). The settlement is divided into two burial areas of presumably different socioeconomic status: the castle and the sub-castle. The material consisted of 193 individuals (125 castle, 68 sub-castle). The relationship of facial skeleton DA and mastication was analysed by examining tooth wear and mandibular shape by means of 3D geometric morphometrics. Tooth wear of premolars and molars was evaluated using appropriate scoring systems. 3D coordinates of 35 mandibular landmarks were scanned using MicroScribe G2X digitizing system. The results did not reveal any significant differences in tooth wear DA or mandible DA values between burial areas or sexes. Mandibular shape, however, differed significantly between burial areas and sexes. Directional changes of mandibular landmarks supported a right chewing side preference in the sample. Significant relationship between upper facial skeleton DA and mandible DA was recorded. Differences in subsistence between burial areas and sexes did not translate into differences in mandible DA and dental wear. However, mandibular shape analysis revealed prominence of areas affected by masticatory muscles in individuals from the castle. Higher consumption of tough material, such as meat, has been proposed as possible explanation. The right side was found to be preferential for chewing. The relationship between upper facial skeleton DA and mandible DA was concluded to be the result of the compensatory and adaptive function of mandible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adaptation of BAp crystal orientation to stress distribution in rat mandible during bone growth

NASA Astrophysics Data System (ADS)

Nakano, T.; Fujitani, W.; Ishimoto, T.; Umakoshi, Y.

2009-05-01

Biological apatite (BAp) c-axis orientation strongly depends on stress distribution in vivo and tends to align along the principal stress direction in bones. Dentulous mandible is subjected to a complicated stress condition in vivo during chewing but few studies have been carried out on the BAp c-axis orientation; so the adaptation of BAp crystal orientation to stress distribution was examined in rat dentulous mandible during bone growth and mastication. Female SD rats 4 to 14 weeks old were prepared, and the bone mineral density (BMD) and BAp crystal orientation were analyzed in a cross-section of mandible across the first molar focusing on two positions: separated from and just under the tooth root on the same cross-section perpendicular to the mesiodistal axis. The degree of BAp orientation was analyzed by a microbeam X-ray diffractometer using Cu-Kα radiation equipped with a detector of curved one-dimensional PSPC and two-dimensional PSPC in the reflection and transmission optics, respectively. BMD quickly increased during bone growth up to 14 weeks, although it was independent of the position from the tooth root. In contrast, BAp crystal orientation strongly depended on the age and the position from the tooth root, even in the same cross-section and direction, especially along the mesiodistal and the biting axes. With increased biting stress during bone growth, the degree of BAp orientation increased along the mesiodistal axis in a position separated from the tooth root more than that near the tooth root. In contrast, BAp preferential alignment clearly appeared along the biting axis near the tooth root. We conclude that BAp orientation rather than BMD sensitively adapts to local stress distribution, especially from the chewing stress in vivo in the mandible.

Can different occlusal positions instantaneously impact spine and body posture? : A pilot study using rasterstereography for a three-dimensional evaluation.

PubMed

März, Karoline; Adler, Werner; Matta, Ragai-Edward; Wolf, Linda; Wichmann, Manfred; Bergauer, Bastian

2017-05-01

Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions. Optical body scans were collected for 44 subjects, using the Diers formetric 4D system, for seven different mandible positions. In total, ten spinal and body posture parameters were assessed (trunk inclination, trunk imbalance, pelvic tilt, pelvic torsion, fleche cervicale, fleche lombaire, kyphotic angle, lordotic angle, surface rotation, and lateral deviation) for each mandible position and compared with scans performed with habitual intercuspation (HIC). Significant body posture deviations were found for the fleche cervicale (position of the mandible: right eccentrically), fleche lombaire (positions of the mandible: physiologic rest position, cotton rolls on both sides, bite elevation 1 mm), and the kyphotic angle (positions of the mandible: cotton rolls on both sides, right eccentrically). No other significant differences were detected. Data for the parameters that varied with different dental occlusions generated high standard deviations. Therefore, within the limitations of this pilot study, we could not conclusively associate dental occlusion to an instantaneous impact on the tested parameters. The posture changes that we detected could also have arisen from individual neuromuscular compensation; a possibility that must now be ruled-in, or out, by further research studies with a higher number of subjects.

Use of an intraoperative navigation system for retrieving a broken dental instrument in the mandible: a case report.

PubMed

Sukegawa, Shintaro; Kanno, Takahiro; Shibata, Akane; Matsumoto, Kenichi; Sukegawa-Takahashi, Yuka; Sakaida, Kyosuke; Furuki, Yoshihiko

2017-01-15

A fracture of root canal instruments, with a fractured piece protruding beyond the apex, is a troublesome incident during an endodontic treatment. Locating and retrieving them represents a challenge to maxillofacial surgeons because it is difficult to access due to the proximity between the foreign body and vital structures. Although safe and accurate for surgery, radiographs and electromagnetic devices do not provide a precise three-dimensional position. In contrast, computer-aided navigation provides a correlation between preoperatively collected data and intraoperatively encountered anatomy. However, using a navigation system for mandible treatment is difficult as the mobile nature of the mandible complicates its synchronization with the preoperative imaging data during surgery. This report describes a case of a dental instrument breakage in the mandible during an endodontic treatment for a restorative dental procedure in a 65-year-old Japanese woman. The broken dental instrument was removed using a minimally invasive approach with a surgical navigation system and an interocclusal splint for a stable, identically repeatable positioning of the mandible. Using the three-dimensional position of the navigation probe, a location that best approximated the most anterior extent of the fragment was selected. A minimally invasive vestibular incision was made at this location, a subperiosteal reflection was performed, and the foreign body location was confirmed using a careful navigation system. The instrument was carefully visualized and extruded from the apical to the tooth crown side and was then removed using mosquito forceps through the medullary cavity of the crown side of the tooth. Follow-up was uneventful; her clinical course was good. The use of a surgical navigation system together with an interocclusal splint enabled the retrieval of a broken dental instrument in a safe and minimally invasive manner without damaging the surrounding vital structures.

Exploring Biological and Geological Age-related Changes through Variations in Intra- and Intertooth Proteomes of Ancient Dentine.

PubMed

Procopio, Noemi; Chamberlain, Andrew T; Buckley, Michael

2018-03-02

Proteomic analyses are becoming more widely used in archeology not only due to the greater preservation of proteins in ancient specimens than DNA but also because they can offer different information, particularly relating to compositional preservation and potentially a means to estimate biological and geological age. However, it remains unclear to what extent different burial environments impact these aspects of proteome decay. Teeth have to date been much less studied than bone but are ideal to explore how proteins decay with time due to the negligible turnover that occurs in dentine relative to bone. We investigated the proteome variability and deamidation levels of different sections of molar teeth from archeological bovine mandibles as well as their mandibular bone. We obtained a greater yield of proteins from the crown of the teeth but did not find differences between the different molars analyzed within each mandible. We also obtained the best variety of protein from a well-preserved mandible that was not the youngest one in terms of chronological age, showing the influence of the preservation conditions on the final proteomic outcome. Intriguingly, we also noticed an increase in abundance levels of fetuin-A in biologically younger mandibles as reported previously, but the opposite trend in tooth dentine. Interestingly, we observed higher glutamine deamidation levels in teeth from the geologically oldest mandible despite it being the biologically youngest specimen, showing that the archeological age strongly impacts on the level of deamidations observed, much more so than biological aging. This indicates that the glutamine deamidation ratio of selected peptides may act as a good predictor of the relative geochronological age of archeological specimens.

Mandibular Fractures in Iraq: An Epidemiological Study

PubMed Central

Bede, Salwan

2014-01-01

The purpose of this study was to evaluate the epidemiological characteristics of the mandibular fractures relating to gender, age, the etiology of injury, and the rendered treatment modalities and complications. The data of the patients who sustained mandibular fractures were retrieved and were analyzed retrospectively, and based on these data a descriptive analysis was conducted. A total of 112 patients were included in this study; the most common cause was road traffic accidents (RTAs) followed by assaults and missile injuries. The most frequently involved age group was 11 to 20 years, treatment modalities included conservative, closed reduction and indirect fixation, and open reduction and internal fixation (ORIF) in 11.6, 79.5, and 8.9% of the cases, respectively. Most of the major complications were injury related. This study showed RTAs to be the most frequent cause followed by assaults, it also showed that a high percentage of assault victims were females mainly of low socioeconomic status. Another distinguishing feature in this study was the high incidence of missile injuries in the form of bullets and blasts. Closed reduction still has an important role in the treatment of fractures of mandible especially when the necessary equipments for ORIF are not readily available. A higher complication rate was observed in patients diagnosed with multiple and comminuted fractures as well as those caused by violence in the form of missile and assault injuries. PMID:25709754

Computer-assisted resection and reconstruction of bilateral osteoradionecrosis of the mandible using 2 separate flaps prepared from a single fibula.

PubMed

Chen, Rui; Zhang, Han-Qing; Huang, Zi-Xian; Li, Shi-Hao; Zhang, Da-Ming; Huang, Zhi-Quan

2018-03-07

Osteoradionecrosis of the mandible is a late radiation-induced complication, which is a major concern in survivors of head and neck cancer. In this study, we present a case of a patient with nasopharyngeal carcinoma who developed extensive bilateral osteoradionecrosis of the ascending ramus of the mandible. After preoperative virtual surgical planning, the obtained data were used to fabricate patient-specific cutting templates. The bilateral mandibular defects were reconstructed using 2 separate flaps prepared from a single fibula. Both defects were successfully reconstructed, and satisfactory aesthetic and functional results were achieved. Bilateral mandibular osteoradionecrosis can be managed with virtual surgical planning, and the defects can be reconstructed using 2 separate flaps prepared from a single fibula. Copyright © 2018 Elsevier Inc. All rights reserved.

Mandible shape and dwarfism in squirrels (Mammalia, Rodentia): interaction of allometry and adaptation

NASA Astrophysics Data System (ADS)

Hautier, Lionel; Fabre, Pierre-Henri; Michaux, Jacques

2009-06-01

Squirrels include several independent lineages of dwarf forms distributed into two ecological groups: the dwarf tree and flying squirrels. The mandible of dwarf tree squirrels share a highly reduced coronoid process and a condylar process drawn backwards. Dwarf flying squirrels on the other hand, have an elongated coronoid process and a well-differentiated condylar process. To interpret such a difference, Elliptic Fourier Transform was used to evaluate how mandible shape varies with dwarfism in sciurids. The results obtained show that this clear-cut difference cannot be explained by a simple allometric relationship in relation with size decrease. We concluded that the retention of anteriorly positioned eye sockets, in relation with distance estimation, allowed the conservation of a well-differentiated coronoid process in all flying species, despite the trend towards its reduction observed among sciurids as their size decreases.

Mucormycosis of Mandible with Unfavorable Outcome

PubMed Central

Oswal, Nitin Prakash; Gadre, Pushkar Kiran; Sathe, Prachee; Gadre, Kiran Shrikrishna

2012-01-01

Mucormycosis is a fulminant fungal infection that occurs most often in diabetic and immunocompromised individuals. Our patient, with uncontrolled diabetes mellitus and multiple systemic disorders, developed postextraction mucormycosis of mandible, an extremely rare complication. An initial clinical and radiographic diagnosis of mandibular osteomyelitis was made and the lesion was treated medically and surgically with curettage and saucerisation. The specimen was sent for histopathological evaluation, which showed necrotic area containing broad aseptate fungal hyphae with right angle branching consistent with mucormycosis. The patient succumbed to multipleorgan failure secondary to septicemia. The disease is usually fatal with a poor survival rate; there is still paucity of literature on the definitive management of this disease involving the mandible. This paper emphasizes the need for correction of underlying immunodeficiency and early diagnosis with aggressive multimodality treatment approach to offer the best chance of survival. PMID:22779014

Mucormycosis of mandible with unfavorable outcome.

PubMed

Oswal, Nitin Prakash; Gadre, Pushkar Kiran; Sathe, Prachee; Gadre, Kiran Shrikrishna

2012-01-01

Mucormycosis is a fulminant fungal infection that occurs most often in diabetic and immunocompromised individuals. Our patient, with uncontrolled diabetes mellitus and multiple systemic disorders, developed postextraction mucormycosis of mandible, an extremely rare complication. An initial clinical and radiographic diagnosis of mandibular osteomyelitis was made and the lesion was treated medically and surgically with curettage and saucerisation. The specimen was sent for histopathological evaluation, which showed necrotic area containing broad aseptate fungal hyphae with right angle branching consistent with mucormycosis. The patient succumbed to multipleorgan failure secondary to septicemia. The disease is usually fatal with a poor survival rate; there is still paucity of literature on the definitive management of this disease involving the mandible. This paper emphasizes the need for correction of underlying immunodeficiency and early diagnosis with aggressive multimodality treatment approach to offer the best chance of survival.

Needle in the external auditory canal: an unusual complication of inferior alveolar nerve block.

PubMed

Ribeiro, Leandro; Ramalho, Sara; Gerós, Sandra; Ferreira, Edite Coimbra; Faria e Almeida, António; Condé, Artur

2014-06-01

Inferior alveolar nerve block is used to anesthetize the ipsilateral mandible. The most commonly used technique is one in which the anesthetic is injected directly into the pterygomandibular space, by an intraoral approach. The fracture of the needle, although uncommon, can lead to potentially serious complications. The needle is usually found in the pterygomandibular space, although it can migrate and damage adjacent structures, with variable consequences. The authors report an unusual case of a fractured needle, migrating to the external auditory canal, as a result of an inferior alveolar nerve block. Copyright © 2014 Elsevier Inc. All rights reserved.

Surgical treatment and a unique management of rostral mandibular fracture with cerclage wire in a horse.

PubMed

Naddaf, Hadi; Sabiza, Soroush; Kavosi, Narges

2015-01-01

A 3-year-old Arabian colt was presented for a major gingiva wound at the right rostral part of mandible. After clinical assessments, rostral mandibular fracture was determined. Stabilization of fractured region was achieved via cerclage wire application under general anesthesia. Fixation wires were left in place for 6 weeks. A 3 -month follow up revealed complete fracture healing. The purpose of this case report was to give clinical information about rostral mandibular fractures and treatment of these fractures and nutrition protocol in a horse, as this fracture is of the most common type of jaw fracture sustained by young horses.

Simple bone cyst of mandible mimicking periapical cyst

PubMed Central

HS, Charan Babu; Rai, Bhagawan Das; Nair, Manju A.; Astekar, Madhusudan S.

2012-01-01

Simple bone cysts (SBC) are pseudocysts occurring less commonly in the maxillofacial region. The uncertain and unclear etiopathogenesis led to numerous synonyms to refer this particular cyst. These cysts are devoid of an epithelial lining and are usually empty or contain blood or straw-colored fluid. In jaws initially it mimics a periapical cyst and later can lead to cortical bone expansion warranting for radical approach, which is seldom required. SBC is predominantly diagnosed in first two decades of life. Here we report a case of solitary bone cyst mimicking a periapical cyst of a mandibular molar in a 37-year-old patient. PMID:24765458

Epidemiological Evaluation of Head and Neck Sarcomas in Iran (the Study of 105 Cases Over 13 Years).

PubMed

Alishahi, Batoul; Kargahi, Neda; Homayouni, Solmaz

2015-08-01

Head and neck sarcomas are exceedingly rare and they include 4% - 10% of all sarcomas and less than 1% of all neoplasm of head and neck. The aim of this study is to evaluate the epidemiological characteristics of head and neck sarcomas of patients in Isfahan, Iran. In this retrospective study, from the 16000 patients whose files were evaluated, the total number of 105 head and neck sarcomas were collected. They were evaluated with due attention to age, gender of the patients and the most common location of the lesion. From the total number of 105 (0.6%) patients with sarcomas, 56 were men (53.33%) and 49 women (46.66%). The most common head and neck sarcomas among this population were Osteosarcoma (32 cases, 30.47%), Chondrosarcoma (14 cases, 13.33%), and Ewing sarcoma (11 cases, 10.47%).The most common soft tissue sarcoma was Rabdomiosarcoma. Mandible was the most common location for these lesions. In this study, the hard tissue sarcomas were more prevalent than soft tissue ones. Hence, special attention should be paid to the patients when being diagnosed.

Andy Gump Fracture of the Mandible in a Pediatric Patient.

PubMed

Mulinari-Santos, Gabriel; Lima, Valthierre Nunes; Palacio-Muñoz, Xiomara Mónica Johanna; Oliva, André Hergesel de; Momesso, Gustavo Antonio Correa; Polo, Tárik Ocon Braga; Souza, Francisley Ávila; Garcia-Júnior, Idelmo Rangel; Faverani, Leonardo Perez

2017-10-01

The mandibular fractures in pediatric patients are rare, and they can need a fast and safe treatment. We present a case of a pediatric patient with "Andy Gump" fracture, resulting in a retrognathic mandible, distress to breathe, and functional discomfort to the patient caused by a cycling accident. The treatment was successful with the fast release of airway path and use of titanium plates to fix the fracture.

Irradiation autogenous mandibular grafts in primary reconstructions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamaker, R.C.

1981-07-01

The procedure, irradiated mandibular autografts, for primary reconstruction, is presented with an immediate success rate of 88%. Eight cases have undergone primary mandibular reconstruction with the tumorous mandible irradiated to 10,000 rads in a single dose. The longest follow-up is 2 3/4 years. The autograft has proven to be an ideal implant. Major resections of the mandible in conjunction with large myocutaneous flaps have been reconstructed utilizing this implant.

Titanium Mesh Shaping and Fixation for the Treatment of Comminuted Mandibular Fractures.

PubMed

Dai, Jiewen; Shen, Guofang; Yuan, Hao; Zhang, Wenbin; Shen, Shunyao; Shi, Jun

2016-02-01

Treating comminuted mandibular fractures remains a challenge. In this study, we used titanium mesh to treat comminuted mandibular fractures. Nine patients with traumatically comminuted mandibular fractures who received open reduction and internal stable fixation with titanium mesh were retrospectively reviewed. Open reduction-internal stable fixation was performed 7 to 10 days after primary debridement of the facial trauma. After the fractured mandible and the displaced fragments were reduced, the titanium mesh was reshaped according to the morphology of the mandible, and the reduced bone fragments were fixed with the reshaped titanium mesh and screws. Then, the surgical effects were evaluated during routine follow-up. Most of the displaced fragments were preserved and exhibited a favorable shaping ability in restoring the morphology of the mandible during surgery. No intraoperative complications were encountered. In addition, all patients were infection free, with no obvious resorption in the fixed fragments after surgery. The mandible also exhibited favorable morphology and offered sufficient bone mass for dental implantation or a denture prosthesis. We conclude that titanium mesh shaping and fixation can effectively treat comminuted mandibular fractures with little bone fragment loss, little soft tissue exposure, a low infection rate, and favorable mandibular morphology. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Use of mini dental implants in ectodermal dysplasia children: follow-up of three cases.

PubMed

Sfeir, E; Nassif, N; Moukarzel, C

2014-07-01

Ectodermal dysplasia is a hereditary genodermatosis characterised by a congenital defect of ectodermal structures, causing tooth malformations and anomalies. Implantology has become accepted in these subjects. However cases are often complicated by a reduction in the size of the alveolar process, making the insertion of conventional implants difficult without bone grafting. The reduced diameter of mini-implants and their ease of insertion provide an interesting solution in supporting removable or fixed prosthesis. The purpose of this paper is to report the follow-up of three cases of children (11-12 year- old) with ectodermal dysplasia in which mini-implants were used to support the prostheses. In the first case, two mini-implants were inserted into the anterior part of the mandible for stabilising a removable denture (2 years follow-up). In the other two cases, mini- implants were inserted in the maxilla and mandible to replace missing front teeth with fixed prostheses. Patients were called for follow- up every 6 months: in the sencod case follow-up lasted 4 years in the mandible and 2 years in the maxilla; in the third case, 2 years in the maxilla and 1 year in the mandible. The use of mini-implants in children with ectodermal dysplasia can enhance aesthetics, and functional and psychosocial development.

Occurrence of the Retromolar Foramen in Dry Mandibles of South-Eastern Part of India: A Morphological Study with Review of the Literature

PubMed Central

Potu, Bhagath Kumar; Kumar, Vinod; Salem, Abdel-Halim; Abu-Hijleh, Marwan

2014-01-01

The retromolar foramen (RMF) is a rare anatomical structure situated in the retromolar fossa behind the third molar tooth. When it is present, the foramen is connected with the mandibular canal and is believed to transmit neurovascular structures that provide accessory source to the mandibular molars and the buccal area. Reports from the literature show that the presence of RMF could pose a challenge in complete blockage of the inferior alveolar nerve during mandibular surgeries. We report the incidence of retromolar foramen from ninety-four dry mandibles of south-eastern part of Karnataka State, India. The foramen was observed in 11 mandibles out of 94 included in the study (11.7%). In three mandibles, the foramen was present bilaterally (3.2%) and in three it was on the left side (3.2%) and in five it was on the right side (5.3%). For the first time, we also measured the dimensions of the retromolar area and distance of the foramen from third molar tooth to understand its risks during the surgical extraction of the lower third molar tooth. A thorough review of the literature has also been done to compare the present findings with the studies reported from the various populations. PMID:25489487

Implant-supported rehabilitation after treatment of atrophic mandibular fractures: report of two cases.

PubMed

Oliveira, Leandro Benetti de; Gabrielli, Marisa Aparecida Cabrini; Gabrielli, Mario Francisco Real; Pereira-Filho, Valfrido Antonio Pereira

2015-12-01

The objective of this article is to present options of rehabilitation with dental implants in two cases of severely atrophic mandibles (<10 mm) after rigid internal fixation of fractures. Two patients who sustained fractures in severely atrophic mandibles with less than 10 mm of bone height were treated by open reduction and internal fixation through a transcervical access. Internal fixation was obtained with 2.4-mm locking reconstruction plates. The first patient presented satisfactory bone height at the area between the mental foramens and after 2 years, received flapless guided implants in the anterior mandible and an immediate protocol prosthesis. The second patient received a tent pole iliac crest autogenous graft after 2 years of fracture treatment and immediate implants. After 5 months, a protocol prosthesis was installed in the second patient. In both cases, the internal fixation followed AO principles for load-bearing osteosynthesis. Both prosthetic devices were Branemark protocol prosthesis. The mandibular reconstruction plates were not removed. Both patients are rehabilitated without complications and satisfied with esthetic and functional results. With the current techniques of internal fixation, grafting, and guided implants, the treatment of atrophic mandible fractures can achieve very good results, which were previously not possible.

Mood-induced variations of mandible and tongue postures.

PubMed

Bourdiol, P; Mishellany-Dutour, A; Peyron, M-A; Woda, A

2013-06-01

Twelve young adults in a good general health were observed during habitual posture of tongue and jaw in different emotional conditions induced by watching three video sequences. The position of the mandible was tracked by the displacements of an electromagnetic sensor glued to the chin. The tongue-to-palate distance was obtained by 2-D location of three electromagnetic sensors placed on the tongue upper midline surface. Head displacements were evaluated with a sensor fixed to an upper central incisor and were subtracted from corresponding displacements of tongue and chin sensors to obtain the real tongue and mandible positions during continuous recording sequences. Emotional conditioning by a fear movie influenced the vertical position of the mandible: the mean interarch distances during the fear movie (2·34 ± 0·24 mm) were significantly different from those measured during the tender (3·13 ± 0·35) and neutral (3·42 ± 0·80) movies, respectively (anova repeated measure, SNK; P < 0·05). anova repeated measure indicated that the tongue-to-palate distance differed significantly when the subjects were watching the conditioning movies (P = 0·003), the tip of the tongue taking a lower position during the fear movie than during the tender and neutral movies. © 2013 John Wiley & Sons Ltd.

Dental application of novel finite element analysis software for three-dimensional finite element modeling of a dentulous mandible from its computed tomography images.

PubMed

Nakamura, Keiko; Tajima, Kiyoshi; Chen, Ker-Kong; Nagamatsu, Yuki; Kakigawa, Hiroshi; Masumi, Shin-ich

2013-12-01

This study focused on the application of novel finite-element analysis software for constructing a finite-element model from the computed tomography data of a human dentulous mandible. The finite-element model is necessary for evaluating the mechanical response of the alveolar part of the mandible, resulting from occlusal force applied to the teeth during biting. Commercially available patient-specific general computed tomography-based finite-element analysis software was solely applied to the finite-element analysis for the extraction of computed tomography data. The mandibular bone with teeth was extracted from the original images. Both the enamel and the dentin were extracted after image processing, and the periodontal ligament was created from the segmented dentin. The constructed finite-element model was reasonably accurate using a total of 234,644 nodes and 1,268,784 tetrahedral and 40,665 shell elements. The elastic moduli of the heterogeneous mandibular bone were determined from the bone density data of the computed tomography images. The results suggested that the software applied in this study is both useful and powerful for creating a more accurate three-dimensional finite-element model of a dentulous mandible from the computed tomography data without the need for any other software.

Prediction of age and gender using digital radiographic method: A retrospective study.

PubMed

Poongodi, V; Kanmani, R; Anandi, M S; Krithika, C L; Kannan, A; Raghuram, P H

2015-08-01

To investigate age, sex based on gonial angle, width and breadth of the ramus of the mandible by digital orthopantomograph. A total of 200 panoramic radiographic images were selected. The age of the individuals ranged between 4 and 75 years of both the gender - males (113) and females (87) and selected radiographic images were measured using KLONK image measurement software tool with linear, angular measurement. The investigated radiographs were collected from the records of SRM Dental College, Department of Oral Medicine and Radiology. Radiographs with any pathology, facial deformities, if no observation of mental foramen, congenital deformities, magnification, and distortion were excluded. Mean, median, standard deviation, derived to check the first and third quartile, linear regression is used to check age and gender correlation with angle of mandible, height and width of the ramus of mandible. The radiographic method is a simpler and cost-effective method of age identification compared with histological and biochemical methods. Mandible is strongest facial bone after the skull, pelvic bone. It is validatory to predict age and gender by many previous studies. Radiographic and tomographic images have become an essential aid for human identification in forensic dentistry forensic dentists can choose the most appropriate one since the validity of age and gender estimation crucially depends on the method used and its proper application.

Vertical augmentation of the posterior atrophic mandible by interpositional grafts in a split-mouth design: a human tomography evaluation pilot study.

PubMed

Domingues, Eduardo Pinheiro; Ribeiro, Rafael Fernandes; Horta, Martinho Campolina Rebello; Manzi, Flávio Ricardo; Côsso, Maurício Greco; Zenóbio, Elton Gonçalves

2017-10-01

Using computed tomography, to compare vertical and volumetric bone augmentation after interposition grafting with bovine bone mineral matrix (GEISTLICH BIO-OSS ® ) or hydroxyapatite/tricalcium phosphate (STRAUMANN ® BONECERAMIC) for atrophic posterior mandible reconstruction through segmental osteotomy. Seven patients received interposition grafts in the posterior mandible for implant rehabilitation. The computed tomography cone beam images were analysed with OsiriX Imaging Software 6.5 (Pixmeo Geneva, Switzerland) in the pre-surgical period (T0), at 15 days post-surgery (T1) and at 180 days post-surgery (T2). The tomographic analysis was performed by a single trained and calibrated radiologist. Descriptive statistics and nonparametric methods were used to analyse the data. There was a significant difference in vertical and volume augmentation with both biomaterials using the technique (P < 0.05). There were no significant differences (P > 0.05) in volume change of the graft, bone volume augmentation, or augmentation of the maximum linear vertical distance between the two analysed biomaterials. The GEISTLICH BIO-OSS ® and STRAUMANN ® BONECERAMIC interposition grafts exhibited similar and sufficient dimensional stability and volume gain for short implants in the atrophic posterior mandible. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Biting and chewing in overdentures, full dentures, and natural dentitions.

PubMed

Fontijn-Tekamp, F A; Slagter, A P; Van Der Bilt, A; Van 'T Hof, M A; Witter, D J; Kalk, W; Jansen, J A

2000-07-01

It has been suggested that the provision of dental implants can improve the oral function of subjects with severely resorbed mandibles, possibly restoring function to the level experienced by satisfied wearers of conventional complete dentures. Nevertheless, a quantitative comparison has never been made and can be drawn from the literature only with difficulty, since studies differ greatly in methodology. To make such a comparison, we measured bite force and chewing efficiency by using identical methods in subjects with overdentures, complete full dentures, and natural dentitions. Our results indicated that bite forces achieved with overdentures on dental implants were between those achieved with artificial and natural dentitions. Chewing efficiency was significantly greater than that of subjects with full dentures (low mandible), but was still lower than that of subjects with full dentures (high mandible) and overdentures on bare roots. Differences in the height of the mandible revealed significant differences in chewing efficiency between the two full-denture groups. Furthermore, subjects with a shortened dental arch exerted bite forces similar to those of subjects with a complete-natural dentition, but their chewing efficiency was limited due to the reduced occlusal area. For all groups combined, a significant correlation was found between maximum bite force and chewing efficiency. Nearly half of the variation in chewing efficiency was explained by bite force alone.

Chewing efficiency and maximum bite force with different attachment systems of implant overdentures: a crossover study.

PubMed

Elsyad, Moustafa Abdou; Khairallah, Ahmed Samir

2017-06-01

This crossover study aimed to evaluate and compare chewing efficiency and maximum bite force (MBF) with resilient telescopic and bar attachment systems of implant overdentures in patients with atrophied mandibles. Ten participants with severely resorbed mandibles and persistent denture problems received new maxillary and mandibular conventional dentures (control, CD). After 3 months of adaptation, two implants were inserted in canine region of the mandible. In a quasi-random method, overdentures were connected to the implants with either bar overdentures (BOD) or resilient telescopic overdentures (TOD) attachment systems. Chewing efficiency in terms of unmixed fraction (UF) was measured using chewing gum (after 5, 10, 20, 30 and 50 strokes), and MBF was measured using a bite force transducer. Measurements were performed 3 months after using each of the following prostheses: CD, BOD and TOD. Chewing efficiency and MBF increased significantly with BOD and TOD compared to CD. As the number of chewing cycles increased, the UF decreased. TOD recorded significant higher chewing efficiency and MBF than BOD. Resilient telescopic attachments are associated with increased chewing efficiency and MBF compared bar attachments when used to retain overdentures to the implants in patients with atrophied mandibles. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chewing on the trees: Constraints and adaptation in the evolution of the primate mandible.

PubMed

Meloro, Carlo; Cáceres, Nilton Carlos; Carotenuto, Francesco; Sponchiado, Jonas; Melo, Geruza Leal; Passaro, Federico; Raia, Pasquale

2015-07-01

Chewing on different food types is a demanding biological function. The classic assumption in studying the shape of feeding apparatuses is that animals are what they eat, meaning that adaptation to different food items accounts for most of their interspecific variation. Yet, a growing body of evidence points against this concept. We use the primate mandible as a model structure to investigate the complex interplay among shape, size, diet, and phylogeny. We find a weak but significant impact of diet on mandible shape variation in primates as a whole but not in anthropoids and catarrhines as tested in isolation. These clades mainly exhibit allometric shape changes, which are unrelated to diet. Diet is an important factor in the diversification of strepsirrhines and platyrrhines and a phylogenetic signal is detected in all primate clades. Peaks in morphological disparity occur during the Oligocene (between 37 and 25 Ma) supporting the notion that an adaptive radiation characterized the evolution of South American monkeys. In all primate clades, the evolution of mandible size is faster than its shape pointing to a strong effect of allometry on ecomorphological diversification in this group. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Radiological features of the skull in Klinefelter's syndrome and male hypogonadism.

PubMed

Kosowicz, J; Rzymski, K

1975-07-01

Skull radiographs were performed in 21 cases of Klinefelter's syndrome and in 30 cases of eunuchoidism. The radiographic changes of the skull in Klinefelter's syndrome are: temporal flattening, decreased width of the vault, narrowing of the mandible, decreased length of the skull, shortening of the anterior fossa cranii, decrease in the angle of the base, thinning of the vault bones at the major fontanelle, premature and excessive calcification of the coronal suture, deepening of the posterior fossa and shortening of the mandibular rami. In hypogonadotropic eunuchoidism the skull radiographs show: small mastoid processes, fine bones of the vault, small sella turcica, club-shaped clinoid processes, excessive development of sphenoidal sinuses and in the fourth and later decades of life a diminished bone density (osteoporosis).

Giant cell lesion of the jaw as a presenting feature of Noonan syndrome.

PubMed

Sinnott, Bridget P; Patel, Maya

2018-05-30

This is a case of a 20-year-old woman who presented with a left jaw mass which was resected and found to be a giant cell granuloma of the mandible. Her history and physical examination were suggestive for Noonan syndrome which was confirmed with genetic testing and the finding of a PTPN11 gene mutation which has rarely been associated with giant cell lesions of the jaw. Given her particular genetic mutation and the presence of a giant cell lesion, we present a case of Noonan-like/multiple giant cell lesion syndrome. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Functional anatomy of the temporomandibular joint (I).

PubMed

Sava, Anca; Scutariu, Mihaela Monica

2012-01-01

Jaw movement is analyzed as the action between two rigid components jointed together in a particular way, the movable mandible against the stabilized cranium. Jaw articulation distinguishes form most other synovial joints of the body by the coincidence of certain characteristic features. Its articular surfaces are not covered by hyaline cartilage as elsewhere. The two jointed components carry teeth the shape, position and occlusion of which having a unique influence on specific positions and movements within the joint. A fibrocartilaginous disc is interposed between upper and lower articular surfaces; this disc compensates for the incongruities in opposing parts and allows sliding, pivoting, and rotating movements between the bony components. These are the reasons for our review of the functional anatomy of the temporomandibular joint.

Giant cemento-ossifying fibroma of the mandible: a rare case.

PubMed

Sujatha, D; Shubha, Gurudath; Anuradha, Pai; Ragavendra, Mahadev Naik

2013-01-01

The World Health Organization classifies cemento-ossifying fibroma (COF) as a fibro-osseous neoplasm included among the nonodontogenic tumors derived from the mesenchymal blast cells of the periodontal ligament, with a potential for forming fibrous tissue, cementum and bone, or a combination of such elements. These are slow-growing lesions, and are more frequent in women, between the third and fourth decades of life. Case reports of massive expansile COFs (measuring more than 10 cm) are rarely reported in the literature. This article aims to describe a case of giant cemento-ossifying fibroma with radiographic and 3D CT features in a 34 year old female patient, who came with the complaint of progressive swelling of the face which had started 6 years earlier.

[Temporo-mandibular joint. Morpho-functional considerations].

PubMed

Scutariu, M D; Indrei, Anca

2004-01-01

The temporo-mandibular joint is distinguished from most other synovial joints of the body by two features: 1. the two jointed components carry teeth whose position and occlusion introduce a very strong influence on the movements of the temporo-mandibular joint and 2. its articular surfaces are not covered by hyaline cartilage, but by a dense, fibrous tissue. This paper describes the parts of the temporo-mandibular joint: the articular surfaces (the condylar process of the mandible and the glenoid part of the temporal bone), the fibrocartilaginous disc which is interposed between the mandibular and the temporal surface, the fibrous capsule of the temporo-mandibular joint and the ligaments of this joint. All these parts present a very strong adaptation at the important functions of the temporo-mandibular joint.

Craniofacial morphology and dental maturity in children with reduced somatic growth of different aetiology and the effect of growth hormone treatment.

PubMed

Davidopoulou, Sotiria; Chatzigianni, Athina

2017-12-01

Children with reduced somatic growth may present various endocrinal diseases, especially growth hormone deficiency (GHD), idiopathic short stature (ISS), chromosomal aberrations, or genetic disorders. In an attempt to normalize the short stature, growth hormone (GH) is administered to these children. The aim of this literature review was to collect information about the craniofacial morphology and dental maturity in these children and to present the existing knowledge on the effect of GH treatment on the above structures.This review demonstrated that regardless of the origin of the somatic growth retardation, these children show similar craniofacial features, such as short length of the cranial base and the mandible, increased lower facial height, retropositioned mandible, and obtuse gonion angle. On the other hand, dental maturation does not demonstrate a specific pattern. Except for the above findings, muscle alterations seem to be present in individuals with short stature, who present low body muscle mass and strength, while studies on their craniofacial muscles seem to be lacking. After GH administration, the exact amount and pattern of craniofacial growth is unpredictable; however, the facial convexity decreases, mandibular length increases, and posterior facial height increases, while tooth eruption remains unaffected. Thus, it is of great importance to gain more insight into the craniofacial growth of treated and untreated children with reduced somatic growth so that the influence of GH therapy on the various craniofacial structures could be ascertained and proper orthodontic treatment could be selected.

Inferring Arthropod Phylogeny: Fossils and their Interaction with Other Data Sources.

PubMed

Edgecombe, Gregory D

2017-09-01

The past five years have witnessed a renewed interest in discrete morphological characters as a source of phylogenetic data, after a decade or more of their dismissal in favor of molecules-only approaches. This has stemmed in large part from refinements in total evidence dating, which requires morphological character matrices for extinct and extant taxa as well as temporal data from fossils. The unique contribution of palaeontology is stem groups, revealing the sequence of character acquisition in long-branch terminals and otherwise unknown character combinations and/or character states in extinct phenotypes. The origin of mandibles exemplifies an integrative approach to analyzing the origin of a complex phenotypic feature using molecular, anatomical, and palaeontological data: (1) transcriptomics defends a single origin of mandibles in the clade Mandibulata; (2) Cambrian fossils inform on morphological changes in the gnathal appendages in the mandibulate stem group; (3) molecular dating, calibrated by fossils in novel modes of exceptional preservation, draws the mandibulate crown group into the early Cambrian and constrains the timing of character evolution; and (4) functional studies in extant taxa identify genes that specify mandibular identity from a maxilla and, ultimately, a trunk limb-like precursor, as predicted by the serial similarity of these appendages in Cambrian stem-group fossils. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Digital photoelastic analysis applied to implant dentistry

NASA Astrophysics Data System (ADS)

Ramesh, K.; Hariprasad, M. P.; Bhuvanewari, S.

2016-12-01

Development of improved designs of implant systems in dentistry have necessitated the study of stress fields in the implant regions of the mandible/maxilla for better understanding of the biomechanics involved. Photoelasticity has been used for various studies related to dental implants in view of whole field visualization of maximum shear stress in the form of isochromatic contours. The potential of digital photoelasticity has not been fully exploited in the field of implant dentistry. In this paper, the fringe field in the vicinity of the connected implants (All-On-Four® concept) is analyzed using recent advances in digital photoelasticity. Initially, a novel 3-D photoelastic model making procedure, to closely mimic all the anatomical features of the human mandible is proposed. By choosing appropriate orientation of the model with respect to the light path, the essential region of interest were sought to be analysed while keeping the model under live loading conditions. Need for a sophisticated software module to carefully identify the model domain has been brought out. For data extraction, five-step method is used and isochromatics are evaluated by twelve fringe photoelasticity. In addition to the isochromatic fringe field, whole field isoclinic data is also obtained for the first time in implant dentistry, which could throw important information in improving the structural stability of the implant systems. Analysis is carried out for the implant in the molar as well as the incisor region. In addition, the interaction effects of loaded molar implant on the incisor area are also studied.

The perception of children's computer-imaged facial profiles by patients, mothers and clinicians.

PubMed

Miner, Robert M; Anderson, Nina K; Evans, Carla A; Giddon, Donald B

2007-11-01

To demonstrate the usefulness of a new imaging system for comparing the morphometric bases of children's self-perception of their facial profile with the perceptions of their mothers and treating clinicians. Rather than choosing among a series of static images, a computer imaging program was developed to elicit a range of acceptable responses or tolerance for change from which a midpoint of acceptability was derived. Using the method of Giddon et al, three profile features (upper and lower lips and mandible) from standardized images of 24 patients aged 8- 15 years were distorted and presented to patients, parents, and clinicians in random order as slowly moving images (four frames per second) from retrusive and protrusive extremes. Subjects clicked the mouse when the image became acceptable and released it when it was no longer acceptable. Subjects responded similarly to a neutral facial profile. Patients and their mothers overestimated the protrusiveness of the mandible of the actual pretreatment profile. Consistent with related studies, mothers had a smaller tolerance for change in the soft tissue profile than the children or clinicians. The magnitudes of the children's self-preference and preferred change in a neutral face were also significantly correlated. Both patients and mothers preferred a more protrusive profile than that of the actual or neutral face for the patient and neutral face. Imaging software can be used with children to compare their preferences with those of parents and clinicians to facilitate treatment planning and patient satisfaction.

Tessier Number 30 Median Mandibular Cleft With Congenital Heart Anomalies in Qena, Egypt.

PubMed

Ali, Ahmed Ali Abdelrahim

2018-01-01

Median cleft deformities of the lower lip and mandible are very rare congenital anomalies. Our patient had median cleft of the lower lip, mandible, and the chin with tongue duplication, ankyloglossia, and cleft strap muscles with 2 neck contracture bands. This anomaly was associated with congenital heart disease transposition of great vessels, large ventricular septal defect, and severe pulmonary stenosis. Early repair was done at 6 months to improve feeding.

Bifid condyle of the mandible with associated polythelia and manual anomalies.

PubMed

Zohar, Y; Laurian, N

1987-12-01

Syndromes of oro-mandibular-skeletal anomalies are confusing by their ambiguous and overlapping components. It is our purpose to bring attention to a case comprising a group of anomalies: bifid mandibular condyle, asymmetric contralateral ascending ramus of the mandible, supernumerary nipples (polythelia), supernumerary-rudimentary postaxial sixth fingers and clinodactyly. The associated malformations presented do not correspond to any previous report. The case may therefore represent a new malformation syndrome.

[3-D analysis obtained in mandible movements in children 7-15 years old with different types of occlusion].

PubMed

Matveev, V M; Dzaraev, Ch R; Persin, L S

2007-01-01

60 children with different types occlusion--normal, distal, mesial and transverse between the ages 7-15 years were selected. Using unique computer software programme and 3D digitizer MicroScribe-G2 (Company Immersion, USA) on the articulator with mounted casts, persuaded measuring the scores in different movements of mandible habitual occlusion, maximum forward movement and maximum lateral movements. Scores were calculated and results interpreted.

Rotational Distraction for the Treatment of Severe Mandibular Retrognathia

PubMed Central

Mitsugi, Masaharu; Alcalde, Rafael E.; Yano, Tomoyuki; Uemura, Noriko; Okazaki, Mutsumi

2015-01-01

Backgrounds: The main problem with intraoral distraction of the mandible is the inability to achieve the three-dimensional mandibular correction as planned preoperatively. We developed a technique that allows spontaneous changes in the direction of mandibular elongation using an intraoral distractor. Methods: After mandibular osteotomy, the distractor is fixed to the distal segment of the mandible using a single bicortical screw, allowing anterior-posterior, vertical and limited lateromedial changes in the vector of distraction. Mandibular lengthening is performed while keeping the maxilla and mandible in class I occlusion with intermaxillary fixation. Results: As the distraction device is activated allowing mandibular elongation, the proximal segment, guided by the surrounding soft tissues, moves and rotates posterosuperiorly. Mandibular lengthening is continued until the condylar head reaches an adequate position in the mandibular fossa as confirmed clinically and radiographically. Conclusion Thirty-three patients with mandibular retrognathia received this treatment and good results were obtained. PMID:26301156

Rotational Distraction for the Treatment of Severe Mandibular Retrognathia.

PubMed

Ito, Osamu; Mitsugi, Masaharu; Alcalde, Rafael E; Yano, Tomoyuki; Uemura, Noriko; Okazaki, Mutsumi

2015-07-01

The main problem with intraoral distraction of the mandible is the inability to achieve the three-dimensional mandibular correction as planned preoperatively. We developed a technique that allows spontaneous changes in the direction of mandibular elongation using an intraoral distractor. After mandibular osteotomy, the distractor is fixed to the distal segment of the mandible using a single bicortical screw, allowing anterior-posterior, vertical and limited lateromedial changes in the vector of distraction. Mandibular lengthening is performed while keeping the maxilla and mandible in class I occlusion with intermaxillary fixation. As the distraction device is activated allowing mandibular elongation, the proximal segment, guided by the surrounding soft tissues, moves and rotates posterosuperiorly. Mandibular lengthening is continued until the condylar head reaches an adequate position in the mandibular fossa as confirmed clinically and radiographically. Thirty-three patients with mandibular retrognathia received this treatment and good results were obtained.

Solitary plasmacytoma of the mandible - a rare entity.

PubMed

Baad, Rajendra; Kapse, Sonam C; Rathod, Nanita; Sonawane, Kishor; Thete, Sanjay Gangadhar; Kumar, M Naveen

2013-06-01

Plasma cell dyscrasias (multiple myeloma, solitary plasmocytoma of bone and extra medullary plasmocytoma) are cha¬racterized by a monoclonal neoplastic proliferation of plasma cells of which Solitary plasmocytoma of bone (SPB) is a localized form. SPB is most frequently seen in vertebrae and secondarily in long bones. Its presence in jaws is extremely rare. The malignant plasma cells express monotypic cytoplasmic immunoglobulins and plasma cell-associated antigens, with an absence of immature B-cell antigens. Here we report a unique case of plasmacytoma in the right side of mandible, a chronology for diagnosis of the lesion is also reviewed along with clinical, radiographic, histopathological and immunohistochemical evidence. How to cite this article: Baad R, Kapse S C, Rathod N, Sonawane K, Thete S G, Naveen M K. Solitary Plasmacytoma of the Mandible - A Rare Entity. J Int Oral Health 2013; 5(3):97-101.

Coexistence of salivary gland cysticercosis with squamous cell carcinoma of the mandible.

PubMed

Mahajan, Dipti; Khurana, Nita; Setia, Namrata

2007-03-01

Cysticercosis is a parasitic infestation caused by the pork tapeworm larval stage, Cysticercus cellulosae. The majority of the cases present in ocular, cerebral, and subcutaneous locations. We report the presence of cysticercosis inside the submandibular gland in association with squamous cell carcinoma of the inferior alveolar ramus of the mandible. To the best of our knowledge, this is the first case report documenting cysticercosis inside a salivary gland. A 65-year-old male presented with complaints of an ulcerative lesion on the inferior alveolar ramus present for 2 months. Histological examination revealed a keratinizing well-differentiated squamous cell carcinoma involving the alveolar margin and mandible. The histopathological examination of the submandibular gland revealed cysticercosis. This case emphasizes the importance of adequate sampling of all the tissues obtained for associated infectious disorders, more so in immunosuppressed patients, which will help the clinician to manage the case appropriately.

Variant facial artery in the submandibular region.

PubMed

Vadgaonkar, Rajanigandha; Rai, Rajalakshmi; Prabhu, Latha V; Bv, Murlimanju; Samapriya, Neha

2012-07-01

Facial artery has been considered to be the most important vascular pedicle in facial rejuvenation procedures and submandibular gland (SMG) resection. It usually arises from the external carotid artery and passes from the carotid to digastric triangle, deep to the posterior belly of digastric muscle, and lodges in a groove at the posterior end of the SMG. It then passes between SMG and the mandible to reach the face after winding around the base of the mandible. During a routine dissection, in a 62-year-old female cadaver, in Kasturba Medical College Mangalore, an unusual pattern in the cervical course of facial artery was revealed. The right facial artery was found to pierce the whole substance of the SMG before winding around the lower border of the mandible to enter the facial region. Awareness of existence of such a variant and its comparison to the normal anatomy will be useful to oral and maxillofacial surgeons.

Skeletal anchorage for intrusion of bimaxillary molars in a patient with skeletal open bite and temporomandibular disorders

PubMed Central

Iwasa, Akihiko; Horiuchi, Shinya; Kinouchi, Nao; Izawa, Takashi; Hiasa, Masahiro; Kawai, Nobuhiko; Yasue, Akihiro; Hassan, Ali H.; Tanaka, Eiji

2017-01-01

The treatment of severe skeletal anterior open bite is extremely difficult in adults, and orthognathic surgery is generally selected for its treatment. We report the case of an 18-year-old adult patient with skeletal anterior open bite and temporomandibular disorders who was successfully treated using temporary anchorage devices. She had an open bite of −2.0 mm and an increased facial height. Miniplates were implanted in both the maxilla and mandible, and molar intrusion resulted in counterclockwise rotation of the mandible over a period of 12 months. After active treatment, her upper and lower first molars were intruded by approximately 2 mm and her overbite became +2.5 mm. Her retrognathic profile improved with counterclockwise rotation of the mandible. Orthodontic treatment aided with skeletal anchorage is beneficial for intrusion of bimaxillary molars in patients with anterior open bite. PMID:29119097

Cemento-ossifying fibroma of the mandible.

PubMed

Trijolet, J-P; Parmentier, J; Sury, F; Goga, D; Mejean, N; Laure, B

2011-01-01

Cemento-ossifying fibroma is a rare benign tumor most often discovered incidentally. A 72-year-old patient was referred for a subclinical lesion of the mandible. The orthopantomogram showed a well-circumscribed radiolucent osteolytic image, 1 cm in diameter, on the mandibular angle. On CT, the single lesion had a tissue aspect with a peripheral halo without enhancement after contrast injection. A cortical lacuna on the lingual side was noted. Surgical enucleation of the lesion was performed. The pathological examination confirmed the ossifying fibroma. Slow and progressive, cemento-ossifying fibroma is a rare benign tumor that reaches the maxilla and more frequently the mandible. The ossifying and cementifying fibromas are differentiated by their clinical, radiological, and histological findings. The authors discuss the pathogenesis and radiological signs guiding the choice of diagnostic and therapeutic methods. The treatment is surgical with an enucleation or wider resection with bone reconstruction for large fibromas. Copyright © 2010. Published by Elsevier Masson SAS.

Biomechanical implications of cortical elastic properties of the macaque mandible.

PubMed

Dechow, Paul C; Panagiotopoulou, Olga; Gharpure, Poorva

2017-10-01

Knowledge of the variation in the elastic properties of mandibular cortical bone is essential for modeling bone function. Our aim was to characterize the elastic properties of rhesus macaque mandibular cortical bone and compare these to the elastic properties from mandibles of dentate humans and baboons. Thirty cylindrical samples were harvested from each of six adult female rhesus monkey mandibles. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived from ultrasound velocity measurements. Further velocity measurements with longitudinal and transverse ultrasonic transducers along with measurements of bone density were used to compute three-dimensional cortical elastic properties using equations based on Hooke's law. Results showed regional variations in the elastic properties of macaque mandibular cortical bone that have both similarities and differences with that of humans and baboons. So far, the biological and structural basis of these differences is poorly understood. Copyright © 2017 Elsevier GmbH. All rights reserved.

Endodontic management of horizontally placed molars after gunshot injury to mandible: a case report.

PubMed

Nawal, Ruchika Roongta; Sehgal, Ritu; Ansari, Irfan; Talwar, Sangeeta; Sood, Abhinav; Verma, Mahesh

2009-11-01

A 37-year-old man reported to our department with the history of gunshot injury to the mandible 15 years before. His anterior mandible had been resected earlier and bone graft was seen. Intraoral examination of lower jaw revealed 4 remaining mandibular molars. These teeth were severely rotated such that they lay horizontal with respect to the mandibular base. Preoperative Dentascan spiral computerized tomography (CT) of the patient revealed obliteration of the mesial canals of the mandibular right first molar and pear-shaped internal resorption defect in the distal canal of the same tooth. This paper reports the challenging endodontic management of a rare case of severely angulated teeth also exhibiting traumatic sequelae in both roots of the impact tooth. It also highlights the usefulness of spiral CT scan in diagnosis of traumatic sequelae such as pulp canal obliteration and internal resorption.

Inferior alveolar nerve block: Alternative technique

PubMed Central

Thangavelu, K.; Kannan, R.; Kumar, N. Senthil

2012-01-01

Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. Aim and Objective: The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. Materials and Methods: This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. Conclusion: This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages. PMID:25885503

Inferior alveolar nerve block: Alternative technique.

PubMed

Thangavelu, K; Kannan, R; Kumar, N Senthil

2012-01-01

Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages.

Evidence of behavioral co-option from context-dependent variation in mandible use in trap-jaw ants ( Odontomachus spp.)

NASA Astrophysics Data System (ADS)

Spagna, Joseph C.; Schelkopf, Adam; Carrillo, Tiana; Suarez, Andrew V.

2009-02-01

Evolutionary co-option of existing structures for new functions is a powerful yet understudied mechanism for generating novelty. Trap-jaw ants of the predatory genus Odontomachus are capable of some of the fastest self-propelled appendage movements ever recorded; their devastating strikes are not only used to disable and capture prey, but produce enough force to launch the ants into the air. We tested four Odontomachus species in a variety of behavioral contexts to examine if their mandibles have been co-opted for an escape mechanism through ballistic propulsion. We found that nest proximity makes no difference in interactions with prey, but that prey size has a strong influence on the suite of behaviors employed by the ants. In trials involving a potential threat (another trap-jaw ant species), vertical jumps were significantly more common in ants acting as intruders than in residents (i.e. a dangerous context), while horizontal jumps occurred at the same rate in both contexts. Additionally, horizontal jump trajectories were heavily influenced by the angle at which the substrate was struck and appear to be under little control by the ant. We conclude that while horizontal jumps may be accidental side-effects of strikes against hard surfaces, vertical escape jumps are likely intentional defensive behaviors that have been co-opted from the original prey-gathering and food-processing functions of Odontomachus jaws.

Fine structure and functional comments of mouthparts in Platypus cylindrus (Col., Curculionidae: Platypodinae).

PubMed

Belhoucine, Latifa; Bouhraoua, Rachid T; Prats, Eva; Pulade-Villar, Juli

2013-02-01

Oak pinhole borer, Platypus cylindrus is seen in recent years as one of the biggest enemies directly involved in the observed decline of cork oak in Mediterranean forests with all the economic implications. As an ambrosia beetle, it has developed its effective drilling mouthpart enough to make tunnels in hardwood of the tree. The fine structural aspects of the mouthpart using the field emission scanning electron microscopy are analyzed about 23 adults collected in galleries of infested cork oak trees (Quercus suber) in a littoral forest of northwest Algeria. These adults are preserved in alcohol 70%, cleaned and coated with gold. The mouthparts of this beetle consist commonly of a labrum, a pair of mandibles, a pair of maxillae and the labium but with adapted structure to excavate galleries in the hardwood. In this role is also involved the first pair of legs. The function that present the different structures related to the construction of the tunnels is discussed. Both of maxillary and labial palpi direct the food to the mouth and hold it while the mandibles chew the food. The distal ends of these palpi are flattened and have shovel-like setae. Females have larger maxillary palpi than males and this is related to the particular biology of each sex. Copyright © 2012 Elsevier Ltd. All rights reserved.

Clinical Characterization of Canine Acanthomatous Ameloblastoma (CAA) in 263 dogs and the Influence of Postsurgical Histopathological Margin on Local Recurrence.

PubMed

Goldschmidt, Stephanie L; Bell, Cindy M; Hetzel, Scott; Soukup, Jason

2017-12-01

Canine acanthomatous ameloblastoma (CAA) has been reported to be the most common odontogenic tumor in dogs. This retrospective study evaluated 263 dogs with histopathologically confirmed CAA. Within this data set, CAA presents most commonly in the rostral mandible in adult large breed dogs, with golden retriever dogs being overrepresented. Patients with appropriate follow-up after curative intent surgery were evaluated to assess the effect of histopathological margin on local tumor recurrence. No local recurrence was noted in any patient. This study raises questions about what the recommended surgical margin should be for treatment of CAA. It also serves as a stimulus for discussion as to whether further treatment for CAA is required when inadequate surgical margins are obtained, or if medical surveillance would be an appropriate management recommendation. Prospective studies are necessary to answer these questions.

Orthognathic Surgery for the Correction of Severe Skeletal Class III Malocclusion.

PubMed

Kafle, D; Upadhayaya, C; Chaurasia, N; Agarwal, A

2016-01-01

Skeletal Malocclusions results from the abnormal position of maxilla and mandible in relation with cranial base. These types of malocclusion are commonly treated by orthodontic teeth movement known as camouflage orthodontics. However severe skeletal malocclusions cannot be treated by orthodontics alone. Such cases need surgical intervention to align the position of the jaw along with orthodontic correction. This procedure is commonly known as Orthognathic Surgery. Orthognathic Surgery dates back to early eighteenth century but became popular on mid twentieth century. Though the prevalence of skeletal malocclusion is more than 1% the treatment facility was not available in Nepal till 2012. Here we present a case of Skeletal Class III malocclusion treated at Dhulikhel Hospital, Kathmandu University Hospital. For this case, double jaw surgery was performed by le-Fort I osteotomy and Bilateral Sagital Split Osteotomy. Orthognathic surgery has been routinely performed at this centre since then.

Aggressive aneurysmal bone cyst of the maxilla confused with telangiectatic osteosarcoma.

PubMed

Lee, Hyun-Min; Cho, Kyu-Sup; Choi, Kyung-Un; Roh, Hwan-Jung

2012-06-01

Aneurysmal bone cyst (ABC) is a benign, expansile lesion typically affecting the long bones and vertebrae of patients younger than 20 years. Approximately 2% of ABCs occur in the head and neck region, most commonly affecting the mandible. Although the most common co-existing lesion associated with ABCs is the giant cell tumor, ABCs can be radiologically confused with telangiectatic osteosarcoma in cases of aggressive behavior and rapid growth. Here, we report a case of an aggressive ABC of the maxilla confused with telangiectatic osteosarcoma in a patient who underwent several operations for an osteoblastoma that was diagnosed histopathologically. This case highlights the need for a differential diagnosis both radiologically and histopathologically, because ABCs can easily be interpreted as a giant cell tumor or an osteoblastoma, and, on occasion, can be mistaken for osteogenic malignancies. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein

PubMed Central

Foster, B.L.; Ao, M.; Willoughby, C.; Soenjaya, Y.; Holm, E.; Lukashova, L.; Tran, A. B.; Wimer, H.F.; Zerfas, P.M.; Nociti, F.H.; Kantovitz, K.R.; Quan, B.D.; Sone, E.D.; Goldberg, H.A.; Somerman, M.J.

2015-01-01

Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp−/− mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp−/− mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp−/− mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp−/− mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified in endochondral ossification in the cranial base, and craniofacial morphology was unaffected in Bsp−/− mice. These analyses confirm a critical role for BSP in processes of cementogenesis and intramembranous ossification of craniofacial bone, whereas endochondral ossification in the cranial base was minimally affected and dentinogenesis was normal in Bsp−/− molar teeth. Dissimilar effects of loss of BSP on mineralization of dental and craniofacial tissues suggest local differences in the role of BSP and/or yet to be defined interactions with site-specific factors. PMID:25963390

The modular endoprosthesis for mandibular body replacement. Part 2: finite element analysis of endoprosthesis reconstruction of the mandible.

PubMed

Wong, Raymond C W; Tideman, Henk; Merkx, Matthias A W; Jansen, John; Goh, Suk Ming

2012-12-01

Problems with loosening of the modules for the modular endoprosthesis were encountered in animal studies for mandibular body replacement. We performed a finite element analysis to look at the stress distribution and areas of stress concentration in a human sized mandible. Variations were made to the stem and defect length to look at how the forces changed. The hypothesis was: (1) reconstruction with a modular endoprosthesis did not lead to areas of stress concentration beyond the material strength of cortical bone and titanium alloy; (2) changes in dimensions of the endoprosthesis did not cause a corresponding linear increase to the stresses. The endoprosthesis was modelled to create a male, female part with stems and a connection screw (Case I). The stem length was halved (Case II) and defect length doubled (Case III). Geometric data of a human sized mandible were obtained, a continuity defect created digitally at the right molar area and the models combined. Boundary conditions were set and the model loaded to get a bite force of 300 N at the incisor region. An intact mandible was used as a control. The right side of the reconstructed mandible became less rigid and flexed more. The highest stresses were within the endoprosthesis at two areas of stress concentration: (1) shear stress at the superior surface of the stems close to the junction of the stem and the module body; (2) compressive stresses at the bottom bevel of the dove-tailed connection. The stress distribution for Case I and II did not differ much except for the magnitude which was slightly higher for Case II. There was a tendency for outward bending at the module connection for Case III which potentially might cause loosening of the module connection. Displacements of the mandible were less than 1 mm throughout. The endoprosthesis with its present dimensions would be expected to perform adequately at a bite force of 300 N. An increase in defect length caused a tendency for bending at the stem and the module connection. With a decrease in stem length, there were little differences except a slight increase in magnitude. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Mandibular fracture caused by periodontal abscess: Radiological, US, CT and MRI findings.

PubMed

Mazza, D; Marini, M; Tesei, J; Primicerio, P

2006-09-01

Mandibular fracture is a rare but possible outcome of a periodontal abscess. A case of complete fracture of the mandible with abscess infiltrating the surrounding soft tissues is described. The patient reported nor trauma, nor locoregional surgery. Ultrasonography and orthopantomography revealed the fracture of the mandible and the abscess at the masseter muscle. Further preoperative diagnostic examinations included CT and MRI. CT revealed the complete fracture line more clearly; MR the extension of the abscess.

Primary intraosseous squamous cell carcinoma of the mandible arising de novo.

PubMed

Shamim, Thorakkal

2009-07-01

Primary intraosseous squamous cell carcinoma is an odontogenic tumour with aggressive behaviour usually noticed in 6th to 7th decades of life. The tumour is characterized by progressive swelling of the jaw, pain and loosening of teeth. Microscopically, the lesion is showing foci of keratinising cells separated by collagenous connective tissue stroma. A case of primary intraosseous squamous cell carcinoma of mandible arising de novo in a 40-year-old man is reported.

Les restes humains néandertaliens immatures de la couche 4A de la grotte Scladina (Andenne, Belgique)

NASA Astrophysics Data System (ADS)

Toussaint, Michel; Otte, Marcel; Bonjean, Dominique; Bocherens, Hervé; Falguères, Christophe; Yokoyama, Yuji

1998-05-01

Nine Neandertal remains, including a mandible, a maxillary fragment and various teeth, have been discovered in recent years on Level 4A of the Scladina cave. They belong to a child around 10 years old or slightly older. The mandible presents a series of plesiomorphic traits but shows only very few derived characters 'typical' of adult Neandertals. The diet of this child appears to be strongly carnivorous.

Automatic Molar Extraction from Dental Panoramic Radiographs for Forensic Personal Identification

NASA Astrophysics Data System (ADS)

Samopa, Febriliyan; Asano, Akira; Taguchi, Akira

Measurement of an individual molar provides rich information for forensic personal identification. We propose a computer-based system for extracting an individual molar from dental panoramic radiographs. A molar is obtained by extracting the region-of-interest, separating the maxilla and mandible, and extracting the boundaries between teeth. The proposed system is almost fully automatic; all that the user has to do is clicking three points on the boundary between the maxilla and the mandible.

Evaluation of the accuracy of linear measurements on multi-slice and cone beam computed tomography scans to detect the mandibular canal during bilateral sagittal split osteotomy of the mandible.

PubMed

Freire-Maia, B; Machado, V deC; Valerio, C S; Custódio, A L N; Manzi, F R; Junqueira, J L C

2017-03-01

The aim of this study was to compare the accuracy of linear measurements of the distance between the mandibular cortical bone and the mandibular canal using 64-detector multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT). It was sought to evaluate the reliability of these examinations in detecting the mandibular canal for use in bilateral sagittal split osteotomy (BSSO) planning. Eight dry human mandibles were studied. Three sites, corresponding to the lingula, the angle, and the body of the mandible, were selected. After the CT scans had been obtained, the mandibles were sectioned and the bone segments measured to obtain the actual measurements. On analysis, no statistically significant difference was found between the measurements obtained through MSCT and CBCT, or when comparing the measurements from these scans with the actual measurements. It is concluded that the images obtained by CT scan, both 64-detector multi-slice and cone beam, can be used to obtain accurate linear measurements to locate the mandibular canal for preoperative planning of BSSO. The ability to correctly locate the mandibular canal during BSSO will reduce the occurrence of neurosensory disturbances in the postoperative period. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Regeneration of a Tooth in a Tissue-Engineered Mandible After Resection of a Central Giant Cell Tumor. Demonstrating Evidence of Functional Matrix Theory and Ectodermal Origin of Teeth in a Human Model-A Case Report.

PubMed

Melville, James C; Couey, Marcus A; Tong, Matthew S; Marx, Robert E

2017-04-01

Central giant cell tumors (CGCTs) are uncommon lesions occurring in the jaw. They are benign but locally destructive osteolytic lesions. They usually occur in pediatric patients 5 to 15 years of age. Multiple noninvasive modalities of treatment (intralesional steroids, interferon, calcitonin, and denosumab) have been described for those lesions, but for those that are refractory to treatment, enucleation and curettage or resection is a curative surgery. This case report describes a pediatric patient who was diagnosed with an aggressive CGCT of the left mandible encompassing the right angle to the condyle. The lesion became refractory to noninvasive treatments and immediate resection and reconstruction was performed using principles of tissue engineering. After 5 years of close observation, the patient showed normal morphology and growth of his mandible, but surprisingly developed a left mandibular third molar (tooth 17) in the site of the mandibular resection and reconstruction. This is the first case report in the literature to show the spontaneous development of teeth in a human reconstructed mandible, contributing evidence toward the functional matrix theory of mandibular growth and ectodermal origin of teeth. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Updates in Head and Neck Reconstruction.

PubMed

Largo, Rene D; Garvey, Patrick B

2018-02-01

After reading this article, the participant should be able to: 1. Have a basic understanding of virtual planning, rapid prototype modeling, three-dimensional printing, and computer-assisted design and manufacture. 2. Understand the principles of combining virtual planning and vascular mapping. 3. Understand principles of flap choice and design in preoperative planning of free osteocutaneous flaps in mandible and midface reconstruction. 4. Discuss advantages and disadvantages of computer-assisted design and manufacture in reconstruction of advanced oncologic mandible and midface defects. Virtual planning and rapid prototype modeling are increasingly used in head and neck reconstruction with the aim of achieving superior surgical outcomes in functionally and aesthetically critical areas of the head and neck compared with conventional reconstruction. The reconstructive surgeon must be able to understand this rapidly-advancing technology, along with its advantages and disadvantages. There is no limit to the degree to which patient-specific data may be integrated into the virtual planning process. For example, vascular mapping can be incorporated into virtual planning of mandible or midface reconstruction. Representative mandible and midface cases are presented to illustrate the process of virtual planning. Although virtual planning has become helpful in head and neck reconstruction, its routine use may be limited by logistic challenges, increased acquisition costs, and limited flexibility for intraoperative modifications. Nevertheless, the authors believe that the superior functional and aesthetic results realized with virtual planning outweigh the limitations.

The use of resorbable plates in association with dental arch stabilization in the treatment of mandibular fractures in children.

PubMed

Li, Zhi; David, Ongodia; Li, Zu-Bing

2014-07-01

The purpose of this study was to investigate the effect of resorbable plate fixation in association with dental arch stabilization in the treatment of displaced mandibular fractures in children. Thirteen children (5 girls and 8 boys, age range 2 years 5 months to 12 years 2 months) with displaced mandibular fractures were included in this case series. Open reduction by intraoral approach was performed on these patients, and the fractures were fixed using resorbable plates and monocortical screws placed at the lower border of the mandible. At the same time, an arch bar or orthodontic wire splint was anchored using stainless steel wires or resin on the teeth to stabilize the whole mandibular dental arch. Postoperatively, follow-up was undertaken to evaluate the fracture healing, mandible movement, and mandible growth. Postoperatively, all patients achieved uneventful healing; premorbid occlusion restoration and wound healing were achieved, along with unimpaired function and normal growth and development of the mandible. Complications such as damage to tooth buds, infection, malunion, and nonunion were not encountered in these patients. Resorbable plates use in association with dental arch stabilization can provide good stabilization for mandibular fractures and is a promising approach for the treatment of displaced mandibular fractures in children. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

A study of the utility of measuring mandibular mobility by means of the interincisal dimension.

PubMed

Ellis, E; Fonseca, R J; Upton, L G; Scott, R F

1989-02-01

The purpose of this investigation was to determine the reliability of using the interincisal dimension as a measure of mandibular range of motion. Thirty patients who underwent mandibular advancement and 15 patients who underwent mandibular setback were included in this study. Preoperatively, a lateral cephalogram in centric relation and a second cephalogram with the mandible at maximum voluntary gape were obtained. Immediately following surgery, another centric relation cephalogram was obtained. A composite tracing of the two preoperative tracings was made to show how the mandible changed in position from the closed-mouth to the open-mouth radiographs. The proximal segment (ramus) of the postoperative cephalogram was then superimposed on the open-mouth mandibular ramus, and the distal segment of the postoperative mandible was drawn. This composite produced a tracing of what the postoperative maximal gape cephalogram would be if the same amount of condylar rotation and translation as in the preoperative tracing had occurred. The preoperative interincisal dimension was recorded on the composite tracings (factoring in any overbite or openbite) as was the would-be postoperative interincisal dimension. These measures were compared using the paired t test and Pearson's correlations to determine if there were any significant differences between them. The results showed that the interincisal dimension is a fairly reliable measure of mandibular mobility even when the length of the mandible is altered with surgery.

Experimental Validation of Plastic Mandible Models Produced by a "Low-Cost" 3-Dimensional Fused Deposition Modeling Printer.

PubMed

Maschio, Federico; Pandya, Mirali; Olszewski, Raphael

2016-03-22

The objective of this study was to investigate the accuracy of 3-dimensional (3D) plastic (ABS) models generated using a low-cost 3D fused deposition modelling printer. Two human dry mandibles were scanned with a cone beam computed tomography (CBCT) Accuitomo device. Preprocessing consisted of 3D reconstruction with Maxilim software and STL file repair with Netfabb software. Then, the data were used to print 2 plastic replicas with a low-cost 3D fused deposition modeling printer (Up plus 2®). Two independent observers performed the identification of 26 anatomic landmarks on the 4 mandibles (2 dry and 2 replicas) with a 3D measuring arm. Each observer repeated the identifications 20 times. The comparison between the dry and plastic mandibles was based on 13 distances: 8 distances less than 12 mm and 5 distances greater than 12 mm. The mean absolute difference (MAD) was 0.37 mm, and the mean dimensional error (MDE) was 3.76%. The MDE decreased to 0.93% for distances greater than 12 mm. Plastic models generated using the low-cost 3D printer UPplus2® provide dimensional accuracies comparable to other well-established rapid prototyping technologies. Validated low-cost 3D printers could represent a step toward the better accessibility of rapid prototyping technologies in the medical field.

Tongue-mandible coupling movements during saliva swallowing.

PubMed

Bourdiol, P; Mishellany-Dutour, A; Peyron, M-A; Woda, A

2014-03-01

The purpose of this study was to measure the tongue and mandible positions and displacements in relation to the maxilla in the midsagittal plane to characterize the different saliva swallowing patterns by recording their kinematics. A 2D electromagnetic articulograph using four transducer coils, three attached to the upper surface of the tongue midline plus one attached to the chin anterior part allowed continuous evaluation of tongue and chin movements in twelve young adults in good general health. During 170 s sequences recorded at a frequency of 100 Hz, subjects were at rest, silently reading a text they had chosen. The subjects were free to swallow during the sequence. Deglutition of accumulated saliva was analysed after averaging all values obtained during successive 250 ms periods. We identified three elementary swallowing patterns. Mean duration of tongue-mandible movements were 1·51 ± 0·17 s, 1·63 ± 0·14 s and 2·00 ± 0·08 s for the first, second and third patterns respectively. In the light of other studies based on intra-oral pressure recordings, our results help to understand the tongue-mandible coupling behaviours involved in managing an in-mouth saliva bolus during the three elementary swallowing patterns identified. © 2014 John Wiley & Sons Ltd.

Histomorphometric analysis following augmentation of the posterior mandible using cancellous bone-block allograft.

PubMed

Nissan, Joseph; Marilena, Vered; Gross, Ora; Mardinger, Ofer; Chaushu, Gavriel

2011-06-15

The present study was conducted to histologically and histomorphometrically evaluate the application of cancellous bone-block allografts for the augmentation of the posterior atrophic mandible. Twenty-four consecutive patients underwent augmentation with cancellous bone-block allografts in the posterior mandible. A bony deficiency of at least 3 mm horizontally and/or vertically according to CT para-axial reconstruction served as inclusion criteria. Following 6 months, 85 implants were placed and a cylindrical sample core was collected. All specimens were prepared for histological and histomorphometrical examination. Implant survival rate was 95.3%. Follow-up ranged 12-66 months (mean 43 ± 19 months). The mean newly formed bone was 44 ± 28%, that of the residual cancellous bone-block allograft 29 ± 24%, and of the marrow and connective tissue 27 ± 21%. Statistically significant histomorphometric differences regarding newly formed bone (69% vs. 31%, p = 0.05) were found between younger (< 45 years) and older (> 45 years) patients, respectively. Histomorphometric differences regarding residual cancellous bone-block allograft (17% vs. 35%) and of the marrow and connective tissue (14% vs. 34%) were not statistically significant. Cancellous bone-block allograft is biocompatible and osteoconductive, permitting new bone formation following augmentation of extremely atrophic posterior mandible with a two-stage implant placement procedure. New bone formation was age-dependent. Copyright © 2011 Wiley Periodicals, Inc.

Experimental Validation of Plastic Mandible Models Produced by a “Low-Cost” 3-Dimensional Fused Deposition Modeling Printer

PubMed Central

Maschio, Federico; Pandya, Mirali; Olszewski, Raphael

2016-01-01

Background The objective of this study was to investigate the accuracy of 3-dimensional (3D) plastic (ABS) models generated using a low-cost 3D fused deposition modelling printer. Material/Methods Two human dry mandibles were scanned with a cone beam computed tomography (CBCT) Accuitomo device. Preprocessing consisted of 3D reconstruction with Maxilim software and STL file repair with Netfabb software. Then, the data were used to print 2 plastic replicas with a low-cost 3D fused deposition modeling printer (Up plus 2®). Two independent observers performed the identification of 26 anatomic landmarks on the 4 mandibles (2 dry and 2 replicas) with a 3D measuring arm. Each observer repeated the identifications 20 times. The comparison between the dry and plastic mandibles was based on 13 distances: 8 distances less than 12 mm and 5 distances greater than 12 mm. Results The mean absolute difference (MAD) was 0.37 mm, and the mean dimensional error (MDE) was 3.76%. The MDE decreased to 0.93% for distances greater than 12 mm. Conclusions Plastic models generated using the low-cost 3D printer UPplus2® provide dimensional accuracies comparable to other well-established rapid prototyping technologies. Validated low-cost 3D printers could represent a step toward the better accessibility of rapid prototyping technologies in the medical field. PMID:27003456

Conservatism and Adaptability during Squirrel Radiation: What Is Mandible Shape Telling Us?

PubMed Central

Casanovas-Vilar, Isaac; van Dam, Jan

2013-01-01

Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing shape and size variation in the mandible of extant squirrels using landmark-based geometric morphometrics in combination with a comparative phylogenetic analysis. Dietary specialization and locomotion were found to be reliable predictors of mandible shape, with the prediction by locomotion probably reflecting the underlying diet. In addition a weak but significant allometric effect could be demonstrated. Our results found a strong phylogenetic signal in the family as a whole as well as in the main clades, which is in agreement with the general notion of squirrels being a conservative group. This fact does not preclude functional explanations for mandible shape, but rather indicates that ancient adaptations kept a prominent role, with most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous adaptations that allow them to specialize on unique dietary resources. Such adaptations mostly occurred in the Callosciurinae and probably reflect their radiation into the numerous ecological niches of the tropical and subtropical forests of Southeastern Asia. Our dietary reconstruction for the oldest known fossil squirrels (Eocene, 36 million years ago) show a specialization on nuts and seeds, implying that the development from protrogomorphous to sciuromorphous skulls was not necessarily related to a change in diet. PMID:23593456

MARS: A protein family involved in the formation of vertical skeletal elements.

PubMed

Abehsera, Shai; Peles, Shani; Tynyakov, Jenny; Bentov, Shmuel; Aflalo, Eliahu D; Li, Shihao; Li, Fuhua; Xiang, Jianhai; Sagi, Amir

2017-05-01

Vertical organizations of skeletal elements are found in various vertebrate teeth and invertebrate exoskeletons. The molecular mechanism behind the development of such structural organizations is poorly known, although it is generally held that organic matrix proteins play an essential role. While most crustacean cuticular organizations exhibit horizontal chitinous layering, a typical vertical organization is found towards the surface of the teeth in the mandibles of the crayfish Cherax quadricarinatus. Candidate genes encoding for mandible-forming structural proteins were mined in C. quadricarinatus molt-related transcriptomic libraries by using a binary patterning approach. A new protein family, termed the Mandible Alanine Rich Structural (MARS) protein family, with a modular sequence design predicted to form fibers, was found. Investigations of spatial and temporal expression of the different MARS genes suggested specific expression in the mandibular teeth-forming epithelium, particularly during the formation of the chitinous vertical organization. MARS loss-of-function RNAi experiments resulted in the collapse of the organization of the chitin fibers oriented vertically to the surface of the crayfish mandibular incisor tooth. A general search of transcriptomic libraries suggested conservation of MARS proteins across a wide array of crustaceans. Our results provide a first look into the molecular mechanism used to build the complex crustacean mandible and into the specialized vertical structural solution that has evolved in skeletal elements. Copyright © 2017 Elsevier Inc. All rights reserved.

Complications and patient-centered outcomes with an implant-supported monolithic zirconia fixed dental prosthesis: 1 year results.

PubMed

Limmer, Bryan; Sanders, Anne E; Reside, Glenn; Cooper, Lyndon F

2014-06-01

To characterize the number and type of complications that occur with a monolithic zirconia fixed dental prosthesis (MZ-FDP) supported by four endosseous implants in the edentulous mandible over time and to quantify the impact of treatment on oral health quality of life (OHQoL). Seventeen edentulous participants were enrolled. New conventional dentures were fabricated for each participant. Four Astra Tech Osseospeed TX implants (Dentsply) were then placed in the parasymphyseal mandible, and after a period of healing, a full-arch monolithic zirconia prosthesis (Zirkonzahn) was inserted. Complication data were recorded and OHQoL was evaluated using the Oral Health Impact Profile (OHIP-49), administered on four occasions: enrollment; implant surgery; and 6- and 12-month recalls. Sixty-eight implants were placed in 17 edentulous individuals aged 30 to 78 (mean 57.9 years). Implant survival was 94% from the subject perspective and 99% from the implant perspective. Prosthesis survival was 88%. Twelve complications occurred in ten participants, whereas seven participants remained complication free. Both OHIP-49 severity and extent scores decreased significantly between enrollment and 12-month recall (p < 0.001). The mean OHIP-49 severity score at baseline was 94.8 (95% confidence interval [CI]: 73.9, 115.8) and declined an average of 76.8 (95% CI: -91.3, -62.3) units per participant. The mean OHIP-49 extent score at baseline was 17.2 (95% CI: 10.8, 23.6) and declined 16.3 (95% CI: -20.2, -12.4) units per participant on average. Implant survival was high, and few complications related to the MZ-FDP were observed. The most common prosthetic complication was tooth chipping in the opposing maxillary denture, which accounted for 50% of all complication events. Substantial and clinically important improvements in OHQoL were achieved with both conventional dentures and the implant-supported MZ-FDP. The data of this short-term study indicate that the implant-supported MZ-FDP is a therapeutic option with particular advantages in the edentulous mandible that warrants further long-term study. © 2014 by the American College of Prosthodontists.

Stress Distribution Around Single Short Dental Implants: A Finite Element Study.

PubMed

Vidya Bhat, S; Premkumar, Priyanka; Kamalakanth Shenoy, K

2014-12-01

Bone height restrictions are more common in the posterior regions of the mandible, because of either bone resorption resulting from tooth loss or even anatomic limitations, such as the position of the inferior alveolar nerve. In situations where adequate bone height is not available in the posterior mandible region, smaller lengths of implants may have to be used but it has been reported that the use of long implants (length ≥10 mm) is a positive factor in osseointegration and authors have reported failures with short implants. Hence knowledge about the stress generated on the bone with different lengths of implants needs scientific evaluation. The purpose of this study was to compare and evaluate the influence of different lengths of implants on stress upon bone in mandibular posterior area. A 3 D finite element model was made of the posterior mandible using the details from a CT scan, using computer software (ANSYS 12). Four simulated implants with lengths 6 mm, 8 mm, 10 mm and 13 mm were placed in the centre of the bone. A static vertical force of 250 N and a static horizontal force of 100 N were applied. The stress generated in the cortical and cancellous bone around the implant were recorded and evaluated with the help of ANSYS. In this study, Von Mises stress on a 6 mm implant under a static vertical load of 250 N appeared to be almost in the same range of 8 and 10 mm implant which were more as compared to 13 mm implant. Von Mises stress on a 6mm implant under a static horizontal load of 100 N appeared to be less when compared to 8, 10 and 13 mm implants. From the results obtained it may be inferred that under static horizontal loading conditions, shorter implants receive lesser load and thus may tend to transfer more stresses to the surrounding bone. While under static vertical loading the shorter implants bear more loads and comparatively transmit lesser load to the surrounding bone.

The pediatric mandible: I. A primer on growth and development.

PubMed

Smartt, James M; Low, David W; Bartlett, Scott P

2005-07-01

After studying this article, the participant should be able to: 1. Describe embryonic and fetal mandibular development. 2. Summarize the aggregate changes in mandibular form from birth to puberty. 3. Describe the eruption and maturation of the deciduous and permanent mandibular dentition. In this, the first of two articles addressing the surgical management of pediatric mandibular fractures, the authors provide a detailed discussion of mandibular development and anatomy during the fetal period, infancy, and childhood. A review of the pertinent literature was performed. The changing structure of the developing mandible is discussed, with particular attention to surgically relevant anatomical structures. Throughout development, key anatomical structures with relevance to surgical therapy change markedly in position. The mandible undergoes significant change in its bony structure and the composition of its surrounding soft tissues. The mandible's bony structure becomes more robust, with an increasingly acute gonial angle and enlargement of the ramus and body. Furthermore, the mandible provides the bony structure from which tooth buds erupt as the deciduous and permanent dentition--a process that generates significant growth of the alveolar process. As a consequence, the distance between the developing dentition and the inferior mandibular border increases. While the canal of the inferior alveolar nerve undergoes significant superior displacement, the mental foramen becomes positioned more posteriorly over time. In addition, the ligamentous and muscular attachments that surround the temporomandibular joint become increasingly robust. Throughout childhood and adolescence, the blood supply of the mandibular body changes little, with the buccal periosteal plexus and inferior dental artery making significant contributions. Mandibular growth provides the basis for normal occlusal relations and the generation of increasingly large masticatory force. Although the exact mechanisms of bone remodeling during mandibular development remain unclear, the process likely receives contributions from primary growth centers and the response to local alterations in biomechanical force produced by surrounding soft-tissue structures. A working knowledge of the changing mandibular anatomy is a prerequisite for effective clinical management of traumatic injury.

Anatomic study on mental canal and incisive nerve canal in interforaminal region in Chinese population.

PubMed

Xu, Yun; Suo, Ning; Tian, Xiufen; Li, Fei; Zhong, Guangxin; Liu, Xiaoran; Bao, Yongxing; Song, Tao; Tian, Hua

2015-08-01

This study was aimed to detect the positions of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region in Chinese population to supply the reference data of the surgical safe zone in chin for clinicians. A total of 80 formalin-fixed semi-mandibles of Chinese adult cadavers were dissected, the positions and courses of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region were measured. The mental foramina were present in all cases (100 %), and most of them were located below 2nd premolar (58.75 %). Accessory mental foramina were observed in 5 %. The anterior end of mandibular canal, extending along the course of 7.37 ± 1.10 mm above the lower border of mandible to interforaminal region about 3.54 ± 0.70 mm medial to the mental foramen, most often ended below between the two premolars (73.75 %), where it continued as the incisive nerve canal (100 %) and the mental canal (96.25 %). Mental canal, with the wall formed by compact bone, being 2.60 ± 0.60 mm in diameter and 4.01 ± 1.20 mm in length, opened into mental foramen. Incisive nerve canal, with the wall formed by thin compact bone and/or partly or completely by spongy bone, being 1.76 ± 0.27 mm in diameter and 24.87 ± 2.23 mm in length, extended to the incisor region along the course of 9.53 ± 1.43 mm above the lower border of mandible, and most often ended below the lateral incisor (70.00 %). This research recommended for chin operations in Chinese population: the surgical safe zone could be set in the region about over 4 mm anterior to the mental foramen, and over 12 mm above inferior border of mandible for anterior alveolar surgery, or within 9 mm above inferior border of mandible for genioplasty.

Tongue Blade Bite Test Predicts Mandible Fractures

PubMed Central

Neiner, John; Free, Rachael; Caldito, Gloria; Moore-Medlin, Tara; Nathan, Cherie-Ann

2015-01-01

The aim of the study is to evaluate the utility of a simple tongue blade bite test in predicting mandible fractures and use this test as an alternative screening tool for further workup. This is a retrospective chart review. An institutional review board approved the retrospective review of patients evaluated by the Department of Otolaryngology at a single institution for facial trauma performed from November 1, 2011, to February 27, 2014. Patients who had a bite test documented were included in the study. CT was performed in all cases and was used as the gold standard to diagnose mandible fractures. Variables analyzed included age, sex, fracture type/location on CT, bite test positivity, and operative intervention. A total of 86 patients met the inclusion criteria and of those 12 were pediatric patients. Majority of the patients were male (80.2%) and adult (86.0%; average age: 34.3 years). Fifty-seven patients had a negative bite test and on CT scans had no mandible fracture. Twenty-three patients had a positive bite test and a CT scan confirmed fracture. The bite test revealed a sensitivity of 88.5% (95% CI: 69.8–97.6%), specificity of 95.0% (95% CI:86.1–99%), positive predictive value [PPV] of 88.5% (95% CI: 69.8–97.6%), and negative predictive value [NPV] of 95.0% (95% CI: 86.1–99.0%). Among pediatric patients, the sensitivity was 100% (95% CI: 29.9–100%), specificity was 88.9% (95% CI: 68.4–100%), PPV was 75.0% (95% CI: 19.4–99.4%), and NPV was 100% (95% CI: 63.1–100%). The tongue blade bite test is a quick inexpensive diagnostic tool for the otolaryngologist with high sensitivity and specificity for predicting mandible fractures. In the pediatric population, where avoidance of unnecessary CT scans is of highest priority, a wider range of data collection should be undertaken to better assess its utility. PMID:27162567

Evolutionary patterns and processes in the radiation of phyllostomid bats

PubMed Central

2011-01-01

Background The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size) and diet during the phyllostomid radiation. Results The different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores) or the relative size of tooth rows and mandibular processes (sanguivores and frugivores), which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya), larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory). Conclusions The radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the remaining 20 My were marked by stasis around a number of probable adaptive peaks. A considerable amount of cladogenesis and speciation in this period is likely to be the result of non-adaptive allopatric divergence or adaptations to peaks within major dietary categories. PMID:21605452

Evolutionary patterns and processes in the radiation of phyllostomid bats.

PubMed

Monteiro, Leandro R; Nogueira, Marcelo R

2011-05-23

The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size) and diet during the phyllostomid radiation. The different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores) or the relative size of tooth rows and mandibular processes (sanguivores and frugivores), which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya), larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory). The radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the remaining 20 My were marked by stasis around a number of probable adaptive peaks. A considerable amount of cladogenesis and speciation in this period is likely to be the result of non-adaptive allopatric divergence or adaptations to peaks within major dietary categories.

A retrospective study of oral cysts in Nigerian children.

PubMed

Salako, N O; Taiwo, E O

1995-01-01

A retrospective analysis of oral cysts that were seen over an 11-year period in children at a dental institution in Nigeria was carried out. In general, oral cysts accounted for only 2.6% of the total biopsied lesions during the period under review. The most common oral cysts were the mucous retention cysts, the gingival cysts of infants and the dentigerous cyst. The commonest sites were the maxilla, the mandible and the floor of the mouth respectively and there was no significant difference in sex preference. Most of the cases were seen in the age group 11-16 years while the least was in the group aged 6-10 years.

[The treatment of patients with traumatic osteomyelitis of the mandible by using porous permeable titanium nickelide implants].

PubMed

Tazin, I D; Sysoliatin, P G; Panov, L A; Giunter, V E

2000-01-01

Use of titanium nickelide based porous permeable implants for repair of postosteomyelitis mandibular defects is discussed. Five patients with mandibular defects of different location and extent were operated on. Surgical methods are described. A clinical example of using a porous permeable implant is offered. The implant designed as a mandible was used for repair of an extensive mandibular defect. Good immediate and remote results of operations indicate good prospects of using such implants.

Thin-plate spline (TPS) graphical analysis of the mandible on cephalometric radiographs.

PubMed

Chang, H P; Liu, P H; Chang, H F; Chang, C H

2002-03-01

We describe two cases of Class III malocclusion with and without orthodontic treatment. A thin-plate spline (TPS) analysis of lateral cephalometric radiographs was used to visualize transformations of the mandible. The actual sites of mandibular skeletal change are not detectable with conventional cephalometric analysis. These case analyses indicate that specific patterns of mandibular transformation are associated with Class III malocclusion with or without orthopaedic therapy, and visualization of these deformations is feasible using TPS graphical analysis.

Archaeological Investigations at Sites 45-DO-242 and 45-DO-243, Chief Joseph Dam Project, Washington.

DTIC Science & Technology

1984-01-01

from the dorsal and ventral surfaces. On the other, asymmetry was produced by Introduction of only one shoulder during flaking. Neither specimen shows...On the other, asymmetry was produced by Introduction of only one shoulder during flaking. Neither specimen shows any evidence of hafting, i.e., both...fragments, 4 humeri, 1 humerus fragment, I ulna, 1 pelvis , 1 Innomlnate fragment, 2 femurs. Zone 24: 4 mandibles, 8 mandible fragments, 1 skull, I

Namalycastis occulta n. sp. and a new record of N. borealis (Polychaeta: Nereididae: Namanereidinae) from the Northwestern Caribbean Sea.

PubMed

Conde-Vela, Víctor Manuel

2013-01-01

The nereidid polychaete genus Namalycastis Hartman, 1959 has been recorded almost exclusively in non-marine environments. This genus includes species having four pairs of tentacular cirri, and its species mainly differ by the relative size of dorsal cirri in posterior chaetigers. Namalycastis occulta n. sp. is described based upon non-mature and mature specimens collected in the intertidal from Chetumal Bay, Quintana Roo, Mexico. Its distinctive features are the lack of notopodial spinigers, eyes, and teeth in the mandibles. Namalycastis borealis Glasby was found in Tamalcab Island, Chetumal Bay and it is the first record for Mexico. Analyses of the intraspecific variability, a key to the known species in the Grand Caribbean region, and commentaries about some taxonomic topics are also included.

Central granular cell odontogenic tumor: immunohistochemistry and ultrastructure.

PubMed

Meer, Shabnum; Altini, Mario; Coleman, Hedley; Daya, Nilesh

2004-01-01

Central granular cell odontogenic tumors are rare, with only 30 cases having been reported. The tumors usually occur in the mandibular molar area and are seen as localized painless swellings in patients older than 40 years. We report an additional case that occurred in the posterior mandible of an elderly black woman. All reported cases of this tumor are benign, and cure is effected by localized surgical excision. Ultrastructurally, the cells contain numerous lysosomes and phagocytic vacuoles. Immunohistochemically, the granular cells were positive for vimentin, CD68, muramidase, carcinogenic embryonic antigen, and bcl-2. These features support a mesenchymal origin with a possible histiocytic lineage for the granular cells. Awareness of the occurrence of this neoplasm is important to promote detection and differentiation from other intraoral granular cell lesions.

Mosaic variegated aneuploidy associated with a dysmorphic syndrome and mental handicap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehta, L.; Babu, A.; Willner, J.

1994-09-01

A 41-year-old woman was evaluated for dysmorphic features and mental handicap. Prior karyotyping had revealed 7% mosaicism for trisomy 18 in skin fibroblasts with normal blood chromosomes. Clinical features consisted of short stature, mild mental retardation, sensorineural deafness and the following dysmorphic features: short, broad neck, low posterior hairline, small palpebral fissures with iris coloboma on the right, epicanthic folds, small mouth, high palate and prominent mandible, short metacarpals and digits, particularly the fifth, with bilateral simian creases. Medical problems included non-insulin dependent diabetes mellitus, hypertension, oligomenorrhea and recent onset of diabetic neuropathy and retinal exudates. Head size and brainmore » MRI were within normal limits. Peripheral blood chromosomes revealed: 46,XX (45 cells), 46,XX,t(7;16)(q21;q21) in 1 cell, 45,X (1 cell), 48,XXXX (1 cell), 47,XX,+mar (1 cell), 48,XX,+mar,+mar (1 cell). Skin fibroblasts revealed the following karyotypes: 46,XX (25 cells), 45,X (14 cells), 47,XX,+2 (10 cells) and 47,X,+2,+7 (1 cell). Previously reported cases of mosaic variegated aneuploidy include microcephaly as a prominent feature. Chromosomes involved in the abnormality are variable. Clinical presentations in such patients are not consistent and do not appear to correlate with specific chromosome defects. This patient represents an interesting example of probable mitotic instability disrupting normal developmental processes.« less

Ameloblastomas: Clinicopathological features from 70 cases diagnosed in a single Oral Pathology service in an 8-year period

PubMed Central

Filizzola, Andressa-Incerte; Bartholomeu-dos-Santos, Teresa-Cristina-Ribeiro

2014-01-01

Ameloblastomas are odontogenic tumors that can present some distinct clinicopathological profiles when comparing different populations and studies. Objectives: The aim of the present study was to analyze the clinicopathological features from a series of ameloblastomas diagnosed in a single Oral Pathology service in Brazil in an 8-year period. Study Design: The files were revised and all cases diagnosed as ameloblastomas in the period were retrieved. All hematoxylin and eosin stained histological slides were reviewed and all clinical and radiological information were obtained through a review of the laboratory forms. Data were descriptively analyzed and a comparison was performed with the different ameloblastomas subtypes. Results: Seventy ameloblastomas composed the final sample, including 57 (81%) solid/multicystic, 9 (13%) unicystic, 2 (3%) desmoplastic and 2 (3%) peripheral ameloblastomas. Mean age of the affected patients was in the forth decade of life and there was a slight male predominance. Most tumors presented as multilocular radiolucencies, were located in the posterior mandible and showed the follicular and plexiform histological patterns. There was no difference on the mean age of the patients affected by solid and unicystic ameloblastomas. Conclusions: The present results showed that the clinicopathological features of the ameloblastomas included in this Brazilian sample were similar to the features described in most other worldwide populations. Key words:Ameloblastoma, solid, unicystic, review, epidemiology, histology. PMID:25129244

Fixation Release and the Bone Bandaid: A New Bone Fixation Device Paradigm

PubMed Central

Shayesteh Moghaddam, Narges; Jahadakbar, Ahmadreza; Amerinatanzi, Amirhesam; Skoracki, Roman; Miller, Michael; Dean, David; Elahinia, Mohammad

2017-01-01

The current gold standard of care for mandibular segmental defeat reconstruction is the use of Ti-6Al-4V immobilization hardware and fibular double barrel graft. This method is often successful immediately at restoring mandible function, however the highly stiff fixation hardware causes stress shielding of the grafted bone and stress concentration in the fixation device over time which can lead to fixation device failure and revision surgery. The purpose of reconstructive surgery could be to create normal stress trajectories in the mandible following engraftment. We investigate the use of a two stage mechanism which separates the immobilization/healing and regenerative phases of mandibular segmental defect treatment. The device includes the use of a very stiff, Ti-6Al-4V, releasable mechanism which assures bone healing. Therefore it could be released once the reconstructed boney tissue and any of its ligamentous attachments have completely healed. Underneath the released Ti-6Al-4V plate would be a pre-loaded nitinol (NiTi) wire-frame apparatus that facilitates the normal stress-strain trajectory through the engrafted bone after the graft is healed in place and the Ti-6Al-4V fixation device has been released. Due to the use of NiTi wires forming a netting that connects vascularized bone and possibly bone chips, bone grafts are also more likely to be incorporate rather than to resorb. We first evaluated a healthy adult mandible during normal mastication to obtain the normal stress-strain distribution. Then, we developed the finite element (FE) model of the mandibular reconstruction (in the M1-3 region) with the proposed fixation device during the healing (locked state) and post-healing (released state) periods. To recreate normal stress trajectory in the reconstructed mandible, we applied the Response Surface Methodology (RMS) to optimize the Bone Bandaid geometry (i.e., wire diameters and location). The results demonstrate that the proposed mechanism immobilizes the grafted bone in the locked state properly since the maximum resultant gap (21.54 micron) between the graft and host mandible surfaces are in the safe region (less than 300 micron). By considering the von Mises criteria for failure, FE analysis together with experimental studies (i.e., compressive and tensile testing on the inferior and superior fixation devices, respectively) confirm that the proposed fixation devices do not fail, showing safety factor of at least 10.3. Based on the Response Surface Methodology (RSM) technique, the optimal parameter values for the wires are achieved (0.65 mm and 1 mm for the superior and inferior wires, respectively) and the required level of preload on each wire are calculated (369.8 N and 229 N for the inferior and superior wires, respectively). The FE results for stress distribution on the reconstructed mandible during the released state closely match that of a healthy mandible. PMID:28952484

The influence of sagittal position of the mandible in facial attractiveness and social perception.

PubMed

Sena, Lorena Marques Ferreira de; Damasceno E Araújo, Lislley Anne Lacerda; Farias, Arthur Costa Rodrigues; Pereira, Hallissa Simplício Gomes

2017-01-01

This study aims at comparing the perception of orthodontists, maxillofacial surgeons, visual artists and laypersons when evaluating the influence of sagittal position of the mandible - in lateral view - in facial attractiveness; at a job hiring; and in the perception of socioeconomic profile. A black male, a white male, a black female and a white female with harmonic faces served as models to obtain a facial profile photograph. Each photograph was digitally manipulated to obtain seven facial profiles: an ideal, three simulating mandibular advancement and three simulating mandibular retrusion, producing 28 photographs. These photographs were evaluated through a questionnaire by orthodontists, maxillofacial surgeons, visual artists and laypersons. The anteroposterior positioning of the mandible exerted strong influence on the level of facial attractiveness, but few significant differences between the different groups of evaluators were observed (p < 0.05). The profiles pointed as the most attractive were also pointed as more favorable to be hired to a job position and pointed also as having the best socioeconomic condition.

Obstructive sleep apnea syndrome in a pubescent boy of short stature was improved with an orthodontic mandibular advancement oral appliance: a case report.

PubMed

Ito, Shin; Otake, Hironao; Tsuiki, Satoru; Miyao, Etsuko; Noda, Akiko

2015-01-15

We report a 16-year-old pubescent pediatric patient with obstructive sleep apnea syndrome (OSAS) and short stature whose apnea hypopnea index (AHI) was significantly reduced following the use of an orthodontic oral appliance that advances the mandible ventrally. The mandible was advanced 64% of the maximal mandibular protrusive position with use of the appliance over a 3-year period. The patient's AHI without the appliance in place decreased from 101.6/h at baseline to 11/h after treatment. Moreover, the patient's height increased 14 cm during treatment, resulting in height close to the average height for his age. Cephalometric analysis revealed an improvement in his retrognathic mandible and proclination of the upper front teeth. In conclusion, an orthodontic mandibular advancement oral appliance played an important role not only in improving the patient's OSAS but also in normalizing his physical growth during puberty. © 2015 American Academy of Sleep Medicine.

Epidemiological Evaluation of Head and Neck Sarcomas in Iran (the Study of 105 Cases Over 13 Years)

PubMed Central

Alishahi, Batoul; Kargahi, Neda; Homayouni, Solmaz

2015-01-01

Background: Head and neck sarcomas are exceedingly rare and they include 4% - 10% of all sarcomas and less than 1% of all neoplasm of head and neck. Objectives: The aim of this study is to evaluate the epidemiological characteristics of head and neck sarcomas of patients in Isfahan, Iran. Patients and Methods: In this retrospective study, from the 16000 patients whose files were evaluated, the total number of 105 head and neck sarcomas were collected. They were evaluated with due attention to age, gender of the patients and the most common location of the lesion. Results: From the total number of 105 (0.6%) patients with sarcomas, 56 were men (53.33%) and 49 women (46.66%). The most common head and neck sarcomas among this population were Osteosarcoma (32 cases, 30.47%), Chondrosarcoma (14 cases, 13.33%), and Ewing sarcoma (11 cases, 10.47%).The most common soft tissue sarcoma was Rabdomiosarcoma. Mandible was the most common location for these lesions. Conclusions: In this study, the hard tissue sarcomas were more prevalent than soft tissue ones. Hence, special attention should be paid to the patients when being diagnosed. PMID:26478791

Dental and Mandibular Morphologies of Arboroharamiya (Haramiyida, Mammalia): A Comparison with Other Haramiyidans and Megaconus and Implications for Mammalian Evolution

PubMed Central

Meng, Jin; Bi, Shundong; Wang, Yuanqing; Zheng, Xiaoting; Wang, Xiaoli

2014-01-01

Background Two recent studies published in the same issue of Nature reached conflicting conclusions regarding the phylogeny of early mammals: One places the clade containing haramiyidans and multituberculates within the Mammalia and the other separates haramiyidans from multituberculates and places the former outside of the Mammalia. These two contrasting results require that the minimally oldest divergence time of the Mammalia was within the Late Triassic or the Middle Jurassic, respectively. Morphological descriptions of the species named in the two papers were brief, and no comparisons between the newly named species were possible. Principal Findings Here we present a detailed description of the dentary bone, teeth, occlusal and wear patterns of the haramiyidan Arboroharamiya and compare it with other haramiyidans and Megaconus. Using this new information, we suggest that tooth identifications and orientations of several previously described haramiyidan species are incorrect, and that previous interpretations of haramiyidan occlusal pattern are problematic. We propose that the published upper tooth orientation of Megaconus was problematic and question the number of upper molars, the length of dentition and mandible, and presence of the mandibular middle ear in Megaconus. Conclusions The additional morphological descriptions and comparisons presented here further support the view that Arboroharamiya, as a derived haramiyidan, shows similarity to multituberculates in tooth and mandible morphologies. Our comparison also suggests that Megaconus lacks many diagnostic features for the family Eleutherodontidae and that its close affinity with multituberculates cannot be ruled out. The detailed morphological data demonstrate that haramiyidans are more similar to multituberculates than to any other mammaliaforms. PMID:25494181

Spatial distribution of dental fluorosis in roe deer (Capreolus capreolus) from North Bohemia (Czech Republic) and its relationships with environmental factors.

PubMed

Zemek, Frantisek; Herman, Michal; Kierdorf, Horst; Kierdorf, Uwe; Sedlácek, Frantisek

2006-11-01

We assessed the spatial variation of fluoride load on the local ecosystem in the Czech part of the Ore Mountains region and its southern foothills - a heavily polluted part of Europe's "Black Triangle" region. Dental fluorosis in roe deer (Capreolus capreolus) served as a biomarker of fluoride exposure and thus as an indicator of environmental pollution by fluoride. The mean dental lesion index of fluorosis (DLI) calculated from the analyzed mandibles of wild roe deer (>or=2 years of age) was assigned to the hunting ground from which the specimens originated and classified into one of the eight fluorosis categories. Environmental factors potentially related to dental fluorosis (atmospheric deposition of sulfur, concentration of fluoride in and pH of surface waters, geomorphologic features, bedrock and soil type, and vegetation cover), which were represented in the study by GIS layers, were examined to explain the distribution pattern and severity of fluorosis in the roe deer. The study revealed that 75.5% of 616 analyzed mandibles showed dental fluorosis to different extent, with individual DLIs ranging from 0 to 21. The spatial pattern of marked fluorosis on the Czech side continues that found in a previous study on the German side of the Ore Mountains. Together they create a landscape island around several thermal power plants in the region. General Linear Model (GLM) analyses revealed significant relationships between degree of forest damage, soil type, and atmospheric sulfur deposition from air pollution and dental fluorosis, expressed as mean DLI in the roe deer.

Functional and morphological correlates of mandibular symphyseal form in a living human sample.

PubMed

Holton, Nathan E; Franciscus, Robert G; Ravosa, Matthew J; Southard, Thomas E

2014-03-01

Variation in recent human mandibular form is often thought to reflect differences in masticatory behavior associated with variation in food preparation and subsistence strategies. Nevertheless, while mandibular variation in some human comparisons appear to reflect differences in functional loading, other comparisons indicate that this relationship is not universal. This suggests that morphological variation in the mandible is influenced by other factors that may obscure the effects of loading on mandibular form. It is likely that highly strained mandibular regions, including the corpus, are influenced by well-established patterns of lower facial skeletal integration. As such, it is unclear to what degree mandibular form reflects localized stresses incurred during mastication vs. a larger set of correlated features that may influence bone distribution patterns. In this study, we examine the relationship between mandibular symphyseal bone distribution (i.e., second moments of area, cortical bone area) and masticatory force production (i.e., in vivo maximal bite force magnitude and estimated symphyseal bending forces) along with lower facial shape variation in a sample of n = 20 living human male subjects. Our results indicate that while some aspects of symphyseal form (e.g., wishboning resistance) are significantly correlated with estimates of symphyseal bending force magnitude, others (i.e., vertical bending resistance) are more closely tied to variation in lower facial shape. This suggests that while the symphysis reflects variation in some variables related to functional loading, the complex and multifactorial influences on symphyseal form underscores the importance of exercising caution when inferring function from the mandible especially in narrow taxonomic comparisons. Copyright © 2013 Wiley Periodicals, Inc.

Thin-plate spline analysis of the cranial base in African, Asian and European populations and its relationship with different malocclusions.

PubMed

Rosas, Antonio; Bastir, Markus; Alarcón, Jose Antonio; Kuroe, Kazuto

2008-09-01

To test the hypothesis that midline basicranial orientation and posterior cranial base length are discriminating factors between adults of different populations and its potential maxillo/mandibular disharmonies. Twenty-nine 2D landmarks of the midline cranial base, the face and the mandible of dry skull X-rays from three major populations (45 Asians, 34 Africans, 64 Europeans) were digitized and analysed by geometric morphometrics. We used, first, MANOVA to test for mean shape differences between populations; then, principal components analysis (PCA) to assess the overall variation in the sample and finally, canonical variate analysis (CVA) with jack-knife validations (N=1000) to analyse the anatomical features that best distinguished among populations. Significant mean shapes differences were shown between populations (P<0.001). CVA revealed two significant axes of discrimination (P<0.001). Jack-knife validation correctly identified 92% of 15,000 unknowns. In Africans the whole cranial base is rotated into a forward-downward position, while in Asians it is rotated in the opposite way. The Europeans occupied an intermediate position. African and Asian samples showed a maxillo/mandibular prognathism. African prognathism was produced by an anterior positioned maxilla, Asian prognathism by retruded anterior cranial base and increase of the posterior cranial base length. Europeans showed a trend towards retracted mandibles with relatively shorter posterior cranial bases. The results supported the hypothesis that basicranial orientation and posterior cranial base length are valid factors to distinguish between geographic groups. The whole craniofacial configuration underlying a particular maxillo-facial disharmony must be considered in diagnosis, growth predictions and resulting treatment planning.

Cone-beam computed tomography evaluation of dentoskeletal changes after asymmetric rapid maxillary expansion.

PubMed

Baka, Zeliha Muge; Akin, Mehmet; Ucar, Faruk Izzet; Ileri, Zehra

2015-01-01

The aims of this study were to quantitatively evaluate the changes in arch widths and buccolingual inclinations of the posterior teeth after asymmetric rapid maxillary expansion (ARME) and to compare the measurements between the crossbite and the noncrossbite sides with cone-beam computed tomography (CBCT). From our clinic archives, we selected the CBCT records of 30 patients with unilateral skeletal crossbite (13 boys, 14.2 ± 1.3 years old; 17 girls, 13.8 ± 1.3 years old) who underwent ARME treatment. A modified acrylic bonded rapid maxillary expansion appliance including an occlusal locking mechanism was used in all patients. CBCT records had been taken before ARME treatment and after a 3-month retention period. Fourteen angular and 80 linear measurements were taken for the maxilla and the mandible. Frontally clipped CBCT images were used for the evaluation. Paired sample and independent sample t tests were used for statistical comparisons. Comparisons of the before-treatment and after-retention measurements showed that the arch widths and buccolingual inclinations of the posterior teeth increased significantly on the crossbite side of the maxilla and on the noncrossbite side of the mandible (P <0.05). Comparison of the 2 sides showed statistically significant differences in both the maxilla and the mandible (P <0.05). After ARME treatment, the crossbite side of the maxilla and the noncrossbite side of the mandible were more affected than were the opposite sides. Copyright © 2015. Published by Elsevier Inc.

Expression of caveolin-1 in the early phase of beta-TCP implanted in dog mandible.

PubMed

Chou, Cherng-Tzeh; Bhawal, Ujjal K; Watanabe, Nobuyuki; Kuboyama, Noboru; Chang, Wei-Jen; Lee, Sheng-Yang; Abiko, Yoshimitsu

2013-07-01

Caveolin is an essential and signature protein of caveolae. Caveolin-1 participates in signal transduction processes by acting as a scaffolding protein that concentrates, organizes and functional regulates signalling molecules within caveolar membranes. Beta-tricalcium phosphate (β-TCP) has been widely used for scaffold in tissue engineering due to its high biodegradability, osteoconductivity, easy manipulation, and lack of histotoxicity. To better understand the role of caveolin-1 in bone homeostasis and response to β-TCP scaffold, β-TCP was implanted into the dog mandible defects in beagle dogs, and gene expression profiles were examined focused on the molecular components involved in caveolin-1 regulation. Here we showed the quantitative imageology analysis characterized using in vivo micro-computed tomography (CT) images at 4 and 7 days after β-TCP implanted in dog mandibles. The bone reformation by using the β-TCP scaffolds began within 4 days of surgery, and was healing well at 7 days after surgery. Higher mRNA level of caveolin-1 was observed in β-TCP-implanted Beagle dog mandibles compared with controls at day 4 and day 7 post-surgery. The enhancement of caveolin-1 by β-TCP was further confirmed by immunohistochemistry and immunofluorescence analysis. We further revealed increased Smad7 and Phospho Stat3 expression in β-TCP-implanted specimens. Taken together, these results suggest that the enhancement of caveolin-1 play an important role in accelerating bone formation by β-TCP. Copyright © 2013 Wiley Periodicals, Inc.

The pediatric mandible: II. Management of traumatic injury or fracture.

PubMed

Smartt, James M; Low, David W; Bartlett, Scott P

2005-08-01

After studying this article, the participant should be able to: 1. Describe the changing epidemiology of mandibular fractures in children and adolescents. 2. Discuss the appropriate use of internal fixation in the treatment of pediatric mandibular fractures. 3. Describe the difficulties posed by the deciduous dentition in the use of interdental wiring. 4. Understand reasons why techniques specific to adult fractures may not be applicable to the growing mandible. 5. Understand the etiology and epidemiology of pediatric mandibular fractures. 6. Understand the reasons for conservative (closed) versus aggressive (open) treatment of mandibular injury. Fractures of the pediatric mandible are complicated by the anatomic complexity of the developing mandible, particularly by the presence of tooth buds and the eruption of deciduous and permanent teeth. Traditional methods of fracture reduction and fixation employed in adults have little applicability in the pediatric population. The authors describe the surgical techniques that have been used at their institution and those that can be used safely in the pediatric setting. In most cases, "conservative" management is the preferred option, especially in the treatment of condylar fractures. In cases requiring surgical intervention, interdental wiring, drop wires in combination with circummandibular wires, and acrylic splints are suited well to specific phases of dental maturation. Open reduction and internal fixation using monocortical screws and microplates or resorbable plates and screws are acceptable techniques in the pediatric patient, but they require special safeguards. Algorithms are presented to simplify management of these complicated injuries.

[Influence of trabecular microstructure modeling on finite element analysis of dental implant].

PubMed

Shen, M J; Wang, G G; Zhu, X H; Ding, X

2016-09-01

To analyze the influence of trabecular microstructure modeling on the biomechanical distribution of implant-bone interface with a three-dimensional finite element mandible model of trabecular structure. Dental implants were embeded in the mandibles of a beagle dog. After three months of the implant installation, the mandibles with dental implants were harvested and scaned by micro-CT and cone-beam CT. Two three-dimensional finite element mandible models, trabecular microstructure(precise model) and macrostructure(simplified model), were built. The values of stress and strain of implant-bone interface were calculated using the software of Ansys 14.0. Compared with the simplified model, the precise models' average values of the implant bone interface stress increased obviously and its maximum values did not change greatly. The maximum values of quivalent stress of the precise models were 80% and 110% of the simplified model and the average values were 170% and 290% of simplified model. The maximum and average values of equivalent strain of precise models were obviously decreased, and the maximum values of the equivalent effect strain were 17% and 26% of simplified model and the average ones were 21% and 16% of simplified model respectively. Stress and strain concentrations at implant-bone interface were obvious in the simplified model. However, the distributions of stress and strain were uniform in the precise model. The precise model has significant effect on the distribution of stress and strain at implant-bone interface.

Mechanisms regulating nutrition-dependent developmental plasticity through organ-specific effects in insects

PubMed Central

Koyama, Takashi; Mendes, Cláudia C.; Mirth, Christen K.

2013-01-01

Nutrition, via the insulin/insulin-like growth factor (IIS)/Target of Rapamycin (TOR) signaling pathway, can provide a strong molding force for determining animal size and shape. For instance, nutrition induces a disproportionate increase in the size of male horns in dung and rhinoceros beetles, or mandibles in staghorn or horned flour beetles, relative to body size. In these species, well-fed male larvae produce adults with greatly enlarged horns or mandibles, whereas males that are starved or poorly fed as larvae bear much more modest appendages. Changes in IIS/TOR signaling plays a key role in appendage development by regulating growth in the horn and mandible primordia. In contrast, changes in the IIS/TOR pathway produce minimal effects on the size of other adult structures, such as the male genitalia in fruit flies and dung beetles. The horn, mandible and genitalia illustrate that although all tissues are exposed to the same hormonal environment within the larval body, the extent to which insulin can induce growth is organ specific. In addition, the IIS/TOR pathway affects body size and shape by controlling production of metamorphic hormones important for regulating developmental timing, like the steroid molting hormone ecdysone and sesquiterpenoid hormone juvenile hormone. In this review, we discuss recent results from Drosophila and other insects that highlight mechanisms allowing tissues to differ in their sensitivity to IIS/TOR and the potential consequences of these differences on body size and shape. PMID:24133450

Age-related new bone formation following the use of cancellous bone-block allografts for reconstruction of atrophic alveolar ridges.

PubMed

Nissan, Joseph; Kolerman, Roni; Chaushu, Liat; Vered, Marilena; Naishlos, Sarit; Chaushu, Gavriel

2018-02-01

An age-related decrease in the number of osteogenic progenitor cells may compromise bone augmentation. Histomorphometrical assessment of age-related new bone formation, following atrophic alveolar ridge reconstruction, using cancellous bone-block allografts. Ninety-three consecutive patients (58 females and 35 males) were referred for implant-supported restoration of 122 severe atrophic alveolar ridges. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58), posterior maxilla (n= 32), and posterior mandible (n = 32). A bony deficiency of at least 3 mm horizontally and up to 3 mm vertically according to computerized tomography (CT) in the posterior mandible and anterior maxilla, served as inclusion criteria. In the posterior maxilla, a residual alveolar ridge up to 4 mm vertically according to CT served as inclusion criteria. Augmentation was performed by the use of cancellous bone-block allografts. Bone biopsies (9-month posterior maxilla, 4 months anterior maxilla and posterior mandible) of young (≤40 years) versus older (>40 years) patients were histomorphometrically evaluated. In the posterior maxilla, no statistically significant histomorphometric differences were noted. While at the anterior maxilla and posterior mandible, statistically significant more newly formed bone was found in young versus older individuals, respectively (38.6% vs 19.8%, P = 0.04 and 69% vs 31%, P = .05). New bone formation following residual alveolar ridge bone grafting is age-related. Longer bone consolidation and healing time may be recommended for older individuals. © 2017 Wiley Periodicals, Inc.

Osteoporosis prediction from the mandible using cone-beam computed tomography

PubMed Central

Al Haffar, Iyad; Khattab, Razan

2014-01-01

Purpose This study aimed to evaluate the use of dental cone-beam computed tomography (CBCT) in the diagnosis of osteoporosis among menopausal and postmenopausal women by using only a CBCT viewer program. Materials and Methods Thirty-eight menopausal and postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) examination for hip and lumbar vertebrae were scanned using CBCT (field of view: 13 cm×15 cm; voxel size: 0.25 mm). Slices from the body of the mandible as well as the ramus were selected and some CBCT-derived variables, such as radiographic density (RD) as gray values, were calculated as gray values. Pearson's correlation, one-way analysis of variance (ANOVA), and accuracy (sensitivity and specificity) evaluation based on linear and logistic regression were performed to choose the variable that best correlated with the lumbar and femoral neck T-scores. Results RD of the whole bone area of the mandible was the variable that best correlated with and predicted both the femoral neck and the lumbar vertebrae T-scores; further, Pearson's correlation coefficients were 0.5/0.6 (p value=0.037/0.009). The sensitivity, specificity, and accuracy based on the logistic regression were 50%, 88.9%, and 78.4%, respectively, for the femoral neck, and 46.2%, 91.3%, and 75%, respectively, for the lumbar vertebrae. Conclusion Lumbar vertebrae and femoral neck osteoporosis can be predicted with high accuracy from the RD value of the body of the mandible by using a CBCT viewer program. PMID:25473633

Mandibular effects of maxillary distraction osteogenesis in cleft lip and palate.

PubMed

Doucet, J-C; Herlin, C; Bigorre, M; Bäumler, C; Subsol, G; Captier, G

2014-06-01

Maxillary distraction osteogenesis (DO) is a reliable treatment for severe maxillary deficiency in cleft lip and palate (CLP). The objective was to analyze its long-term effects on the mandible. A retrospective study of 24 CLP treated with maxillary DO using the Polley and Figueroa technique was done; patients were followed for more than 4 years. Preoperative (T0), 6-12 months postoperative (T1), and ≥ 4 years postoperative (T2) cephalometric radiographs were evaluated. A classical cephalometric analysis was used to assess treatment stability, and a Procrustes superimposition method was used to assess local changes in the shape of the mandible. The mean age of patients at T0 was 15.4 ± 4.1 years. SNA increased at T1 and T2 (P < 0.001), with no significant relapse between T1 and T2, indicating stability at 1 year after treatment (T0 = 72.4 ± 5.3°; T1 = 81.3 ± 6.2°; T2 = 79.9 ± 6.1°). SNB, facial angle, gonial angle, and symphyseal angle remained stable. Long-term analysis of the mandible demonstrated a minimal counter-clockwise rotation of the body (mandibular plane = -0.2 ± 3.2°) and ramus (-0.6 ± 4.3°). Maxillary DO in CLP had no significant effect on the shape or rotation of the mandible. The maxillary advancement remained stable after 1 year. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Scaling of chew cycle duration in primates.

PubMed

Ross, Callum F; Reed, David A; Washington, Rhyan L; Eckhardt, Alison; Anapol, Fred; Shahnoor, Nazima

2009-01-01

The biomechanical determinants of the scaling of chew cycle duration are important components of models of primate feeding systems at all levels, from the neuromechanical to the ecological. Chew cycle durations were estimated in 35 species of primates and analyzed in conjunction with data on morphological variables of the feeding system estimating moment of inertia of the mandible and force production capacity of the chewing muscles. Data on scaling of primate chew cycle duration were compared with the predictions of simple pendulum and forced mass-spring system models of the feeding system. The gravity-driven pendulum model best predicts the observed cycle duration scaling but is rejected as biomechanically unrealistic. The forced mass-spring model predicts larger increases in chew cycle duration with size than observed, but provides reasonable predictions of cycle duration scaling. We hypothesize that intrinsic properties of the muscles predict spring-like behavior of the jaw elevator muscles during opening and fast close phases of the jaw cycle and that modulation of stiffness by the central nervous system leads to spring-like properties during the slow close/power stroke phase. Strepsirrhines show no predictable relationship between chew cycle duration and jaw length. Anthropoids have longer chew cycle durations than nonprimate mammals with similar mandible lengths, possibly due to their enlarged symphyses, which increase the moment of inertia of the mandible. Deviations from general scaling trends suggest that both scaling of the jaw muscles and the inertial properties of the mandible are important in determining the scaling of chew cycle duration in primates.

Cystic Shape Cemento-Ossifying Fibroma of Ethmoid Sinus

PubMed Central

Shejbal, Dražen; Vonsović, Gabrijela; Baudoin, Tomislav; Vagic, Davor

2015-01-01

Cemento-ossifying fibromas are a group of rarely occurring benign tumours, developing from the periodontal membrane and varying considerably in appearance and in the progress of the disease. Their common feature is higher or lower production of cemental tissue. In most cases the tumours are small because their cementoma mature quickly and become inactive, which causes the tumour to stop growing. They develop most frequently in the mandible and also in the maxilla. Other sites, such as paranasal cavities, soft tissues and bones of the head, are extremely rare. The case of a cemento-fibrosing tumour with psammoma infiltrations, developing from the ethmoid sinus in a nine-year-old girl is reported. Due to frontal headaches and sight defects as well as impaired vision on the right side, NMR was done, which showed a mucocele of the front and rear ethmoid with destruction of the orbital wall and a breakthrough into the orbit. The right maxillary sinus showed a visible retention and a thickened mucous membrane. A rhinoscopy revealed a ball-shaped spherical mass in the medial nasal meatus, which was defined as concha bullosa. An endoscopic examination showed that the tumour protruded in front of the medium nasal concha into the right nasal cavity, softened the ethmoid roof, penetrated toward the base of the skull, adhered and pushed the orbit. It was removed by FESS technique, and PHD revealed subsequently that it was not a mucocele but a cemento-ossifying fibroma. PMID:27688399

Cystic Shape Cemento-Ossifying Fibroma of Ethmoid Sinus.

PubMed

Shejbal, Dražen; Vonsović, Gabrijela; Baudoin, Tomislav; Vagic, Davor

2015-06-01

Cemento-ossifying fibromas are a group of rarely occurring benign tumours, developing from the periodontal membrane and varying considerably in appearance and in the progress of the disease. Their common feature is higher or lower production of cemental tissue. In most cases the tumours are small because their cementoma mature quickly and become inactive, which causes the tumour to stop growing. They develop most frequently in the mandible and also in the maxilla. Other sites, such as paranasal cavities, soft tissues and bones of the head, are extremely rare. The case of a cemento-fibrosing tumour with psammoma infiltrations, developing from the ethmoid sinus in a nine-year-old girl is reported. Due to frontal headaches and sight defects as well as impaired vision on the right side, NMR was done, which showed a mucocele of the front and rear ethmoid with destruction of the orbital wall and a breakthrough into the orbit. The right maxillary sinus showed a visible retention and a thickened mucous membrane. A rhinoscopy revealed a ball-shaped spherical mass in the medial nasal meatus, which was defined as concha bullosa. An endoscopic examination showed that the tumour protruded in front of the medium nasal concha into the right nasal cavity, softened the ethmoid roof, penetrated toward the base of the skull, adhered and pushed the orbit. It was removed by FESS technique, and PHD revealed subsequently that it was not a mucocele but a cemento-ossifying fibroma.

HEAR MAPS a classification for congenital microtia/atresia based on the evaluation of 742 patients.

PubMed

Roberson, Joseph B; Goldsztein, Hernan; Balaker, Ashley; Schendel, Stephen A; Reinisch, John F

2013-09-01

Describe anatomical and radiological findings in 742 patients evaluated for congenital aural atresia and microtia by a multidisciplinary team. Develop a new classification method to enhance multidisciplinary communication regarding patients with congenital aural atresia and microtia. Retrospective chart review with descriptive analysis of findings arising from the evaluation of patients with congenital atresia and microtia between January 2008 and January 2012 at a multidisciplinary tertiary referral center. We developed a classification method based on the acronym HEAR MAPS (Hearing, Ear [microtia], Atresia grade, Remnant earlobe, Mandible development, Asymmetry of soft tissue, Paralysis of the facial nerve and Syndromes). We used this method to evaluate 742 consecutive congenital atresia and microtia patients between 2008 and January of 2012. Grade 3 microtia was the most common external ear malformation (76%). Pre-operative Jahrsdoerfer scale was 9 (19%), 8 (39%), 7 (19%), and 6 or less (22%). Twenty three percent of patients had varying degrees of hypoplasia of the mandible. Less than 10% of patients had an identified associated syndrome. Patients with congenital aural atresia and microtia often require the intervention of audiology, otology, plastic surgery, craniofacial surgery and speech and language professionals to achieve optimal functional and esthetic reconstruction. Good communication between these disciplines is essential for coordination of care. We describe our use of a new classification method that efficiently describes the physical and radiologic findings in microtia/atresia patients to improve communication amongst care providers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Developmental odontogenic cysts of jaws: a clinical study of 245 cases.

PubMed

Yazdani, Javad; Kahnamouii, Shiva Solahaye

2009-01-01

The aim of this study was to investigate the relative frequency of developmental odontogenic cysts in an Iranian population. In this study 245 cysts from both jaws, treated in the Faculty of Dentistry at Tabriz University of Medical Sciences during a 10-year period from 1998 to 2008, were analyzed in order to evaluate the incidence of such cysts. We had permission from all the patients. Case histories of 65% of male and 35% of female patients were analyzed. The age of the patients varied from 14 to 64 years, with an average of 33.21 ± 10.89. In this 10-year study of odontogenic cysts, 97 cases were developmental odontogenic cysts with the following inci-dence: dentigerous cyst, 44%; odontogenic keratocyst, 36%; primordial cyst, 9%; Gorlin cyst, 2%; lateral periodontal cyst, 3%; eruption cyst, 3%; and gingival cyst, 3% (adults 2%, infants 1%). A total of 60% of the cysts were found in the mandible and 40% in the maxilla. Regarding the mandible, the molar region was involved in 47% of the cases, premolar region in 33% and anterior region in 20% (total = 100%). Regarding the maxilla, the canine-to-canine region was involved in 52% of the cases, premolar region in 20% and molar region in 28% (total = 100%). An important finding in this study was the fact that 39% of the jaw cysts were developmental odontogenic cysts and the most common developmental odontogenic cysts were dentigerous cyst and OKC (odontogenic keratocyst).

Incidence and pattern of mandibular fractures in Rohilkhand region, Uttar Pradesh state, India: A retrospective study

PubMed Central

Giri, Kolli Yada; Singh, Aishwarya Pratap; Dandriyal, Ramakant; Indra, Niranjanaprasad; Rastogi, Sanjay; Mall, Sunil Kumar; Chowdhury, Shouvik; Singh, Himanshu Pratap

2015-01-01

Aims To understand and evaluate the significance of various aetiological factors in determining the incidence and dictating the patterns of mandibular fractures in Rohilkhand region. Methods The patient records and radiographs for 144 patients treated for mandibular fractures were reviewed between the time periods from January 2012 to December 2013. Data on age, gender, aetiology, use of intoxicants, head injury, associated injuries, days of the week, anatomic site and multiple fractures within the mandible were recorded and assessed. Results Maximum incidence of fractures was observed among the individuals in 3rd decade (35.4%) followed by 2nd and 4th decades, which exhibited 32 and 30 cases (22.2% and 20.8%), respectively. Male to female ratio was biased (4:1) portraying a male predominance. Road traffic accidents (RTAs) were observed to be the predominant aetiological factor responsible accounting for 79.2% of the total injuries followed by assaults (11.8%) and falls (9%). Parasymphysis exhibited the highest incidence (32.63%) amongst the anatomic sites, followed by body (18.75%), angle (16.66%), condyle (15.27%), symphysis (12.50%), ramus (2.77%) and coronoid (1.38%). Conclusion The study reveals that majority of affected patients were in the 2nd and 3rd decades. A definitive relationship existed between RTA and the incidence of mandibular fractures. The frequency further increased with consumption of social intoxicants. The most commonly fractured site was parasymphysis either isolated or associated with other fractures in the mandible. PMID:26587379

A worldwide comparison of the management of T1 and T2 anterior floor of the mouth and tongue squamous cell carcinoma - Extent of surgical resection and reconstructive measures.

PubMed

Kansy, Katinka; Mueller, Andreas Albert; Mücke, Thomas; Koersgen, Friederike; Wolff, Klaus Dietrich; Zeilhofer, Hans-Florian; Hölzle, Frank; Pradel, Winnie; Schneider, Matthias; Kolk, Andreas; Smeets, Ralf; Acero, Julio; Haers, Piet; Ghali, G E; Hoffmann, Jürgen

2017-12-01

Microvascular surgery following tumor resection has become an important field of oral maxillofacial surgery (OMFS). Following the results on general aspects of current reconstructive practice in German-speaking countries, Europe and worldwide, this paper presents specific concepts for the management of resection and reconstruction of T1/T2 squamous cell carcinoma (SCC) of the anterior floor of the mouth and tongue. The DOESAK questionnaire was distributed in three different phases to a growing number of maxillofacial units worldwide. Within this survey, clinical patient settings were presented to participants and center-specific treatment strategies were evaluated. A total of 188 OMFS units from 36 different countries documented their treatment strategies for T1/T2 anterior floor of the mouth squamous cell carcinoma and tongue carcinoma. For floor of mouth carcinoma close to the mandible, a wide variety of concepts are presented: subperiosteal removal of the tumor versus continuity resection of the mandible and reconstruction ranging from locoregional closure to microvascular bony reconstruction. For T2 tongue carcinoma, concepts are more uniform. These results demonstrate the lack of evidence and the controversy of different guidelines for the extent of safety margins and underline the crucial need of global prospective randomized trials on this topic to finally obtain evidence for a common guideline based on a strong community of OMFS units. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

Global Body Posture Evaluation in Patients with Temporomandibular Joint Disorder

PubMed Central

Saito, Eliza Tiemi; Akashi, Paula Marie Hanai; de Camargo Neves Sacco, Isabel

2009-01-01

AIM: To identify the relationship between anterior disc displacement and global posture (plantar arches, lower limbs, shoulder and pelvic girdle, vertebral spine, head and mandibles). Common signs and symptoms of anterior disc displacement were also identified. INTRODUCTION: Global posture deviations cause body adaptation and realignment, which may interfere with the organization and function of the temporomandibular joint. METHODS : Global posture evaluation was performed in a group of 10 female patients (20 to 30 years of age) with temporomandibular joint disc displacement and in a control group of 16 healthy female volunteers matched for age, weight and height. Anterior disc displacement signs, symptoms and the presence of parafunctional habits were also identified through interview. RESULTS: Patients with disc displacement showed a higher incidence of pain in the temporomandibular joint area, but there were no differences in parafunctional habits between the groups. In the disc displacement group, postural deviations were found in the pelvis (posterior rotation), lumbar spine (hyperlordosis), thoracic spine (rectification), head (deviation to the right) and mandibles (deviation to the left with open mouth). There were no differences in the longitudinal plantar arches between the groups. CONCLUSION: Our results suggest a close relationship between body posture and temporomandibular disorder, though it is not possible to determine whether postural deviations are the cause or the result of the disorder. Hence, postural evaluation could be an important component in the overall approach to providing accurate prevention and treatment in the management of patients with temporomandibular disorder. PMID:19142549

Assessment of Temperature Rise and Time of Alveolar Ridge Splitting by Means of Er:YAG Laser, Piezosurgery, and Surgical Saw: An Ex Vivo Study

PubMed Central

Flieger, Rafał; Dominiak, Marzena

2016-01-01

The most common adverse effect after bone cutting is a thermal damage. The aim of our study was to evaluate the bone temperature rise during an alveolar ridge splitting, rating the time needed to perform this procedure and the time to raise the temperature of a bone by 10°C, as well as to evaluate the bone carbonization occurrence. The research included 60 mandibles (n = 60) of adult pigs, divided into 4 groups (n = 15). Two vertical and one horizontal cut have been done in an alveolar ridge using Er:YAG laser with set power of 200 mJ (G1), 400 mJ (G2), piezosurgery unit (G3), and a saw (G4). The temperature was measured by K-type thermocouple. The highest temperature gradient was noted for piezosurgery on the buccal and lingual side of mandible. The temperature rises on the bone surface along with the increase of laser power. The lower time needed to perform ridge splitting was measured for a saw, piezosurgery, and Er:YAG laser with power of 400 mJ and 200 mJ, respectively. The temperature rise measured on the bone over 10°C and bone carbonization occurrence was not reported in all study groups. Piezosurgery, Er:YAG laser (200 mJ and 400 mJ), and surgical saw are useful and safe tools in ridge splitting surgery. PMID:27957502

Assessment of Temperature Rise and Time of Alveolar Ridge Splitting by Means of Er:YAG Laser, Piezosurgery, and Surgical Saw: An Ex Vivo Study.

PubMed

Matys, Jacek; Flieger, Rafał; Dominiak, Marzena

2016-01-01

The most common adverse effect after bone cutting is a thermal damage. The aim of our study was to evaluate the bone temperature rise during an alveolar ridge splitting, rating the time needed to perform this procedure and the time to raise the temperature of a bone by 10°C, as well as to evaluate the bone carbonization occurrence. The research included 60 mandibles ( n = 60) of adult pigs, divided into 4 groups ( n = 15). Two vertical and one horizontal cut have been done in an alveolar ridge using Er:YAG laser with set power of 200 mJ (G1), 400 mJ (G2), piezosurgery unit (G3), and a saw (G4). The temperature was measured by K-type thermocouple. The highest temperature gradient was noted for piezosurgery on the buccal and lingual side of mandible. The temperature rises on the bone surface along with the increase of laser power. The lower time needed to perform ridge splitting was measured for a saw, piezosurgery, and Er:YAG laser with power of 400 mJ and 200 mJ, respectively. The temperature rise measured on the bone over 10°C and bone carbonization occurrence was not reported in all study groups. Piezosurgery, Er:YAG laser (200 mJ and 400 mJ), and surgical saw are useful and safe tools in ridge splitting surgery.

External macro- and micromorphology of the male of the stick insect Hermarchus leytensis (Insecta: Phasmatodea) with phylogenetic considerations.

PubMed

Gottardo, Marco; Vallotto, Davide

2014-04-01

External morphological features of adult males are described in the stick insect Hermarchus leytensis from the Philippines, a species belonging to the little-known euphasmatodean lineage Stephanacridini. Mouthparts are characterized by some likely specialized features: (1) a dentate dorsal cutting edge on the mandibles; (2) distinct differences in size and shape between the galeae; (3) absence of an apical field of trichomes on the galeae; and (4) lacinial setae not protruding from the mesal margin, which features three bearing-like protuberances. The latter character state represents a very unusual condition, not known in other phasmatodeans or even in polyneopteran insects. A distinctive characteristic of attachment devices is that each euplantula is divided into two separated pads with a smooth microstructure, as it also occurs in some members of the clade Schizodecema. Male terminalia exhibit character states previously unknown in Stephanacridini, including (1) a symmetrical type of vomer and (2) claspers equipped with ∼ 70 very minute ventral teeth on each thorn pad. Potential implications for the systematic placement of H. leytensis are discussed. The results also underline the importance of microanatomical investigations as source of substantial characters for future analyses on phasmatodean systematics. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Fixation of fractures of the condylar head of the mandible with a new magnesium-alloy biodegradable cannulated headless bone screw.

PubMed

Leonhardt, H; Franke, A; McLeod, N M H; Lauer, G; Nowak, A

2017-07-01

It is difficult to fix fractures of the condylar head of the mandible. Several techniques have been described which show satisfactory outcomes, but stability can be questionable, and some can cause irritation of the soft tissues. We describe a technique and first results of treating such fractures with resorbable magnesium-based headless bone screws (Magnezix ® 2.7mm CS; Syntellix AG, Hanover, Germany). Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

[Proprioceptive sensitivity and orofacial functions].

PubMed

Auriol, M; Coutand, A; Crinetz, V; Chomette, G; Doumit, A; Lucht, M

1985-01-01

Proprioceptive sensibility from stimulation of muscle, ligament articular and vestibular receptors plays a determining role in the regulation of tone, of the resting position of the mandible, of head posture and of the closure pathway of the mandible. Studies conducted on temporomandibular joints of fetuses and adult subjects failed to demonstrate the specialized corpuscles (a fact previously noted by Ramfjord) in the temporomaxillary joint capsule, described typically in other joints. In contrast, however, histology showed a particularly rich population of muscle receptors adjacent to this joint, this being only one of several particular characteristics.

Principles of pediatric mandibular fracture management.

PubMed

Cole, Patrick; Kaufman, Yoav; Izaddoost, Shayan; Hatef, Daniel A; Hollier, Larry

2009-03-01

Mandible fractures are commonplace in today's craniofacial practice; however, managing the infrequent, operative pediatric mandible injury requires a thorough knowledge base and thoughtful approach. Not only do these patients demonstrate variable anatomy due to differing stages of dental eruption, but condylar disruption may translate into long-term growth disturbance. In addition, patient immaturity often complicates cooperation, and both fixation strategies and postoperative planning must take this into account. As a supplement to the authors' video presentation, the present article focuses on repair of the symphyseal fracture and bilateral condylar injuries in the pediatric patient.

Fusions within the mandible of the domestic fowl (Gallus gallus domesticus).

PubMed Central

Hogg, D A

1983-01-01

The articulations formed within the mandible of the domestic fowl by its constituent elements have been described and illustrated. The sutures identified were suturae angulosplenialis, angulosupra-angularis, articulare/pre-articulo-angularis, articulare/pre-articulosupra-angularis, dento-angularis, dentosplenialis, dentosupra-angularis and supra-angulosplenialis. Some degree of fusion was found to occur in all sutures except sutura supra-angulosplenialis. The range of fusion time and mean fusion time for each site was studied in a flock of Golden Comet pullets. Mean fusion times varied from 45-119 days post-hatching. PMID:6885616

Fusions within the mandible of the domestic fowl (Gallus gallus domesticus).

PubMed

Hogg, D A

1983-05-01

The articulations formed within the mandible of the domestic fowl by its constituent elements have been described and illustrated. The sutures identified were suturae angulosplenialis, angulosupra-angularis, articulare/pre-articulo-angularis, articulare/pre-articulosupra-angularis, dento-angularis, dentosplenialis, dentosupra-angularis and supra-angulosplenialis. Some degree of fusion was found to occur in all sutures except sutura supra-angulosplenialis. The range of fusion time and mean fusion time for each site was studied in a flock of Golden Comet pullets. Mean fusion times varied from 45-119 days post-hatching.

Technical report: precisely fitting bars on implants in five steps-a CAD/CAM concept for the edentulous mandible.

PubMed

Beuer, Florian; Schweiger, Josef; Huber, Martin; Engels, Jörg; Stimmelmayr, Michael

2014-06-01

Various treatment concepts have been presented for the edentulous mandible. Manufacturing tension-free and precisely fitting bars on dental implants was previously a great challenge in prosthetic dentistry and required great effort. Modern computer aided design/computer aided manufacturing technology in combination with some clinical modifications of the established workflow enables the clinician to achieve precise results in a very efficient way. The innovative five-step concept is presented in a clinical case. © 2014 by the American College of Prosthodontists.

Oral cancer: A multicenter study

PubMed Central

Rojanawatsirivej, Somsri; Thosaporn, Watcharaporn; Kintarak, Sompid; Subarnbhesaj, Ajiravudh; Darling, Mark; Kryshtalskyj, Eugene; Chiang, Chun-Pin; Shin, Hong-In; Choi, So-Young; Lee, Sang-shin; Shakib, Pouyan-Amini

2018-01-01

Background To determine the prevalence and clinicopathologic features of the oral cancer patients. Material and Methods Biopsy records of the participating institutions were reviewed for oral cancer cases diagnosed from 2005 to 2014. Demographic data and site of the lesions were collected. Sites of the lesion were subdivided into lip, tongue, floor of the mouth, gingiva, alveolar mucosa, palate, buccal/labial mucosa, maxilla and mandible. Oral cancer was subdivided into 7 categories: epithelial tumors, salivary gland tumors, hematologic tumors, bone tumors, mesenchymal tumors, odontogenic tumors, and others. Data were analyzed by descriptive statistics using SPSS software version 17.0. Results Of the 474,851 accessioned cases, 6,151 cases (1.30%) were diagnosed in the category of oral cancer. The mean age of the patients was 58.37±15.77 years. A total of 4,238 cases (68.90%) were diagnosed in males, whereas 1911 cases (31.07%) were diagnosed in females. The male-to-female ratio was 2.22:1. The sites of predilection for oral cancer were tongue, labial/buccal mucosa, gingiva, palate, and alveolar mucosa, respectively. The three most common oral cancer in the descending order of frequency were squamous cell carcinoma, non-Hodgkin lymphoma and mucoepidermoid carcinoma. Conclusions Although the prevalence of oral cancer is not high compared to other entities, oral cancer pose significant mortality and morbidity in the patients, especially when discovered late in the course of the disease. This study highlights some anatomical locations where oral cancers are frequently encountered. As a result, clinicians should pay attention to not only teeth, but oral mucosa especially in the high prevalence area as well since early detection of precancerous lesions or cancers in the early stage increase the chance of patient being cured and greatly reduce the mortality and morbidity. This study also shows some differences between pediatric and elderly oral cancer patients as well as between Asian and non-Asian oral cancer patients. Key words:Oral cancer, prevalence, clinic-pathologic features, retrospective study. PMID:29274153

A rare coexistence of aspergillosis with actinomycosis.

PubMed

Vinay, B Hari; Mohan, Aditya; Haritha, P; Lakshmi, K Roja

2017-01-01

Aspergillosis is a common systemic mycosis which affects immunocompromised and immunocompetent hosts. Aspergillus spp. is wide spread in the environment in most countries, which renders an invasive form of disease. The presence conidial heads are pathognomic to aspergillosis in diagnosis. Actinomycosis is a subacute-to-chronic infection that causes sinus fistula, tract or abscess due to the invasion surrounding the soft tissue. Cervicofacial infection accounts for 50%-60% of all actinomycosis cases. The mandible and nasopharynx are the sites of predilection, but maxillary infection is rare. Aspergillosis and Actinomycosis each of them was reported in case, but mixed infection of both organisms is rare, only one case has been reported. This paper discussed about a case report of coexistence of aspergillosis with actinomycosis in 38-year-old male.

[Noninvasive alternatives to CPAP in therapy of obstructive sleep apnea syndrome].

PubMed

Fritsch, K; Bloch, K E

2000-07-01

Non-surgical treatment of the sleep apnea syndrome comprises behavioral modification such as sleep hygiene, weight reduction, and positional training as an adjunct to standard therapy with continuous positive airway pressure (CPAP) applied via a nasal mask. For patients who cannot tolerate or are not willing to use CPAP for psychological or other reasons, removable intraoral appliances that advance the mandible during sleep are a valuable treatment alternative. Randomised controlled trials have confirmed effectiveness of intraoral appliances in relieving symptoms and measured sleep and respiratory disturbances. Side effects including hypersalivation, mucosal dryness, tooth and temporo-mandibular joint discomfort are common but usually mild. To timely detect effects of oral appliances on occlusion and on the temporo-mandibular joint longterm orthodontic monitoring is advisable.

Bilateral maxillary brown tumors in a patient with primary hyperparathyroidism: Report of a rare entity and review of literature

PubMed Central

Soundarya, N; Sharada, P; Prakash, Nilima; Pradeep, GL

2011-01-01

Brown tumors are erosive bony lesions caused by rapid osteoclastic activity and peritrabecular fibrosis due to hyperparathyroidism, resulting in a local destructive phenomenon. The classical “brown tumor” is commonly seen in ends of long bones, the pelvis and ribs. Facial involvement is rare and, when present, usually involves the mandible. We report a case of 60-year-old male with a rare initial presentation of primary hyperparathyroidism with bilateral maxillary brown tumors. The present case represents the third report of the bilateral maxillary brown tumors in a patient with primary hyperparathyroidism. Differential diagnosis is important for the right treatment choice. It should exclude other giant cell lesions that affect the maxillae. PMID:21731279

Analysis of facial bone fractures: An 11-year study of 2,094 patients

PubMed Central

Hwang, Kun; You, Sun Hye

2010-01-01

Purpose: The medical records of these patients were reviewed and analysed to determine the clinical characteristics and treatment of facial bone fractures. Patients and Methods: This is a retrospective study of 2,094 patients with facial bone fractures from various accidents that were treated at the Inha University Hospital from 1996 to 2007. Results: The most common age group was the third decade of life (29%). Males were more common than females (3.98:1). The most common aetiology was violent assault or nonviolent traumatic injury (49.4%). The most common isolated fracture site was the nasal bone (37.7%), followed by the mandible (30%), orbital bones (7.6%), zygoma (5.7%), maxilla (1.3%) and the frontal bone (0.3%). The largest group with complex fractures included the inferior region of the orbital floor and zygomaticomaxilla (14%). Closed reduction was performed in 46.3% of the cases while 39.7% of the cases required open reduction. For open reductions, the most commonly used soft-tissue approach was the intraoral approach (32.3%). The complication rate was 6.4% and the most common complication was hypoesthesia (68.4%) followed by diplopia (25.6%). Conclusion: Long-term collection of epidemiological data regarding facial fractures and concomitant injuries is important for the evaluation of existing preventive measures and useful in the development of new methods of injury prevention and treatment. PMID:20924449

High-frequency 3D echodentographic imaging modality for early assessment of periodontal diseases: in vitro study

NASA Astrophysics Data System (ADS)

Mahmoud, Ahmed M.; Ngan, Peter; Crout, Richard; Mukdadi, Osama M.

2009-02-01

The use of ultrasound in dentistry is still an open growing area of research. Currently, there is a lack of imaging modalities to accurately predict minute structures and defects in the jawbone. In particular, the inability of 2D radiographic images to detect bony periodontal defects resulted from infection of the periodontium. This study investigates the feasibility of high frequency ultrasound to reconstruct high resolution 3D surface images of human jawbone. Methods: A dentate and non-dentate mandibles were used in this study. The system employs high frequency single-element ultrasound focused transducers (15-30 MHz) for scanning. Continuous acquisition using a 1 GHz data acquisition card is synchronized with a high precision two-dimensional stage positioning system of +/-1 μm resolution for acquiring accurate and quantitative measurements of the mandible in vitro. Radio frequency (RF) signals are acquired laterally 44-45.5 μm apart for each frame. Different frames are reconstructed 500 μm apart for the 3D reconstruction. Signal processing algorithms are applied on the received ultrasound signals for filtering, focusing, and envelope detection before frame reconstruction. Furthermore, an edge detection technique is adopted to detect the bone surface in each frame. Finally, all edges are combined together in order to render a 3D surface image of the jawbone. Major anatomical landmarks on the resultant images were confirmed with the anatomical structures on the mandibles to show the efficacy of the system. Comparison were also made with conventional 2D radiographs to show the superiority of the ultrasound imaging system in diagnosing small defects in the lateral, axial and elevation planes of space. Results: The landmarks on all ultrasound images matched with those on the mandible, indicating the efficacy of the system in detecting small structures in human jaw bones. Comparison with conventional 2D radiographic images of the same mandible showed superiority of the 3D ultrasound images in detecting defects in the elevation plane of space. These results suggest that the high frequency ultrasound system shows great potential in providing a non-invasive method to characterize the jawbone and detect periodontal diseases at earlier stages.

Quantitative and qualitative assessment of anchorage loss during en-masse retraction with indirectly loaded miniscrews in patients with bimaxillary protrusion.

PubMed

Monga, Nitika; Kharbanda, Om Prakash; Samrit, Vilas

2016-08-01

This study provides vital insight in assessing anchorage loss when miniscrews are indirectly loaded. The study sample comprised 18 patients with bimaxillary protrusion (14 girls, 4 boys; mean age, 17.3 ± 4.6 years) selected from a database of 89 patients treated with miniscrews. All subjects who were selected required extraction of all first premolars and maximum anchorage. After initial leveling and aligning, miniscrews were placed between the first molar and the second premolar in all 4 quadrants and loaded by the indirect method at 3 weeks after placement with 200-g nickel-titanium alloy closed-coil springs for en-masse retraction. Mean treatment duration was 29.7 ± 6.8 months. Pretreatment and posttreatment lateral cephalograms were analyzed to measure the amount of anchorage loss, incisor retraction, and the incisors' angular change in reference to the pterygoid vertical reference line and were evaluated by the structural superimposition method. The ratio of incisor retraction to molar protraction was 4.2 in the maxilla and 4.7 in the mandible. The first molars showed mean extrusion of 0.20 mm in the maxilla and 0.57 mm in the mandible; these were statistically insignificant. The mean angular change of the first molars was -2.43° in the maxilla and -0.03° in the mandible. The mean anchorage loss in reference to the pterygoid vertical was 1.3 mm in the maxilla and 1.1 mm in the mandible; these were statistically significant. Structural superimpositions showed mean change in molar position of 0.83 mm in the maxilla and 0.87 mm in the mandible, and 5.77 mm in the maxillary incisor and 5.43 mm in the mandibular incisor. These results were compared with the direct anchorage method reported in the literature. Indirect miniscrew anchorage can be a viable alternative to direct anchorage. Copyright © 2016. Published by Elsevier Inc.

Immediate and early function of Brånemark System implants placed in the esthetic zone: a 1-year prospective clinical multicenter study.

PubMed

Maló, Paulo; Friberg, Bertil; Polizzi, Giovanni; Gualini, Federico; Vighagen, Torbjörn; Rangert, Bo

2003-01-01

Immediate/early implant function means great benefits for patients and therapists because treatment time and cost can be substantially reduced. This concept has become an accepted alternative for complete arch fixed restorations in the mandible, and clinical documentation is emerging for other indications. The purpose of this prospective clinical multicenter study was to evaluate the outcome of implants placed in incisor, canine, and premolar regions in maxillas or mandibles. Implants were loaded with provisional crowns and bridges on the same day or within a few days and were followed up for 1 year during function. Four centers treated 76 patients each in need of an implant-retained prosthesis in the anterior and premolar regions in the maxilla or mandible. A total of 116 titanium implants with machined surfaces (Brånemark System , Nobel Biocare AB, Gothenburg, Sweden) were placed: 74 in maxillas and 42 in mandibles. Eighty-seven prostheses were made, of which 63 were single crowns and 24 were bridges (supported by 53 splinted implants). Twenty-two implants in 14 patients were placed in fresh extraction sites. The goal with the preparation and insertion technique was to achieve good primary implant stability and a minimum implant insertion torque of 30 Ncm before the implant was completely seated. The occlusion was adjusted to eliminate direct contact with the provisional prostheses. After 6 months, the patients received their permanent prostheses. Sixty-seven patients were followed for 1 year. Five implants were lost in five patients, three in the maxilla and two in the mandible. Four of the lost implants were single-tooth replacements and one was splinted. The cumulative survival rate (CSR) was 95.7% for all implants after 1 year and 93.7% and 98.1% for single-tooth and splinted implants, respectively. There were no implant losses in the extraction sites. The CSR of 96% at 1 year indicates that immediate function of Brånemark System implants placed in incisor to premolar regions in both jaws is a viable concept. More failures occurred with single-tooth replacements (6.3%) than with splinted implants (1.9%).

Synchronous ossifying fibromas of the jaws: a review.

PubMed

Akcam, Timur; Altug, Hasan Ayberk; Karakoc, Omer; Sencimen, Metin; Ozkan, Aydin; Bayar, Gurkan Rasit; Gunhan, Omer

2012-11-01

According to the World Health Organization, it is proposed that benign fibro-osseous lesions be divided into 3 categories, including fibrous dysplasia, ossifying fibroma (OF), and osseous dysplasia. OF arises from the periodontal ligament, which contains multipotential cells. These benign tumors may become large and aggressive. Slow growth and lack of symptoms are the cardinal features. OF tends to occur in the second and third decades of life, with predilection for women and for the mandibular premolar-molar area. The method of treatment used for large or rapidly expanding lesions is surgical removal (enucleation). Rarely, OFs occur multifocally. We report a 20-year-old man with synchronous OFs of his maxilla and mandible and review other synchronous cases reported. Such lesions can be properly diagnosed and treated by correlating radiographic, clinical, surgical, and histopathologic findings. Copyright © 2012 Elsevier Inc. All rights reserved.

Prosthetic treatment of oligodontia with a tooth-supported overdenture--a case report.

PubMed

Akeredolu, P A

2002-01-01

An unusual case of oligodontia is reported in a 20 year old Nigerian male. It is unusual because of the isolated occurrence of the oligodontia which is unassociated with a family history or any other clinical features suggestive of specific syndromes or severe systemic abnormality. The patient presented with conically or peg shaped anterior and malformed posterior teeth in both the maxilla and mandible. Full mouth periapical radiographs revealed stunted roots, widening of the periodontal space and an unerupted tooth in the right mandibular premolar region. Tooth-supported upper and lower removable partial overdenture were fabricated for him. This modality of treatment is a better choice which helps not only to preserve the alveolar ridge height and improve aesthetics, but also preserves the proprioceptive mechanisms associated with the periodontal membrane of natural teeth.

Soft-tissue facial characteristics of attractive Chinese men compared to normal men.

PubMed

Wu, Feng; Li, Junfang; He, Hong; Huang, Na; Tang, Youchao; Wang, Yuanqing

2015-01-01

To compare the facial characteristics of attractive Chinese men with those of reference men. The three-dimensional coordinates of 50 facial landmarks were collected in 40 healthy reference men and in 40 "attractive" men, soft tissue facial angles, distances, areas, and volumes were computed and compared using analysis of variance. When compared with reference men, attractive men shared several similar facial characteristics: relatively large forehead, reduced mandible, and rounded face. They had a more acute soft tissue profile, an increased upper facial width and middle facial depth, larger mouth, and more voluminous lips than reference men. Attractive men had several facial characteristics suggesting babyness. Nonetheless, each group of men was characterized by a different development of these features. Esthetic reference values can be a useful tool for clinicians, but should always consider the characteristics of individual faces.

Variation in arterial supply to the floor of the mouth and assessment of relative hemorrhage risk in implant surgery.

PubMed

Katsumi, Yuji; Tanaka, Ray; Hayashi, Takafumi; Koga, Taketo; Takagi, Ritsuo; Ohshima, Hayato

2013-04-01

Bleeding in the floor of the mouth during implant surgery is attributed to arterial injuries in the sublingual space: clinicians may injure the submental and sublingual arteries, which originate from the facial and lingual arteries, respectively. This study aimed to clarify the three-dimensional courses of submental and sublingual arteries and their topographic relation to the mandible. During the gross anatomy course at the Faculty of Dentistry and Graduate School, Niigata University (2009-2011), we investigated the relationship between the courses of submental and sublingual arteries and their dividing patterns of the mylohyoid muscle, sublingual gland, and mandible using 27 human cadavers. The courses of submental and sublingual arteries were divided into four patterns: (1) the sublingual space was supplied by the sublingual artery (type I: 63%), (2) it was supplied by both the sublingual and submental arteries (type II: 5.6%), (3) it was supplied by the submental artery without the sublingual artery (type III: 29.6%), and (4) type III without the deep lingual artery originated from the lingual artery (type IV: 1.8%). In type II, III, and IV, the submental artery perforates the mylohyoid muscle or takes a roundabout route to travel near the surface of the mandible. The percentage occurrence of arteries traveling between the sublingual gland and mandible in type II, III, and IV (55%) is higher than that in type I (8.8%). Susceptibility of the submental artery in type II, III, and IV to injury during implant surgery is suggested. © 2011 John Wiley & Sons A/S.

Chromosomal rearrangements, phenotypic variation and modularity: a case study from a contact zone between house mouse Robertsonian races in Central Italy.

PubMed

Franchini, Paolo; Colangelo, Paolo; Meyer, Axel; Fruciano, Carmelo

2016-03-01

The Western European house mouse, Mus musculus domesticus, is well-known for the high frequency of Robertsonian fusions that have rapidly produced more than 50 karyotipic races, making it an ideal model for studying the mechanisms of chromosomal speciation. The mouse mandible is one of the traits studied most intensively to investigate the effect of Robertsonian fusions on phenotypic variation within and between populations. This complex bone structure has also been widely used to study the level of integration between different morphogenetic units. Here, with the aim of testing the effect of different karyotypic assets on the morphology of the mouse mandible and on its level of modularity, we performed morphometric analyses of mice from a contact area between two highly metacentric races in Central Italy. We found no difference in size, while the mandible shape was found to be different between the two Robertsonian races, even after accounting for the genetic relationships among individuals and geographic proximity. Our results support the existence of two modules that indicate a certain degree of evolutionary independence, but no difference in the strength of modularity between chromosomal races. Moreover, the ascending ramus showed more pronounced interpopulation/race phenotypic differences than the alveolar region, an effect that could be associated to their different polygenic architecture. This study suggests that chromosomal rearrangements play a role in the house mouse phenotypic divergence, and that the two modules of the mouse mandible are differentially affected by environmental factors and genetic makeup.

The morphology of the mandibular coronoid process does not indicate that Canis lupus chanco is the progenitor to dogs.

PubMed

Janssens, Luc; Miller, Rebecca; Van Dongen, Stefan

The domestication of wolves is currently under debate. Where, when and from which wolf sub-species dogs originated are being investigated both by osteoarchaeologists and geneticists. While DNA research is rapidly becoming more active and popular, morphological methods have been the gold standard in the past. But even today morphological details are routinely employed to discern archaeological wolves from dogs. One such morphological similarity between Canis lupus chanco and dogs was published in 1977 by Olsen and Olsen. This concerns the "turned back" anatomy of the dorsal part of the vertical ramus of the mandible that was claimed to be specific to domestic dogs and Chinese wolves C . lupus chanco , and "absent from other canids". Based on this characteristic, C . lupus chanco was said to be the progenitor of Asian and American dogs, and this specific morphology has been continuously used as an argument to assign archaeological specimens, including non-Asian and non-American, to the dog clade. We challenged this statement by examining 384 dog skulls of 72 breeds and 60 skulls of four wolf sub-species. Only 20 % of dog mandibles and 80 % of C . lupus chanco showed the specific anatomy. In addition, 12 % of Canis lupus pallipes mandibles showed the "turned back" morphology. It can be concluded that the shape of the coronoid process of the mandible cannot be used as a morphological trait to determine whether a specimen belongs to a dog or as an argument in favour of chanco as the progenitor to dogs.

Evaluation of Mandibular Anatomy Associated With Bad Splits in Sagittal Split Ramus Osteotomy of Mandible.

PubMed

Wang, Tongyue; Han, Jeong Joon; Oh, Hee-Kyun; Park, Hong-Ju; Jung, Seunggon; Park, Yeong-Joon; Kook, Min-Suk

2016-07-01

This study aimed to identify risk factors associated with bad splits during sagittal split ramus osteotomy by using three-dimensional computed tomography. This study included 8 bad splits and 47 normal patients without bad splits. Mandibular anatomic parameters related to osteotomy line were measured. These included anteroposterior width of the ramus at level of lingula, distance between external oblique ridge and lingula, distance between sigmoid notch and inferior border of mandible, mandibular angle, distance between inferior outer surface of mandibular canal and inferior border of mandible under distal root of second molar (MCEM), buccolingual thickness of the ramus at level of lingula, and buccolingual thickness of the area just distal to first molar (BTM1) and second molar (BTM2). The incidence of bad splits in 625 sagittal split osteotomies was 1.28%. Compared with normal group, bad split group exhibited significantly thinner BTM2 and shorter sigmoid notch and inferior border of mandible (P <0.05). However, for BTM1 and buccolingual thickness of the ramus at level of lingula, there was no statistical difference between the 2 groups. Mandibular angle, anteroposterior width of the ramus at level of lingula, external oblique ridge and lingula, and MCEM were not significantly different between the groups. This study suggests that patients with shorter ramus and low thickness of the buccolingual alveolar region distal to the second molar had a higher risk of bad splits. These anatomic data may help surgeons to choose the safest surgical techniques and best osteotomy sites.

3D visualization and quantification of bone and teeth mineralization for the study of osteo/dentinogenesis in mice models

NASA Astrophysics Data System (ADS)

Marchadier, A.; Vidal, C.; Ordureau, S.; Lédée, R.; Léger, C.; Young, M.; Goldberg, M.

2011-03-01

Research on bone and teeth mineralization in animal models is critical for understanding human pathologies. Genetically modified mice represent highly valuable models for the study of osteo/dentinogenesis defects and osteoporosis. Current investigations on mice dental and skeletal phenotype use destructive and time consuming methods such as histology and scanning microscopy. Micro-CT imaging is quicker and provides high resolution qualitative phenotypic description. However reliable quantification of mineralization processes in mouse bone and teeth are still lacking. We have established novel CT imaging-based software for accurate qualitative and quantitative analysis of mouse mandibular bone and molars. Data were obtained from mandibles of mice lacking the Fibromodulin gene which is involved in mineralization processes. Mandibles were imaged with a micro-CT originally devoted to industrial applications (Viscom, X8060 NDT). 3D advanced visualization was performed using the VoxBox software (UsefulProgress) with ray casting algorithms. Comparison between control and defective mice mandibles was made by applying the same transfer function for each 3D data, thus allowing to detect shape, colour and density discrepencies. The 2D images of transverse slices of mandible and teeth were similar and even more accurate than those obtained with scanning electron microscopy. Image processing of the molars allowed the 3D reconstruction of the pulp chamber, providing a unique tool for the quantitative evaluation of dentinogenesis. This new method is highly powerful for the study of oro-facial mineralizations defects in mice models, complementary and even competitive to current histological and scanning microscopy appoaches.

Regenerate Healing Outcomes in Unilateral Mandibular Distraction Osteogenesis Using Quantitative Histomorphometry

PubMed Central

Schwarz, Daniel A.; Arman, Krikor G.; Kakwan, Mehreen S.; Jamali, Ameen M.; Elmeligy, Ayman A.; Buchman, Steven R.

2015-01-01

Background The authors’ goal was to ascertain regenerate bone-healing metrics using quantitative histomorphometry at a single consolidation period. Methods Rats underwent either mandibular distraction osteogenesis (n=7) or partially reduced fractures (n=7); their contralateral mandibles were used as controls (n=11). External fixators were secured and unilateral osteotomies performed, followed by either mandibular distraction osteogenesis (4 days’ latency, then 0.3 mm every 12 hours for 8 days; 5.1 mm) or partially reduced fractures (fixed immediately postoperatively; 2.1 mm); both groups underwent 4 weeks of consolidation. After tissue processing, bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, and osteocyte count per high-power field were analyzed by means of quantitative histomorphometry. Results Contralateral mandibles had statistically greater bone volume/tissue volume ratio and osteocyte count per high-power field compared with both mandibular distraction osteogenesis and partially reduced fractures by almost 50 percent, whereas osteoid volume/tissue volume ratio was statistically greater in both mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles. No statistical difference in bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, or osteocyte count per high-power field was found between mandibular distraction osteogenesis specimens and partially reduced fractures. Conclusions The authors’ findings demonstrate significantly decreased bone quantity and maturity in mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles using the clinically analogous protocols. If these results are extrapolated clinically, treatment strategies may require modification to ensure reliable, predictable, and improved outcomes. PMID:20463629

Analysis of complications following augmentation with cancellous block allografts.

PubMed

Chaushu, Gavriel; Mardinger, Ofer; Peleg, Michael; Ghelfan, Oded; Nissan, Joseph

2010-12-01

Bone grafting may be associated with soft and hard tissue complications. Recipient site complications encountered using cancellous block allografts for ridge augmentation are analyzed. A total of 101 consecutive patients (62 females and 39 males; mean age 44 ± 17 years) were treated with implant-supported restoration of 137 severe atrophic alveolar ridges augmented with cancellous bone-block allografts. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58); posterior maxilla (n = 32 sinuses); posterior mandible (n = 32); and anterior mandible (n = 15). A total of 271 rough-surface implants were placed. Recipient site complications associated with block grafting (infection, membrane exposure, incision line opening, perforation of mucosa over the grafted bone, partial graft failure, total graft failure, and implant failure) were recorded. Partial and total bone-block graft failure occurred in 10 (7%) and 11 (8%) of 137 augmented sites, respectively. Implant failure rate was 12 (4.4%) of 271. Soft tissue complications included membrane exposure (42 [30.7%] of 137); incision line opening (41 [30%] of 137); and perforation of the mucosa over the grafted bone (19 [14%] of 137). Infection of the grafted site occurred in 18 (13%) of 137 bone blocks. Alveolar ridge deficiency location had a statistically significant effect on the outcome of recipient site complications. More complications were noted in the mandible compared to the maxilla. Age and gender had no statistically significant effect. Failures caused by complications were rarely noted in association with cancellous block grafting. The incidence of complications in the mandible was significantly higher. Soft tissue complications do not necessarily result in total loss of cancellous block allograft.

Surgical Treatment for Extracapsular Condylar Fractures of the Mandible.

PubMed

Closs Ono, Maria C; de Morais, André D; Freitas, Renato da S; de Oliveira E Cruz, Gilvani A

2018-02-26

Condylar fractures are considered the most controversial mandibular fractures, regarding both the diagnosis and the treatment. With the increase in surgical indications for handling this type of fracture, it is important to discuss about the advantages and disadvantages of the several surgical approaches available. This article describes the surgical details and postoperative results of the mini-retromandibular transparotid approach for treating extracapsular condylar fractures of the mandible. In a 1-year period, 16 patients affected by extracapsular condylar fractures with surgical indication were treated with the mini-retromandibular transparotid approach. All the surgeries were executed by the same surgeon. Preoperative and postoperative details of each patient were analyzed. In the postoperatory, only 2 patients had purulent drainage in the associated fractures area and only 1 patient had paresis of the buccal branch of the facial nerve. No scar issues concerning the surgical wound were observed and reintervention was not necessary in any of the patients. The mini-retromandibular transparotid approach offers advantages and should be included as an option for the open treatment of extracapsular condylar fractures of the mandible.

The effect of range and ammunition type on fracture patterns in porcine postcranial flat bones.

PubMed

Fragkouli, Kleio; Al Hakeem, Eyad; Bulut, Ozgur; Simmons, Tal

2018-01-01

Pig half-carcasses were shot in scapulae, ribs and mandibles with either 0.243 hunting rifle using high velocity expanding ammunition (N = 30) or AK47 using full metal jacketed (FMJ) ammunition (N = 12) from a range of either 5 or 20 m. Fracture patterns related to distance of fire and ammunition type were compared on de-fleshed, macerated, and reconstructed bones. For expanding ammunition, location of fracture on ribs affected the resulting pattern. Scapulae shot from 5 m presented a comminuted pattern different from those shot from 20 m. Mandibles shot from 20 m showed a characteristic radiating pattern at entrance with the opposite ramus un-fractured; those shot from 5 m exhibited fractures to both rami. Using decision tree analysis provided accuracies of 93.8% for scapulae and 87.5% for mandibles. For FMJ, no distance dependent fracture differences were apparent in any bone. Decision tree analysis facilitated the interpretation of fracture patterns caused by projectile trauma. Copyright © 2017. Published by Elsevier Ltd.

Sub-Periosteal Dissection with Denture-Guided Epithelial Regeneration: A Novel Method for Peri-Implant Soft Tissue Management in Reconstructed Mandibles.

PubMed

Kumar, Vinay V; Jacob, P C; Kuriakose, Moni A

2016-12-01

In patients with reconstructed mandibles using free fibula flaps, management of soft tissues around implants supporting dental rehabilitation, is often a clinical problem. The aim of this paper is to describe a new technique, namely "Sub-periosteal dissection and denture-guided epithelial regeneration (SD-DGER)", as a method of peri-implant soft tissue management in these patients. The technique consists of performing a subperiosteal dissection with creation of buccal and lingual flaps. These flaps form the buccal and lingual vestibule. Implants are placed and an interim denture is immediately loaded onto the implants to guide the regenerated epithelium. A keratinized mucosal layer is formed on the bare fibula bone in six months time. This technique was successful in producing fixed keratinized epithelial tissue around implants in patients with mandibles reconstructed using the free fibula flap in patients who did not undergo radiotherapy. The sub-periosteal dissection with denture guided epithelial regeneration is a predictable form of peri-implant soft tissue management in selected patients with reconstructed jaws.

Evaluation of bone density in the mandibles of young Australian adults of Mongoloid and Caucasoid descent.

PubMed

Ong, R G; Stevenson, M R

1999-01-01

To evaluate the bone density in the mandibles of young Australian adults of Mongoloid and Caucasoid descent. A panoramic radiograph (Orthophos C, Siemens AG, Bensheim, Germany) was obtained of 79 dental students from the School of Oral Health Sciences, The University of Western Australia. Exposure factors were varied for males and females. The films were automatically processed in a single batch and the optical density measured blindly at two locations by two examiners. The optical density was compared by race and sex to detect bone density differences. Individual lifestyle habits (exercise, alcohol consumption, smoking and diet) was recorded in a self-administered questionnaire. Multiple regression analysis was used to analyse the effects of physical, environmental and medical characteristics. The Mongoloid subjects were found to have approximately 20% higher bone density at the angle of mandible than Caucasoid subjects (P = 0.0094 for males, P = 0.0004 for females). Race is the most important variable associated with bone density. Mongoloid subjects should be given a higher exposure for panoramic radiography than that normally used for Caucasoid subjects.

[The influences of the stress distribution on the condylar cartilage surface by Herbst appliance under various bite reconstruction--a three dimensional finite element analysis].

PubMed

Hu, L; Zhao, Z; Song, J; Fan, Y; Jiang, W; Chen, J

2001-02-01

The distribution of stress on the surface of condylar cartilage was investigated. Three-dimensional model of the 'Temporomandibular joint mandible Herbst appliance system' was set up by SUPER SAP software (version 9.3). On this model, various bite reconstruction was simulated according to specified advanced displacement and vertical bite opening. The distribution of maximum and minimum principal stress on the surface of condylar cartilage were computerized and analyzed. When Herbst appliance drove the mandible forward, the anterior condyle surface was compressed while the posterior surface was drawn. The trend of stress on the same point on the condyle surface was consistent in various reconstruction conditions, but the trend of stress on various point were different in same reconstruction conditions. All five groups of bite reconstruction (3-7 mm advancement, 4-2 mm vertical bite opening of the mandible) designed by this study can be selected in clinic according to the patient's capability of adaptation, the extent of malocclusion and the potential and direction of growth.

Evaluation of mandibular angle ostectomy using three-dimensional finite element analysis.

PubMed

Song, Jian; Zhu, Songsong; Luo, En; Hu, Jing; Feng, Ge

2014-07-01

This study was designed to investigate the stress and the displacement distributions of the mandible after mandibular angle ostectomy (MAO) by means of three-dimensional finite element analysis. On the basis of a female patient with a prominent angle of the mandible, the finite element models were generated by helical computed tomography and related software and were analyzed under muscle forces and 3 kinds of biting conditions, including intercuspal position (ICP), incisal clenching (INC), and right unilateral molar clenching (RMOL). The mandibular stress and displacement distributions were analyzed by Abaqus software. In the model of MAO, the increased stress and the decreased displacement was found in ICP, INC, and RMOL at the area of mandibular angle. The stress and the displacement increased in ICP and RMOL, whereas the others remained unchanged in INC at the area of mandibular condylar neck. The results of this study have shown that MAO could alter biomechanical characteristics in the operated mandible, which suggested that a greater hit on face may lead to a higher incidence rate of condyle fracture and a lower incidence rate of angle fracture after MAO.

Digital reconstruction of the mandible of an adult Lesothosaurus diagnosticus with insight into the tooth replacement process and diet

PubMed Central

Knoll, Fabien; Bordy, Emese M.; de Kock, Michiel O.; Redelstorff, Ragna

2017-01-01

Fragmentary caudal ends of the left and right mandible assigned to Lesothosaurus diagnosticus, an early ornithischian, was recently discovered in the continental red bed succession of the upper Elliot Formation (Lower Jurassic) at Likhoele Mountain (Mafeteng District) in Lesotho. Using micro-CT scanning, this mandible could be digitally reconstructed in 3D. The replacement teeth within the better preserved (left) dentary were visualised. The computed tomography dataset suggests asynchronous tooth replacement in an individual identified as an adult on the basis of bone histology. Clear evidence for systematic wear facets created by attrition is lacking. The two most heavily worn teeth are only apically truncated. Our observations of this specimen as well as others do not support the high level of dental wear expected from the semi-arid palaeoenvironment in which Lesothosaurus diagnosticus lived. Accordingly, a facultative omnivorous lifestyle, where seasonality determined the availability, quality, and abundance of food is suggested. This would have allowed for adaptability to episodes of increased environmental stress. PMID:28265518

Sexual dimorphism and population variation in the adult mandible : Forensic applications of geometric morphometrics.

PubMed

Franklin, Daniel; O'Higgins, Paul; Oxnard, Charles E; Dadour, Ian

2007-03-01

This article forms part of an ongoing series of investigations designed to apply three-dimensional (3D) technology to problems in forensic anthropology. We report here on new morphometric data examining sexual dimorphism and population variation in the adult human mandible. The material is sourced from dissection hall subjects of South African and American origin consequently the sex and a statement of age are known for each individual. Thirty-eight bilateral 3D landmarks were designed and acquired using a Microscribe G2X portable digitizer. The shape analysis software morphologika (www.york.ac.uk/res/fme) is used to analyze the 3D coordinates of the landmarks. A selection of multivariate statistics is applied to visualize the pattern, and assess the significance of, shape variation between the sexes and populations. The determination of sex and identification of population affinity are two important aspects of forensic investigation. Our results indicate that the adult mandible can be used to identify both sex and population affinity with increased sensitivity and objectivity compared to standard analytical techniques.

Ecomorphology of parasite attachment: experiments with feather lice.

PubMed

Bush, Sarah E; Sohn, Edward; Clayton, Dale H

2006-02-01

The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

Kinematics and Mechanics analysis of trap-jaw ant Odontomachus monticola

NASA Astrophysics Data System (ADS)

Hao, Wenteng; Yao, Guang; Zhang, Xiangyu; Zhang, Deyuan

2018-03-01

Trap-jaw ants of the genus Odontomachus exhibit spectacularly rapid predatory and fugitive strikes. In order to reveal the extraordinary impact resistance of the apical teeth material, we analyzed the kinematics and mechanics of the closing mandibles. Odontomachus monticola is an Odontomachus species and extensive in China. We video-recorded jaw-strikes to measure the closing velocity and acceleration. The experimental results showed that O. monticola’s mandibles closed at a highest velocity of 35.42 m/s and a highest acceleration of 750,000 m/s2 within an average duration of 0.16 ms. In addition, in order to measure the strike force, we developed an extraordinary measuring method with poly (vinylidene fluoride) (PVDF) piezoelectric film. First, the dynamic calibration of the PVDF piezoelectric film was conducted, then the calibrated piezoelectric film was struck by O. monticola. Finally, the mandible strike force was calculated according to the calibration result and the output signal. The measurements results demonstrated that the strike force ranges from 102.2 N to 235.2 N, which is impressive contrast with O. monticola’s body weight.

Clinical importance of median mandibular flexure in oral rehabilitation: a review.

PubMed

Sivaraman, K; Chopra, A; Venkatesh, S B

2016-03-01

The mandible has a property to flex inwards around the mandibular symphysis with change in shape and decrease in mandibular arch width during opening and protrusion of the mandible. The mandibular deformation may range from a few micrometres to more than 1 mm. The movement occurs because of the contraction of lateral pterygoid muscles that pulls mandibular condyles medially and causes a sagittal movement of the posterior segments. This movement of mandible can have a profound influence on prognosis and treatment outcome for various restorative, endodontics, fixed, removable and implant-related prosthesis. The review unfolds the causes, importance and clinical implications of median mandibular flexure in oral rehabilitation. This review also highlights the appropriate preventive measures and techniques that should be adopted by clinicians to minimise the effect of flexural movement of the jaw during oral rehabilitation. This would not only help clinicians to achieve a good prosthesis with accurate fit and longevity but also maintain the health of the surrounding periodontal or periimplant gingival tissues and bone. © 2015 John Wiley & Sons Ltd.

A Bony Landmark 'RAI Triangle' to Prevent 'Misplaced and Misdirected' Medial Cut in SSRO.

PubMed

Rai, Kirthi Kumar; Arakeri, Gururaj; Khaji, Shahanavaj I

2011-03-01

'Rai triangle', a new anatomic landmark on the medial surface of the ramus of the mandible which when identified and taken into consideration, may have a definite advantage. This is especially in terms of performing the medial horizontal cut which is an important and integral part of the sagittal split ramus osteotomy so as to avoid a bad split. The objective of this article is to propose an easily identifiable bony land mark, which is closely related to lingula of mandible that may ease the procedure of osteotomy and avoid bad splits.