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Sample records for jaw edentulous partially

  1. Posterior partially edentulous jaws, planning a rehabilitation with dental implants

    PubMed Central

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-01

    AIM: To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning. PMID:25610852

  2. Immediate loading in partially and completely edentulous jaws: a review of the literature with clinical guidelines.

    PubMed

    De Bruyn, Hugo; Raes, Stefanie; Ostman, Pär-Olov; Cosyn, Jan

    2014-10-01

    warranted. Immediately loaded single implants have lower survival rates, of 85.7-100%, with no clear impact of occlusal contact. In fact, a meta-analysis demonstrated a five times higher risk of failure for immediately loaded single implants when compared with delayed loading. No study showed superior soft-tissue preservation or esthetics following immediate loading of single implants compared with other loading protocols. However, this finding may not imply that a provisional implant crown becomes redundant when soft-tissue conditioning is deemed necessary. Taking into account earlier factors for success, immediate loading in the partially edentulous jaw by means of a fixed prosthesis seems predictable in terms of implant survival (95.5-100%). However, there are no studies with data on soft-tissue parameters, esthetic aspects or patient-centered outcomes, and the available studies mainly relate to the load-carrying part of the dentition. Clinical studies focusing on these aspects of treatment outcome are clearly needed. High patient satisfaction is the most important advantage of immediate loading, especially during the early healing phase. In this context, one should also realize that studies have revealed comparable patient satisfaction in patients following delayed loading once their prosthesis is in place. In the decision-making process, this aspect should be properly discussed with the patient along with other advantages and disadvantages of immediate loading.

  3. The feasibility of immediately loading dental implants in edentulous jaws

    PubMed Central

    2016-01-01

    Purpose Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. Methods A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1–8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. Results A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Conclusions Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws. PMID:27588213

  4. One-step fixed edentulous implant impressions and maxillomandibular jaw relationships: technical note.

    PubMed

    Dario, L J

    1996-01-01

    A custom impression tray fabricated from the diagnostic wax-up of existing denture can be used to simultaneously record the final impression and the maxillomandibular jaw relationships for edentulous implant patients. The technique, which also involves a soldering index for the metallic substructure, is easy to perform and cost effective.

  5. Implant assisted ortho-surgery in edentulous jaws: a clinical report

    PubMed Central

    Khojasteh, Arash; Payaminia, Leila; Alikhasi, Marzieh

    2015-01-01

    Key Clinical Message The severely atrophy of jaws often complicates ideally oral reconstruction of esthetics and functionality, and necessitates different preprosthetic surgeries including bone grafting, ortho-surgery, and implant insertion. The mentioned procedures could be done within different approaches. This report describes the management of an edentulous case by implant insertion before orthognathic correction. PMID:26576273

  6. Evaluation of dental panoramic radiographic findings in edentulous jaws: A retrospective study of 743 patients "Radiographic features in edentulous jaws"

    PubMed Central

    Kose, Taha Emre; Cakir Karabas, Hulya; Ozcan, Ilknur

    2015-01-01

    PURPOSE The aim of this study was to determine the frequency of significant panoramic radiographic findings and eventual treatment requirements before conventional or implant supported prosthetic treatment in asymptomatic edentulous patients. MATERIALS AND METHODS A total of 743 asymptomatic edentulous patients were retrospectively evaluated using a digital panoramic system. We analyzed the radiographic findings, including impacted teeth, retained root fragments, foreign bodies, severe atrophy of the posterior maxillary alveolar bone, mucous retention cysts, soft tissue calcifications and radiopaque-radiolucent conditions. RESULTS Four-hundred-eighty-seven (65.6%) patients had no radiographic finding. A total of 331 radiographic findings were detected in 256 (34%) patients. In 52.9% (n=175) of these conditions, surgical treatment was required before application of implant-supported fixed prosthesis. However, before application of conventional removable prosthesis surgical treatment was required for 6% (n=20) of these conditions. CONCLUSION The edentulous patients who will have implant placement for implant-supported fixed prosthesis can frequently require additional surgical procedures to eliminate pathological conditions. PMID:26576254

  7. Partial Edentulism and its Association with Socio-Demographic Variables among Subjects Attending Dental Teaching Institutions, India

    PubMed Central

    Vadavadagi, Suneel V; Srinivasa, H; Goutham, G B; Hajira, Nausheen; Lahari, M; Reddy, G T Prasantha

    2015-01-01

    Background: Despite advances in preventive dentistry, edentulism is a major public health issues worldwide. Edentulism is an enervating and unrepairable condition and is described as the “final marker of disease burden for oral health.” The objectives of the present study are to determine the relationship between socio-demographic variables and partial edentulism, and to evaluate the prevalence of various classes of partial edentulism by using Kennedy’s classification. Materials and Methods: Cross-sectional, descriptive study was conducted in an institution, on randomly selected individuals. The study group included adult patients who attended the outpatient Department of Prosthodontics during February-April 2015 formed the study participants. Data were collected by using a pre-formed pro-forma and Chi-square test was used to explore the relationship between two variables. Results: A population comprised of 384 individuals between the age group of 18 and 35 years. Of these, 204 (53.12%) were males and 180 (46.88%) were females. Two hundred and eighty eight individuals were partially edentulous showing a prevalence rate of 75%. 51.04% of the study subjects were lost their teeth because of periodontol disease. 73.4% belonged to the upper middle class and 75.4% were in lower middle class in partially edentulous subjects. 45.8% had a fair oral hygiene status. Kennedy’s class III was the most common type of partial edentulism in upper jaw and lower. Conclusion: The present study concluded that prevalence of partial edentulism among the study population was high. They need community-based oral health programs to increase the awareness and reduce the risk of tooth loss. PMID:26668484

  8. The one-model technique: a new method for immediate loading with fixed prostheses in edentulous or potentially edentulous jaws.

    PubMed

    Biscaro, Leonello; Becattelli, Alberto; Poggio, Paola M; Soattin, Massimo; Rossini, Franco

    2009-06-01

    This article examines a new prosthetic procedure for the immediate loading of implants with a fixed prosthesis in edentulous or potentially edentulous arches. In these situations, one of the main problems associated with immediate loading is the transfer of diagnostic information to the master cast. This technique takes advantage of an acrylic resin transfer plate that enables transfer of the study cast information to the master cast. Without any intrasurgical impression or any recording of the maxillomandibular relationship during or after surgery, construction of an adequate esthetic and functional fixed prosthesis is possible on the basis of diagnostic information acquired in the presurgical phase. The methodology is always applicable when there is an indication for immediate loading of implants. The rationale and guidelines for the successful use of this technique in edentulous or potentially edentulous arches are discussed and illustrated with a clinical case.

  9. Evaluation of the Quantitative Accuracy of 3D Reconstruction of Edentulous Jaw Models with Jaw Relation Based on Reference Point System Alignment

    PubMed Central

    Li, Weiwei; Yuan, Fusong; Lv, Peijun; Wang, Yong; Sun, Yuchun

    2015-01-01

    Objectives To apply contact measurement and reference point system (RPS) alignment techniques to establish a method for 3D reconstruction of the edentulous jaw models with centric relation and to quantitatively evaluate its accuracy. Methods Upper and lower edentulous jaw models were clinically prepared, 10 pairs of resin cylinders with same size were adhered to axial surfaces of upper and lower models. The occlusal bases and the upper and lower jaw models were installed in the centric relation position. Faro Edge 1.8m was used to directly obtain center points of the base surface of the cylinders (contact method). Activity 880 dental scanner was used to obtain 3D data of the cylinders and the center points were fitted (fitting method). 3 pairs of center points were used to align the virtual model to centric relation. An observation coordinate system was interactively established. The straight-line distances in the X (horizontal left/right), Y (horizontal anterior/posterior), and Z (vertical) between the remaining 7 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test. Results The differences of the straight-line distances of the remaining 7 pairs of center points between the two methods were X: 0.074 ± 0.107 mm, Y: 0.168 ± 0.176 mm, and Z: −0.003± 0.155 mm. The results of paired t-test were X and Z: p >0.05, Y: p <0.05. Conclusion By using contact measurement and the reference point system alignment technique, highly accurate reconstruction of the vertical distance and centric relation of a digital edentulous jaw model can be achieved, which meets the design and manufacturing requirements of the complete dentures. The error of horizontal anterior/posterior jaw relation was relatively large. PMID:25659133

  10. Mouthguard: a new technique for the partially edentulous patient.

    PubMed

    Gialain, Ivan Onone; e Dias, Reinaldo Brito; Costa, Bruno; Coto, Neide Pena

    2014-10-01

    Over the last decades, several articles have corroborated the need of using mouthguards in sports activities, manufactured with ethylene vinyl acetate (EVA) as their main material. There are different mouthguards techniques used by dentists worldwide to prevent injuries. A technique has been developed to help athletes, especially the partially edentulous patients, who were not getting the proper protection. The mouthguard technique consists in making EVA fillings to improve the adjustment and esthetics of mouthguard used by athletes. It is the authors' conviction that the technique may prevent injuries in sports activities without impairing the athletes' safety and esthetics. PMID:24597821

  11. A retrospective multicenter evaluation of the survival rate of osseointegrated fixtures supporting fixed partial prostheses in the treatment of partial edentulism.

    PubMed

    van Steenberghe, D

    1989-02-01

    Whether the excellent prognosis of the osseointegration technique also applies for the rehabilitation of partially edentulous jaws was investigated through a multicenter retrospective study. Six centers from three continents participated in the study, which included 133 fixtures in 38 patients. Forty fixtures were installed in the upper jaw and 93 in the lower jaw. The observation time varied between 6 and 36 months after prosthetic reconstruction. Clinical evaluation included mobility measurement of the restorations and control of infectious or neurologic complication. Radiologically the absence of radiolucency around the fixtures was checked by a single observer who also calculated the distance between the marginal bone and the top of the fixture. Fifty-eight percent of the prostheses were connected to natural teeth. The success rate for the individual fixtures in the upper and lower jaws was 87% and 92%, respectively. The most failures occurred before the prosthetic rehabilitation. The mean maximum distance between the margin of the bone and the fixture-abutment junction was 2.5 mm. Since only two of the 53 fixed prostheses were lost during the observation period, and since most fixture losses occurred before the prosthetic phase of the treatment, this study supports the concept that osseointegrated prostheses can also be applied to the rehabilitation of partial edentulism.

  12. Effect of the additional installation of implants in the posterior region on the prognosis of treatment in the edentulous mandibular jaw.

    PubMed

    Miyamoto, Youji; Fujisawa, Kenji; Takechi, Masaaki; Momota, Yukihiro; Yuasa, Tetsuya; Tatehara, Seiko; Nagayama, Masaru; Yamauchi, Eiji

    2003-12-01

    The aim of this study was to elucidate the effect of the additional installation of implants in the posterior region on the prognosis of treatment in the edentulous mandibular jaw. Fifteen patients who had received implants (Brånemark system, Nobel Biocare, Gotebörg, Sweden) in the edentulous mandible and completed a 1-year follow-up after the fitting of implant-anchored fixed prostheses were selected. In seven patients (Group A), four or five implants were installed between the mental foramina, and in eight patients (Group P), one or two implants, one on each side, were installed in the posterior regions in addition to the implants between the foramina. All implants of both groups achieved osseointegration. In Group A, there was no implant loss after loading. Six implants were lost in five patients of Group P within 1 year after loading. All of them were located in the posterior region. To elucidate whether or not the failure rate of the implants in the posterior region of Group P after loading was especially high, the failures were also compared with 89 implants, which were installed in the posterior region of the mandibles to support implant-anchored fixed partial prosthesis, during the same period (Group C). The cumulative survival rate of the implants of Group P was 60%, while that of the implants of Group C was 100% (P<0.001). When the survival rates of posterior implants with the same length of the two groups were compared, there were significant differences for the 7- and 10-mm-length implants only. These data demonstrate that the posterior implants in Group P are at greater risk. Deformation of the mandible due to jaw movement was thought to be the most likely cause of the implant loss. Therefore, when such modified treatment is chosen, it should be performed with meticulous attention. PMID:15015949

  13. Main occluding area in partially edentulous patients: changes before and after implant treatment.

    PubMed

    Goto, T; Nishinaka, H; Kashiwabara, T; Nagao, K; Ichikawa, T

    2012-09-01

    The 'main occluding area', the location where food crushing occurs during the first stroke of mastication, is reported to be an important concept; however, it is currently limited to findings in individuals with normal dentition. The purpose of this study was to assess the changes in the location, area and bite force of the main occluding area before and after implant treatments. We enrolled 50 partially edentulous and 22 normally dentate subjects. To identify the location of the main occluding area, each subject was instructed to freely bite once on a dental stopping using the partially edentulous side or the normally dentate area. The location, occluding contact area and bite force of the main occluding area before and after the implant treatments were analysed. The main occluding area was located at a reproducible location in the partially edentulous and normally dentate subjects. This location was principally the first molar region, and for the partially edentulous patients with missing teeth in the molar regions, it moved from the premolar region to the first molar region after treatment. The occluding contact area and bite force for the main occluding area increased (P < 0·05) after the implant treatment in the partially edentulous patients with missing teeth in the molar regions. These results suggest that the main occluding area can be restored to the first molar region after implant treatment and may be an important factor in the assessment of prosthodontic treatment. PMID:22672204

  14. Management of long span partially edentulous maxilla with fixed removable denture prosthesis

    PubMed Central

    Jeyavalan, Mahilan I.; Narasimman, M.; Venkatakrishnan, C. J.; Philip, Jacob M.

    2012-01-01

    Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis. PMID:23293488

  15. Management of long span partially edentulous maxilla with fixed removable denture prosthesis.

    PubMed

    Jeyavalan, Mahilan I; Narasimman, M; Venkatakrishnan, C J; Philip, Jacob M

    2012-07-01

    Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis. PMID:23293488

  16. Cross-arch arrangement in complete denture prosthesis to manage an edentulous patient with oral submucous fibrosis and abnormal jaw relation

    PubMed Central

    Tambe, Abhijit; Patil, Sanjayagouda B; Bhat, Sudhakara; Badadare, Mokshada M

    2014-01-01

    A patient with oral submucous fibrosis and resorbed ridges poses a challenge for prosthodontic rehabilitation because of the limited mouth opening and fibrotic mucosa. The fabrication of prosthesis is very difficult due to abnormal jaw relations, influencing the long-term prognosis of the patient. To present a case of oral submucous fibrosis with severely resorbed edentulous ridges which was successfully managed by adopting a modified technique in fabricating a complete denture prosthesis. A 55-year-old female patient with completely edentulous maxillary and mandibular arches diagnosed with oral submucous fibrosis was rehabilitated with complete dentures by recording neutral zone for resorbed mandibular ridge and by arranging the posterior teeth in cross arch relation for compensation of the abnormal jaw relations. The cross-arch arrangement of posterior teeth provides a more stable and retentive complete denture prosthesis for patients with severely resorbed ridges and a wider mandibular arch. PMID:25239981

  17. Partial Edentulism and its Correlation to Age, Gender, Socio-economic Status and Incidence of Various Kennedy’s Classes– A Literature Review

    PubMed Central

    Krishnan, Chitra Shankar

    2015-01-01

    Partial edentulism, one or more teeth missing is an indication of healthy behaviour of dental practices in the society and attitude towards dental and oral care. The pattern of partial edentulism has been evaluated in many selected populations in different countries by different methods. Most of the studies have evaluated partial edentulism by surveying of Removable Partial Dentures (RPDs), patients visiting clinics, clinical records and population in particular locality. The objective of the study is to review the prevalence of partial edentulousness and its correlation to age,gender, arch predominance, socio economic factors and incidence of various Kennedy’s Classes. Key observations drawn from the review are as below. There is no gender correlation for partial edentulism.Prevalence of partial edentulism is more common in mandibular arch than maxillary arch.Younger adults have more Class III and IV RPDs. Elders have more distal extension RPDs Class I and II. PMID:26266237

  18. Implant Restoration of Edentulous Jaws with 3D Software Planning, Guided Surgery, Immediate Loading, and CAD-CAM Full Arch Frameworks

    PubMed Central

    De Riu, Giacomo; Pisano, Milena; Campus, Guglielmo; Tullio, Antonio

    2013-01-01

    Purpose. The aim of this study was to analyze the clinical and radiographic outcomes of 23 edentulous jaws treated with 3D software planning, guided surgery, and immediate loading and restored with CAD-CAM full arch frameworks. Materials and Methods. This work was designed as a prospective case series clinical study. Twenty patients have been consecutively rehabilitated with an immediately loaded implant supported fixed full prosthesis. A total of 120 fixtures supporting 23 bridges were placed. 117 out of 120 implants were immediately loaded. Outcome measures were implants survival, radiographic marginal bone levels and remodeling, soft tissue parameters, and complications. Results. 114 of 117 implants reached a 30 months follow-up, and no patients dropped out from the study. The cumulative survival rate was 97.7%; after 30 months, mean marginal bone level was 1.25 ± 0.31 mm, mean marginal bone remodeling value was 1.08 ± 0.34, mean PPD value was 2.84 ± 0.55 mm, and mean BOP value was 4% ± 2.8%. Only minor prosthetic complications were recorded. Conclusion. Within the limitations of this study, it can be concluded that computer-guided surgery and immediate loading seem to represent a viable option for the immediate rehabilitations of completely edentulous jaws with fixed implant supported restorations. This trial is registered with Clinicaltrials.gov NCT01866696. PMID:23983690

  19. Dental Erosion in a Partially Edentulous Patient with Gastroesophageal Reflux Disease: A Case Report

    PubMed Central

    PICOS, ALINA MONICA; PICOS, ANDREI; NICOARA, PETRA; CRAITOIU, MONICA M.

    2014-01-01

    Diseases such as gastroesophageal reflux disease (GERD), bulimia, anorexia, and extrinsic alimentary factors may cause dental erosion (DE). The minimally invasive therapeutic attitude preserves the remaining healthy tooth structure. In the earlier stages, the direct restoration of dental lesions is possible, using composite materials. In advanced stages of DE, prosthetic treatments are recommended for stable esthetic and functional results. We present a case of DE in a partially edentulous patient who benefited from a complex therapy. The prosthetic project of the case involves ceramic veneers associated with dental and implant supported fixed prosthesis for the restoration of esthetics, mastication, phonetics and their maintenance. PMID:26528037

  20. Digital approach to planning computer-guided surgery and immediate provisionalization in a partially edentulous patient.

    PubMed

    Arunyanak, Sirikarn P; Harris, Bryan T; Grant, Gerald T; Morton, Dean; Lin, Wei-Shao

    2016-07-01

    This report describes a digital approach for computer-guided surgery and immediate provisionalization in a partially edentulous patient. With diagnostic data obtained from cone-beam computed tomography and intraoral digital diagnostic scans, a digital pathway of virtual diagnostic waxing, a virtual prosthetically driven surgical plan, a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template, and implant-supported screw-retained interim restorations were realized with various open-architecture CAD/CAM systems. The optional CAD/CAM diagnostic casts with planned implant placement were also additively manufactured to facilitate preoperative inspection of the surgical template and customization of the CAD/CAM-fabricated interim restorations. PMID:26868961

  1. Jaw growth in the absence of teeth: the developmental morphology of edentulous mandibles using the p63 mouse mutant.

    PubMed

    Paradis, Mitchell R; Raj, Muhammad T; Boughner, Julia C

    2013-01-01

    Mammalian tooth and jaw development must be coordinated well enough that these systems continue to function together properly throughout growth, thus optimizing an animal's survival and fitness, as well as a species' success. The persistent question is how teeth and jaws remain developmentally and functionally viable despite sometimes monumental evolutionary changes to tooth and jaw shape and size. Here we used the p63 mouse mutant to test the effect of tooth development - or the lack thereof - on normal mandible developmental morphology. Using 3D geometric morphometrics, we compared for the first time mandible shape among mice with normal tooth and jaw development against p63 double knock-out mice, with failed tooth development but apparently normal jaw development. Mandible shape differed statistically between toothless (p63(-/-) ) and toothed (p63(+/-) , p63(+/+) ) mice as early as embryonic day (E) 18. As expected, most of the shape difference in the p63(-/-) mandibles was due to underdeveloped alveolar bone related to arrested odontogenesis in these E18-aged mice. Mandible shape did not differ statistically between p63(+/-) and p63(+/+) adult mice, which showed normal tooth development. Our results support the idea of a gene regulatory network that is exclusive to the mandible and independent of the dentition. This study also underscores the biomechanical impact of the teeth on the developing alveolar bone. Importantly, this work shows quantitatively that the p63 mutant is an apt model with which to study mandible morphogenesis in isolation of odontogenesis to clarify developmental relationships between the teeth and jaws.

  2. Comparative evaluation of chewing function with removable partial dentures and fixed prostheses supported by the single-crystal sapphire implant in the Kennedy Class II partially edentulous mandible.

    PubMed

    Akagawa, Y; Okane, H; Kondo, N; Tsuga, K; Tsuru, H

    1989-01-01

    Differential chewing function with removable partial dentures (RPDs) and fixed prostheses supported by the single-crystal sapphire implant was evaluated in five subjects with Kennedy Class II partially edentulous mandibles by means of electromyography. Rehabilitation with the single-crystal sapphire implant resulted in regular chewing patterns with a low variation coefficient and higher activity of chewing-side masticatory muscles compared to RPD rehabilitation. This difference in chewing function between the two rehabilitation modalities could be the result of differences in stability of occlusion and neurophysiologic feedback systems.

  3. The Effect of Ridge Expansion on Implant Stability in Narrow Partially Edentulous Ridges - A Preliminary Clinical Study

    PubMed Central

    Shaik, Latheef Saheb; Meka, Sridhar; Chakravarthi, Srinivas Pandi; Kolli, Naga Neelima Devi; Lingamaneni, Krishna Prasad; Avvaru, Susmita; Tiwari, Rahul

    2016-01-01

    Introduction Currently, dental treatments with better aesthetic results and less treatment time is more acceptable by the patients. Inadequate amount of bone for implant placement at functionally and aesthetically most appropriate position is a common problem. Aim To assess the effect of ridge expansion on implant stability in narrow partially edentulous ridges and to evaluate clinically and radiographically the success of dental implants, placed immediately following ridge expansion procedure. Material and Methods Ten participants (nine males, one female, average age - 28 years) with partial edentulism associated with narrow atrophic alveolar ridges with adequate height and willing to participate in the study were included. The ridge expansion was performed using osteotomes and simultaneous implant placement was done. A total of 10 implants were placed. Stability, achieved ridge width and radiographic crestal bone loss were assessed three months post-operatively. Results Three months follow-up revealed stable implants both clinically and radiographically. All 10 implants were surrounded by adequate amount of bone required for successful functional rehabilitation. Conclusion The study reveals that the technique of ridge expansion using osteotomes is successful in horizontal expansion, in cases of atrophic alveolar ridges thus, eliminating the need for more complex treatment as well as reduces the rehabilitation time along with improving the quality of bone support. PMID:27790575

  4. Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study

    PubMed Central

    2015-01-01

    Background. The aims of this study were to investigate the ridge contour anterior to the nasopalatine canal, and the difference between the incidences of the nasopalatine canal perforation in dentate and partially edentulous patients by cone-beam computed tomography. Methods. Cone-beam computed tomography scan images from 72 patients were selected from database and divided into dentate and partially edentulous groups. The configuration of the ridge anterior to the canal including palatal concavity depth, palatal concavity height, palatal concavity angle, bone height coronal to the incisive foramen, and bone width anterior to the canal was measured. A virtual implant placement procedure was used, and the incidences of perforation were evaluated after implant placement in the cingulum position with the long axis along with the designed crown. Results. Comparing with variable values from dentate patients, the palatal concavity depth and angle were greater by 0.9 mm and 4°, and bone height was shorter by 1.1 mm in partially edentulous patients, respectively. Bone width in edentulous patients was narrower than in dentate patients by 1.2 mm at incisive foramen level and 0.9 mm at 8 mm subcrestal level, respectively. After 72 virtual cylindrical implants (4.1 × 12 mm) were placed, a total of 12 sites (16.7%) showed a perforation and three-fourths occurred in partially edentulous patients. After replacing with 72 tapered implants (4.3 × 13 mm), only 6 implants (8.3%) broke into the canal in the partially edentulous patient group. Conclusions. The nasopalatine canal may get close to the implant site and the bone width anterior to the canal decreases after the central incisor extraction. The incidence of nasopalatine canal perforation may occur more commonly during delayed implant placement in central incisor missing patients. PMID:26557434

  5. Comparison of Brånemark fixture integration and short-term survival using one-stage or two-stage surgery in completely and partially edentulous mandibles.

    PubMed

    Collaert, B; De Bruyn, H

    1998-04-01

    The aim of this prospective study was to compare the clinical integration and survival of Brånemark fixtures when using the conventional 2-stage surgical procedure to 1-stage surgical approach in completely and partially edentulous mandibles. A total of 85 patients were consecutively treated for partial (n = 35) or complete (n = 50) mandibular edentulousness. Fixtures removed because of mobility, pain or infection were counted as failures. The first 10 patients of each group were selected for radiographical analysis of crestal bone changes 1 year after prosthesis insertion. In 33 patients with edentulous mandibles, 170 fixtures were placed in a 1-stage approach. In this group, 4 fixtures (2.4%) were lost prior to prosthetic restoration. Seventeen edentulous patients received a total of 70 fixtures in a 2-stage procedure. Out of these, 5 fixtures (7.1%) were lost at abutment connection. In 17 partially edentulous patients, 41 fixtures were inserted in a 1-stage approach. Two fixtures (5%) were lost in this group. Finally, 18 partially edentulous patients received a total of 49 fixtures in a 2-stage procedure. Out of these, 6 fixtures (12%) were lost at abutment connection. In total 313 of the 330 installed mandibular implants were loaded between 6 and 12 months (94.8% success). No further losses occurred in the implants functioning at least 1 year (267 implants) or at least 2 years (59 implants). Statistical analysis (Chi square test) revealed no difference in fixture survival between the treatment modalities. Radiographical analysis after 1 year of functional loading showed the typical bone resorption changes up to the most coronal implant thread in both modalities. Although this study pertains to relatively early loading of 2 years, the results seem to indicate that in the mandible a 1-stage surgical approach with Brånemark fixtures may be as predictable as the conventional 2-stage procedure.

  6. [Prosthetic rehabilitation of partially edentulous patients: fixed - removable - combined? Metal - ceramics - all - ceramics? Implants? Anything goes! Part 1: two example cases of a combined fixed-removable restoration].

    PubMed

    Schnabl, Dagmar

    2015-01-01

    After a careful diagnosis, treatment planning and pretreatment, two partially edentulous patients were restored partly by onlays, crowns and bridges, partly by removable prostheses. According to esthetic and functional demands all- and/or metal-ceramic restorations were used as well as cast frame prostheses with clasps or extracoronal attachments. PMID:25735004

  7. A Survey of Removable Partial Denture (RPD) Retentive Elements in Relation to the Type of Edentulism and Abutment Teeth Found in Commercial Laboratories, Athens, Greece

    PubMed Central

    Sotiriou, Michael; Zissis, Alcibiades

    2014-01-01

    Objective The aim of this survey was to record removable partial denture (RPD) retentive elements and abutment teeth in partially edentulous patients, identified in commercial laboratories in Athens, Greece. Material and Methods 628 master casts with the corresponding cast metal frameworks used in the construction of RPDs were evaluated. Casts were photographed to identify the number and position of existing teeth, the partial edentulism class and the retentive elements. Prevalence tables and the x2 test were used for the statistical analysis of the collected data (α=.05). Results There were 276 maxillary (43.9%) and 352 (56.1%) mandibular casts. Maxillary edentulism entailed almost a total absence of right third molars in 96.7% and left third molars 96.0% of casts, with lower rates for the first and second molars. Edentulism in the posterior mandible presented a similar pattern. The most profound findings concerning retentive elements were: 91.9% of the retainers used were clasps and the remaining 8.1% were attachments. Of the clasps used, 48.9% were of the Roach Τ type, a finding more common in Kennedy Class I as compared to other Kennedy Classes (p<0.01). The circumferential clasps accounted for 19.3% of the total clasps used, and it was less frequently presented (8.8%) in Kennedy I Classes (p<0.01). Conclusions Roach clasps were used in the majority of cases whereas RPI clasps and attachments were rarely used.

  8. Computer-guided implant surgery and immediate loading with a modifiable radiographic template in a patient with partial edentulism: A clinical report.

    PubMed

    Lanis, Alejandro; Padial-Molina, Miguel; Gamil, Rami; Alvarez del Canto, Orlando

    2015-09-01

    Computer-guided implant surgery in fresh extraction sites is an underdeveloped procedure. The presence of teeth that will be extracted makes the creation of an appropriate radiographic template for virtual simulation of the rehabilitation impossible. A modified radiographic template is presented to define a digital restorative simulation for the maxillary rehabilitation of a patient with partial edentulism. This modification enables 3-dimensional prosthetic virtual information in regions where teeth will be extracted.

  9. From Guided Surgery to Final Prosthesis with a Fully Digital Procedure: A Prospective Clinical Study on 15 Partially Edentulous Patients.

    PubMed

    Dolcini, Giorgio Andrea; Colombo, Marco; Mangano, Carlo

    2016-01-01

    Scope. To demonstrate guided implant placement and the application of fixed, implant-supported prosthetic restorations with a fully digital workflow. Methods. Over a 2-year period, all patients with partial edentulism of the posterior maxilla, in need of fixed implant-supported prostheses, were considered for inclusion in this study. The protocol required intraoral scanning and cone beam computed tomography (CBCT), the superimposition of dental-gingival information on bone anatomy, surgical planning, 3D-printed teeth-supported surgical templates, and modelling and milling of polymethylmethacrylate (PMMA) temporaries for immediate loading. After 3 months, final optical impression was taken and milled zirconia frameworks and 3D-printed models were fabricated. The frameworks were veneered with ceramic and delivered to the patients. Results. Fifteen patients were selected for this study. The surgical templates were stable. Thirty implants were placed (BTK Safe®, BTK, Vicenza, Italy) and immediately loaded with PMMA temporaries. After 3 months, the temporaries were replaced by the final restorations in zirconia-ceramic, fabricated with a fully digital process. At 6 months, none of the patients reported any biological or functional problems with the implant-supported prostheses. Conclusions. The present procedure for fully digital planning of implants and short-span fixed implant-supported restorations has been shown to be reliable. Further studies are needed to validate these results. PMID:27493665

  10. From Guided Surgery to Final Prosthesis with a Fully Digital Procedure: A Prospective Clinical Study on 15 Partially Edentulous Patients

    PubMed Central

    2016-01-01

    Scope. To demonstrate guided implant placement and the application of fixed, implant-supported prosthetic restorations with a fully digital workflow. Methods. Over a 2-year period, all patients with partial edentulism of the posterior maxilla, in need of fixed implant-supported prostheses, were considered for inclusion in this study. The protocol required intraoral scanning and cone beam computed tomography (CBCT), the superimposition of dental-gingival information on bone anatomy, surgical planning, 3D-printed teeth-supported surgical templates, and modelling and milling of polymethylmethacrylate (PMMA) temporaries for immediate loading. After 3 months, final optical impression was taken and milled zirconia frameworks and 3D-printed models were fabricated. The frameworks were veneered with ceramic and delivered to the patients. Results. Fifteen patients were selected for this study. The surgical templates were stable. Thirty implants were placed (BTK Safe®, BTK, Vicenza, Italy) and immediately loaded with PMMA temporaries. After 3 months, the temporaries were replaced by the final restorations in zirconia-ceramic, fabricated with a fully digital process. At 6 months, none of the patients reported any biological or functional problems with the implant-supported prostheses. Conclusions. The present procedure for fully digital planning of implants and short-span fixed implant-supported restorations has been shown to be reliable. Further studies are needed to validate these results. PMID:27493665

  11. Evaluation of quality of life in patients with total or partial edentulism treated with computer-assisted implantology.

    PubMed

    Bertossi, D; Rossetto, A; Piubelli, C; Rossini, N; Zanotti, G; Rodella, L F; Bissolotti, G; Colletti, G; Chiarini, L; Nocini, P F

    2013-08-01

    Aim: The study deals with a preliminary analysis that compares quality of life of a randomized sample of patients with total or partial edentulism rehabilitated through conventional implantology or computer-assisted implantology. Methods: The first group was treated with conventional implantology, while the second group was treated with NobelGuide™ computer-assisted implantology. every patient has filled up a questionnaire about quality of life in presurgical period (sf-361), in postsurgical period (sf-361; tiq2) and about the gratification after prosthetic treatment. the questionnaire has evaluated physical, general and psycho-emotive health parameter. Results: sf-36 has demonstrated an improvement in quality of life after computer-assisted surgery. tiq has revealed that patients symptoms in post-surgical week were inferior in quality and in quantity in NobelGuide™ technique. gratification questionnaire has demonstrated that quality of life improvement matches patient full satisfaction after the treatment. Conclusion: NobelGuide™ protocol improves physical health after implantology with positive reflections on psycho-emotive health. furthermore prefabricated temporary prostheses reduces treatment time and patient discomfort.

  12. Implant overdenture and Locator system in edentulous patient with severely resorbed mandible - a case report.

    PubMed

    Ionescu, Camelia; Gălbinaşu, Bogdan Mihai; Manolea, Horia; Pătraşcu, Ion

    2014-01-01

    Clinical studies have revealed that the main objective of implants in the edentulous jaw is to provide support for fixed prostheses or to stabilize complete dentures. Various attachment systems were developed for universal use in partially and completely edentulous patients such as clasps, cone-shape telescope copings, magnets, bar systems, locators. The aim of this case report is to present the Locator attachment that does not use the splinting of implants. Four implants were placed in the foraminal region and the Locator attachment system was used to connect overdentures to mandibular dental implants. The results proved that the Locator attachment system offers the possibility to obtain a higher retention and an improved stability for overdentures in edentulous patients with a severely resorbed mandible and lack of vertical space between the arches.

  13. A telescopic crown concept for the restoration of partially edentulous patients with aggressive generalized periodontitis: a 3-year prospective longitudinal study.

    PubMed

    Mengel, Reiner; Kreuzer, Gerd; Lehmann, Klaus M; Flores-de-Jacoby, Lavin

    2007-06-01

    This prospective longitudinal 3-year study compared clinical parameters and implant success rates of removable superstructures supported by both teeth and implants in patients with treated generalized aggressive periodontitis (GAP) and of cemented, implant-retained fixed superstructures in periodontally healthy patients. A total of 17 partially edentulous patients with 54 implants took part in the study. Nine patients with treated GAP received removable superstructures according to the Marburg double crown system, and eight periodontally healthy patients received fixed superstructures. Teeth were examined 2 to 4 weeks before extraction of the nonretainable teeth (baseline) and 3 weeks after insertion of the definitive abutments. Every 3 months over a 3-year period, clinical parameters were recorded and the composition of the subgingival microflora was determined. Intraoral radiographs were obtained at baseline, just after insertion of the superstructure, and 1 and 3 years later. Both groups showed mean plaque and gingival indices below 0.43 at implants and teeth. Mean probing depths around implants increased by approximately 0.7 mm and remained virtually constant for the teeth. Mean attachment loss at implants was 0.9 mm in GAP patients and 0.5 mm in healthy patients. The morphologic distribution of microorganisms in both groups showed healthy conditions. Moderate bone loss at teeth and implants was registered. Implant success rates were 100% in the healthy patients and 97.6% in the GAP patients. No significant differences were seen in the results between the groups.

  14. [Prosthetic rehabilitation of partially edentulous patients: fixed - removable - combined? Metal - ceramics - all - ceramics? Implants? Anything goes! Part 2: two case studies represent the fixed, respectively the combined fixed-removable prosthetic restoration by utilization of implants].

    PubMed

    Schnabl, Dagmar

    2015-01-01

    The prosthetic rehabilitation of two partially edentulous patients is presented: one Patient was restored by permanent crowns and bridges attached to natural teeth and to implants, the second was treated by crowns attached to natural teeth and removable implant- supported prostheses. Depending on esthetic requirements and the localization of preparation margins all- or metal-ceramics were used for single crowns, metal-ceramics was used for bridges. In general, a well coordinated cooperation of dentist, surgeon and dental technician in treatment planning and realization is required for a successful prosthetic rehabilitation. PMID:25734274

  15. [Prosthetic rehabilitation of partially edentulous patients: fixed - removable - combined? Metal - ceramics - all - ceramics? Implants? Anything goes! Part 2: two case studies represent the fixed, respectively the combined fixed-removable prosthetic restoration by utilization of implants].

    PubMed

    Schnabl, Dagmar

    2015-01-01

    The prosthetic rehabilitation of two partially edentulous patients is presented: one Patient was restored by permanent crowns and bridges attached to natural teeth and to implants, the second was treated by crowns attached to natural teeth and removable implant- supported prostheses. Depending on esthetic requirements and the localization of preparation margins all- or metal-ceramics were used for single crowns, metal-ceramics was used for bridges. In general, a well coordinated cooperation of dentist, surgeon and dental technician in treatment planning and realization is required for a successful prosthetic rehabilitation.

  16. Improved Prefrontal Activity and Chewing Performance as Function of Wearing Denture in Partially Edentulous Elderly Individuals: Functional Near-Infrared Spectroscopy Study

    PubMed Central

    Kamiya, Kazunobu; Narita, Noriyuki; Iwaki, Sunao

    2016-01-01

    The purpose of this study was to elucidate the effects of wearing a denture on prefrontal activity during chewing performance. We specifically examined that activity in 12 elderly edentulous subjects [63.1±6.1 years old (mean ± SD)] and 12 young healthy controls (22.1±2.3 years old) using functional near-infrared spectroscopy (fNIRS) in order to evaluate the quality of prefrontal functionality during chewing performance under the conditions of wearing a denture and tooth loss, and then compared the findings with those of young healthy controls. fNIRS and electromyography were used simultaneously to detect prefrontal and masticatory muscle activities during chewing, while occlusal force and masticatory score were also examined by use of a food intake questionnaire. A significant increase in prefrontal activity was observed during chewing while wearing a denture, which was accompanied by increased masticatory muscle activity, occlusal force, and masticatory score, as compared with the tooth loss condition. Prefrontal activation during chewing while wearing a denture in the elderly subjects was not much different from that in the young controls. In contrast, tooth loss in the elderly group resulted in marked prefrontal deactivation, accompanied by decreased masticatory muscle activity, occlusal force, and masticatory score, as compared with the young controls. We concluded that intrinsic prefrontal activation during chewing with a denture may prevent prefrontal depression induced by tooth loss in elderly edentulous patients. PMID:27362255

  17. Improved Prefrontal Activity and Chewing Performance as Function of Wearing Denture in Partially Edentulous Elderly Individuals: Functional Near-Infrared Spectroscopy Study.

    PubMed

    Kamiya, Kazunobu; Narita, Noriyuki; Iwaki, Sunao

    2016-01-01

    The purpose of this study was to elucidate the effects of wearing a denture on prefrontal activity during chewing performance. We specifically examined that activity in 12 elderly edentulous subjects [63.1±6.1 years old (mean ± SD)] and 12 young healthy controls (22.1±2.3 years old) using functional near-infrared spectroscopy (fNIRS) in order to evaluate the quality of prefrontal functionality during chewing performance under the conditions of wearing a denture and tooth loss, and then compared the findings with those of young healthy controls. fNIRS and electromyography were used simultaneously to detect prefrontal and masticatory muscle activities during chewing, while occlusal force and masticatory score were also examined by use of a food intake questionnaire. A significant increase in prefrontal activity was observed during chewing while wearing a denture, which was accompanied by increased masticatory muscle activity, occlusal force, and masticatory score, as compared with the tooth loss condition. Prefrontal activation during chewing while wearing a denture in the elderly subjects was not much different from that in the young controls. In contrast, tooth loss in the elderly group resulted in marked prefrontal deactivation, accompanied by decreased masticatory muscle activity, occlusal force, and masticatory score, as compared with the young controls. We concluded that intrinsic prefrontal activation during chewing with a denture may prevent prefrontal depression induced by tooth loss in elderly edentulous patients. PMID:27362255

  18. [Removable dentures with implants for edentulous lower jaw].

    PubMed

    Oszlánszky, Judit; Kádár, László; Hermann, Péter; Schmidt, Péter; Gyulai-Gaál, Szabolcs

    2013-09-01

    Fabrication of a complete mandibular denture that offers patient comfort, function, and aesthetics along with stability and acceptable retention remains one of the most challenging procedures in dental practice. Based on a thorough treatment planning and a successful surgical procedure implants have been shown to be reliable abutment for both retention and support of overdentures. During planning important relevant factors must be considered such as old age, systemic diseases, increased financial capability, etc. Implants retained overdentures can be divided into three groups according to the type of support: mucosal, muco-implantal and implantal. Key factors concerning the planning of prosthetic rehabilitation are the number and length of the implants, together with the quality and quantity of the anchoring bone tissue.

  19. Periodontal aspects of osseointegrated fixtures supporting a partial bridge. An up to 6-years retrospective study.

    PubMed

    Quirynen, M; Naert, I; van Steenberghe, D; Dekeyser, C; Callens, A

    1992-02-01

    The present paper reports on the use of osseointegrated titanium fixtures (Brånemark) in partially edentulous patients. The tissue reactions around 509 implants in 97 upper and 71 lower jaws of 146 consecutive patients, rehabilitated by means of partial bridges--supported by implants only (60%) or by the combination of teeth and implants (40%)--were observed longitudinally. The mean number of implants per bridge was 2.40 (range 1-5) for the upper jaw and 2.06 (range 1-5) for the lower jaw respectively. Before loading, a total of 23 fixtures were lost, 15 in the upper and 8 in the lower jaw. This loss could partially be correlated to per- and post-operative complications and to fixture characteristics (length, self-tapping or not). After a loading time of 30 months (range 2 to 77 months), 6 implants, 2 in the upper and 4 in the lower jaw, showed symptoms of non-integration. The cumulative failure rate for the individual fixtures after a 6-year period reached 5.7 and 6.5% for the upper and lower jaw, respectively. The mean annual marginal bone loss, scored on standardized radiographs, was 0.9 mm during the 1st year and 0.1 mm the following years. This loss in marginal bone height was equal in the upper and lower jaws and not related to the type of occlusal material of the bridges. The present data showed that the cumulative failure rate for Brånemark implants supporting partial bridges can be limited to 6% after a 6-year period, and that the radiographic bone loss is comparable with that found around fixtures supporting full bridges.

  20. Solitary peripheral osteomas of the jaws

    PubMed Central

    de França, Talita Ribeiro Tenório; Gueiros, Luiz Alcino Monteiro; de Castro, Jurema Freire Lisboa; Catunda, Ivson; Leão, Jair Carneiro

    2012-01-01

    Osteoma is a benign osteogenic tumor composed of cancellous or compact bone, classified as peripheral, central, or extraskeletal. Peripheral osteomas are uncommon. Excluding the maxillary sinuses, the maxilla is a rare site for osteomas. The purpose of this report was to describe clinicopathological and radiological features of two peripheral osteomas occurring in the jaws, one located in the mandible and another in the edentulous maxillary alveolar ridge. The tumors were asymptomatic and were fully excised without any complications or recurrence. The lesions were submitted to histopathological analysis and diagnosed as peripheral osteoma, compact type. PMID:22783479

  1. Jaw Injuries and Disorders

    MedlinePlus

    ... chin. The joint where the mandible meets your skull is the temporomandibular joint. Jaw problems include Fractures Dislocations Temporomandibular joint dysfunction Osteonecrosis, which happens when your bones lose their blood supply Cancers Treatment of jaw problems depends on the cause.

  2. Corrective Jaw Surgery

    MedlinePlus

    ... and Craniofacial Surgery Cleft Lip/Palate and Craniofacial Surgery A cleft lip may require one or more ... find out more. Corrective Jaw Surgery Corrective Jaw Surgery Orthognathic surgery is performed to correct the misalignment ...

  3. [Jaws of primitive mammals].

    PubMed

    Tsubamoto, Takehisa

    2005-06-01

    Some of main osteological differences between mammals and reptiles are seen in the number of bones that constitute lower jaw and in jaw articulation. A lower jaw of mammals consists of only one bone, while in reptiles it consists of several bones (e.g., four to six in lizards and five in crocodiles). The jaw articulation in mammals is performed by squamosal of the skull and the mandible ( = dentary), while in reptiles it is done by quadrate of the skull and articular of the lower jaw. When mammals first appeared about 200 million years ago in the Mesozoic Era, the jaws of primitive mammals were morphologically intermediate between those of reptiles and typical mammals. Here, I briefly introduce the evolution of lower jaw morphology from the reptilian one to the mammalian one, showing lower jaw features of some mammal-like reptiles and primitive mammals.

  4. Jaw and Order

    ERIC Educational Resources Information Center

    Mooshammer, Christine; Hoole, Philip; Geumann, Anja

    2007-01-01

    It is well-accepted that the jaw plays an active role in influencing vowel height. The general aim of the current study is to further investigate the extent to which the jaw is active in producing consonantal distinctions, with specific focus on coronal consonants. Therefore, tongue tip and jaw positions are compared for the German coronal…

  5. Maxillary overlay removable partial dentures for the restoration of worn teeth.

    PubMed

    Fonseca, Júlio; Nicolau, Pedro; Daher, Tony

    2011-04-01

    Prolonged tooth maintenance by a more aged population considerably increases the probability of dentists having to treat patients with high levels of tooth wear. Pathological tooth wear, caused primarily by parafunction, seems to be a growing problem that affects a large number of adult patients. The clinical report presents a case of a partially edentulous patient with an elevated degree of wear in the upper jaw caused by attrition and erosion, rehabilitated with a maxillary overlay removable partial denture (ORPD) consisting of a chrome-cobalt (Cr-Co) framework with anterior acrylic resin veneers, posterior cast overlays, and acrylic resin denture bases. Removable partial prosthesis is a treatment alternative when teeth are found to be severely worn or when the patient needs a simple and economical option. Because economics is a conditional factor of the treatment, the clinician should present different treatment alternatives to the patient, in which the overlay prosthesis can be considered.

  6. Maxillary overlay removable partial dentures for the restoration of worn teeth.

    PubMed

    Fonseca, Júlio; Nicolau, Pedro; Daher, Tony

    2011-04-01

    Prolonged tooth maintenance by a more aged population considerably increases the probability of dentists having to treat patients with high levels of tooth wear. Pathological tooth wear, caused primarily by parafunction, seems to be a growing problem that affects a large number of adult patients. The clinical report presents a case of a partially edentulous patient with an elevated degree of wear in the upper jaw caused by attrition and erosion, rehabilitated with a maxillary overlay removable partial denture (ORPD) consisting of a chrome-cobalt (Cr-Co) framework with anterior acrylic resin veneers, posterior cast overlays, and acrylic resin denture bases. Removable partial prosthesis is a treatment alternative when teeth are found to be severely worn or when the patient needs a simple and economical option. Because economics is a conditional factor of the treatment, the clinician should present different treatment alternatives to the patient, in which the overlay prosthesis can be considered. PMID:21560739

  7. Immediate Loading of Dental Implants Inserted in Edentulous Maxillas and Mandibles: 5-Year Results of a Clinical Study.

    PubMed

    Shigehara, Satoshi; Ohba, Seigo; Nakashima, Ken; Takanashi, Yoshiaki; Asahina, Izumi

    2015-12-01

    The aim of the present study was to evaluate the long-term outcome of immediately loaded full-arch, fixed, one-piece prostheses supported by dental implants inserted in completely edentulous maxillae and mandibles. Twenty-eight completely edentulous jaws in 27 patients were treated with screw-fixed provisional prostheses on the same day as implant insertion. A total of 189 implants were inserted into the jaws of the patients. All provisional prostheses were the one-piece bridge type and were made with acrylic resin. Final restoration was performed more than 2 months after surgery. Implant survival rate, prosthesis success rate, and complications during the follow-up period were evaluated. Implant size (diameter and length) and bone quality (Hounsfield units) of the region of the implant were also analyzed. Mean follow-up time was 77.9 months. The cumulative survival rate of the implants was 100%, and the success rate of the prostheses was also 100% during the observation time. Although 3 types of minor complications occurred in 10 jaws (10/28; 35.7%), no major complications were found. Immediate loading of dental implants produces an equivalent outcome as that reported in previous studies using conventional loading. We believe this study not only adds to the immediate loading data but also confirms that the immediate loading technique may be most advantageous strategy for edentulous patients. PMID:24707886

  8. Biological Width around One- and Two-Piece Implants Retrieved from Human Jaws

    PubMed Central

    Judgar, Ricardo; Zenobio, Elton; Coelho, Paulo G.; Feres, Magda; Rodrigues, Jose A.; Mangano, Carlo; Iezzi, Giovanna; Piattelli, Adriano; Shibli, Jamil Awad

    2014-01-01

    Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (P < 0.05). This difference was influenced by the connective tissue attachment, while sulcus depth and epithelial junction presented the same dimension for both groups (P > 0.05). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants. PMID:25050375

  9. Biological width around one- and two-piece implants retrieved from human jaws.

    PubMed

    Judgar, Ricardo; Giro, Gabriela; Zenobio, Elton; Coelho, Paulo G; Feres, Magda; Rodrigues, Jose A; Mangano, Carlo; Iezzi, Giovanna; Piattelli, Adriano; Shibli, Jamil Awad

    2014-01-01

    Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (P < 0.05). This difference was influenced by the connective tissue attachment, while sulcus depth and epithelial junction presented the same dimension for both groups (P > 0.05). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

  10. Complete Edentulism and Comorbid Diseases: An Update.

    PubMed

    Felton, David A

    2016-01-01

    The relationship between complete edentulism, which is the terminal outcome of a multifactorial oral disease process and other comorbid diseases, was first reported in 2009. Although the relationship between edentulism and a multitude of systemic diseases was reported, none of the publications studied could determine causality of tooth loss on the incidence of any comorbid disease. Since that publication, there has been a renewed interest in this relationship, and a plethora of new articles have been published. This article will provide an update on articles published since 2008 on the relationship between edentulism and comorbid diseases, and will include the relationship between complete edentulism and such comorbid conditions as malnutrition, obesity, cardiovascular disease, rheumatoid arthritis, pulmonary diseases (including chronic obstructive pulmonary disease), cancer, and even mortality.

  11. Dental implants in edentulous adults with cognitive disabilities: report of a pilot project.

    PubMed

    Durham, Timothy M; King, Thomas; Salinas, Thomas; Franco, Theodore; Ross, Jason

    2006-01-01

    Individuals with cognitive disabilities face many barriers to oral care, often suffering from partial or complete edentulism. While the use of implant reconstruction is becoming more common in the general population, such care is still being used infrequently in individuals with intellectual impairment. A pilot project in 1995 surgically placed and restored implant-supported prostheses in six edentulous adults who had varying degrees of cognitive impairment. This report presents the dentists' reconstruction experiences and the patients' follow-up care, and discusses the results in relationship to current literature. Experiences from these patients suggest that behavior during the restorative process, prosthetic complications post placement, and patients' oral hygiene practices should influence patient selection and prosthetic design. Anteriorly placed fixtures and removable designs, which make self-care and repair easier, can be used to treat an edentulous population. PMID:16703934

  12. Digital Cephalometric Tracings by PRO-CEPH V3 Software for Comparative Analyses of Vertical Dimension in Edentulous Patients

    PubMed Central

    Chittaranjan, B.; Kumar, B. Arun; Taruna, M.; Kumar, M. Pavan; Reddy, M. Ramu

    2015-01-01

    Background Several methods, some physiological, some radiographical and some merely based on experience are taken upon by the practitioner to get him/her close to VDO in the edentulous patients. No single method can however claim to be the perfect answer. Lateral cephalograms have been a standard mode of determining the vertical dimensions in dentate and edentulous patients since the past. Due to unavoidable manual errors, there are chances of variations in the radiographic method too. Advancement in the digital technology has made recording jaw relations faster, simpler and more precise. Aim This study compared the vertical dimension of occlusion in edentulous patients recorded by using three different physiological methods with the aid of digital cephalometric tracings using indigenously developed PRO-CEPH V3 software. Materials and Methods For the present study a total of 50 dentulous and 25 edentulous patients were selected through inclusion and exclusion criteria. A lateral cephalometric radiograph was taken for all the 50 dentulous subjects at Maximum Intercuspation (VDO) whereas three lateral cephalometric radiographs were obtained for all edentulous patients at the VDO following three different techniques- the Niswonger’s method, Phonetics method and Swallowing threshold method. Cephalometric tracings were carried out using indigenously developed PRO-CEPH V3 software. Linear and angular measurement were made and analysed. Conclusion The indigenously developed software PRO-CEPH V3 is capable of making both the linear and angular measurement and therefore provide with relative credibility information regarding the possible VDO in the edentulous patients through cephalometric radiography. PMID:26155550

  13. Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays.

    PubMed

    Chen, Hu; Yang, Xu; Chen, Litong; Wang, Yong; Sun, Yuchun

    2016-01-14

    The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3D FDM printing device. Another ten hand-made custom trays were produced as control. The 3-dimentional surface data of models and custom trays was scanned to evaluate the accuracy of reserved impression space, while the difference between digitally made trays and hand-made trays were analyzed. The digitally made custom trays achieved a good matching with the mandibular model, showing higher accuracy than the hand-made ones. There was no significant difference of the reserved space between different models and its matched digitally made trays. With 3D scanning, CAD and FDM technology, an efficient method of custom tray production was established, which achieved a high reproducibility and accuracy.

  14. Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays

    PubMed Central

    Chen, Hu; Yang, Xu; Chen, Litong; Wang, Yong; Sun, Yuchun

    2016-01-01

    The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3D FDM printing device. Another ten hand-made custom trays were produced as control. The 3-dimentional surface data of models and custom trays was scanned to evaluate the accuracy of reserved impression space, while the difference between digitally made trays and hand-made trays were analyzed. The digitally made custom trays achieved a good matching with the mandibular model, showing higher accuracy than the hand-made ones. There was no significant difference of the reserved space between different models and its matched digitally made trays. With 3D scanning, CAD and FDM technology, an efficient method of custom tray production was established, which achieved a high reproducibility and accuracy. PMID:26763620

  15. Biochemical and mechanical characterization of Nereis worm jaws

    NASA Astrophysics Data System (ADS)

    Broomell, Christopher C.

    The ultimate goal of biomimetics is to elucidate the design principles governing performance in biological materials and apply them to engineering systems. Successful transfer of these principles will require a thorough understanding of the complex interplay between molecular composition, organization and mechanical properties of the material. This dissertation describes the mechanical and biochemical characterization of jaws from the marine polychaete Nereis virens. Nereid jaws possess remarkable mechanical properties considering their predominantly organic composition. Hardness and stiffness are comparable to human dentin. However, in stark contrast to dentin, in Nereis these properties are achieved without mineralization. The role of metal ions in jaw sclerotization is addressed. In the pristine state, Zn ions are concentrated at the tip and toothed-edge of the jaw and are critical for hardness and modulus; both properties are reduced by ˜70% following Zn removal by treatment with EDTA. Furthermore, metal content in the jaw can be manipulated by soaking Zn-depleted samples in metal solutions; the comparative effects of treatment with alternative transition metals under both dry and hydrated conditions are described. The molecular composition of the jaw is also addressed. Protein comprises ˜90% of the jaw mass; amino acid analysis indicates that histidine is increased in the hardened, Zn-rich tip. The major protein component in Nereid jaw extracts is purified and characterized by partial peptide mapping and isolation of a partial clone from a jaw pulp cDNA library. Nvjp-1 is a 38 kDa glycine- histidine-rich protein and is believed to be the principle structural protein in the hardened jaw tip. The effects of selected environmental factors on Nvjp-1 structure and assembly are described. Transition from low to high pH is accompanied by changes in secondary structure and a significant molecular elongation. Furthermore, exposure to transition metals, notably Zn and

  16. Nonodontogenic Tumors of the Jaws.

    PubMed

    Dyalram, Donita; Aslam-Pervez, Nawaf; Lubek, Joshua E

    2016-02-01

    Nonodontogenic tumors of the jaws are common in the pediatric population, accounting for approximately 70% of pediatric jaw tumors. This article focuses on the clinical characteristics and management of the benign nonodontogenic tumors (nonaggressive and aggressive) of the jaws most commonly encountered in children.

  17. Radiographic apparatus for photographing entire jaws

    SciTech Connect

    Nakano, K.

    1985-01-22

    This disclosure relates to a dental radiographic apparatus for photographing the entire jaw designed to control the rotation of a rotary arm such that the film surface of a film holder mounted at one end of the rotary arm may rotate and move substantially at equal speed substantially equidistantly along the dental arch and that the X-ray beams irradiated upon the film surface from an X-ray generator mounted at the other end of the arm may fall on the dental arch at any point thereof at right angles with the arch. The apparatus makes it possible to obtain a very clear tomographic picture of a curved plane of the entire jaws, the picture being free of a double image of the teeth, partial change in enlargement ratio of the image obtained, and partial difference in the shade of the image obtained.

  18. Immediate loading of implants in the edentulous maxilla.

    PubMed

    Bergkvist, Göran

    2008-01-01

    the bone-implant interface during healing by adverse loading on the implants, which pierced the mucosa. Moreover, splinting the implants immediately after surgery with an interim fixed prosthesis might protect them from adverse loading. In a finite element analysis comparing uncoupled and splinted implants--imitations of the clinical situations in the two studies--splinted implants drastically reduced stresses in the bone tissue surrounding the implant, which might facilitate bone healing. Two factors considered important for a successful treatment outcome, especially when loading implants immediately, are (i) jawbone quality and (ii) primary implant stability at placement. In implant literature, bone quality is generally equivalent to bone density. Results of the third clinical study in this thesis indicate that use of computed tomography with calculations of bone mineral density can be a useful tool in bone tissue evaluation before implant placement. After 1 year of loading, changes in marginal bone level, compared to baseline, did not differ between implants that were stable and implants that were not stable at placement. The results of this thesis do not strengthen earlier recommendations that immediate and early loading is a treatment alternative that can be considered only in jaws with good bone quality. In conclusion, immediate loading with interim fixed prostheses in the edentulous maxilla is a viable treatment alternative. Splinting of implants seems to be important in immediate loading, especially when bone density is low. PMID:18637314

  19. Three-dimensional positional changes of teeth adjacent to posterior edentulous spaces in relation to age at time of tooth loss and elapsed time.

    PubMed

    Petridis, Haralampos P; Tsiggos, Nikolaos; Michail, Achilleas; Kafantaris, Sotirios N; Hatzikyriakos, Andreas; Kafantaris, Nikolaos M

    2010-06-01

    The purpose of this study was to study the stability of teeth adjacent to posterior edentulous spaces and correlate it with patient age and time lapse since tooth loss. Dental casts, panoramic radiographs, and questionnaires of patients treated in a University setting were employed. Teeth adjacent and opposing posterior edentulous spaces were examined for the following parameters: Supraeruption, rotation, space closure, and axial inclination. One hundred twenty three patients with 229 edentulous spaces were analyzed. Statistical analysis showed that the effects of "jaw", "gender", and "age group at the time of tooth loss" were not significant for any of the variables tested. The effect of time lapse since tooth loss was significant regarding the "amount of distal tooth inclination" (P<0.001), the "amount of distal tooth rotation" (P=0.004), and "space closure" (P=0.038). Post-hoc analysis of the "amount of distal tooth inclination" revealed a marked increase in inclination 5 years after tooth loss. Within the limitations of this study, it was concluded that in the group of patients studied, minor positional changes in teeth opposing or adjacent to posterior edentulous spaces had occurred. The greatest changes in position were recorded for mandibular teeth distal to edentulous spaces.

  20. Projections of U.S. Edentulism Prevalence Following 5 Decades of Decline

    PubMed Central

    Slade, G.D.; Akinkugbe, A.A.; Sanders, A.E.

    2014-01-01

    After decades of decline in prevalence of complete tooth loss (edentulism), the trend continues to be misinterpreted, producing flawed projections and misdirected health goals. We investigated population trends in edentulism among U.S. adults aged ≥15 yr by creating time-series data from 5 national cross-sectional health surveys: 1957-1958 (n ≈ 100,000 adults), 1971-1975 (n = 14,655 adults), 1988-1998 (n = 18,011 adults), 1999-2002 (n = 12,336 adults), and 2009-2012 (n = 10,522 adults). Birth cohort analysis was used to isolate age and cohort effects. Geographic and sociodemographic variation in prevalence was investigated with a sixth U.S. survey of 432,519 adults conducted in 2010. Prevalence through 2050 was projected with age-cohort regression models using Monte-Carlo simulation of prediction intervals. Across the 5-decade observation period, edentulism prevalence declined from 18.9% in 1957-1958 (95% confidence limits: 18.4%, 19.4%) to 4.9% in 2009-2012 (95% confidence limits: 4.0%, 5.8%). The most influential determinant of the decline was the passing of generations born before the 1940s, whose rate of edentulism incidence (5%-6% per decade of age) far exceeded later cohorts (1%-3% per decade of age). High-income households experienced a greater relative decline, although a smaller absolute decline, than low-income households. By 2010, edentulism was a rare condition in high-income households, and it had contracted geographically to states with disproportionately high poverty. With the passing of generations born in the mid-20th century, the rate of decline in edentulism is projected to slow, reaching 2.6% (95% prediction limits: 2.1%, 3.1%) by 2050. The continuing decline will be offset only partially by population growth and population aging such that the predicted number of edentulous people in 2050 (8.6 million; 95% prediction limits: 6.8 million, 10.3 million) will be 30% lower than the 12.2 million edentulous people in 2010. PMID:25146182

  1. Follicular jaw cysts.

    PubMed

    Sarac, Zdenko; Perić, Berislav; Filipović-Zore, Irina; Cabov, Tomislav; Biocić, Josip

    2010-03-01

    The aim of this study was to examine the occurrence, localization, size, ways of diagnosing and treatment of a foIlicular jaw cyst. Assessment of the patients' motives and their earlier health status was recorded, as well as their postoperative clinical course. Most of the patients were admitted because of pain, swelling, trismus, or other difficulties associated with cyst formation. Follicular cysts with persisting primary predecessor had an asymptomatic development, and were discovered after orthodontic examination or by chance. In most cases pathohistological finding and description of the formation have coincided with each other (p < 0.05). Cysts of different sizes were treated by different surgical approaches, most commonly alveolotomy and cystectomy in small cysts, while alveolotomy and cystectomy with suction or iodine tampon in large cysts. Cooperation of a dentist, an oral surgeon, a pathologist, and other specialists can lead to early diagnose and prevention of further growth of a follicular jaw cyst, thus preventing substantial bone damage.

  2. [Jaws of birds].

    PubMed

    Matsuoka, Hiroshige

    2005-05-01

    Birds (Class Aves) have been hypothesized to have evolved from theropod dinosaurs, which belong to the group known as diapsid reptiles, during the Mesozoic era. They subsequently acquired derived characters relating to flying ability in all parts of their body, including the jaws, which were toothed in the ancestral forms but beaked in later members. When the fore limbs became modified as wings specialized for flight, they became incapable of grasping food, which function was then assumed by the avian bill. Avian bills consequently evolved great morphological diversity reflecting very divergent modes of feeding. To illustrate the progression of "the evolution of vertebrate jaws," the comparative osteology of avian cranial bones is exemplified by reference to Mesozoic birds and the morphological and functional variations observed among the bills of Neornithes.

  3. Dentulous appliance for upper anterior edentulous span.

    PubMed

    Chalakkal, Paul; Devi, Ramisetty Sabitha; Srinivas, G Vijay; Venkataramana, Pammi

    2013-12-01

    This article discusses about a fixed dentulous appliance that was constructed to replace the primary upper anterior edentulous span in a four year old girl. It constituted a design, whereby the maxillary primary second molars were used to support the appliance through bands and a wire that contained an acrylic flange bearing trimmed acrylic teeth, anteriorly. The appliance was functionally and aesthetically compliant.

  4. A population-based study of edentulism in the US: does depression and rural residency matter after controlling for potential confounders?

    PubMed Central

    2014-01-01

    Background Oral health is an integral component of general health and well-being. While edentulism has been examined in relation to socioeconomic status, rural residency, chronic disease and mental health, no study that we know of has examined edentulism and these factors together. The objective of this study was to determine whether depression and rural residency were significantly associated with partial and full edentulism in US adults after controlling for potential confounders. Methods 2006 Behavioral Risk Factor Surveillance Survey (BRFSS) data were analyzed to identify factors associated with increased odds of partial or full edentulism. This year of BRFSS data was chosen for analysis because in this year the standardized and validated Personal Health Questionnaire-8 (PHQ-8) was used to measure current depression. This measure was part of the optional questions BRFSS asks, and in 2006 33 states and/or territories included them in their annual surveillance data collection. Bivariate and logistic regression analyses were performed on weighted BRFSS data. Results Logistic regression analysis using either full or partial edentulism as the dependent variable yielded that rural residency or living in a rural locale, low and/or middle socioeconomic status (SES), depression as measured by the PHQ-8, and African American race/ethnicity were all independent risk factors when controlling for these and a number of additional covariates. Conclusions This study adds to the epidemiological literature by assessing partial and full edentulism in the US utilizing data from the CDC’s Behavioral Risk Factor Surveillance System (BRFSS). Examining data collected through a large national surveillance system such as BRFSS allows for an analysis that incorporates an array of covariates not available from clinically-based data alone. This study demonstrated that current depression and rural residency are important factors related to partial and full edentulism after controlling for

  5. Rehabilitation of an edentulous mandible with an implant-supported prosthesis.

    PubMed

    LoCascio, S J; Salinas, T J

    1997-04-01

    The advances in osseointegration have resulted in an increased utilization of implants for restoration of the edentulous jaw. The success of osseointegrated implants supporting full arch prostheses has become more predictable. All implant restorations require a thorough diagnosis and a definitive treatment plan. Following a diagnostic wax-up, an optimal surgical implant template must be fabricated; it serves as a guide or prescription for placement of implants in an optimal anatomic location. The slightest misangulation of an implant may create restorative limitations. In such circumstances, alteration of the restorative design or selection of alternate materials may be required. The learning objective of this article is to review the fabrication of a combined ceramometal and resin-metal fixed/removable implant-supported mandibular hybrid prosthesis. Diagnosis, surgical template fabrication, vertical dimensions, buccal/lingual space limitations, and aesthetics are discussed.

  6. Dentulous Appliance for Upper Anterior Edentulous Span

    PubMed Central

    Chalakkal, Paul; Devi, Ramisetty Sabitha; Srinivas, G. Vijay; Venkataramana, Pammi

    2013-01-01

    This article discusses about a fixed dentulous appliance that was constructed to replace the primary upper anterior edentulous span in a four year old girl. It constituted a design, whereby the maxillary primary second molars were used to support the appliance through bands and a wire that contained an acrylic flange bearing trimmed acrylic teeth, anteriorly. The appliance was functionally and aesthetically compliant. PMID:24551736

  7. Morphology of Thai Edentulous Mandible Using 3D Reverse Engineering: Relevance to Immediate Loading Dental Implant Design

    NASA Astrophysics Data System (ADS)

    Kasemsarn, Suthasinee; Mahaisavariya, Banchong; Sitthiseripratip, Kriskrai; Suwanprateeb, Jintamai

    The dimension and number of implants as well as the splinting concept of the superstructure are the impact factors of the immediate loading implant-supported prostheses. The purpose of this study is to determine the morphometric data of Thai lower edentulous jaws between two metal foramens for optimizing the design. Sixty-four Thai cadaveric edentulous mandibles were CT scanned and 3D models were reconstructed. Arch forms, dimensions, and the area of the greatest concavity in the body of the mandibles between the metal foramens were defined in geometric terms based on reverse engineering methods. The arch forms, represented by average values of angle and distance of panoramic arc, were 116.4 ±9.5 degrees and 46.7 ±3.9mm respectively. The dimensions of the mandibles, determined by the height and width of the body of the mandibles as well as the angle between the axis of the mandibular body to the mandibular plane, were 25.3 ±0.6mm, 11.6 ±0.6mm and 61.3 ±1.7 degrees respectively. The area of greatest concavity was 8.3 ±1.9mm. Morphology of the Thai edentulous mandible determines the maximum length of an implant placed for immediate loading protocol as 17mm, with a maximum diameter of 3.5-5mm. The maximum number of implants that can be placed in the anterior region is 5.

  8. Using acrylic resin tooth veneers in patients with an abnormal jaw relationship: a case report.

    PubMed

    Yang, Tsung-Chieh; Lan, Yi-Hao; Wang, Tong-Mei; Tu, Ching-Yu; Lin, Li-Deh

    2014-01-01

    This case report describes and evaluates a method of arranging artificial teeth in patients with an abnormal jaw relationship in which a wider maxillary arch opposes a narrower mandibular arch. First, the fossa of mandibular posterior teeth was positioned on the crest of the mandibular edentulous ridge. The maxillary posterior teeth were then placed palatally to maximize occlusal contacts with the opposing mandibular teeth. Finally, acrylic resin tooth veneers were attached on the buccal surface of posterior maxillary teeth to improve the arch discrepancy. This method addresses functional considerations with the inner aspect of teeth and esthetic considerations with acrylic resin tooth veneers.

  9. Aesthetic provisional restoration for the partially edentulous, immediate, postimplantation patient.

    PubMed

    McCord, J F; Smith, G A; Quayle, A A

    1992-01-01

    This article reviews the methods currently used for making provisional restorations for endosseous dental implants. With the requirements for osseointegration in mind, a simple and aesthetic alternative is suggested. The clinical and laboratory stages for the fabrication of the prosthesis are outlined.

  10. Human jaw and muscle modelling.

    PubMed

    Peck, Christopher C; Hannam, Alan G

    2007-04-01

    Dynamic mathematical modelling is an invaluable method to help understand the biomechanics of the anatomically and functionally complex masticatory system. It provides insight into variables which are impossible to measure directly such as joint loads and individual muscle tensions, and into physical relationships between jaw structure and function. Individual parameters can be modified easily to understand their influence on function. Our models are constructed with best available structural and functional data, and evaluated against human jaw behaviour. Image data provide hard and soft tissue morphology and the jaw's inertial properties. The drive to the system is provided by actuators which simulate active and passive jaw muscle properties. In whole-jaw modelling, muscle models which behave plausibly rather than mimic the ultra-structural cross-bridge interactions are common since they are computationally feasible. Whole-jaw models have recently incorporated flexible finite-elements to explore tissue distortion in the temporomandibular joint and tongue movements. Furthermore, the jaw has been integrated with laryngeal models to explore complex tasks such as swallowing. These dynamic models have helped better understand joint loading, movement constraints and muscle activation strategies. Future directions will include further incorporation of rigid and flexible model dynamics and the creation of subject-specific models to better understand the functional implications of pathology.

  11. Management of the edentulous/atrophic mandibular fracture.

    PubMed

    Aziz, Shahid R; Najjar, Talib

    2009-03-01

    Edentulous or atrophic mandible fractures are rare and potentially problematic for the oral and maxillofacial surgeon. With the loss of teeth, atrophy of the alveolar bony apparatus ensues, creating a mandible more prone to fracture. This article describes the management of edentulous/atrophic mandibular fractures.

  12. Overdentures on Implants for Better Quality of Life Among the Fully Edentulous Patients - Case Reports.

    PubMed

    Nikolovska, Julijana; Petrovski, Dragan; Petricevic, Nikola; Kapusevska, Biljana; Korunoska-Stevkovska, Vesna

    2015-01-01

    Global aging population has brought several challenges for their medical systems and total edentulism is one of them. The fabrication of removable acrylic dentures seems to be a simple and cheap treatment solution, but a majority of patients is not satisfied with their functional instability, causing limited diets, mouth soreness, speech and psycho-social problems etc. The results in many studies indicate an impact of oral conditions associated with the full denture wearing on oral-health related quality of life, especially in lower jaw. The reason for improper denture retention could be alveolar ridge bone resorption and numerous studies about this problem are plausible. Bone resorption in lower jaw may turn the alveolar ridge into a flabby soft tissue which is unable to sustain proper denture retention. The implant-retained prosthesis is an alternative treatment option in these situations. Implants will provide retention, stability, function and aesthetics and they are not so expensive solution. The aim of this article is to show solving of retention problems of a lower denture in two different clinical cases using implants and without any special technology. PMID:27442389

  13. [Osseous tumors of the jaw].

    PubMed

    Reychler, H

    1988-01-01

    The osseous tumors of the jaw bones are relatively rare but very oft malignant. This work analyses the different epidemiological, clinical, radiological, histological and therapeutic features of the benign and malignant osseous tumors of the jaw bones, with regard to the most recent literature. The described benign tumors are the osteoma and osteomatosis, the osteoblastoma and osteoid osteoma, the desmo-osteoblastoma and the exostosis. The osteosarcoma is the unique malignant osseous tumor encountered.

  14. Pediatric jaw tumors: Our experience

    PubMed Central

    Saxena, Susmita; Kumar, Sanjeev; Pundir, Siddharth

    2012-01-01

    Background: Reports of series of central jaw tumours in children are rare hence predicting their biological behaviour as well as treatment, prognosis have not been documented from this part of the world. Aim: To study retrospectively, the paediatric central jaw tumours, reported to our institute with relation to site of occurrence, presentation and biological behaviour. Materials and Methods: All consecutive patients (<18 years), between 2004-2010, histologically diagnosed as having an intraosseous tumour or tumour-like lesions formed the study population. Patients fulfilling the inclusion criteria were only considered for further study. The entire study material was analyzed and grouped into various categories for logical conclusions. The data accumulated were grouped, entered and analyzed. Results: Sixty-one cases fulfilled the criteria. Gender distribution was equal, with mandible predominance (2.2:1) and a predominance of non-odontogenic lesions (2:1). There were 4 malignant and 57 benign conditions. Anterior jaw lesions were 23 while 38 were present in the posterior region of jaws (1:1:6). Conclusions: The pattern of central jaw tumours presentation in children from this part of India has been documented. In this study, paediatric jaw tumours are less common compared to those in adults with non-odontogenic tumours being common. The finding of the present study indicates that an impacted tooth, beyond the eruption time deserves more attention for the reason of associated pathologies in children. PMID:22438639

  15. Radiological findings in edentulous Kenyan patients.

    PubMed

    Kaimenyi, J T; Karongo, P; Ocholla, T J

    1993-03-01

    Seven hundred and seventy five files of edentulous patients seen at the Department of Dental Surgery, University of Nairobi were scrutinized for the presence or absence of routine radiographs prior to treatment. 180 (23.2%) had radiographs. 26% of the radiographs had 51 positive radiological findings. 17.3% were roots, 3.9% were unerupted teeth, 6.7% were radiopacities and 0.6% were radiolucencies. 52.9% of the radiological findings were in the mandible and 47.1% were in the maxilla. In the mandible, 44.4% of the radiological findings were in the anterior region and 55.6% were found posteriorly. 66.7% of the maxillary radiological findings were in the anterior region and 33.3% were found posteriorly. Since some of the positive radiological findings such as the retained roots and unerupted teeth might lead to infection, cysts or poor dentures fit, it is recommended that whenever possible, all edentulous patients be examined radiographically prior to treatment. PMID:8261948

  16. Impact of fixed implant supported prostheses in edentulous patients: protocol for a systematic review

    PubMed Central

    López, Carolina S; Saka, Constanza H; Rada, Gabriel; Valenzuela, Daniela D

    2016-01-01

    Introduction Edentulism is a debilitating and irreversible condition described as the ‘final marker of disease burden for oral health’. Therapy with dental implants is being used on a large scale to replace missing teeth and to rehabilitate edentulous patients with overdentures and implant supported fixed dentures as a method of solving the problem of instability and lack of retention associated with conventional removable prostheses. Fixed implant supported prostheses are an alternative for implant rehabilitation treatment that allow patients to have new fixed teeth. They can be indicated in partial or total edentulous patients, and they can replace single teeth, or teeth and supporting tissues (hybrid prosthesis). They overcome the limitations of conventional dentures, increasing stability and retention, providing functional and psychological advantages for the patients. Methods and analysis We will electronically search for randomised controlled trials evaluating the effects of fixed implant supported prostheses in edentulous patients in the following databases: Pubmed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. We will also try to obtain literature screening references of included studies, searching for trial protocols in the WHO International Clinical Trials Registry Platform, reviewing International Team for Implantology conference proceedings and searching for non-published studies through Open Gray. Two researchers will independently undertake selection of studies, data extraction and assessment of the quality of the included studies. Data synthesis and subgroup analyses will be performed using special Review Manager software. Data will be combined in a meta-analysis using a random effects model. Results The results will be presented as risk ratios for dichotomous data, and as mean difference or standardised mean difference for continuous data. Ethics and dissemination No ethics approval is considered necessary. The results

  17. Prosthetic procedure for simultaneous immediate loading of opposing edentulous arches.

    PubMed

    Biscaro, Leonello; Ferlin, Paolo; Becattelli, Alberto; Vigolo, Paolo

    2014-10-01

    For patients with complete edentulism, a significant problem is the transfer of diagnostic data to the definitive casts when an immediate loading technique is used. This article presents a prosthetic procedure to allow simultaneous treatment of opposing edentulous arches with immediate implant loading. This technique uses 2 occlusal acrylic resin devices to transfer the diagnostic cast information to the definitive casts. Esthetic and functional fixed dental prostheses are fabricated from diagnostic information acquired in the presurgical phase without any impression or recording of the maxillomandibular relationship during or after surgery. This methodology is applicable when the simultaneous immediate loading of implants in 2 edentulous arches is indicated.

  18. A selective-pressure impression technique for the edentulous maxilla.

    PubMed

    Duncan, Jacqueline P; Raghavendra, Sangeetha; Taylor, Thomas D

    2004-09-01

    This article describes a selective-pressure impression technique for the edentulous maxilla that is intended to compensate for the polymerization shrinkage of heat-polymerized polymethyl methacrylate resin and provides improved palatal adaptation of the definitive denture base.

  19. JAWS multiple Doppler derived winds

    NASA Technical Reports Server (NTRS)

    Elmore, Kimberly L.

    1987-01-01

    An elementary working knowledge is given of the advantages and limitations of the multiple Doppler radar analyses that have recently become available from the Joint Airport Weather Studies (JAWS) project. What Doppler radar is and what it does is addressed and the way Doppler radars were used in the JAWS project to gather wind shear data is described. The working definition of wind shear used is winds that affect aircraft flight over a span of 15 to 45 seconds and turbulence is defined as air motion that cause abrupt aircraft motions. The JAWS data current available contain no turbulence data. The concept of multiple Doppler analysis and the geometry of how it works are described, followed by an explanation of how data gathered in radar space are interpolated to a common Cartesian coordinate system and the limitations involved. A discussion is also presented of the analysis grid and how it was constructed. What the user actually gets is discussed, followed by a discussion of the expected errors in the three orthogonal wind components. Finally, a discussion is presented of why JAWS data are significant.

  20. [Rehabilitation by composite prosthesis combining milling of embedded bilateral edentulous: a clinical report].

    PubMed

    Janati, G; Cheikh, Y; Touwaye, S; Bellemkhannate, S

    2014-06-01

    The treatments with composite prosthesis require the completion of milling. These precision preparations in the fixed prosthesis promote the integration of removable partial denture with metallic framework in mechanical (prosthetic balance), physiological, aesthetical and psychological point of view. Their conception and realization are always subordinated to the balance principles of the removable partial denture. The precision they require need the use of a dental milling machine working along the predetermined insertion axis of the partial denture casting and require an excellent communication and a close collaboration between dentist and experienced technician of laboratory. In this paper, after a recalling about the milling (definition, description, interests), we will detail the steps to achieve clinical and laboratory needs for a rehabilitation by composite prosthesis combining milling, and it will be illustrated through a clinical case with a bilateral tooth-supported edentulous in the maxilla.

  1. Influence of edentulism on human orbit and zygomatic arch shape.

    PubMed

    Williams, Shanna E; Slice, Dennis E

    2014-04-01

    Edentulism, or tooth loss, seriously alters the appearance of the lower facial skeleton. The aim of this study was to determine if complete maxillary edentulism also impacts the curvature shape of the orbits and zygomatic arches in elderly adults. The study was conducted on 80 crania comprising two cross-sectional populations of elderly African- and European-Americans (60-80 years old). Forty of the crania possessed intact dentition; the remaining 40 exhibited complete edentulism with tooth socket resorption. Three-dimensional semilandmarks representing the curvature of the orbits and zygomatic arches were collected using a hand-held digitizer. Each craniofacial region's semilandmarks were aligned into a common coordinate system via generalized Procrustes superimposition. Regional variation in shape was explored via principal component analysis, multivariate analysis of variance, discriminant function analysis, cross-validation, and vector plots. Shape differences between the edentulous and dentate groups were detected in both the orbits (P = 0.0022) and zygomatic arches (P = 0.0026). Ancestry and sex differences were also identified in both regions. Orbit data correctly classified dentate crania 65% of the time and edentulous crania 72.5% of the time. Zygomatic arch data correctly classified 75% dentate and 60% of edentulous crania. The individual curves constituting each region also exhibited shape alteration with tooth loss, with the exception of the inferior zygomatic curve. Vector plots revealed patterns of superoinferior expansion, and medial and lateral recession depending on the region examined. These results suggest a relationship exists between maxillary edentulism and changes in the surrounding craniofacial structures.

  2. Reconstruction of severely resorbed edentulous maxillae using osseointegrated fixtures in immediate autogenous bone grafts.

    PubMed

    Adell, R; Lekholm, U; Gröndahl, K; Brånemark, P I; Lindström, J; Jacobsson, M

    1990-01-01

    A surgical technique for rehabilitation of severely resorbed edentulous maxillae using fixed prostheses or overdentures supported by osseointegrated fixtures in immediate autogenous corticocancellous bone grafts from the ilium is described. The results of the first 23 consecutively treated patients are reviewed. The mean observation time was 4.2 years (range 1 to 10 years). A total of 124 fixtures was originally placed into the grafts, supplemented with 16 fixtures inserted later into seven of the jaws. Throughout their observation period, 17 of the patients had continuously stable prostheses. The remaining five had overdentures, and one patient had resorted to a conventional complete denture. After 4 years, 12 of 16 patients had continuously stable prostheses. Corresponding values at 5 years were 7 of 8 patients. Calculated from the date of abutment connection, 82.1% and 81.6% of the original fixtures were clinically stable and radiographically osseointegrated after 4 and 5 years in function, respectively. From the date of fixture placement, the corresponding figures were 75.3% and 73.8%, respectively. The mean marginal bone loss after the first year of prosthesis function was 1.49 mm. The annual marginal bone loss thereafter was about 0.1 mm. The results indicate that this technique is worthwhile for patients with extreme maxillary atrophy and who cannot wear conventional complete dentures.

  3. Self-aligning lathe chuck jaws

    DOEpatents

    Peterson, William R.

    1982-01-01

    A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw in to and out from the workpiece. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-comforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.

  4. Self-aligning lathe chuck jaws

    DOEpatents

    Not Available

    1980-08-26

    A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw into and out from the workpiece is described. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-conforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.

  5. Edentulism, beaks, and biomechanical innovations in the evolution of theropod dinosaurs

    PubMed Central

    Lautenschlager, Stephan; Witmer, Lawrence M.; Altangerel, Perle; Rayfield, Emily J.

    2013-01-01

    Maniraptoriformes, the speciose group of derived theropod dinosaurs that ultimately gave rise to modern birds, display a diverse and remarkable suite of skeletal adaptations. Apart from the evolution of flight, a large-scale change in dietary behavior appears to have been one of the main triggers for specializations in the bauplan of these derived theropods. Among the different skeletal specializations, partial or even complete edentulism and the development of keratinous beaks form a recurring and persistent trend in from the evolution of derived nonavian dinosaurs. Therizinosauria is an enigmatic maniraptoriform clade, whose members display these and other osteological characters thought to be correlated with the shift from carnivory to herbivory. This makes therizinosaurians prime candidates to assess the functional significance of these morphological characters. Based on a highly detailed biomechanical model of Erlikosaurus andrewsi, a therizinosaurid from the Upper Cretaceous of Mongolia, different morphological configurations incorporating soft-tissue structures, such as a keratinous rhamphotheca, are evaluated for their biomechanical performance. Our results indicate that the development of beaks and the presence of a keratinous rhamphotheca would have helped to dissipate stress and strain, making the rostral part of the skull less susceptible to bending and displacement, and this benefit may extend to other vertebrate clades that possess rhamphothecae. Keratinous beaks, paralleled by edentulism, thus represent an evolutionary innovation developed early in derived theropods to enhance cranial stability, distinct to postulated mass-saving benefits associated with the origin of flight. PMID:24297877

  6. Edentulism, beaks, and biomechanical innovations in the evolution of theropod dinosaurs.

    PubMed

    Lautenschlager, Stephan; Witmer, Lawrence M; Altangerel, Perle; Rayfield, Emily J

    2013-12-17

    Maniraptoriformes, the speciose group of derived theropod dinosaurs that ultimately gave rise to modern birds, display a diverse and remarkable suite of skeletal adaptations. Apart from the evolution of flight, a large-scale change in dietary behavior appears to have been one of the main triggers for specializations in the bauplan of these derived theropods. Among the different skeletal specializations, partial or even complete edentulism and the development of keratinous beaks form a recurring and persistent trend in from the evolution of derived nonavian dinosaurs. Therizinosauria is an enigmatic maniraptoriform clade, whose members display these and other osteological characters thought to be correlated with the shift from carnivory to herbivory. This makes therizinosaurians prime candidates to assess the functional significance of these morphological characters. Based on a highly detailed biomechanical model of Erlikosaurus andrewsi, a therizinosaurid from the Upper Cretaceous of Mongolia, different morphological configurations incorporating soft-tissue structures, such as a keratinous rhamphotheca, are evaluated for their biomechanical performance. Our results indicate that the development of beaks and the presence of a keratinous rhamphotheca would have helped to dissipate stress and strain, making the rostral part of the skull less susceptible to bending and displacement, and this benefit may extend to other vertebrate clades that possess rhamphothecae. Keratinous beaks, paralleled by edentulism, thus represent an evolutionary innovation developed early in derived theropods to enhance cranial stability, distinct to postulated mass-saving benefits associated with the origin of flight.

  7. Presence of Serum Ferritin before and after Bariatric Surgery: Analysis in Dentate and Edentulous Patients

    PubMed Central

    Mosquim, Victor; Sales Peres, Matheus de Carvalho; Ceneviva, Reginaldo; Chaim, Elinton Adami

    2016-01-01

    Society has changed its own lifestyle, specially its eating habits and physical activities, leading to excessive weight and a sedentary behavior, which has contributed to obesity increase. Bariatric surgery is the most effective treatment to obesity, allowing weight loss and its maintenance. However, it has been related high levels of iron deficiency after surgery. A person’s nutritional status might be affected by total or partial tooth loss. The aim of this longitudinal prospective cohort study was to evaluate the levels of serum ferritin before and after bariatric surgery and to identify if there is a relation with tooth loss. The sample was composed of 50 patients selected and assisted at Amaral Carvalho Hospital, located in Jaú city, Brazil. The use and necessity of prosthesis, dental absence or presence, and serum ferritin dosage were evaluated. Student’s t test, Univariate analysis, Chi-square and Odds Ratio were adopted (p<0.05). There was no significant difference regarding the serum ferritin levels between dentate and edentulous patients prior to surgery (p = 0.436). After surgery, the serum ferritin levels were higher in edentulous patients (prosthesis users) when compared to the pre-surgical levels, and the post-surgical levels presented significant difference regarding the dentate patients (p = 0.024). It can be concluded that rehabilitated patients in postoperative period showed better levels of serum ferritin after surgical intervention. PMID:27695053

  8. [The tongue as a factor in craniofacial growth. 2. The influence of the width dimension of the lower jaw].

    PubMed

    Becker, R; Hübner, A; Pommerenke, F; Schumacher, G H

    1988-01-01

    The role played by the tongue in orofacial growth is also indicated by the reduced width of the lower jaw. In miniature pigs MINI-LEWE that were partially glossectomized at an age of 12 weeks lateral growth of the whole lower jaw was reduced after eight months. In animals that had been glossectomized at an age of six weeks lateral growth of the lower jaw was reduced in the region of the 1st deciduous molars and the canines right months after glossectomy.

  9. The development of jaw motion for mastication

    PubMed Central

    Wilson, Erin M.; Green, Jordan R.

    2009-01-01

    The developmental course of early chewing has rarely been studied, although such knowledge is essential for understanding childhood feeding and swallowing disorders. The goal of this investigation was to quantitatively describe age- and consistency-related changes in jaw kinematics during early chewing development. An optical-motion tracking system was used to record jaw movements during chewing in 3-dimensions in 11 typically-developing participants longitudinally from 9–30 months of age. Age related changes in jaw movement were described for both puree and regular consistencies. The findings demonstrated that the development of rotary jaw motion, jaw motion speed, and management of consistency upgrades are protracted across the first two years of life. Young children did not differentiate their jaw closing speeds for puree and regular consistencies until 18–24 months of age, at which age the speed of movement was significantly slower for the puree than for the regular consistency. Horizontal jaw closing speed decreased significantly with age for the puree consistency, but not for the regular consistency. The emergence of a rotary chew pattern was not observed at the ages studied. PMID:19185434

  10. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2060 Jaw tracking device. (a) Jaw tracking device... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Jaw tracking device. 872.2060 Section 872.2060... device for monitoring mandibular jaw positions relative to the maxilla is a nonpowered or...

  11. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2060 Jaw tracking device. (a) Jaw tracking device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Jaw tracking device. 872.2060 Section 872.2060... device for monitoring mandibular jaw positions relative to the maxilla is a nonpowered or...

  12. Single implant in the mandibular molar region of edentulous patient.

    PubMed

    Zhai, Jun-Jiang; Wen, Cai; Teng, Ming-Hua; Liang, Xing

    2013-09-01

    Implant-retained overdentures are a valid treatment option for edentulous patients, especially for patients with severe alveolar ridge atrophy. A central single implant is considered adequate to retain an overdenture in the edentulous mandible. However, for some patients, there is no sufficient bone height, or width in the interforaminal region of the mandible for insertion of the implant. This case report illustrates that the insertion of a single implant in the mandibular molar region might stabilize the prosthesis, and might improve the oral health-related quality of life and chewing function. A Locator attachment was used in this case to retain the overdenture. The one-year clinical results are promising. However, long-term clinical results and randomized clinical trials are needed before this method can be widely used in clinical application.

  13. Bone mineral density in periodontally healthy and edentulous postmenopausal women.

    PubMed

    Bando, K; Nitta, H; Matsubara, M; Ishikawa, I

    1998-07-01

    (Osteoporosis is the most common metabolic disease among postmenopausal women. Reduced masticatory function caused by tooth loss may be a contributing risk factor of osteoporosis. The present study examined the effect of dentate state on skeletal bone mineral density (BMD) in postmenopausal women. Fourteen periodontally healthy dentate subjects (group H; mean age: 64.0 + 5.5 years) and 12 edentulous subjects (group E; mean age: 67.1 + 2.9 years) were randomly selected from the clinics of the departments of Periodontology and Gerodontology, respectively. Informed consent was obtained from all participants. BMD of the lumbar spine (L2-L4) was measured by dual energy x-ray absorptiometry. In addition, occlusal force was measured in 11 group H subjects and 8 group E subjects by using an occlusal diagnostic system. Risk factors associated with osteoporosis including age, calcium intake, physical activity, and cigarette smoking and causes of tooth loss were assessed by interview and questionnaire sent to all participants. The BMD of group H was 1.07 t 0.21 g/cm2 and that of group E was 0.89 + 0.17 g/cm2, which was significantly different(P< 0.05). The occlusal force of group H and E patients was 312.4 + 148 Nand 56.3 + 36 N, respectively, which was significantly different (P< 0.05). Risk factors such as calcium intake, physical activity, and smoking did not differ significantly between the 2 groups. Thus, the periodontally healthy dentate women, who showed about 6 times higher occlusal force than edentulous women, maintained significantly higher BMD of the lumbar spine than edentulous women. Our results suggest that sufficient masticatory function with periodontally healthy dentition may inhibit or delay the progress of osteoporotic change in skeletal bone or that edentulous women may be more susceptible to osteoporosis.

  14. JAWS coordinates chondrogenesis and synovial joint positioning.

    PubMed

    Sohaskey, Michael L; Yu, Jane; Diaz, Michael A; Plaas, Anna H; Harland, Richard M

    2008-07-01

    Properly positioned synovial joints are crucial to coordinated skeletal movement. Despite their importance for skeletal development and function, the molecular mechanisms that underlie joint positioning are not well understood. We show that mice carrying an insertional mutation in a previously uncharacterized gene, which we have named Jaws (joints abnormal with splitting), die perinatally with striking skeletal defects, including ectopic interphalangeal joints. These ectopic joints develop along the longitudinal axis and persist at birth, suggesting that JAWS is uniquely required for the orientation and consequent positioning of interphalangeal joints within the endochondral skeleton. Jaws mutant mice also exhibit severe chondrodysplasia characterized by delayed and disorganized maturation of growth plate chondrocytes, together with impaired chondroitin sulfation and abnormal metabolism of the chondroitin sulfate proteoglycan aggrecan. Our findings identify JAWS as a key regulator of chondrogenesis and synovial joint positioning required for the restriction of joint formation to discrete stereotyped locations in the embryonic skeleton.

  15. Jaw-neck dysfunction in whiplash-associated disorders.

    PubMed

    Eriksson, Per-Olof; Häggman-Henrikson, Birgitta; Zafar, Hamayun

    2007-04-01

    This paper reports data from recent studies on integrative jaw-neck motor control in healthy subjects and disturbed jaw-neck behaviour in whiplash-associated disorders (WAD). The results show that neck function is an integral part of natural jaw behaviour, and that neck injury can impair jaw function and therefore disturb eating behaviour. We also show preliminary results from implementation of a new approach for rehabilitation of jaw-neck dysfunction and pain in WAD.

  16. Miniplate osteosynthesis of fractures of the edentulous mandible.

    PubMed

    Mugino, Hiroshi; Takagi, Shinji; Oya, Ryoichi; Nakamura, Syoichi; Ikemura, Kunio

    2005-12-01

    This study was performed to analyze treatment of fractures of the edentulous mandible and to discuss this method in relation to the mandibular height at the fracture site. Fifteen fracture sites in 11 patients with an edentulous mandible were retrospectively examined. These fractures were located: nine fractures in the mandibular body, three in the paramedian region, and three in the mandibular angle. Fractures in a mandible measuring more than 10 mm in the vertical height were treated with one miniplate. Fractures in an extremely atrophic mandible with 10 mm or less were treated using one or two miniplates, also using a modified Champy plate with 1.3 mm in thickness. A mandibular fracture with a height of 5 mm was treated with a combination of a microplate on the buccal side and a miniplate on the inferior border of the mandible with additional direct circumferential wiring. Oblique or splitting fractures were treated with direct circumferential wiring or a Herbert screw, at one fracture site each, respectively. Complications, including infection, fibrous union, nonunion and trismus, were not seen. In one patient, hypesthesia of the lower lip was, however, persistent 1 month after surgery. Miniplate osteosynthesis is the less invasive treatment, and it is suitable for fractures of the atrophic edentulous mandible, except for comminuted or defect fractures. To obtain stable fixation in severely atrophic mandibles, we need to consider the use of two miniplates or a combination with microplates. PMID:16311742

  17. Osteochemonecrosis of jaws and bisphosphonates.

    PubMed

    Khosa, A D; Nayyar, M S; Beirne, J C

    2007-03-01

    Osteochemonecrosis of the jaws is a well described side effect of bisphosphonate therapy. Bisphosphonates are non metabolised analogues of pyrophosphate that are capable of localizing to bone, slowing both rate of growth and rate of dissolution therefore reducing the rate of bone turnover. Although the exact mechanism is not clear but it has been established that bisphosphonates target osteoclast, inhibiting their function in several ways: There are two types of bisphosphonates. The first are oral preparations of bisphosphonates, which include Alendronate and Risedronate. They are indicated for the treatment of osteoporosis. They are considered as lower risk of osteochemonecrosis. The second are administered intravenously. Pamindronate is a first generation bisphosphonate; 90 mg administered intravenouly over 2-24 hours every 3-4 weeks. The next generation of intravenous bisphosphonate is Zoldronic acid, which is more effective than Pamidronate in controlling hypercalcaemia of bone and reducing the skeletal related events in patients with metastatic breast cancer, multiple myeloma, hypercalcaemia of malignancy, paget's disease and bone metastasis from prostate and lung cancer.

  18. Osteochemonecrosis of jaws and bisphosphonates.

    PubMed

    Khosa, A D; Nayyar, M S; Beirne, J C

    2007-03-01

    Osteochemonecrosis of the jaws is a well described side effect of bisphosphonate therapy. Bisphosphonates are non metabolised analogues of pyrophosphate that are capable of localizing to bone, slowing both rate of growth and rate of dissolution therefore reducing the rate of bone turnover. Although the exact mechanism is not clear but it has been established that bisphosphonates target osteoclast, inhibiting their function in several ways: There are two types of bisphosphonates. The first are oral preparations of bisphosphonates, which include Alendronate and Risedronate. They are indicated for the treatment of osteoporosis. They are considered as lower risk of osteochemonecrosis. The second are administered intravenously. Pamindronate is a first generation bisphosphonate; 90 mg administered intravenouly over 2-24 hours every 3-4 weeks. The next generation of intravenous bisphosphonate is Zoldronic acid, which is more effective than Pamidronate in controlling hypercalcaemia of bone and reducing the skeletal related events in patients with metastatic breast cancer, multiple myeloma, hypercalcaemia of malignancy, paget's disease and bone metastasis from prostate and lung cancer. PMID:17491545

  19. Implants in conjunction with removable partial dentures: a literature review.

    PubMed

    Mijiritsky, Eitan

    2007-06-01

    Although the benefits of implant-borne removable prostheses are readily apparent for the fully edentulous patient and have been well documented, there is a paucity of studies concerning the combination of implants with removable partial dentures in partially edentulous patients. The aim of this article is to review the literature regarding implants with removable partial dentures and evaluate the evidence for this clinical approach. A MEDLINE/PubMed search from 1990 to 2006, focusing on the use of implants with removable partial dentures and related features, was supplemented with a hand search to identify relevant peer-reviewed English articles published in dental journals and textbooks on removable partial dentures. PMID:17563505

  20. Internal organization in the human jaw muscles.

    PubMed

    Hannam, A G; McMillan, A S

    1994-01-01

    The human jaw muscles are essential to mastication and play an important part in craniofacial growth. They contribute to dental and articular forces, deform the mandible, and, like other tissues, are subject to disorders, often manifested as pain. The literature describes how their contraction is controlled by the nervous system, and how their general structure and function contribute to craniofacial biology, but there has been little appraisal of their internal organization. Most of these muscles are not simple; they are multipennate, complexly layered, and divided by aponeuroses. This arrangement provides substantial means for differential contraction. In many ways, jaw muscle fibers are intrinsically dissimilar from those found in other skeletal muscles, because they are arranged in homogeneous clusters and generally reveal type I or type II histochemical profiles. Most are type I and are distributed preferentially in the anterior and deeper parts of the jaw closers. Additionally, most motor unit (MU) territories are smaller than those in the limbs. There is circumstantial evidence for intramuscular partitioning based in part on innervation by primary muscle nerve branches. During normal function. MU recruitment and the rate coding of MU firing in human jaw muscles follow the general principles established for the limbs, but even here they differ in important respects. Jaw muscle MUs do not have stable force recruitment thresholds and seem to rely more on rate coding than on sequential unit recruitment to grade the amplitude of muscle contraction. Unlike those in the limbs, their twitch tensions correlate weakly with MU fatiguability and contraction speed, probably because there are so few slow, fatigue-resistant MUs in the jaw muscles. Moreover, the type I fibers that are present in such large numbers do not contract as slowly as normally expected. To complicate matters, estimation of jaw MU twitch tensions is extremely difficult, because it is affected by the

  1. Comparison of the reproducibility of panoramic radiographs between dentulous and edentulous patients

    PubMed Central

    Park, Jong-Woong; Huh, Kyung-Hoe; Yi, Won-Jin; Lee, Sam-Sun; Choi, Soon-Chul

    2014-01-01

    Purpose This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients. Materials and Methods The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation. Results In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group. Conclusion Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients. PMID:24944958

  2. Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

    SciTech Connect

    Jensen, Michael D.; Hrinivich, W. Thomas; Jung, Jongho A.; Holdsworth, David W.; Drangova, Maria; Chen, Jeff; Wong, Eugene

    2013-08-15

    Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm{sup 2} were measured using EBT2 film in the center of a 70 × 70 × 22 mm{sup 3} solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm{sup 3}. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm{sup 3} solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm{sup 2}. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to

  3. [Bisphosphonate-related osteonecrosis of the jaw].

    PubMed

    Atanes-Bonome, P; Atanes-Bonome, A; Ríos-Lage, P; Atanes-Sandoval, A D

    2014-04-01

    The bisphosphonates are stable inorganic pyrophosphate analogs that have demonstrated their efficacy in treatment of osteolytic lesions associated with bony metastases, and multiple myeloma, malignant hypercalcemia, Paget's disease, and osteoporosis. Several publications within the last few years have suggested that osteonecrosis of the jaw is associated with bisphosphonate therapy. The diagnosis and management strategies of the patients with bisphosphonate-related osteonecrosis of the jaw is very difficult. It is important for patients to be informed of the risk of this complication, so that they have the opportunity to assess the need for dental treatment before starting therapy. Preventive measures must be taken before, during, and after treatment with bisphosphonates. If osteonecrosis of the jaw is present, management should be conservative: oral chlorhexidine and antibiotics. Surgical treatment should be reserved for those patients who are symptomatic.

  4. Longitudinal effects of clinical therapy and the edentulous state on the transformation of lymphocytes from patients with severe periodontitis.

    PubMed Central

    Baker, J J; Wright, W E; Chan, S P; Oppenheim, J J

    1978-01-01

    Twenty dentulous subjects undergoing clinical therapy for severe periodontitis were used to determine the longitudinal effects of bacterial plaque reduction in vitro lymphocyte transformation. The therapy consisted of either complete extractions or partial extractions and periodontal surgery combined with rigorous oral hygiene. Prior to therapy lymphocytes from these subjects responded significantly to Streptolysin O (SLO) but were not transformed significantly by solubilized dental plaque. However, after therapy lymphocytes from these same subjects responded significantly to both solubilized dental plaque and SLO. This indicates that the severe periodontitis patients were specifically unresponsive to solubilized dental plaque prior to therapy. The mechanism of the unresponsiveness is not clear, but probably does not involve serum factors because supplementation of the lymphocyte cultures with pooled homologous plasma from individuals with gingivitis or moderate periodontitis (instead of the patient's autologous plasma) did not significantly change the mean lymphocyte responses to solubilized dental plaque. In addition, lymphocytes from eleven long-term (5--18 yr) edentulous subjects, who were free of oral inflammation, were significantly transformed by solubilized dental plaque. The latter lymphocyte responses and those of the treated periodontitis patients could be due either to the presence of low levels of oral bacteria in the edentulous mouth or to the lymphocyte transformation assay being a measure of previous antigen sensitization rather than current disease status. In either case, lymphocyte transformation to solubilized dental plaque is not a useful diagnostic tool in periodontitis, but should continue to be a valuable research tool for investigating pathological mechanisms in periodontitis. PMID:737903

  5. Evaluation of the effect of the residual bone angulation on implant-supported fixed prosthesis in mandibular posterior edentulism. Part II: 3-D finite element stress analysis.

    PubMed

    Akça, K; Iplikçioğlu, H

    2001-01-01

    Buccolingual angulation of the mandibular posterior edentulous region may affect the prosthetic load conditions, so as to cause high stress concentrated areas that may easily lead to failure. The aim of this study was to evaluate the effect of various predetermined buccolingual angulation values on stress distribution in the mandibular posterior edentulous region restored with implant-supported fixed partial dentures, using three-dimensional finite element analysis. Stress analyses were performed applying 400N oblique force to implant-supported fixed prosthesis. Stress analyses indicated tensile stress values on the buccal surface and compressive stress values on the lingual surface of cortical bone were increased as the angulation of the edentulous bone increased (especially corresponding to the cervical region of the implants). Compressive stress values, observed where two implants were placed at the second premolar and second molar regions (5-7 design) and first and second molar regions (6-7 design), respectively, were very close to or even exceeded the ultimate compressive strength of bone. It is concluded that when a definite buccolingual angulation is added to other existing risk factors such as bruxism, placing an implant for every missing tooth might reduce the high stress concentration areas. PMID:11813664

  6. Salivary changes related to systemic diseases in the edentulous patients

    PubMed Central

    Preoteasa, E; Tâncu, AM; Iosif, L; Melescanu Imre, M; Murariu-Măgureanu, C; Preoteasa, CT

    2014-01-01

    Introduction: The relatively frequent systemic comorbidities of geriatric patients can be linked to salivary changes, which may induce oral alteration and discomfort with the removable prosthesis. The aim of the study was to evaluate the salivary parameters in completely edentulous patients treated by removable prosthesis, in relation to their general health status. Material and method: A cross-sectional study was performed on 30 completely edentulous patients, 53% male and 47% female, aged between 53 and 84. The evaluation of the salivary parameters (oral hydration index, pH and salivary flow, viscosity and saliva buffer capacity) was performed with the Saliva Check Buffer kit (GC Corporation). Results: The salivary changes encountered were the following: low hydration level (63%), high saliva viscosity (57%), below-average pH (27%), reduced salivary flow (77%) and low saliva buffer capacity (80%). A reduced salivary flow and saliva buffer capacity was found in women. A lower buffer capacity of the saliva was found in patients with respiratory and gastro-intestinal disease. Conclusions: The alterations of the salivary flow are relatively frequent in geriatric patients, removable denture wearers, with compromised systemic status. These changes may be a risk factor for denture stomatitis and oral candidiasis, with a negative effect on the patient’s comfort and quality of life. PMID:25713626

  7. Jaw musculature of Cyclarhis gujanensis (Aves: Vireonidae).

    PubMed

    Previatto, D M; Posso, S R

    2015-08-01

    Cyclarhis gujanensis is a little bird which feeds on high number of large preys, such frogs, lizards, snakes, bats and birds. As there are few studies on the cranial anatomy of this species, we aimed to describe the cranial myology to contribute to the anatomical knowledge of this species and to make some assumptions about functional anatomy. Thus, we described the muscles from the jaw apparatus (external and internal adductor muscles, the muscles of the pterygoid system and the depressor muscles of the mandible). The adductor system is the greatest and multipinulated, particularly in its origin in the caudal portion of the temporal fossa. The depressor jaw muscles systems are enlarged with many components in complexity. The most of jaw apparatus muscles are short, but the strength (biting or crushing forces) from short feeding apparatus fibers probably is increased by high number of components and pinnulation. These anatomical aspects of the muscles indicate a considerable force in the jaws, without which C. gujanensis probably could not cut their prey into smaller pieces. However, functional approaches to analysis of forces of the muscle fibers are needed to corroborate / refute the hypotheses mentioned above. PMID:26421766

  8. Biomechanical considerations on tooth-implant supported fixed partial dentures

    PubMed Central

    Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

    This article discusses the connection of teeth to implants, in order to restore partial edentulism. The main problem arising from this connection is tooth intrusion, which can occur in up to 7.3% of the cases. The justification of this complication is being attempted through the perspective of biomechanics of the involved anatomical structures, that is, the periodontal ligament and the bone, as well as that of the teeth- and implant-supported fixed partial dentures. PMID:23255882

  9. Idiopathic Osteosclerosis of the Jaw in a Brazilian Population: a Retrospective Study

    PubMed Central

    Gusmão, Paulo Henrique Capel; Cardia, Guilherme Saintive; Tolentino, Lívia de Souza; Iwaki, Lilian Cristina Vessoni; Amoroso-Silva, Pablo Andrés

    2014-01-01

    Objectives To report cases of idiopathic osteosclerosis (IO), to review the literature on the subject, and to discuss its main characteristics, diagnosis, differential diagnosis, and treatment. Material and methods Retrospective analysis of 354 panoramic radiographs, searching for IO, its size, shape, location, and noting patients’ demographic information. Literature review used Medline and Lilacs databases and the terms idiopathic osteosclerosis OR bone sclerosis OR dense bone island AND jaws. Results IO was identified in 5.6% of the radiographs (n=20 patients, 22 foci). Patients were healthy, with an age ranging from 5 to 51 years (mean=29.8), with male-female ratio of 3:2. IOs were found mainly in the premolar/molar region, at root apices, between roots, away from the teeth, laterally to the tooth, and in edentulous areas. The distribution between right and left sides of the jaw was equal for the 22 foci, with only one case in the maxilla. IOs were localized, well-defined, radiopaque, mostly round or ovoid in shape, but sometimes irregular. In some cases, IOs were similar to condensing osteitis, but differential diagnosis also considered complex odontoma, focal cemento-osseous dysplasia, and residual roots. Twenty studies on the topic were reviewed. Conclusions Incidence of IO in the Brazilian sample was 5.6%, with age ranging from 5 to 51 years (mean=29.8), and male-female ratio of 3:2. The radiopacities occurred in different locations, with significant prevalence in the mandible. The findings and the literature review corroborate the hypothesis that IO should be considered developmental variation of normal bone that does not require treatment.

  10. Dental implants for severely atrophied jaws due to ectodermal dysplasia.

    PubMed

    Balaji, Preetha; Balaji, S M; Ugandhar, Prashanthi

    2015-01-01

    The aim was to present the successful esthetical and functional rehabilitation of partial anodontia in a case of severe ectodermal dysplasia with complete atrophy of the jaws. A 17-year-old male with Class III malocclusion with partial anodontia sought dental implant treatment. His expectation was that of Class I occlusion. The challenge in the case was to match the expectation, reality, and the clinical possibilities. Ridge augmentation was performed with a combination of rib graft and recombinant human bone morphogenetic protein-2. Simultaneously, 6 implants (Nobel Biocare™ - Tapered Groovy) were placed in maxillary arch and 10 in the mandible. Simultaneous placement ensured faster and better osseointegration though a mild compromise of the primary stability was observed initially. After adequate healing, Customized Zirconia Procera™ system was used to build the framework. Zirconia crown was cemented to the framework. Radiological and clinical evidence of osseointegration was observed in all 16 dental implants. Successful conversion of Class III to Class I occlusion was achieved with the combination of preprosthetic alveolar ridge augmentation, Procera™ Implant Bridge system. Abnormal angulations and or placement of dental implants would result in failure of the implant. Hence conversion of Class III to Class I occlusion needs complete and complex treatment planning so that the entire masticatory apparatus is sufficiently remodeled. Planning should consider the resultant vectors that would otherwise result in failure of framework or compromise the secondary stability of the dental implant during function. A successful case of rehabilitation of complex partial anodontia is presented. PMID:26096119

  11. Towards predicting biomechanical consequences of jaw reconstruction.

    PubMed

    Stavness, Ian; Hannam, Alan G; Lloyd, John E; Fels, Sidney

    2008-01-01

    We are developing dynamic computer models of surgical jaw reconstructions in order to determine the effect of altered musculoskeletal structure on the biomechanics of mastication. We aim to predict post-reconstruction deficits in jaw motion and force production. To support these research goals we have extended our biomechanics simulation toolkit, ArtiSynth [1], with new methods relevant to surgical planning. The principle features of ArtiSynth include simulation of constrained rigid-bodies, volume-preserving finite-element methods for deformable bodies, contact between bodies, and muscle models. We are adding model editing capabilities and muscle activation optimization to facilitate progress on post-surgical simulation. Our software and research directions are focused on upper-airway and cranio-facial anatomy, however the toolset and methodology are applicable to other musculoskeletal systems.

  12. Prosthetic rehabilitation of edentulous patient with limited oral access: A clinical report

    PubMed Central

    Kumar, Sandeep; Arora, Aman; Yadav, Reena

    2012-01-01

    Microstomia may result from surgical treatment of orofacial neoplasms, cleft lips, maxillofacial trauma, burns, radiotherapy or scleroderma. A maximal oral opening that is smaller than the size of a complete denture can make prosthetic treatment challenging. This clinical report presents the prosthodontic management of a total edentulous patient with microstomia. Sectional mandibular and maxillary trays and foldable mandibular and maxillary denture were fabricated for the total edentulous patient. PMID:23293498

  13. Removable partial denture design using milled abutment surfaces and minimal soft tissue coverage for periodontally compromised teeth: a clinical report.

    PubMed

    Chaiyabutr, Yada; Brudvik, James S

    2008-04-01

    This clinical report describes the treatment of a partially edentulous patient with periodontally compromised teeth using a combination of single crowns and a removable partial denture (RPD). The RPD was designed to combine the benefits of milled surfaces and hygienic principles while allowing modification and addition of artificial teeth, should natural teeth be lost.

  14. The characters of Palaeozoic jawed vertebrates

    PubMed Central

    Brazeau, Martin D; Friedman, Matt

    2014-01-01

    Newly discovered fossils from the Silurian and Devonian periods are beginning to challenge embedded perceptions about the origin and early diversification of jawed vertebrates (gnathostomes). Nevertheless, an explicit cladistic framework for the relationships of these fossils relative to the principal crown lineages of the jawed vertebrates (osteichthyans: bony fishes and tetrapods; chondrichthyans: sharks, batoids, and chimaeras) remains elusive. We critically review the systematics and character distributions of early gnathostomes and provide a clearly stated hierarchy of synapomorphies covering the jaw-bearing stem gnathostomes and osteichthyan and chondrichthyan stem groups. We show that character lists, designed to support the monophyly of putative groups, tend to overstate their strength and lack cladistic corroboration. By contrast, synapomorphic hierarchies are more open to refutation and must explicitly confront conflicting evidence. Our proposed synapomorphy scheme is used to evaluate the status of the problematic fossil groups Acanthodii and Placodermi, and suggest profitable avenues for future research. We interpret placoderms as a paraphyletic array of stem-group gnathostomes, and suggest what we regard as two equally plausible placements of acanthodians: exclusively on the chondrichthyan stem, or distributed on both the chondrichthyan and osteichthyan stems. PMID:25750460

  15. [Comparative analysis of edentulous patients treated traditionally and with the use of a face-bow and Quick Master articulator].

    PubMed

    Kubrak, J

    1998-01-01

    Correct determination of the occlusal plane is one of the most difficult stages of treatment. After determining the correct occlusal plane its reproduction is possible thanks to the use of articulators. These instruments simulate movements of the jaw in three planes. One of the most optimal articulators is a semi-adjustable type. These instruments are not complicated and give good treatment results. A modern semiadjustable type of articulator is Quick Master. The face-bow which comes together with this instrument is used for recording and transferring the occlusal relation to the articulator. This allows to mount models in an adequate three dimensional position in relation to the temporo-mandibular joint. The use of these instruments leads to many questions and doubts due to difficulties in their use. Therefore the aim of my study was to elaborate a simple method of occlusal recording. I have also compared the treatment results of edentulous patients treated with the use of an articulator and the use of a traditional method. Prosthetic restorations were prepared among 60 patients. The study material was divided into two groups of 30 patients each. In the control group for preparing complete dentures the Gysi method was employed as the most common. In the study group a face-bow and articulator were used. After preparing complete dentures detailed clinical control examinations were carried out and were repeated 24-48 hours after fitting the dentures and also after 3 and 6 months of their use. Working with the face-bow I have employed my own modification of recording the occlusion. The upper wax rim was placed on a slightly warmed bite fork and drawing pins were placed in the recording block to act as a type of key. The lower rim was warmed and brought to occlusal contact a couple of times. Next the face-bow was inserted. The recorded occlusion was transferred and mounted in the articulator. Teeth in both cases were set up similarly to the Gysi method. Lower teeth

  16. [Experience of systematization on the treatment of patients with upper jaws fractures, during the period 1991-2000].

    PubMed

    Khinkov, D

    2005-01-01

    A retrospecive analysis was done of the 128 patients with fractures in a upper jaw, treated during the period 1991-2000. The treatment of the patients with partial fractures in a alveolar part of maxilla and frontal wall of maxillary sinus, consist of debridement on the open wound, primery stiched and stabilization by arch bar of perspective teeth. In the cases with fractures of tuber maxilla and opening of maxillary sinus they tray to clouse it by Rhermann technique, with or without radical antrothomy by Caldwell-Luc technique. On the patients by total upper jaw fractures they try lead by princip of duble stage fixation: from one side-of intact upper bone structures and the other side-on a mandible. On the cases of upper jaw fractures, combine with barain traums. was treated conservativly - the specialize treatment of facial injures was postpoun until stabilization of brain status.

  17. Medication-related osteonecrosis of the jaw: a dentist's nightmare.

    PubMed

    Muthukrishnan, Arvind; Bijai Kumar, Laliytha; Ramalingam, Gomathi

    2016-01-01

    Medication-related osteonecrosis of the jaw (MRONJ) is a complication in patients who are on anti-bone resorptive drugs. These drugs are prescribed for patients with multiple myeloma, osteoporosis, metastatic carcinoma and Paget's disease. Common anti-bone resorptive drugs such as bisphosphonate and monoclonal antibodies such as denosumab are prescribed for these patients to prevent bone resorption. Although very effective in preventing bone resorption, a complication arising from these groups of drugs is the development of osteomyelitis of the jaw. This medication-related osteonecrosis occurs only in the jaw bones. It could mimic a metastatic jaw tumour when a patient reports to the dental surgeon with pain and swelling in the jaw. This case report describes MRONJ in a 50-year-old Indian woman. This possible painful drug-induced complication of jaw bones can be prevented if proper medical history is taken and management protocol is followed in these patients. PMID:27053542

  18. [Acrylic resin removable partial dentures].

    PubMed

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  19. Eating with a saw for a jaw: functional morphology of the jaws and tooth-whorl in Helicoprion davisii.

    PubMed

    Ramsay, Jason B; Wilga, Cheryl D; Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Schlader, Robert; Didier, Dominique A

    2015-01-01

    The recent reexamination of a tooth-whorl fossil of Helicoprion containing intact jaws shows that the symphyseal tooth-whorl occupies the entire length of Meckel's cartilage. Here, we use the morphology of the jaws and tooth-whorl to reconstruct the jaw musculature and develop a biomechanical model of the feeding mechanism in these early Permian predators. The jaw muscles may have generated large bite-forces; however, the mechanics of the jaws and whorl suggest that Helicoprion was better equipped for feeding on soft-bodied prey. Hard shelled prey would tend to slip anteriorly from the closing jaws due to the curvature of the tooth-whorl, lack of cuspate teeth on the palatoquadrate (PQ), and resistance of the prey. When feeding on soft-bodied prey, deformation of the prey traps prey tissue between the two halves of the PQ and the whorl. The curvature of the tooth-whorl and position of the exposed teeth relative to the jaw joint results in multiple tooth functions from anterior to posterior tooth that aid in feeding on soft-bodied prey. Posterior teeth cut and push prey deeper into the oral cavity, while middle teeth pierce and cut, and anterior teeth hook and drag more of the prey into the mouth. Furthermore, the anterior-posterior edges of the teeth facilitate prey cutting with jaw closure and jaw depression. The paths traveled by each tooth during jaw depression are reminiscent of curved pathways used with slashing weaponry such as swords and knifes. Thus, the jaws and tooth-whorl may have formed a multifunctional tool for capturing, processing, and transporting prey by cyclic opening and closing of the lower jaw in a sawing fashion.

  20. Thermal resilient multiple jaw braze fixture

    DOEpatents

    Ney, Robert; Perrone, Alex J.

    1995-07-11

    A braze fixture has side walls forming a cavity with an opening to receive a stack of parts to be brazed. Sidewalls of the housing have a plurality of bearing receiving openings into which bearing rods or jaws are inserted to align the stacked elements of the workpiece. The housing can also have view ports to allow a visual check of the alignment. Straps or wires around the fixture are selected to have thermal characteristics similar to the thermal characteristics of the workpiece undergoing brazing. The straps or wires make physical contact with the bearing rods thereby causing bearing rods to maintain the workpiece in proper alignment throughout the entire brazing cycle.

  1. [Morphometric study of total edentulous maxilla of Moroccan subjects].

    PubMed

    Zeroual, R; Andoh, A; El Mouahid, N; Chemlali, S

    2014-09-01

    Despite the importance of taking the primary dental impression, this act remains unfortunately neglected by most practitioners. Think to succeed a total removable prosthesis from a failed primary dental impression is a challenge for the practitioner and seems utopia. For this, you wish through our work give the importance to the choice of the mass-produced impression tray that is paramount for the success of the primary dental impression. This study examines a sample of 160 plaster primary models (80 maxillary and 80 mandibular) from primary dental impression carried out with mass-produced impression trays whether or not modified for new total edentulous patients having consulted at the University Dental centre in Casablanca for a prosthetic rehabilitation by total prosthesis. Thirty-six women and 44 men have been selected. The study showed that men have maxillary and mandibular arches longer and wider than those of women, and that the average value for several parameters measured is close to the measurements of the maxilla trays U3 and mandibular L3; Where the need for acquisition of large size dental impression tray, in accordance with the dimensions of our population in order to meet our expectations, namely: to respect the integrity of the support surfaces, to meet the mechanical qualities of the prosthesis, to restore the aesthetics and function by minimizing the grievances of the toothless total subject.

  2. Edentulousness and oral rehabilitation: experiences from the patients' perspective.

    PubMed

    Trulsson, Ulrika; Engstrand, Per; Berggren, Ulf; Nannmark, Ulf; Brånemark, Per-Ingvar

    2002-12-01

    The psychological effects of tooth loss in the permanent dentition are relatively unknown. Complete edentulousness is a serious life event in terms of readjustment. The aim of the study was to describe the process patients with deteriorating dental status had gone through before treatment with a fixed prosthesis (Brånemark System, Novum), and to describe what living with a fixed prosthesis means to the patients themselves. In-depth interviews were carried out with 18 patients, and the interviews were transcribed verbatim and analysed in open, axial and selective coding processes according to Grounded Theory. In the analysis, four categories were developed and labelled: 'alterations in self-image', 'becoming a deviating person', 'becoming an uncertain person' and 'becoming the person I once was'. 'Alterations in self-image' was identified as the core category and was related to the other three categories. The core category describes the changes in self-image starting with the subjects' increasingly worsened dental status, followed by a period of them having to live and cope with a denture and, finally, their living with a fixed prosthesis. The motive power for the decision to undergo treatment with a fixed prosthesis seems to be a desire to restore dental status and also to recapture attractiveness, self-esteem and a positive self-image. PMID:12507214

  3. [Morphometric study of total edentulous maxilla of Moroccan subjects].

    PubMed

    Zeroual, R; Andoh, A; El Mouahid, N; Chemlali, S

    2014-09-01

    Despite the importance of taking the primary dental impression, this act remains unfortunately neglected by most practitioners. Think to succeed a total removable prosthesis from a failed primary dental impression is a challenge for the practitioner and seems utopia. For this, you wish through our work give the importance to the choice of the mass-produced impression tray that is paramount for the success of the primary dental impression. This study examines a sample of 160 plaster primary models (80 maxillary and 80 mandibular) from primary dental impression carried out with mass-produced impression trays whether or not modified for new total edentulous patients having consulted at the University Dental centre in Casablanca for a prosthetic rehabilitation by total prosthesis. Thirty-six women and 44 men have been selected. The study showed that men have maxillary and mandibular arches longer and wider than those of women, and that the average value for several parameters measured is close to the measurements of the maxilla trays U3 and mandibular L3; Where the need for acquisition of large size dental impression tray, in accordance with the dimensions of our population in order to meet our expectations, namely: to respect the integrity of the support surfaces, to meet the mechanical qualities of the prosthesis, to restore the aesthetics and function by minimizing the grievances of the toothless total subject. PMID:25975064

  4. Exploratory factor analysis of the Brazilian OHIP for edentulous subjects.

    PubMed

    Souza, R F; Leles, C R; Guyatt, G H; Pontes, C B; Della Vecchia, M P; Neves, F D

    2010-03-01

    The use of seven domains for the Oral Health Impact Profile (OHIP)-EDENT was not supported for its Brazilian version, making data interpretation in clinical settings difficult. Thus, the aim of this study was to assess patients' responses for the translated OHIP-EDENT in a group of edentulous subjects and to develop factor scales for application in future studies. Data from 103 conventional and implant-retained complete denture wearers (36 men, mean age of 69.1 +/- 10.3 years) were assessed using the Brazilian version of the OHIP-EDENT. Oral health-related quality of life domains were identified by factor analysis using principal component analysis as the extraction method, followed by varimax rotation. Factor analysis identified four factors that accounted for 63% of the 19 items total variance, named masticatory discomfort and disability (four items), psychological discomfort and disability (five items), social disability (five items) and oral pain and discomfort (five items). Four factors/domains of the Brazilian OHIP-EDENT version represent patient-important aspects of oral health-related quality of life.

  5. Edentulism risk indicators among Mexican elders 60-year-old and older.

    PubMed

    Islas-Granillo, H; Borges-Yañez, S A; Lucas-Rincón, S E; Medina-Solís, C E; Casanova-Rosado, A J; Márquez-Corona, M L; Maupomé, G

    2011-01-01

    The objective of this study was to determine the prevalence of edentulism in Mexican elders aged 60 years and older, and the associated risk indicators. A cross-sectional study was undertaken in 139 elders living in either of two long-term care (LTC) facilities, or attending an adult day center (ADC) in Pachuca, Mexico. A subject was edentulous when natural teeth were completely absent, determined through a clinical examination. Risk indicators were collected using questionnaires. Analyses were performed using binary logistic regression in STATA 9.0. Mean age was 79.0±9.8 years. Many subjects were women (69.1%). The prevalence of edentulism was 36.7%. In multivariate analysis, after adjusting for age and sex, the variables that were inversely associated (p<0.05) with edentulism were living with a spouse (odds ratio=OR=0.31), and lacking health insurance (OR=0.70). Variables associated with higher risk of being edentate were lower educational attainment (OR=1.61), having received radiation therapy (OR=4.49), being a smoker (OR=4.82), and having diabetes (OR=2.94) or other chronic illnesses (OR=1.82) (with hypertension approaching significance, p=0.067). In this sample of Mexican elders, diverse variables were associated with edentulism, in particular smoking and past radiotherapy. Oral health programs within and outside LTC/ADC should take into account risk factors specific to the older population.

  6. Jaw muscles of New World squirrels.

    PubMed

    Ball, S S; Roth, V L

    1995-06-01

    The jaw, suprahyoid, and extrinsic tongue muscles are described for eight species of New World squirrels, spanning more than an order of magnitude in body mass. Anatomical differences are discussed in the light of body size, natural history, and phylogeny. The relative sizes of different muscles, their orientations, and the shapes and positions of their areas of attachment vary but show few trends in relation to body size. The anatomical differences are likewise not readily explained by the mechanical requirements of the animals' diets, which are similar. The most marked anatomical differences occur in Sciurillus (the pygmy tree squirrel), as well as those genera--Glaucomys (the flying squirrel) and Tamias (the chipmunk)--that are taxonomically most distinct from the tree squirrels. Sciurillus is noteworthy for its unusually small temporalis and an anterior deep masseter that is oriented to assist in retraction of the jaw. Tamias has a more vertically oriented temporalis and greater inclination in the anterior masseter muscles than the other squirrels, features that may be associated with its large diastema and relatively posteriorly situated cheek teeth, which in turn may relate to its having cheek pouches. Our results form a valuable database of information to be used in further studies of functional morphology and phylogeny. PMID:7541086

  7. Bisphophonates related osteonecrosis of the jaw

    PubMed Central

    Gupta, Swati; Gupta, Hemant; Mandhyan, Devendra; Srivastava, Sanjeev

    2013-01-01

    Objective: With sporadic reporting of BPs related osteonecrosis of jaw and in absence of definitive guidelines regarding the management of such patients, the dentists and the oral and maxillofacial surgeons need to be updated about this issue. The objective of this article was to produce an updated bibliographic review of BPs related ONJ. This paper reviews the literature regarding the same for better understanding of the problem and its management. Background: Bisphosphonates (BPs) are potent inhibitors of bone resorption and are widely used in the treatment of osteoporosis and other diseases that cause bone mass loss, such as Paget's disease, bone metastases, and multiple myeloma, to prevent pathological fractures. With increasing use, evidence is emerging that patients taking BP drugs are at risk of developing osteonecrosis of the jaws (ONJs), sometimes occurring spontaneously, but more commonly following dental extractions or oral bone surgery. Materials and Methods: A bibliographic search was carried out using PubMed, Medline, and search engines ending in April, 2013. The search terms used were: Oral BPs, dental implants, and osteonecrosis. Conclusion: On the basis of available literature, the management of patients on bisphosphonates requiring dental treatment is classified according to the duration of BPs treatment, method of administration of BPs etc. Dental treatments when planned carefully in such patients have a fair to good prognosis. PMID:24665168

  8. Dental Implants Installed in Irradiated Jaws

    PubMed Central

    Chambrone, L.; Mandia, J.; Shibli, J.A.; Romito, G.A.; Abrahao, M.

    2013-01-01

    The aim of this study was to assess the survival rate of titanium implants placed in irradiated jaws. MEDLINE, EMBASE, and CENTRAL were searched for studies assessing implants that had been placed in nongrafted sites of irradiated patients. Random effects meta-analyses assessed implant loss in irradiated versus nonirradiated patients and in irradiated patients treated with hyperbaric oxygen (HBO) therapy. Of 1,051 potentially eligible publications, 15 were included. A total of 10,150 implants were assessed in the included studies, and of these, 1,689 (14.3%) had been placed in irradiated jaws. The mean survival rate in the studies ranged from 46.3% to 98.0%. The pooled estimates indicated a significant increase in the risk of implant failure in irradiated patients (risk ratio: 2.74; 95% confidence interval: 1.86, 4.05; p < .00001) and in maxillary sites (risk ratio: 5.96; 95% confidence interval: 2.71, 13.12; p < .00001). Conversely, HBO therapy did not reduce the risk of implant failure (risk ratio: 1.28; 95% confidence interval: 0.19, 8.82; p = .80). Radiotherapy was linked to higher implant failure in the maxilla, and HBO therapy did not improve implant survival. Most included publications reported data on machined implants, and only 3 studies on HBO therapy were included. Overall, implant therapy appears to be a viable treatment option for reestablishing adequate occlusion and masticatory conditions in irradiated patients. PMID:24158336

  9. Prognostic factors in patients with jaw sarcomas.

    PubMed

    Vadillo, Rafael Morales; Contreras, Sonia Julia Sacsaquispe; Canales, Janet Ofelia Guevara

    2011-01-01

    The aim of this study was to identify the prognostic factors related to the survival of patients with sarcomas of the jaw treated in the Dr. Eduardo Caceres Graziani National Institute for Neoplastic Diseases, Lima, Peru. Age, gender, delay in consultation, diagnostic delay, therapeutic delay, tumor size, tumor location, facial asymmetry, pain, treatment type, and histopathological diagnosis were all evaluated as possible prognostic factors that would influence survival in those with jaw sarcomas. In the analysis, the following was used: mortality tables, Kaplan-Meier's product-limit method, log-rank, and Breslow and Tarone-Ware tests; for the prognostic factors, Cox's Regression Model was used. The overall survival rate, with the patient being free from disease at two years, was 55%, and that at five years was 45%. In the independent analysis of the prognostic factors, four variables were statistically significant in influencing survival: gender (p = 0.043), histopathologic diagnosis (p = 0.019), tumor location (p = 0.019), and treatment type (p = 0.030). According to Cox's Regression Model for the multivariate analysis, statistically significant prognostic factors were: gender (p = 0.086), tumor location (p = 0.020), and treatment type (p = 0.092). Thus, the variables of gender, tumor location, and treatment type were determined to be predictive factors for prognosis of survival.

  10. Bisphosphonate-associated osteonecrosis of the jaws.

    PubMed

    Agarwal, Pankaj; Rao, Nirmala N

    2012-01-01

    Bisphosphonates constitute a group of drugs capable of modulating bone turnover and reduce its remodeling when an excessive resorption occurs. This is why they are indicated in a large group of bone diseases like postmenopausal osteoporosis or osteolysis associated with breast cancer or multiple myeloma. Over the last few years and due to their extensive use, many cases of complications associated with their use have been published. Among the most important possible adverse effects are the oral ones, with the appearance of ulcerations and, especially, osteonecrosis of the jaws associated with this therapy. In this paper, we have analyzed the general characteristics of these drugs and their mechanisms of action as well as the described adverse effects, especially oral and maxillofacial, have been made special reference, regarding the prevention of osteonecrosis of the jaws, heightened by cases described in the medical and odontological literature. The preventive protocol backs up the fundamental role of the odontologist in the effective prevention of this process before, during and after the treatment. PMID:22842261

  11. Vinyl polysiloxane impression material in removable prosthodontics. Part 1: edentulous impressions.

    PubMed

    Massad, Joseph J; Cagna, David R

    2007-08-01

    Recent advances in impression materials and stock edentulous impression trays have resulted in simplified approaches to impression making in removable prosthodontics. Once considered an absolute necessity, it is now possible to avoid the need for custom impression trays. In an effort to achieve reliable master casts in a single appointment, new and innovative procedures are now available. This article, the first in a 3-part series, will review historical information, basic concepts, materials considerations, and philosophic approaches to impression making in complete-denture therapy. A modem technique using readily available impression materials will be described and illustrated so readers can consider the benefits of incorporation into their daily management of edentulous patients.

  12. Vinyl polysiloxane impression material in removable prosthodontics. Part 1: Edentulous impressions.

    PubMed

    Massad, Joseph J; Cagna, David R

    2009-02-01

    Recent advances in impression materials and stock edentulous impression trays have resulted in simplified approaches to impression making in removable prosthodontics. Once considered an absolute necessity, it is now possible to avoid the need for custom impression trays. In an effort to achieve reliable master casts in a single appointment, new and innovative procedures are now available. This article, the first in a 3-part series, will review historical information, basic concepts, materials considerations, and philosophic approaches to impression making in complete-denture therapy. A modern technique using readily available impression materials will be described and illustrated so readers can consider the benefits of incorporation into their daily management of edentulous patients.

  13. Actinomyces meyeri: from "lumpy jaw" to empyema.

    PubMed

    Attaway, A; Flynn, T

    2013-10-01

    While the most common presentation of actinomycosis is cervicofacial disease, or "lumpy jaw syndrome," Actinomyces meyeri has a predilection for pulmonary disease as well as dissemination to distant organs. We describe a 61-year-old Caucasian male with a relapsing-remitting mandibular sinus tract who would go on to develop weight loss, dyspnea, and a cough productive of malodorous sputum. Imaging revealed a right lower lobe pneumonia and a large left sided empyema. He underwent thoracotomy and decortication on the left side, and 1 L of foul-smelling purulent fluid was drained. Culture grew Actinomyces meyeri. He completed an extended antibiotic course and had his teeth extracted with good clinical outcome.

  14. Jaw-muscle architecture and mandibular morphology influence relative maximum jaw gapes in the sexually dimorphic Macaca fascicularis.

    PubMed

    Terhune, Claire E; Hylander, William L; Vinyard, Christopher J; Taylor, Andrea B

    2015-05-01

    Maximum jaw gape is a performance variable related to feeding and non-feeding oral behaviors, such as canine gape displays, and is influenced by several factors including jaw-muscle fiber architecture, muscle position on the skull, and jaw morphology. Maximum gape, jaw length, and canine height are strongly correlated across catarrhine primates, but relationships between gape and other aspects of masticatory apparatus morphology are less clear. We examine the effects of jaw-adductor fiber architecture, jaw-muscle leverage, and jaw form on gape in an intraspecific sample of sexually dimorphic crab-eating macaques (Macaca fascicularis). As M. fascicularis males have relatively larger maximum gapes than females, we predict that males will have muscle and jaw morphologies that facilitate large gape, but these morphologies may come at some expense to bite force. Male crab-eating macaques have relatively longer jaw-muscle fibers, masseters with decreased leverage, and temporomandibular joint morphologies that facilitate the production of wide gapes. Because relative canine height is correlated with maximum gape in catarrhines, and males have relatively longer canines than females, these results support the hypothesis that male M. fascicularis have experienced selection to increase maximum gape. The sexes do not differ in relative masseter physiologic cross-sectional area (PCSA), but males compensate for a potential trade-off between muscle excursion versus muscle force with increased temporalis weight and PCSA. This musculoskeletal configuration is likely functionally significant for behaviors involving aggressive canine biting and displays in male M. fascicularis and provides additional evidence supporting the multifactorial nature of the catarrhine masticatory apparatus. Our results have implications for the evolution of craniofacial morphology in catarrhine primates and reinforce the importance of evaluating additional factors other than feeding behavior and diet

  15. Stereotactic arc therapy for small elongated tumors using cones and collimator jaws; dosimetric and planning aspects

    SciTech Connect

    Pooter, J.A. de; Essers, M.; Nowak, P.J.C.M.; Pan, C. de; Heijmen, B.J.M.; Levendag, P.C.

    2004-12-01

    Stereotactic arc treatment of small intracranial tumors is usually performed with arcs collimated by circular cones, resulting in treatment volumes which are basically spherical. For nonspherical lesions this results in a suboptimal dose distribution. Multiple isocenters may improve the dose conformity for these lesions, at the cost of large overdosages in the target volume. To achieve improved dose conformity as well as dose homogeneity, the linac jaws (with a minimum distance of 1.0 cm to the central beam axis) can routinely be used to block part of the circular beams. The purpose of this study was to investigate the feasibility of blocking cones with diameters as small as 1.0 cm and a minimum distance between the jaw and the central beam axis of 0.3 cm. First, the reproducibility in jaw positioning and resulting dose delivery on the treatment unit were assessed. Second, the accuracy of the TPS dose calculation for these small fields was established. Finally, clinically applied treatment plans using nonblocked cones were compared with plans using the partially blocked cones for several treatment sites. The reproducibility in dose delivery on our Varian Clinac 2300 C/D machines on the central beam axis is 0.8% (1 SD). The accuracy of the treatment planning system dose calculation algorithm is critically dependent on the used fits for the penumbra and the phantom scatter. The average deviation of calculated from measured dose on the central beam axis is -1.0%{+-}1.4% (1 SD), which is clinically acceptable. Partial cone blocking results in improved dose distributions for elongated tumors, such as vestibular schwannoma and uveal melanoma. Multiple isocenters may be avoided. The technique is easy to implement and requires no additional workload.

  16. Stereotactic arc therapy for small elongated tumors using cones and collimator jaws; dosimetric and planning aspects.

    PubMed

    de Pooter, J A; Essers, M; Nowak, P J C M; de Pan, C; Heijmen, B J M; Levendag, P C

    2004-12-01

    Stereotactic arc treatment of small intracranial tumors is usually performed with arcs collimated by circular cones, resulting in treatment volumes which are basically spherical. For nonspherical lesions this results in a suboptimal dose distribution. Multiple isocenters may improve the dose conformity for these lesions, at the cost of large overdosages in the target volume. To achieve improved dose conformity as well as dose homogeneity, the linac jaws (with a minimum distance of 1.0 cm to the central beam axis) can routinely be used to block part of the circular beams. The purpose of this study was to investigate the feasibility of blocking cones with diameters as small as 1.0 cm and a minimum distance between the jaw and the central beam axis of 0.3 cm. First, the reproducibility in jaw positioning and resulting dose delivery on the treatment unit were assessed. Second, the accuracy of the TPS dose calculation for these small fields was established. Finally, clinically applied treatment plans using nonblocked cones were compared with plans using the partially blocked cones for several treatment sites. The reproducibility in dose delivery on our Varian Clinac 2300 C/D machines on the central beam axis is 0.8% (1 SD). The accuracy of the treatment planning system dose calculation algorithm is critically dependent on the used fits for the penumbra and the phantom scatter. The average deviation of calculated from measured dose on the central beam axis is -1.0%+/-1.4% (1 SD), which is clinically acceptable. Partial cone blocking results in improved dose distributions for elongated tumors, such as vestibular schwannoma and uveal melanoma. Multiple isocenters may be avoided. The technique is easy to implement and requires no additional workload. PMID:15651627

  17. Epithelial jaw cysts: analysis of 126 Nigerian cases.

    PubMed

    Ogunlewe, M O; Odukoya, O; Akinwande, J A

    1996-01-01

    One hundred and twenty-six Nigerian cases of epithelial jaw cysts were retrieved from case notes and biopsy records of the Department of Oral and Maxillofacial Surgery and Department of Oral Pathology and Oral Biology of the Lagos University Teaching Hospital. The cases were analysed for age, sex, site and methods of management. Results show that developmental odontogenic cysts (57.14%) were more common than inflammatory odontogenic cysts (26.94%). Dentigerous cyst (22.22%) was the most common epithelial jaw cyst, followed by radicular cyst (21.43%). Developmental non-odontogenic cysts were more than twice as common in females as in males. Sixty-eight per cent of epithelial jaw cysts were treated by enucleation, 10% by marsupialisation, 13% by jaw resection and 9% by surgical excision.

  18. Design Documentation for JaWE2Openflow Project

    SciTech Connect

    Mehta, N; Barter, R H

    2004-07-29

    Lawrence Livermore National Laboratory (LLNL) has chosen CIGNEX Technologies, Inc. (CIGNEX) to design and develop the JaWE2Openflow conversion software. This document was created by CIGNEX as a project deliverable.

  19. Monte Carlo-based simulation of dynamic jaws tomotherapy

    SciTech Connect

    Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S.

    2011-09-15

    Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is greater than 30% of the prescription dose (gamma analysis

  20. Caecilian jaw-closing mechanics: integrating two muscle systems.

    PubMed

    Kleinteich, Thomas; Haas, Alexander; Summers, Adam P

    2008-12-01

    Caecilians (Lissamphibia: Gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. Using data from high-resolution X-ray radiation computed tomography scans, we modelled the effect of these two muscle groups (mm. levatores mandibulae and m. interhyoideus posterior) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. Measurements of lever arm lengths, muscle fibre orientations and physiological cross-sectional area of cranial muscles were available from three caecilian species: Ichthyophis cf. kohtaoensis; Siphonops annulatus; and Typhlonectes natans. The maximal gape of caecilians is restricted by a critical gape angle above which the mm. levatores mandibulae will open the jaw and destabilize the mandibular joint. The presence of destabilizing forces in the caecilian jaw mechanism may be compensated for by a mandibular joint in that the fossa is wrapped around the condyle to resist dislocation. The caecilian skull is streptostylic; the quadrate-squamosal complex moves with respect to the rest of the skull. This increases the leverage of the jaw-closing muscles. We also demonstrate that the unusual jaw joint requires streptostyly because there is a dorsolateral movement of the quadrate-squamosal complex when the jaw closes. The combination of the two jaw-closing systems results in high bite forces over a wide range of gape angles, an important advantage for generalist feeders such as caecilians. The relative sizes and leverage mechanics of the two closing systems allow one to exert more force when the other has a poor mechanical advantage. This effect is seen in all three species we examined. In the aquatic T. natans, with its less well-roofed skull, there is a larger contribution of the mm. levatores mandibulae to total bite force than in the terrestrial I. cf. kohtaoensis and S. annulatus.

  1. Evolutionary Trends in the Jaw Adductor Mechanics of Ornithischian Dinosaurs.

    PubMed

    Nabavizadeh, Ali

    2016-03-01

    Jaw mechanics in ornithischian dinosaurs have been widely studied for well over a century. Most of these studies, however, use only one or few taxa within a given ornithischian clade as a model for feeding mechanics across the entire clade. In this study, mandibular mechanical advantages among 52 ornithischian genera spanning all subclades are calculated using 2D lever arm methods. These lever arm calculations estimate the effect of jaw shape and difference in adductor muscle line of action on relative bite forces along the jaw. Results show major instances of overlap between taxa in tooth positions at which there was highest mechanical advantage. A relatively low bite force is seen across the tooth row among thyreophorans (e.g., stegosaurs and ankylosaurs), with variation among taxa. A convergent transition occurs from a more evenly distributed bite force along the jaw in basal ornithopods and basal marginocephalians to a strong distal bite force in hadrosaurids and ceratopsids, respectively. Accordingly, adductor muscle vector angles show repeated trends from a mid-range caudodorsal orientation in basal ornithischians to a decrease in vector angles indicating more caudally oriented jaw movements in derived taxa (e.g., derived thyreophorans, basal ornithopods, lambeosaurines, pachycephalosaurs, and derived ceratopsids). Analyses of hypothetical jaw morphologies were also performed, indicating that both the coronoid process and lowered jaw joint increase moment arm length therefore increasing mechanical advantage of the jaw apparatus. Adaptive trends in craniomandibular anatomy show that ornithischians evolved more complex feeding apparatuses within different clades as well as morphological convergences between clades. PMID:26692539

  2. Jaw Dislocation as an Unusual Complication of Upper Endoscopy

    PubMed Central

    Dellon, Evan S.; Steele, David

    2016-01-01

    This case report presents an unusual complication of upper endoscopy, resulting in jaw dislocation. Temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation, but it is not widely recognized as a complication of gastrointestinal endoscopy. This report also reviews the current literature regarding this complication and discusses the potential causes of dislocation, differential diagnoses for jaw pain following endoscopy, and recommendations for prevention. PMID:27403117

  3. Caecilian jaw-closing mechanics: integrating two muscle systems.

    PubMed

    Kleinteich, Thomas; Haas, Alexander; Summers, Adam P

    2008-12-01

    Caecilians (Lissamphibia: Gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. Using data from high-resolution X-ray radiation computed tomography scans, we modelled the effect of these two muscle groups (mm. levatores mandibulae and m. interhyoideus posterior) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. Measurements of lever arm lengths, muscle fibre orientations and physiological cross-sectional area of cranial muscles were available from three caecilian species: Ichthyophis cf. kohtaoensis; Siphonops annulatus; and Typhlonectes natans. The maximal gape of caecilians is restricted by a critical gape angle above which the mm. levatores mandibulae will open the jaw and destabilize the mandibular joint. The presence of destabilizing forces in the caecilian jaw mechanism may be compensated for by a mandibular joint in that the fossa is wrapped around the condyle to resist dislocation. The caecilian skull is streptostylic; the quadrate-squamosal complex moves with respect to the rest of the skull. This increases the leverage of the jaw-closing muscles. We also demonstrate that the unusual jaw joint requires streptostyly because there is a dorsolateral movement of the quadrate-squamosal complex when the jaw closes. The combination of the two jaw-closing systems results in high bite forces over a wide range of gape angles, an important advantage for generalist feeders such as caecilians. The relative sizes and leverage mechanics of the two closing systems allow one to exert more force when the other has a poor mechanical advantage. This effect is seen in all three species we examined. In the aquatic T. natans, with its less well-roofed skull, there is a larger contribution of the mm. levatores mandibulae to total bite force than in the terrestrial I. cf. kohtaoensis and S. annulatus. PMID

  4. Nasal mask ventilation is better than face mask ventilation in edentulous patients

    PubMed Central

    Kapoor, Mukul Chandra; Rana, Sandeep; Singh, Arvind Kumar; Vishal, Vindhya; Sikdar, Indranil

    2016-01-01

    Background and Aims: Face mask ventilation of the edentulous patient is often difficult as ineffective seating of the standard mask to the face prevents attainment of an adequate air seal. The efficacy of nasal ventilation in edentulous patients has been cited in case reports but has never been investigated. Material and Methods: Consecutive edentulous adult patients scheduled for surgery under general anesthesia with endotracheal intubation, during a 17-month period, were prospectively evaluated. After induction of anesthesia and administration of neuromuscular blocker, lungs were ventilated with a standard anatomical face mask of appropriate size, using a volume controlled anesthesia ventilator with tidal volume set at 10 ml/kg. In case of inadequate ventilation, the mask position was adjusted to achieve best-fit. Inspired and expired tidal volumes were measured. Thereafter, the face mask was replaced by a nasal mask and after achieving best-fit, the inspired and expired tidal volumes were recorded. The difference in expired tidal volumes and airway pressures at best-fit with the use of the two masks and number of patients with inadequate ventilation with use of the masks were statistically analyzed. Results: A total of 79 edentulous patients were recruited for the study. The difference in expiratory tidal volumes with the use of the two masks at best-fit was statistically significant (P = 0.0017). Despite the best-fit mask placement, adequacy of ventilation could not be achieved in 24.1% patients during face mask ventilation, and 12.7% patients during nasal mask ventilation and the difference was statistically significant. Conclusion: Nasal mask ventilation is more efficient than standard face mask ventilation in edentulous patients. PMID:27625477

  5. Morphology and morphometry of the human sublingual glands in mouth floor enlargements of edentulous patients

    PubMed Central

    de SÁ, Josiane Costa Rodrigues; TOLENTINO, Elen de Souza; AZEVEDO-ALANIS, Luciana Reis; IWAKI FILHO, Liogi; LARA, Vanessa Soares; DAMANTE, José Humberto

    2013-01-01

    Asymptomatic mouth floor enlargements may be observed in edentulous patients. These masses, which protrude from the mouth floor, may complicate the fitting of dentures and require surgery. Whether this "entity" may be considered an anatomical variation of the mouth floor or represent specific alterations in the sublingual gland is not known. Objective The aim of this work is to investigate the morphological and morphometric aspects of the sublingual glands of edentulous patients with mouth floor enlargements and compare the glands of these patients with the sublingual glands of human cadavers. Material and Methods Microscopic evaluation was performed on human sublingual glands from edentulous patients with mouth floor enlargements (n=20) and edentulous cadavers (n=20). The patients and cadavers were of similar ages. The data were compared using Mann-Whitney U, Fisher's exact and Student's t tests (p<0.05). Results Acinar atrophy, duct-like structures, mononuclear infiltrates, replacement of parenchyma with fibrous/adipose tissue, mucous extravasation and oncocytosis were similar between the groups (p>0.05). Only the variables "autolysis" and "congested blood vessels" presented statistical difference between groups (p=0.014; p=0.043). The morphometric study revealed that the volume densities of acini, ducts, stroma and adipose tissue were similar between the groups (p>0.05). Conclusion The microscopic characteristics of the sublingual glands in mouth floor enlargements in edentulous patients correspond to characteristics associated with the normal aging process. The glands are not pathological and represent an age-related alteration that occurs with or without the presence of the mouth floor enlargements. PMID:24473720

  6. Nasal mask ventilation is better than face mask ventilation in edentulous patients

    PubMed Central

    Kapoor, Mukul Chandra; Rana, Sandeep; Singh, Arvind Kumar; Vishal, Vindhya; Sikdar, Indranil

    2016-01-01

    Background and Aims: Face mask ventilation of the edentulous patient is often difficult as ineffective seating of the standard mask to the face prevents attainment of an adequate air seal. The efficacy of nasal ventilation in edentulous patients has been cited in case reports but has never been investigated. Material and Methods: Consecutive edentulous adult patients scheduled for surgery under general anesthesia with endotracheal intubation, during a 17-month period, were prospectively evaluated. After induction of anesthesia and administration of neuromuscular blocker, lungs were ventilated with a standard anatomical face mask of appropriate size, using a volume controlled anesthesia ventilator with tidal volume set at 10 ml/kg. In case of inadequate ventilation, the mask position was adjusted to achieve best-fit. Inspired and expired tidal volumes were measured. Thereafter, the face mask was replaced by a nasal mask and after achieving best-fit, the inspired and expired tidal volumes were recorded. The difference in expired tidal volumes and airway pressures at best-fit with the use of the two masks and number of patients with inadequate ventilation with use of the masks were statistically analyzed. Results: A total of 79 edentulous patients were recruited for the study. The difference in expiratory tidal volumes with the use of the two masks at best-fit was statistically significant (P = 0.0017). Despite the best-fit mask placement, adequacy of ventilation could not be achieved in 24.1% patients during face mask ventilation, and 12.7% patients during nasal mask ventilation and the difference was statistically significant. Conclusion: Nasal mask ventilation is more efficient than standard face mask ventilation in edentulous patients.

  7. 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

  8. Flexible piezoelectric energy harvesting from jaw movements

    NASA Astrophysics Data System (ADS)

    Delnavaz, Aidin; Voix, Jérémie

    2014-10-01

    Piezoelectric fiber composites (PFC) represent an interesting subset of smart materials that can function as sensor, actuator and energy converter. Despite their excellent potential for energy harvesting, very few PFC mechanisms have been developed to capture the human body power and convert it into an electric current to power wearable electronic devices. This paper provides a proof of concept for a head-mounted device with a PFC chin strap capable of harvesting energy from jaw movements. An electromechanical model based on the bond graph method is developed to predict the power output of the energy harvesting system. The optimum resistance value of the load and the best stretch ratio in the strap are also determined. A prototype was developed and tested and its performances were compared to the analytical model predictions. The proposed piezoelectric strap mechanism can be added to all types of head-mounted devices to power small-scale electronic devices such as hearing aids, electronic hearing protectors and communication earpieces.

  9. A study of biological chemistry on the nature of jaw cysts. On the maintainance of homoeostasis in jaw cyst fluid.

    PubMed

    Suzuki, M

    1975-06-01

    Jaw cyst lining cells have an active transporting mechanism for Na+ ion and K+ion, a secreting mechanism and a selecting mechanism, and they allow permeation of electrolytes, lipids and protein into cysts. The components within the cysts have a controlling metabolism, and keep the system stable. Tumour wall cells of cystic ameloblastoma have only a passive transporting mechanism for various substances. Their nature differs from that of jaw cyst lining cells.

  10. Flexible thermoplastic denture base materials for aesthetical removable partial denture framework.

    PubMed

    Singh, Kunwarjeet; Aeran, Himanshu; Kumar, Narender; Gupta, Nidhi

    2013-10-01

    Conventional fixed partial dentures, implant supported Fixed Partial Dentures (FDPs) and removable partial dentures are the most common treatment modalities for the aesthetic and functional rehabilitation of partially edentulous patients. Although implants and FDP have certain advantages over removable partial dentures, in some cases, removable partial dentures may be the only choice which is available. Removable cast partial dentures are used as definitive removable prostheses when indicated, but location of clasps may affect aesthetics. So, when patient is concerned about aesthetics, flexible partial dentures which is aesthetically superior to flipper and cast partial dentures, may be considered. But for the success of flexible removable partial denture, proper diagnosis, treatment planning and insertion technique of this prosthesis is very important, which have been thoroughly described in this article. PMID:24298532

  11. Flexible Thermoplastic Denture Base Materials for Aesthetical Removable Partial Denture Framework

    PubMed Central

    Singh, Kunwarjeet; Aeran, Himanshu; Kumar, Narender; Gupta, Nidhi

    2013-01-01

    Conventional fixed partial dentures, implant supported Fixed Partial Dentures (FDPs) and removable partial dentures are the most common treatment modalities for the aesthetic and functional rehabilitation of partially edentulous patients. Although implants and FDP have certain advantages over removable partial dentures, in some cases, removable partial dentures may be the only choice which is available. Removable cast partial dentures are used as definitive removable prostheses when indicated, but location of clasps may affect aesthetics. So, when patient is concerned about aesthetics, flexible partial dentures which is aesthetically superior to flipper and cast partial dentures, may be considered. But for the success of flexible removable partial denture, proper diagnosis, treatment planning and insertion technique of this prosthesis is very important, which have been thoroughly described in this article. PMID:24298532

  12. Telescopic Overdenture and Implant Supported Fixed Partial Denture: A Pragmatic Treatment Approach

    PubMed Central

    Dede, Doğu Ömür; Cenk Durmuşlar, M.; Şahın, Onur; Köroğlu, Ayşegül; İşısağ, Özer

    2015-01-01

    This case report presents a patient who had been rehabilitated with a telescopic overdenture and implant supported fixed partial denture (ISFPD). The treatment process was as follows: (1) fabricating telescopic crowns and overdenture prosthesis for the lower jaw and a temporary complete denture for the upper jaw, (2) using the temporary denture as diagnostic and surgical guide to optimize dental implant placement, and (3) fabricating ISFPD for the upper jaw. Using the patient's existing or temporary denture not only serves as an alternative surgical guide to calibrate the dental implant locations but also helps to finish the restoration at desired dimension, size, and anatomic form. PMID:26106491

  13. Factors associated with osteonecrosis of the jaw among bisphosponate users

    PubMed Central

    Hess, Lisa M; Jeter, Joanne M; Benham-Hutchins, Marge; Alberts, David S.

    2008-01-01

    Background Bisphosphonates are medications that impact bone reformation by inhibiting osteoclast function. Osteonecrosis of the jaw has been reported among patients receiving these medications. It is unclear if the risk factors associated with osteonecrosis of the jaw among cancer patients taking bisphosphonates are also possible risk factors among patients receiving these medications for other indications. Methods A systematic review search strategy was used to identify cases of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer to identify potential contributing factors. Data were analyzed according to previous models to develop a more expanded model that may explain possible mechanisms for the development of osteonecrosis of the jaw among patients without cancer. Results Ninety-nine cases of osteonecrosis of the jaw were identified among patients who were prescribed a bisphosphonate for an indication other than cancer. These cases included 85 osteoporosis patients, 10 patients with Paget’s disease, two patients with rheumatoid arthritis, one patient with diabetes and one patient with maxillary fibrous dysplasia. The mean age was 69.4 years, 87.3% were female, and 87.6% were receiving oral, but not intravenous, bisphosphonates. Of the 63 patients reporting dental care information, 88.9% had a dental procedure prior to the onset of osteonecrosis of the jaw. Of all cases providing medical information, 71% were taking at least one medication that affects bone turnover in addition to the bisphosphonate, and 81.6% reported additional underlying health conditions. Conclusions The case details suggest a multiplicity of factors associated with this condition and provide the foundation for a model outlining the potential mechanism for the development of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer. PMID:18501224

  14. Osteonecrosis of the Jaw Developed in Mice

    PubMed Central

    Park, Sil; Kanayama, Keiichi; Kaur, Kawaljit; Tseng, Han-Ching Helen; Banankhah, Sina; Quje, Davood Talebi; Sayre, James W.; Jewett, Anahid; Nishimura, Ichiro

    2015-01-01

    Osteonecrosis of the jaw (ONJ), an uncommon co-morbidity in patients treated with bisphosphonates (BP), occurs in the segment of jawbone interfacing oral mucosa. This study aimed to investigate a role of oral mucosal barrier γδ T cells in the pathogenesis of ONJ. Female C57Bl/6J (B6) mice received a bolus zoledronate intravenous injection (ZOL, 540 μg/kg), and their maxillary left first molars were extracted 1 week later. ZOL-treated mice (WT ZOL) delayed oral wound healing with patent open wounds 4 weeks after tooth extraction with characteristic oral epithelial hyperplasia. γδ T cells appeared within the tooth extraction site and hyperplastic epithelium in WT ZOL mice. In ZOL-treated γδ T cell null (Tcrd−/− ZOL) mice, the tooth extraction open wound progressively closed; however, histological ONJ-like lesions were identified in 75 and 60% of WT ZOL and Tcrd−/− ZOL mice, respectively. Although the bone exposure phenotype of ONJ was predominantly observed in WT ZOL mice, Tcrd−/− ZOL mice developed the pustule/fistula disease phenotype. We further addressed the role of γδ T cells from human peripheral blood (h-γδ T cells). When co-cultured with ZOL-pretreated human osteoclasts in vitro, h-γδ T cells exhibited rapid expansion and robust IFN-γ secretion. When h-γδ T cells were injected into ZOL-treated immunodeficient (Rag2−/− ZOL) mice, the oral epithelial hyperplasia developed. However, Rag2−/− ZOL mice did not develop osteonecrosis. The results indicate that γδ T cells are unlikely to influence the core osteonecrosis mechanism; however, they may serve as a critical modifier contributing to the different oral mucosal disease variations of ONJ. PMID:26013832

  15. Power spectrum density analysis for the influence of complete denture on the brain function of edentulous patients - pilot study

    PubMed Central

    Perumal, Praveen; Anitha, Kuttae Viswanathan; Reddy, Jetti Ramesh; Muthukumar, Balasubramanium

    2016-01-01

    PURPOSE This pilot study was to find the influence of complete denture on the brain activity and cognitive function of edentulous patients measured through Electroencephalogram (EEG) signals. MATERIALS AND METHODS The study recruited 20 patients aged from 50 to 60 years requiring complete dentures with inclusion and exclusion criteria. The brain function and cognitive function were analyzed with a mental state questionnaire and a 15-minute analysis of power spectral density of EEG alpha waves. The analysis included edentulous phase and post denture insertion adaptive phase, each done before and after chewing. The results obtained were statistically evaluated. RESULTS Power Spectral Density (PSD) values increased from edentulous phase to post denture insertion adaption phase. The data were grouped as edentulous phase before chewing (EEG p1-0.0064), edentulous phase after chewing (EEG p2-0.0073), post denture insertion adaptive phase before chewing (EEG p3-0.0077), and post denture insertion adaptive phase after chewing (EEG p4-0.0096). The acquired values were statistically analyzed using paired t-test, which showed statistically significant results (P<.05). CONCLUSION This pilot study showed functional improvement in brain function of edentulous patients with complete dentures rehabilitation. PMID:27350852

  16. Fossil jawless fish from China foreshadows early jawed vertebrate anatomy.

    PubMed

    Gai, Zhikun; Donoghue, Philip C J; Zhu, Min; Janvier, Philippe; Stampanoni, Marco

    2011-08-17

    Most living vertebrates are jawed vertebrates (gnathostomes), and the living jawless vertebrates (cyclostomes), hagfishes and lampreys, provide scarce information about the profound reorganization of the vertebrate skull during the evolutionary origin of jaws. The extinct bony jawless vertebrates, or 'ostracoderms', are regarded as precursors of jawed vertebrates and provide insight into this formative episode in vertebrate evolution. Here, using synchrotron radiation X-ray tomography, we describe the cranial anatomy of galeaspids, a 435-370-million-year-old 'ostracoderm' group from China and Vietnam. The paired nasal sacs of galeaspids are located anterolaterally in the braincase, and the hypophyseal duct opens anteriorly towards the oral cavity. These three structures (the paired nasal sacs and the hypophyseal duct) were thus already independent of each other, like in gnathostomes and unlike in cyclostomes and osteostracans (another 'ostracoderm' group), and therefore have the condition that current developmental models regard as prerequisites for the development of jaws. This indicates that the reorganization of vertebrate cranial anatomy was not driven deterministically by the evolutionary origin of jaws but occurred stepwise, ultimately allowing the rostral growth of ectomesenchyme that now characterizes gnathostome head development.

  17. Neural crest cell-derived VEGF promotes embryonic jaw extension

    PubMed Central

    Wiszniak, Sophie; Mackenzie, Francesca E.; Anderson, Peter; Kabbara, Samuela; Ruhrberg, Christiana; Schwarz, Quenten

    2015-01-01

    Jaw morphogenesis depends on the growth of Meckel’s cartilage during embryogenesis. However, the cell types and signals that promote chondrocyte proliferation for Meckel’s cartilage growth are poorly defined. Here we show that neural crest cells (NCCs) and their derivatives provide an essential source of the vascular endothelial growth factor (VEGF) to enhance jaw vascularization and stabilize the major mandibular artery. We further show in two independent mouse models that blood vessels promote Meckel’s cartilage extension. Coculture experiments of arterial tissue with NCCs or chondrocytes demonstrated that NCC-derived VEGF promotes blood vessel growth and that blood vessels secrete factors to instruct chondrocyte proliferation. Computed tomography and X-ray scans of patients with hemifacial microsomia also showed that jaw hypoplasia correlates with mandibular artery dysgenesis. We conclude that cranial NCCs and their derivatives provide an essential source of VEGF to support blood vessel growth in the developing jaw, which in turn is essential for normal chondrocyte proliferation, and therefore jaw extension. PMID:25922531

  18. Early and immediate restoration and loading of implants in completely edentulous patients.

    PubMed

    Chiapasco, Matteo

    2004-01-01

    Primary stability and postponement of loading of dental implants for approximately 3 to 6 months have been considered for years the "conditio sine qua non" to allow osseointegration of dental implants. However, in recent years, an increasing number of publications on immediate and early loading of dental implants in completely edentulous patients have appeared in the literature, and high survival rates were generally reported. Nevertheless, much controversy still exists over the reliability of the reported data, frequently because the publications are of insufficient methodologic quality (insufficient follow-up, inadequate sample size, absence of randomization, lack of well-defined exclusion and inclusion criteria, lack of well-defined success criteria, etc). The objective of this study was to review the literature to evaluate the reliability of early and immediate loading of implants placed in the edentulous mandible and maxilla and rehabilitated either with implant-supported overdentures or with implant-supported fixed prostheses.

  19. Type 2 diabetes and edentulism as chronic co-morbid factors affecting Indian elderly: an overview.

    PubMed

    Ladha, Komal; Tiwari, Bhawana

    2013-12-01

    In past 50 years, type 2 diabetes has emerged as one of the major public health problem. India leads the world with the largest number of diabetic patients and has a huge elderly population. The present article discusses the effect of diabetes and edentulism on the overall general health of elderly. The prevalence of type 2 diabetes and edentulism in Indian elderly and their inter-relationship has been discussed. Dentists must provide optimum oral care with special attention towards comprehensive periodontal management and oral hygiene awareness among diabetics to prevent tooth loss. Dental and medical professionals can improve patient management of the oral and overall effects of diabetes by implementing various awareness programs; organizing camps; distributing informative pamphlets and dietary counseling. Dentists can detect undiagnosed cases of diabetes and refer patients to physicians for further evaluation and management. PMID:24431769

  20. Edentulism, Severe Tooth Loss and Lack of Functional Dentition in Elders: A Study in Southern Brazil.

    PubMed

    Ribeiro, Camila Garcez; Cascaes, Andreia Morales; Silva, Alexandre Emídio Ribeiro; Seerig, Lenise Menezes; Nascimento, Gustavo Giacomelli; Demarco, Flávio Fernando

    2016-01-01

    The aim of this study was to estimate self-reported prevalence of edentulism, severe tooth loss and lack of functional dentition in elders, and to identify potential associated factors. A population based cross-sectional study was carried out with 1,451 elders (≥60 years), in Pelotas, RS, Brazil. Crude and adjusted prevalence ratios were estimated using Poisson regressions. The prevalence of edentulism, severe tooth loss and lack of functional dentition was 39.3%, 60.9% and 82.7%, respectively. The factors positively associated with tooth loss in the three-degree severity were sex (females), older individuals, low familial income, low level of schooling and having the last dental visit longer than 24 months ago. The high prevalence of tooth loss in its different degrees of severity and the association with preventable factors highlight the need of programs focused on elders, emphasizing the prevention of tooth loss and need for prosthetic rehabilitation. PMID:27224572

  1. The incidence and morphology of maxillary sinus septa in dentate and edentulous maxillae: a cadaveric study with a brief review of the literature

    PubMed Central

    Wabale, Rajendra Namdeo; Siddiqui, Abu Ubaida; Farooqui, Mujjebuddeen Samsudeen

    2015-01-01

    Objectives The aim of this study is to determine the incidence, location, and orientation of maxillary sinus septa in formalin embalmed cadavers. Materials and Methods The study was conducted on 210 cadaveric heads available in our department. After taking the mid-sagittal section the specimens were opened from the medial aspect and the sinus cavity was explored for the presence of maxillary sinus septa, their anatomical plane, location and dimensions. Results The mean linear distance between maxillary sinus floor and its anatomical ostium was 26.76±5.21 mm and 26.91±4.96 mm on right and left side, respectively. A total of 59 maxillary sinus septa (28.1%) were observed in 210 maxillary specimens. Septae were most common, 33 septa (55.9%), in the middle region (between first and second molar tooth) of the sinus cavity. The maxillary sinus membrane (Schneiderian membrane) adhered tightly to the maxillary sinus and over the septae. Significantly more maxillary sinus septa were observed in edentulous maxillae in comparison to the dentate upper jaw. Conclusion Knowledge of location of maxillary sinus ostium is mandatory for the rhinologist for drainage of secretions in maxillary sinusitis. The morphological details of maxillary sinus septa, particularly their location and anatomical planes, will guide dentists in performance of safe implant surgeries. The maxillary antrum septa of category I and II may complicate the procedure of inversion of bone plate and elevation of sinus membrane during maxillary augmentation surgeries. The category III septa observed in the sagittal plane were embedded by one of the branches of the infraorbital nerve in it, and if accidentally cut will lead to infraorbital nerve palsy in maxillary sinus surgeries. PMID:25741466

  2. Measurement of Mucosal Thickness in Denture-bearing Area of Edentulous Mandible

    PubMed Central

    Dong, Jian; Zhang, Fei-Yu; Wu, Guang-Hui; Zhang, Wei; Yin, Jian

    2015-01-01

    Background: The thickness of the alveolar mucosa influences the probability of the occurrence of denture-induced irritations. Thick denture-supporting tissues offer relief from mucosal tenderness and ulcers; however, the uniformity of the thickness across the entire mandibular alveolar mucosa cannot be accurately determined in edentulous patients. This study aimed to assess the mucosal thickness of the denture-bearing area in the edentulous mandible. Methods: Twenty-seven edentulous patients underwent cone-beam computed tomography scanning, wherein the patients wore a record base to retract soft tissues away from the alveolar mucosa. The measured regions were the central incisor (IC), lateral incisor (IL), canine (Ca), first premolar (P1), second premolar (P2), first molar (M1), and second molar (M2) regions. The thickness was measured in the alveolar ridge crest (T), buccal (B1–B4), and lingual (L1–L4) alveolar ridge mucosa. The average thickness of the mucosa at buccal sides (B) and lingual sides (L) were also assessed. Results: The differences in the mucosal thickness between the left and right sides were not significant. In the Ca–M2 regions, T was the thickest, and L3 was the thinnest of all the measured points in the same regions. L was significantly less than B in posterior regions (P < 0.01). On the other hand, M2 at L4 was thinnest of all the measured regions from Ca to M2 (P < 0.01), and was thicker than IC, IL, P1, and P2 at B2. Conclusions: Since the mucosal thickness of denture-bearing area in the edentulous mandible is not uniform; the tissue surface of the denture base or custom tray should be selectively relieved, which may reduce the risk of denture-induced irritations. PMID:25635429

  3. Edentulism and other variables associated with self-reported health status in Mexican adults

    PubMed Central

    Medina-Solís, Carlo Eduardo; Pontigo-Loyola, América Patricia; Pérez-Campos, Eduardo; Hernández-Cruz, Pedro; Avila-Burgos, Leticia; Mendoza-Rodríguez, Martha; Maupomé, Gerardo

    2014-01-01

    Background To determine if edentulism, controlling for other known factors, is associated with subjective self-report health status (SRH) in Mexican adults. Material/Methods We examined the SRH of 13 966 individuals 35 years and older, using data from the National Survey of Performance Assessment, a cross-sectional study that is part of the technical collaboration between the Ministry of Health of Mexico and the World Health Organization, which used the survey instrument and sampling strategies developed by WHO for the World Health Survey. Sociodemographic, socioeconomic, medical, and behavioral variables were collected using questionnaires. Self-reported health was our dependent variable. Data on edentulism were available from 20 of the 32 Mexican states. A polynomial logistic regression model adjusted for complex sampling was generated. Results In the SRH, 58.2% reported their health status as very good/good, 33.8% said they had a moderate health status, and 8.0% reported that their health was bad/very bad. The association between edentulism and SRH was modified by age and was significant only for bad/very bad SRH. Higher odds of reporting moderate health or poor/very poor health were found in women, people with lower socio-economic status and with physical disabilities, those who were not physically active, or those who were underweight or obese, those who had any chronic disease, and those who used alcohol. Conclusions The association of edentulism with a self-report of a poor health status (poor/very poor) was higher in young people than in adults. The results suggest socioeconomic inequalities in SRH. Inequality was further confirmed among people who had a general health condition or a disability. PMID:24852266

  4. Micro- and macroevolutionary decoupling of cichlid jaws: a test of Liem's key innovation hypothesis.

    PubMed

    Hulsey, C D; García de León, F J; Rodiles-Hernández, R

    2006-10-01

    The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral dual role as a site of both prey capture and prey processing. This functional decoupling that allowed the oral jaws to become devoted solely to prey capture has been hypothesized to have permitted the two sets of cichlid jaws to evolve independently. We tested the hypothesis that oral and pharyngeal jaw mechanics are evolutionarily decoupled both within and among Neotropical Heroine cichlids. In the trophically polymorphic species Herichthys minckleyi, molariforms that exhibit enlarged molarlike pharyngeal jaw teeth were found to have approximately 400% greater lower jaw mass compared to H. minckleyi with the alternative papilliform pharyngeal morphology. However, oral jaw gape, lower jaw velocity ratios, anterior jaw linkage mechanics, and jaw protrusion did not differ between the morphotypes. In 40 other Heroine species, there was a weak correlation between oral jaw mechanics and pharyngeal jaw mass when phylogenetic history was ignored. Yet, after expansion of the cytochrome b phylogeny for Heroines, change in oral jaw mechanics was found to be independent of evolutionary change in pharyngeal jaw mass based on independent contrasts. Evolutionary decoupling of oral and pharyngeal jaw mechanics has likely played a critical role in the unparalleled trophic diversification of cichlid fishes.

  5. Jaw-opening accuracy is not affected by masseter muscle vibration in healthy men.

    PubMed

    Wiesinger, B; Häggman-Henrikson, B; Wänman, A; Lindkvist, M; Hellström, F

    2014-11-01

    There is a functional integration between the jaw and neck regions with head extension-flexion movements during jaw-opening/closing tasks. We recently reported that trigeminal nociceptive input by injection of hypertonic saline into the masseter muscle altered this integrated jaw-neck function during jaw-opening/closing tasks. Thus, in jaw-opening to a predefined position, the head-neck component increased during pain. Previous studies have indicated that muscle spindle stimulation by vibration of the masseter muscle may influence jaw movement amplitudes, but the possible effect on the integrated jaw-neck function is unknown. The aim of this study was to investigate the effect of masseter muscle vibration on jaw-head movements during a continuous jaw-opening/closing task to a target position. Sixteen healthy men performed two trials without vibration (Control) and two trials with bilateral masseter muscle vibration (Vibration). Movements of the mandible and the head were registered with a wireless three-dimensional optoelectronic recording system. Differences in jaw-opening and head movement amplitudes between Control and Vibration, as well as achievement of the predefined jaw-opening target position, were analysed with Wilcoxon's matched pairs test. No significant group effects from vibration were found for jaw or head movement amplitudes, or in the achievement of the target jaw-opening position. A covariation between the jaw and head movement amplitudes was observed. The results imply a high stability for the jaw motor system in a target jaw-opening task and that this task was achieved with the head-neck and jaw working as an integrated system.

  6. Predictable Technique to Register Retruded Contact Position (RCP) Using a Disposable Jaw Relation Recording Device.

    PubMed

    Daher, Tony; Lobel, William A; Massad, Joseph; Ahuja, Swati; Danilov, Zarko Jack

    2015-05-01

    The dental literature presents various definitions and techniques to describe and register centric relation (CR) or centric occlusion (CO). Briefly reviewing the literature in relation to CR, this article proposes the use of the term retruded contact position (RCP), clinically defined as retruded, unstrained, repeatable position and where the mandibular movements start when a Gothic arch tracing is used. With this clinical definition, a technique can be easily selected that meets all the requirements of such position. The article discusses the use of a jaw recorder that is an intraorally graphic recording device that results in a tracing of mandibular movements in one plane, with the apex of the tracing indicating the retruded, unstrained, and repeatable relationship. The intersection of the arcs produced by the right and left working movement form the apex of the Gothic arch tracing. Several clinical situations using the jaw recorder are described. Clinicians can now quickly and accurately record RCP, balance complete, partial, or implant dentures, and orthopedically reposition the mandible. The technique achieves highly reliable and reproducible results.

  7. [Osteoplasty of extensive jaw defects by protected bone regeneration using large pore resorbable implant].

    PubMed

    Blecher, J C; Lemperle, S M; Howaldt, H P

    2000-09-01

    This study was performed to demonstrate a protected bone regeneration method using macroporous resorbable sheets for the treatment of extended lower and upper jaw defects. By applying mechanical protection of bony defects with, e.g. membranes or titanium mesh, soft tissue prolapse as well as pressure on bone transplants which contributes to partial resorption can be avoided. The use of a pressure-resistant, resorbable, macroporous sheet combines the advantage of protected bone regeneration and complete resorption of the implanted sheet. The macroporous structure facilitates capillary ingrowth from the surrounding soft tissue. The sheet is made of 70:30 Poly(L-co-DL)-lactate with thermoplastic character and can be used as a container for autologous spongiosa or other osteoinductive and -conductive bone graft substitutes. In a pilot study, seven patients with lower jaw defects resulting from large cysts or tumor resections, some affecting the continuity of the mandible, were treated with this method. Following a protocol, X-rays were obtained to document the bony regeneration. The positive experience with this pilot study encouraged a multicenter project involving five university hospitals and 50 patients. The application of resorbable sheets in combination with transplantation of mersilized autologous spongiosa is currently being investigated. In future studies, fillings of sheets with osteoconductive and -inductive materials are planned. PMID:11094523

  8. Molecular decay of enamel matrix protein genes in turtles and other edentulous amniotes

    PubMed Central

    2013-01-01

    Background Secondary edentulism (toothlessness) has evolved on multiple occasions in amniotes including several mammalian lineages (pangolins, anteaters, baleen whales), birds, and turtles. All edentulous amniote clades have evolved from ancestors with enamel-capped teeth. Previous studies have documented the molecular decay of tooth-specific genes in edentulous mammals, all of which lost their teeth in the Cenozoic, and birds, which lost their teeth in the Cretaceous. By contrast with mammals and birds, tooth loss in turtles occurred in the Jurassic (201.6-145.5 Ma), providing an extended time window for tooth gene degradation in this clade. The release of the painted turtle and Chinese softshell turtle genomes provides an opportunity to recover the decayed remains of tooth-specific genes in Testudines. Results We queried available genomes of Testudines (Chrysemys picta [painted turtle], Pelodiscus sinensis [Chinese softshell turtle]), Aves (Anas platyrhynchos [duck], Gallus gallus [chicken], Meleagris gallopavo [turkey], Melopsittacus undulatus [budgerigar], Taeniopygia guttata [zebra finch]), and enamelless mammals (Orycteropus afer [aardvark], Choloepus hoffmanni [Hoffmann’s two-toed sloth], Dasypus novemcinctus [nine-banded armadillo]) for remnants of three enamel matrix protein (EMP) genes with putative enamel-specific functions. Remnants of the AMBN and ENAM genes were recovered in Chrysemys and retain their original synteny. Remnants of AMEL were recovered in both testudines, although there are no shared frameshifts. We also show that there are inactivated copies of AMBN, AMEL and ENAM in representatives of divergent avian lineages including Galloanserae, Passeriformes, and Psittaciformes, and that there are shared frameshift mutations in all three genes that predate the basal split in Neognathae. Among enamelless mammals, all three EMP genes exhibit inactivating mutations in Orycteropus and Choloepus. Conclusions Our results highlight the power of

  9. The Sequential Development of Jaw and Lip Control for Speech

    PubMed Central

    Green, Jordan R.; Moore, Christopher A.; Reilly, Kevin J.

    2010-01-01

    Vertical displacements of the upper lip, lower lip, and jaw during speech were recorded for groups of 1-, 2-, and 6-year-olds and adults to examine if control over these articulators develops sequentially. All movement traces were amplitude- and time-normalized. The developmental course of upper lip, lower lip, and jaw control was examined by quantifying age-related changes in the similarity of each articulator's movement patterns to those produced by adult subjects and by same-age peers. In addition, differences in token-to-token stability of articulatory movement were assessed among the different age groups. The experimental findings revealed that 1- and 2-year-old children's jaw movements were significantly more adult-like than their upper and lower lip movements, which were more variable. In contrast, upper and lower lip movement patterns became more adult-like with maturation. These findings suggest that the earliest stages of speech motor development are constrained by the nonuniform development of articulatory control, with the jaw preceding the lips. The observed developmental patterns suggest that the properties of the oral motor control system significantly influence the pattern of speech sound acquisition. PMID:14748639

  10. Tongue-jaw kinematic correlates of /s/ spectra

    NASA Astrophysics Data System (ADS)

    Dembowski, James S.; Crumb, Richard K.

    2001-05-01

    Frequencies of spectral peaks for fricatives are determined by the size of the resonating cavity anterior to the place of articulatory constriction in the upper vocal tract. For /s/, this cavity size may be altered through anterior-posterior (a-p) movements of the tongue blade forming the constriction, changes of jaw height, and degree of lip protrusion. With respect to intensity, modeling studies suggest that intensity of fricative spectral peaks may be related to degree of articulatory constriction. These spectral-kinematic relationships have been little studied in natural speech. This study used data from the University of Wisconsin X-Ray Microbeam Database to examine the relationship between spectral peaks and movements of the tongue and jaw in the /s/ productions of one normal speaker. Results showed no relationship between a-p tongue position and frequency of spectral peaks. However, a significant inverse correlation related peak between frequency and jaw opening. Thus, for this speaker jaw height appeared a more important determinant of spectral variability for /s/ than tongue position. Additional results showed a significant relationship between peak intensity and distance of the tongue blade from the palate. These natural speech data will be discussed with respect to models and theories of fricative production.

  11. Embryology and Anatomy of the Jaw and Dentition.

    PubMed

    Zohrabian, Vahe M; Poon, Colin S; Abrahams, James J

    2015-10-01

    Radiologists should possess working knowledge of the embryological development and anatomy of the jaw and dentition in order to aid in the diagnosis of both simple and complex disorders that affect them. Here, we review the elaborate process of odontogenesis, as well as describe in detail the anatomy of a tooth and its surrounding structures.

  12. Jaw-Phonatory Coordination in Chronic Developmental Stuttering

    ERIC Educational Resources Information Center

    Loucks, Torrey M. J.; De Nil, Luc F.; Sasisekaran, Jayanthi

    2007-01-01

    A deficiency in sensorimotor integration in a person who stutters may be a factor in the pathophysiology of developmental stuttering. To test oral sensorimotor function in adults who stutter, we used a task that requires the coordination of a jaw-opening movement with phonation onset. The task was adapted from previous limb coordination studies,…

  13. DETAIL VIEW OF ORE BINS AND JAW CRUSHER WITH SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF ORE BINS AND JAW CRUSHER WITH SIX FOOT SCALE, LOOKING NORTHWEST FROM NEARBY THE ENGINE. SEE CA-292-18 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

  14. DETAIL VIEW OF ORE BINS AND JAW CRUSHER WITH SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF ORE BINS AND JAW CRUSHER WITH SIX FOOT SCALE, LOOKING NORTHWEST FROM NEARBY THE ENGINE. SEE CA-292-9 FOR IDENTICAL B&W NEGATIVE. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

  15. A dynamic model of jaw and hyoid biomechanics during chewing.

    PubMed

    Hannam, A G; Stavness, I; Lloyd, J E; Fels, S

    2008-01-01

    Our understanding of human jaw biomechanics has been enhanced by computational modelling, but comparatively few studies have addressed the dynamics of chewing. Consequently, ambiguities remain regarding predicted jaw-gapes and forces on the mandibular condyles. Here, we used a new platform to simulate unilateral chewing. The model, based on a previous study, included curvilinear articular guidance, a mobile hyoid apparatus, and a compressible food bolus. Muscles were represented by Hill-type actuators with drive profiles tuned to produce target jaw and hyoid movements. The cycle duration was 732 ms. At maximum gape, the lower incisor-point was 20.1mm down, 5.8mm posterior, and 2.3mm lateral to its initial, tooth-contact position. Its maximum laterodeviation to the working-side during closing was 6.1mm, at which time the bolus was struck. The hyoid's movement, completed by the end of jaw-opening, was 3.4mm upward and 1.6mm forward. The mandibular condyles moved asymmetrically. Their compressive loads were low during opening, slightly higher on the working-side at bolus-collapse, and highest bilaterally when the teeth contacted. The model's movements and the directions of its condylar forces were consistent with experimental observations, resolving seeming discordances in previous simulations. Its inclusion of hyoid dynamics is a step towards modelling mastication.

  16. 15. NORTH ELEVATION OF UPPER ORE BIN, CHUTE, AND JAW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. NORTH ELEVATION OF UPPER ORE BIN, CHUTE, AND JAW CRUSHER, LOOKING SOUTH FROM END OF CONVEYOR PLATFORM. NOTICE THE THREE ORE BIN CONTROL DOORS, CORRESPONDING TO SEPARATE COMPARTMENTS OF THE BIN. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

  17. 12. CLOSEUP OF THE CURRENT TRASH RAKELIFTING MECHANISM (CALLED 'JAWS' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP OF THE CURRENT TRASH RAKE-LIFTING MECHANISM (CALLED 'JAWS' BY THE PRESENT OPERATORS), LOOKING WEST. THIS EQUIPMENT WAS REMOVED IN AUTUMN OF 1996. - Washington Water Power Company Post Falls Power Plant, Middle Channel Powerhouse & Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  18. Identification and characterization of gelatinases/type IV collagenases in jaw cysts.

    PubMed

    Teronen, O; Salo, T; Konttinen, Y T; Rifkin, B; Vernillo, A; Ramamurthy, N S; Kjeldsen, L; Borregaard, N; Hietanen, J; Sorsa, T

    1995-02-01

    The molecular mechanisms of jaw cyst expansion probably involve interactions of matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs). In this study, molecular species of gelatinases present in neutral salt extracts of cyst walls and cyst fluids were characterized by functional activity measurements (type I gelatin and alpha-casein zymography) and immunologically (Western-blotting). The effects of various protein thiol-group or cysteine-switch reactants involved in the activation of collagenases were studied on cyst gelatinases and a gelatinases purified from human gingival fibroblasts (72 kD MMP-2), gingival keratinocytes (92 kD MMP-9) and polymorphonuclear neutrophilic leukocytes (92 kD MMP-9). Western-blotting revealed the presence of both 92 kD (MMP-9) and 72 kD (MMP-2) gelatinases in cyst wall extracts and cyst fluids. Western-blot studies further suggested that jaw cyst gelatinases were only in part complexed with and thus inhibited by TIMP-1 or TIMP-2, suggesting that both MMP-9 and MMP-2 may participate in cyst expansion. MMP-2 was also partially fragmented to a 68 kD form and additional lower molecular weight proteinases (< 60 kD) were detected by alpha-casein zymography and by Western-blotting, suggesting proteolytic fragmentation. MMP-9 was at least partially activated by all protein-thiol group reactants and rather resistant to oxidative inhibition by hypochlorite (NaOCl); in contrast, MMP-2 was activated by APMA but not at all by gold thioglucose (GTG) and was clearly inactivated by hypochlorite (NaOCl).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Dynamic Jaws and Dynamic Couch in Helical Tomotherapy

    SciTech Connect

    Sterzing, Florian; Uhl, Matthias; Hauswald, Henrik; Schubert, Kai; Sroka-Perez, Gabriele; Chen Yu; Lu Weiguo; Mackie, Rock; Debus, Juergen; Herfarth, Klaus; Oliveira, Gustavo

    2010-03-15

    Purpose: To investigate the next generation of helical tomotherapy delivery with dynamic jaw and dynamic couch movements. Methods and Materials: The new technique of dynamic jaw and dynamic couch movements is described, and a comparative planning study is performed. Ten nasopharyngeal cancer patients with skull base infiltration were chosen for this comparison of longitudinal dose profiles using regular tomotherapy delivery, running-start-stop treatment, and dynamic jaw and dynamic couch delivery. A multifocal simultaneous integrated boost concept was used (70.4Gy to the primary tumor and involved lymph nodes; 57.4Gy to the bilateral cervical lymphatic drainage pathways, 32 fractions). Target coverage, conformity, homogeneity, sparing of organs at risk, integral dose, and radiation delivery time were evaluated. Results: Mean parotid dose for all different deliveries was between 24.8 and 26.1Gy, without significant differences. The mean integral dose was lowered by 6.3% by using the dynamic technique, in comparison with a 2.5-cm-field width for regular delivery and 16.7% with 5-cm-field width for regular delivery. Dynamic jaw and couch movements reduced the calculated radiation time by 66% of the time required with regular 2.5-cm-field width delivery (199 sec vs. 595 sec, p < 0.001). Conclusions: The current delivery mode of helical tomotherapy produces dose distributions with conformal avoidance of parotid glands, brain stem, and spinal cord. The new technology with dynamic jaw and couch movements improves the plan quality by reducing the dose penumbra and thereby reducing the integral dose. In addition, radiation time is reduced by 66% of the regular delivery time.

  20. Apodemes associated with limbs support serial homology of claws and jaws in Onychophora (velvet worms).

    PubMed

    de Sena Oliveira, Ivo; Mayer, Georg

    2013-10-01

    Although the onychophoran jaw blades are believed to be derivatives of foot claws, serial homology of these structures has not been demonstrated. To shed light on the evolutionary origin of the onychophoran jaws, we searched for morphological landmarks and compared the internal and external anatomy of jaws and distal leg portions in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Our data revealed hitherto unknown structures associated with the onychophoran limbs, such as a soft diastemal membrane separating the anterior and posterior portions of the inner jaw blade (present only in Peripatidae), apodemes associated with feet, an eversible dorsal sac at the basis of each foot claw, and a specific arrangement of musculature associated with the sclerotised claws, jaws and their apodemes. Specific correspondences in structure and position of apodemes support serial homology of claws and jaws, suggesting that the onychophoran jaw evolved from the distal portion rather than the entire limb in the last common ancestor of Onychophora.

  1. An EPID based method for efficient and precise asymmetric jaw alignment quality assurance

    SciTech Connect

    Clews, Luke; Greer, Peter B.

    2009-12-15

    Purpose: The aim of this work was to investigate the use of amorphous silicon electronic portal imaging devices (EPIDs) for regular quality assurance of linear accelerator asymmetric jaw junctioning. Methods: The method uses the beam central axis position on the EPID measured to subpixel accuracy found from two EPID images with 180 degree sign opposing collimator angles. Individual zero jaw position (''half-beam blocked'') images are then acquired and the jaw position precisely determined for each using penumbra interpolation. The accuracy of determining jaw position with the EPID method was measured by translating a block (simulating a jaw) by known distances, using a translation stage, and then measuring each translation distance with the EPID. To establish the utility of EPID based junction dose measurements, radiographic film measurements of junction dose maxima/minima as a function of jaw gap/overlap were made and compared to EPID measurements. Using the method, the long-term stability of zero jaw positioning was assessed for four linear accelerators over a 1-1.5 yr time period. The stability at nonzero gantry angles was assessed over a shorter time period. Results: The accuracy of determining jaw translations with the method was within 0.14 mm found using the translation stage [standard deviation (SD) of 0.037 mm]. The junction doses measured with the EPID were different from film due to the nonwater equivalent EPID scattering properties and hence different penumbra profile. The doses were approximately linear with gap or overlap, and a correction factor was derived to convert EPID measured junction dose to film measured equivalent. Over a 1 yr period, the zero jaw positions at gantry zero position were highly reproducible with an average SD of 0.07 mm for the 16 collimator jaws examined. However, the average jaw positions ranged from -0.7 to 0.9 mm relative to central axis for the different jaws. The zero jaw position was also reproducible at gantry 90

  2. Integrated jaw and neck function in man. Studies of mandibular and head-neck movements during jaw opening-closing tasks.

    PubMed

    Zafar, H

    2000-01-01

    This investigation was undertaken to test the hypothesis of a functional relationship between the human temporomandibular and craniocervical regions. Mandibular and head-neck movements were simultaneously recorded in healthy young adults using a wireless optoelectronic system for three dimensional movement recording. The subjects were seated in an upright position without head support and were instructed to perform maximal jaw opening-closing movements at fast and slow speed. As a basis, a study was undertaken to develop a method for recording and analysis of mandibular and head-neck movements during natural jaw function. A consistent finding was parallel and coordinated head-neck movements during both fast and slow jaw opening-closing movements. The head in general started to move simultaneously with or before the mandible at the initiation of jaw opening. Most often, the head attained maximum velocity after the mandible. A high degree of spatiotemporal consistency of mandibular and head-neck movement trajectories was found in successive recording sessions. The head movement amplitude and the temporal coordination between mandibular and head-neck movements were speed related but not the movement trajectory patterns. Examination of individuals suffering from temporomandibular disorders and whiplash associated disorders (WAD) showed, compared with healthy subjects, smaller amplitudes, a diverse pattern of temporal coordination but a similar high degree of spatiotemporal consistency for mandibular and head-neck movements. In conclusion, the results suggest the following: A functional linkage exists between the human temporomandibular and craniocervical regions. Head movements are an integral part of natural jaw opening-closing. "Functional jaw movements" comprise concomitant mandibular and head-neck movements which involve the temporomandibular, the atlanto-occipital and the cervical spine joints, caused by jointly activated jaw and neck muscles. Jaw and neck muscle

  3. The origin and early phylogenetic history of jawed vertebrates

    PubMed Central

    Brazeau, Martin D.; Friedman, Matt

    2015-01-01

    The focus of study for nearly two centuries1, fossils of early gnathostomes—or jawed vertebrates—yield key clues about the evolutionary assembly of the bodyplan common to the group, as well the divergence of the two living gnathostome lineages: the cartilaginous and bony fishes2,3. A series of remarkable new palaeontological discoveries4-10, analytical advances and innovative reinterpretations of old fossils11-14 have fundamentally altered a decades-old consensus on the relationships of extinct gnathostomes15,16, delivering a new evolutionary framework3,6,10-14 for exploring major questions which remain unanswered, including the origin of jaws17-19. PMID:25903631

  4. The earliest herbivorous marine reptile and its remarkable jaw apparatus.

    PubMed

    Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C

    2016-05-01

    Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles.

  5. The earliest herbivorous marine reptile and its remarkable jaw apparatus

    PubMed Central

    Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C.

    2016-01-01

    Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles. PMID:27386529

  6. Jaw, blink and corneal reflex latencies in multiple sclerosis.

    PubMed Central

    Sanders, E A; Ongerboer de Visser, B W; Barendswaard, E C; Arts, R J

    1985-01-01

    Jaw, blink and corneal reflexes, which all involve the trigeminal system, were recorded in 54 patients with multiple sclerosis; thirty-seven of these patients were classified as having definite multiple sclerosis and 17 as indefinite multiple sclerosis, according to Schumacher's criteria. The jaw reflex was abnormal less frequently than either of the other two reflexes, but in four cases it was the only abnormal reflex found. Testing a combination of two or three trigeminal reflexes did not yield a higher incidence of abnormalities than testing the blink or corneal reflex alone. Nine patients showed abnormal reflexes which were unexpected on the basis of clinical symptoms. The combined recordings demonstrate at least one abnormal reflex in 74% of the patients. The various types of reflex abnormalities reflect major damage to different parts of the trigeminal system and may therefore make an important contribution to the diagnosis of multiple sclerosis. PMID:4087004

  7. Multiple Compond Odontomas in the Jaws: A Rare Case Report

    PubMed Central

    Sahni, Priya; Pereira, Treville; Zingade, Jyoti

    2015-01-01

    Odontomas are tumours of odontogenic origin. In these tumours both the epithelial and mesenchymal cells undergo differentiation to form enamel and dentin with variable amounts of cementum and pulp tissue. The odontomas represent a hamartoma rather than a neoplasm. When the enamel and dentin are laid down in an organized manner it is termed as a compound odontoma wherein the tumour forms a collection of small structures resembling teeth. On the other hand, an irregular mass with no similarity to teeth is termed as a complex odontoma. There are cases of extensive and multiple compound odontomas which have been identified in either of the jaws. The present case is rare with multiple compound odontomas involving both the jaws of 45-year-old male patient. A review of seven such cases reported so far has been presented. PMID:26816995

  8. Multiple Compond Odontomas in the Jaws: A Rare Case Report.

    PubMed

    Gujjar, Pavan Kumar; Sahni, Priya; Pereira, Treville; Zingade, Jyoti

    2015-12-01

    Odontomas are tumours of odontogenic origin. In these tumours both the epithelial and mesenchymal cells undergo differentiation to form enamel and dentin with variable amounts of cementum and pulp tissue. The odontomas represent a hamartoma rather than a neoplasm. When the enamel and dentin are laid down in an organized manner it is termed as a compound odontoma wherein the tumour forms a collection of small structures resembling teeth. On the other hand, an irregular mass with no similarity to teeth is termed as a complex odontoma. There are cases of extensive and multiple compound odontomas which have been identified in either of the jaws. The present case is rare with multiple compound odontomas involving both the jaws of 45-year-old male patient. A review of seven such cases reported so far has been presented.

  9. Neural crest patterning and the evolution of the jaw

    PubMed Central

    B. KIMMEL, CHARLES; T. MILLER, CRAIG; J. KEYNES, ROGER

    2001-01-01

    Here we present ideas connecting the behaviour of the cranial neural crest during development with the venerable, perhaps incorrect, view that gill-supporting cartilages of an ancient agnathan evolved into the skeleton of an early gnathostome's jaw. We discuss the pattern of migration of the cranial neural crest ectomesenchyme in zebrafish, along with the subsequent arrangement of postmigratory crest and head mesoderm in the nascent pharyngeal segments (branchiomeres), in diverse gnathostomes and in lampreys. These characteristics provide for a plausible von Baerian explanation for the problematic inside-outside change in topology of the gills and their supports between these 2 major groups of vertebrates. We consider it likely that the jaw supports did indeed arise from branchiomeric cartilages. PMID:11523812

  10. The relationship of denosumab pharmacology and osteonecrosis of the jaws.

    PubMed

    Malan, John; Ettinger, Kyle; Naumann, Erich; Beirne, O Ross

    2012-12-01

    Denosumab is a new bone antiresorptive agent that has received approval by the Food and Drug Administration for use in patients with osteoporosis and metastatic cancer to the bones. Like the bisphosponates that are used as antiresorptive medications, denosumab has been associated with osteonecrosis of the jaws (ONJ). However, because the pharmacodynamics and pharmacokinetics of denosumab differ from that of the bisphosphonates, ONJ related to denosumab may resolve more rapidly with a drug holiday than bisphosphonate-related osteonecrosis of the jaws (BRONJ). This paper describes the management of a patient who developed ONJ while receiving denosumab, reviews the incidence of ONJ associated with denosumab, and compares the pharmacology of denosumab and the bisphosphonates. Because the effects of denosumab on bone turnover are more rapidly reversible than the effects of the bisphosphonates, ONJ related to denosumab may resolve more quickly with a drug holiday than BRONJ. PMID:23159111

  11. Sunitinib related osteonecrosis of jaw: a case report.

    PubMed

    Fleissig, Yoram; Regev, Eran; Lehman, Hadas

    2012-03-01

    A 58-year-old woman presented to the Oral and Maxillofacial Surgery Clinic experiencing severe limited mouth opening and exposed bone in the socket of the right mandibular third molar 8 months following the extraction of the tooth. The patient had been treated during the year before her presentation with sunitinib, an antiangiogenic drug, for renal cell carcinoma. The clinical, radiographic, and histologic picture of a chronic nonhealing extraction socket was consistent with osteonecrosis of the jaw (ONJ), although she had never been treated with bisphosphonates or corticosteroids. The treatment with sunitinib was discontinued and the patient was treated with antibiotics and physiotherapy for 12 weeks with complete recovery. Sunitinib may cause osteonecrosis of the jaw after oral surgical interventions with no previous exposure to bisphosphonates. The pathogenesis may be related to its antiangiogenic mechanism and impaired wound healing. Full recovery may require long-term cessation of the insulting drug combined with prolonged antibiotic treatment. PMID:22676833

  12. The earliest herbivorous marine reptile and its remarkable jaw apparatus.

    PubMed

    Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C

    2016-05-01

    Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles. PMID:27386529

  13. Medication Management of Jaw Lesions for Dental Patients.

    PubMed

    Ogle, Orrett E; Santosh, Arvind Babu Rajendra

    2016-04-01

    Most pathologic lesions of the jaws or of oral mucosa are treated successfully by surgical interventions. For treatment of the central giant cell lesion, aneurysmal bone cysts, histiocytosis of the mandible, hemangioma, odontogenic keratocyst, Paget disease, oral submucous fibrosis, and oral lichen planus, medical management consisting of intralesional injections, sclerosing agents, and systemic bisphosphonates is as successful as surgical procedures with fewer complications. Pharmacology of agents used and protocols are presented. PMID:27040297

  14. EVALUATION OF EDENTULISM, PROSTHETIC STATUS AND PROSTHODONTICS TREATMENT NEEDS AMONG THE ADULT POPULATION OF GEORGIA.

    PubMed

    Makhviladze, G; Tsitaishvili, L; Kalandadze, M; Margvelashvili, V

    2016-04-01

    The aim of the present study is to identify the level of edentulism among the adult population of Georgia, to assess the prosthodontics status and normative needs for prosthetic treatment. Cluster- stratified method was used for sampling. Overall, 2370 adults including 1289 women and 1081 men and four age groups I - 20-34, II - 35-44, III - 45-64, IV - 65-74 in nine regions of Georgia and the capital, Tbilisi, were examined. The loss of teeth due to caries or periodontitis was observed to differing extents throughout the population. One (8.3%) or more bridges (7.6%) and removable dentures (3.2-4.7%) were more frequently observed than implants (0.1%). Metal-ceramic (12.4%) and metal crowns (6.3%) were more commonly detected than zirconia ceramic crowns (0.1%). Statistical analysis of the data demonstrates a rather high normative prosthetic need of implants and bridges and less needs for removable dentures among the population due to less severity of periodontitis and not too high values of missing teeth due to caries (despite the high caries prevalence (99%) throughout the Georgian population). Edentulism is a public problem in Georgia and needs serious attention from government or healthcare centers to prevent the complications . PMID:27249431

  15. Rehabilitation with implant-supported overdentures in total edentulous patients: A review

    PubMed Central

    Segura-Andrés, Gustavo; Faus-López, Joan; Agustín-Panadero, Rubén

    2013-01-01

    Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on the mentioned subject from 1986 to 2011. As a searching strategy, we used the following words: implant-supported overdentures, attachment systems, Locator attachment, cantilever, fixed prosthesis. Results and conclusions: Implant-supported overdentures constitute an accurate and predictable treatment option and achieve a higher patients’ satisfaction. This type of treatment constitutes a cheaper treatment than fixed prostheses and in some patients, with loss of lip support or with an interoclusal space larger than 15 mm, the choice of implant-supported overdentures seems to prevent future aesthetic or phonetic problems. Key words:Overdentures, implant occlusion, implant rehabilitation, total edentulous rehabilitation, fixed prosthesis. PMID:24455093

  16. Nitric Oxide Concentration and Other Salivary Changes after Insertion of New Complete Dentures in Edentulous Subjects

    PubMed Central

    Breseghelo, Maria de Lourdes; Guillo, Lídia Andreu; Nogueira, Túlio Eduardo

    2016-01-01

    Objective. To assess changes in levels of salivary nitric oxide (NO) after insertion of new complete dentures and its association with clinical and salivary parameters. Methods. Nineteen fully edentulous subjects were included, mean age 64.4. Unstimulated whole saliva was collected before and after insertion of the dentures, at follow-up visits, and after 12 months. The concentration of the final stable NO product (nitrite) was measured by a colorimetric assay based on the Griess reaction. Clinical parameters were assessed during all clinical visits. Results. Functional adaptation to the dentures progressively improved, with no complaints at the long-term follow-up. NO concentration was not influenced by the level of functional adaptation, presence of injuries to the mucosa, salivary flow, and saliva viscosity. Pairwise comparison showed a reduction in NO concentration at the first follow-up compared to baseline values but differences were not statistically significant. Significant differences were observed in NO concentrations at the long-term follow-up when compared to the first (p = 0.024) and second (p = 0.027) visits. Conclusion. NO concentration reduced after denture insertion and returned to baseline levels in the long-term follow-up. This appears to be an autonomic response of the body and provides valuable complementary information for the management of the edentulous patient. PMID:27034674

  17. Palatal Rugae Patterns in Edentulous Cases, Are They A Reliable Forensic Marker?

    PubMed Central

    Poojya, R.; Shruthi, C. S.; Rajashekar, Vaishali Mysore; Kaimal, Aswathy

    2015-01-01

    One of the main objectives of the forensic sciences is establishing a person’s identity which can be a very complex process. The analysis of the teeth, fingerprints and DNA evaluation are probably the most used techniques allowing fast and secure identification processes. Palatal rugae or transverse palatine folds are asymmetrical and irregular elevations of the mucosa located in the anterior third of the palate and are permanent, prominent and unique for individuals and thus can be used as identification for forensic purposes widely in edentulous patients wherein no teeth are present in the oral cavity. In forensic odontology dentists play a prime role in supporting legal and criminal issues. Palatoscopy or palatal rugoscopy is the name given to the study of palatal rugae in order to ascertain a person’s identity. Studies have demonstrated that no two individual rugae patterns are alike in their configuration and the characteristic rugae pattern of the palate does not change as a result of growth. Hence this article reviews the significance of palatal rugae patterns in edentulous cases as a reliable forensic marker. PMID:26508904

  18. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide.

    PubMed

    Mortazavi, Hamed; Baharvand, Maryam

    2016-09-01

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as "jaw lesion", "jaw disease", "impacted tooth", and "unerupted tooth". More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs. PMID:27672610

  19. Computer Simulation Methods for Crushing Process in an Jaw Crusher

    NASA Astrophysics Data System (ADS)

    Il'ich Beloglazov, Ilia; Andreevich Ikonnikov, Dmitrii

    2016-08-01

    One of the trends at modern mining enterprises is the application of combined systems for extraction and transportation of the rock mass. Given technology involves the use the conveyor lines as a continuous link of combined technology. The application of a conveyor transport provides significant reduction of costs for energy resources, increase in labor productivity and process automation. However, the use of a conveyor transport provides for certain requirements for the quality of transported material. The maximum size of the rock mass pieces is one of the basic parameters for it. The crushing plants applies as a coarse crushing followed by crushing the material to the maximum size of piece which possible to use for conveyor transport. It is often represented by jaw crushers. Modelling of crushing process in jaw crushers allows to maximally optimize workflow and increase efficiency of the equipment at the further transportation and processing of rocks. We studied the interaction between walls of the jaw crusher and bulk material by using discrete element method (DEM) in this paper. The article examines the process of modeling by stages. It includes design of the crusher construction in solid and surface modeling system. Modelling of the crushing process based on the experimental data received via the crushing unit BOYD. The process of destruction and particle size distribution in the study was done. Analysis of research results shows a comparability of actual experiment and modeling process.

  20. Sella size and jaw bases - Is there a correlation???

    PubMed Central

    Neha; Mogra, Subraya; Shetty, Vorvady Surendra; Shetty, Siddarth

    2016-01-01

    Introduction: Sella turcica is an important cephalometric structure and attempts have been made in the past to correlate its dimensions to the malocclusion. However, no study has so far compared the size of sella to the jaw bases that determine the type of malocclusion. The present study was undertaken to find out any such correlation if it exists. Materials and Methods: Lateral cephalograms of 110 adults consisting of 40 Class I, 40 Class II, and 30 Class III patients were assessed for the measurement of sella length, width, height, and area. The maxillary length, mandibular ramus height, and body length were also measured. The sella dimensions were compared among three malocclusion types by one-way ANOVA. Pearson correlation was calculated between the jaw size and sella dimensions. Furthermore, the ratio of jaw base lengths and sella area were calculated. Results and Conclusion: Mean sella length, width and area were found to be greatest in Class III, followed by Class I and least in Class II though the results were not statistically significant. 3 out of 4 measured dimensions of sella, correlated significantly with mandibular ramus and body length each. However, only one dimension of sella showed significant correlation with maxilla. The mandibular ramus and body length show a nearly constant ratio to sella area (0.83–0.85, 0.64–0.65, respectively) in all the three malocclusions. Thus, mandible has a definite and better correlation to the size of sella turcica. PMID:27041903

  1. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

    PubMed Central

    Mortazavi, Hamed

    2016-01-01

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as "jaw lesion", "jaw disease", "impacted tooth", and "unerupted tooth". More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs.

  2. Contingent negative variation elicited before jaw and tongue movements.

    PubMed

    Yoshida, K; Iizuka, T

    2005-12-01

    Contingent negative variation (CNV) is a negative brain potential occurring between two successive stimuli when the first stimulus is a warning and the second stimulus requires a motor response. The CNV is interpreted as an expression of the cognitive processes in preparation for a response directed to a purpose. Using 19 electrodes we recorded CNVs for mouth opening, closing and lateral movements, tongue protrusion and hand extension in 10 healthy subjects. The aim of the study was to examine the motor control mechanism underlying jaw and tongue movements in a cognitive paradigm. The first stimulus (S1) served as a preparatory warning signal for the imperative stimulus (S2) 2 s after the S1. The subject performed the experimental tasks after the S2. The grand average CNVs for jaw and tongue movements showed a bilaterally widespread negativity with the maximum in the vertex region (Cz). The early CNV was identified about 400 ms after the S1 and its amplitude was highest at the midline-frontal area. The late CNV started approximately 1000 ms after the S1 with the maximum at Cz. The mean amplitude was significantly lower for hand extension than for the other tasks, and significantly higher for lateral movement than for mouth closing, suggesting that the CNV amplitude can be affected by the complexity of the task. The CNV recording may provide a means to study the neuronal activity necessary for the sensorimotor integration of jaw and tongue movements.

  3. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

    PubMed Central

    Mortazavi, Hamed

    2016-01-01

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as "jaw lesion", "jaw disease", "impacted tooth", and "unerupted tooth". More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs. PMID:27672610

  4. Electrophysiological analysis of rhythmic jaw movements in the freely moving mouse.

    PubMed

    Kobayashi, Masayuki; Masuda, Yuji; Fujimoto, Yoshiyuki; Matsuya, Tokuzo; Yamamura, Kensuke; Yamada, Yoshiaki; Maeda, Norihiko; Morimoto, Toshifumi

    2002-03-01

    Although rhythmic jaw movement in feeding has been studied in mammals, such as rats, rabbits and monkeys, the cellular and molecular mechanisms underlying it are not well understood. Transgenic and gene-targeting technologies enable direct control of the genetic makeup of the mouse, and have led to the development of a new category of reagents that have the potential to elucidate the cellular and molecular mechanisms of neural networks. The present study attempts to characterize rhythmic jaw movements in the mouse and to demonstrate its relevance to rhythmic jaw movements found in higher mammals using newly developed jaw-tracking systems and electromyograms of the masticatory muscles. The masticatory sequence of the mouse during feeding was classified into two stages, incision and chewing. Small and rapid (8 Hz) open-close jaw movements were observed during incision, while large and slow (5 Hz) open-close jaw movements were observed during chewing. Integrated electromyograms of the masseteric and digastric muscles were larger during chewing than those observed during incision. Licking behavior was associated with regular (8 Hz), small open-close jaw movements with smaller masseteric activity than those observed during mastication. Grooming showed variable patterns of jaw movement and electromyograms depending on the grooming site. These results suggest that there are neuronal mechanisms producing different frequencies of rhythmic jaw movements in the mouse, and we conclude that the mouse is useful for understanding rhythmic jaw movements in higher mammals.

  5. Serial extraction protocol for partial arches in implant dentistry: principles and clinical methodology.

    PubMed

    Cavallaro, John S; Greenstein, Gary; Greenstein, Ben

    2010-01-01

    Serial extraction protocol (SEP) is a clinical technique that facilitates using natural tooth abutments to support a fixed interim resin prosthesis, while inserting a sufficient number of implants to retain a definitive fixed prosthesis. A Class 1 protocol allows all necessary implants to be placed during one surgical appointment, while a Class 2 protocol requires two or more rounds of implant installation to achieve sufficient support for a definitive fixed prosthesis. The SEP methodology can be used to restore full and partially edentulous dentitions. This article addresses rehabilitation of partial arches using an SEP protocol.

  6. Developmental evidence for serial homology of the vertebrate jaw and gill arch skeleton.

    PubMed

    Gillis, J Andrew; Modrell, Melinda S; Baker, Clare V H

    2013-01-01

    Gegenbaur's classical hypothesis of jaw-gill arch serial homology is widely cited, but remains unsupported by either palaeontological evidence (for example, a series of fossils reflecting the stepwise transformation of a gill arch into a jaw) or developmental genetic data (for example, shared molecular mechanisms underlying segment identity in the mandibular, hyoid and gill arch endoskeletons). Here we show that nested expression of Dlx genes--the 'Dlx code' that specifies upper and lower jaw identity in mammals and teleosts--is a primitive feature of the mandibular, hyoid and gill arches of jawed vertebrates. Using fate-mapping techniques, we demonstrate that the principal dorsal and ventral endoskeletal segments of the jaw, hyoid and gill arches of the skate Leucoraja erinacea derive from molecularly equivalent mesenchymal domains of combinatorial Dlx gene expression. Our data suggest that vertebrate jaw, hyoid and gill arch cartilages are serially homologous, and were primitively patterned dorsoventrally by a common Dlx blueprint.

  7. Function of a key morphological innovation: fusion of the cichlid pharyngeal jaw

    PubMed Central

    Darrin Hulsey, C

    2005-01-01

    The pharyngeal jaw of cichlids may represent a key innovation that facilitated their unparalleled trophic divergence. In cichlids, ‘fusion’ of the lower pharyngeal jaw (LPJ) results from suturing between the two lower ceratobranchials. To examine, what novel abilities a more extensively fused pharyngeal jaw may confer, the function of LPJ suturing was examined in Heroine cichlids. Greater LPJ suturing, pharyngeal jaw splitting under compression and the forces used to crush molluscs in the wild suggest increased LPJ fusion in the trophically polymorphic Herichthys minckleyi operates to strengthen the pharyngeal jaw. Among Heroine cichlid species, the presence of an external LPJ suture and feeding specialization on molluscs was evolutionarily quite variable, but greater LPJ fusion estimated from the amount of external suturing was highly correlated with molluscivory. Throughout cichlid diversification, increased pharyngeal jaw fusion via suturing has likely helped to reinforce the LPJ during pharyngeal processing thereby facilitating the ability of cichlids to exploit durable prey. PMID:16608685

  8. Built to fight: variable loading conditions and stress distribution in stag beetle jaws.

    PubMed

    Goyens, Jana; Dirckx, Joris; Aerts, Peter

    2015-08-01

    Designing very robust structures in an efficient way is a reoccurring challenge in engineering. For male stag beetle weaponry, the solution to this problem was evolved by natural and sexual selection. Stag beetle armature is adapted to perform under extreme circumstances: male stag beetles fight pugnacious battles over females, by using their extremely large jaws as ferocious weapons. During violent encounters, these jaws have to withstand forces with a wide range of unpredictable directions at several application points. We constructed 1020 finite element models with different input forces to investigate how the male jaws are structurally adapted to avoid failure. The cross-sectional shape of the jaw is adapted to provide robustness against the reaction forces of biting. Nevertheless, the jaw's shape cannot prevent the fact that bite forces induce relatively high material stresses compared to other force directions. Also, males do not confine themselves in combats to bite with the most robust jaw regions. Both observations emphasize the usefulness of bite force modulation to avoid jaw failure. This is likely effectuated by a sensory network in the jaw exoskeleton, as sensor densities are nicely correlated to the maximal material stress caused by 510 different loading directions. Probably, stag beetles use this sensory information to adjust their fighting strategy as well. Finally, male jaws also need to resist the forceful bites inflicted by opponents. Even though this loading applies at other locations along the jaw, and bends the jaw in the opposite direction, our models show that the jaws are equally robust against these external forces as they are against the forces caused by their own biting.

  9. A comparative study of identical VMAT plans with and without jaw tracking technique.

    PubMed

    Wu, Hao; Jiang, Fan; Yue, Haizhen; Hu, Qiaoqiao; Zhang, Jian; Liu, Zhuolun; Gong, Jian; Li, Sha; Geng, Jianhao; Zhang, Yibao

    2016-01-01

    The unwanted radiation transmission through the multileaf collimators could be reduced by the jaw tracking technique which is commercially available on Varian TrueBeam accelerators. On the basis of identical plans, this study aims to investigate the dosimetric impact of jaw tracking on the volumetric-modulated arc therapy (VMAT) plans. Using Eclipse treatment planning system (TPS), 40 jaw-tracking VMAT plans with various tumor volumes and shapes were optimized. Fixed jaw plans were created by editing the jaw coordinates of the jaw-tracking plans while other parameters were identical. The deliverability of this artificial modification was verified using COMPASS system via three-dimentional gamma analysis between the measurement-based reconstruction and the TPS-calculated dose distribution. Dosimetric parameters of dose-volume histogram (DVH) were compared to assess the improvement of dose sparing for organs at risk (OARs) in jaw-tracking plans. COMPASS measurements demonstrated that over 96.9% of structure volumes achieved gamma values less than 1.00 at criteria of 3 mm/3%. The reduction magnitudes of maximum and mean dose to various OARs ranged between 0.06% ~ 6.76% (0.04 ~ 7.29 Gy) and 0.09% ~ 7.81% (0.02 ~ 2.78 Gy), respectively, using jaw tracking, agreeing with the disparities of radiological characteristics between MLC and jaws. Jaw tracking does not change the delivery efficiency and total monitor units. The dosimetric comparison of VMAT plans with and without jaw tracking confirms the physics hypotheses that reduced transmission through tracking jaws will reduce doses to OARs without sacrificing the target dose coverage because it is meant to be covered by radiation beams going through the opening. PMID:27685122

  10. Validity and reliability of a Persian version of the quality of masticatory function questionnaire for edentulous patients

    PubMed Central

    Khodaeian, Niloufar; Rismanchian, Mansour; Behzadi, Ali; Jowkar, Fariba

    2016-01-01

    Background: Questionnaire is a suitable tool for evaluating the subjective masticatory function in edentulous patients. However, there is no validated Persian version of masticatory function questionnaire. The aim of this study was to evaluate the psychometric properties of the translated Persian version of the quality of masticatory function (QMF) questionnaire in terms of validity and reliability. Materials and Methods: After translation of QMF questionnaire to Persian, its validity was evaluated by four expert prosthodontists. The tool was applied on 62 complete denture wearers (31 men and 31 women, mean age 64.85 ± 1.98 years, mean time of edentulism 12.17 ± 3.21 years) via face-to-face interviews. Cronbach's alpha coefficient was used to measure internal consistency. Construct validity was analyzed using exploratory factor analysis. The Spearman's correlation coefficient between the summary scores of the tool and the years of edentulism and sex was also calculated for concurrent validity (α = 0.05) Results: It has been found that the Persian version of the questionnaire had an acceptable reliability (α = 0.910). Exploratory factor analysis extracted five domains: Masticatory problems with dentures, problems while consuming apple and carrot, meat products, fruits and vegetables, and changes need for better swallowing. A correlation was found between the tool scores and the years of edentulism (P = 0.001), but there was no correlation between sex and the tool scores (P = 0.841). Conclusion: The Persian version of QMF questionnaire for edentulous patients showed acceptable validity and reliability but further studies are needed to verify this tool. PMID:27076831

  11. A study of the emotional effects of tooth loss in an edentulous Gujarati population and its association with depression

    PubMed Central

    Shah, Rupal J.; Diwan, Fatema J.; Diwan, Munira J.; Chauhan, Vishal J.; Agrawal, Hemal S.; Patel, Ghanshyam C.

    2015-01-01

    Context: To fully estimate the burden of illness due to edentulism and establish valid treatment outcomes measures in this regard, it is equally important to study its psychosocial repercussions. Aims: The aim was to conduct a study to explore the emotional reactions to tooth loss, screen for current depressive symptoms and test for association between the two; among an edentulous Gujarati population. Settings and Design: A total of 147 edentulous people visiting the Prosthodontics Department were surveyed. Subjects and Methods: A questionnaire (based on previous studies) to test the emotional reactions to tooth loss and Nine Item-Patient Health Questionnaire to test for depression were used. Statistical Analysis Used: The data were analyzed using the Chi-square (χ2) test with the help of SPSS v. 18.0 (IBM Corp., Armonk, NY, USA). Results: Totally, 100 out of 147 edentulous people returned the questionnaire of which 58% experienced difficulties in accepting tooth loss and 37% felt unprepared for its effects. Those with difficulties accepting tooth loss had a greater effect on self esteem and social life, had more reservation about discussing tooth loss and was more likely to experience depression. Both groups were satisfied with dentures, had no problem meeting their friends or partners without dentures and leaving out dentures at night. Conclusion: About 58% of edentulous people had difficulties accepting tooth loss, which was unrelated to denture satisfaction. Respondents appeared to be restricted in social activities mainly due to functional limitations. Those with difficulties accepting tooth loss were more likely to experience depression. PMID:26929519

  12. Relevance of variations in the opposing dentition for the functionality of fixed and removable partial dentures: a systematic review.

    PubMed

    Pommer, Bernhard; Krainhöfner, Martin; Watzek, Georg; Tepper, Gabor; Dintsios, Charalabos-Markos

    2012-01-01

    The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a "biometric quality" tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture.

  13. Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

    PubMed Central

    Pommer, Bernhard; Krainhöfner, Martin; Watzek, Georg; Tepper, Gabor; Dintsios, Charalabos-Markos

    2012-01-01

    The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture. PMID:23193407

  14. Mechanoreceptor distribution in stag beetle jaws corresponds to the material stress in fights.

    PubMed

    Goyens, J; Dirckx, J; Aerts, P

    2015-05-01

    Male stag beetles (Lucanidae) use their extremely elongated jaws to pinch their rivals forcefully in male-male battles. The morphology of these jaws has to be a compromise between robustness (to withstand the bite forces), length and weight. Cyclommatus metallifer stag beetles circumvent this trade-off by reducing their bite force when biting with their slender jaw tips. Here we describe the functional mechanism behind the force modulation behaviour. Scanning Electron Microscopy and micro CT imaging show large numbers of small sensors in the jaw cuticle. We find a strong correlation between the distribution of these sensors and that of the material stress in the same jaw region during biting. The jaw sensors are mechanoreceptors with a small protrusion that barely protrudes above the undulating jaw surface. The sensors stimulate dendrites that extend from the neuronal cell body through the entire thickness of the jaw exoskeleton towards the sensors at the external surface. They form a sensory field that functions in a feedback mechanism to control the bite muscle force. This negative feedback mechanism enabled the stag beetles to evolve massive bite muscles without risking overloading their valuable jaws.

  15. The retro-articular process, streptostyly and the caecilian jaw closing system.

    PubMed

    Summers, Adam P; Wake, Marvalee H

    2005-01-01

    Caecilians have two functionally separate sets of jaw closing muscles. The jaw adductor muscles are parallel fibered muscles positioned close to the jaw joint and their lever mechanics suggests they are well suited to rapidly closing the jaws. A second set of muscles, the hypaxial interhyoideus posterior (IHP), levers the jaws closed by pulling on the retro-articular process (RA) of the lower jaw. Models of the lower jaw point out that the angle and length of the RA has a profound effect on the closure force exerted by the IHP. The caecilian skull is streptostylic - the quadrate-squamosal apparatus (QSA) moves relative to the rest of the skull, a condition that seems at odds with a well-ossified cranium. Modeling the contribution of this streptostylic suspension of the lower jaw shows that rotational freedom of the QSA amplifies the force of the IHP by redirecting force applied along the low axis of the lower jaw. Measurements from several species and life stages of preserved caecilians reveal a large variation in predicted bite force (as a multiple of IHP force) with age and phylogeny.

  16. The retro-articular process, streptostyly and the caecilian jaw closing system.

    PubMed

    Summers, Adam P; Wake, Marvalee H

    2005-01-01

    Caecilians have two functionally separate sets of jaw closing muscles. The jaw adductor muscles are parallel fibered muscles positioned close to the jaw joint and their lever mechanics suggests they are well suited to rapidly closing the jaws. A second set of muscles, the hypaxial interhyoideus posterior (IHP), levers the jaws closed by pulling on the retro-articular process (RA) of the lower jaw. Models of the lower jaw point out that the angle and length of the RA has a profound effect on the closure force exerted by the IHP. The caecilian skull is streptostylic - the quadrate-squamosal apparatus (QSA) moves relative to the rest of the skull, a condition that seems at odds with a well-ossified cranium. Modeling the contribution of this streptostylic suspension of the lower jaw shows that rotational freedom of the QSA amplifies the force of the IHP by redirecting force applied along the low axis of the lower jaw. Measurements from several species and life stages of preserved caecilians reveal a large variation in predicted bite force (as a multiple of IHP force) with age and phylogeny. PMID:16351979

  17. Removable Partial Denture Supported by Implants with Prefabricated Telescopic Abutments - A Case Report

    PubMed Central

    Sehgal, Komal

    2014-01-01

    Implants have been designed to rehabilitate edentulous patients with fixed prosthesis or implant supported overdentures. Implant-supported single crowns and fixed partial dentures have become successful treatment alternatives to removable and fixed partial dentures. However, it is common to have clinical situations which make it impossible to use conventional as well as implant supported fixed partial dentures. The implant supported removable partial dentures can be a treatment modality that offers the multitude of benefits of implant-based therapy—biologic, biomechanical, social, and psychological to such patients. The aim of this article is to present a case report describing the fabrication and advantages of removable partial denture supported by teeth and implants for a patient with long edentulous span. The patient was satisfied with his dentures in terms of function and aesthetics. Regular follow-up visits over a period of three years revealed that the periodontal condition of remaining natural dentition and peri-implant conditions were stable. There was no evidence of excessive residual ridge resorption or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. PMID:25121066

  18. Epilepsy (partial)

    PubMed Central

    2011-01-01

    Introduction About 3% of people will be diagnosed with epilepsy during their lifetime, but about 70% of people with epilepsy eventually go into remission. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of starting antiepileptic drug treatment following a single seizure? What are the effects of drug monotherapy in people with partial epilepsy? What are the effects of additional drug treatments in people with drug-resistant partial epilepsy? What is the risk of relapse in people in remission when withdrawing antiepileptic drugs? What are the effects of behavioural and psychological treatments for people with epilepsy? What are the effects of surgery in people with drug-resistant temporal lobe epilepsy? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 83 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antiepileptic drugs after a single seizure; monotherapy for partial epilepsy using carbamazepine, gabapentin, lamotrigine, levetiracetam, phenobarbital, phenytoin, sodium valproate, or topiramate; addition of second-line drugs for drug-resistant partial epilepsy (allopurinol, eslicarbazepine, gabapentin, lacosamide, lamotrigine, levetiracetam, losigamone, oxcarbazepine, retigabine, tiagabine, topiramate, vigabatrin, or zonisamide); antiepileptic drug withdrawal for people with partial or

  19. Jaw position uncertainty and adjacent fields in breast cancer radiotherapy.

    PubMed

    Hedin, Emma; Bäck, Anna; Chakarova, Roumiana

    2015-11-08

    Locoregional treatment of breast cancer involves adjacent, half blocked fields matched at isocenter. The objective of this work is to study the dosimetric effects of the uncertainties in jaw positioning for such a case, and how a treatment planning protocol including adjacent field overlap of 1 mm affects the dose distribution. A representative treatment plan, involving 6 and 15 photon beams, for a patient treated at our hospital is chosen. Monte Carlo method (EGSnrc/BEAMnrc) is used to simulate the treatment. Uncertainties in jaw positioning of ± 1 mm are addressed, which implies extremes in reality of 2 mm field gap/overlap when planning adjacent fields without overlap and 1 mm gap or 3 mm overlap for a planning protocol with 1 mm overlap. Dosimetric parameters for PTV, lung and body are analyzed. Treatment planning protocol with 1 mm overlap of the adjacent fields does not considerably counteract possible underdosage of the target in the case studied. PTV-V95% is for example reduced from 95% for perfectly aligned fields to 90% and 91% for 2 mm and 1 mm gap, respectively. However, the risk of overdosage in PTV and in healthy soft tissue is increased when following the protocol with 1 mm overlap. A 3 mm overlap compared to 2 mm overlap results in an increase in maximum dose to PTV, PTV-D2%, from 113% to 121%. V120% for 'Body-PTV' is also increased from 5 cm(3) to 14 cm(3). A treatment planning protocol with 1 mm overlap does not considerably improve the coverage of PTV in the case of erroneous jaw positions causing gap between fields, but increases the overdosage in PTV and doses to healthy tissue, in the case of overlapping fields, for the case investigated.

  20. [Bone tissue morphological structure in congenital deformations of the jaws].

    PubMed

    Shishkanov, A V; Panin, M G; Shipkova, T P; Chumakov, A A; Komnova, Z D

    2001-01-01

    Morphological structure of bone tissue was studied in various types of congenital deformations of the jaws. Morphological changes in the bone with deformations and the severity of these disorders depended not so much on the type on the deformation, but mainly on its severity, which can be explained by a drastic increase of functional exercise because of impaired occlusion and impossibility of proper chewing. Decelerated weak restructuring of bone tissue and imperfect osteogenesis in deformed bone, similar in various types of deformations, were demonstrated on morphological material. These changes can affect the regenerative potential of the bone in operated zones. PMID:11881460

  1. [Benign odontogenic tumor in the lower jaw: A case report].

    PubMed

    Bassetti, Renzo; Tomasetti, Patrick; Crameri, Manuel; Kuttenberger, Johannes

    2016-01-01

    Odontomas are classified within the group of odontogenic epithelial tumors with odontogenic ectomesenchyme with or without hard tissue formation. Together with ameloblastomas and keratocystic odontogenic tumors they are counted among the most common odontogenic tumors. Their growth is self-limiting and mostly, they are discovered accidentally as part of a x-ray examination. A common finding is that odontomas are associated with an unerupted permanent tooth. The aim of the present case report is to present the step-by-step procedure of a surgical odontoma removal in the lingual premolar/canine area of the lower jaw. PMID:27142310

  2. [Benign odontogenic tumor in the lower jaw: A case report].

    PubMed

    Bassetti, Renzo; Tomasetti, Patrick; Crameri, Manuel; Kuttenberger, Johannes

    2016-01-01

    Odontomas are classified within the group of odontogenic epithelial tumors with odontogenic ectomesenchyme with or without hard tissue formation. Together with ameloblastomas and keratocystic odontogenic tumors they are counted among the most common odontogenic tumors. Their growth is self-limiting and mostly, they are discovered accidentally as part of a x-ray examination. A common finding is that odontomas are associated with an unerupted permanent tooth. The aim of the present case report is to present the step-by-step procedure of a surgical odontoma removal in the lingual premolar/canine area of the lower jaw.

  3. Pharmacogenetics of Bisphosphonate-associated Osteonecrosis of the Jaw.

    PubMed

    Fung, P L; Nicoletti, P; Shen, Y; Porter, S; Fedele, S

    2015-11-01

    Osteonecrosis of the jaws (ONJ) is a potentially severe disorder that develops in a subgroup of individuals who have used bisphosphonate (BP) medications. Several clinical risk factors have been associated with the risk of ONJ development, but evidence is limited and in most instances ONJ remains an unpredictable adverse drug reaction. Interindividual genetic variability can contribute to explaining ONJ development in a subset of BP users and the discovery of relevant associated gene variants could lead to the identification of individuals at higher risk. No genetic variant has been found to be robustly associated with susceptibility to ONJ.

  4. 3D-model building of the jaw impression

    NASA Astrophysics Data System (ADS)

    Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.

    1997-03-01

    A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.

  5. Monocortical Deep Circumflex Iliac Artery Flap in Jaw Reconstruction.

    PubMed

    Moon, Seong-Yong

    2015-06-01

    Conventionally deep circumflex iliac artery (DCIA) flap had been harvested as bicortical form. However, several complications and adverse effects occurred such as abnormal hip contour, hernia, severe bleeding tendency, gait disturbance, and hypoesthesia. All the 9 patients required reconstruction of the jaw with microvascular free flaps after radical resection. Monocortical bone segment was harvested from the anterior iliac crest, and the amount of bone harvested was from 47 to 90 mm (mean, 63 ± 14.6). Monocortical deep circumflex iliac artery flap has sufficient advantages in donor-site morbidity, which is one of the factors to choose flap.

  6. Bisphosphonate related osteonecrosis of the jaws: a review.

    PubMed

    Stepaniuk, Kevin

    2011-01-01

    Bisphosphonate use has increased in veterinary medicine over the last decade. During this time, bisphosphonate related osteonecrosis of the jaws (BRONJ) in human patients has been identified. Only recently was a dog model for BRONJ developed for human oral surgery and medicine. Veterinary patients treated with bisphosphonates may be at an increased risk for BRONJ There has been little, to no, investigation of potential long term side-effects of bisphosphonate use in veterinary patients; potential sequelae are unknown. The history of bisphosphonates, their use, and BRONJ in veterinary patients are discussed.

  7. Osteonecrosis of the jaw in patient with denosumab therapy

    PubMed Central

    Olate, Sergio; Uribe, Francisca; Martinez, Felipe; Almeida, Andrés; Unibazo, Alejandro

    2014-01-01

    Osteonecrosis (ON) of the jaw has previously been linked to the use of biphosphonates; however, new drugs, also shown similar conditions. This article presents a female patient with mandibular ON related to the use of denosumab. The 55-year-old presented with bone exposure with 8 months of evolution after a dental extraction. The patient began subcutaneous injections of 60 mg denosumab four months prior to the extraction and the lesion remained after the procedure. The patient, with 14 months of follow-up, show mandible ON with no favorable evolution. The clinical condition is presented and the literature of ON associated with denosumab is discussed. PMID:25419421

  8. Effects of Salivary Oxidative Markers on Edentulous Patients’ Satisfaction with Prosthetic Denture Treatments: A Pilot Study

    PubMed Central

    Feng, Sheng-Wei; Miao, Nae-Fang; Lin, Pei-Huan; Lin, Che-Tong; Tsai, Shin-Han; Huang, Yung-Kai

    2016-01-01

    Objectives The purpose of this study was to assess relationships among periodontal conditions, salivary antioxidant levels, and patients’ satisfaction with their prostheses. Methods This study was conducted at the Division of Prosthodontics, Department of Dentistry, Taipei Medical University Hospital. The periodontal condition of patients was based on an assessment of the plaque index (PI) and gingival index (GI). The pH value, flow rate, and buffer capacity of the saliva were estimated. The salivary total antioxidant status (TAS) and superoxide dismutase (SOD) level were also determined. Patients’ satisfaction with prosthetic treatments was evaluated using the Chinese version of the short-form Oral Health Impact Profile (OHIP-14C). A multivariate regression model was used to determine whether patients’ satisfaction with prosthetic treatment was affected by their oral health status. Results In total, 35 edentulous patients were recruited. In the Spearman correlation analysis, salivary pH (r = -0.36, p = 0.03) and the buffer ability (r = -0.48, p<0.01) were associated with OHIP-14C scores. In the multivariate analysis, patients who had a higher GI also had a higher score of physical disabilities (β = 1.38, p = 0.04). Levels of SOD increased with the scores of psychological discomfort (β = 0.33 U/g protein, p = 0.04). Conclusions This study suggested that both the GI and SOD levels were associated with patients’ satisfaction with prosthetic treatments. To the best of our knowledge, this is the first study to elucidate the relationship between OHIP scores and salivary oxidative markers in edentulous patients. PMID:26986841

  9. An Ancient Gene Network Is Co-opted for Teeth on Old and New Jaws

    PubMed Central

    Fraser, Gareth J; Hulsey, C. Darrin; Bloomquist, Ryan F; Uyesugi, Kristine; Manley, Nancy R; Streelman, J. Todd

    2009-01-01

    Vertebrate dentitions originated in the posterior pharynx of jawless fishes more than half a billion years ago. As gnathostomes (jawed vertebrates) evolved, teeth developed on oral jaws and helped to establish the dominance of this lineage on land and in the sea. The advent of oral jaws was facilitated, in part, by absence of hox gene expression in the first, most anterior, pharyngeal arch. Much later in evolutionary time, teleost fishes evolved a novel toothed jaw in the pharynx, the location of the first vertebrate teeth. To examine the evolutionary modularity of dentitions, we asked whether oral and pharyngeal teeth develop using common or independent gene regulatory pathways. First, we showed that tooth number is correlated on oral and pharyngeal jaws across species of cichlid fishes from Lake Malawi (East Africa), suggestive of common regulatory mechanisms for tooth initiation. Surprisingly, we found that cichlid pharyngeal dentitions develop in a region of dense hox gene expression. Thus, regulation of tooth number is conserved, despite distinct developmental environments of oral and pharyngeal jaws; pharyngeal jaws occupy hox-positive, endodermal sites, and oral jaws develop in hox-negative regions with ectodermal cell contributions. Next, we studied the expression of a dental gene network for tooth initiation, most genes of which are similarly deployed across the two disparate jaw sites. This collection of genes includes members of the ectodysplasin pathway, eda and edar, expressed identically during the patterning of oral and pharyngeal teeth. Taken together, these data suggest that pharyngeal teeth of jawless vertebrates utilized an ancient gene network before the origin of oral jaws, oral teeth, and ectodermal appendages. The first vertebrate dentition likely appeared in a hox-positive, endodermal environment and expressed a genetic program including ectodysplasin pathway genes. This ancient regulatory circuit was co-opted and modified for teeth in oral

  10. Deranged jaw-neck motor control in whiplash-associated disorders.

    PubMed

    Eriksson, Per-Olof; Zafar, Hamayun; Häggman-Henrikson, Birgitta

    2004-02-01

    Recent findings of simultaneous and well coordinated head-neck movements during single as well as rhythmic jaw opening-closing tasks has led to the conclusion that 'functional jaw movements' are the result of activation of jaw as well as neck muscles, leading to simultaneous movements in the temporomandibular, atlanto-occipital and cervical spine joints. It can therefore be assumed that disease or injury to any of these joint systems would disturb natural jaw function. To test this hypothesis, amplitudes, temporal coordination, and spatiotemporal consistency of concomitant mandibular and head-neck movements during single maximal jaw opening-closing tasks were analysed in 25 individuals suffering from whiplash-associated disorders (WAD) using optoelectronic movement recording technique. In addition, the relative durations for which the head position was equal to, leading ahead of, or lagging behind the mandibular position during the entire jaw opening-closing cycle were determined. Compared with healthy individuals, the WAD group showed smaller amplitudes, and changed temporal coordination between mandibular and head-neck movements. No divergence from healthy individuals was found for the spatiotemporal consistency or for the analysis during the entire jaw opening-closing cycle. These findings in the WAD group of a 'faulty', but yet consistent, jaw-neck behavior may reflect a basic importance of linked control of the jaw and neck sensory-motor systems. In conclusion, the present results suggest that neck injury is associated with deranged control of mandibular and head-neck movements during jaw opening-closing tasks, and therefore might compromise natural jaw function.

  11. Independently evolved upper jaw protrusion mechanisms show convergent hydrodynamic function in teleost fishes.

    PubMed

    Staab, Katie Lynn; Holzman, Roi; Hernandez, L Patricia; Wainwright, Peter C

    2012-05-01

    A protrusible upper jaw has independently evolved multiple times within teleosts and has been implicated in the success of two groups in particular: Acanthomorpha and Cypriniformes. We use digital particle image velocimetry (DPIV) to compare suction feeding flow dynamics in a representative of each of these clades: goldfish and bluegill. Using DPIV, we contrast the spatial pattern of flow, the temporal relationship between flow and head kinematics, and the contribution of jaw protrusion to the forces exerted on prey. As expected, the spatial patterns of flow were similar in the two species. However, goldfish were slower to reach maximal kinematic excursions, and were more flexible in the relative timing of jaw protrusion, other jaw movements and suction flows. Goldfish were also able to sustain flow speeds for a prolonged period of time as compared with bluegill, in part because goldfish generate lower peak flow speeds. In both species, jaw protrusion increased the force exerted on the prey. However, slower jaw protrusion in goldfish resulted in less augmentation of suction forces. This difference in force exerted on prey corresponds with differences in trophic niches and feeding behavior of the two species. The bluegill uses powerful suction to capture insect larvae whereas the goldfish uses winnowing to sort through detritus and sediment. The kinethmoid of goldfish may permit jaw protrusion that is independent of lower jaw movement, which could explain the ability of goldfish to decouple suction flows (due to buccal expansion) from upper jaw protrusion. Nevertheless, our results show that jaw protrusion allows both species to augment the force exerted on prey, suggesting that this is a fundamental benefit of jaw protrusion to suction feeders. PMID:22496281

  12. Static jaw collimation settings to minimize radiation dose to normal brain tissue during stereotactic radiosurgery

    SciTech Connect

    Han, Eun Young; Zhang Xin; Yan Yulong; Sharma, Sunil; Penagaricano, Jose; Moros, Eduardo; Corry, Peter

    2012-01-01

    At University of Arkansas for Medical Sciences (UAMS) intracranial stereotactic radiosurgery (SRS) is performed by using a linear accelerator with an add-on micromultileaf collimator (mMLC). In our clinical setting, static jaws are automatically adapted to the furthest edge of the mMLC-defined segments with 2-mm (X jaw) and 5-mm (Y jaw) margin and the same jaw values are applied for all beam angles in the treatment planning system. This additional field gap between the static jaws and the mMLC allows additional radiation dose to normal brain tissue. Because a radiosurgery procedure consists of a single high dose to the planning target volume (PTV), reduction of unnecessary dose to normal brain tissue near the PTV is important, particularly for pediatric patients whose brains are still developing or when a critical organ, such as the optic chiasm, is near the PTV. The purpose of this study was to minimize dose to normal brain tissue by allowing minimal static jaw margin around the mMLC-defined fields and different static jaw values for each beam angle or arc. Dose output factors were measured with various static jaw margins and the results were compared with calculated doses in the treatment planning system. Ten patient plans were randomly selected and recalculated with zero static jaw margins without changing other parameters. Changes of PTV coverage, mean dose to predefined normal brain tissue volume adjacent to PTV, and monitor units were compared. It was found that the dose output percentage difference varied from 4.9-1.3% for the maximum static jaw opening vs. static jaw with zero margins. The mean dose to normal brain tissue at risk adjacent to the PTV was reduced by an average of 1.9%, with negligible PTV coverage loss. This dose reduction strategy may be meaningful in terms of late effects of radiation, particularly in pediatric patients. This study generated clinical knowledge and tools to consistently minimize dose to normal brain tissue.

  13. Fine morphology of the jaw apparatus of Puncturella noachina (Fissurellidae, Vetigastropoda).

    PubMed

    Vortsepneva, Elena; Ivanov, Dmitry; Purschke, Günter; Tzetlin, Alexander

    2014-07-01

    Jaws of various kinds occur in virtually all groups of Mollusca, except for Polyplacophora and Bivalvia. Molluscan jaws are formed by the buccal epithelium and either constitute a single plate, a paired formation or a serial structure. Buccal ectodermal structures in gastropods are rather different. They can be nonrenewable or having final growth, like the hooks in Clione (Gastropoda, Gymnosomata). In this case, they are formed by a single cell. Conversely, they can be renewable during the entire life span and in this case they are formed by a set of cells, like the formation of the radula. The fine structure of the jaws was studied in the gastropod Puncturella noachina. The jaw is situated in the buccal cavity and consists of paired elongated cuticular plates. On the anterior edge of each cuticular plate there are numerous longitudinally oriented rodlets disposed over the entire jaw surface and immersed into a cuticular matrix. The jaw can be divided into four zones situated successively toward the anterior edge: 1) the posterior area: the zone of formation of the thick cuticle covering the entire jaw and forming the electron-dense outer layer of the jaw plate; 2) the zone of rodlet formation; 3) the zone of rodlet arrangement; and 4) the anterior zone: the free scraping edge of the plate, or the erosion zone. In the general pattern of jaw formation, Puncturella noachina resembles Testudinalia tessulata (Patellogastropoda) studied previously. The basis of the jaw is a cuticular plate formed by the activity of the strongly developed microvillar apparatus of the gnathoepithelium. However, the mechanism of renewal of the jaw anterior part in P. noachina is much more complex as its scraping edge consists not just of a thick cuticular matrix rather than of a system of denticles being the projecting endings of rodlets. PMID:24549973

  14. A Preliminary Analysis of the Relationship between Jaw-Muscle Architecture and Jaw-Muscle Electromyography during Chewing Across Primates

    PubMed Central

    Vinyard, Christopher J.; Taylor, Andrea B.

    2011-01-01

    The architectural arrangement of the fibers within a muscle has a significant impact on how a muscle functions. Recent work on primate jaw-muscle architecture demonstrates significant associations with dietary variation and feeding behaviors. In this study, the relationship between masseter and temporalis muscle architecture and jaw-muscle activity patterns is explored using Belanger's treeshrews and 11 primate species, including three genera of strepsirrhines (Lemur, Otolemur) and five genera of anthropoids (Aotus, Callithrix, Cebus, Macaca, Papio). Jaw-muscle weights, fiber lengths and physiologic cross-sectional areas (PCSA) were quantified for this preliminary analysis or collected from the literature and compared to published electromyographic (EMG) recordings from these muscles. Results indicate that masseter architecture is unrelated to the superficial masseter working-side/balancing-side (W/B) ratio across primate species. Alternatively, relative temporalis architecture is correlated with temporalis W/B ratios across primates. Specifically, relative temporalis PCSA is inversely related to the W/B ratio for the anterior temporalis indicating that as animals recruit a larger relative percentage of their balancing-side temporalis, they possess the ability to generate relatively larger amounts of force from these muscles. These findings support three broader conclusions. First, masseter muscle architecture may have experienced divergent evolution across different primate clades related to novel functional roles in different groups. Second, the temporalis may be functionally constrained (relative to the masseter) across primates in its functional role of creating vertical occlusal forces during chewing. Finally, the contrasting results for the masseter and temporalis suggest that the fiber architecture of these muscles has evolved as distinct functional units in primates. PMID:20235313

  15. "Phossy Jaw" and "Bis-phossy Jaw" of the 19th and the 21st Centuries: The Diuturnity of John Walker and the Friction Match.

    PubMed

    Pollock, Richard A; Brown, Ted W; Rubin, David M

    2015-09-01

    Some 200 years ago, workers developed gingivitis, periodontal disease, alveolar crest bone sequestra, and draining fistulae after exposure to phosphorous fumes and phosphorous paste in the manufacture of the friction match. Many also suffered loss of teeth and pathologic fracture of the mandible. Known as "phossy jaw," the constellation rather abruptly vanished following the International Berne Convention of 1906. Today, "bis-phossy jaw" (bisphosphonate-induced osteonecrosis of the jaw) has surfaced with pathologic fractures and other features common to its predecessor, "phossy jaw." This modern equivalent is reported with ever-increasing frequency and is presented here in the format of a brief historical review and a case report that includes segmental en bloc extirpation of necrotic mandible and pain-free salvage. Computerized imagery and three-dimensional printing technology were successfully chosen to create and apply a custom titanium bone plate, without free-tissue transfer. PMID:27053988

  16. "Phossy Jaw" and "Bis-phossy Jaw" of the 19th and the 21st Centuries: The Diuturnity of John Walker and the Friction Match.

    PubMed

    Pollock, Richard A; Brown, Ted W; Rubin, David M

    2015-09-01

    Some 200 years ago, workers developed gingivitis, periodontal disease, alveolar crest bone sequestra, and draining fistulae after exposure to phosphorous fumes and phosphorous paste in the manufacture of the friction match. Many also suffered loss of teeth and pathologic fracture of the mandible. Known as "phossy jaw," the constellation rather abruptly vanished following the International Berne Convention of 1906. Today, "bis-phossy jaw" (bisphosphonate-induced osteonecrosis of the jaw) has surfaced with pathologic fractures and other features common to its predecessor, "phossy jaw." This modern equivalent is reported with ever-increasing frequency and is presented here in the format of a brief historical review and a case report that includes segmental en bloc extirpation of necrotic mandible and pain-free salvage. Computerized imagery and three-dimensional printing technology were successfully chosen to create and apply a custom titanium bone plate, without free-tissue transfer.

  17. Jaws and teeth of the earliest bony fishes.

    PubMed

    Botella, Hector; Blom, Henning; Dorka, Markus; Ahlberg, Per Erik; Janvier, Philippe

    2007-08-01

    Extant jawed vertebrates, or gnathostomes, fall into two major monophyletic groups, namely chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods). Fossil representatives of the osteichthyan crown group are known from the latest Silurian period, 418 million years (Myr) ago, to the present. By contrast, stem chondrichthyans and stem osteichthyans are still largely unknown. Two extinct Palaeozoic groups, the acanthodians and placoderms, may fall into these stem groups or the common stem group of gnathostomes, but their relationships and monophyletic status are both debated. Here we report unambiguous evidence for osteichthyan characters in jaw bones referred to the late Silurian (423-416-Myr-old) fishes Andreolepis hedei and Lophosteus superbus, long known from isolated bone fragments, scales and teeth, and whose affinities to, or within, osteichthyans have been debated. The bones are a characteristic osteichthyan maxillary and dentary, but the organization of the tooth-like denticles they bear differs from the large, conical teeth of crown-group osteichthyans, indicating that they can be assigned to the stem group. Andreolepis and Lophosteus are thus not only the oldest but also the most phylogenetically basal securely identified osteichthyans known so far.

  18. Oral bisphosphonate associated osteonecrosis of the jaws: three case reports.

    PubMed

    Malden, N J; Pai, A Y

    2007-07-28

    Bisphosphonate associated osteonecrosis of the jaws (BONJ) has been well documented recently in relation to intravenous preparations of the drug. These are most commonly used as part of the management of hypercalcaemia of malignancy and metastatic bone disease but BONJ can also occur in association with oral bisphosphonate use. The oral preparations can also be prescribed in the management of metastatic bone disease but are more commonly used for the prevention and treatment of osteoporosis. Three case reports are presented in which alendronate, risedronate and ibandronate have been associated with osteonecrosis of the jaws. A review of the recent literature is used in the discussion of the management of these cases. The authors conclude, in agreement with other published authors, that prevention and early detection could be improved to reduce the occurrence and severity of this condition. However when BONJ is diagnosed, the early application of a closely monitored conservative regimen, with consideration given to discontinuation of the bisphosphonate, may give the best chance of containing or resolving the condition.

  19. Monitoring of Infant Feeding Behavior Using a Jaw Motion Sensor

    PubMed Central

    Farooq, Muhammad; Chandler-Laney, Paula C; Hernandez-Reif, Maria; Sazonov, Edward

    2016-01-01

    Rapid weight gain during infancy increases the risk of obesity. Given that infant feeding may contribute to rapid weight gain, it would be useful to develop objective tools which can monitor infant feeding behavior. This paper presents an objective method for examining infant sucking count during meals. A piezoelectric jaw motion sensor and a video camera were used to monitor jaw motions of 10 infants during a meal. Videotapes and sensor signals were annotated by two independent human raters, counting the number of sucks in each 10 second epoch. Annotated data were used as a gold standard for the development of the computer algorithms. The sensor signal was de-noised and normalized prior to computing the per-epoch sucking counts. A leave-one-out cross-validation scheme resulted in a mean error rate of −9.7% and an average intra-class correlation coefficient value of 0.86 between the human raters and the algorithm. PMID:25708375

  20. Effective doses from cone beam CT investigation of the jaws

    PubMed Central

    Davies, J; Johnson, B; Drage, NA

    2012-01-01

    Objectives The purpose of the study was to calculate the effective dose delivered to the patient undergoing cone beam (CB) CT of the jaws and maxillofacial complex using the i-CAT Next Generation CBCT scanner (Imaging Sciences International, Hatfield, PA). Methods A RANDO® phantom (The Phantom Laboratory, Salem, NY) containing thermoluminence dosemeters were scanned 10 times for each of the 6 imaging protocols. Effective doses for each protocol were calculated using the 1990 and approved 2007 International Commission on Radiological Protection (ICRP) recommended tissue weighting factors (E1990, E2007). Results The effective dose for E1990 and E2007, respectively, were: full field of view (FOV) of the head, 47 μSv and 78 μSv; 13 cm scan of the jaws, 44 μSv and 77 μSv; 6 cm standard mandible, 35 μSv and 58 μSv; 6 cm high resolution mandible, 69 μSv and 113 μSv; 6 cm standard maxilla, 18 μSv and 32 μSv; and 6 cm high resolution maxilla, 35 μSv and 60 μSv. Conclusions Using the new generation of CBCT scanner, the effective dose is lower than the original generation machine for a similar FOV using the ICRP 2007 tissue weighting factors. PMID:22184626

  1. DMP1 processing is essential to dentin and jaw formation.

    PubMed

    Sun, Y; Lu, Y; Chen, L; Gao, T; D'Souza, R; Feng, J Q; Qin, C

    2011-05-01

    Dentin matrix protein 1 (DMP1), an acidic protein that is essential to the mineralization of bone and dentin, exists as proteolytically processed fragments in the mineralized tissues. In this study, we characterized the tooth and jaw phenotypes in transgenic mice containing no wild-type DMP1, but expressing a mutant DMP1 in which Asp(213), a residue at one cleavage site, was replaced by Ala(213) (named "Dmp1-KO/D213A-Tg" mice). The teeth and mandible of Dmp1-KO/D213A-Tg mice were compared with those of wild-type, Dmp1-knockout (Dmp1-KO), and Dmp1-KO mice expressing the normal Dmp1 transgene. The results showed that D213A-DMP1 was not cleaved in dentin, and the expression of D213A-DMP1 failed to rescue the defects in the dentin, cementum, and alveolar bones in the Dmp1-KO mice. These findings indicate that the proteolytic processing of DMP1 is essential to the formation and mineralization of dentin, cementum, and jaw bones.

  2. A new 4-dimensional imaging system for jaw tracking.

    PubMed

    Lauren, Mark

    2014-01-01

    A non-invasive 4D imaging system that produces high resolution time-based 3D surface data has been developed to capture jaw motion. Fluorescent microspheres are brushed onto both tooth and soft-tissue areas of the upper and lower arches to be imaged. An extraoral hand-held imaging device, operated about 12 cm from the mouth, captures a time-based set of perspective image triplets of the patch areas. Each triplet, containing both upper and lower arch data, is converted to a high-resolution 3D point mesh using photogrammetry, providing the instantaneous relative jaw position. Eight 3D positions per second are captured. Using one of the 3D frames as a reference, a 4D model can be constructed to describe the incremental free body motion of the mandible. The surface data produced by this system can be registered to conventional 3D models of the dentition, allowing them to be animated. Applications include integration into prosthetic CAD and CBCT data. PMID:24791467

  3. Robust 3D reconstruction system for human jaw modeling

    NASA Astrophysics Data System (ADS)

    Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.

    1999-03-01

    This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.

  4. Molecular synapomorphies resolve evolutionary relationships of extant jawed vertebrates

    PubMed Central

    Venkatesh, Byrappa; Erdmann, Mark V.; Brenner, Sydney

    2001-01-01

    The evolutionary relationships of gnathostomes (jawed vertebrates), which comprise chondrichthyans (cartilaginous fishes), lobe-finned fishes (coelacanths and lungfishes), tetrapods, and actinopterygians (ray-finned fishes), have been debated for almost a century. Phylogenetic analyses based on fossils, morphology, and molecular sequences have generated different models of relationships that remain unresolved. We identified 13 derived shared molecular markers (synapomorphies) that define clades in the vertebrate lineage and used them to resolve the phylogenetic relationships of extant jawed vertebrates. Our markers include the presence or absence of insertions and deletions in coding sequences, nuclear introns, and alternatively spliced transcripts. The synapomorphies identified by us are congruent with each other and give rise to a single phylogenetic tree. This tree confirms that chondrichthyans are basal to all living gnathostomes, that lungfishes (Dipnoi) are the closest living relatives of tetrapods, and that bichirs (Cladistia) are the living members of the most ancient family of ray-finned fishes. Our study also provides molecular evidence to support the monophyly of living tetrapods and teleosts. PMID:11553795

  5. Osteosarcoma of the jaws: case report on synchronous multicentric osteosarcomas.

    PubMed

    Jia, Shengnan; Li, Binbin

    2014-06-01

    Research has shown that osteosarcomas display high potential for metastasis to the lungs, pleurae and bones. Mandible, on the other hand, is an uncommon site for metastatic tumour cell colonization. Nevertheless, a metastatic tumour to mandible might be the first indication of an undiscovered malignancy at a distant site. This case report presents a case of a 61-year-old female patient. An osteosarcoma metastasized to her mandible shortly after the curettage of her jaw cyst. Both the metastatic osteosarcoma and the jaw cyst were confirmed by pathology. Initially, bilateral well-defined radiolucent lesions were shown in her panoramic X-ray image. Also, the diagnosis of a dentigerous cyst was made, based on histology. Two months later, a mixed radiolucent-radio opaque mass, which was confirmed as an osteosarcoma by pathology later, occupied the site of the previously enucleated dentigerous cyst, in her right mandible. Then, an identical osteosarcoma was found in the left pelvis on further doing overall radiological and pathological examinations. The pathologic hypotheses, treatment modality and follow-up of this case have also been presented.

  6. Osteosarcoma of the Jaws: Case Report on Synchronous Multicentric Osteosarcomas

    PubMed Central

    Jia, Shengnan

    2014-01-01

    Research has shown that osteosarcomas display high potential for metastasis to the lungs, pleurae and bones. Mandible, on the other hand, is an uncommon site for metastatic tumour cell colonization. Nevertheless, a metastatic tumour to mandible might be the first indication of an undiscovered malignancy at a distant site. This case report presents a case of a 61-year-old female patient. An osteosarcoma metastasized to her mandible shortly after the curettage of her jaw cyst. Both the metastatic osteosarcoma and the jaw cyst were confirmed by pathology. Initially, bilateral well-defined radiolucent lesions were shown in her panoramic X-ray image. Also, the diagnosis of a dentigerous cyst was made, based on histology. Two months later, a mixed radiolucent-radio opaque mass, which was confirmed as an osteosarcoma by pathology later, occupied the site of the previously enucleated dentigerous cyst, in her right mandible. Then, an identical osteosarcoma was found in the left pelvis on further doing overall radiological and pathological examinations. The pathologic hypotheses, treatment modality and follow-up of this case have also been presented. PMID:25121065

  7. Bisphosphonate-related osteonecrosis of the jaw: a pictorial review.

    PubMed

    Morag, Yoav; Morag-Hezroni, Michal; Jamadar, David A; Ward, Brent B; Jacobson, Jon A; Zwetchkenbaum, Samuel R; Helman, Joseph

    2009-11-01

    Bisphosphonate-related osteonecrosis of the jaw (ONJ) is characterized by nonhealing exposed bone in the maxillofacial region in patients who have undergone bisphosphonate treatment. The underlying etiology is unclear and may be multifactorial. The diagnosis is primarily clinical. Diagnostic tissue sampling may exacerbate the process and is typically avoided, necessitating other diagnostic approaches. The appearance of ONJ at diagnostic imaging is variable and includes sclerotic, lytic, or mixed lesions with possible periosteal reaction, pathologic fractures, and extension to soft tissues. There is a spectrum of signal intensity changes on T1- and T2-weighted magnetic resonance (MR) images with variable enhancement, findings that may correspond to the clinical and histopathologic stage of the process. Bone scintigraphy is sensitive with increased uptake in the area of the lesion. Although the imaging findings are nonspecific, there appears to be a role for imaging in the management of ONJ. Radiography is relatively insensitive but typically employed as the first line of radiologic investigation. Computed tomography and MR imaging are more precise in demonstrating the extent of the lesion. A number of imaging modalities have revealed lesions that may be associated with bisphosphonate exposure in asymptomatic individuals or in the context of nonspecific symptoms. The risk of these lesions advancing to overt clinical disease is unknown at this time. The radiologist should be aware of ONJ and include it in the differential diagnosis when evaluating patients with a history of bisphosphonate therapy without jaw irradiation, so as to avoid potentially harmful biopsies.

  8. Anatomically based modelling of the human skull and jaw.

    PubMed

    van Essen, N L; Anderson, I A; Hunter, P J; Carman, J; Clarke, R D; Pullan, A J

    2005-01-01

    We present here an anatomically based model of the human masticatory system that provides a framework for simulating the complex chewing process. The initial motivation for creating this model was the desire to have a computational model of the human jaw that can be used to simulate the action of simple bites, and to calculate the stresses and forces on the teeth that are involved. The model created also provides a platform that can be used to investigate other features of the masticatory system. To construct this global model, individual models of the bones of the skull and jaw were created from generic data sets. Geometric models of the muscles of mastication were also created and attached to the appropriate bones. To complete this initial model, representations of the crowns of the teeth were created and a basic model of the temporomandibular joint (TMJ) was included. The finite element method was used to solve for the stresses and strains created by the loading conditions during a clenching simulation involving the mandible bone. The model presented here is also discussed in relation to a model of the entire musculo-skeletal system being developed as part of the Physiome Project.

  9. Dental implants installed in irradiated jaws: a systematic review.

    PubMed

    Chambrone, L; Mandia, J; Shibli, J A; Romito, G A; Abrahao, M

    2013-12-01

    The aim of this study was to assess the survival rate of titanium implants placed in irradiated jaws. MEDLINE, EMBASE, and CENTRAL were searched for studies assessing implants that had been placed in nongrafted sites of irradiated patients. Random effects meta-analyses assessed implant loss in irradiated versus nonirradiated patients and in irradiated patients treated with hyperbaric oxygen (HBO) therapy. Of 1,051 potentially eligible publications, 15 were included. A total of 10,150 implants were assessed in the included studies, and of these, 1,689 (14.3%) had been placed in irradiated jaws. The mean survival rate in the studies ranged from 46.3% to 98.0%. The pooled estimates indicated a significant increase in the risk of implant failure in irradiated patients (risk ratio: 2.74; 95% confidence interval: 1.86, 4.05; p < .00001) and in maxillary sites (risk ratio: 5.96; 95% confidence interval: 2.71, 13.12; p < .00001). Conversely, HBO therapy did not reduce the risk of implant failure (risk ratio: 1.28; 95% confidence interval: 0.19, 8.82; p = .80). Radiotherapy was linked to higher implant failure in the maxilla, and HBO therapy did not improve implant survival. Most included publications reported data on machined implants, and only 3 studies on HBO therapy were included. Overall, implant therapy appears to be a viable treatment option for reestablishing adequate occlusion and masticatory conditions in irradiated patients.

  10. Physiologic Development of Tongue-Jaw Coordination from Childhood to Adulthood

    ERIC Educational Resources Information Center

    Cheng, Hei Yan; Murdoch, Bruce E.; Goozee, Justine V.; Scott, Dion

    2007-01-01

    Purpose: This investigation aimed to examine the development of tongue-jaw coordination during speech from childhood to adolescence. Method: Electromagnetic articulography was used to track tongue and jaw motion in 48 children and adults (aged 6-38 years) during productions of /t/ and /k/ embedded in sentences. Results: The coordinative…

  11. Exploring gradients of halogens and zinc in the surface and subsurface of Nereis jaws.

    PubMed

    Khan, Rashda K; Stoimenov, Peter K; Mates, Thomas E; Waite, J Herbert; Stucky, Galen D

    2006-09-26

    The outstanding mechanical properties of impact-bearing tissues, such as Nereis jaws, make their morphology and chemical composition a subject of particular interest. The complex structure of the jaw was recently reported to exhibit molecular gradients that were closely correlated with stiffness and hardness.(18) Accordingly, we have explored the spatial distribution and bonding chemistries of Zn and the halogens in the surface structure of the jaws. Using secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM), we found that Cl, Br, and I distributions are enhanced in surface layers of the basal protected portion of the jaw but are shifted to greater depths toward the exposed jaw tip. There are thus two complementary halogen gradients in the jaw: one on the surface that decreases from the base to the tip, coupled to an increasing one in the subsurface layers. The outer surface coating appeared to have granular morphology, in contrast to the anisotropic, fibrous core that dominates the subarchitecture. Using X-ray photoelectron spectroscopy (XPS), we discovered that Zn, I, and Br in the jaws have single chemical environments whereas chlorine is present in two distinct modes (Cl-Zn and Cl-C). Given the inverse relationship between surface exposure and halogen abundance in the jaws, it is unlikely that the halogens contribute directly to mechanical properties such as wear and hardness.

  12. [Problems of an infectious jaw cyst in the mixed dentition. Case report].

    PubMed

    Bernhoft, C H

    1978-06-01

    The article describes the complicated treatment of a jaw cyst, caused by an infected temporary tooth. The genesis and the clinical characteristics of jaw cysts in young patients, as well as the importance of due time extraction of the strongly ruined temporary teeth is discussed.

  13. The Speech Focus Position Effect on Jaw-Finger Coordination in a Pointing Task

    ERIC Educational Resources Information Center

    Rochet-Capellan, Amelie; Laboissiere, Rafael; Galvan, Arturo; Schwartz, Jean-Luc

    2008-01-01

    Purpose: This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a 'CVCV (e.g., /'papa/) versus CV'CV (e.g., /pa'pa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the…

  14. Electronic speckle-pattern interferometry (ESPI) applied to the study of mechanical behavior of human jaws

    NASA Astrophysics Data System (ADS)

    Roman, Juan F.; Moreno de las Cuevas, Vincente; Salgueiro, Jose R.; Suarez, David; Fernandez, Paula; Gallas, Mercedes; Blanchard, Alain

    1996-01-01

    The study of the mechanical behavior of the human jaw during chewing is helpful in several specific medical fields that cover the maxillo-facial area. In this work, electronic speckle pattern interferometry has been applied to study dead jaw bones under external stress which simulates the deformations induced during chewing. Fringes obtained after subtraction of two images of the jaw, the image of the relaxed jaw and that of the jaw under stress, give us information about the most stressed zones. The interferometric analysis proposed here is attractive as it can be done in real time with the jaw under progressive stress. Image processing can be applied for improving the quality of fringes. This research can be of help in orthognathic surgery, for example in diagnosis and treatment of fractured jaws, in oral surgery, and in orthodontics because it would help us to know the stress dispersion when we insert an osseointegrated implant or place an orthodontic appliance, respectively. Studying fragments of human jaw some results about its elasticity and flexibility were obtained.

  15. The Effect of Jaw Position on Measures of Tongue Strength and Endurance

    ERIC Educational Resources Information Center

    Solomon, Nancy Pearl; Munson, Benjamin

    2004-01-01

    Assessment of tongue strength and endurance is common in research and clinical contexts. It is unclear whether the results reveal discrete function by the tongue or combined abilities of the tongue and jaw. One way to isolate the movement of the tongue is to constrain the jaw kinematically by using a bite block. In this study, 10 neurologically…

  16. Prevalence of Loss of All Teeth (Edentulism) and Associated Factors in Older Adults in China, Ghana, India, Mexico, Russia and South Africa †

    PubMed Central

    Peltzer, Karl; Hewlett, Sandra; Yawson, Alfred E.; Moynihan, Paula; Preet, Raman; Wu, Fan; Guo, Godfrey; Arokiasamy, Perianayagam; Snodgrass, James J.; Chatterji, Somnath; Engelstad, Mark E.; Kowal, Paul

    2014-01-01

    Little information exists about the loss of all one’s teeth (edentulism) among older adults in low- and middle-income countries. This study examines the prevalence of edentulism and associated factors among older adults in a cross-sectional study across six such countries. Data from the World Health Organization (WHO’s) Study on global AGEing and adult health (SAGE) Wave 1 was used for this study with adults aged 50-plus from China (N = 13,367), Ghana (N = 4724), India (N = 7150), Mexico (N = 2315), Russian Federation (N = 3938) and South Africa (N = 3840). Multivariate regression was used to assess predictors of edentulism. The overall prevalence of edentulism was 11.7% in the six countries, with India, Mexico, and Russia has higher prevalence rates (16.3%–21.7%) than China, Ghana, and South Africa (3.0%–9.0%). In multivariate logistic analysis sociodemographic factors (older age, lower education), chronic conditions (arthritis, asthma), health risk behaviour (former daily tobacco use, inadequate fruits and vegetable consumption) and other health related variables (functional disability and low social cohesion) were associated with edentulism. The national estimates and identified factors associated with edentulism among older adults across the six countries helps to identify areas for further exploration and targets for intervention. PMID:25361046

  17. Convergence in morphology and masticatory function between the pharyngeal jaws of grass carp, Ctenopharyngodon idella, and oral jaws of amniote herbivores.

    PubMed

    Gidmark, Nicholas J; Tarrant, James C; Brainerd, Elizabeth L

    2014-06-01

    The cellulose-rich walls that protect plant cells are difficult to digest, and therefore mechanical food processing is a key aspect of herbivory across vertebrates. Cell walls are typically broken down by translation of flattened teeth in the occlusal plane (i.e. grinding) as part of a complex, rhythmic chewing stroke. The grass carp, Ctenopharyngodon idella, is a voracious, invasive herbivorous fish that relies solely on its pharyngeal teeth, located in the back of the throat, for mechanical processing of plant material. Here, we describe the musculoskeletal anatomy of the pharyngeal jaws of grass carp and use XROMM to quantify chewing kinematics and muscle strain. The pharyngeal jaws are suspended in a sling of 11 muscles and maintain no bony articulation with any other skeletal elements in the head. The jaws bear long, serrated teeth that are worn during use into flattened tooth cusps. Our kinematic data show that this wear is the result of the teeth being elevated into occlusion against the basioccipital process and keratinous chewing pad, not tooth-on-tooth occlusion. Pharyngeal jaw elevation results from large strains in the jaw elevator muscle, the levator arcus branchialis V, to drive a pulley-like mechanism that rotates the jaws about a pivot point at the symphysis between the left and right pharyngeal jaws. These complex, rhythmic jaw rotations translate the teeth laterally across the chewing surface throughout the occlusion phase. The grass carp chewing system is strikingly similar in gross morphology and masticatory function to herbivorous chewing strategies in other vertebrates.

  18. Development of 4D jaw movement visualization system for dental diagnosis support

    NASA Astrophysics Data System (ADS)

    Aoki, Yoshimitsu; Terajima, Masahiko; Nakasima, Akihiko

    2004-10-01

    A person with an asymmetric morphology of maxillofacial skeleton reportedly possesses an asymmetric jaw function and the risk to express temporomandibular disorder is high. A comprehensive analysis from the point of view of both the morphology and the function such as maxillofacial or temporomandibular joint morphology, dental occlusion, and features of mandibular movement pathways is essential. In this study, the 4D jaw movement visualization system was developed to visually understand the characteristic jaw movement, 3D maxillofacial skeleton structure, and the alignment of the upper and lower teeth of a patient. For this purpose, the 3D reconstructed images of the cranial and mandibular bones, obtained by computed tomography, were measured using a non-contact 3D measuring device, and the obtained morphological images of teeth model were integrated and activated on the 6 DOF jaw movement data. This system was experimentally applied and visualized in a jaw deformity patient and its usability as a clinical diagnostic support system was verified.

  19. Requirement for frzb and fzd7a in cranial neural crest convergence and extension mechanisms during zebrafish palate and jaw morphogenesis.

    PubMed

    Kamel, George; Hoyos, Tatiana; Rochard, Lucie; Dougherty, Max; Kong, Yawei; Tse, William; Shubinets, Valeriy; Grimaldi, Michael; Liao, Eric C

    2013-09-15

    Regulation of convergence and extension by wnt-frizzled signaling is a common theme in embryogenesis. This study examines the functional requirements of frzb and fzd7a in convergence and extension mechanisms during craniofacial development. Using a morpholino knockdown approach, we found that frzb and fzd7a are dispensable for directed migration of the bilateral trabeculae, but necessary for the convergence and extension of the palatal elements, where the extension process is mediated by chondrocyte proliferation, morphologic change and intercalation. In contrast, frzb and fzd7a are required for convergence of the mandibular prominences, where knockdown of either frzb or fzd7a resulted in complete loss of lower jaw structures. Further, we found that bapx1 was specifically downregulated in the wnt9a/frzb/fzd7a morphants, while general neural crest markers were unaffected. In addition, expression of wnt9a and frzb was also absent in the edn-/- mutant. Notably, over-expression of bapx1 was sufficient to partially rescue mandibular elements in the wnt9a/frzb/fzd7a morphants, demonstrating genetic epistasis of bapx1 acting downstream of edn1 and wnt9a/frzb/fzd7a in lower jaw development. This study underscores the important role of wnt-frizzled signaling in convergence and extension in palate and craniofacial morphogenesis, distinct regulation of upper vs. lower jaw structures, and integration of wnt-frizzled with endothelin signaling to coordinate shaping of the facial form.

  20. Transition from a fixed implant dental prosthesis to an implant overdenture in an edentulous patient: a clinical report.

    PubMed

    Ali, Bolouri; Bhavani, Venkatachalam

    2014-09-01

    The lack of planning before implant placement and restoration in edentulous patients can lead to a number of problems. Prosthodontists are often faced with the challenge of re-treating patients who have only recently been treated. Although many reports discuss retreatment by fabricating all new prosthetic components, few discuss salvaging parts of the patient's existing prosthesis. This report details the treatment of an edentulous patient who presented with an implant-retained fixed dental prosthesis in the maxillary arch and no opposing prosthesis. The transition from an implant-retained fixed dental prosthesis to a removable implant- and tissue-supported overdenture that uses the patient's existing computer-aided design/computer-aided manufacturing milled titanium substructure is described.

  1. Pain and Disability in the Jaw and Neck Region following Whiplash Trauma.

    PubMed

    Häggman-Henrikson, B; Lampa, E; Marklund, S; Wänman, A

    2016-09-01

    The relationship between whiplash trauma and chronic orofacial pain is unclear, especially with regard to the time elapsed from trauma to development of orofacial pain. The aim was to analyze prevalence of jaw pain and disability, as well as the relationship between pain and disability in the jaw and neck regions in the early nonchronic stage after whiplash trauma. In this case-control study, 70 individuals (40 women, 30 men, mean age 35.5 y) who visited an emergency department with neck pain following a car accident were examined within 3 wk of trauma (group 1) and compared with 70 individuals (42 women, 28 men, mean age 33.8 y), who declined to attend a clinical examination but agreed to fill in questionnaires (group 2). The 2 case groups were compared with a matched control group of 70 individuals (42 women, 28 men, mean age 37.6 y) without a history of neck trauma. All participants completed questionnaires regarding jaw pain and dysfunction, rating pain intensity in jaw and neck regions on the Numerical Rating Scale, the Neck Disability Index, and Jaw Disability Checklist. Compared with controls, individuals with a recent whiplash trauma reported more jaw pain and dysfunction. Furthermore, there was a moderate positive correlation between jaw and neck pain ratings for group 1 (r = 0.61, P < 0.0001) and group 2 (r = 0.59, P < 0.0001). In the logistic regression analysis, cases showed higher odds ratios (range, 6.1 to 40.8) for jaw and neck pain and disability compared with controls. Taken together, the results show that individuals with a recent whiplash trauma report more jaw pain and disability compared with controls without a history of neck trauma. Furthermore, the correlation between jaw and neck pain intensity implies that intensity of neck pain in the acute stage after whiplash trauma might be a possible risk factor also for development of chronic orofacial pain. PMID:27307051

  2. Capture of Prey, Feeding, and Functional Anatomy of the Jaws in Velvet Worms (Onychophora).

    PubMed

    Mayer, Georg; Oliveira, Ivo S; Baer, Alexander; Hammel, Jörg U; Gallant, James; Hochberg, Rick

    2015-08-01

    Onychophorans are carnivorous, terrestrial invertebrates that occur in tropical and temperate forests of the Southern Hemisphere and around the Equator. Together with tardigrades, onychophorans are regarded as one of the closest relatives of arthropods. One of the most peculiar features of onychophorans is their hunting and feeding behavior. These animals secrete a sticky slime, which is ejected via a pair of slime-papillae, to entangle the prey. After the prey has been immobilized, its cuticle is punctured using a pair of jaws located within the mouth. These jaws constitute internalized appendages of the second body segment and are innervated by the deutocerebrum; thus, they are homologous to the chelicerae of chelicerates, and to the (first) antennae of myriapods, crustaceans, and insects. The jaws are also serial homologs of the paired claws associated with each walking limb of the trunk. The structure of the jaws is similar in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Each jaw is characterized by an outer and an inner blade; while the outer blade consists only of a large principal tooth and up to three accessory teeth, the inner blade bears numerous additional denticles. These denticles are separated from the remaining part of the inner jaw by a diastema and a soft membrane only in peripatids. The onychophoran jaws are associated with large apodemes and specialized muscles that enable their movement. In contrast to the mandibles of arthropods, the onychophoran jaws are moved along, rather than perpendicular to, the main axis of the body. Our elemental analysis reveals an increased incorporation of calcium at the tip of each blade, which might provide rigidity, whereas there is no evidence for incorporation of metal or prominent mineralization. Stability of the jaw might be further facilitated by the cone-in-cone organization of its cuticle, as each blade consists of several stacked, cuticular elements. In this

  3. Capture of Prey, Feeding, and Functional Anatomy of the Jaws in Velvet Worms (Onychophora).

    PubMed

    Mayer, Georg; Oliveira, Ivo S; Baer, Alexander; Hammel, Jörg U; Gallant, James; Hochberg, Rick

    2015-08-01

    Onychophorans are carnivorous, terrestrial invertebrates that occur in tropical and temperate forests of the Southern Hemisphere and around the Equator. Together with tardigrades, onychophorans are regarded as one of the closest relatives of arthropods. One of the most peculiar features of onychophorans is their hunting and feeding behavior. These animals secrete a sticky slime, which is ejected via a pair of slime-papillae, to entangle the prey. After the prey has been immobilized, its cuticle is punctured using a pair of jaws located within the mouth. These jaws constitute internalized appendages of the second body segment and are innervated by the deutocerebrum; thus, they are homologous to the chelicerae of chelicerates, and to the (first) antennae of myriapods, crustaceans, and insects. The jaws are also serial homologs of the paired claws associated with each walking limb of the trunk. The structure of the jaws is similar in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Each jaw is characterized by an outer and an inner blade; while the outer blade consists only of a large principal tooth and up to three accessory teeth, the inner blade bears numerous additional denticles. These denticles are separated from the remaining part of the inner jaw by a diastema and a soft membrane only in peripatids. The onychophoran jaws are associated with large apodemes and specialized muscles that enable their movement. In contrast to the mandibles of arthropods, the onychophoran jaws are moved along, rather than perpendicular to, the main axis of the body. Our elemental analysis reveals an increased incorporation of calcium at the tip of each blade, which might provide rigidity, whereas there is no evidence for incorporation of metal or prominent mineralization. Stability of the jaw might be further facilitated by the cone-in-cone organization of its cuticle, as each blade consists of several stacked, cuticular elements. In this

  4. Esthetic considerations for the treatment of the edentulous maxilla based on current informatic alternatives: a case report.

    PubMed

    Rodríguez-Tizcareño, Mario H; Barajas, Lizbeth; Pérez-Gásque, Marisol; Gómez, Salvador

    2012-06-01

    This report presents a protocol used to transfer the virtual treatment plan data to the surgical and prosthetic reality and its clinical application, bone site augmentation with computer-custom milled bovine bone graft blocks to their ideal architecture form, implant insertion based on image-guided stent fabrication, and the restorative manufacturing process through computed tomography-based software programs and navigation systems and the computer-aided design and manufacturing techniques for the treatment of the edentulous maxilla. PMID:22856036

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

    PubMed Central

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

    2014-01-01

    Aim: 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. Materials and Methods: 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. Results: 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. Conclusion: 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. PMID:25210267

  6. "Pseudoconditioned" jaw movements of the rabbit reflect associations conditioned to contextual background cues.

    PubMed

    Sheafor, P J

    1975-07-01

    Two experiments employing 180 rabbits and involving tone conditioned stimuli (CSs) and intraoral water unconditioned stimuli (UCSs) investigated pseudoconditioning of jaw movement. CS-alone, UCS-alone, paired CS-UCS, and four explicitly unpaired CS-UCS treatments were compared to no stimulus presentation. UCS-alone presentations were sufficient to produce pseudo-CR (conditioned response) acquisition. Pseudo-CRs were retained and gradually extinguished over 30 days of CS-alone presentations. Random sequences of unpaired CSc and UCSs produced higher pseudo-CR frequencies than fixed sequences. A pseudo-CR partial reinforcement extinction effect was observed. Background extinction, that is, simply confining the subject in the experimental environment without stimulation, was effective in extinguishing both pseudo-CRs and CRs. Pseudo-CR results could not be attributed to CS-UCS trace conditioning, sensory preconditioning, second-order conditioning, or intra-analyzer conditioning. Results indicate that the associative mechanisms underlying pseudoconditioning phenomena involve conditioning of associations to contextual background (apparatus, trace, temporal, and sequential aftereffect) cues by UCS-alone and unpaired UCS presentations.

  7. Jaw osteonecrosis related to bisphosphonate therapy: a severe secondary disorder.

    PubMed

    Dannemann, C; Grätz, K W; Riener, M O; Zwahlen, R A

    2007-04-01

    Bisphosphonate-related osteonecrosis of the jaws (BON), first described in 2003, is gaining importance due to the increasing indication spectrum of bisphosphonate therapy [S. Takeyama, M. Ito, H. Shinoda, A novel bisphosphonate, TRK-530, for periodontitis, Bone 38 (2006) 31-31; M. Tagil, A. W-Dahl, J. Astrand, D. Little, S. Toksvig-Larsen, Decreasing the catabolic response by a single bisphosphonate infusion shortens the healing time in hemicallotasis operations, Bone 38 (2006) 84-85; E. Rodriguez, M.C. Duran, L.M. Rodriguez, R. Ros, M.R. Aleman, M. Rodriguez-Gaspar, A.M. Lopez, E. Garcia-Valdecasas, F. Santolaria, Intravenous (IV) bisphosphonates for osteopenic cancer survivor women: an alternative treatment, Bone 38 (2006) 72-73; D.G. Little, K. Ward, P. Kiely, M.C. Bellemore, J. Briody, C.T. Cowell, Bisphosphonate rescue in distraction osteogenesis: a case series, Bone 38 (2006) 80-80; R. Marx, Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing epidemic, J. Oral Maxillofac. Surg. 61 (2003) 1115-1118]. BON patients suffering from varying bony defects and symptoms are extremely restricted in their quality of life. Due to a limited knowledge of the aetiology of BON efficient evidence-based treatment strategies are lacking. Until now 23 patients with bisphosphonate-related osteonecrosis have been admitted to the Department of Cranio-Maxillofacial Surgery of the University of Zurich. A complete history has been recorded. All patients underwent clinical and radiographic examination. CT scans and MRI have been performed in selected cases. All patients had in common that, before signs of BON were observed, a local traumatic incidence had occurred. All patients showed signs of infection which could be remarkably reduced by antibacterial treatment. Furthermore, the period of bisphosphonate treatment was found to be one of the significant factors causing bisphosphonate-related osteonecrosis of the jaws. The aetiology of BON

  8. Revisiting de Beer’s textbook example of heterochrony and jaw elongation in fish: calmodulin expression reflects heterochronic growth, and underlies morphological innovation in the jaws of belonoid fishes

    PubMed Central

    2014-01-01

    Background Heterochronic shifts during ontogeny can result in adaptively important innovations and might be initiated by simple developmental switches. Understanding the nature of these developmental events can provide insights into fundamental molecular mechanisms of evolutionary change. Fishes from the Suborder Belonoidei display a vast array of extreme craniofacial morphologies that appear to have arisen through a series of heterochronic shifts. We performed a molecular heterochrony study, comparing postembryonic jaw development in representatives of the Suborder Belonoidei, the halfbeak Dermogenys pusilla (where the lower jaw is considerably elongated compared to the upper jaw) and the needlefish Belone belone (where both jaws are elongated), to a representative of their sister group the Suborder Adrianichthyoidei, the medaka Oryzias latipes, which has retained the ancestral morphology. Results Early in development, the lower jaw displays accelerated growth both in needlefish and halfbeak compared to medaka, and secondary acceleration of the upper jaw is seen in needlefish later in their development, representing a case of mosaic heterochrony. We identified toothless extensions of the dentaries as innovations of Belonoid fishes and the source of heterochronic growth. The molecular basis of growth heterochronies in the Belonoidei was examined through comparing expression of skeletogenic genes during development of halfbeak and medaka. The calmodulin paralogue calm1 was identified as a potential regulator of jaw length in halfbeak as its expression gradually increases in the lower jaw, but not the upper jaw, in a pattern that matches its outgrowth. Moreover, medaka displays equal expression of calm1 in the upper and lower jaws, consistent with the lack of jaw outgrowth in this species. Conclusions Heterochronic shifts in jaw growth have occurred repeatedly during the evolution of Belonoid fishes and we identify toothless extensions of the dentaries as an

  9. Immediate rehabilitation of the edentulous mandible using Ankylos SynCone telescopic copings and intraoral welding: a pilot study.

    PubMed

    Degidi, Marco; Nardi, Diego; Sighinolfi, Gianluca; Piattelli, Adriano

    2012-12-01

    The aim of this prospective study was to assess the suitability of immediate rehabilitation of the edentulous mandible using SynCone copings and the intraoral welding technique. Patients with an edentulous mandible were fitted with a removable restoration supported by an intraorally welded titanium bar. Copings were connected to their respective SynCone 5-degree abutments and then welded to a titanium bar using an intraoral welding unit. This framework was used to support the definitive restoration, which was delivered on the day of implant placement. Restoration success and survival, implant success, and biologic or technical complications were assessed immediately after surgery and at 6 and 12 months. Twenty-two patients were consecutively treated with 88 immediately loaded implants. No acrylic resin fractures or radiographically detectable alterations of the welded frameworks were present in the 22 restorations delivered. One implant (1.1%) failed 1 month after surgery; all remaining implants (98.9%) were clinically stable at the 12-month follow-up. Within its limitations, this pilot study demonstrated that it is possible to successfully rehabilitate the edentulous mandible on the day of surgery with a definitive restoration supported by an intraorally welded titanium framework and SynCone 5-degree abutments.

  10. Osteonecrosis of the jaw and the role of macrophages.

    PubMed

    Pazianas, Michael

    2011-02-01

    Nitrogen-containing bisphosphonates have been associated with the development of osteonecrosis of the jaws (ONJ), but the lack of reliable epidemiological data and appropriate animal models has restricted our understanding of ONJ pathophysiology and limited its management. The best available information is from histopathologic findings, which implicate bone necrosis and infection, although it is not clear which is primary. However, there are data suggesting that macrophages could well be the central factor in allowing the infection to develop first, followed by local necrosis, which could also account for the development of ONJ in patients treated with denosumab, a human monoclonal antibody to the receptor activator of nuclear factor-κB ligand. This review examines the evidence that macrophages could play a prominent role in development of ONJ and the proposal that it may be more appropriate to view ONJ as a drug and not only a bisphosphonate-related complication.

  11. Osteonecrosis of the jaws and bisphosphonates. Report of three cases.

    PubMed

    Pastor-Zuazaga, Daniel; Garatea-Crelgo, Joaquín; Martino-Gorbea, Raúl; Etayo-Pérez, Amaya; Sebastián-López, Cristina

    2006-01-01

    Bisphosphonates are recently acquiring increasing relevance in the treatment of several diseases. In line with the increased use of these compounds, cases of mandibular osteonecrosis, and to a lesser extent, maxillary osteonecrosis, are being reported. This necrosis is difficult to treat in patients who usually have a previously limited quality of life. A surgical performance carried out by oral and maxillofacial surgeons, stomatologists and odontologists might lead to bone exposure. A treatment based on conservation and as harmless as possible seems to be the most advisable way of acting with these patients in order to minimize the incidence and treat the complications, once the lesions have been ascertained. We report three cases treated in our service of osteonecrosis of the jaws after exodontics. This side effect should be remembered before starting any surgical treatment in these patients.

  12. The innervation of the zebrafish pharyngeal jaws and teeth.

    PubMed

    Crucke, Jeroen; Van de Kelft, Annelore; Huysseune, Ann

    2015-07-01

    Zebrafish (Danio rerio) teeth are increasingly used as a model to study odontogenesis in non-mammalians. Using serial semi-thin section histology and immunohistochemistry, the nerves innervating the pharyngeal jaws and teeth have been identified. The last pair of branchial arches, which are non-gill bearing but which carry the teeth, are innervated by an internal branch of a post-trematic ramus of the vagal nerve. Another, external, branch is probably responsible for the motor innervation of the branchiomeric musculature. Nerve fibres appear in the pulp cavity of the teeth only late during cytodifferentiation, and are therefore likely not involved in early steps of tooth formation. The precise role of the nervous system during continuous tooth replacement remains to be determined. Nonetheless, this study provides the necessary morphological background information to address this question.

  13. Bimaxillary Osteotomy for Jaw Deformity With Facioscapulohumeral Muscular Dystrophy.

    PubMed

    Kawasaki, Takako; Ohba, Seigo; Fujimura, Yuji; Asahina, Izumi

    2016-05-01

    Facioscapulohumeral muscular dystrophy (FSHD) is a subtype of muscular dystrophies which reduces the muscle strength, especially the regions of scapular, shoulder, and upper arms, progressively. According to progressive muscle weakness in FSHD, postoperative stability of patient with FSHD after orthognathic surgery is not reliably acquired same as healthy subjects. A 32-year-old woman with FSHD underwent orthodontic and orthognathic surgical treatment due to jaw deformity. She has been followed up more than 3 years after surgery and acquired skeletal stability. This patient is the first report that showed long-term skeletal stability after orthognathic surgery in patient with FSHD. This patient report suggests that it is possible to apply orthognathic surgical treatment to patients with FSHD. PMID:27054436

  14. Lipids in the walls and contents of jaw cysts.

    PubMed

    Stokke, T

    1976-11-01

    The amount and composition of lipid in 129 walls of jaw cyst and 18 pieces of cyst contents was determined by thin-layer chromatography. The proportions of the fractions (i.e. phospholipid, free cholesterol, cholesteryl ester, triglyceride, free fatty acids) were compared with corresponding values (collected from the literature) from the superficial layers of normal and atherosclerotic aortas. The amounts of total lipid and of the fractions were comparable. Concomitant with an increasing amount of lipid, there was a rise in the ratio: total cholesterol/phospholipid. In the aortic lesions this increase of cholesterol was due to a rise in the fraction of cholesteryl ester. In the cyst material, the increase was due to a rise in the free cholesterol. A possible explanation is discussed.

  15. [Adsorption therapy for acute suppurative periostitis of the jaw].

    PubMed

    Maĭborodin, I V; Liubarskiĭ, M S; Loĭko, E R

    2002-01-01

    Capillaries and tissue leukocyte cytograms in soft gingival tissues were examined by optic microscopy in patients with acute purulent periostitis of the jaws treated by different methods. Disorders in the lymph outflow from gingival tissues were detected, which were due to dilatation of the lymph vessels and interstitial spaces in the mucosal lamina propria and stasis with leukocyte aggregation and purulent clots in the lumina of many lymph vessels. Less pronounced dilatation of interstitial spaces and lymph vessels, higher counts of lymphocytes, monocytes, and macrophages in the tissues of the gingival mucosa lamina propria, observed 2 days after the beginning of adsorption therapy of the subperiosteal abscess cavity, indicate that this therapy is more effective in acute purulent periostitis than traditional treatment.

  16. Bisphosphonate osteonecrosis of the jaw: a historical and contemporary review.

    PubMed

    McLeod, Niall M H; Brennan, Peter A; Ruggiero, Salvatore L

    2012-02-01

    The use of bisphosphonate drugs has been popularised in the late 20th century for the management of many conditions associated with abnormalities of bone turnover, particularly metastatic and haematogenous malignancy and osteopenia. The increase in indications for the use of bisphosphonates was supported by what was thought to be a very good safety profile. However in 2003 cases of osteonecrosis related to the use of bisphosphonates were first described. The pathogenesis, and with this the explanation of why it only appears to affect the maxillofacial skeleton, and the best way of managing this problem remains unknown. In this review we examine the process of identification of this pathology and the development of guidelines from medical societies and professional bodies on the management of patients before commencing bisphosphonate therapy, requiring dental treatment whilst on therapy, or with a diagnosis of bisphosphonate associated osteonecrosis of the jaws.

  17. Apodemes associated with limbs support serial homology of claws and jaws in Onychophora (velvet worms).

    PubMed

    de Sena Oliveira, Ivo; Mayer, Georg

    2013-10-01

    Although the onychophoran jaw blades are believed to be derivatives of foot claws, serial homology of these structures has not been demonstrated. To shed light on the evolutionary origin of the onychophoran jaws, we searched for morphological landmarks and compared the internal and external anatomy of jaws and distal leg portions in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Our data revealed hitherto unknown structures associated with the onychophoran limbs, such as a soft diastemal membrane separating the anterior and posterior portions of the inner jaw blade (present only in Peripatidae), apodemes associated with feet, an eversible dorsal sac at the basis of each foot claw, and a specific arrangement of musculature associated with the sclerotised claws, jaws and their apodemes. Specific correspondences in structure and position of apodemes support serial homology of claws and jaws, suggesting that the onychophoran jaw evolved from the distal portion rather than the entire limb in the last common ancestor of Onychophora. PMID:23922297

  18. Molecular and cellular changes associated with the evolution of novel jaw muscles in parrots.

    PubMed

    Tokita, Masayoshi; Nakayama, Tomoki; Schneider, Richard A; Agata, Kiyokazu

    2013-02-01

    Vertebrates have achieved great evolutionary success due in large part to the anatomical diversification of their jaw complex, which allows them to inhabit almost every ecological niche. While many studies have focused on mechanisms that pattern the jaw skeleton, much remains to be understood about the origins of novelty and diversity in the closely associated musculature. To address this issue, we focused on parrots, which have acquired two anatomically unique jaw muscles: the ethmomandibular and the pseudomasseter. In parrot embryos, we observe distinct and highly derived expression patterns for Scx, Bmp4, Tgfβ2 and Six2 in neural crest-derived mesenchyme destined to form jaw muscle connective tissues. Furthermore, immunohistochemical analysis reveals that cell proliferation is more active in the cells within the jaw muscle than in surrounding connective tissue cells. This biased and differentially regulated mode of cell proliferation in cranial musculoskeletal tissues may allow these unusual jaw muscles to extend towards their new attachment sites. We conclude that the alteration of neural crest-derived connective tissue distribution during development may underlie the spatial changes in jaw musculoskeletal architecture found only in parrots. Thus, parrots provide valuable insights into molecular and cellular mechanisms that may generate evolutionary novelties with functionally adaptive significance.

  19. Biting intentions modulate digastric reflex responses to sudden unloading of the jaw.

    PubMed

    Johansson, Anders S; Pruszynski, J Andrew; Edin, Benoni B; Westberg, Karl-Gunnar

    2014-09-01

    Reflex responses in jaw-opening muscles can be evoked when a brittle object cracks between the teeth and suddenly unloads the jaw. We hypothesized that this reflex response is flexible and, as such, is modulated according to the instructed goal of biting through an object. Study participants performed two different biting tasks when holding a peanut half stacked on a chocolate piece between their incisors. In one task, they were asked to split the peanut half only (single-split task), and in the other task, they were asked to split both the peanut and the chocolate in one action (double-split task). In both tasks, the peanut split evoked a jaw-opening muscle response, quantified from electromyogram (EMG) recordings of the digastric muscle in a window 20-60 ms following peanut split. Consistent with our hypothesis, we found that the jaw-opening muscle response in the single-split trials was about twice the size of the jaw-opening muscle response in the double-split trials. A linear model that predicted the jaw-opening muscle response on a single-trial basis indicated that task settings played a significant role in this modulation but also that the presplit digastric muscle activity contributed to the modulation. These findings demonstrate that, like reflex responses to mechanical perturbations in limb muscles, reflex responses in jaw muscles not only show gain-scaling but also are modulated by subject intent.

  20. Morphology does not predict performance: jaw curvature and prey crushing in durophagous stingrays.

    PubMed

    Kolmann, Matthew A; Crofts, Stephanie B; Dean, Mason N; Summers, Adam P; Lovejoy, Nathan R

    2015-12-01

    All stingrays in the family Myliobatidae are durophagous, consuming bivalves and gastropods, as well as decapod crustaceans. Durophagous rays have rigid jaws, flat teeth that interlock to form pavement-like tooth plates, and large muscles that generate bite forces capable of fracturing stiff biological composites (e.g. mollusk shell). The relative proportion of different prey types in the diet of durophagous rays varies between genera, with some stingray species specializing on particular mollusk taxa, while others are generalists. The tooth plate module provides a curved occlusal surface on which prey is crushed, and this curvature differs significantly among myliobatids. We measured the effect of jaw curvature on prey-crushing success in durophagous stingrays. We milled aluminum replica jaws rendered from computed tomography scans, and crushed live mollusks, three-dimensionally printed gastropod shells, and ceramic tubes with these fabricated jaws. Our analysis of prey items indicate that gastropods were consistently more difficult to crush than bivalves (i.e. were stiffer), but that mussels require the greatest work-to-fracture. We found that replica shells can provide an important proxy for investigations of failure mechanics. We also found little difference in crushing performance between jaw shapes, suggesting that disparate jaws are equally suited for processing different types of shelled prey. Thus, durophagous stingrays exhibit a many-to-one mapping of jaw morphology to mollusk crushing performance. PMID:26567348

  1. Influence of maximum bite force on jaw movement during gummy jelly mastication.

    PubMed

    Kuninori, T; Tomonari, H; Uehara, S; Kitashima, F; Yagi, T; Miyawaki, S

    2014-05-01

    It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication.

  2. Development of a novel articulator that reproduced jaw movement with six-degree-of-freedom.

    PubMed

    Nishigawa, Keisuke; Satsuma, Toyoko; Shigemoto, Shuji; Bando, Eiichi; Nakano, Masanori; Ishida, Osamu

    2007-06-01

    A novel robotic articulator that reproduced a six-degree-of-freedom jaw movement was developed and tested. A precise six-axis micro-positioning stage was employed for this articulator. A high-resolution jaw-tracking device measured the functional jaw movement of the patient and a six-axis micro-positioning stage reproduced recorded jaw movement data. A full veneer crown restoration was fabricated with this articulator system. A working cast was mounted on the positioning stage of the articulator. An occlusal table with soft wax was attached on the cast tooth die, and the jaw movements were reproduced to create a functionally generated path on the occlusal table. The finished occlusal record was used to obtain the wax pattern for the crown. In this subject, no intra-oral occlusal adjustment was necessary for setting the finished full veneer crown. Since this articulator could perform a precise reproduction of the dynamic jaw motion during the functional jaw movement, this system has potential to improve accuracy of the prosthetic teeth occlusion.

  3. The Rise of Jaw Protrusion in Spiny-Rayed Fishes Closes the Gap on Elusive Prey.

    PubMed

    Bellwood, David R; Goatley, Christopher H R; Bellwood, Orpha; Delbarre, Daniel J; Friedman, Matt

    2015-10-19

    Jaw protrusion is one of the most important innovations in vertebrate feeding over the last 400 million years [1, 2]. Protrusion enables a fish to rapidly decrease the distance between itself and its prey [2, 3]. We assessed the evolution and functional implications of jaw protrusion in teleost fish assemblages from shallow coastal seas since the Cretaceous. By examining extant teleost fishes, we identified a robust morphological predictor of jaw protrusion that enabled us to predict the extent of jaw protrusion in fossil fishes. Our analyses revealed increases in both average and maximum jaw protrusion over the last 100 million years, with a progressive increase in the potential impact of fish predation on elusive prey. Over this period, the increase in jaw protrusion was initially driven by a taxonomic restructuring of fish assemblages, with an increase in the proportion of spiny-rayed fishes (Acanthomorpha), followed by an increase in the extent of protrusion within this clade. By increasing the ability of fishes to catch elusive prey [2, 4], jaw protrusion is likely to have fundamentally changed the nature of predator-prey interactions and may have contributed to the success of the spiny-rayed fishes, the dominant fish clade in modern oceans [5]. PMID:26455299

  4. The Rise of Jaw Protrusion in Spiny-Rayed Fishes Closes the Gap on Elusive Prey.

    PubMed

    Bellwood, David R; Goatley, Christopher H R; Bellwood, Orpha; Delbarre, Daniel J; Friedman, Matt

    2015-10-19

    Jaw protrusion is one of the most important innovations in vertebrate feeding over the last 400 million years [1, 2]. Protrusion enables a fish to rapidly decrease the distance between itself and its prey [2, 3]. We assessed the evolution and functional implications of jaw protrusion in teleost fish assemblages from shallow coastal seas since the Cretaceous. By examining extant teleost fishes, we identified a robust morphological predictor of jaw protrusion that enabled us to predict the extent of jaw protrusion in fossil fishes. Our analyses revealed increases in both average and maximum jaw protrusion over the last 100 million years, with a progressive increase in the potential impact of fish predation on elusive prey. Over this period, the increase in jaw protrusion was initially driven by a taxonomic restructuring of fish assemblages, with an increase in the proportion of spiny-rayed fishes (Acanthomorpha), followed by an increase in the extent of protrusion within this clade. By increasing the ability of fishes to catch elusive prey [2, 4], jaw protrusion is likely to have fundamentally changed the nature of predator-prey interactions and may have contributed to the success of the spiny-rayed fishes, the dominant fish clade in modern oceans [5].

  5. Jaw movements in patients with a history of pain: an exploratory study.

    PubMed

    Bhaskaracharya, M; Memon, S M; Whittle, T; Murray, G M

    2015-01-01

    The aims were to determine whether individuals with a past history of pain exhibit (i) altered jaw movement (e.g. reduced amplitude, increased jaw movement variability) in comparison with matched asymptomatic controls, and (ii) correlations between psychological measures (e.g. catastrophising) and altered jaw movement variables. Sixteen participants with a history of trigeminal neuropathic pain (TNP) and 15 age- and gender-matched healthy controls had jaw movements recorded during open/close, free gum chewing and chewing at standardised rates. All completed the Pain Catastrophising Scale (PCS), the Pain Self-Efficacy Questionnaire (PSEQ), and the Depression, Anxiety and Stress Scales (DASS). Velocity and amplitude for open/close and chewing, as well as variability, bias and mean square error for open/close jaw movements were compared between groups. Spearman's rank correlation coefficient was used to relate kinematic variables with psychological variables. Statistical significance: P < 0·05. There were no significant differences in mean jaw velocity and amplitude between the TNP and control groups during the open/close jaw movements or free or standardised chewing. In comparison with control, the TNP participants exhibited significantly greater variability, bias and/or mean square error during slow and/or fast opening, and significantly greater variance in velocity and/or amplitude during free and standardised chewing. There were significant negative correlations between PCS scores and velocity and/or amplitude of free and/or standardised chewing. This exploratory study suggests that individuals with a history of pain have altered patterns of jaw movements in comparison with asymptomatic control participants and that catastrophising may play a role in the manifestation of these altered jaw movements. PMID:25146890

  6. Rehabilitation of Edentulous Atrophic Anterior Mandible – The Role of Vertical Alveolar Distraction Osteogenesis

    PubMed Central

    Rao, Latha P; Sequiera, Joyce; Rao, B H Sripathi; Chandra, Jagadish; Rai, Gunachandra

    2014-01-01

    The rehabilitation of patients with edentulous alveolar ridge is always a challenge, more so in case of a long standing atrophic mandible. Mandible, the largest movable bone in the maxillofacial skeleton is associated with many soft tissue attachments which imparts dislodging forces to prosthesis. In addition to this, the rate of resorption of the mandibular ridge is four times that of the maxilla. These factors make the environment of the mandibular arch less favorable to complete denture stability and retention. An ideal solution would be to augment the atrophic alveolar ridge with native bone of the individual which shall eliminate the possible complications, associated with conventional ridge augmentation procedures. With advent of modern technology, and increased biological understanding, the principles of distraction osteogenesis are increasingly being applied to the craniofacial skeleton and have been found to be a viable option in augmenting the native alveolar bone in the mandible. Here the application of an indigenous stainless steel vertical alveolar distraction device to augment atrophic anterior mandibular ridge is assessed in six patients. PMID:25584344

  7. Residual ridge resorption, lower denture stability and subjective complaints among edentulous individuals.

    PubMed

    Huumonen, S; Haikola, B; Oikarinen, K; Söderholm, A-L; Remes-Lyly, T; Sipilä, K

    2012-05-01

    Residual ridge resorption in the mandible after tooth loss may lead to worsening of complete denture stability and to various subjective complaints. The aim was to evaluate the association between radiologically assessed residual ridge resorption in the mandible, clinically assessed stability of lower complete denture and subjective complaints among elderly denture wearers. The study population consisted of 326 (115 men and 211 women) edentulous subjects aged 60-78years, all of whom were wearing complete dentures in the mandible. Data on subjective complaints were obtained from questionnaires and interviews. Denture stability was assessed clinically. Residual ridge resorption was analysed from panoramic radiographs. The results showed that women were significantly more often satisfied with their lower dentures and reported fewer problems with eating than men. They also had significantly more often residual ridge resorption than men. Among women, residual ridge resorption was significantly associated with poor chewing ability, low satisfaction with dentures and poor denture stability. Among men, residual ridge resorption did not associate with subjective complaints or denture stability. Poor satisfaction with dentures associated significantly with poor denture stability in both genders. In conclusion, these results highlight the importance of denture maintenance treatment. As the extent of residual ridge resorption in the mandible was the most important factor that increased dissatisfaction with lower complete dentures, it is also important to inhibit the progression of resorption by preventing tooth loss or by using implant-retained dentures.

  8. Biomechanical aspects of two different implant-prosthetic concepts for edentulous maxillae.

    PubMed

    Benzing, U R; Gall, H; Weber, H

    1995-01-01

    Two essentially different implant-prosthetic concepts are known for the treatment of edentulous maxillae. One concept propagates a "concentrated" arrangement of four to six implants in the premolar and anterior regions with a fixed cantilever superstructure. An alternative is a "spread-out" implant arrangement of six implants placed in the tuberosity, premolar, and anterior regions. The prosthetic rehabilitation consists of a fixed horseshoe-shaped bar and a removable prosthesis. A cantilever situation is avoided. The biomechanical aspects of these implant-prosthetic concepts were studied with clinical strain-gauge measurements and theoretical three-dimensional analysis using the finite element method. Results revealed that the distribution of bone stresses is more favorable with a spread-out implant arrangement than with a concentrated implant arrangement and cantilever restoration. The resistance to bending of a superstructure has an influence on bone stress concentration that should not be ignored. Stresses are controlled not only by the number or distribution of implants, but also by the material and design of the superstructure. PMID:7744438

  9. Severely Resorbed Edentulous Ridges: A Preventive Prosthodontic Approach – A Case Report

    PubMed Central

    Karnam, Shalini; Basimi, Swapna; Surapaneni, Haragopal; Basapogu, Sreeramulu

    2015-01-01

    As a dentist our main aim should be prevention which not only includes prevention of caries and or periodontal disease but also prevention of residual alveolar bone loss after teeth are extracted. Today with greater stress on preventive measures, the dental profession has expanded this preventive concept into Prosthodontics. Preventive Prosthodontics emphasizes the importance of any procedure that can delay or eliminate the future Prosthodontic problem and stop further progression of oral disease and prevent the loss of remaining tissues. The Residual Ridge Resorption (RRR) is an inevitable consequence of tooth loss and denture wearing. Severe RRR gradually results in increased interarch distance, significant horizontal discrepancy between edentulous ridges, occurrence of flabby displaceable tissues in the denture bearing area and other sequelae. Prosthetic rehabilitation in these patients can be challenging. The conventional complete denture fabrication in such cases may further compound the poor denture bearing ability of the tissues and lead to decreased retention, stability and support which may result in psychological problems and social isolation. This case report emphasizes the importance of preventive concepts in every step of complete denture fabrication to offer a long serviceable prosthesis without any significant complications and compromise. PMID:26557629

  10. Electromyographic Evaluation of the Effect of Lined Dentures on Masticatory Muscle Activity in Edentulous Subjects

    PubMed Central

    Srivastava, Shitij; Gaur, Abhishek; Dupare, Arun; Rastogi, Shiksha; Kamatagi, Laxmikant

    2015-01-01

    Aim The purpose of this study was to examine changes in relative electromyographic (EMG) activities of temporal and masseter muscles after relining the dentures with silicone and acrylic-resin based denture liners. Materials and Methods Conventional complete dentures were fabricated for 20 edentulous patients. One month after completing adjustments of the dentures, electromyography of the masseter and temporalis muscle during maximum intercuspation was recorded. The dentures were then relined with a silicone denture liner and after an adaptation period of one month, were again subjected for electromyographic evaluation. Further, the dentures were relined with acrylic denture liner and subjected to electromyographic evaluation. Data was analysed using Statistical Package for Social Sciences (SPSS) version 15.0. Intergroup comparisons were done using ANOVA followed by post-hoc assessments using Tukey HSD test. Results Mean amplitude and duration with conventional dentures was found to be significantly lower as compared to silicone lined and acrylic lined dentures for all the comparisons. Statistically, no significant difference between silicone lined and acrylic lined dentures was observed for any of the comparisons. Conclusion Within the limitations of this experimental design, it was concluded that relining significantly increases electromyographic activity of the masseter and temporalis muscles. Thus, resulting in an improved biting force, chewing efficiency and masticatory performance. There were no significant differences between silicone and acrylic based denture liners for both electromyographic variables. PMID:26436054

  11. 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. PMID:19647417

  12. Electrical study of jaw and orbicularis oculi reflexes after trigeminal nerve surgery.

    PubMed Central

    Ferguson, I T

    1978-01-01

    Trigeminal nerve ophthalmic and motor division function was assessed clinically and electrically in 32 patients who had undergone various surgical procedures for trigeminal neuralgia. Using known electrophysiological techniques, the orbicularis oculi and jaw reflexes were tested in all subjects. Abnormalities of the orbicularis oculi reflex were anticipated on the basis of ophthalmic division anaesthesia. However, jaw reflex abnormalities appeared in operated cases with no clinical or electromyographic evidence of masseter denervation. These results were unexpected, and imply that the proprioceptive fibres of the jaw reflex are mediated by a sensory and not a motor root as previously believed. Images PMID:690653

  13. Nonodontogenic Cysts of the Jaws and Treatment in the Pediatric Population.

    PubMed

    Jones, Richard Scott; Dillon, Jasjit

    2016-02-01

    Nonodontogenic cysts within the jaws are not a common presentation in the pediatric population. Cysts within the pediatric population tend to be developmental and odontogenic in nature. Although nonodontogenic cysts of the jaws are relatively uncommon, it is imperative the clinician understand their clinical behavior and management because failure to do so can result in increased patient morbidity. The nonodontogenic cysts of the jaws that are most often encountered are the central giant cell granuloma, traumatic bone cavity, aneurysmal bone cyst, nasopalatine duct cyst, and nasolabial cyst. This article reviews common clinical findings, radiographic features, histopathologic features, and current treatments of nonodontogenic cysts.

  14. Multiplanar CT reconstruction of the jaw: a new way for implant diagnostics

    NASA Astrophysics Data System (ADS)

    Gursky, S.; Wittek, Werner; Wilke, Walter; Schulz, H.; Lieberenz, S.

    1990-11-01

    For preoperative planning of dental implantations pictorial representations are required that permit to evaluate the size of teeth holes, size and structure of jaw bones, position of the mandibular channel and of the alveolar nerve. Since normal transaxial. CT images do not meet these requirements special secondary reconstructions adapted to jaw anatomy are necessary: -panoramic secondary cuts The cut line follows jaw curvature and represents a similar view as orthopantomographic pictures. (see Fig.1) -oblique secondary cuts That are plane cuts perpendicular to the panoramic cut line. (see Fig.2)

  15. [Positional accuracy and quality assurance of Backup JAWs required for volumetric modulated arc therapy].

    PubMed

    Tatsumi, Daisaku; Nakada, Ryosei; Ienaga, Akinori; Yomoda, Akane; Inoue, Makoto; Ichida, Takao; Hosono, Masako

    2012-01-01

    The tolerance of the Backup diaphragm (Backup JAW) setting in Elekta linac was specified as 2 mm according to the AAPM TG-142 report. However, the tolerance and the quality assurance procedure for volumetric modulated arc therapy (VMAT) was not provided. This paper describes positional accuracy and quality assurance procedure of the Backup JAWs required for VMAT. It was found that a gap-width error of the Backup JAW by a sliding window test needed to be less than 1.5 mm for prostate VMAT delivery. It was also confirmed that the gap-widths had been maintained with an error of 0.2 mm during the past one year.

  16. Epidemiological Data and Survival Rate of Removable Partial Dentures

    PubMed Central

    Moreno, Amália; Haddad, Marcela Filié; Rocha, Eduardo Passos; Assunção, Wirley Gonçalves; Filho, Humberto Gennari; Santos, Emerson Gomes Dos; Sonego, Mariana Vilela; Santos, Daniela Micheline Dos

    2016-01-01

    Introduction The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. Aim This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. Materials and Methods Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. Results A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. Conclusion The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate. PMID:27437367

  17. Free radicals and SOD activity of jaw cyst. Direct measurement and spin trapping studies by ESR.

    PubMed

    Kimura, H; Simodate, H; Suzuki, M

    1990-01-01

    Free radicals produced in the fluid of jaw cysts were directly measured at room temperature using ESR. With these samples, SOD activity of the cyst fluid was measured by the ESR spin trapping method with DMPO as a trapping agent. Freeze-dried samples of cyst fluid showed a broad ESR signal at g = 2.005. Relative signal intensity of samples from jaw cysts with inflammation was higher than jaw cysts without inflammation. SOD activity of cyst fluid with high viscosity showed higher values than that of cyst fluid with low viscosity. We suggest that free radicals produced in jaw cyst damage tissues while higher SOD activity of cyst fluid play a role in a self-defense mechanism against free radicals.

  18. Spontaneous bisphosphonate-related osteonecrosis of the left hemi-mandible: similarities with phossy jaw.

    PubMed

    Campisi, Giuseppina; Compilato, Domenico; Angelo, Itro; Lo Muzio, Lorenzo; Colella, Giuseppe

    2012-01-01

    Intravenous bisphosphonates (BP) play a key role in the treatment of bone metastases. As a long-term side effects BP, a form of avascular osteonecrosis of the jaw has been reported. Although, invasive oral local procedures are often present in clinical history of patients suffering from bisphosphonates-related osteonecrosis of the jaws (BRONJ), about up to 50% of BRONJ are spontaneous. We report a case of a 68-year-old female with a spontaneous wide bone sequestration of the left mandibular body onset after infusion of zoledronic acid for 18 cycles for osseous metastasis due to metastatic anaplastic thyroidal carcinoma. Surprisingly the clinical aspects of the patient initially reminded us of the famous pathology described in 1899 called phossy jaw. This case is remarkable not only for the spontaneity of the osteonecrosis, but, above all, for the clinical similarity with cases of phossy jaw, described for the first time in the literature, thereby suggesting a potential common pathogenesis.

  19. Comparative ontogeny and phylogeny of the upper jaw skeleton in amniotes.

    PubMed

    Richman, Joy M; Buchtová, Marcela; Boughner, Julia C

    2006-05-01

    The morphology, position, and presence of the upper jaw bones vary greatly across amniote taxa. In this review, we compare the development and anatomy of upper jaw bones from the three living amniote groups: reptiles, birds, and mammals. The study of reptiles is particularly important as comparatively little is known about the embryogenesis of the jaw in this group. Our review covers the ontogeny and phylogeny of membranous bones in the face. The aim is to identify conserved embryonic processes that may exist among the three major amniote groups. Finally, we discuss how temporal and spatial regulation of preosseous condensations and ossification centers can lead to variation in the morphology of amniote upper jaw bones. PMID:16496291

  20. Evolution of anthropoid jaw loading and kinematic patterns.

    PubMed

    Ravosa, M J; Vinyard, C J; Gagnon, M; Islam, S A

    2000-08-01

    Major transformations in the skull and masticatory system characterized the evolution of crown anthropoids. To offer further insight into the phylogenetic and arguably adaptive significance of specific primate mandibular loading and kinematic patterns, allometric analyses of metric parameters linked to masticatory function are performed within and between 47 strepsirhine and 45 recent anthropoid species. When possible, basal anthropoids are considered. These results are subsequently integrated with prior experimental and morphological work on primate skull form. As compared to strepsirhines, crown anthropoids have a vertically longer ascending ramus linked to a glenoid and condyle positioned relatively higher above the occlusal plane. Interestingly, anthropoids and strepsirhines do not exhibit different mean ratios of condylar to glenoid height, which suggests that both clades are similar in their ability to evenly distribute occlusal contacts and perhaps forces along the postcanine teeth. Thus, given the considerable suborder differences in the scaling of both glenoid and condylar height, we argue that much of this variation in jaw-joint height is linked to suborder differences in relative facial height due in turn to increased encephalization, basicranial flexion, and facial kyphosis in anthropoids. Due to a more elongate ascending ramus, anthropoids evince more vertically oriented masseters than like-sized strepsirhines. Having a relatively longer ramus and a more medially displaced lateral pterygoid plate, crown anthropoids exhibit medial pterygoids oriented similar to those of strepsirhines, but with a variably longer lever arm. As anthropoid masseters are less advantageously placed to effect transverse movements/forces, we argue that balancing-side deep-masseter activity underlying a wishboning loading regime serves to increase, or at least maintain, transverse levels of jaw movement and occlusal force at the end of the masticatory power stroke. Crown

  1. Jaw expansive lesions: population incidence and CT dentalscan role

    PubMed Central

    FIASCHETTI, V.; FANUCCI, E.; RASCIONI, M.; OTTRIA, L.; BARLATTANI, A.; SIMONETTI, G.

    2011-01-01

    SUMMARY Aim The aim of the study is to evaluate the incidence of different expansive lesions and the advantages of the clinical employment of Dentalscan to study bones lesions and to establish a common diagnostic path. Materials and methods Since January 2005 to November 2009, 3200 patients, not selected for sex or age, have undergone a CT “Dentalscan” in the department of Diagnostic Imaging, Tor Vergata University Hospital (PTV), a suspect bone pathology was found in 704 of them through the XR-orthopantomograpy (OPT). CT images were obtained with General Electric CT Light Speed multislice. Images were saved in the Advantage Workstation (GE) supported by the “Dentascan” dedicated software and by the 3D software (3D SSD). The protocol was : Slice thickness 1,25 mm, gap 0, matrix 512 × 512, 140 KV and 70 mA. All the lesions were also studied with the dedicated three-dimensional reconstructor 3D SSD. Biopsy for diagnosis was performed on all the lesions, except one (false positive with digital OPT). The technique sensitivity was assessed for two important classes: benign and malignant lesions. Results Through CT Dentascan a detailed evaluation of the jaws lesions and their extension was obtained. 656 patients (93.1 %) out of 704 examined for a suspicious lesion on the orthopantomography had a benign lesion: (127 follicular cysts (18.2 %), 181 radicular cysts (25.1%), 93 non odontogenic cysts (13.2%), 29 fibroma (4.2%), 198 odontomes (28.2%), 24 ameloblastoma (3.6%), 4 brown tumors (0.7%), 47 (6.9%) had malignant lesions: (12 carcinoma (1.7%), 29 metastasis (4.3%), 6 sarcoma (0.8%), 1 Dentascan CT resulted to be negative (1 false positive of digital OPT). The sensitivity of the technique for both groups was 99% for benign lesions and 98% for malign lesions. Conclusions CT Dentascan characteristics suggest to consider these techniques as the gold standard for the evaluation of jaw expansive lesions and the support of surgical planning. PMID:23285385

  2. Static jaw collimation settings to minimize radiation dose to normal brain tissue during stereotactic radiosurgery.

    PubMed

    Han, Eun Young; Zhang, Xin; Yan, Yulong; Sharma, Sunil; Penagaricano, Jose; Moros, Eduardo; Corry, Peter

    2012-01-01

    At the University of Arkansas for Medical Sciences (UAMS) intracranial stereotactic radiosurgery (SRS) is performed by using a linear accelerator with an add-on micromultileaf collimator (mMLC). In our clinical setting, static jaws are automatically adapted to the furthest edge of the mMLC-defined segments with 2-mm (X jaw) and 5-mm (Y jaw) margin and the same jaw values are applied for all beam angles in the treatment planning system. This additional field gap between the static jaws and the mMLC allows additional radiation dose to normal brain tissue. Because a radiosurgery procedure consists of a single high dose to the planning target volume (PTV), reduction of unnecessary dose to normal brain tissue near the PTV is important, particularly for pediatric patients whose brains are still developing or when a critical organ, such as the optic chiasm, is near the PTV. The purpose of this study was to minimize dose to normal brain tissue by allowing minimal static jaw margin around the mMLC-defined fields and different static jaw values for each beam angle or arc. Dose output factors were measured with various static jaw margins and the results were compared with calculated doses in the treatment planning system. Ten patient plans were randomly selected and recalculated with zero static jaw margins without changing other parameters. Changes of PTV coverage, mean dose to predefined normal brain tissue volume adjacent to PTV, and monitor units were compared. It was found that the dose output percentage difference varied from 4.9-1.3% for the maximum static jaw opening vs. static jaw with zero margins. The mean dose to normal brain tissue at risk adjacent to the PTV was reduced by an average of 1.9%, with negligible PTV coverage loss. This dose reduction strategy may be meaningful in terms of late effects of radiation, particularly in pediatric patients. This study generated clinical knowledge and tools to consistently minimize dose to normal brain tissue.

  3. Comparative and developmental functional morphology of the jaws of living and fossil gars (Actinopterygii: Lepisosteidae).

    PubMed

    Kammerer, Christian F; Grande, Lance; Westneat, Mark W

    2006-09-01

    The feeding mechanism of gars (Ginglymodi : Lepisosteidae) is characterized by cranial elevation and lower jaw rotation but minimal cranial kinesis. Gar jaws have numerous, sharply pointed, elongate teeth for capture of evasive prey. Their mandibles range from relatively short to extremely long depending on the species. Jaw length and lever dimensions were hypothesized to affect the biomechanics of force and motion during feeding, according to simple mechanical models of muscles exerting force through first- or third-order levers. A morphometric protocol was used to measure the jaw structure of seven living and five fossil species of gar and these data were used to calculate the mechanical advantage (a measure of force transmission) for both opening and closing of the mandible. Gars were found to possess low mechanical advantage (MA) and high transmission of motion, although gars occupy a range of biomechanical states across the continuum of force vs. velocity transmission. The long-nose gar, Lepisosteus osseus, has one of the lowest jaw closing MAs (0.05) ever measured in fishes. Intraspecific lever mechanics were also calculated for a developmental series (from feeding larvae to adults) of L. osseus and Atractosteus spatula. A characteristic ontogenetic curve in MA of the lower jaw was obtained, with a large decrease in MA between larva and juvenile, followed by a steady increase during adult growth. This curve correlates with a change in prey type, with the small, robust-jawed individuals feeding mainly on crustaceans and insects and the large, long-jawed individuals of all species becoming mainly piscivorous. Principal components analysis of functionally important morphometrics shows that several gar species occupy different regions of functional morphospace. Some fossil gar species are also placed within functional morphospace using this approach. PMID:15593308

  4. Insight into the pathogenesis and nature of Central giant cell lesions of the jaws

    PubMed Central

    2015-01-01

    Central giant cell lesions of the jaws are not uncommon. While the majority of these represent single, sporadic lesions, histologically identical lesions are seen in association with a number of other bone lesions, as well as in certain syndromes. This manuscript offers a brief update on recent developments in this area that provide new insight into the pathogenesis and nature of Central Giant Cell Lesions of the Jaws. Key words:Central giant cell lesion, RASopathy PMID:25681371

  5. Zoledronate Effects on Systemic and Jaw Osteopenias in Ovariectomized Periostin-Deficient Mice

    PubMed Central

    Bonnet, Nicolas; Lesclous, Philippe; Saffar, Jean Louis; Ferrari, Serge

    2013-01-01

    Osteoporosis and periodontal disease (PD) are frequently associated in the elderly, both concurring to the loss of jaw alveolar bone and finally of teeth. Bisphosphonates improve alveolar bone loss but have also been associated with osteonecrosis of the jaw (ONJ), particularly using oncological doses of zoledronate. The effects and therapeutic margin of zoledronate on jaw bone therefore remain uncertain. We reappraised the efficacy and safety of Zoledronate (Zol) in ovariectomized (OVX) periostin (Postn)-deficient mice, a unique genetic model of systemic and jaw osteopenia. Compared to vehicle, Zol 1M (100 µg/kg/month) and Zol 1W (100 µg/kg/week) for 3 months both significantly improved femur BMD, trabecular bone volume on tissue volume (BV/TV) and cortical bone volume in both OVX Postn+/+ and Postn−/− (all p<0.01). Zol 1M and Zol 1W also improved jaw alveolar and basal BV/TV, although the highest dose (Zol 1W) was less efficient, particularly in Postn−/−. Zol decreased osteoclast number and bone formation indices, i.e. MAR, MPm/BPm and BFR, independently in Postn−/− and Postn+/+, both in the long bones and in deep jaw alveolar bone, without differences between Zol doses. Zol 1M and Zol 1W did not reactivate inflammation nor increase fibrous tissue in the bone marrow of the jaw, whereas the distance between the root and the enamel of the incisor (DRI) remained high in Postn−/− vs Postn+/+ confirming latent inflammation and lack of crestal alveolar bone. Zol 1W and Zol 1M decreased osteocyte numbers in Postn−/− and Postn+/+ mandible, and Zol 1W increased the number of empty lacunae in Postn−/−, however no areas of necrotic bone were observed. These results demonstrate that zoledronate improves jaw osteopenia and suggest that in Postn−/− mice, zoledronate is not sufficient to induce bone necrosis. PMID:23505553

  6. Plain film and CBCT findings in a case of bisphosphonate-related osteonecrosis of the jaw.

    PubMed

    Singer, Steven R; Mupparapu, Muralidhar

    2009-02-01

    Imaging, along with clinical examination, plays a key role in determining the presence and extent of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, cone-beam computerized tomography (CBCT) was used to detect a large sequestrum and hyperstotic bone, leading to a diagnosis of bisphosphonate-related osteonecrosis of the jaw in a patient with a history of oral bisphosphonate use for treatment of osteoporosis. The radiographic features of this case of BRONJ are discussed.

  7. Evaluation of senior Brazilian dental students about mouth preparation and removable partial denture design.

    PubMed

    Neto, Arcelino Farias; Duarte, Antônio Ricardo Calazans; Shiratori, Fábio Kenji; de Alencar e Silva Leite, Pedro Henrique; Rizzatti-Barbosa, Célia Marisa; Bonachela, Wellington Cardoso

    2010-11-01

    This study aimed to evaluate the knowledge of senior dental students about mouth preparation and removable partial denture (RPD) design. Two hundred sixty-six senior students from eleven dental schools in the State of São Paulo, Brazil, comprised the sample. The subjects examined two partially edentulous casts mounted on a semiadjustable articulator, answered a questionnaire regarding the treatment plan, and drew the RPD design. The casts consisted of Kennedy Class III, modification 1 maxillary arch and Class II mandibular arch. Ninety percent of the students believed that mouth preparation should be performed although no one was able to name all necessary procedures. For the maxillary arch, 12 percent of the denture designs were completely appropriate, 51 percent were partially appropriate, and 37 percent were inappropriate. For the mandibular arch, the results were 3 percent, 40 percent, and 57 percent, respectively.

  8. Role of stag beetle jaw bending and torsion in grip on rivals.

    PubMed

    Goyens, Jana; Dirckx, Joris; Piessen, Maxim; Aerts, Peter

    2016-01-01

    In aggressive battles, the extremely large male stag beetle jaws have to withstand strongly elevated bite forces. We found several adaptations of the male Cyclommatus metallifer jaw morphology for enhanced robustness that conspecific females lack. As a result, males improve their grip on opponents and they maintain their safety factor (5.2-7.2) at the same level as that of females (6.8), despite their strongly elevated bite muscle force (3.9 times stronger). Males have a higher second moment of area and torsion constant than females, owing to an enhanced cross-sectional area and shape. These parameters also increase faster with increasing bending moment towards the jaw base in males than in females. Male jaws are more bending resistant against the bite reaction force than against perpendicular forces (which remain lower in battles). Because of the triangular cross section of the male jaw base, it twists more easily than it bends. This torsional flexibility creates a safety system against overload that, at the same time, secures a firm grip on rivals. We found no structural mechanical function of the large teeth halfway along the male jaws. Therefore, it appears that the main purpose of these teeth is a further improvement of grip on rivals.

  9. Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

    PubMed

    Warburton, Natalie Marina

    2009-06-01

    The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type. The relative mass of the masseter is roughly consistent, but grazers and mixed-feeders (Macropus and Lagostrophus) had relatively larger medial pterygoids and smaller temporalis muscles than the browsers (Dendrolagus, Dorcopsulus, and Setonix). Grazing macropods show similar jaw muscle proportions to "ungulate-grinding" type placental mammals. The internal architecture of the jaw muscles also varies between grazing and browsing macropods, most significantly, the anatomy of the medial pterygoid muscle. Potoroines have distinctly different jaw muscle proportions to macropodines. The masseter muscle group, in particular, the superficial masseter is enlarged, while the temporalis group is relatively reduced. Lagostrophus fasciatus is anatomically distinct from other macropods with respect to its masticatory muscle anatomy, including enlarged superficial medial pterygoid and deep temporalis muscles, an anteriorly inflected masseteric process, and the shape of the mandibular condyle. The enlarged triangular pterygoid process of the sphenoid bone, in particular, is distinctive of Lagsotrophus.

  10. Evolution of muscle activity patterns driving motions of the jaw and hyoid during chewing in Gnathostomes.

    PubMed

    Konow, Nicolai; Herrel, Anthony; Ross, Callum F; Williams, Susan H; German, Rebecca Z; Sanford, Christopher P J; Gintof, Chris

    2011-08-01

    Although chewing has been suggested to be a basal gnathostome trait retained in most major vertebrate lineages, it has not been studied broadly and comparatively across vertebrates. To redress this imbalance, we recorded EMG from muscles powering anteroposterior movement of the hyoid, and dorsoventral movement of the mandibular jaw during chewing. We compared muscle activity patterns (MAP) during chewing in jawed vertebrate taxa belonging to unrelated groups of basal bony fishes and artiodactyl mammals. Our aim was to outline the evolution of coordination in MAP. Comparisons of activity in muscles of the jaw and hyoid that power chewing in closely related artiodactyls using cross-correlation analyses identified reorganizations of jaw and hyoid MAP between herbivores and omnivores. EMG data from basal bony fishes revealed a tighter coordination of jaw and hyoid MAP during chewing than seen in artiodactyls. Across this broad phylogenetic range, there have been major structural reorganizations, including a reduction of the bony hyoid suspension, which is robust in fishes, to the acquisition in a mammalian ancestor of a muscle sling suspending the hyoid. These changes appear to be reflected in a shift in chewing MAP that occurred in an unidentified anamniote stem-lineage. This shift matches observations that, when compared with fishes, the pattern of hyoid motion in tetrapods is reversed and also time-shifted relative to the pattern of jaw movement.

  11. The assessment of lower face morphology changes in edentulous patients after prosthodontic rehabilitation, using two methods of measurement.

    PubMed

    Jivănescu, Anca; Bratu, Dana Cristina; Tomescu, Lucian; Măroiu, Alexandra Cristina; Popa, George; Bratu, Emanuel Adrian

    2015-01-01

    Using two measurement methods (a three-dimensional laser scanning system and a digital caliper), this study compares the lower face morphology of complete edentulous patients, before and after prosthodontic rehabilitation with bimaxillary complete dentures. Fourteen edentulous patients were randomly selected from the Department of Prosthodontics, at the Faculty of Dental Medicine, "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania. The changes that occurred in the lower third of the face after prosthodontic treatment were assessed quantitatively by measuring the vertical projection of the distances between two sets of anthropometric landmarks: Subnasale - cutaneous Pogonion (D1) and Labiale superius - Labiale inferius (D2). A two-way repeated measures ANOVA model design was carried out to test for significant interactions, main effects and differences between the two types of measuring devices and between the initial and final rehabilitation time points. The main effect of the type of measuring device showed no statistically significant differences in the measured distances (p=0.24 for D1 and p=0.39 for D2), between the initial and the final rehabilitation time points. Regarding the main effect of time, there were statistically significant differences in both the measured distances D1 and D2 (p=0.001), between the initial and the final rehabilitation time points. The two methods of measurement were equally reliable in the assessment of lower face morphology changes in edentulous patients after prosthodontic rehabilitation with bimaxillary complete dentures. The differences between the measurements taken before and after prosthodontic rehabilitation proved to be statistically significant.

  12. Comparative Analysis of Salivary Bacterial Microbiome Diversity in Edentulous Infants and Their Mothers or Primary Care Givers Using Pyrosequencing

    PubMed Central

    Cephas, Kimberly D.; Kim, Juhee; Mathai, Rose Ann; Barry, Kathleen A.; Dowd, Scot E.; Meline, Brandon S.; Swanson, Kelly S.

    2011-01-01

    Bacterial contribution to oral disease has been studied in young children, but there is a lack of data addressing the developmental perspective in edentulous infants. Our primary objectives were to use pyrosequencing to phylogenetically characterize the salivary bacterial microbiome of edentulous infants and to make comparisons against their mothers. Saliva samples were collected from 5 edentulous infants (mean age = 4.6±1.2 mo old) and their mothers or primary care givers (mean age = 30.8±9.5 y old). Salivary DNA was extracted, used to generate DNA amplicons of the V4–V6 hypervariable region of the bacterial 16S rDNA gene, and subjected to 454-pyrosequencing. On average, over 80,000 sequences per sample were generated. High bacterial diversity was noted in the saliva of adults [1012 operational taxonomical units (OTU) at 3% divergence] and infants (578 OTU at 3% divergence). Firmicutes, Proteobacteria, Actinobacteria, and Fusobacteria were predominant bacterial phyla present in all samples. A total of 397 bacterial genera were present in our dataset. Of the 28 genera different (P<0.05) between infants and adults, 27 had a greater prevalence in adults. The exception was Streptococcus, which was the predominant genera in infant saliva (62.2% in infants vs. 20.4% in adults; P<0.05). Veillonella, Neisseria, Rothia, Haemophilus, Gemella, Granulicatella, Leptotrichia, and Fusobacterium were also predominant genera in infant samples, while Haemophilus, Neisseria, Veillonella, Fusobacterium, Oribacterium, Rothia, Treponema, and Actinomyces were predominant in adults. Our data demonstrate that although the adult saliva bacterial microbiome had a greater OTU count than infants, a rich bacterial community exists in the infant oral cavity prior to tooth eruption. Streptococcus, Veillonella, and Neisseria are the predominant bacterial genera present in infants. Further research is required to characterize the development of oral microbiota early in life and

  13. Use of larder beetles (Coleoptera: Dermestidae) to deflesh human jaws.

    PubMed

    Charabidze, D; Colard, T; Becart, A; Hedouin, V

    2014-01-01

    We describe new experimental data for the defleshing of human bones using larder beetles (Dermestes haemorrhoidalis) (Küster, 1852). Although the ability of larder beetles to feed on vertebrate remains has been, and still is, used by taxidermists to deflesh skulls and bones, this method has never been documented from a quantitative perspective and has over time become ignored in most forensic anthropology or odontology laboratories. To promote the rational and efficient use of this method, we performed experiments to estimate the quantity of food consumed by larvae. From the 2nd instar to nymphosis, each larva consumed a mean of 0.13±0.03 g of dry beef muscle. We then used 100±50 D. haemorrhoidalis adults and 100±50 larvae to deflesh human maxillae and mandibles sampled within a forensic context (victim identification). Each sample was weighed and photographed before, during and after the experiment. According to our experiments, 20-25 days were sufficient to completely deflesh all of the samples. We concluded that a small number of larder beetles can be used to efficiently deflesh human jaws. According to this result, the use of larder beetles appears to be an inexpensive, simple and efficient way to clean mandibles and maxillae. Furthermore, this method is DNA-safe (compared to usual maceration techniques) and thus allows the samples to be used for subsequent DNA and drug analyses.

  14. Immunocytochemical expression of growth factors by odontogenic jaw cysts.

    PubMed Central

    Li, T.; Browne, R. M.; Matthews, J. B.

    1997-01-01

    AIM: To determine the immunocytochemical pattern of expression of transforming growth factor (TGF) alpha, epidermal growth factor (EGF), and TGF beta in the three most common types of odontogenic jaw cyst. METHODS: Growth factor expression was detected in paraffin wax sections of odontogenic cysts (27 odontogenic keratocysts, 10 dentigerous cysts, and 10 radicular cysts) using a streptavidin-biotin peroxidase technique with monoclonal antibodies directed against TGF alpha (clone 213-4.4) and TGF beta (clone TB21) and a polyclonal antibody directed against EGF (Z-12). RESULTS: The epithelial linings of all cysts showed reactivity for TGF alpha which was mainly localised to basal and suprabasal layers. Odontogenic keratocyst linings expressed higher levels of TGF alpha than those of dentigerous and radicular cysts, with 89% (24/27) of odontogenic keratocysts exhibiting a strong positive reaction compared with 50% (five of 10) of dentigerous and radicular cysts, respectively. EGF reactivity was similar in all cyst groups, weaker than that for TGF alpha and predominantly suprabasal. TGF alpha and EGF were also detected in endothelial cells, fibroblasts and inflammatory cells within the cyst walls. The most intense TGF beta staining in odontogenic cysts was extracellular within the fibrous tissue capsules, irrespective of cyst type. CONCLUSIONS: These results, together with previous studies of EGF receptor, indicate differential expression of TGF alpha, EGF and their common receptor between the different types of odontogenic cyst, suggesting that these growth factors (via autocrine or paracrine, or both, pathways) may be involved in their pathogenesis. Images PMID:9208810

  15. [Osteonecrosis of the jaw and bisphophonates in oncology].

    PubMed

    Facon, Thierry; Bensadoun, René-Jean; Blanc, Jean-Louis; Confavreux, Cyril; Gourmet, René; Maes, Jean-Michel; Penel, Guillaume; Vieillard, Marie-Hélène; Woeller, Anne

    2008-04-01

    Bisphosphonates are potent osteoclastic inhibitors that are indicated in the prevention of bone complications. They could also be of interest in the prevention of bone metastases. Several recent international publications have highlighted the onset of osteonecrosis of the jaw (ONJ) in patients treated with bisphosphonates. These osteonecroses manifest in the form of bone exposure, recent tooth mobility, swelling and inflammation and, occasionally, localised pain but they can remain asymptomatic for weeks or even months. The prevalence of these osteonecroses in cancer patients treated with bisphosphonates could range from 1 to 10%. In most cases (60 to 80%), ONJ develops after alveolo-dental surgery (e.g. tooth extraction). Length of exposure to bisphosphonate probably increases the risk. Our recommendations regarding the diagnosis, classification, prevention and treatment of cases of ONJ observed during bisphosphonate administration are based on published studies and our experience. It is obvious that the use of bisphosphonates is undoubtedly beneficial in the treatment of bone complications but the incidence of ONJ during long-term treatments and at high doses warrants preventive measures. These measures are straightforward : bucco-dental repair prior to treatment, good hygiene and regular monitoring during treatment. Current, non-invasive procedures are still permitted. In other cases, the suspension of treatment is indicated until healing is complete. The increase in the incidence of ONJs, serious adverse events, raises the issue regarding duration and administration of bisphosphonate treatment in the management of bone metastases. Studies are currently underway in an attempt to answer this issue.

  16. Post-traumatic disorders of the jaw joint.

    PubMed Central

    Norman, J. E.

    1982-01-01

    A group of 165 patients with surgical diseases of the temporomandibular joint treated in 3 Australian university hospitals is reviewed. A facial trauma is relatively common patients have been included in the post-traumatic group only if there was an undisputed history of injury requiring medical or dental treatment or admission to hospital. In 38.3% of patients with histologically proven osteoarthritis there was an undisputed history of trauma. In a further group with recurrent mandibular dislocation 62.6% were post-traumatic. Trauma was the cause of 62.5% of cases of mandibular ankylosis. There is a general tendency to underdiagnose degenerative joint disease and to perpetuate conservative treatment when it is crystal clear that these measures are not being successful. It is probable that intracapsular fractures of the jaw joint are frequently undiagnosed and a higher index of suspicion is required. Mandibular ankylosis continues to pose some difficulty of management and a critical review confirms that wide surgical exposure of the joint is essential; the importance of long-term review is stressed. The outcome of the surgical treatment of recurrent luxation is excellent and an operation of commendable simplicity is advocated. Images fig. 5 p34-a PMID:7055365

  17. A precise radiographic method to determine the location of the inferior alveolar canal in the posterior edentulous mandible: implications for dental implants. Part 1: Technique.

    PubMed

    Stella, J P; Tharanon, W

    1990-01-01

    In severely atrophic or osteoporotic mandibles, the location of the inferior alveolar nerve may vary considerably, both superoinferiorly and mediolaterally. A clinician's ability to reliably locate this nerve within the mandible would permit the surgical planning of implant placement in the posterior edentulous mandible. Eight edentulous cadaver mandibles were studied. A technique that precisely locates the inferior alveolar nerve within the mandible is described. The technique will aid the surgeon in planning a surgical approach to the posterior mandible with reduced risk of injury to the inferior alveolar nerve. PMID:2391135

  18. Neural crest-mediated bone resorption is a determinant of species-specific jaw length

    PubMed Central

    Ealba, Erin L.; Jheon, Andrew H.; Hall, Jane; Curantz, Camille; Butcher, Kristin D.; Schneider, Richard A.

    2015-01-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are considered the predominant cells that resorb bone, although osteocytes have also been shown to participate in this process. In adults, bone resorption is tightly coupled to bone deposition as a means to maintain skeletal homeostasis. Yet, the role and regulation of bone resorption during growth of the embryonic skeleton have remained relatively unexplored. We compare jaw development in short-beaked quail versus long-billed duck and find that quail have substantially higher levels of enzymes expressed by bone-resorbing cells including tartrate-resistant acid phosphatase (TRAP), Matrix metalloproteinase 13 (Mmp13), and Mmp9. Then, we transplant NCM destined to form the jaw skeleton from quail to duck and generate chimeras in which osteocytes arise from quail donor NCM and osteoclasts come exclusively from the duck host. Chimeras develop quail-like jaw skeletons coincident with dramatically elevated expression of TRAP, Mmp13, and Mmp9. To test for a link between bone resorption and jaw length, we block resorption using a bisphosphonate, osteoprotegerin protein, or an MMP13 inhibitor, and this significantly lengthens the jaw. Conversely, activating resorption with RANKL protein shortens the jaw. Finally, we find that higher resorption in quail presages their relatively lower adult jaw bone mineral density (BMD) and that BMD is also NCM-mediated. Thus, our experiments suggest that NCM not only controls bone resorption by its own derivatives but also modulates the activity of mesoderm

  19. [Biomechanics of the jaw apparatus in the horn-shark (Heterodontus portusjacksoni = Heterodontus philippi)].

    PubMed

    Nobiling, G

    1977-01-01

    The constructional morphology of the jaw apparatus in the horn-shark Heterodontus has been investigated. The origines and insertions of the jaw muscles have been delimited and the lines of action were determined. The individual muscles have been weighed, in order to get on the basis of their masses an estimate of the forces which are exerted by the components of the jaw musculature. The mandibular joints, the occlusion of the jaws, morphological details of the upper and lower jaws as well as the "subodontium" have been subject to macroscopic and microscopic study. The joint between palatoquadrate and mandibular consists of a medial and a lateral compartment. Only hinge movements are possible. If the jaws are closed, the contacts between upper and lower jaws are confined to the large crushing teeth of only one or two tooth families. The teeth are fixed to the jaw cartilage by ligamentous structures. Three layers can be discerned histologically: The uppermost layer, beneath the bases of the teeth, is composed of the fibrae interdentales and of the fibrae subbasales. By these, the individual teeth are firmly connected to form a continuous pavement. - The middle layer is characterised by the great number of cell nuclei. - The fibre system which constitutes the lowermost layer is arranged according to its function. The subdental layer of fibrous tissue grows faster than the one adjacent to the jaws. Thus a particular growth structure is formed. - Two constructive principles are realised: 1. The biting forces or "loads", applied to one or two teeth, are split and distributed on all teeth of the same family which are lingual of the loaded one. 2. As in the thecodont mammals, the compressive biting (= occlusal) force is transformed into a tensile force by the tooth-fixing apparatus and by the shapes of the jaws and this is sustained by fibrous structures. Magnitude and directions of the stresses which appear in the upper and lower jaw during biting are compared with stress

  20. Resetting of cortically induced rhythmical jaw movements by stimulation of the cerebellar interpositus nucleus in the guinea pig.

    PubMed

    Katayama, T; Kohase, H; Nakamura, Y

    1993-07-16

    Effects of stimulation of the cerebellar interpositus nucleus on fictive rhythmical jaw movements induced by stimulation of the cortical masticatory area were studied in ketamine-anesthetized, paralyzed guinea pigs. A short pulse-train applied to the interpositus nucleus caused a phase shift in cortically induced rhythmical jaw movements. A phase transition curve indicated that interpositus stimulation can reset the cortically induced rhythmical jaw movements.

  1. Morphology and biomechanics of the pinniped jaw: mandibular evolution without mastication.

    PubMed

    Jones, Katrina E; Ruff, Christopher B; Goswami, Anjali

    2013-07-01

    Pinnipeds (seals, sea lions, and walruses) underwent a shift in jaw function away from typical carnivoran mastication to more novel marine behaviors during the terrestrial-aquatic transition. Here we test the effect of aquatic prey capture and male-male combat on the morphological evolution of a mammal jaw that does not masticate. Nine three-dimensional landmarks were taken along the mandible for 25 species (N = 83), and corpus and symphysis external and cortical breadths for a subset of five species (N = 33). Principal components analysis was performed on size-corrected landmark data to assess variation in overall jaw morphology across pinnipeds. Corpus breadths were input to a beam model to calculate strength properties and estimated bite force of specific species with contrasting behaviors (filter feeding, suction feeding, grip-and-tear feeding, and male-male combat). Results indicate that, although phylogenetic signal in jaw shape is strong, function is also important in determining morphology. Filter feeders display an elongate symphysis and a long toothrow that may play a role in filtering krill. Grip-and-tear feeders have a long jaw and large estimated bite force relative to non-biting species. However, the largest estimated bite forces were observed in males of male-male combative species, likely due to the high selection pressure associated with male success in highly polygynous species. The suction feeding jaw is weak in biting but has a different morphology in the two suction feeding taxa. In conclusion, familial patterns of pinniped jaw shape due to phylogenetic relatedness have been modified by adaptations to specialized behavior of individual taxa. PMID:23653179

  2. Morphology and biomechanics of the pinniped jaw: mandibular evolution without mastication.

    PubMed

    Jones, Katrina E; Ruff, Christopher B; Goswami, Anjali

    2013-07-01

    Pinnipeds (seals, sea lions, and walruses) underwent a shift in jaw function away from typical carnivoran mastication to more novel marine behaviors during the terrestrial-aquatic transition. Here we test the effect of aquatic prey capture and male-male combat on the morphological evolution of a mammal jaw that does not masticate. Nine three-dimensional landmarks were taken along the mandible for 25 species (N = 83), and corpus and symphysis external and cortical breadths for a subset of five species (N = 33). Principal components analysis was performed on size-corrected landmark data to assess variation in overall jaw morphology across pinnipeds. Corpus breadths were input to a beam model to calculate strength properties and estimated bite force of specific species with contrasting behaviors (filter feeding, suction feeding, grip-and-tear feeding, and male-male combat). Results indicate that, although phylogenetic signal in jaw shape is strong, function is also important in determining morphology. Filter feeders display an elongate symphysis and a long toothrow that may play a role in filtering krill. Grip-and-tear feeders have a long jaw and large estimated bite force relative to non-biting species. However, the largest estimated bite forces were observed in males of male-male combative species, likely due to the high selection pressure associated with male success in highly polygynous species. The suction feeding jaw is weak in biting but has a different morphology in the two suction feeding taxa. In conclusion, familial patterns of pinniped jaw shape due to phylogenetic relatedness have been modified by adaptations to specialized behavior of individual taxa.

  3. Mechanical analysis on individualized finite element of temporal-mandibular joint under overlarge jaw opening status

    PubMed Central

    Sun, Mingxu; Yang, Jianjun; Zhou, Ruizhi; Li, Ningyi; Xia, Junnan; Gu, Fang

    2015-01-01

    Background: Analyze the stress status of temporal-mandibular joint (TMJ) of a healthy volunteer under the overlarge jaw opening status through the finite element method, with the purpose of clarifying the loading features of each structure in the joint area, and achieving further understanding of the pathogenesis of the temporomandibular disorders (TMD). Methods: Collect the CBCT and MRI data of a volunteer respectively under the maximum jaw opening, establish the finite element model (FEM) of TMJ under the maximum jaw opening status through a series of software, image segmentation, rectification, meshing, material evaluation and other related processing, simulate the mechanical environment of this joint area under this status, and analyze the stress status of the articular disc, condyle cartilage, and condyle process. Results: Based on CT and MRI image data, build 3D model and FEM of TMJ, fully simulate the mechanical environment under the large jaw opening status, and calculate the stress value of the articular disc, condyle process and condylar cartilage. Conclusions: This research result reminds us that the normal people’s articular disc are easy to generate stress concentration under large jaw opening, but its stress is far less than the one under the tight biting status. Perhaps the TMJ symptom induced under the large jaw opening status is mainly caused by the displacement of the articular disc. Under the large jaw opening status, the condylar cartilage plays a vital role in dispersing the stress. This method can be applied for carrying out individualized mechanical analysis on the patients with TMD. PMID:26309558

  4. Morphology and mechanics of the teeth and jaws of white-spotted bamboo sharks (Chiloscyllium plagiosum).

    PubMed

    Ramsay, Jason B; Wilga, Cheryl D

    2007-08-01

    The teeth of white-spotted bamboo sharks (Chiloscyllium plagiosum) are used to clutch soft-bodied prey and crush hard prey; however, the dual function is not evident from tooth morphology alone. Teeth exhibit characteristics that are in agreement with a clutching-type tooth morphology that is well suited for grasping and holding soft-bodied prey, but not for crushing hard prey. The dual role of this single tooth morphology is facilitated by features of the dental ligament and jaw joint. Tooth attachment is flexible and elastic, allowing movement in both sagittal and frontal planes. During prey capture spike-like tooth cusps pierce the flesh of soft prey, thereby preventing escape. When processing prey harder than the teeth can pierce the teeth passively depress, rotating inward towards the oral cavity such that the broader labial faces of the teeth are nearly parallel to the surface of the jaws and form a crushing surface. Movement into the depressed position increases the tooth surface area contacting prey and decreases the total stress applied to the tooth, thereby decreasing the risk of structural failure. This action is aided by a jaw joint that is ventrally offset from the occlusal planes of the jaws. The offset joint position allows many teeth to contact prey simultaneously and orients force vectors at contact points between the jaws and prey in a manner that shears or rolls prey between the jaws during a bite, thus, aiding in processing while reducing forward slip of hard prey from the mouth. Together the teeth, dental ligament, and jaws form an integrated system that may be beneficial to the feeding ecology of C. plagiosum, allowing for a diet that includes prey of varying hardness and elusiveness.

  5. Characterization of interstitial collagenases in jaw cyst wall.

    PubMed

    Teronen, O; Salo, T; Laitinen, J; Törnwall, J; Ylipaavalniemi, P; Konttinen, Y T; Hietanen, J; Sorsa, T

    1995-06-01

    Neutral salt extracts of 14 specimens of jaw cysts were prepared. Histopathological analysis showed that the specimens consisted of 6 radicular cysts, 6 dentigerous cysts, 1 residual cyst, and 1 odontogenic keratocyst. One periapical granuloma, 1 dental follicle and a sample of clinically healthy oral mucosa were similarly processed and used as controls. Measurement of collagenase activity by monitoring the formation of specific degradation products of type I and II collagen in solution by SDS-PAGE demonstrated that all the cyst extracts contained collagenase, some of which was endogenously activated. Cyst wall collagenase preferably degraded type I over type II collagen, which suggests that the degradation was due to MMP-1 (matrix metalloproteinase-1) rather than the MMP-8 type. This was further supported by the doxycycline-inhibition profile of cyst collagenase, which was similar to that of MMP-1. Part of the cyst wall collagenase was in latent proenzyme form and probably derived, at least in part, from the newly synthesized intracellular collagenase pool. Latent cyst collagenase was efficiently activated with phenylmercuric chloride and to a lesser extent by gold (I) thioglucose and NaOCl. Western-blotting, using specific antibodies against collagenase from human polymorphonuclear neutrophilic leukocytes (MMP-8) and from fibroblasts (MMP-1), revealed a typical 55/45 kDa doublet; also MMP-8 in the latent 80 kDa form and fragmented to 65 kDa active species were found. These results suggest the presence of MMP-1 and, to a lesser extent, MMP-8 type collagenase in the cyst wall.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Influence of the Lower Jaw Position on the Running Pattern

    PubMed Central

    Stief, Felix; Jonas, Alexander; Kovac, Andrej; Groneberg, David Alexander; Meurer, Andrea

    2015-01-01

    Introduction The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions. Methods Twenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification. Results Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition. Discussion The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be

  7. The oral microbial community of gingivitis and lumpy jaw in captive macropods.

    PubMed

    Antiabong, John F; Boardman, Wayne; Moore, Robert B; Brown, Melissa H; Ball, Andrew S

    2013-12-01

    Gingivitis and lumpy jaw are diseases of polymicrobial aetiology. Although Fusobacterium necrophorum has been associated with these diseases in macropods, little is known about other organisms associated with these diseases in this animal species. PCR-DGGE analysis revealed the potential pathogens associated with gingivitis and lumpy jaw in macropods. PCR-DGGE profile comparison between the healthy and disease groups indicated a shift in the oral bacterial community structures with similarity coefficients of 48% and 35% for gingivitis and lumpy jaw respectively. Moreover, gingivitis was associated with increase in bacterial diversity (Shannon index = 2.87; PL curve = 45%) while lumpy jaw resulted in a decline in bacterial diversity (Shannon index = 2.47; PL curve = 74%). This study suggest that the establishment of gingivitis and lumpy jaw diseases follows the ecological plaque hypothesis. This forms the basis for an expanded investigation in an epidemiological scale and suggests the need for the appropriate choice of antimicrobial agent(s) and for the effective management and control of polymicrobial diseases.

  8. Actinomyces osteomyelitis in bisphosphonate-related osteonecrosis of the jaw (BRONJ): the missing link?

    PubMed

    De Ceulaer, J; Tacconelli, E; Vandecasteele, S J

    2014-11-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a rare complication of bisphosphonate treatment characterized by the development of exposed, necrotic bone in the jaw with inflammatory signs. The pathogenesis of BRONJ is not yet fully understood. This review analyzes the evidence supporting the hypothesis that BRONJ may be considered as a bisphosphonate-induced Actinomyces infection of the jaw according to the modified Koch's postulates. The main arguments relies on the following factors: (1) the high prevalence of isolation of Actinomyces from bone BRONJ lesions (73.2 % in retrospective series); (2) the similar pathological appearance of BRONJ and Actinomyces osteomyelitis in most studies, although BRONJ lesions without inflammation have been reported; (3) the high incidence of events that disrupt the normal mucosal barrier as a necessary trigger to develop BRONJ in bisphosphonate-exposed patients; (4) the predilection of bisphosphonate-induced osteonecrosis for the bones of the jaws; and (5) the favorable response of BRONJ on treatment that is active on Actinomyces. If BRONJ confirms to be a bisphosphonate-induced Actinomyces osteomyelitis of the jaw, this has major consequences for the prevention and treatment of this condition.

  9. Control of jaw movements in two species of macropodines (Macropus eugenii and Macropus rufus).

    PubMed

    Crompton, A W; Barnet, J; Lieberman, D E; Owerkowicz, T; Skinner, J; Baudinette, R V

    2008-06-01

    The masticatory motor patterns of three tammar wallabies and two red kangaroos were determined by analyzing the pattern of electromyographic (EMG) activity of the jaw adductors and correlating it with lower jaw movements, as recorded by digital video and videoradiography. Transverse jaw movements were limited by the width of the upper incisal arcade. Molars engaged in food breakdown during two distinct occlusal phases characterized by abrupt changes in the direction of working-side hemimandible movement. Separate orthal (Phase I) and transverse (Phase II) trajectories were observed. The working-side lower jaw initially was drawn laterally by the balancing-side medial pterygoid and then orthally by overlapping activity in the balancing- and working-side temporalis and the balancing-side superficial masseter and medial pterygoid. Transverse movement occurred principally via the working-side medial pterygoid and superficial masseter. This pattern contrasted to that of placental herbivores, which are known to break down food when they move the working-side lower jaw transversely along a relatively longer linear path without changing direction during the power stroke. The placental trajectory results from overlapping activity in the working- and balancing-side adductor muscles, suggesting that macropods and placental herbivores have modified the primitive masticatory motor pattern in different ways.

  10. Association between CYP19A1 genotype and pubertal sagittal jaw growth

    PubMed Central

    He, Shushu; Hartsfield, James K.; Guo, Yujiao; Cao, Yang; Wang, Si; Chen, Song

    2016-01-01

    Introduction Sagittal jaw growth is influenced during puberty by a ratio of androgens and estrogens. The CYP19A1 (formerly CYP19) gene encodes the cytochrome P450 enzyme aromatase (estrogen synthetase), which converts testosterone to estrogen. Genetic variations including single nucleotide polymorphisms might regulate CYP19A1 gene expression or the function of the aromatase protein and thus influence sagittal jaw growth. Methods The annual sagittal jaw growth in 92 pubertal orthodontic patients was determined by using pretreatment and posttreatment cephalometric radiographs. Single nucleotide polymorphisms rs2470144 and rs2445761 were genotyped and haplotypes constructed. Associations between genotypes or haplotypes and the annual sagittal growth were estimated by using JMP (version 9.0; SAS Institute, Cary, NC). Results Two single nucleotide polymorphisms were significantly associated with average differences in annual sagittal jaw growth in boys. Haplotype analysis demonstrated that haplotypes Trs2470144Trs2445761 and Crs2470144Trs2445761 had significant effects on annual sagittal maxillary growth and on mandibular growth in boys. No association was found in girls. Conclusions A quantitative trait locus that influences male pubertal sagittal jaw growth might exist in the CYP19A1 gene, and single nucleotide polymorphisms rs2470144 and rs2445761 might be inside this quantitative trait locus or be linked to it. PMID:23116507

  11. A primitive placoderm sheds light on the origin of the jawed vertebrate face.

    PubMed

    Dupret, Vincent; Sanchez, Sophie; Goujet, Daniel; Tafforeau, Paul; Ahlberg, Per E

    2014-03-27

    Extant vertebrates form two clades, the jawless Cyclostomata (lampreys and hagfishes) and the jawed Gnathostomata (all other vertebrates), with contrasting facial architectures. These arise during development from just a few key differences in the growth patterns of the cranial primordia: notably, the nasal sacs and hypophysis originate from a single placode in cyclostomes but from separate placodes in gnathostomes, and infraoptic ectomesenchyme migrates forward either side of the single placode in cyclostomes but between the placodes in gnathostomes. Fossil stem gnathostomes preserve cranial anatomies rich in landmarks that provide proxies for developmental processes and allow the transition from jawless to jawed vertebrates to be broken down into evolutionary steps. Here we use propagation phase contrast synchrotron microtomography to image the cranial anatomy of the primitive placoderm (jawed stem gnathostome) Romundina, and show that it combines jawed vertebrate architecture with cranial and cerebral proportions resembling those of cyclostomes and the galeaspid (jawless stem gnathostome) Shuyu. This combination seems to be primitive for jawed vertebrates, and suggests a decoupling between ectomesenchymal growth trajectory, ectomesenchymal proliferation, and cerebral shape change during the origin of gnathostomes.

  12. Kinematic and Diffusion Tensor Imaging Definition of Familial Marcus Gunn Jaw-Winking Synkinesis

    PubMed Central

    Conte, Antonella; Brancati, Francesco; Garaci, Francesco; Toschi, Nicola; Bologna, Matteo; Fabbrini, Giovanni; Falla, Marika; Dallapiccola, Bruno; Bollero, Patrizio; Floris, Roberto; Berardelli, Alfredo

    2012-01-01

    Background Marcus Gunn jaw-winking synkinesis (MGJWS) is characterized by eyelid ptosis, which disappears during jaw movement. Familial MGJWS is an extremely rare condition. Some authors suggested that MGJWS is due to neural misdirection in the brainstem whereas others suggested that aberrant reinnervation or ephapse may be responsible for synkinetic activity. Pathogenesis of this condition is therefore still unclear. Methodology/Principal Findings To investigate pathogenetic mechanism in familial MGJWS we performed neurophysiological (EMG, Blink Reflex, Recovery cycle of the R2 component of the blink reflex, Masseter inhibitory reflex, BAEPS and kinematic analysis) and neuroradiological (MRI, Diffusion Tensor Imaging) investigations in a member of a multigenerational family with autosomal dominant Marcus Gunn jaw-winking synkinesis (MGJWS). Kinematic analysis of eyelid and jaw movements disclosed a similar onset and offset of the eyelid and jaw in both the opening and closing phases. The excitability of brainstem circuits, as assessed by the blink reflex recovery cycle and recovery index, was normal. Diffusion Tensor Imaging revealed reduced fractional anisotropy within the midbrain tegmentum. Conclusions/Significance Kinematic and MRI findings point to a brainstem structural abnormality in our familial MGJWS patient thus supporting the hypothesis of a neural misdirection of trigeminal motor axons to the elevator palpebralis muscle. PMID:23284759

  13. Alendronate-associated osteonecrosis of the jaws: A review of the main topics

    PubMed Central

    Paiva-Fonseca, Felipe; Santos-Silva, Alan R.; Della-Coletta, Ricardo; Vargas, Pablo A.

    2014-01-01

    Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate, particularly alendronate, has also been reported by a number of authors. Considering that alendronate is one of the most used drugs worldwide, specially for treatment of osteoporosis, a better understanding of osteonecrosis of the jaws related to its use and how to manage these patients is extremely important. Therefore, in the current manuscript the authors aim to review the most important topics related to this pathological presentation. Key words:Bisphosphonates, alendronate, bisphosphonate-related osteonecrosis of the jaws, osteonecrosis. PMID:23986020

  14. Osteonecrosis of the Jaw in Patients Receiving Bone-Targeted Therapies: An Overview--Part I.

    PubMed

    Turner, Bruce; Drudge-Coates, Lawrence; Ali, Sacha; Pati, Jhumur; Nargund, Vinod; Ali, Enamul; Cheng, Leo; Wells, Paula

    2016-01-01

    Urologic patients receiving bone-targeted therapies are at risk of developing osteonecrosis of the jaw (ONJ). ONJ has historically been associated with bisphosphonate therapy. More recently, RANK-Ligand inhibitors (denosumab) have also been used to reduce the risk of skeletal-related events in patients who have advanced cancers with bone metastases. More than 65% of men with metastatic prostate cancer and nearly 75% of women with metastatic breast cancer are affected by bone metastases. The literature has described ONJ associated with bisphosphonate therapy as bisphosphonate-related osteonecrosis of the jaw (BRONJ). However, with evidence also linking the use of RANK-Ligand inhibitors with osteonecrosis of the jaw, we advocate use of the term "anti-bone resorption therapy-related osteonecrosis of the jaw" (ABRT-ONJ). The term "medication-related osteonecrosis of the jaw" (MRONJ) is now becoming more widespread. There is not a universally accepted definition of ABRT-ONJ, which may have hindered recognition and reporting of the condition. In Part I of this article, a review of current knowledge around the etiology of ABRT-ONJ and incidence data are provided. In Part II, we provide an audit of ONJ in a nurse consultant-led bone support clinic. In the article, we refer to zoledronic acid because this is the bisphosphonate of choice for use in men with prostate cancer in the United Kingdom. PMID:27501591

  15. Evolution of the mammalian middle ear and jaw: adaptations and novel structures

    PubMed Central

    Anthwal, Neal; Joshi, Leena; Tucker, Abigail S

    2013-01-01

    Having three ossicles in the middle ear is one of the defining features of mammals. All reptiles and birds have only one middle ear ossicle, the stapes or columella. How these two additional ossicles came to reside and function in the middle ear of mammals has been studied for the last 200 years and represents one of the classic example of how structures can change during evolution to function in new and novel ways. From fossil data, comparative anatomy and developmental biology it is now clear that the two new bones in the mammalian middle ear, the malleus and incus, are homologous to the quadrate and articular, which form the articulation for the upper and lower jaws in non-mammalian jawed vertebrates. The incorporation of the primary jaw joint into the mammalian middle ear was only possible due to the evolution of a new way to articulate the upper and lower jaws, with the formation of the dentary-squamosal joint, or TMJ in humans. The evolution of the three-ossicle ear in mammals is thus intricately connected with the evolution of a novel jaw joint, the two structures evolving together to create the distinctive mammalian skull. PMID:22686855

  16. The oral microbial community of gingivitis and lumpy jaw in captive macropods.

    PubMed

    Antiabong, John F; Boardman, Wayne; Moore, Robert B; Brown, Melissa H; Ball, Andrew S

    2013-12-01

    Gingivitis and lumpy jaw are diseases of polymicrobial aetiology. Although Fusobacterium necrophorum has been associated with these diseases in macropods, little is known about other organisms associated with these diseases in this animal species. PCR-DGGE analysis revealed the potential pathogens associated with gingivitis and lumpy jaw in macropods. PCR-DGGE profile comparison between the healthy and disease groups indicated a shift in the oral bacterial community structures with similarity coefficients of 48% and 35% for gingivitis and lumpy jaw respectively. Moreover, gingivitis was associated with increase in bacterial diversity (Shannon index = 2.87; PL curve = 45%) while lumpy jaw resulted in a decline in bacterial diversity (Shannon index = 2.47; PL curve = 74%). This study suggest that the establishment of gingivitis and lumpy jaw diseases follows the ecological plaque hypothesis. This forms the basis for an expanded investigation in an epidemiological scale and suggests the need for the appropriate choice of antimicrobial agent(s) and for the effective management and control of polymicrobial diseases. PMID:24012349

  17. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc-chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc-chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  18. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc– chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc– chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  19. The Effect of Jaw Position on Measures of Tongue Strength and Endurance

    PubMed Central

    Solomon, Nancy Pearl; Munson, Benjamin

    2012-01-01

    Assessment of tongue strength and endurance is common in research and clinical contexts. It is unclear whether the results reveal discrete function by the tongue or combined abilities of the tongue and jaw. One way to isolate the movement of the tongue is to constrain the jaw kinematically by using a bite block. In this study, 10 neurologically normal young adults performed tongue strength and endurance tasks without a bite block (“jaw-free”) and with bite blocks of various heights (2, 5, 10, and 15 mm for strength; 5 mm for endurance). Data signals included tongue pressure exerted on an air-filled bulb, surface electromyography (SEMG) from the superior tongue blade, and SEMG from 1 masseter. On average, tongue strength (pressure in kPa) was greatest with no bite block and generally decreased as bite blocks increased in height. Pairwise analyses revealed statistically significant differences for all but 3 comparisons (jaw-free to 2 mm, 2 to 5 mm, and 5 to 10 mm). After removing outlying data from 1 participant, tongue endurance at 50% of tongue strength was significantly greater without a bite block than with one. SEMG data did not differ significantly for the strength task across bite block conditions, but inspection of the individual data revealed a tendency for masseter activity to be lower when the jaw was unconstrained. These results suggest that maximal tongue strength and endurance are best assessed with an unconstrained mandible or with a very small bite block. PMID:15212570

  20. A precise radiographic method to determine the location of the inferior alveolar canal in the posterior edentulous mandible: implications for dental implants. Part 2: Clinical application.

    PubMed

    Stella, J P; Tharanon, W

    1990-01-01

    An analysis of implant placement in the posterior region of eight edentulous cadaver mandibles was performed. The results demonstrated that the radiographic technique developed can be employed to safely place implants adjacent to the inferior alveolar nerve in the posterior mandible by using radiographic laminography and a specially designed intraoral reference splint. PMID:2391136

  1. [Bisphosphonate and denosumab-related osteonecrosis of the jaw: Epidemiology, diagnosis and management].

    PubMed

    Dupic, Guillaume; Collangettes, Denise; Dillies, Anne-Françoise; Calvet, Laure; Tournilhac, Olivier; Bay, Jacques-Olivier; Mahammedi, Hakim

    2015-12-01

    Bisphosphonate-related osteonecrosis of the jaw have been widely described. Denosumab has recently been associated to ONJ. Guidance to clinicians is based on criteria established by the American Association of Oral and Maxillofacial Surgeons (AAOMS). Treatment should be multidisciplinary. Two options are available and have to be discussed on the basis of associated therapeutic, patient's general state of health and possibility of therapeutic window during cancer treatment: conservative (medication and conservative surgery like superficial debridement) and extensive surgery. Therefore, we report an update about management strategies of osteonecrosis of the jaw and two cases of patients with a stage 2 osteonecrosis of the jaw only treated with mouth rinses, antibiotics and debridement and complete healing. PMID:26607453

  2. A 3D interactive model and atlas of the jaw musculature of Alligator mississippiensis.

    PubMed

    Holliday, Casey M; Tsai, Henry P; Skiljan, Rebecca J; George, Ian D; Pathan, Sami

    2013-01-01

    Modern imaging and dissemination methods enable morphologists to share complex, three-dimensional (3D) data in ways not previously possible. Here we present a 3D interactive model of the jaw musculature of the American Alligator (Alligator mississippiensis). Alligator and crocodylian jaw musculature is notoriously challenging to inspect and interpret because of the derived nature of the feeding apparatus. Using Iodine-contrast enhanced microCT imaging, a segmented model of jaw muscles, trigeminal nerve, brain and skull are presented as a cross-sectional atlas and 3D, interactive pdf of the rendered model. Modern 3D dissemination methods like this 3D Alligator hold great potential for morphologists to share anatomical information to scientists, educators, and the public in an easily downloadable format. PMID:23762228

  3. Brown tumor at the jaw in patients with secondary hyperparathyroidism due to chronic renal failure.

    PubMed

    Pechalova, Petia F; Poriazova, Elena G

    2013-01-01

    Brown tumors are bony lesions caused by rapid osteoclastic activity, which rare involved jaws. Renal osteodystrophy (ROD) is associated with different pathogenetic mechanisms--disorder of calcium-phosphate metabolism, impaired metabolism of vitamin D, increased parathyroid activity that lead to extreme concentrations of parathormone. The authors report two cases of jaw enlargement in patients received haemodialysis with excessive increase values of alkaline phosphatase and parathormone in serum. The patients were treated surgically with corrective procedures in maxillo-facial area. ROD of the jaws could be severe complication in dialysis patients with end stage of CKD if no appropriate care aimed at correction or prevention of parathyroid hyperfunction was applied to them. PMID:24069663

  4. [Current approaches for early detection and treatment of medication-related osteonecrosis of jaw].

    PubMed

    Janovszky, Ágnes; Vereb, Tamás; Szabó, Andrea; Piffkó, József

    2014-12-01

    Owing to the increased life expectancy, the incidence of rheumatoid disorders and oncologic cases with bone metastasis has dramatically increased. Despite the beneficial effects of the applied antiresorptive and antiangiogenic drugs (e.g. bisphosphonates), serious side effects such as jaw osteonecrosis may also develop. The aim of the authors was to summarize present knowledge about the possibilities of prevention and treatment in medication-related osteonecrosis of the jaw. Based on literature data, currently used detection methods for medication-related osteonecrosis of the jaw (including their advantages and limitations) are summarized. In addition, novel trends of surgical and adjuvant therapeutic approaches are also reviewed. The authors conclude that possibilities of prevention and efficacy of therapeutic interventions in this disorder are still limited possibly due to an incomplete knowledge of the underlying pathomechanism. An interdisciplinary cooperation for prevention and attentive monitoring in order to decrease the incidence of iatrogenic oral and maxillofacial complications seems to be particularly important.

  5. Maximum jaw opening capacity in adolescents in relation to general joint mobility.

    PubMed

    Westling, L; Helkimo, E

    1992-09-01

    Mandibular jaw opening was related with general joint mobility in a non-patient adolescent group. The angular rotation of the mandible at maximum jaw opening was slightly larger in females than in males and significantly larger in hypermobile individuals. No significant relationship between linear measuring of maximal mandibular opening capacity and peripheral joint mobility was found either at active (AROM) or at passive range of mandibular opening (PROM). PROM was strongly correlated to the mandibular length. Clinical signs in the great jaw closer muscles could not be associated to decreased AROM. The mean value of the difference between PROM-AROM (DPA) was 1.2 mm. Frequent clenching and/or grinding was correlated to increased DPA only in hypermobile adolescents (r = 0.49***). Those with DPA exceeding 5mm had all reciprocal clicking.

  6. The relationship between the cranial base and jaw base in a Chinese population

    PubMed Central

    2014-01-01

    Introduction The cranial base plays an important role in determining how the mandible and maxilla relate to each other. This study assessed the relationship between the cranial base and jaw base in a Chinese population. Methods This study involved 83 subjects (male: 27; female: 56; age: 18.4 ± 4.2 SD years) from Hong Kong, who were classified into 3 sagittal discrepancy groups on the basis of their ANB angle. A cephalometric analysis of the angular and linear measurements of their cranial and jaw bases was carried out. The morphological characteristics of the cranial and jaw bases in the three groups were compared and assessments were made as to whether a relationship existed between the cranial base and the jaw base discrepancy. Results Significant differences were found in the cranial base angles of the three groups. Skeletal Class II cases presented with a larger NSBa, whereas skeletal Class III cases presented with a smaller NSBa (P < 0.001). In the linear measurement, skeletal Class III cases presented with a shorter NBa than skeletal Class I and II cases (P < 0.01). There was a correlation between the cranial base angle NSBa and the SNB for the whole sample, (r = -0.523, P < 0.001). Furthermore, correlations between SBaFH and Wits (r = -0.594, P < 0.001) and SBaFH and maxillary length (r = -0.616, P < 0.001) were more obvious in the skeletal Class III cases. Conclusions The cranial base appears to have a certain correlation with the jaw base relationship in a southern Chinese population. The correlation between cranial base and jaw base tends to be closer in skeletal Class III cases. PMID:25129070

  7. SU-E-T-471: Small Field Jaw/MLC Reference Data

    SciTech Connect

    Kerns, J; Alvarez, P; Followill, D; Lowenstein, J; Molineu, A; Summers, P; Kry, S

    2014-06-01

    Purpose: In recent years the need for small field data of MLCs has increased due to the use of intensity-modulated radiation (IMRT), but moreover the use of stereotactic body radiation (SBRT) has increased, which uses not simply small field sizes, but small jaw and field sizes together. Having reference data for these small fields that is reliable would be invaluable to the physics community. Our study has gathered these values and the data distributions from the Radiological Physics Center's (RPC) site visits between 1990 and the present. Methods: For all measurements, the RPC used a 25 × 25 × 25cm water phantom placed at 100cm SSD. All measurements were made with an Exradin A16 cylindrical ion chamber at an effective depth of 10 cm. A total of 42 Varian machine measurements were used to compose the data for a 6 MV beam and 5 TrueBeam 6 MV flattening filter free (FFF) beams were used for FFF data. Results: Jaw/MLC fields were measured for both 6 MV and 6 MF FFF beams with the jaws and MLCs both at the following field sizes: 6×6, 4×4, 3×3, and 2×2cm. Measurements were normalized to the 10×10 field readings (defined by the jaws and MLC). Spread in the data was minimal and demonstrates a high level of accuracy of acquired data. Conclusion: Small field Jaw/MLC reference data for Varian 6MV and 6 MV FFF beams has been analyzed and presented here, composed of the aggregation of numerous RPC site visits. Obtaining reliable small field data remains difficult, however the RPC has collected high fidelity small field Jaw/MLC data. The data are presented as a reference along with their distributions, in such a way that the physicist can act based upon their own desired agreement with the reference data.

  8. "Lumpy jaw" in exotic hoof stock: a histopathologic interpretation with a treatment proposal.

    PubMed

    Fagan, David A; Oosterhuis, James E; Benirschke, Kurt

    2005-03-01

    "Lumpy jaw" of artiodactyls and macropods, although often considered a manifestation of actinomycosis, is actually an osteomyelitis, perhaps commencing with a dental root abscess or trauma to the jaw. Anaerobes may be cultured from the lesions, and vegetable matter may be impacted in them. It is a chronic disease and difficult to treat. Successful treatment may include draining the abscess, cleaning the cavity with saline and antibiotics, flushing with a combination of hydrogen peroxide-sodium hypochlorite and Betadine, and apicoectomy and endodontic filling when active inflammation has subsided.

  9. The role of bisphosphonates in medical oncology and their association with jaw bone necrosis.

    PubMed

    Eid, Ahmed; Atlas, Jennifer

    2014-05-01

    Bisphosphonates, synthetic analogues to inorganic pyrophosphates found in the bone matrix, inhibit bone resorption. Bisphosphonates and their related effects on the jaw have been established since 2001. The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is multifactorial and still under investigation. Currently, drugs with mechanisms of action involving remodeling suppression, osteoclast depression, and decreasing angiogenesis are under investigation for causing BRONJ-like symptoms. Further studies are needed to determine the effective length of use of biphosponates and the efficacy of drug holidays to prevent BRONJ.

  10. Bisphosphonate-related osteonecrosis of the jaw complicated by Ludwig's angina.

    PubMed

    Yang, Rong-Hsin; Shen, Shu-Huei; Li, Wing-Yin; Chu, Yum-Kung

    2015-01-01

    Ludwig's angina is a life-threatening cellulitis that involves the submandibular and sublingual spaces. It often occurs after an infection of the roots of the teeth. However, modern dental care and use of antibiotics for oral infections have made Ludwig's angina rare. We present here a cancer patient exhibiting the sequential features of bisphosphonate related osteonecrosis of the jaw on bone scan complicating with Ludwig's angina. This report highlights the need for medical practitioners to be alert to these rare combinations in the compromised patient after bisphosphonate therapy. To the best of our knowledge, no case of Ludwig's angina secondary to osteonecrosis of the jaw has been reported. PMID:25074798

  11. Jaw cyst-Basal cell nevus-Bifid rib syndrome: a case report.

    PubMed

    Rai, S; Gauba, K

    2007-01-01

    Jaw cyst-Basal cell nevus-Bifid rib syndrome or Gorlin-Goltz syndrome involves multiple organ system. The most common findings include multiple odontogenic keratocysts in the jaws and basal cell nevus on the skin that have an early age onset. These multiple odontogenic keratocysts warrant aggressive treatment at the earliest because of the damage and possible complications associated with them. Recurrence in these lesions is the most characteristic feature that has to be taken in consideration while explaining the prognosis to the patient. A case report of a child affected with Gorlin-Goltz syndrome diagnosed, treated and followed at this hospital is presented here.

  12. Bisphosphonate-related osteonecrosis of the jaw (BRONJ): initial discovery and subsequent development.

    PubMed

    Ruggiero, Salvatore L

    2009-05-01

    The efficacy of bisphosphonates in controlling skeletally related events in cancer patients and fractures in osteoporotic patients coupled with a relatively low level of toxicity and adverse events resulted in a widespread use of these medications in oncology and general internal medicine. However, in early 2001 a relationship had been established between these medications and a new disease entity characterized by necrosis of bone that was isolated to the jaws. This paper will present the chronology of events that led to the discovery of this new complication now known as bisphosphonate-related osteonecrosis of the jaw and review the reaction of professional organizations, the pharmaceutical industry, and government regulators.

  13. Hyperparathyroidism-jaw Tumor Syndrome: An Overlooked Cause of Severe Hypercalcemia.

    PubMed

    Mathews, Joseph Wolfgang; Winchester, Rhonda; Alsaygh, Nebras; Bartlett, Anne M; Luttrell, Louis

    2016-09-01

    Ossifying fibromas of the maxillofacial bones are an uncommon form of benign neoplasm usually treated by surgical excision. Up to 30% of patients with hyperparathyroidism-jaw tumor syndrome, a rare form of multiple endocrine neoplasia resulting from autosomal dominant inactivating mutation of the Hrpt2 tumor suppressor gene, initially present with ossifying fibromas. Coincident hypercalcemia because of the presence of parathyroid adenoma is common in these patients, of whom 15% may have or may develop parathyroid carcinoma. The authors present a case of severe postsurgical hypercalcemia after removal of a large maxillary ossifying fibroma in a patient with previously unrecognized hyperparathyroidism-jaw tumor AU3 syndrome. PMID:27650236

  14. A novel gene mutation in PANK2 in a patient with severe jaw-opening dystonia.

    PubMed

    Yapici, Zuhal; Akcakaya, Nihan Hande; Tekturk, Pinar; Iseri, Sibel Aylin Ugur; Ozbek, Ugur

    2016-09-01

    Pantothenate kinase-associated neurodegeneration (PKAN) is a rare neurodegenerative condition. Major clinical features include progressive dystonia, pigmentary retinopathy, spasticity, and cognitive decline. The typical MRI sign of the disease, known as "eye-of-the-tiger", is what makes differential diagnosis possible. We here describe a 16-year-old male patient with PKAN presenting with severe and sustained jaw-opening dystonia which may be due to heterogeneous etiologies showing poor response to treatment. Herein, long-term follow-up and genetic results of a PKAN case who experienced severe jaw-opening dystonia are presented and discussed. PMID:27185474

  15. Indirect Estimates of Jaw Muscle Tension in Children with Suspected Hypertonia, Children with Suspected Hypotonia, and Matched Controls

    ERIC Educational Resources Information Center

    Connaghan, Kathryn P.; Moore, Christopher A.

    2013-01-01

    Purpose: In this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls. Method: Jaw movement and muscle activation were measured in children (ages 3 years, 11 months, to 10 years) with suspected muscle-tone abnormalities (Down syndrome or…

  16. The Effect of Edentulous Maxillary Impression Tray Designs When Flabby Tissue Is Present: An In Vitro Study.

    PubMed

    Shin, Jae-Ok; Huh, Yoon-Hyuk; Cho, Lee-Ra; Park, Chan-Jin

    2016-01-01

    A model with simulated flabby tissue was fabricated by modifying the standard maxillary edentulous acrylic resin cast to evaluate the effect of maxillary impression tray design on the displacement of flabby tissue. Seven groups of trays were fabricated using different combinations of relief spaces and escape holes. After impression taking, test and control casts were scanned and three-dimensional digital models were superimposed. Negative deviations were recorded at the point of the alveolar crest, the posterior part of the flabby tissue, and the middle of the palate, while positive deviations were recorded at the point of the anterior part of flabby tissue. The amount and characteristics of tissue displacement differed with tray design and the relief method used.

  17. Oral rehabilitation of a patient with bruxism and cluster implant failures in the edentulous maxilla: a clinical report.

    PubMed

    Lin, Wei-Shao; Ercoli, Carlo; Lowenguth, Roxanne; Yerke, Lisa M; Morton, Dean

    2012-07-01

    For most patients with failed dental implants, the placement of new implants is the only option that allows for retreatment with a fixed dental prosthesis. This clinical report describes the rehabilitation of a patient with a history of bruxism and cluster implant failures in the edentulous maxilla 10 years after the insertion of a milled bar overdenture. Seven failed implants were removed and simultaneous bone grafting was performed. After an 8-month healing period, 8 dental implants with new surfaces were placed. These supported a metal ceramic fixed complete denture with a metal occlusal surface. The prosthesis was retained with 3 sections of milled bars and 3 set screws. This clinical report describes the details of the treatment with an emphasis on prosthetics. PMID:22765983

  18. The impact of CBCT imaging when placing dental implants in the anterior edentulous mandible: a before–after study

    PubMed Central

    Ferrero, A; Brunton, P; Goodwin, M; Horner, K

    2015-01-01

    Objectives: To evaluate the impact of CBCT imaging when placing dental implants in the anterior edentulous mandible, using a “before–after” study design. Methods: Eight dental practitioners, who regularly place dental implants in independent dental practice in the North West of England, were presented with realistic simulations of four edentulous cases. The practitioners were asked to assess case difficulty, select implants and then drill osteotomies in preparation for dental implants in the lower canine regions to support a complete overdenture. In the “before” part of the study, a panoramic and a trans-symphyseal view were available. In the “after” part of the study, a CBCT image was added. Perception of case difficulty, implant selection and the incidence of perforations or “near miss perforations” of the lingual cortical plate were recorded. Two cases were regarded as “regular” and two as “challenging”. Results: In challenging cases, the availability of CBCT led practitioners to select narrower implants and to assess cases as more difficult. In the challenging cases only, there were fewer perforations of the lingual cortical plate after the availability of CBCT, but this difference was not statistically significant. There were no perforations in the regular cases either before or after the availability of CBCT. Conclusions: Perception of case difficulty and implant selection are of importance only if they change the outcome for the patient. This study provided weak evidence that CBCT is helpful in avoiding perforations in challenging cases. The availability of CBCT had no impact in regular cases. PMID:25472617

  19. CAD/CAM technologies in the surgical and prosthetic treatment of the edentulous patient with biomymetic individualized approach

    PubMed Central

    POZZI, A.; GARGARI, M.; BARLATTANI, A.

    2008-01-01

    SUMMARY Background: The advent of modern endosseous implant design and improved surface technology has allowed the development of new restorative techniques that decrease patient’s total treatment time. Utilizing the latest scanning, CAD/CAM and manufacturing technolgies we are able to manufacture individualized dental restoration with high accuracy and a perfect precision of fit. Materials and methods: This report describes the rehabilitation of a completely edentulous patient utilizing a CT-based implant planning with computer-assisted surgical design, simultaneous CAD/CAM fabrication of a surgical template, a flapless surgical placement of the implants, and a prefabricated fixed complete denture for an immediately loaded restoration according to Nobel Biocare’s Teeth-in-an-Hour™ (Nobel Biocare Goteborg, Sweden) protocol. This systematic approach to full mouth rehabilitation reduces the time necessary for an edentulous patient to go from severely atrophic alveolar support to implant retained prosthetic restoration. These aspects of minimally invasive and simplified surgery, along with reducing the treatment time and postsurgical discomfort, are beneficial to the patient, and allowing for rehabilitation with the same level of success as in flap surgery. Conclusion: The Teeth-in-an-Hour protocol is a unique solution made possible by the Procera System. With the aid of the CT scans and a virtual planning software, a custom fabricated precision drill guide and a pre-manufactured prosthesis can be made before surgery. The execution of implant placement is performed with a flapless procedure that results in minimal surgical intervention. This results in a short and non-traumatic surgery with a minimum of postoperative complications, allowing the patient to leave the chair with a fixed prosthesis. Utilizing the latest scanning, CAD/CAM and manufacturing technologies the dental team is able to develop individualized zirconia full arch framework with high accuracy

  20. Investigation of Pitch and Jaw Width to Decrease Delivery Time of Helical Tomotherapy Treatments for Head and Neck Cancer

    SciTech Connect

    Moldovan, Monica; Fontenot, Jonas D.; Gibbons, John P.; Lee, Tae Kyu; Rosen, Isaac I.; Fields, Robert S.; Hogstrom, Kenneth R.

    2011-01-01

    Helical tomotherapy plans using a combination of pitch and jaw width settings were developed for 3 patients previously treated for head and neck cancer. Three jaw widths (5, 2.5, and 1 cm) and 4 pitches (0.86, 0.43, 0.287, and 0.215) were used with a (maximum) modulation factor setting of 4. Twelve plans were generated for each patient using an identical optimization procedure (e.g., number of iterations, objective weights, and penalties, etc.), based on recommendations from TomoTherapy (Madison, WI). The plans were compared using isodose plots, dose volume histograms, dose homogeneity indexes, conformity indexes, radiobiological models, and treatment times. Smaller pitches and jaw widths showed better target dose homogeneity and sparing of normal tissue, as expected. However, the treatment time increased inversely proportional to the jaw width, resulting in delivery times of 24 {+-} 1.9 min for the 1-cm jaw width. Although treatment plans produced with the 2.5-cm jaw were dosimetrically superior to plans produced with the 5-cm jaw, subsequent calculations of tumor control probabilities and normal tissue complication probabilities suggest that these differences may not be radiobiologically meaningful. Because treatment plans produced with the 5-cm jaw can be delivered in approximately half the time of plans produced with the 2.5-cm jaw (5.1 {+-} 0.6 min vs. 9.5 {+-} 1.1 min), use of the 5-cm jaw in routine treatment planning may be a viable approach to decreasing treatment delivery times from helical tomotherapy units.

  1. Detection of improvement in the masticatory function from old to new removable partial dentures using mixing ability test.

    PubMed

    Asakawa, A; Fueki, K; Ohyama, T

    2005-09-01

    The aim of this study was to determine the sensitivity of the Mixing Ability Test to detect improvement of masticatory function in subjects on transition from old to new removable partial dentures. Thirty-two subjects (seven males, 25 females, mean age 65.0 years) with distal extension partially edentulous area in mandible and/or maxilla participated in the study. The following reasons were presented for replacing the old removable partial dentures with new ones: fracture and/or poor fitness of retainers, extraction of abutment teeth, poor fitness of denture base, severe wear of artificial teeth and request for metal base dentures. Masticatory function with old and new removable partial dentures after an adaptation period (mean 27.4 weeks) was evaluated by the Mixing Ability Test. Subjects were asked to masticate five two-coloured wax cubes with each removable partial denture. Mixing Ability Index was obtained from the colour mixture and shape of the masticated cubes. Wilcoxon signed-rank test was used to test the difference of Mixing Ability Indexes between old and new removable partial dentures. The mixing ability indexes with new removable partial dentures (mean+/- s.d.: 0.70+/- 0.68) was significantly higher (P<0.001) than those with old removable partial dentures (-0.11+/-1.13). The results suggest that the Mixing Ability Test was capable of detecting improvement in masticatory function with new removable partial dentures.

  2. Embryology of the lamprey and evolution of the vertebrate jaw: insights from molecular and developmental perspectives.

    PubMed Central

    Kuratani, S; Nobusada, Y; Horigome, N; Shigetani, Y

    2001-01-01

    Evolution of the vertebrate jaw has been reviewed and discussed based on the developmental pattern of the Japanese marine lamprey, Lampetra japonica. Though it never forms a jointed jaw apparatus, the L. japonica embryo exhibits the typical embryonic structure as well as the conserved regulatory gene expression patterns of vertebrates. The lamprey therefore shares the phylotype of vertebrates, the conserved embryonic pattern that appears at pharyngula stage, rather than representing an intermediate evolutionary state. Both gnathostomes and lampreys exhibit a tripartite configuration of the rostral-most crest-derived ectomesenchyme, each part occupying an anatomically equivalent site. Differentiated oral structure becomes apparent in post-pharyngula development. Due to the solid nasohypophyseal plate, the post-optic ectomesenchyme of the lamprey fails to grow rostromedially to form the medial nasal septum as in gnathostomes, but forms the upper lip instead. The gnathostome jaw may thus have arisen through a process of ontogenetic repatterning, in which a heterotopic shift of mesenchyme-epithelial relationships would have been involved. Further identification of shifts in tissue interaction and expression of regulatory genes are necessary to describe the evolution of the jaw fully from the standpoint of evolutionary developmental biology. PMID:11604127

  3. Pathological and clinical features of primary osseous tumours of the jaw

    PubMed Central

    Sarkar, Reena

    2014-01-01

    Primary bone tumors of the jaw are rare. The neoplastic cells in these tumors are the osteoblasts and osteoclasts. The gnathic bone tumors have also been referred to as borderline. The clinicopathologic approach towards these bony lesions have been reviewed. PMID:26909304

  4. Bisphosphonate Associated Osteonecrosis of the Jaw: An Update on Pathophysiology, Risk Factors, and Treatment

    PubMed Central

    Rasmusson, Lars

    2014-01-01

    Osteonecrosis of the jaw in patients treated with bisphosphonates is a relatively rare but well known complication at maxillofacial units around the world. It has been speculated that the medication, especially long-term i.v. bisphosphonate treatment, could cause sterile necrosis of the jaws. The aim of this narrative review of the literature was to elaborate on the pathological mechanisms behind the condition and also to gather an update on incidence, risk factors, and treatment of bisphosphonate associated osteonecrosis of the jaw. In total, ninety-one articles were reviewed. All were published in internationally recognized journals with referee systems. We can conclude that necrotic lesions in the jaw seem to be following upon exposure of bone, for example, after tooth extractions, while other interventions like implant placement do not increase the risk of osteonecrosis. Since exposure to the bacterial environment in the oral cavity seems essential for the development of necrotic lesions, we believe that the condition is in fact chronic osteomyelitis and should be treated accordingly. PMID:25254048

  5. Osteomyelitis of the jaw: resistance to clindamycin in patients with prior antibiotics exposure.

    PubMed

    Pigrau, C; Almirante, B; Rodriguez, D; Larrosa, N; Bescos, S; Raspall, G; Pahissa, A

    2009-04-01

    The purpose of this paper was to review our clinical experience in patients with osteomyelitis (OM) of the jaw, focusing on aspects of antimicrobial resistance. A retrospective review of the medical records of adult patients with jaw OM was carried out. Among 46 cases of jaw OM, the cause was odontogenic in 32 (seven had recent dental implants and four bisphosphonate osteonecrosis), postoperative/post-traumatic in eight, and secondary to osteoradionecrosis in six. Clinical features were chronic in 91.3%. The infection was polymicrobial in 24/41 (65.9%). Viridans streptococci were the most commonly isolated agents. Among 26 viridans streptococci tested, 81% were susceptible to penicillin and 96% to fluorquinolones, but only 11.5% to clindamycin. Overall, 35/38 (92.1%) had at least one clindamycin-resistant isolate. Appropriate antibiotics were administered for a mean of 5.8 +/- 3.2 months. Beta-lactams were used in 19 cases and fluorquinolones in 14. Among 39 cases with long-term follow-up, only two relapsed. Currently, jaw OM is commonly related to osteoradionecrosis, dental implants, and bisphosphonates. In patients with prior antibiotics exposure, a high percentage of infections were caused by clindamycin-resistant microorganisms, thus, beta-lactams should be the antibiotic of choice. In penicillin-allergic cases, the new fluorquinolones, probably in combination with rifampin and/or clindamycin, could be a promising alternative.

  6. Re-regeneration of lower jaws and the dental lamina in adult urodeles.

    PubMed

    Graver, H T

    1978-09-01

    Transverse amputations were carried out through one-third fully regenerated jaw segments and through normal tissue of the mandible on the same and opposite sides of the jaw in adults of Notophthalmus viridescens. Collectively the results suggest that, in adult urodeles, the mandible and the dental lamina can be replaced in an identical manner more than one time. Although the major histological events are the same in jaw regeneration and re-regeneration, regrowth is more rapid in re-regeneration. It appears that recently differentiated tissues of the regenerate have a higher capacity for regeneration than normal tissues amputated for the first time. Re-regeneration of the jaw occurs by growth of the original regenerate cartilage which has undergone reorganization. In re-regeneration, the skeletal elements exhibit no polarity and regrowth occurs in both directions, while the dental lamina possesses an anterior-posterior polarity and can regrow in an anterior direction only. Information concerning the mechanisms involved in the regenerative events remain to be determined.

  7. Annual reversible plasticity of feeding structures: cyclical changes of jaw allometry in a sea urchin

    PubMed Central

    Ebert, Thomas A.; Hernández, José Carlos; Clemente, Sabrina

    2014-01-01

    A wide variety of organisms show morphologically plastic responses to environmental stressors but in general these changes are not reversible. Though less common, reversible morphological structures are shown by a range of species in response to changes in predators, competitors or food. Theoretical analysis indicates that reversible plasticity increases fitness if organisms are long-lived relative to the frequency of changes in the stressor and morphological changes are rapid. Many sea urchin species show differences in the sizes of jaws (demi-pyramids) of the feeding apparatus, Aristotle's lantern, relative to overall body size, and these differences have been correlated with available food. The question addressed here is whether reversible changes of relative jaw size occur in the field as available food changes with season. Monthly samples of the North American Pacific coast sea urchin Strongylocentrotus purpuratus were collected from Gregory Point on the Oregon (USA) coast and showed an annual cycle of relative jaw size together with a linear trend from 2007 to 2009. Strongylocentrotus purpuratus is a long-lived species and under field conditions individuals experience multiple episodes of changes in food resources both seasonally and from year to year. Their rapid and reversible jaw plasticity fits well with theoretical expectations. PMID:24500161

  8. Beam feasibility study of a collimator with in-jaw beam position monitors

    NASA Astrophysics Data System (ADS)

    Wollmann, Daniel; Nosych, Andriy A.; Valentino, Gianluca; Aberle, Oliver; Aßmann, Ralph W.; Bertarelli, Alessandro; Boccard, Christian; Bruce, Roderik; Burkart, Florian; Calvo, Eva; Cauchi, Marija; Dallocchio, Alessandro; Deboy, Daniel; Gasior, Marek; Jones, Rhodri; Kain, Verena; Lari, Luisella; Redaelli, Stefano; Rossi, Adriana

    2014-12-01

    At present, the beam-based alignment of the LHC collimators is performed by touching the beam halo with both jaws of each collimator. This method requires dedicated fills at low intensities that are done infrequently and makes this procedure time consuming. This limits the operational flexibility, in particular in the case of changes of optics and orbit configuration in the experimental regions. The performance of the LHC collimation system relies on the machine reproducibility and regular loss maps to validate the settings of the collimator jaws. To overcome these limitations and to allow a continuous monitoring of the beam position at the collimators, a design with jaw-integrated Beam Position Monitors (BPMs) was proposed and successfully tested with a prototype (mock-up) collimator in the CERN SPS. Extensive beam experiments allowed to determine the achievable accuracy of the jaw alignment for single and multi-turn operation. In this paper, the results of these experiments are discussed. The non-linear response of the BPMs is compared to the predictions from electromagnetic simulations. Finally, the measured alignment accuracy is compared to the one achieved with the present collimators in the LHC.

  9. Jaw mechanism and dental function in the late cretaceous basal eusuchian Iharkutosuchus.

    PubMed

    Osi, Attila; Weishampel, David B

    2009-08-01

    Iharkutosuchus makadii is a basal eusuchian crocodylian with multicusped teeth discovered from the Upper Cretaceous of Hungary. Skull and dentition morphology indicates an active food processing for this crocodylian. First among crocodylians, a combination of different analyses, including cranial adductor muscle reconstruction, tooth wear pattern, and enamel microstructure studies, is applied here to support this hypothesis. Data provide unambiguous evidence for significant dental occlusion that was a result of a unique, transverse mandibular movement. Reconstruction of the jaw adductors demonstrates strong muscles responsible for slow but active jaw closure as the motor of transverse jaw movement; nevertheless muscles producing rapid jaw closure were reduced. Macrowear orientations show a dominantly transverse movement of the mandibles completed by a slight anteroposterior component. Along with quadrate morphology, macrowear further indicates that this motion was accomplished by alternate rotation of the mandibles about the quadrate condyles. Dental morphology and wear patterns suggest two types of power stroke: a slicing-crushing stroke associated dominantly with anterior tooth-food-tooth contact (with a low degree of transverse mandibular movement) during in the early stage of mastication, and a grinding stroke with significant posterior tooth-tooth contact and a dynamic transverse movement occurring later. The patterns of microwear show a diverse diet for Iharkutosuchus including both soft and hard items. This is also supported by the microstructure of the thick, wrinkled enamel built up mostly by poorly developed columnar units. Based on wear patterns, ontogenetic variation in feeding habits of Iharkutosuchus is also recognized.

  10. Dynamic visual cues induce jaw opening and closing by tiger beetles during pursuit of prey

    PubMed Central

    Zurek, Daniel B.; Perkins, Madeleine Q.; Gilbert, Cole

    2014-01-01

    In dynamic locomotory contexts, visual cues often trigger adaptive behaviour by the viewer, yet studies investigating how animals determine impending collisions typically employ either stationary viewers or objects. Here, we describe a dynamic situation of visually guided prey pursuit in which both impending prey contact and escape elicit observable adaptive behaviours in the pursuer, a predatory beetle. We investigated which visual cues may independently control opening and closing of the beetle's jaws during chases of prey dummies. Jaw opening and closing typically occur when prey is within the 60° binocular field, but not at specific distances, angular sizes or time-to-collision. We show that a sign change in the expansion rate of the target image precedes jaw opening (16 ms) and closing (35 ms), signalling to the beetle that it is gaining on the target or that the target is getting away. We discuss the ‘sloppiness' of such variation in the lag of the behavioural response, especially jaw closing, as an adaptation to uncertainty about target position due to degradation of the target image by motion blur from the fast-running beetle. PMID:25376803

  11. Cystic lesions of the jaws - a clinicopathological study of 322 cases and review of the literature.

    PubMed

    Manor, Esther; Kachko, Leonid; Puterman, Max B; Szabo, George; Bodner, Lipa

    2012-01-01

    Three hundred and twenty-two patients (192 male and 130 female) with cystic lesions of the jaw were successfully diagnosed and treated. One hundred and fifty-five (48%) were radicular cysts, 80 (25%) were dentigerous cysts, 23 (7%) were odontogenic keratocyst (=keratocystic odontogenic tumor), 19 (6%) were eruption cysts, 16 (5%) were traumatic bone cysts, and 29 (9%) were non-odontogenic cysts. There were 95 in the pediatric age group (1 month to 16 years) and 227 in the adult age group (17 years and older). Male to female ratio was 1 in the pediatric age group and 1.7 in the adult age group. The treatment modalities were: marsupialization, enucleation, enucleation with bone grafting, or resection. The distribution and characteristics of jaw cysts in children are different from those in adults. In children there is a relatively high rate of developmental cysts, whereas in adults the inflammatory cysts are more common. Following enucleation of a cystic jaw lesion, the entire surgical specimen and not only a biopsy specimen, should be examined histopathologically to prevent any possibility of an intramural squamous cell carcinoma that may be overlooked. The differences in prevalence of each type of jaw cyst during a lifetime may point toward a multifactorial polygenic pattern rather than a monogenic pattern.

  12. Cystic Lesions of the Jaws - A Clinicopathological Study of 322 Cases and Review of the Literature

    PubMed Central

    Manor, Esther; Kachko, Leonid; Puterman, Max B.; Szabo, George; Bodner, Lipa

    2012-01-01

    Three hundred and twenty-two patients (192 male and 130 female) with cystic lesions of the jaw were successfully diagnosed and treated. One hundred and fifty-five (48%) were radicular cysts, 80 (25%) were dentigerous cysts, 23 (7%) were odontogenic keratocyst (=keratocystic odontogenic tumor), 19 (6%) were eruption cysts, 16 (5%) were traumatic bone cysts, and 29 (9%) were non-odontogenic cysts. There were 95 in the pediatric age group (1 month to 16 years) and 227 in the adult age group (17 years and older). Male to female ratio was 1 in the pediatric age group and 1.7 in the adult age group. The treatment modalities were: marsupialization, enucleation, enucleation with bone grafting, or resection. The distribution and characteristics of jaw cysts in children are different from those in adults. In children there is a relatively high rate of developmental cysts, whereas in adults the inflammatory cysts are more common. Following enucleation of a cystic jaw lesion, the entire surgical specimen and not only a biopsy specimen, should be examined histopathologically to prevent any possibility of an intramural squamous cell carcinoma that may be overlooked. The differences in prevalence of each type of jaw cyst during a lifetime may point toward a multifactorial polygenic pattern rather than a monogenic pattern. PMID:22211085

  13. Alendronate-associated osteonecrosis of the jaws: a review of the main topics.

    PubMed

    Paiva-Fonseca, F; Santos-Silva, A-R; Della-Coletta, R; Vargas, P-A; Lopes, M-A

    2014-03-01

    Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate, particularly alendronate, has also been reported by a number of authors. Considering that alendronate is one of the most used drug worldwide, specially for treatment of osteoporosis, a better understanding of osteonecrosis of the jaws related to its use and how to manage these patients is extremely important. Therefore, in the current manuscript the authors aim to review the most important topics related to this pathological presentation.

  14. Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA

    SciTech Connect

    Han, Eun Young; Kim, Dong-Wook; Zhang, Xin; Penagaricano, Jose; Liang, Xiaoying; Hardee, Matthew; Morrill, Steve; Ratanatharathorn, Vaneerat

    2015-10-01

    It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.

  15. [Support at home for a patient with cancer of the jaw].

    PubMed

    Brauer, Monique

    2015-09-01

    Home care presents specific difficulties. The support of Ms. C, suffering from a malignant tumour of the lower jaw illustrates a difficult care context due to a painful and poorly-healing wound, low self-esteem and communication difficulties. Maintaining the right distance and providing professional support are therefore essential in order to give high quality care to this patient.

  16. Bisphosphonate-related osteonecrosis of the jaws--a case report.

    PubMed

    Kamoh, Amandip K; Ogle, Orrett

    2012-05-01

    Bisphosphonates are commonly prescribed for the treatment of osteoporosis and bone cancers. These drugs come in both intravenous and oral forms. Because these drugs have become more prevalent, there have been increased reports of bisphosphonate-related osteonecrosis of the jaws (BRONJ). This case presentation focuses on a 50-year-old woman with a 10-year history of monthly Zometa (zoledronic acid) use for treatment of multiple myeloma, resulting in BRONJ with a very unfavorable outcome. Its purpose is to depict how the chronic use of intravenous (i.v.) bisphosphonates can lead to bisphosphonate-related osteonecrosis of the jaw (BRONJ), and to present treatment options, including conservative measures, the dentist may be able to employ in the early phases of the disease, along with the indications for jaw resection. Osteonecrosis of the jaws in association with bisphosphonate therapy is a very serious condition with which all dentists should be familiar. When the osteonecrosis begins, it can be very painful to the patient, difficult to treat, and can lead to very deleterious sequelae.

  17. [Use of bioactive glass ceramic material Biociyal-11 - experimental substantiation for jaw bone defects replacement].

    PubMed

    Bezzubik, S D; Grechukha, A M

    2009-01-01

    Pequliarities of morphologic osseous reparation of jaw bone defects in 15 non-bred dogs after implantation of different forms of glass crystal material Biocital-11 and blood clot on 7, 14, 21, 30 and 180th day after operation were shown. High biocompatibility of the material Biocital-11 with expressed osseous conductive function was disclosed.

  18. Bisphosphonates, vitamin D, parathyroid hormone, and osteonecrosis of the jaw. Could there be a missing link?

    PubMed Central

    Leizaola-Cardesa, Ignacio-Osoitz; Aguilar-Salvatierra, Antonio; Gonzalez-Jaranay, Maximino; Moreu, Gerardo; Sala-Romero, María-José

    2016-01-01

    It is estimated that over 190 million bisphosphonates have been prescribed worldwide. But this drug can produce adverse effects, of which osteonecrosis of the jaw and severe hypocalcemia are the most serious. It is evident that bisphosphonate administration affects multiple and diverse biochemical mediators related to bone metabolism. This review of literature investigates four basic parameters in patients treated with bisphosphonates - parathyroid hormone (PTH), bisphosphonates, vitamin D, calcium, and jaw osteonecrosis - which are fundamental for assessing bone metabolism and so the efficacy and correct use of the drug. The imbalances generated by vitamin D and calcium deficiencies, together with their multiple systemic repercussions, have been widely researched but the outcomes of these imbalances in relation to bisphosphonate administration are not well known, and some research has indicated that they may be associated with osteonecrosis of the jaw (ONJ). The present review set out to explain the functioning of bone metabolism, the importance of different chemical mediators, the imbalances produced by incorrect use of this drug, in order to forewarn against the possible relation of these parameters with ONJ, whose physiopathology remains unknown. Medical and dental clinics should keep detailed anamneses of the use of vitamin D and calcium supplements, as it is of vital importance to maintain their correct levels in blood, given that these are related to ONJ as well as other adverse effects; this procedure is also necessary in order to ensure the correct use of the drug. Key words:Bisphosphonate-related osteonecrosis of the jaw, vitamin D, parathyroid hor PMID:26827062

  19. Partial (focal) seizure

    MedlinePlus

    ... Jacksonian seizure; Seizure - partial (focal); Temporal lobe seizure; Epilepsy - partial seizures ... Abou-Khalil BW, Gallagher MJ, Macdonald RL. Epilepsies. In: Daroff ... Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 101. ...

  20. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  1. Localization of central rhythm generator involved in cortically induced rhythmical masticatory jaw-opening movement in the guinea pig.

    PubMed

    Nozaki, S; Iriki, A; Nakamura, Y

    1986-04-01

    The location of the central rhythm generator involved in the cortically induced rhythmical masticatory jaw-opening movement was studied in the ketamine-anesthetized guinea pig. These studies show that a population of neurons is activated by a nonrhythmical input from the cortical masticatory area (CMA) and produces a rhythmical output to the trigeminal motoneurons innervating the jaw-opening muscles. Repetitive stimulation (30 Hz) of the pyramidal tract (PT) rostral to the middle level of the medulla oblongata, in the animal with a precollicular transection as well as with an intact neuraxis, induced a rhythmical reciprocal EMG activity in the anterior digastric and masseter muscles. The rhythmical activity could be monitored by a rhythmical burst in the efferent discharge in the mylohyoid nerve innervating the anterior digastric muscle. Essentially the same pattern was observed when stimulating the PT as that induced by repetitive stimulation of the CMA. The rhythmical efferent burst in the mylohyoid nerve could still be induced after paralyzing the animal. Repetitive PT stimulation in the isolated brain stem after precollicular and bulbospinal transections induced a rhythmical pattern in the anterior digastric EMG and an efferent activity in the mylohyoid nerve. The rhythmical mylohyoid nerve burst could be induced after paralyzing the animal. After section of the medial part of the brain stem at the pontobulbar junction, including the PT, repetitive PT stimulation at the pontine level did not induce any masticatory activity either in the digastric EMG or in the efferent discharge in the mylohyoid nerve, while stimulation at the rostral bulbar level still induced a rhythmicity that was essentially the same pattern as before the section. By testing the effects of total and partial transections of the brain stem in coronal and sagittal planes at various locations, we found that the medial bulbar reticular formation, the lateral pons including the trigeminal motor

  2. Assessment of potential jaw-tracking advantage using control point sequences of VMAT planning.

    PubMed

    Kim, Jung-in; Park, Jong Min; Park, So-Yeon; Choi, Chang Heon; Wu, Hong-Gyun; Ye, Sung-Joon

    2014-03-06

    This study aims to evaluate the potential jaw-tracking advantage using control point sequences of volume volumetric modulated arc therapy (VMAT) planning. VMAT plans for patients with prostate and head and neck (H&N) cancers were converted into new static arc (SA) plans. The SA plan consisted of a series of static fields at each control point of the VMAT plan. All other machine parameters of the SA plan were perfectly identical to those of the original VMAT plan. The jaw-tracking static arc (JTSA) plans were generated with fields that closed the jaws of each SA field into the multileaf collimators (MLCs) aperture. The dosimetric advantages of JTSA over SA were evaluated in terms of a dose-volume histogram (DVH) of organ at risk (OAR) after renormalizing both plans to make the same target coverage. Both plans were delivered to the MatriXX-based COMPASS system for 3D volume dose verification. The average jaw size reduction of the JTSA along the X direction was 3.1 ± 0.9 cm for prostate patients and 6.9 ± 1.9 cm for H&N patients. For prostate patients, the organs far from the target showed larger sparing (3.7%-8.1% on average) in JTSA than the organs adjacent to the target (1.1%-1.5%). For the H&N plans, the mean dose reductions for all organs ranged from 4.3% to 11.9%. The dose reductions were more significant in the dose regions of D80, D90, and D95 than the dose regions of D5, D10, and D20 for all patients. Likewise, the deliverability and reproducibility of jaw-tracking plan were validated. The measured dosimetric advantage of JTSA over SA coincided with the calculated one above.

  3. Bone metabolism and clinical study of 44 patients with bisphosphonate-related osteonecrosis of the jaws

    PubMed Central

    Bocanegra-Pérez, María S.; Sosa-Henríquez, Manuel; Rodríguez-Bocanegra, Eduardo; Limiñana-Cañal, José M.; López-Márquez, Ariadna; Pérez-Plasencia, Daniel; Ramos-Macías, Angel

    2012-01-01

    Osteonecrosis of the jaws is a clinical entity described and linked to treatment with bisphosphonates in 2003. Its real incidence is unknown and it could increase due to the large number of patients treated with these drugs, and its cumulative effect on the bone. State of the art knowledge regarding its etiopathogeny, clinical course and suitable treatments is limited. Objectives: To study the clinical characteristics of 44 patients with bisphosphonate-related osteonecrosis of the jaws and the state of their bone mineral metabolism: bone remodeling state, prevalence of fractures, bone mineral density study, and assessment of the different treatment strategies. Design of the Study: Observational. Information was gathered prospectively through interviews, clinical examinations, additional tests and review of medical records. Results: We studied 16 men and 28 women with a mean age of 64.7 years. Breast cancer was the most frequent underlying disease. Zoledronate was used in 82% of the cases and in the non-oncology group of patients; alendronate was the most frequently used bisphosphonate. The mean duration of the zoledronate and alendronate treatments was 25 months and 88 months respectively. The lower jaw was the most frequent location, and previous exodontias—among the triggering factors known—were the most closely linked to its onset. We found considerable osteoblastic activity in patients suffering from neoplasia, with artifacts present in their bone densitometry and a high percentage of vertebral fractures. Conclusions: According to our results, osteonecrosis of the jaws affects elderly patients. We found a direct relationship between the duration of exposure and the accumulated dose. Other relevant factors are: Poor oral and dental health, corticoids, diabetes and teeth extractions. In essence, it is a clinical diagnosis. Prevention is the best strategy to handle this clinical entity. Key words:Alendronate, bisphosphonate, jaw, maxilla, osteonecrosis

  4. Fatigue and pain in human jaw muscles during a sustained, low-intensity clenching task.

    PubMed

    Svensson, P; Burgaard, A; Schlosser, S

    2001-08-01

    Fatigue, pain and changes in the electromyographic (EMG) activity of the jaw-closing muscles are well documented during short, high-intensity tooth-clenching tasks but less so during sustained, low-intensity tasks. In this study, 11 healthy men clenched on a bite-force meter for 60 min at 10% of the maximal voluntary contraction (MVC) and scored the intensity of fatigue and pain on separate 10 cm visual analogue scales (VAS). Surface EMG activity from the masseter and anterior temporalis muscles was recorded in 10 s epochs every 5 min throughout the task. Pressure-pain thresholds (PPTs) in the jaw-closing muscles, unassisted maximum jaw opening and MVC were determined before and after the task. All participants reported an increasing sensation of fatigue in the jaw-closing muscles during the task (mean+/-SD: peak VAS=7.5+/-2.0 cm) but all were able to maintain the required force. Most (7/11) also reported a painful sensation (peak VAS=2.7+/-2.8 cm). The jaw-opening capacity (59.5+/-7.4 vs. 58.3+/-6.5 mm, P=0.031) and the MVC (777+/-73 vs. 652+/-115 N,P=0.002) were slightly, but significantly, decreased immediately after the task whereas the PPTs remained unchanged (ANOVA: P=0.612). The mean frequency of the EMG activity decreased in all muscles during the task (95.7 vs. 46.6 Hz;P<0.001), and the root mean squares increased (53.2 vs. 154 microV, P<0.001). The changes in EMG activity were more strongly correlated with the sensation of fatigue than pain. These findings demonstrate that a sustained, low-intensity clenching task can induce subjective and electrophysiological indications of fatigue.

  5. Recurrent Maxillary Odontogenic Myxoma Following Partial Maxillary Resection and Consecutive Osseous Reconstruction Including Tooth Transplantation.

    PubMed

    Friedrich, Reinhard E; Scheuer, Hanna A; Höltje, Wolf

    2016-06-01

    Odontogenic myxoma (OM) is a rare tumour arising in the jaws. The tumour is purported to be odontogenic in origin due to the frequent localisation of the tumour inside the jaws in close relation to teeth. The aim of this report was to detail the course of a patient who developed OM of the maxilla, underwent adequate ablative surgery and reconstruction, including tooth transplantation to the original tumour site, and subsequently developed a local recurrence in close proximity to the teeth transplanted to the reconstructed maxilla 6 years after the first diagnosis. Once again, a partial maxillary resection was performed, with no reconstruction. The patient has been free from tumour recurrence for over 20 years. We discuss the current hypothesis on OM pathogenesis and the possible impact of actively dividing cells on tumour re-growth. PMID:27272841

  6. An interactive three dimensional approach to anatomical description—the jaw musculature of the Australian laughing kookaburra (Dacelo novaeguineae)

    PubMed Central

    Barnes, David G.; Kaluza, Owen L.; McHenry, Colin R.

    2014-01-01

    The investigation of form-function relationships requires a detailed understanding of anatomical systems. Here we document the 3-dimensional morphology of the cranial musculoskeletal anatomy in the Australian Laughing Kookaburra Dacelo novaeguineae, with a focus upon the geometry and attachments of the jaw muscles in this species. The head of a deceased specimen was CT scanned, and an accurate 3D representation of the skull and jaw muscles was generated through manual segmentation of the CT scan images, and augmented by dissection of the specimen. We identified 14 major jaw muscles: 6 in the temporal group (M. adductor mandibulae and M. pseudotemporalis), 7 in the pterygoid group (M. pterygoideus dorsalis and M. pterygoideus ventralis), and the single jaw abductor M. depressor mandibulae. Previous descriptions of avian jaw musculature are hindered by limited visual representation and inconsistency in the nomenclature. To address these issues, we: (1) present the 3D model produced from the segmentation process as a digital, fully interactive model in the form of an embedded 3D image, which can be viewed from any angle, and within which major components can be set as opaque, transparent, or hidden, allowing the anatomy to be visualised as required to provide a detailed understanding of the jaw anatomy; (2) provide a summary of the nomenclature used throughout the avian jaw muscle literature. The approach presented here provides considerable advantages for the documentation and communication of detailed anatomical structures in a wide range of taxa. PMID:24860694

  7. An interactive three dimensional approach to anatomical description-the jaw musculature of the Australian laughing kookaburra (Dacelo novaeguineae).

    PubMed

    Quayle, Michelle R; Barnes, David G; Kaluza, Owen L; McHenry, Colin R

    2014-01-01

    The investigation of form-function relationships requires a detailed understanding of anatomical systems. Here we document the 3-dimensional morphology of the cranial musculoskeletal anatomy in the Australian Laughing Kookaburra Dacelo novaeguineae, with a focus upon the geometry and attachments of the jaw muscles in this species. The head of a deceased specimen was CT scanned, and an accurate 3D representation of the skull and jaw muscles was generated through manual segmentation of the CT scan images, and augmented by dissection of the specimen. We identified 14 major jaw muscles: 6 in the temporal group (M. adductor mandibulae and M. pseudotemporalis), 7 in the pterygoid group (M. pterygoideus dorsalis and M. pterygoideus ventralis), and the single jaw abductor M. depressor mandibulae. Previous descriptions of avian jaw musculature are hindered by limited visual representation and inconsistency in the nomenclature. To address these issues, we: (1) present the 3D model produced from the segmentation process as a digital, fully interactive model in the form of an embedded 3D image, which can be viewed from any angle, and within which major components can be set as opaque, transparent, or hidden, allowing the anatomy to be visualised as required to provide a detailed understanding of the jaw anatomy; (2) provide a summary of the nomenclature used throughout the avian jaw muscle literature. The approach presented here provides considerable advantages for the documentation and communication of detailed anatomical structures in a wide range of taxa. PMID:24860694

  8. Water temperature induces jaw deformity and bone morphogenetic proteins (BMPs) gene expression in golden pompano Trachinotus ovatus larvae.

    PubMed

    Ma, Zhenhua; Zhang, Nan; Qin, Jian G; Fu, Mingjun; Jiang, Shigui

    2016-01-01

    Golden pompano Trachinotus ovatus larvae were kept at 26, 29 and 33 °C for 15 days from 3-day post hatching (DPH) to 18 DPH to test temperature-dependent growth and jaw malformation. The growth, survival, jaw deformity and the gene expressions of bone morphogenetic proteins (BMPs) were used as criteria to examine the fish response to temperature manipulation. The growth rate of fish at 29 or 33 °C was significantly faster than fish at 26 °C, while fish survival at 29 °C was significantly higher than fish at 33 °C. Jaw deformity was significantly affected by water temperature. The highest jaw deformity occurred on fish at 33 °C, and the lowest jaw deformity was at 26 °C. The expressions of all BMP genes except BMP10 were significantly affected by water temperature. The highest gene expression of BMP2 was on fish at 29 °C, and the lowest expression was at 33 °C. For the BMP4 gene, the highest and lowest expressions were found on fish at 33 and 26 °C, respectively. The present study indicates that jaw deformity of golden pompano larvae increases with increasing temperature, and the gene expression of BMP4 proteins coincides with high jaw deformity and water temperature elevation.

  9. Water temperature induces jaw deformity and bone morphogenetic proteins (BMPs) gene expression in golden pompano Trachinotus ovatus larvae.

    PubMed

    Ma, Zhenhua; Zhang, Nan; Qin, Jian G; Fu, Mingjun; Jiang, Shigui

    2016-01-01

    Golden pompano Trachinotus ovatus larvae were kept at 26, 29 and 33 °C for 15 days from 3-day post hatching (DPH) to 18 DPH to test temperature-dependent growth and jaw malformation. The growth, survival, jaw deformity and the gene expressions of bone morphogenetic proteins (BMPs) were used as criteria to examine the fish response to temperature manipulation. The growth rate of fish at 29 or 33 °C was significantly faster than fish at 26 °C, while fish survival at 29 °C was significantly higher than fish at 33 °C. Jaw deformity was significantly affected by water temperature. The highest jaw deformity occurred on fish at 33 °C, and the lowest jaw deformity was at 26 °C. The expressions of all BMP genes except BMP10 were significantly affected by water temperature. The highest gene expression of BMP2 was on fish at 29 °C, and the lowest expression was at 33 °C. For the BMP4 gene, the highest and lowest expressions were found on fish at 33 and 26 °C, respectively. The present study indicates that jaw deformity of golden pompano larvae increases with increasing temperature, and the gene expression of BMP4 proteins coincides with high jaw deformity and water temperature elevation. PMID:27652050

  10. An interactive three dimensional approach to anatomical description-the jaw musculature of the Australian laughing kookaburra (Dacelo novaeguineae).

    PubMed

    Quayle, Michelle R; Barnes, David G; Kaluza, Owen L; McHenry, Colin R

    2014-01-01

    The investigation of form-function relationships requires a detailed understanding of anatomical systems. Here we document the 3-dimensional morphology of the cranial musculoskeletal anatomy in the Australian Laughing Kookaburra Dacelo novaeguineae, with a focus upon the geometry and attachments of the jaw muscles in this species. The head of a deceased specimen was CT scanned, and an accurate 3D representation of the skull and jaw muscles was generated through manual segmentation of the CT scan images, and augmented by dissection of the specimen. We identified 14 major jaw muscles: 6 in the temporal group (M. adductor mandibulae and M. pseudotemporalis), 7 in the pterygoid group (M. pterygoideus dorsalis and M. pterygoideus ventralis), and the single jaw abductor M. depressor mandibulae. Previous descriptions of avian jaw musculature are hindered by limited visual representation and inconsistency in the nomenclature. To address these issues, we: (1) present the 3D model produced from the segmentation process as a digital, fully interactive model in the form of an embedded 3D image, which can be viewed from any angle, and within which major components can be set as opaque, transparent, or hidden, allowing the anatomy to be visualised as required to provide a detailed understanding of the jaw anatomy; (2) provide a summary of the nomenclature used throughout the avian jaw muscle literature. The approach presented here provides considerable advantages for the documentation and communication of detailed anatomical structures in a wide range of taxa.

  11. Intraosseous carcinoma of the jaws--a clinicopathologic review. Part I: Metastatic and salivary-type carcinomas.

    PubMed

    Woolgar, Julia A; Triantafyllou, Asterios; Ferlito, Alfio; Devaney, Kenneth O; Lewis, James S; Rinaldo, Alessandra; Slootweg, Pieter J; Barnes, Leon

    2013-06-01

    This is the first part of a 3-part comprehensive review of intraosseous carcinoma of the jaws. We have outlined 4 groups of intraosseous carcinoma of the jaws (metastatic, salivary-type, odontogenic, and primary intraosseous carcinoma), emphasizing the need for accurate diagnosis and the problems associated with changing classification systems, standardization of diagnostic criteria and nomenclature, and the accuracy of existing literature. In this first part, the features of metastatic and the very rare salivary-type carcinomas of the jaws are examined with particular emphasis on histologic and immunohistochemical characteristics, diagnostic difficulties, and uncertainties.

  12. Patterns of tongue and jaw movement in a cinefluorographic study of feeding in the macaque.

    PubMed

    Hiiemae, K M; Hayenga, S M; Reese, A

    1995-03-01

    Tongue movements in three female Macaca fascicularis, with radio-opaque markers in the tongue, teeth and hyoid, feeding on apple, banana and monkey chow, were recorded using lateral projection cineradiography (+/- 100 f.p.s.) with synchronized frontal view cinephotography (50 f.p.s.). Marker positions were digitized and the resultant Cartesian coordinates manipulated: (a) to establish the gape time profile; (b) anteroposterior and dorsoventral movements of tongue and hyoid markers relative to an upper occlusal/palatal reference plane; and (c) expansion and contraction of tongue segments in selected sections of complete sequences. The relative timing of tongue and jaw movement events was established using interval analysis. In simple transport cycles (semisolid food), all parts of the tongue moved in synchrony, travelling forwards and expanding during early opening, and backwards and contracting during late opening and closing. In contrast, in simple chewing cycles with a power stroke (SC phase): (a) the tongue markers reached their most backward position before or at the beginning of the SC phase, travelling forwards until the teeth approached intercuspation, then paused until after the teeth had reached centric occlusion; (b) the markers moved asynchronously, so that the relation between each marker and jaw movement changed; (c) expansion and contraction was largely confined to the middle tongue segment. In complex chewing cycles, jaw movement in opening was linked to the behaviour of the anterior tongue segment: reversal from forward to backward movement of the anterior tongue marker occurred within 30 ms of the rate change at the SO (slow open)-FO (fast open) transition: the greater the amplitude of forward movement, the longer the SO phase/Hyoid (tongue base) movement occurred throughout masticatory sequences. A backward drift of the hyoid and posterior part of the tongue occurred in cycles preceding swallows. Linkages between tongue and jaw movements in

  13. Helical and Static-port Tomotherapy Using the Newly-developed Dynamic Jaws Technology for Lung Cancer.

    PubMed

    Manabe, Yoshihiko; Shibamoto, Yuta; Sugie, Chikao; Hayashi, Akihiro; Murai, Taro; Yanagi, Takeshi

    2015-10-01

    With the newly developed dynamic jaws technology, radiation dose for the cranio-caudal edges of a target can be lowered in the treatment with tomotherapy. We compared dynamic-jaw- and fixed-jaw-mode plans for lung cancer. In 35 patients, four plans using the 2.5-cm dynamic-, 2.5-cm fixed-, 5.0-cm dynamic-, and 5.0-cm fixed-jaw modes were generated. For 10 patients with upper lobe stage I lung cancer, the helical tomotherapy mode was used. Fifty-six Gy in 8 fractions was prescribed as a minimum coverage dose for 95% of the target (D95%). For 25 patients with locally advanced lung cancer, plans using four static ports (TomoDirect® mode) were made. Sixty Gy in 30 daily fractions for the primary tumor and swollen lymph nodes and 51 Gy in 30 fractions for prophylactic lymph node areas were prescribed as median doses. The mean conformity index of the planning target volume were similar among the four plans. The mean V5 Gy of the lung for 2.5-cm dynamic-, 2.5-cm fixed-, 5.0-cm dynamic-, and 5.0-cm fixed-jaw mode plans were 18.5%, 21.8%, 20.1%, and 29.4%, respectively (p < 0.0001), for patients with stage I lung cancer, and 37.3%, 38.7%, 40.4%, and 44.0%, respectively (p < 0.0001), for patients with locally advanced lung cancer. The mean V5 Gy of the whole body was 1,826, 2,143, 1,983, and 2,939 ml, respectively (p < 0.0001), for patients with stage I lung cancer and 4,849, 5,197, 5,220, and 6,154 ml, respectively (p < 0.0001), for patients with locally advanced lung cancer. Treatment time was reduced by 21-39% in 5.0-cm dynamic-jaw plans compared to 2.5-cm plans. Regarding dose distribution, 2.5-cm dynamic-jaw plans were the best, and 5.0-cm dynamic-jaw plans were comparable to 2.5-cm fixed-jaw plans with shorter treatment times. The dynamic-jaw mode should be used instead of the conventional fixed-jaw mode in tomotherapy for lung cancer.

  14. Actinomyces israelii in osteoradionecrosis of the jaws. Histopathologic and immunocytochemical study of five cases

    SciTech Connect

    Happonen, R.P.; Viander, M.; Pelliniemi, L.; Aitasalo, K.

    1983-06-01

    Five surgically treated patients with osteoradionecrosis of the jaws are presented. The clinical history of the disease varied from 3 to 17 years. In three cases the progression of the disease was enhanced by surgical procedures performed in the irradiated area causing exfoliation of the premaxillary area in one case and spontaneous mandibular fracture in two cases. Actinomyces israelii was demonstrated in tissue sections of all five cases by using FITC-labeled specific antiserum and additionally with peroxidase-antiperoxidase method in one case. Candida was found in histologic sections of three cases. Radiation damage in the oral soft tissues and jawbones makes the atmosphere favorable for anaerobic microorganisms. The present results indicate that the role of A. israelii in the pathogenesis of osteoradionecrosis of the jaws has not been fully appreciated.

  15. Jaw tumor in primary hyperparathyroidism is not always a brown tumor

    PubMed Central

    Ennazk, Laila; El Mghari, Ghizlane; El Ansari, Nawal

    2016-01-01

    Summary Primary hyperparthyrodism (PHPT) is a common endocrine disease. It results from an inappropriate parathyroid hormone (PTH) secretion relative to serum ionized calcium level. Clinical manifestation of severe PHPT include bone disease called osteitis fibrosa cystica which reflects an increase osteoclastic resorption and osteoblastic activity. This high bone turnover is responsible of the occurrence of osteoclastomas, also named “brown tumors” (1). Rarely, PHPT may occur in inherited forms with association to fibrous jaw tumor that are unrelated to hyperparathyroidism. In this uncommon disease: hyperparathyroidism-jaw tumor (HPT-JT) syndrome, parathyroid tumor is frequently malignant and usually associated with nonendocrine malignancies (2). We report a case of a HPT-JT syndrome to focus on the differential diagnosis with brown tumors. PMID:27252751

  16. Testosterone, anastrozole, factor V Leiden heterozygosity and osteonecrosis of the jaws.

    PubMed

    Pandit, Ramesh S; Glueck, Charles J

    2014-04-01

    Our specific aim is to describe the development of thrombotic osteonecrosis of the jaws after testosterone-anastrozole therapy in a 55-year-old white man subsequently found to have previously undiagnosed factor V Leiden heterozygosity. Before the diagnosis of V Leiden heterozygosity, he was given testosterone gel, 50 mg/day, and on testosterone, serum testosterone (963 ng/dl) and estradiol were high (50 pg/ml). Anastrozole was started, and testosterone was continued. Six months later, osteonecrosis of the jaws was diagnosed. Exogenous testosterone is aromatized to estradiol and estradiol-induced thrombophilia, when superimposed on underlying familial thrombophilia, as in this case, may lead to thrombosis and osteonecrosis. We recommend that before giving testosterone, at a minimum, screening for the factor V Leiden and G20210A mutations, and factor VIII and XI activity be carried out, to avoid unanticipated thrombosis.

  17. Biphosphonates-related osteonecrosis of the jaw: Clinical and physiopathological considerations

    PubMed Central

    Borgioli, Alberto; Viviani, Christian; Duvina, Marco; Brancato, Leila; Spinelli, Giuseppe; Brandi, Maria Luisa; Tonelli, Paolo

    2009-01-01

    Since osteonecrosis of the jaw was related to biphosphonate administration by Marx, studies showing clinical symptoms, drug and surgical therapies overwhelmed the literature. Furthermore, the literature demonstrated the correlation between chronic biphosphonate adsumption and osteonecrosis of the jaw onset. Nitrogen-containing biphosphonates are widely used for the management of metastatic cancer, for prevention and treatment of osteoporosis, for the treatment of Paget's disease, and for the management of acute hypercalcemia. According to our experience, the treatment of BRON-J's lesions is difficult and prolonged. For this reason, in order to avoid these complications it is mandatory to perform a risk staging in patients who must undergo biphosphonate administration. When pharmacologic treatments with antibiotics and local antiseptics are not able to control the development of BRON-J's complications, the clinicians should perform radical surgical treatments such as the resection of the bone involved. PMID:19436626

  18. Protein-signaled guided total jaw regeneration in infantile total mandibular resection.

    PubMed

    Balaji, S M

    2014-01-01

    Maxillofacial reconstruction on a young child with huge aggressively growing lesion is a tough situation owing to several limiting factors. Besides the other factors, impact of the growing lesion on the psychology of the child also needs to be considered. This manuscript reports a case of an 18-month-old boy with juvenile cemento-ossifying fibroma in whom removal of a large portion of the jaws was required. The regeneration of the jaw bones with the help of protein signal guided reconstruction using bone morphogenetic protein-2 is described. Long-term follow-up of the patient with dental implants placed on the neo-osteogenic bone is reported. PMID:25593874

  19. The role of microbial biofilms in osteonecrosis of the jaw associated with bisphosphonate therapy.

    PubMed

    Kumar, Satish K S; Gorur, Amita; Schaudinn, Christoph; Shuler, Charles F; Costerton, J William; Sedghizadeh, Parish P

    2010-03-01

    Microbial biofilms have been observed and described in bone specimens of patients with bisphosphonate (BP)-associated osteonecrosis of the jaw (BONJ) and investigators are more recently suggesting that this condition essentially represents an osteomyelitis of the jaw clinically, with greater susceptibility in some patients on BP therapy. This article explains the role of microbial biofilms in BONJ and also discusses associated factors in the disease pathogenesis, which include BP effects on bone remodeling, anti-angiogenesis, matrix necrosis, microcracks, soft tissue toxicity, and inflammation and wound healing. Recent findings suggest a key role for microbial biofilms in the pathogenesis of BONJ; this has important therapeutic implications because biofilm organisms represent a clinical target for prevention and treatment efforts aimed at reducing the significant morbidity and costs associated with this condition.

  20. Changes in shape of posterior parts of upper jaws after extraction of teeth and prosthetic treatment.

    PubMed

    Berg, H; Carlsson, G E; Helkimo, M

    1975-09-01

    Changes in the sagittal and transverse profiles of the anterior and posterior parts of the alveolar process after extraction of all teeth and insertion of immediate dentures were studied during a five-year period using casts of 14 patients. The casts were oriented in a uniform way with the help of reference points in the hard palate. The desired profiles could then be reproduced with a special tracing apparatus. Four profiles made during the five-year period were compared for each patient. Changes in shape of the upper jaws in the median sagittal plane agreed well with the results obtained in earlier investigations and showed a reduction of the anterior part of the alveolar process for each patient. In the posterior part of the upper jaw, on the other hand, an increase in size was seen in the transverse section of the alveolar process in most patients examined.

  1. Mouthing off about fish capture: Jaw movement in pinnipeds reveals the real secrets of ingestion

    NASA Astrophysics Data System (ADS)

    Liebsch, N.; Wilson, R. P.; Bornemann, H.; Adelung, D.; Plötz, J.

    2007-02-01

    Determination of when and where animals feed and how much they consume is fundamental to understand their ecology and role in ecosystems. However, the lack of reliable data on feeding habits of wild animals, and particularly in marine endotherms, attests to the difficulty in doing this. A promising recent development proposes using a Hall sensor-magnet system, the inter-mandibular angle sensor (IMASEN) attached to animals' jaws to elucidate feeding events. We conducted trials on captive pinnipeds by feeding IMASEN-equipped animals with prey to examine the utility of this system. Most feeding events were clearly distinguishable from other jaw movements; only small prey items might not be resolved adequately. Based on the results of this study we examined feeding events from free-ranging pinnipeds fitted with IMASENs and dead-reckoners and present data on prey capture and ingestion in relation to the three-dimensional movement patterns of the seals.

  2. [The rare case of osteonecrosis of the jaws in a patient treated with bisphosphonates for osteoporosis].

    PubMed

    Lewandowski, Bogumił; Brodowski, Robert; Kość, Tomasz; Migut, Małgorzata; Wojnar, Joanna

    2016-01-01

    Bisphosphonates are used primarily in patients with bone metastases and osteoporosis One of the local complications, less well-known to doctors, associated with the use of bisphosphonates is osteonecrosis of the jaw (Biophosphatate Related osteonecrosis of the jaw--BRONJ). It affects approximately 1-10% of patients and may cause diagnostic difficulties because of its similarity to a primary focus in the bone. This issue can be encountered by the doctors of various specialties who use bisphosphonates. The purpose of this study is to present a case of the patient with BRONJ symptoms following the administration of bisphosphonate therapy, which can occur in the doctors practice. Concluding, maintaining good health of the oral cavity before starting the therapy reduces the incidence of BROKJ. Before starting bisphosphonate therapy, all patients should be referred to dental consultation to assess the potential foci of infection in the mouth.

  3. A case of early detection of bisphosphonate-related osteonecrosis of the jaw.

    PubMed

    Mori, Miyu; Koide, Tetsuro; Matsui, Yuriyo; Matsuda, Toru

    2015-01-01

    Osteonecrosis of the jaws is an adverse reaction associated with the use of bisphosphonates. Although the diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is based on symptomatology, it is often detected late because the patients become symptomatic only after osteonecrosis is well established. We describe a case of early oral BRONJ detected by magnetic resonance imaging (MRI) accidentally. Head MRI revealed low signal of T1-weight images in left mandibula. Patient had been treated with minodronate for osteoporosis during 18 months. Based on the MRI findings and medication history, early stage BRONJ could be considered. Therefore minodronate was switched to teriparatide. Thereafter mandible pares-thesias, odontalgia and exposed bone were not observed. This case suggests that MRI is useful for the early detection of BRONJ.

  4. Initial radiation of jaws demonstrated stability despite faunal and environmental change.

    PubMed

    Anderson, Philip S L; Friedman, Matt; Brazeau, Martin D; Rayfield, Emily J

    2011-07-06

    More than 99 per cent of the roughly 58,000 living vertebrate species have jaws. This major clade, whose members are collectively known as gnathostomes ('jawed mouths'), made its earliest definitive appearance in the Silurian period, 444-416 million years (Myr) ago, with both the origin of the modern (crown-group) radiation and the presumptive invasion of land occurring by the end of the Devonian period (359 Myr ago). These events coincided with a major faunal shift that remains apparent today: the transition from Silurian ecosystems dominated by jawless fishes (agnathans) to younger assemblages composed almost exclusively of gnathostomes. This pattern has inspired several qualitative descriptions of the trophic radiation and ecological ascendance of the earliest jawed vertebrates. Here we present a quantitative analysis of functional variation in early gnathostome mandibular elements, placing constraints on our understanding of evolutionary patterns during this critical interval. We document an initial increase in functional disparity in the Silurian that stabilized by the first stage of the Devonian, before the occurrence of an Emsian (∼400 Myr ago) oxygenation event implicated in the trophic radiation of vertebrates. Subsequent taxonomic diversification during the Devonian did not result in increased functional variation; instead, new taxa revisited and elaborated on established mandibular designs. Devonian functional space is dominated by lobe-finned fishes and 'placoderms'; high disparity within the latter implies considerable trophic innovation among jaw-bearing stem gnathostomes. By contrast, the major groups of living vertebrates--ray-finned fishes and tetrapods--show surprisingly conservative mandibular morphologies with little indication of functional diversification or innovation. Devonian gnathostomes reached a point where they ceased to accrue further mandibular functional disparity before becoming taxonomic dominants relative to 'ostracoderm

  5. Dosimetric effects of jaw tracking in step-and-shoot intensity-modulated radiation therapy.

    PubMed

    Joy, Sarah; Starkschall, George; Kry, Stephen; Salehpour, Mohammed; White, R Allen; Lin, Steven H; Balter, Peter

    2012-03-08

    The purpose of this work was to determine the dosimetric benefit to normal tissues by tracking the multi-leaf collimator (MLC) apertures with the photon jaws in step-and-shoot intensity-modulated radiation therapy (IMRT) on the Varian 2100 platform. Radiation treatment plans for ten thoracic, three pediatric, and three head and neck cancer patients were converted to plans with the jaws tracking each segment's MLC apertures, and compared to the original plans in a commercial radiation treatment planning system (TPS). The change in normal tissue dose was evaluated in the new plan by using the parameters V5, V10, and V20 (volumes receiving 5, 10 and 20 Gy, respectively) in the cumulative dose-volume histogram for the following structures: total lung minus gross target volume, heart, esophagus, spinal cord, liver, parotids, and brainstem. To validate the accuracy of our beam model, MLC transmission was measured and compared to that predicted by the TPS. The greatest changes between the original and new plans occurred at lower dose levels. In all patients, the reduction in V20 was never more than 6.3% and was typically less than 1%; the maximum reduction in V5 was 16.7% and was typically less than 3%. The variation in normal tissue dose reduction was not predictable, and we found no clear parameters that indicated which patients would benefit most from jaw tracking. Our TPS model of MLC transmission agreed with measurements with absolute transmission differences of less than 0.1% and, thus, uncertainties in the model did not contribute significantly to the uncertainty in the dose determination. We conclude that the amount of dose reduction achieved by collimating the jaws around each MLC aperture in step-and-shoot IMRT is probably not clinically significant.

  6. Jaw Intraosseous Lesions Biopsied Extracted From 1998 to 2010 in an Iranian Population

    PubMed Central

    Jamshidi, Shokoofeh; Shojaei, Setareh; Roshanaei, Ghodratollah; Modabbernia, Shirin; Bakhtiary, Esmaeel

    2015-01-01

    Background: Jaw bones might be potential locations for different lesions. Differences in prevalence and the type of lesions can help in designing and programming prevention procedures in health care centers. Objectives: The aim of the present study was to evaluate the prevalence of intraosseous lesions in the jaws of patients referred to diagnostic and therapeutic centers in Hamadan during 1990-2010. Patients and Methods: This cross-sectional descriptive analytical study was carried out in Hamadan in 2011. Data sheets of the subjects were used to collect all the data of patients with intraosseous lesions, including their age, gender, location of the lesion, the radiographic view of lesions, and their type and histopathological diagnoses. Data were analyzed with SPSS, using means and frequencies. Results: A total of 284 intraosseous lesions were reported in our study. The mean age of the subjects was 28.8 ± 15.2 years. The lesions were distributed in males and females almost similarly. The most prevalent lesions were cystic lesions (54.58%), manifestations of systemic conditions in jaw bones (18.3%), benign tumors (15.5%), malignant lesions (6.7%), and inflammatory lesions (4.92%), in a descending order. The most common cystic lesion was radicular cyst; the most common manifestation of systemic conditions in jaw bones was central giant cell granuloma; the most common benign tumor was ameloblastoma; the most common malignant lesion was osteosarcoma; and the most common inflammatory lesion was periapical granuloma. Conclusions: Our data provided information on the prevalence and types of intraosseous lesions among an Iranian population. This study provided baseline information to help in designing and programming procedures in health care centers in every community so that preventive therapeutic measures can be adopted. PMID:26328061

  7. Cerebral gigantism associated with jaw cyst basal cell naevoid syndrome in two families.

    PubMed

    Cramer, H; Niederdellmann, H

    1983-01-01

    We report 9 subjects from 2 families with the syndrome of cerebral gigantism, seven of the patients also had jaw cyst basal cell naevoid syndrome. Neurological, radiological, somatic and biochemical features of this hitherto unreported association are described. Neurological symptoms included mild hydrocephalus, ventricular malformation, cerebellar syndrome, intracranial calcification, oculomotor disturbances, EEG abnormalities and rarely, mild peripheral nervous disorders. A disturbance of calcium metabolism appears to be a prominent feature of the genetically determined nonprogressive syndrome.

  8. Cheiloscopy: A new role as a marker of sagittal jaw relation

    PubMed Central

    Kulkarni, Narayan; Vasudevan, SD; Shah, Romil; Rao, Parikshit; Balappanavar, Aswini Y

    2012-01-01

    Context: It has been proved that lip prints are analogous to thumb prints. A correlation between thumb prints and sagittal dental malocclusion has already been established. Soft tissue is gaining more importance in judgement of deformity or identity of a patient. Aim: To find a correlation between sagittal skeletal jaw relation and lip prints. Settings and Design: Descriptive, cross-sectional, comparative, single-blind, hospital-based study. Materials and Methods: A total of 90 patients were categorized into skeletal class I, class II, and class III, comprising 30 patients in each group with equal gender distribution. Dolphin imaging (10.5) software was used for analyzing sagittal jaw relation. Lip prints obtained from these 90 patients were analyzed. Statistical Analyses Used: Karl Pearson's correlation coefficient, Chi-square test, t-test, Spearman's co-efficient, analysis of variance (ANOVA). Results: It was observed that angle ANB (Angle formed between points nasion[N] to Subnasal[A] and nasion[N] to supramental [B]) and beta angle were statistically significant, revealing a strong negative correlation (-0.9060) with different classes of jaw relation. Significant difference was observed between genders in all the three classes. Significant difference was observed in relation to lip print and the quadrants of upper and lower lips. A statistical significance was noted on the right side of both upper and lower arches. Conclusion: This study shows that lip prints can be employed for sagittal jaw relation recognition. A further study on various ethnic backgrounds with a larger sample size in individual group is necessary for comparing lip prints and malocclusion. PMID:23087575

  9. Basal jawed vertebrate phylogeny inferred from multiple nuclear DNA-coded genes

    PubMed Central

    Kikugawa, Kanae; Katoh, Kazutaka; Kuraku, Shigehiro; Sakurai, Hiroshi; Ishida, Osamu; Iwabe, Naoyuki; Miyata, Takashi

    2004-01-01

    Background Phylogenetic analyses of jawed vertebrates based on mitochondrial sequences often result in confusing inferences which are obviously inconsistent with generally accepted trees. In particular, in a hypothesis by Rasmussen and Arnason based on mitochondrial trees, cartilaginous fishes have a terminal position in a paraphyletic cluster of bony fishes. No previous analysis based on nuclear DNA-coded genes could significantly reject the mitochondrial trees of jawed vertebrates. Results We have cloned and sequenced seven nuclear DNA-coded genes from 13 vertebrate species. These sequences, together with sequences available from databases including 13 jawed vertebrates from eight major groups (cartilaginous fishes, bichir, chondrosteans, gar, bowfin, teleost fishes, lungfishes and tetrapods) and an outgroup (a cyclostome and a lancelet), have been subjected to phylogenetic analyses based on the maximum likelihood method. Conclusion Cartilaginous fishes have been inferred to be basal to other jawed vertebrates, which is consistent with the generally accepted view. The minimum log-likelihood difference between the maximum likelihood tree and trees not supporting the basal position of cartilaginous fishes is 18.3 ± 13.1. The hypothesis by Rasmussen and Arnason has been significantly rejected with the minimum log-likelihood difference of 123 ± 23.3. Our tree has also shown that living holosteans, comprising bowfin and gar, form a monophyletic group which is the sister group to teleost fishes. This is consistent with a formerly prevalent view of vertebrate classification, although inconsistent with both of the current morphology-based and mitochondrial sequence-based trees. Furthermore, the bichir has been shown to be the basal ray-finned fish. Tetrapods and lungfish have formed a monophyletic cluster in the tree inferred from the concatenated alignment, being consistent with the currently prevalent view. It also remains possible that tetrapods are more closely

  10. Fusimotor influence on jaw muscle spindle activity during swallowing-related movements in the cat.

    PubMed

    Taylor, A; Hidaka, O; Durbaba, R; Ellaway, P H

    1997-08-15

    1. The activity patterns of muscle spindle afferents in jaw-closer muscles were studied during reflex swallowing movements in anaesthetized cats. Simultaneous records were made of the electromyogram (EMG) in masseter and anterior digastric muscles and of the unloaded jaw movements. The underlying patterns of fusimotor activity were deduced by comparing afferent discharges occurring during active swallowing with those occurring when exactly the same movements were imposed passively. The interpretation of spindle behaviour was greatly facilitated by characterizing the afferents according to the evidence for their contact with the various intrafusal muscle fibres, derived from testing with succinylcholine. It was also valuable to have two different types of afferent recorded simultaneously. 2. There was clear evidence of fusimotor activity occurring during active jaw closing so as to oppose the spindle silencing. This effect was most marked in b2c-type afferents (probably secondaries) and was therefore attributed to a modulation of static fusimotor discharge approximately in parallel with alpha-activity. 3. Afferents with evidence of bag1 fibre contacts (primaries) showed much greater sensitivity to muscle lengthening during active movement than when the movement was imposed. This difference was exaggerated when anaesthesia was deepened for the passive movements. This was interpreted as evidence for a higher level of dynamic fusimotor activity maintained during active movements than at rest. 4. The results support the view that for a variety of active jaw movements, static fusimotor neurone firing is modulated roughly in parallel with alpha-activity but leading it so as to counteract spindle unloading. Dynamic fusimotor neurone firing appears to be set at a raised level during active movements. Anaesthesia appears to depress activity in the alpha-motoneurones more than in gamma-motoneurones.

  11. Jaw mobility changes in patients with upper aerodigestive tract cancer undergoing radiation therapy

    PubMed Central

    Wienandts, Patrícia; Mozzini, Carolina; Pinto, Rosélie; da Motta, Neiro; Jotz, Geraldo

    2015-01-01

    Background Radiation therapy is a therapeutic modality widely used for treatment of upper aerodigestive tract (UADT) neoplasms. However, its action is not restricted to tumor cells, and it may cause a variety of adverse reactions, including reduced jaw mobility. Material and Methods A prospective cohort study was conducted to assess changes in jaw mobility in patients with UADT cancer undergoing radiation therapy. Results Fifty-six patients completed the study. The results showed a significant reduction in mouth opening (p<0.001), right lateral excursion (p=0.038) and left lateral excursion (p=0.035) of the jaw, a significant increase in the presence (p<0.001) and severity of oral mucositis (p<0.001), and a significant decrease in performance status (p<0.001) after radiation therapy. Thirty-six patients (64.3%) exhibited reduction in mouth opening after treatment. The variables significantly associated with mouth opening reduction on bivariate analysis were: modification of diet (p=0.037), radiation field (p=0.024), presence of mucositis (p=0.003), and reduction in performance status (p=0.007). After adjustment by the multivariate model, the only variables that remained significantly associated with reduction in mouth opening were presence of mucositis (p=0.018) and reduction in performance status (p=0.47). Conclusions These findings indicate that patients with upper aerodigestive tract cancer experience reduced jaw mobility after radiation therapy, which is strongly correlated with mucositis and reduced functional ability. Key words:Head and neck neoplasms, vertical dimension, radiation therapy, mucositis, temporomandibular joint, joint range of motion, trismus. PMID:26449427

  12. Molecular phylogenetics and diversification of trap-jaw ants in the genera Anochetus and Odontomachus (Hymenoptera: Formicidae).

    PubMed

    Larabee, Fredrick J; Fisher, Brian K; Schmidt, Chris A; Matos-Maraví, Pável; Janda, Milan; Suarez, Andrew V

    2016-10-01

    Ants in the genera Anochetus and Odontomachus belong to one of the largest clades in the subfamily Ponerinae, and are one of four lineages of ants possessing spring-loaded "trap-jaws." Here we present results from the first global species-level molecular phylogenetic analysis of these trap-jaw ants, reconstructed from one mitochondrial, one ribosomal RNA, and three nuclear protein-coding genes. Bayesian and likelihood analyses strongly support reciprocal monophyly for the genera Anochetus and Odontomachus. Additionally, we found strong support for seven trap-jaw ant clades (four in Anochetus and three in Odontomachus) mostly concordant with geographic distribution. Ambiguity remains concerning the closest living non-trap-jaw ant relative of the Anochetus+Odontomachus clade, but Bayes factor hypothesis testing strongly suggests that trap-jaw ants evolved from a short mandible ancestor. Ponerine trap-jaw ants originated in the early Eocene (52.5Mya) in either South America or Southeast Asia, where they have radiated rapidly in the last 30million years, and subsequently dispersed multiple times to Africa and Australia. These results will guide future taxonomic work on the group and act as a phylogenetic framework to study the macroevolution of extreme ant mouthpart specialization. PMID:27450781

  13. Intensity-modulated radiation therapy (IMRT) by a dynamic-jaws-only (DJO) technique in rotate-translate mode.

    PubMed

    Webb, S; Poludniowski, G

    2010-11-01

    In this note it is shown how the use of a rotate-translate methodology employing only jaws, which move dynamically with the beam continuously on, can lead to a delivery of a two-dimensional intensity-modulated beam wherein the modulation is spatially slowly varying. All that is necessary is that a pair of jaws sweep across the face of an accelerator with the aperture between them suitably varying in width and defined by a position-time trajectory function for each jaw. This is then repeated, at the same gantry angle, with the jaws rotated to a different head twist and with a different jaw-pair trajectory for a number of sequential head twists. The result of superposing the individual beams at the same gantry angle is a two-dimensional variation of fluence at this gantry angle. A powerful theorem is developed which shows that there is an infinity of jaw trajectories for some specified number of head twists, each of which corresponds to the same delivered two-dimensional modulated beam.

  14. Molecular phylogenetics and diversification of trap-jaw ants in the genera Anochetus and Odontomachus (Hymenoptera: Formicidae).

    PubMed

    Larabee, Fredrick J; Fisher, Brian K; Schmidt, Chris A; Matos-Maraví, Pável; Janda, Milan; Suarez, Andrew V

    2016-10-01

    Ants in the genera Anochetus and Odontomachus belong to one of the largest clades in the subfamily Ponerinae, and are one of four lineages of ants possessing spring-loaded "trap-jaws." Here we present results from the first global species-level molecular phylogenetic analysis of these trap-jaw ants, reconstructed from one mitochondrial, one ribosomal RNA, and three nuclear protein-coding genes. Bayesian and likelihood analyses strongly support reciprocal monophyly for the genera Anochetus and Odontomachus. Additionally, we found strong support for seven trap-jaw ant clades (four in Anochetus and three in Odontomachus) mostly concordant with geographic distribution. Ambiguity remains concerning the closest living non-trap-jaw ant relative of the Anochetus+Odontomachus clade, but Bayes factor hypothesis testing strongly suggests that trap-jaw ants evolved from a short mandible ancestor. Ponerine trap-jaw ants originated in the early Eocene (52.5Mya) in either South America or Southeast Asia, where they have radiated rapidly in the last 30million years, and subsequently dispersed multiple times to Africa and Australia. These results will guide future taxonomic work on the group and act as a phylogenetic framework to study the macroevolution of extreme ant mouthpart specialization.

  15. Comparative evaluation of reproducibility of peripheral tissues produced by different border molding materials in edentulous patients: An in vivo study

    PubMed Central

    Arora, Aman Kumar; Goyal, Itanshu; Sehgal, Monilka

    2015-01-01

    Aim: The aim of the study is to analyze the effect of different materials and techniques in current use on peripheral shaping of complete denture impression. Methods: The present study was conducted to compare and evaluate the maxillary border morphology produced using tissue conditioner as control and low fusing impression compound, Polyether, Pattern resin and periphery wax as border molding materials. The study was carried out on 15 denture wearer patients with well formed, rounded edentulous maxillary arch with adequate width and height. On each patient, border moldings were done, with tissue conditioner which was loaded on the borders of previous maxillary denture of the patient (control group), low fusing impression compound (Group 1), polyether (Group 2), Pattern resin (Group 3) and Peripheral wax (Group 4), respectively on special tray made for the patient. Sulcus width height and area was then measured for each group using stereomicroscope. Results and Conclusions: Based on the study it is concluded that the polyether was the best material for border molding which will give most accurate borders to a denture. PMID:26929495

  16. Systematic Assessment of the Various Controversies, Difficulties, and Current Trends in the Reestablishment of Lost Occlusal Planes in Edentulous Patients

    PubMed Central

    Sahoo, S; Singh, D; Raghav, D; Singh, G; Sarin, A; Kumar, P

    2014-01-01

    Accurate occlusal plane orientation is an essential factor in the fabrication of complete denture prosthesis. Over the years, it has received a number of methodologies by several researchers utilizing various anatomical landmarks however none of them is considered as perfect that could orient ideal occlusal plane. The presented literature review is an attempt to enlighten historical perspectives, pioneer researches, different controversies, difficulties and current trends for re-establishment of lost occlusal plane in edentulous patients. An extensive literature search was performed using Medline/PubMed interface and other scholarly research bibliographic databases using Medical Subject Headings. Studies describing research studies, case series and assorted clinical reports were retrieved and evaluated from 1963 to 2013. Most of the studies have suggest and evidence to consider Camper's plane for artificial orientation of occlusal plane however there is a substantial lack of genuine long term studies and authentic data that could recommend a single reliable landmark for perfect occlusal plane reorientation in a variety of cases. PMID:24971200

  17. Use of 4 immediately loaded zygomatic fixtures for retreatment of atrophic edentulous maxilla after complications of maxillary reconstruction.

    PubMed

    Kuabara, Marcos Rikio; Ferreira, Edilson José; Gulinelli, Jéssica Lemos; Panzarini, Sônia Regina

    2010-05-01

    This article reports the 20-month clinical outcome of the use of 4 zygomatic implants with immediate occlusal loading and reverse planning for the retreatment of atrophic edentulous maxilla after failed rehabilitation with autogenous bone graft reconstruction and maxillary implants. The intraoral clinical examination revealed mispositioned and loosened implants underneath a maxillary complete denture. The panoramic radiograph showed 6 maxillary implants. One implant was displaced into the right maxillary sinus, and the implant anchored in the region of tooth 21 was fractured. The other implants presented peri-implant bone loss. The implants anchored in the regions of teeth 21 to 23 and 11 to 13 were first removed. After 2 months, the reverse planning started with placement of 4 zygomatic fixtures, removal of the implants migrated into the sinus cavity and anchored in the region of tooth 17, and installation of a fixed denture. After 20 months of follow-up, no painful symptoms, peri-implant inflammation or infection, implant instability, or bone resorption was observed. The outcomes of this case confirm that the zygoma can offer a predictable anchorage and support function for a fixed denture in severely resorbed maxillae.

  18. Implant overdenture using a locator bar system by drill and tapping technique in a mandible edentulous patient: a case report.

    PubMed

    Kim, Min-Su; Yoon, Mi-Jung; Huh, Jung-Bo; Jeon, Young-Chan; Jeong, Chang-Mo

    2012-05-01

    Various options have been introduced for the selection of implant overdenture attachments. Attachment wear due to the repeated insertion and removal of dentures has caused problems such as decreased retention and the requirement for suprastructure remanufacturing. In these cases, a Locator bar system was applied using the drill and tapping technique to achieve total retrievability. In a 55-year-old female patient who showed three degrees of mobility in most of her teeth due to severe alveolar bone loss, a complete denture in the maxilla and an implant supported type overdenture in the mandible were planned after extracting all the remaining teeth. Six implants were placed from canine region to the distal molar region, and the locator was connected to the milled bar using the drill and tapping technique. For a 61-year-old female edentulous patient who complained of poor retention with old denture, a complete denture in the maxilla and an implant-tissue supported type overdenture in the mandible were planned. Four implants were placed in front of mental foramen, and the Locator was also connected to the Hader bar using the drill and tapping technique. With this technique, female parts can be easily replaced, and retention can be continuously maintained.

  19. The effect of mandibular setback or two-jaws surgery on pharyngeal airway among different genders.

    PubMed

    Degerliyurt, K; Ueki, K; Hashiba, Y; Marukawa, K; Simsek, B; Okabe, K; Nakagawa, K; Yamamoto, E

    2009-06-01

    Cephalometric studies show significant gender differences in the size of the pharyngeal airway space. This study aimed to investigate and compare morphologic changes after mandibular setback or two-jaws surgery on the pharyngeal airway in men and women using computed tomography (CT). The sample included 34 women and 13 men diagnosed with Class III skeletal deformities, who had been treated by mandibular setback or bimaxillary surgery (maxillary advancement and mandibular setback). Anteroposterior, lateral and cross-sectional area dimensions of the airway, at the level of soft palate and base of tongue, were measured pre- and postoperatively on CT images. In the mandibular setback group, the anteroposterior and cross-sectional area of the pharyngeal airway at the level of the soft palate and base of tongue were significantly reduced for men or women (P<.05). In the two-jaws surgery group, only midsagittal anteroposterior dimensions at the same levels were significantly decreased for men or women (P<.05). The difference between any values measured between men and women who received bilateral sagittal split ramus osteotomy setback surgery or two-jaws surgery for the treatment of class III anteroposterior discrepancy were not statistically significant (P>.05). This study suggests that oropharyngeal airway measurements, important for airway patency, do not demonstrate sex dimorphism.

  20. Variation in the shape and mechanical performance of the lower jaws in ceratopsid dinosaurs (Ornithischia, Ceratopsia).

    PubMed

    Maiorino, Leonardo; Farke, Andrew A; Kotsakis, Tassos; Teresi, Luciano; Piras, Paolo

    2015-11-01

    Ceratopsidae represents a group of quadrupedal herbivorous dinosaurs that inhabited western North America and eastern Asia during the Late Cretaceous. Although horns and frills of the cranium are highly variable across species, the lower jaw historically has been considered to be relatively conservative in morphology. Here, the lower jaws from 58 specimens representing 21 ceratopsoid taxa were sampled, using geometric morphometrics and 2D finite element analysis (FEA) to explore differences in morphology and mechanical performance across Ceratopsoidea (the clade including Ceratopsidae, Turanoceratops and Zuniceratops). Principal component analyses and non-parametric permuted manovas highlight Triceratopsini as a morphologically distinct clade within the sample. A relatively robust and elongate dentary, a larger and more elongated coronoid process, and a small and dorso-ventrally compressed angular characterize this clade, as well as the absolutely larger size. By contrast, non-triceratopsin chasmosaurines, Centrosaurini and Pachyrhinosaurini have similar morphologies to each other. Zuniceratops and Avaceratops are distinct from other taxa. No differences in size between Pachyrhinosaurini and Centrosaurini are recovered using non-parametric permuted anovas. Structural performance, as evaluated using a 2D FEA, is similar across all groups as measured by overall stress, with the exception of Triceratopsini. Shape, size and stress are phylogenetically constrained. A longer dentary as well as a long coronoid process result in a lower jaw that is reconstructed as relatively much more stressed in triceratopsins.

  1. Finite Element Analysis of the Cingulata Jaw: An Ecomorphological Approach to Armadillo's Diets.

    PubMed

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

    2014-01-01

    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

  2. Prediction of volumetric strain in the human temporomandibular joint cartilage during jaw movement

    PubMed Central

    Koolstra, J H; van Eijden, T M G J

    2006-01-01

    Human temporomandibular joint loading causes pressurization and flow of interstitial fluid in its cartilaginous structures. This largely determines its load-bearing and maintenance capacity. It was hypothesized that during cyclical jaw movements normal pressure distribution dynamics would enable fluid to reach all necessary cartilage regions. This was tested qualitatively by analysis of local volumetric strain dynamics during jaw open–close movements predicted by a dynamic model of the human masticatory system. Finite-element analysis was performed in separate regions of the articular cartilage layers and articular disc. Heterogeneous patterns of dilatation and compression were predicted. Compression was found to be more dominant during jaw closing than opening. The pressure gradient in the superior layer of the articular disc was more mediolaterally orientated than in its inferior layer. The findings suggest that, where necessary, regionally the cartilage can imbibe fluid to protect the subchondral bone from impact loads effectively. In the disc itself presumably all areas receive regular refreshment of interstitial fluid. PMID:16928205

  3. Processing system of jaws tomograms for pathology identification and surgical guide modeling

    NASA Astrophysics Data System (ADS)

    Putrik, M. B.; Lavrentyeva, Yu. E.; Ivanov, V. Yu.

    2015-11-01

    The aim of the study is to create an image processing system, which allows dentists to find pathological resorption and to build surgical guide surface automatically. X-rays images of jaws from cone beam tomography or spiral computed tomography are the initial data for processing. One patient's examination always includes up to 600 images (or tomograms), that's why the development of processing system for fast automation search of pathologies is necessary. X-rays images can be useful not for only illness diagnostic but for treatment planning too. We have studied the case of dental implantation - for successful surgical manipulations surgical guides are used. We have created a processing system that automatically builds jaw and teeth boundaries on the x-ray image. After this step, obtained teeth boundaries used for surgical guide surface modeling and jaw boundaries limit the area for further pathologies search. Criterion for the presence of pathological resorption zones inside the limited area is based on statistical investigation. After described actions, it is possible to manufacture surgical guide using 3D printer and apply it in surgical operation.

  4. Multimodality treatment of osteosarcoma of the jaw: a single institution experience.

    PubMed

    Ferrari, Daris; Codecà, Carla; Battisti, Nicolò; Broggio, Francesca; Crepaldi, Francesca; Violati, Martina; Bertuzzi, Cecilia; Dottorini, Lorenzo; Caldiera, Sarah; Luciani, Andrea; Moneghini, Laura; Biglioli, Federico; Cassinelli, Gabriela; Morabito, Alberto; Foa, Paolo

    2014-09-01

    Osteosarcomas of the jaws are rare mesenchymal tumors frequently diagnosed in the fourth decade of life which account for 6 % of all osteosarcomas. This study evaluated the efficacy on the patients outcome of multimodality treatment consisting of surgery, chemotherapy and radiotherapy. The records of 22 patients affected by jaw osteosarcoma treated with a combination of surgery, poly-chemotherapy and adjuvant radiotherapy in selected cases were reviewed. Response rate, progression-free survival and overall survival were evaluated. Neoadjuvant chemotherapy resulted in an overall response rate of 83.3 %, necrosis of grade I or II was obtained, respectively, in 44.4 and 55.6 % of the patients, and surgery was radical in all patients. At a median follow-up of 60 months, the 5-year progression-free survival and overall survival were 73.5 and 77.4 %, respectively. These outcome parameters significantly correlated with age at diagnosis and grade of chemotherapy-induced necrosis. A complex multimodality approach including chemotherapy and radiotherapy, along with radical surgery, can maximize the outcome of patients affected by osteosarcoma of the jaws.

  5. 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

  6. Processing system of jaws tomograms for pathology identification and surgical guide modeling

    SciTech Connect

    Putrik, M. B. Ivanov, V. Yu.; Lavrentyeva, Yu. E.

    2015-11-17

    The aim of the study is to create an image processing system, which allows dentists to find pathological resorption and to build surgical guide surface automatically. X-rays images of jaws from cone beam tomography or spiral computed tomography are the initial data for processing. One patient’s examination always includes up to 600 images (or tomograms), that’s why the development of processing system for fast automation search of pathologies is necessary. X-rays images can be useful not for only illness diagnostic but for treatment planning too. We have studied the case of dental implantation – for successful surgical manipulations surgical guides are used. We have created a processing system that automatically builds jaw and teeth boundaries on the x-ray image. After this step, obtained teeth boundaries used for surgical guide surface modeling and jaw boundaries limit the area for further pathologies search. Criterion for the presence of pathological resorption zones inside the limited area is based on statistical investigation. After described actions, it is possible to manufacture surgical guide using 3D printer and apply it in surgical operation.

  7. Bisphosphonate-related osteonecrosis of the jaw: data from the French national pharmacovigilance database.

    PubMed

    de Boissieu, Paul; Gaboriau, Louise; Morel, Aurore; Trenque, Thierry

    2016-10-01

    The aim of this study was to describe bisphosphonate-related osteonecrosis of the jaw (BRONJ) in the French national pharmacovigilance database. BRONJ was identified with the standardized MedDRA query (SMQ) 'osteonecrosis' among all data from 1985 to 31 December 2014. Because this SMQ was not specific to the jaw localization, selection of cases based on anatomy was performed after data extraction. For each case, demographic and medical information was analysed, as well as data about notification (year of notification, year of occurrence, outcome, seriousness). Known associated factors for BRONJ were also documented: dentoalveolar surgery, glucocorticoids, chemotherapy, anti-angiogenics, denosumab. Among 1404 SMQ notifications, 663 were located in the jaws and 629 were associated with bisphosphonate use. BRONJ reported in the database mainly affected women (n = 443, 71%) with an oncological indication (n = 440, 70%). BRONJ was considered as serious in 91%. Outcome was unfavourable for 92% of cases. Associated factors were identified for 70% of the patients. A peak of notification was noted in 2014 (13% of all cases), but on analysis by year of occurrence instead of by year of notification, this peak disappeared. SMQ 'osteonecrosis' appears to be an adequate tool to analyse BRONJ in a pharmacovigilance database. PMID:27315575

  8. [Effect of vincristine on molar development and jaw growth in rats].

    PubMed

    Sedlecki, S; Jakovljević, A; Pap, K

    1989-01-01

    A cystostatic of group Vinca-alcaloides, Vincristine, is often used in chemotherapy. As a microtubular poison it reacts with microtubular molecules of cell cytoplasma and in response to dose administrated decelerates or stops cell division. Since the information about the effect of this drug on molar teeth has not been found in available literature the aim of this study was to investigate the effect of vincristine on tooth development and jaw growth in rats. The experiment was carried out on Wistar rats of both sexes. Vincristine (Oncovin, "Lilly") was injected to animals in the dose of 0.1 mg/kg b.w. seven or eight days following birth. Treated and control animals were sacrificed on the 24th postnatal day. Radiographs of the mandibule were used to study tooth development. The morphometric examination concerned the following parameters: in maxillar frontal and posterior arc width and height; vertical and sagital dimension as well as length of incisive crown in the mandibule. The results of the analysis suggested that the teeth of treated rats were retarded in development compared to the control animals. Morphometric investigations showed that in treated rats both jaws were decelerated in growth in comparison to the control group but with no statistical significance. It should be emphasized that a 16-day-period was too short that full efficet of Vincristine should be established in rats and lead to a result which could suggest a certain molar development and jaw growth.

  9. Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions.

    PubMed

    Mortazavi, Hamed; Baharvand, Maryam; Rahmani, Somayeh; Jafari, Soudeh; Parvaei, Parvin

    2015-12-01

    In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as "jaw disease," "jaw lesions," "radiolucent rim," "radiolucent border," and "radiolucent halo." More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs. PMID:26730374

  10. Finite Element Analysis of the Cingulata Jaw: An Ecomorphological Approach to Armadillo's Diets.

    PubMed

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

    2014-01-01

    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.

  11. Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions

    PubMed Central

    Mortazavi, Hamed; Rahmani, Somayeh; Jafari, Soudeh; Parvaei, Parvin

    2015-01-01

    In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as "jaw disease," "jaw lesions," "radiolucent rim," "radiolucent border," and "radiolucent halo." More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs. PMID:26730374

  12. Esthetic rehabilitation of single anterior edentulous space using fiber-reinforced composite

    PubMed Central

    Kim, Hyeon; Song, Min-Ju; Shin, Su-Jung; Lee, Yoon

    2014-01-01

    A fiber-reinforced composite (FRC) fixed prosthesis is an innovative alternative to a traditional metal restoration, as it is a conservative treatment method. This case report demonstrates a detailed procedure for restoring a missing anterior tooth with an FRC. A 44-year-old woman visited our department with an avulsed tooth that had fallen out on the previous day and was completely dry. This tooth was replanted, but it failed after one year. A semi-direct technique was used to fabricate a FRC fixed partial prosthesis for its replacement. The FRC framework and the pontic were fabricated using a duplicated cast model and nanofilled composite resin. Later on, interproximal contact, tooth shape, and shade were adjusted at chairside. This technique not only enables the clinician to replace a missing tooth immediately after extraction for minimizing esthetic problems, but it also decreases both tooth reduction and cost. PMID:25110647

  13. Panostotic expansile bone disease with massive jaw tumor formation and a novel mutation in the signal peptide of RANK.

    PubMed

    Schafer, Anne L; Mumm, Steven; El-Sayed, Ivan; McAlister, William H; Horvai, Andrew E; Tom, Andrea M; Hsiao, Edward C; Schaefer, Frederick V; Collins, Michael T; Anderson, Mark S; Whyte, Michael P; Shoback, Dolores M

    2014-04-01

    Precise regulation of bone resorption is critical for skeletal homeostasis. We report a 32-year-old man with a panostotic expansile bone disease and a massive hemorrhagic mandibular tumor. Originally from Mexico, he was deaf at birth and became bow-legged during childhood. There was no family history of skeletal disease. Puberty occurred normally, but during adolescence he experienced difficulty straightening his limbs, sustained multiple fractures, and developed a bony tumor on his chin. By age 18 years, all limbs were misshapen. The mandibular mass grew and protruded from the oral cavity, extending to the level of the lower ribs. Other bony defects included a similar maxillary mass and serpentine limbs. Upon referral at age 27 years, biochemical studies showed serum alkaline phosphatase of 1760 U/L (Nl: 29-111) and other elevated bone turnover markers. Radiography of the limbs showed medullary expansion and cortical thinning with severe bowing. Although the jaw tumors were initially deemed inoperable, mandibular mass excision and staged partial maxillectomy were eventually performed. Tumor histopathology showed curvilinear trabeculae of woven bone on a background of hypocellular fibrous tissue. Fibrous dysplasia of bone was suspected, but there was no mutation in codon 201 of GNAS in samples from blood or tumor. His clinical and radiographic findings, elevated serum markers, and disorganized bone morphology suggested amplified receptor activator of NF-κB (RANK) signaling, even though his disorder differed from conditions with known constitutive activation of RANK signaling (eg, familial expansile osteolysis). We found a unique 12-base pair duplication in the signal peptide of TNFRSF11A, the gene that encodes RANK. No exon or splice site mutations were found in the genes encoding RANK ligand or osteoprotegerin. Alendronate followed by pamidronate therapies substantially decreased his serum alkaline phosphatase activity. This unique patient expands the

  14. Panostotic Expansile Bone Disease With Massive Jaw Tumor Formation and a Novel Mutation in the Signal Peptide of RANK

    PubMed Central

    Schafer, Anne L; Mumm, Steven; El-Sayed, Ivan; McAlister, William H; Horvai, Andrew E; Tom, Andrea M; Hsiao, Edward C; Schaefer, Frederick V; Collins, Michael T; Anderson, Mark S; Whyte, Michael P; Shoback, Dolores M

    2015-01-01

    Precise regulation of bone resorption is critical for skeletal homeostasis. We report a 32-year-old man with a panostotic expansile bone disease and a massive hemorrhagic mandibular tumor. Originally from Mexico, he was deaf at birth and became bow-legged during childhood. There was no family history of skeletal disease. Puberty occurred normally, but during adolescence he experienced difficulty straightening his limbs, sustained multiple fractures, and developed a bony tumor on his chin. By age 18 years, all limbs were misshapen. The mandibular mass grew and protruded from the oral cavity, extending to the level of the lower ribs. Other bony defects included a similar maxillary mass and serpentine limbs. Upon referral at age 27 years, biochemical studies showed serum alkaline phosphatase of 1760 U/L (Nl: 29-111) and other elevated bone turnover markers. Radiography of the limbs showed medullary expansion and cortical thinning with severe bowing. Although the jaw tumors were initially deemed inoperable, mandibular mass excision and staged partial maxillectomy were eventually performed. Tumor histopathology showed curvilinear trabeculae of woven bone on a background of hypocellular fibrous tissue. Fibrous dysplasia of bone was suspected, but there was no mutation in codon 201 of GNAS in samples from blood or tumor. His clinical and radiographic findings, elevated serum markers, and disorganized bone morphology suggested amplified receptor activator of NF-κB (RANK) signaling, even though his disorder differed from conditions with known constitutive activation of RANK signaling (eg, familial expansile osteolysis). We found a unique 12-base pair duplication in the signal peptide of TNFRSF11A, the gene that encodes RANK. No exon or splice site mutations were found in the genes encoding RANK ligand or osteoprotegerin. Alendronate followed by pamidronate therapies substantially decreased his serum alkaline phosphatase activity. This unique patient expands the phenotypes

  15. The globin gene repertoire of lampreys: convergent evolution of hemoglobin and myoglobin in jawed and jawless vertebrates.

    PubMed

    Schwarze, Kim; Campbell, Kevin L; Hankeln, Thomas; Storz, Jay F; Hoffmann, Federico G; Burmester, Thorsten

    2014-10-01

    Agnathans (jawless vertebrates) occupy a key phylogenetic position for illuminating the evolution of vertebrate anatomy and physiology. Evaluation of the agnathan globin gene repertoire can thus aid efforts to reconstruct the origin and evolution of the globin genes of vertebrates, a superfamily that includes the well-known model proteins hemoglobin and myoglobin. Here, we report a comprehensive analysis of the genome of the sea lamprey (Petromyzon marinus) which revealed 23 intact globin genes and two hemoglobin pseudogenes. Analyses of the genome of the Arctic lamprey (Lethenteron camtschaticum) identified 18 full length and five partial globin gene sequences. The majority of the globin genes in both lamprey species correspond to the known agnathan hemoglobins. Both genomes harbor two copies of globin X, an ancient globin gene that has a broad phylogenetic distribution in the animal kingdom. Surprisingly, we found no evidence for an ortholog of neuroglobin in the lamprey genomes. Expression and phylogenetic analyses identified an ortholog of cytoglobin in the lampreys; in fact, our results indicate that cytoglobin is the only orthologous vertebrate-specific globin that has been retained in both gnathostomes and agnathans. Notably, we also found two globins that are highly expressed in the heart of P. marinus, thus representing functional myoglobins. Both genes have orthologs in L. camtschaticum. Phylogenetic analyses indicate that these heart-expressed globins are not orthologous to the myoglobins of jawed vertebrates (Gnathostomata), but originated independently within the agnathans. The agnathan myoglobin and hemoglobin proteins form a monophyletic group to the exclusion of functionally analogous myoglobins and hemoglobins of gnathostomes, indicating that specialized respiratory proteins for O2 transport in the blood and O2 storage in the striated muscles evolved independently in both lineages. This dual convergence of O2-transport and O2-storage proteins in

  16. Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues

    PubMed Central

    Gan, Ning; Xiong, Yaoyang; Jiao, Ting

    2016-01-01

    Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0

  17. Effect of jaw size in megavoltage CT on image quality and dose

    SciTech Connect

    Jung, Jae Hong; Cho, Kwang Hwan; Kim, Yong Ho; Moon, Seong Kwon; Min, Chul Kee; Kim, Woo Chul; Kim, Eun Seog; Chang, Ah Ram; Kim, Tae Ho; Yoon, Jai-Woong; Suh, Tae-Suk; Huh, Hyun Do

    2012-08-15

    Purpose: Recently, the jaw size for the TomoTherapy Hi-Art II{sup Registered-Sign} (TomoTherapy Inc., Madison, WI) was reduced from 4 mm (J4) to 1 mm (J1) to improve the longitudinal (IEC-Y) resolution in megavoltage computed tomography (MVCT) images. This study evaluated the effect of jaw size on the image quality and dose, as well as the dose delivered to the lens of the eye, which is a highly radiosensitive tissue. Methods: MVCT image quality (image noise, uniformity, contrast linearity, high-contrast resolution, and full width at half-maximum) and multiple scan average dose (MSAD) were measured at different jaw sizes. A head phantom and photoluminescence glass dosimeters (PLDs) were used to measure the exposed lens dose (cGy). Different MVCT scan modes (pitch = 1, 2, and 3) and scan lengths (108 mm, 156 mm, and 204 mm) were applied in the MSAD and PLDs measurements. Results: The change in jaw size from J4 to J1 produced no change or only a slight improvement in image noise, uniformity, contrast linearity, and high-contrast resolution. However, the full-width at half-maximum reduced from approximately 7.2 at J4 to 4.5 mm at J1, which represents an enhancement in the longitudinal resolution. The MSAD at the center point changed from approximately 0.69-2.32 cGy (peripheral: 0.83-2.49 cGy) at J4 to 0.85-2.81 cGy (peripheral: 1.05-2.86 cGy) at J1. The measured lens dose increased from 0.92-3.36 cGy at J4 to 1.06-3.91 cGy at J1. Conclusions: The change in jaw size improved longitudinal resolution. The MVCT imaging dose of approximately 3.86 cGy, 1.92 cGy, and 1.22 cGy was delivered at a pitch of 1, 2, and 3, respectively, per fraction in the head and neck treatment plans. Therefore, allowance for an approximately 15% increase in lens dose over that with J4 should be provided with J1.

  18. Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

    PubMed

    Gan, Ning; Xiong, Yaoyang; Jiao, Ting

    2016-01-01

    Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0

  19. Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

    PubMed

    Gan, Ning; Xiong, Yaoyang; Jiao, Ting

    2016-01-01

    Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0

  20. Jaw1/LRMP, a germinal centre-associated marker for the immunohistological study of B-cell lymphomas.

    PubMed

    Tedoldi, S; Paterson, J C; Cordell, J; Tan, S-Y; Jones, M; Manek, S; Dei Tos, A P; Roberton, H; Masir, N; Natkunam, Y; Pileri, S A; Facchetti, F; Hansmann, M-L; Mason, D Y; Marafioti, T

    2006-08-01

    Jaw1, also known as lymphoid-restricted membrane protein (LRMP), is an endoplasmic reticulum-associated protein. High levels of Jaw1/LRMP mRNA have been found in germinal centre B-cells and in diffuse large B-cell lymphomas of 'germinal centre' subtype. This paper documents Jaw1/LRMP expression at the protein level in human tissues by immunohistochemical and western blotting analysis using an antibody reactive with paraffin-embedded tissues. Jaw1/LRMP was highly expressed in germinal centre B-cells (in keeping with gene expression data), in 'monocytoid B-cells', and in splenic marginal zone B-cells. It was absent, or present at only low levels, in mature T-cells, although cortical thymocytes were weakly positive. Among lymphoid neoplasms, Jaw1/LRMP was found in germinal centre-derived lymphomas (follicle centre lymphoma, Burkitt's lymphoma, lymphocyte-predominant Hodgkin's disease) but not in T-cell neoplasms (with the exception of a single T lymphoblastic lymphoma). Classical Hodgkin's disease and myeloma lacked Jaw1/LRMP but many cases of chronic lymphocytic leukaemia (but not mantle zone lymphoma) were Jaw1/LRMP-positive. Approximately half of the marginal zone lymphomas were Jaw1/LRMP-positive. In diffuse large B-cell lymphomas, Jaw1/LRMP was found in three-quarters (24/32) of the cases classified phenotypically as being of 'germinal centre' type, but it was also expressed in almost half (13/28) of the 'non-germinal centre' cases. A similar proportion of 'non-germinal centre' cases were positive for the protein products of two other genes expressed highly in germinal centre cells (HGAL/GCET2 and PAG). The fact that all three of these proteins are expressed in a significant proportion of diffuse large B-cell lymphomas assigned to the 'non-germinal centre' category indicates that the immunophenotypic categorization of diffuse large B-cell lymphoma according to cellular origin may be more complicated than currently understood. Finally, the expression of Jaw1/LRMP

  1. Twisted partially pure spinors

    NASA Astrophysics Data System (ADS)

    Herrera, Rafael; Tellez, Ivan

    2016-08-01

    Motivated by the relationship between orthogonal complex structures and pure spinors, we define twisted partially pure spinors in order to characterize spinorially subspaces of Euclidean space endowed with a complex structure.

  2. Development of the trigeminal motor neurons in parrots: implications for the role of nervous tissue in the evolution of jaw muscle morphology.

    PubMed

    Tokita, Masayoshi; Nakayama, Tomoki

    2014-02-01

    Vertebrates have succeeded to inhabit almost every ecological niche due in large part to the anatomical diversification of their jaw complex. As a component of the feeding apparatus, jaw muscles carry a vital role for determining the mode of feeding. Early patterning of the jaw muscles has been attributed to cranial neural crest-derived mesenchyme, however, much remains to be understood about the role of nonneural crest tissues in the evolution and diversification of jaw muscle morphology. In this study, we describe the development of trigeminal motor neurons in a parrot species with the uniquely shaped jaw muscles and compare its developmental pattern to that in the quail with the standard jaw muscles to uncover potential roles of nervous tissue in the evolution of vertebrate jaw muscles. In parrot embryogenesis, the motor axon bundles are detectable within the muscular tissue only after the basic shape of the muscular tissue has been established. This supports the view that nervous tissue does not primarily determine the spatial pattern of jaw muscles. In contrast, the trigeminal motor nucleus, which is composed of somata of neurons that innervate major jaw muscles, of parrot is more developed compared to quail, even in embryonic stage where no remarkable interspecific difference in both jaw muscle morphology and motor nerve branching pattern is recognized. Our data suggest that although nervous tissue may not have a large influence on initial patterning of jaw muscles, it may play an important role in subsequent growth and maintenance of muscular tissue and alterations in cranial nervous tissue development may underlie diversification of jaw muscle morphology.

  3. Functional morphology of jaw trabeculation in the lesser electric ray Narcine brasiliensis, with comments on the evolution of structural support in the Batoidea.

    PubMed

    Dean, Mason N; Huber, Daniel R; Nance, Holly A

    2006-10-01

    The design of minimum-weight structures that retain their integrity under dynamic loading regimes has long challenged engineers. One solution to this problem found in both human and biological design is the optimization of weight and strength by hollowing a structure and replacing its inner core with supportive struts. In animals, this design is observed in sand dollar test, avian beak, and the cancellous bone of tetrapod limbs. Additionally, within the elasmobranch fishes, mineralized trabeculae (struts) have been reported in the jaws of durophagous myliobatid stingrays (Elasmobranchii: Batoidea), but were believed to be absent in basal members of the batoid clade. This study, however, presents an additional case of batoid trabeculation in the lesser electric ray, Narcine brasiliensis (Torpediniformes). The trabeculae in these species likely play different functional roles. Stingrays use their reinforced jaws to crush bivalves, yet N. brasiliensis feeds by ballistically protruding its jaws into the sediment to capture polychaetes. In N. brasiliensis, trabeculae are localized to areas likely to experience the highest load: the quadratomandibular jaw joints, hyomandibular-cranial joint, and the thinnest sections of the jaws immediately lateral to the symphyses. However, the supports perform different functions dependent on location. In regions where the jaws are loaded transversely (as in durophagous rays), "load leading" trabeculae distribute compressive forces from the cortex through the lumen of the jaws. In the parasymphyseal regions of the jaws, "truss" trabeculae form cross-braces perpendicular to the long axes of the jaws. At peak protrusion, the jaw arch is medially compressed and the jaw loaded axially such that these trabeculae are positioned to resist buckling associated with excavation forces. "Truss" trabeculae function to maintain the second moment of area in the thinnest regions of the jaws, illustrating a novel function for batoid trabeculation. Thus

  4. The Validity of Claims-Based Algorithms to Identify Serious Hypersensitivity Reactions and Osteonecrosis of the Jaw.

    PubMed

    Wright, Nicole C; Curtis, Jeffrey R; Arora, Tarun; Smith, Wilson K; Kilgore, Meredith L; Saag, Kenneth G; Safford, Monika M; Delzell, Elizabeth S

    2015-01-01

    Validation of claims-based algorithms to identify serious hypersensitivity reactions and osteonecrosis of the jaw has not been performed in large osteoporosis populations. The objective of this project is to estimate the positive predictive value of the claims-based algorithms in older women with osteoporosis enrolled in Medicare. Using the 2006-2008 Medicare 5% sample data, we identified potential hypersensitivity and osteonecrosis of the jaw cases based on ICD-9 diagnosis codes. Potential hypersensitivity cases had a 995.0, 995.2, or 995.3 diagnosis code on emergency department or inpatient claims. Potential osteonecrosis of the jaw cases had ≥1 inpatient or outpatient physician claim with a 522.7, 526.4, 526.5, or 733.45 diagnosis code or ≥2 claims of any type with a 526.9 diagnosis code. All retrieved records were redacted and reviewed by experts to determine case status: confirmed, not confirmed, or insufficient information. We calculated the positive predictive value as the number of confirmed cases divided by the total number of retrieved records with sufficient information. We requested 412 potential hypersensitivity and 304 potential osteonecrosis of the jaw records and received 174 (42%) and 84 (28%) records respectively. Of 84 potential osteonecrosis of the jaw cases, 6 were confirmed, resulting in a positive predictive value (95% CI) of 7.1% (2.7, 14.9). Of 174 retrieved potential hypersensitivity records, 95 were confirmed. After exclusion of 25 records with insufficient information for case determination, the overall positive predictive value (95% CI) for hypersensitivity reactions was 76.0% (67.5, 83.2). In a random sample of Medicare data, a claim-based algorithm to identify serious hypersensitivity reactions performed well. An algorithm for osteonecrosis of the jaw did not, partly due to the inclusion of diagnosis codes that are not specific for osteoporosis of the jaw.

  5. Metastatic tumors in the jaw bones: A retrospective clinicopathological study of 12 cases at Tertiary Cancer Center

    PubMed Central

    Nawale, Kundan Kisanrao; Vyas, Monika; Kane, Shubhada; Patil, Asawari

    2016-01-01

    Introduction: The metastatic disease of the jaw bones is very uncommon and accounts for approximately 1% of all malignancies of jaw. The most common location is molar region of mandible. Metastasis may go undetected on a routine skeletal survey for assessment of metastasis and rarely includes jaw bones. Aims and Objective: The aim of the study is to analyze primary malignancies in metastatic jaw tumors. Materials and Methods: We retrospectively studied clinicopathological features of 12 patients of metastasis to jaw bones diagnosed at tertiary cancer center between 2003 and 2011. All H and E and immunohistochemical slides were reviewed by two pathologists and relevant details were noted. Results: There were eight female and four male patients, with age range 12–71 years with metastases to jaws. All of them involved mandible with one case also showing the involvement of frontal sinuses. The types of metastatic tumors include adenocarcinoma (six cases), papillary thyroid carcinoma (four cases), carcinoma with neuroendocrine differentiation (one case) and neuroblastoma (one case). The diagnosis was made on biopsies in eight cases and on hemimandibulectomy in four cases. The primary site was known at the time of presentation only in four cases, all of them being thyroid carcinomas. Primary site was determined in seven cases after immunohistochemical workup on metastatic tumor and further investigations, whereas the primary site of carcinoma with neuroendocrine differentiation was unknown. Conclusion: Metastasis to jaw bones is rare and may be the first manifestation of unknown primary. A lesion predominantly involving bone with unusual morphology should raise a possibility of metastasis. PMID:27601818

  6. Analysis of Relative Parallelism Between Hamular-Incisive-Papilla Plane and Campers Plane in Edentulous Subjects: A Comparative Study.

    PubMed

    Tambake, Deepti; Shetty, Shilpa; Satish Babu, C L; Fulari, Sangamesh G

    2014-12-01

    The study was undertaken to evaluate the parallelism between hamular-incisive-papilla plane (HIP) and the Campers plane. And to determine which part of the posterior reference of the tragus i.e., the superior, middle or the inferior of the Camper's plane is parallel to HIP using digital lateral cephalograms. Fifty edentulous subjects with well formed ridges were selected for the study. The master casts were obtained using the standard selective pressure impression procedure. On the deepest point of the hamular notches and the centre of the incisive papilla stainless steel spherical bearings were glued to the cast at the marked points. The study templates were fabricated with autopolymerizing acrylic resin. The subjects were prepared for the lateral cephalograms. Stainless steel spherical bearings were adhered to the superior, middle, inferior points of the tragus of the ear and inferior border of the ala of the nose using surgical adhesive tape. The subjects with study templates were subjected to lateral cephalograms. Cephalometric tracings were done using Autocad 2010 software. Lines were drawn connecting the incisive papilla and hamular notch and the stainless steel spherical bearings placed on the superior, middle and inferior points on the tragus and the ala of the nose i.e., the Campers line S, Campers line M, Campers line I. The angles between the three Camper's line and the HIP were measured and recorded. Higher mean angulation was recorded in Campers line S -HIP (8.03) followed by Campers line M-HIP (4.60). Campers line I-HIP recorded the least angulation (3.80). The HIP is parallel to the Camper's plane. The Camper's plane formed with the posterior reference point as inferior point of the tragus is relatively parallel to the HIP. PMID:26199503

  7. Comparative evaluation of border molding, using two different techniques in maxillary edentulous arches - An in vivo study

    PubMed Central

    Yarapatineni, Rameshbabu; Vilekar, Abhishek; Kumar, J Phani; Kumar, G Ajay; Aravind, Prasad; Kumar, P Anil

    2013-01-01

    Background: This study was undertaken to compare the retention between sectional border molding using low fusing greenstick compound and single step border molding using condensation silicone (putty) impression material in three stages- A. Immediately following border molding, B. After final impression and C. With the finished permanent denture base. Materials & Methods: In this study evaluation of retentive values of sectional border molding (Group I) (custom impression trays border molded with green stick compound ) and single step border molding (Group II) ( border molding with condensation silicone (putty) impression material ). In both techniques definitive wash impression were made with light body condensation silicone and permanent denture base with heat cure polymerization resin. Results: Group II was significantly higher (mean=8011.43) than Group I (mean=5777.43) in test-A. The t-value (1.5883) infers that there was significant difference between Group I and Group II (p =0.15). Group I was significantly higher (mean=6718.57) than Group II (mean=5224.29) in test -B. The t-value (1.6909) infers that there was significant difference between Group I and Group II (p=0.17). Group II was higher (mean=4025.14) than Group I (mean=3835.07) in test -C. The t-value was 0.1239. But it was found to be statistically insignificant (p=0.005). Conclusion: Within the limitation of this clinical study border molding custom tray with low fusing green stick compound provided similar retention as compared to custom impression tray with condensation silicone in permanent denture base. How to cite this article: Yarapatineni R, Vilekar A, Kumar JP, Kumar GA, Aravind P, Kumar PA. Comparative evaluation of border molding, using two different techniques in maxillary edentulous arches - An in vivo study. J Int Oral Health 2013; 5(6):82-7 . PMID:24453450

  8. Analysis of Relative Parallelism Between Hamular-Incisive-Papilla Plane and Campers Plane in Edentulous Subjects: A Comparative Study.

    PubMed

    Tambake, Deepti; Shetty, Shilpa; Satish Babu, C L; Fulari, Sangamesh G

    2014-12-01

    The study was undertaken to evaluate the parallelism between hamular-incisive-papilla plane (HIP) and the Campers plane. And to determine which part of the posterior reference of the tragus i.e., the superior, middle or the inferior of the Camper's plane is parallel to HIP using digital lateral cephalograms. Fifty edentulous subjects with well formed ridges were selected for the study. The master casts were obtained using the standard selective pressure impression procedure. On the deepest point of the hamular notches and the centre of the incisive papilla stainless steel spherical bearings were glued to the cast at the marked points. The study templates were fabricated with autopolymerizing acrylic resin. The subjects were prepared for the lateral cephalograms. Stainless steel spherical bearings were adhered to the superior, middle, inferior points of the tragus of the ear and inferior border of the ala of the nose using surgical adhesive tape. The subjects with study templates were subjected to lateral cephalograms. Cephalometric tracings were done using Autocad 2010 software. Lines were drawn connecting the incisive papilla and hamular notch and the stainless steel spherical bearings placed on the superior, middle and inferior points on the tragus and the ala of the nose i.e., the Campers line S, Campers line M, Campers line I. The angles between the three Camper's line and the HIP were measured and recorded. Higher mean angulation was recorded in Campers line S -HIP (8.03) followed by Campers line M-HIP (4.60). Campers line I-HIP recorded the least angulation (3.80). The HIP is parallel to the Camper's plane. The Camper's plane formed with the posterior reference point as inferior point of the tragus is relatively parallel to the HIP.

  9. An Analysis of Visibility and Anatomic Variations of Mandibular Canal in Digital Panoramic Radiographs of Dentulous and Edentulous Patients in Northern Iran Populations

    PubMed Central

    Nemati, Somayeh; Ashouri Moghadam, Anahita; Dalili Kajan, Zahra; Mohtavipour, Seyedeh Tahereh; Amouzad, Hasan

    2016-01-01

    Statement of the Problem Insufficient information about the anatomical positions and structure of mandibular canal provokes unwanted damage to this important structure of mandible. Purpose The aim of this study was to determine the visibility and anatomical variations of mandibular canal in digital panoramic radiographs of dentulous and edentulous patients in a sample of Iranian population. Materials and Method In this retrospective-analytical research, 249 digital panoramic radiographs in dentulous group and 126 in edentulous group were studied by an expert oral and maxillofacial radiologist. In both groups, the visibility of canal borders in anterior, middle, and posterior areas were examined. In dentulous group, the distance between the canal and apex of the first and second molars were measured. Canal-to-alveolar crest distance and lower mandibular border was measured in three different points for both groups. Finally, the upper-lower positions of canals were determined. Results In both groups, most visibility occurred in 1/3 of posterior and the least visibility was detected in 1/3 of anterior, with the intermediate being the most visible part (Type 2). There was no significant difference between the left and right sides in all cases. In dentulous group, no correlation was found between the visibility, age, and gender (p> 0.05); however, canal position was related to gender (p= 0.03 and p= 0.04 in right and left sides, respectively). High position was more frequent in females and intermediate position was more common in males. In edentulous group, no correlation was found between age, gender, and canal position (p> 0.05). Conclusion The most visibility of mandibular canal was in its third posterior and the least was in its third anterior part. Although the middle position of canal was more frequently visible than the high position in this study, it does not refute the possibility of damaging the mandibular canal in critical surgeries. PMID:27284556

  10. Cephalometrically assessing the validity of superior, middle and inferior tragus points on ala-tragus line while establishing the occlusal plane in edentulous patient

    PubMed Central

    Thombare, Ram

    2013-01-01

    PURPOSE The purpose of this study was to decide the most appropriate point on tragus to be used as a reference point at time of marking ala tragus line while establishing occlusal plane. MATERIALS AND METHODS The data was collected in two groups of subjects: 1) Dentulous 2) Edentulous group having sample size of 30 for each group with equal gender distribution (15 males, 15 females each). Downs analysis was used for base value. Lateral cephalographs were taken for all selected subjects. Three points were marked on tragus as Superior (S), Middle (M), and Inferior (I) and were joined with ala (A) of the nose to form ala-tragus lines. The angle formed by each line (SA plane, MA plane, IA plane) with Frankfort Horizontal (FH) plane was measured by using custom made device and modified protractor in all dentulous and edentulous subjects. Also, in dentulous subjects angle between Frankfort Horizontal plane and natural occlusal plane was measured. The measurements obtained were subjected to the following statistical tests; descriptive analysis, Student's unpaired t-test and Pearson's correlation coefficient. RESULTS The results demonstrated, the mean angle COO (cant of occlusal plane) as 9.76°, inferior point on tragus had given the mean angular value of IFH [Angle between IA plane (plane formed by joining inferior point-I on tragus and ala of nose- A) and FH plane) as 10.40° and 10.56° in dentulous and edentulous subjects respectively which was the closest value to the angle COO and was comparable with the values of angle COO value in Downs analysis. Angulations of ala-tragus line marked from inferior point with occlusal plane in dentulous subject had given the smallest value 2.46° which showed that this ala-tragus line was nearly parallel to occlusal plane. CONCLUSION The inferior point marked on tragus is the most appropriate point for marking ala-tragus line. PMID:23508068

  11. A fixed-jaw method to protect critical organs during intensity-modulated radiotherapy

    SciTech Connect

    Chen, Jiayun; Chen, Xinyuan; Huang, Manni; Dai, Jianrong

    2014-01-01

    Intensity-modulated radiotherapy (IMRT) plays an important role in cancer radiotherapy. For some patients being treated with IMRT, the extremely low tolerances of critical organs (such as lens, ovaries, and testicles) cannot be met during treatment planning. The aim of this article is to introduce a new planning method to overcome that problem. In current planning practice, jaw positions are automatically set to cover all target volumes by the planning system (e.g., Pinnacle{sup 3} system). Because of such settings, critical organs may be fully blocked by the multileaf collimator (MLC), but they still sit in the field that is shaped by collimator jaws. These critical organs receive doses from the transmission and leakage of MLC leaves. We manually fixed jaw positions to block them to further reduce such doses. This method has been used for different treatment sites in our clinic, and it was thoroughly evaluated in patients with radical hysterectomy plus ovarian transposition after surgery. For each patient, 2 treatment plans were designed with the same optimization parameters: the original plan with automatically chosen jaw positions (called O-plan) and the plan with fixed-jaw positions (named F-plan). In the F-plan, the jaws were manually fixed to block the ovaries. For target coverage, the mean conformity index (CI) of the F-plan (1.28 ± 0.02) was remarkably lower than that of the O-plan (1.53 ± 0.09) (p < 0.05). The F-plan and the O-plan performed similarly in target dose homogeneity. Meanwhile, for the critical organ sparing, the mean dose of both ovaries were much lower in the F-plan than that in the O-plan (p < 0.05). The V{sub 20}, V{sub 30}, and V{sub 40} of bladder were also lower in the F-plan (93.57 ± 1.98, 73.99 ± 5.76, and 42.33 ± 3.7, respectively) than those in the O-plan (97.98 ± 1.11, 85.07 ± 4.04, and 49.71 ± 3.63, respectively) (p < 0.05). The maximum dose to the spinal cord planning organ at risk (OAR) volume (PRV) in the O-plan (3940

  12. Clinical assessment of the jaw-tracking function in IMRT for a brain tumor

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Young; Kim, Shin-Wook; Choe, Bo-Young; Suh, Tae-Suk; Park, Sung-Kwang; Jo, Sun-Mi; Oh, Won-Yong; Shin, Jung-Wook; Cho, Gyu-Seok; Nam, Sang-Hee; Chung, Jin-Beom; Kim, Jung-Ki; Lee, Young-Kyu

    2015-01-01

    Intensity-modulated radiotherapy (IMRT) improves dose conformity and saves critical organs. IMRT is widely used in cases of head and neck, prostate, and brain cancer due to the close location of the targets to critical structures. However, because IMRT has a larger amount of radiation exposure than 3 dimensional-conformal radiation therapy (3D-CRT), it has disadvantages such as increases in the low dose irradiation to normal tissues and in the accumulated dose for the whole volume due to leakage and transmission of the multi-leaf collimator (MLC). The increased accumulated dose and the larger low dose may increase the occurrence of secondary malignant neoplasms. For these reasons, the jaw-tracking function of the TrueBeam (Varian Medical Systems, Palo Alto, CA) was developed to reduce the leakage and the transmission dose of the MLC with linear accelerators. However, the change in the superficial dose has not been verified with a quantitative analysis of the dose reduction in a brain tumor. Therefore, in the present study, we intended to verify the clinical possibility of utilizing the jaw-tracking function for a brain tumor by comparing treatment plans and superficial doses. To accomplish this, we made three types of original treatment plans using Eclipse11 (Varian Medical Systems, Palo Alto, CA): 1) farther than 2 cm from the organs at risk (OAR); 2) within 2 cm of the OAR; and 3) intersecting with the OAR. Jaw-tracking treatment plans were also made with copies of the original treatment plan using Smart LMC Version 11.0.31 (Varian Medical Systems, Palo Alto, CA). A comparison between the original treatment plans and jaw-tracking treatment plans was performed using the difference of the mean dose and maximum dose to the OARs in cumulative Dose Volume Histogram (DVH). In addition, the dependencies of the effects of transmission and the scattering doses according to jaw motion were assessed through the difference in the surface doses. In the DVH comparison, a

  13. Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation.

    PubMed

    Naumovich, S S; Naumovich, S A; Goncharenko, V G

    2015-01-01

    The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks.

  14. Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation

    PubMed Central

    Goncharenko, V G

    2015-01-01

    The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks. PMID:25564886

  15. Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation.

    PubMed

    Naumovich, S S; Naumovich, S A; Goncharenko, V G

    2015-01-01

    The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks. PMID:25564886

  16. Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

    PubMed Central

    2011-01-01

    Purpose This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). Materials and Methods This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. Results The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. Conclusion CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement. PMID:21977476

  17. The effect of food consistency upon jaw movement in the macaque: a cineradiographic study.

    PubMed

    Thexton, A; Hiiemae, K M

    1997-01-01

    Variation in the form of masticatory cycles in individuals is often assumed to be limited. The contrary hypothesis, that jaw cycles vary widely but systematically with food consistency, was tested in macaques fed similarsized pieces of monkey chow, apple, and banana. With the animals under general anesthesia, radiopaque markers were inserted into the jaw, tongue, and hyoid. Oral movements were recorded by cineradiography at 100 frames/sec in lateral projection synchronously with frontal view cinephotography (50 frames/sec). The films were examined for the events that subdivide each jaw movement cycle into its constituent phases (fast closing, slow closing, intercuspal, slow or early opening, final opening). The frame numbers at which these events occurred were used to define phase durations. The numbers of cycles preceding a swallow increased with the hardness of the ingested food item. Regardless of the test food, every feeding sequence (initial ingestion to final clearance of mouth) contained multiple swallows, each of which defined the end of a sub-sequences when the animals were feeding on chow, the sub-sequences were initially long (20 cycles or more), but when they were feeding on banana, the sub-sequences were short (10 cycles or fewer). Although the form of individual cycles (defined by phase durations) was often unrelated to that of neighboring cycles, the general cycle characteristics in a sub-sequence typified a particular food. Chow feeding cycles were characterized by slow-closing (SC) phases of long duration with slow-opening (SO) phases of short duration; the characteristics of banana feeding cycles were the reverse. SC duration correlated directly and SO duration correlated inversely with food hardness (p < 0.001). The evidence supports the view that the centrally generated pattern of movement is highly dependent upon intra-oral sensory feedback.

  18. Frowning and Jaw Clenching Muscle Activity Reflects the Perception of Effort During Incremental Workload Cycling

    PubMed Central

    Huang, Ding-Hau; Chou, Shih-Wei; Chen, Yi-Lang; Chiou, Wen-Ko

    2014-01-01

    The present study aimed to investigate whether facial electromyography (EMG) recordings reflect the perception of effort and primary active lower limb muscle activity during incremental workload cycling. The effects of exercise intensity on EMG activity of the corrugator supercilii (CS), masseter and vastus lateralis (VL) muscles, heart rate (HR) and the rating of perceived exertion (RPE) were investigated, and the correlations among these parameters were determined. Eighteen males and 15 females performed continuous incremental workload cycling exercise until exhaustion. CS, masseter and VL muscle activities were continuously recorded using EMG during exercise. HR was also continuously monitored during the test. During the final 30 s of each stage of cycle ergometer exercise, participants were asked to report their feeling of exertion on the adult OMNI-Cycle RPE. HR and EMG activity of the facial muscles and the primary active lower limb muscle were strongly correlated with RPE; they increased with power output. Furthermore, facial muscle activity increased significantly during high-intensity exercise. Masseter muscle activity was strongly and positively correlated with HR, RPE and VL activity. The present investigation supports the view that facial EMG activity reflects the perception of effort. The jaw clenching facial expression can be considered an important factor for improving the reporting of perceived effort during high-intensity exercise in males and females. Key points Frowning and jaw clenching muscle activity reflects the perception of effort during incremental workload cycling. EMG activity of the masseter muscle was strongly and positively correlated with RPE, HR and lower limb EMG activity during incremental workload cycling. The jaw clenching facial expression can be considered an important factor for estimating the intensity of effort. PMID:25435786

  19. Bisphosphonate-related osteonecrosis of the jaws: a potential alternative to drug holidays.

    PubMed

    Damm, Douglas D; Jones, David M

    2013-08-01

    In 2011, the American Dental Association Council on Scientific Affairs released an update by their expert panel on managing the care of patients receiving antiresorptive therapy for the prevention and treatment of osteoporosis. In this report, the panel found no study results that confirmed the effectiveness of drug holidays to prevent antiresorptive agent-induced osteonecrosis of the jaws without increasing the risks of low bone mass. The purpose of this article is to provide suggestions for a pattern of patient care for individuals who desire or require an invasive surgical procedure of the jaws, but who also have a skeleton that is at risk for osteoporotic fracture. The authors reviewed pertinent literature related to basic bone histology, the pharmacokinetics of the aminobisphosphonates (nBP), diagnostic criteria for osteopenia/osteoporosis, and clinical applications of the antiresorptive agents. The skeletal system demonstrates a mixture of resting surfaces (osteocytes, 85%), resorbing surfaces (osteoclasts, 2%), and forming surfaces (osteoblasts, 10%-12%). Deposition of nBP is not uniform, and is highly concentrated in areas of bone remodeling. A full understanding of bone remodeling and the pharmacokinetics of nBP allow for the modification of the antiresorptive therapy and the timing of the oral surgical procedure in a manner that minimizes the prevalence of osteonecrosis while at the same time continuing to protect the patient's skeleton from osteoporotic fracture. The lack of support for drug holidays by the ADA's expert panel is strongly consistent with the science behind bone remodeling and nBP pharmacokinetics. In spite of this, creative interdisciplinary patient care has the potential to dramatically reduce the prevalence of bisphosphonate-related osteonecrosis (BRON), while at the same time continuing to protect the skeleton of the osteoporotic patient. Creative interdisciplinary patient care may prove to be an effective intervention to reduce the

  20. Sagittal jaw position in relation to body posture in adult humans – a rasterstereographic study

    PubMed Central

    Lippold, Carsten; Danesh, Gholamreza; Schilgen, Markus; Drerup, Burkhard; Hackenberg, Lars

    2006-01-01

    Background The correlations between the sagittal jaw position and the cranio – cervical inclination are described in literature. Only few studies focus on the sagittal jaw position and the body posture using valid and objective orthopaedic examination methods. The aim of this study was to test the hypothesis that patients with malocclusions reveal significant differences in body posture compared to those without (upper thoracic inclination, kyphotic angle, lordotic angle and lower lumbar inclination). Methods Eighty-four healthy adult patients (with a mean age = 25.6 years and ranging from 16.1 to 55.8 years) were examined with informed consent. The orthodontic examination horizontal overjet (distance between upper and lower incisors) was determined by using an orthodontic digital sliding calliper. The subjects were subdivided in respect of the overjet with the following results: 18 revealed a normal overjet (Class I), 38 had an increased overjet (Class II) and 28 had an reversed overjet (Class III). Rasterstereography was used to carry out a three – dimensional back shape analysis. This method is based on photogrammetry. A three-dimensional shape was produced by analysing the distortion of parallel horizontal white light lines projected on the patient's back, followed by mathematical modelling. On the basis of the sagittal profile the upper thoracic inclination, the thoracic angle, the lordotic angle and the pelvic inclination were determined with a reported accuracy of 2.8° and the correlations to the sagittal jaw position were calculated by means of ANOVA, Scheffé and Kruskal-Wallis procedures. Results Between the different overjet groups, no statistically significant differences or correlations regarding the analysed back shape parameters could be obtained. However, comparing males and females there were statistically significant differences in view of the parameters 'lordotic angle' and 'pelvic inclination'. Conclusion No correlations between overjet and

  1. Rehabilitation of an edentulous cleft lip and palate patient with a soft palate defect using a bar-retained, implant-supported speech-aid prosthesis: a clinical report.

    PubMed

    Hakan Tuna, S; Pekkan, Gurel; Buyukgural, Bulent

    2009-01-01

    Prosthetic rehabilitation of an edentulous cleft lip and palate patient with a combined hard and soft palate defect is a great challenge, due to the lack of retention of the obturator prosthesis as a result of its weight and the inability to obtain a border seal. Dental implants improve the retention, stability, and occlusal function of prostheses when used in carefully selected cleft lip and palate cases. This clinical report presents an edentulous unilateral cleft lip and palate patient who has hard and soft palate defects and an atrophied maxilla, treated with an implant-supported speech-aid prosthesis. PMID:19115799

  2. Development of Flight Slit-Jaw Optics for Chromospheric Lyman-Alpha SpectroPolarimeter

    NASA Technical Reports Server (NTRS)

    Kubo, Masahito; Suematsu, Yoshinori; Kano, Ryohei; Bando, Takamasa; Hara, Hirohisa; Narukage, Noriyuki; Katsukawa, Yukio; Ishikawa, Ryoko; Ishikawa, Shin-nosuke; Kobiki, Toshihiko; Tsuneta, Saku; Kobayashi, Ken; Winebarger, Amy; Takeyama, Norihide; Kanai, Yoshikazu; Sakakibara, Yoshiko

    2015-01-01

    In sounding rocket experiment CLASP, I have placed a slit a mirror-finished around the focal point of the telescope. The light reflected by the mirror surface surrounding the slit is then imaged in Slit-jaw optical system, to obtain the a-ray Lyman secondary image. This image, not only to use the real-time image in rocket flight rocket oriented direction selection, and also used as a scientific data showing the spatial structure of the Lyman alpha emission line intensity distribution and solar chromosphere around the observation area of the polarimetric spectroscope. Slit-jaw optical system is a two off-axis mirror unit part including a parabolic mirror and folding mirror, Lyman alpha transmission filter, the optical system magnification 1x consisting camera. The camera is supplied from the United States, and the other was carried out fabrication and testing in all the Japanese side. Slit-jaw optical system, it is difficult to access the structure, it is necessary to install the low place clearance. Therefore, influence the optical performance, the fine adjustment is necessary optical elements are collectively in the form of the mirror unit. On the other hand, due to the alignment of the solar sensor in the US launch site, must be removed once the Lyman alpha transmission filter holder including a filter has a different part from the mirror unit. In order to make the structure simple, stray light measures Aru to concentrate around Lyman alpha transmission filter. To overcome the difficulties of performing optical alignment in Lyman alpha wavelength absorbed by the atmosphere, it was planned 'following four steps in order to reduce standing time alignment me. 1. is measured in advance refractive index at Lyman alpha wavelength of Lyman alpha transmission filter (121.567nm), to prepare a visible light Firuwo having the same optical path length in the visible light (630nm).2. The mirror structure CLASP before mounting unit standing, dummy slit and camera standing

  3. 3D computer data capture and imaging applied to the face and jaws.

    PubMed

    Spencer, R; Hathaway, R; Speculand, B

    1996-02-01

    There have been few attempts in the past at 3D computer modelling of facial deformity because of the difficulties with generating accurate three-dimensional data and subsequent image regeneration and manipulation. We report the application of computer aided engineering techniques to the study of jaw deformity. The construction of a 3D image of the mandible using a Ferranti co-ordinate measuring machine for data capture and the 'DUCT5' surface modelling programme for image regeneration is described. The potential application of this work will be discussed. PMID:8645664

  4. Proprioceptive ability at the lips and jaw measured using the same psychophysical discrimination task.

    PubMed

    Frayne, Ellie; Coulson, Susan; Adams, Roger; Croxson, Glen; Waddington, Gordon

    2016-06-01

    In the human face, the muscles and joints that generate movement have different properties. Whereas the jaw is a conventional condyle joint, the facial musculature has neither distinct origin nor insertion points, and the muscles do not contain muscle spindle proprioceptors. This current study aims to compare the proprioceptive ability at the orofacial muscles with that of the temporomandibular joint (TMJ) in 21 neuro-typical people aged between 18 and 65 years. A novel psychophysical task was devised for use with both structures that involved a fixed 30.5 mm start separation followed by closure onto stimuli of 5, 6, 7, 8 mm diameter. The mean proprioceptive score when using the lips was 0.84 compared to 0.79 at the jaw (p < 0.001), and response error was lower by 0.1 mm. The greater accuracy in discrimination of lip movement is significant because, unlike the muscles controlling the TMJ, the orbicularis oris muscle controlling the lips inserts on to connective tissue and other muscle, and contains no muscle spindles, implying a different more effective, proprioceptive mechanism. Additionally, unlike the lack of correlation previously observed between joints in the upper and lower limbs, at the face the scores from performing the task with the two different structures were significantly correlated (r = 0.5, p = 0.018). These data extend the understanding of proprioception being correlated for the same left and right joints and correlated within the same structure (e.g. ankle dorsiflexion and inversion), to include use-dependant proprioception, with performance in different structures being correlated through extended coordinated use. At the lips and jaw, it is likely that this arises from extensive coordinated use. This informs clinical assessment and suggests a potential for coordinated post-injury training of the lips and jaw, as well as having the potential to predict premorbid function via measurement of the uninjured structure, when monitoring

  5. Proprioceptive ability at the lips and jaw measured using the same psychophysical discrimination task.

    PubMed

    Frayne, Ellie; Coulson, Susan; Adams, Roger; Croxson, Glen; Waddington, Gordon

    2016-06-01

    In the human face, the muscles and joints that generate movement have different properties. Whereas the jaw is a conventional condyle joint, the facial musculature has neither distinct origin nor insertion points, and the muscles do not contain muscle spindle proprioceptors. This current study aims to compare the proprioceptive ability at the orofacial muscles with that of the temporomandibular joint (TMJ) in 21 neuro-typical people aged between 18 and 65 years. A novel psychophysical task was devised for use with both structures that involved a fixed 30.5 mm start separation followed by closure onto stimuli of 5, 6, 7, 8 mm diameter. The mean proprioceptive score when using the lips was 0.84 compared to 0.79 at the jaw (p < 0.001), and response error was lower by 0.1 mm. The greater accuracy in discrimination of lip movement is significant because, unlike the muscles controlling the TMJ, the orbicularis oris muscle controlling the lips inserts on to connective tissue and other muscle, and contains no muscle spindles, implying a different more effective, proprioceptive mechanism. Additionally, unlike the lack of correlation previously observed between joints in the upper and lower limbs, at the face the scores from performing the task with the two different structures were significantly correlated (r = 0.5, p = 0.018). These data extend the understanding of proprioception being correlated for the same left and right joints and correlated within the same structure (e.g. ankle dorsiflexion and inversion), to include use-dependant proprioception, with performance in different structures being correlated through extended coordinated use. At the lips and jaw, it is likely that this arises from extensive coordinated use. This informs clinical assessment and suggests a potential for coordinated post-injury training of the lips and jaw, as well as having the potential to predict premorbid function via measurement of the uninjured structure, when monitoring

  6. Development of Flight Slit-Jaw Optics for Chromospheric Lyman-Alpha SpectroPolarimeter

    NASA Technical Reports Server (NTRS)

    Kubo, Masahito; Suematsu, Yoshinori; Kano, Ryohei; Bando, Takamasa; Hara, Hirohisa; Narukage, Noriyuki; Katsukawa, Yukio; Ishikawa, Ryoko; Ishikawa, Shin-nosuke; Kobiki, Toshihiko; Tsuneta, Saku; Kobayashi, Ken; Winebarger, Amy; Takeyama, Norihide; Kanai, Yoshikazu; Sakakibara, Yoshiko

    2015-01-01

    In sounding rocket experiment CLASP, I have placed a slit a mirror-finished around the focal point of the telescope. The light reflected by the mirror surface surrounding the slit is then imaged in Slit-jaw optical system, to obtain the alpha-ray Lyman secondary image. This image, not only to use the real-time image in rocket flight rocket oriented direction selection, and also used as a scientific data showing the spatial structure of the Lyman alpha emission line intensity distribution and solar chromosphere around the observation area of the polarimetric spectroscope. Slit-jaw optical system is a two off-axis mirror unit part including a parabolic mirror and folding mirror, Lyman alpha transmission filter, the optical system magnification 1x consisting camera. The camera is supplied from the United States, and the other was carried out fabrication and testing in all the Japanese side. Slit-jaw optical system, it is difficult to access the structure, it is necessary to install the low place clearance. Therefore, influence the optical performance, the fine adjustment is necessary optical elements are collectively in the form of the mirror unit. On the other hand, due to the alignment of the solar sensor in the US launch site, must be removed once the Lyman alpha transmission filter holder including a filter has a different part from the mirror unit. In order to make the structure simple, stray light measures Aru to concentrate around Lyman alpha transmission filter. To overcome the difficulties of performing optical alignment in Lyman alpha wavelength absorbed by the atmosphere, it was planned following four steps in order to reduce standing time alignment me. 1: is measured in advance refractive index at Lyman alpha wavelength of Lyman alpha transmission filter (121.567nm), to prepare a visible light Firuwo having the same optical path length in the visible light (630nm). 2: The mirror structure CLASP before mounting unit standing, dummy slit and camera standing

  7. Amoxicillin concentrations in serum, jaw cyst, and jawbone following a single oral administration.

    PubMed

    Akimoto, Y; Kaneko, K; Tamura, T

    1982-05-01

    Forty-four patient who underwent enucleation of jaw cysts were administered amoxicillin preoperatively. Specimens of venous blood (44), walls and fluids from periodontal (31) and dentigerous (13) cysts, and jawbone (26) were obtained during the operation and assayed for amoxicillin content. Measurable concentrations were found in all specimens. The levels were higher in periodontal cysts than in dentigerous cysts, and higher in maxillary bone than in mandibular bone. Since amoxicillin can easily and rapidly pass through the epithelial lining according to the change in concentration, the penetration by amoxicillin of blood/cyst wall/cyst fluid probably depends on simple diffusion.

  8. [Peculiarities of face regional hemodynamics in treatment of acute purulent jaw odontogenic periostitis].

    PubMed

    Fedotov, S N; Sukhanov, A E; Konkina, M A; Iakovlev, V E

    2010-01-01

    53 patients were under observation with acute purulent jaw odontogenic periostitis. In 27 out of them after operation as drainage material strips of napkin were used, containing as the active components metronidazol, dimexide and sodium alginate. Curative process efficacy evaluation was done according to the data of hemodynamic study (determination of the artery's diameter, maximal systolic speed and index of circulatory resistance) of the magistral face arteries. It was established that in the group of patients with rational treatment blood circulation in face arterial vessels was restored most actively than in the control group with the use of traditional treatment scheme.

  9. Periodontal Disease, Dental Implants, Extractions and Medications Related to Osteonecrosis of the Jaws.

    PubMed

    Shah, Neha P; Katsarelis, Helen; Pazianas, Michael; Dhariwal, Daljit K

    2015-11-01

    Patients taking bisphosphonates and other anti-resorptive drugs are likely to attend general dental practice. The term 'bisphosphonate'is often immediately associated with osteonecrosis of the jaws (ONJ). Risk assessment and subsequent management of these patients should be carried out taking into account all the risk factors associated with ONJ. The introduction of newer drugs, also shown to be associated with ONJ, demands increased awareness of general dental practitioners about these medications. CPD/CLINICAL RELEVANCE: This paper provides an update on medication-related ONJ and considers the effects of anti-resorptive drugs on the management of patients needing exodontia, treatment for periodontal disease and dental implant placement.

  10. Variance Components: Partialled vs. Common.

    ERIC Educational Resources Information Center

    Curtis, Ervin W.

    1985-01-01

    A new approach to partialling components is used. Like conventional partialling, this approach orthogonalizes variables by partitioning the scores or observations. Unlike conventional partialling, it yields a common component and two unique components. (Author/GDC)

  11. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-17

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  12. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  13. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    2001-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  14. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-24

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  15. Oxygen partial pressure sensor

    DOEpatents

    Dees, D.W.

    1994-09-06

    A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured. 1 fig.

  16. Oxygen partial pressure sensor

    DOEpatents

    Dees, Dennis W.

    1994-01-01

    A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured.

  17. Dynamics of partial control.

    PubMed

    Sabuco, Juan; Sanjuán, Miguel A F; Yorke, James A

    2012-12-01

    Safe sets are a basic ingredient in the strategy of partial control of chaotic systems. Recently we have found an algorithm, the sculpting algorithm, which allows us to construct them, when they exist. Here we define another type of set, an asymptotic safe set, to which trajectories are attracted asymptotically when the partial control strategy is applied. We apply all these ideas to a specific example of a Duffing oscillator showing the geometry of these sets in phase space. The software for creating all the figures appearing in this paper is available as supplementary material. PMID:23278093

  18. Denosumab Related Osteonecrosis of the Jaw with Spontaneous Necrosis of the Soft Palate: Report of a Life Threatening Case.

    PubMed

    Qaisi, Mohammed; Hargett, Jamie; Loeb, Matthew; Brown, Jeffrey; Caloss, Ronald

    2016-01-01

    Bisphosphonates have been used for years in the treatment of patients with distant bony metastasis and in the prevention of osteoporosis. One of main side effects of these medications is the development of bisphosphonate related osteonecrosis of the jaw (BRONJ) in a small subset of patients. A new class of medications with a shorter half-life, known as receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors, was introduced with the hopes of avoiding this side effect. However, reports of osteonecrosis of the jaw after the use of RANKL inhibitors have also been documented. We report on a patient who developed a life threatening osteonecrosis of the jaw with sepsis shortly after switching from a bisphosphonate to a RANKL inhibitor for osteoporosis treatment. This patient developed several soft tissue defects including spontaneous necrosis of the soft palate. To our knowledge this is the first time this presentation has been described. PMID:27648313

  19. Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion

    PubMed Central

    Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Wilga, Cheryl D.; Ramsay, Jason B.; Schlader, Robert; Didier, Dominique A.

    2013-01-01

    New CT scans of the spiral-tooth fossil, Helicoprion, resolve a longstanding mystery concerning the form and phylogeny of this ancient cartilaginous fish. We present the first three-dimensional images that show the tooth whorl occupying the entire mandibular arch, and which is supported along the midline of the lower jaw. Several characters of the upper jaw show that it articulated with the neurocranium in two places and that the hyomandibula was not part of the jaw suspension. These features identify Helicoprion as a member of the stem holocephalan group Euchondrocephali. Our reconstruction illustrates novel adaptations, such as lateral cartilage to buttress the tooth whorl, which accommodated the unusual trait of continuous addition and retention of teeth in a predatory chondrichthyan. Helicoprion exemplifies the climax of stem holocephalan diversification and body size in Late Palaeozoic seas, a role dominated today by sharks and rays. PMID:23445952

  20. Denosumab Related Osteonecrosis of the Jaw with Spontaneous Necrosis of the Soft Palate: Report of a Life Threatening Case

    PubMed Central

    Hargett, Jamie; Brown, Jeffrey; Caloss, Ronald

    2016-01-01

    Bisphosphonates have been used for years in the treatment of patients with distant bony metastasis and in the prevention of osteoporosis. One of main side effects of these medications is the development of bisphosphonate related osteonecrosis of the jaw (BRONJ) in a small subset of patients. A new class of medications with a shorter half-life, known as receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors, was introduced with the hopes of avoiding this side effect. However, reports of osteonecrosis of the jaw after the use of RANKL inhibitors have also been documented. We report on a patient who developed a life threatening osteonecrosis of the jaw with sepsis shortly after switching from a bisphosphonate to a RANKL inhibitor for osteoporosis treatment. This patient developed several soft tissue defects including spontaneous necrosis of the soft palate. To our knowledge this is the first time this presentation has been described.

  1. Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion.

    PubMed

    Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Wilga, Cheryl D; Ramsay, Jason B; Schlader, Robert; Didier, Dominique A

    2013-04-23

    New CT scans of the spiral-tooth fossil, Helicoprion, resolve a longstanding mystery concerning the form and phylogeny of this ancient cartilaginous fish. We present the first three-dimensional images that show the tooth whorl occupying the entire mandibular arch, and which is supported along the midline of the lower jaw. Several characters of the upper jaw show that it articulated with the neurocranium in two places and that the hyomandibula was not part of the jaw suspension. These features identify Helicoprion as a member of the stem holocephalan group Euchondrocephali. Our reconstruction illustrates novel adaptations, such as lateral cartilage to buttress the tooth whorl, which accommodated the unusual trait of continuous addition and retention of teeth in a predatory chondrichthyan. Helicoprion exemplifies the climax of stem holocephalan diversification and body size in Late Palaeozoic seas, a role dominated today by sharks and rays.

  2. Denosumab Related Osteonecrosis of the Jaw with Spontaneous Necrosis of the Soft Palate: Report of a Life Threatening Case

    PubMed Central

    Hargett, Jamie; Brown, Jeffrey; Caloss, Ronald

    2016-01-01

    Bisphosphonates have been used for years in the treatment of patients with distant bony metastasis and in the prevention of osteoporosis. One of main side effects of these medications is the development of bisphosphonate related osteonecrosis of the jaw (BRONJ) in a small subset of patients. A new class of medications with a shorter half-life, known as receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors, was introduced with the hopes of avoiding this side effect. However, reports of osteonecrosis of the jaw after the use of RANKL inhibitors have also been documented. We report on a patient who developed a life threatening osteonecrosis of the jaw with sepsis shortly after switching from a bisphosphonate to a RANKL inhibitor for osteoporosis treatment. This patient developed several soft tissue defects including spontaneous necrosis of the soft palate. To our knowledge this is the first time this presentation has been described. PMID:27648313

  3. Concept, diagnosis and classification of bisphosphonate-associated osteonecrosis of the jaws. A review of the literature

    PubMed Central

    Bagan, Jose V.

    2016-01-01

    Background Bisphosphonates (BPs) and other antiresorptive agents such as denosumab are widely prescribed for the treatment of osteoporosis and are also used in patients with multiple myeloma and metastatic breast or prostate cancer for avoiding bone reabsorption and fractures that result in increased morbidity-mortality among such individuals. Material and Methods We made a bibliographic search to analyze the concept, diagnosis and the different classifications for bisphosphonate-associated osteonecrosis of the jaws. Results Osteonecrosis of the jaws (ONJ) is an important complication of exposure to BPs or other antiresorptive agents, and although its prevalence is low, it can pose management problems. The definition, diagnosis and classification of osteonecrosis have evolved since Marx reported the first cases in 2003. Conclusions The present study offers a literature review and update on the existing diagnostic methods and classification of the disorder, with a view to facilitating earlier and more effective treatment. Key words:Osteonecrosis, jaws, bisphosphonates. PMID:26827066

  4. Fit accuracy of metal partial removable dental prosthesis frameworks fabricated by traditional or light curing modeling material technique: An in vitro study

    PubMed Central

    Anan, Mohammad Tarek M.; Al-Saadi, Mohannad H.

    2015-01-01

    Objective The aim of this study was to compare the fit accuracies of metal partial removable dental prosthesis (PRDP) frameworks fabricated by the traditional technique (TT) or the light-curing modeling material technique (LCMT). Materials and methods A metal model of a Kennedy class III modification 1 mandibular dental arch with two edentulous spaces of different spans, short and long, was used for the study. Thirty identical working casts were used to produce 15 PRDP frameworks each by TT and by LCMT. Every framework was transferred to a metal master cast to measure the gap between the metal base of the framework and the crest of the alveolar ridge of the cast. Gaps were measured at three points on each side by a USB digital intraoral camera at ×16.5 magnification. Images were transferred to a graphics editing program. A single examiner performed all measurements. The two-tailed t-test was performed at the 5% significance level. Results The mean gap value was significantly smaller in the LCMT group compared to the TT group. The mean value of the short edentulous span was significantly smaller than that of the long edentulous span in the LCMT group, whereas the opposite result was obtained in the TT group. Conclusion Within the limitations of this study, it can be concluded that the fit of the LCMT-fabricated frameworks was better than the fit of the TT-fabricated frameworks. The framework fit can differ according to the span of the edentate ridge and the fabrication technique for the metal framework. PMID:26236129

  5. Partial hue-matching.

    PubMed

    Logvinenko, Alexander D; Beattie, Lesley L

    2011-01-01

    It is widely believed that color can be decomposed into a small number of component colors. Particularly, each hue can be described as a combination of a restricted set of component hues. Methods, such as color naming and hue scaling, aim at describing color in terms of the relative amount of the component hues. However, there is no consensus on the nomenclature of component hues. Moreover, the very notion of hue (not to mention component hue) is usually defined verbally rather than perceptually. In this paper, we make an attempt to operationalize such a fundamental attribute of color as hue without the use of verbal terms. Specifically, we put forth a new method--partial hue-matching--that is based on judgments of whether two colors have some hue in common. It allows a set of component hues to be established objectively, without resorting to verbal definitions. Specifically, the largest sets of color stimuli, all of which partially match each other (referred to as chromaticity classes), can be derived from the observer's partial hue-matches. A chromaticity class proves to consist of all color stimuli that contain a particular component hue. Thus, the chromaticity classes fully define the set of component hues. Using samples of Munsell papers, a few experiments on partial hue-matching were carried out with twelve inexperienced normal trichromatic observers. The results reinforce the classical notion of four component hues (yellow, blue, red, and green). Black and white (but not gray) were also found to be component colors. PMID:21742961

  6. Partial knee replacement

    MedlinePlus

    ... You will need to understand what surgery and recovery will be like. Partial knee arthroplasty may be a good choice if you have arthritis in only one side or part of the knee and: You are older, thin, and not very active. You do not ...

  7. A piezoelectric motor-based microactuator-generated distractor for continuous jaw bone distraction.

    PubMed

    Park, Jong-Tae; Lee, Jae-Gi; Kim, Soo-Yeon; Kim, Gyu-Hag; Hu, Kyung-Seok; Cha, Jung-Yul; Kim, Hyung Jun; Kim, Hee-Jin

    2011-07-01

    Distraction osteogenesis is widely applied to correct oral and maxillofacial deformities, and intermittent distraction protocols have been used in various clinical applications. There are many challenges for continuous distraction of the jaw bone such as when using hydraulic motors and motor-driven plates. The size of the motor is critical to the ability to miniaturize the complete distractor system, and the importance of size makes it difficult to extrapolate the results of animal models to the clinical situation. This study developed a microactuator-generated distractor (MAGD) for continuous jaw bone distraction. The MAGD system consists of control software based on Microsoft Windows and a Squiggle piezoelectric motor. The system allows various intermittent and continuous distraction protocols to be simply selected using the control software. The maximum force of the laboratory-scale MAGD is 3 N, and the device is ready for adoption in small-animal distraction models such as the rat and mouse. The MAGD needs further refinement before it can be applied to humans, but a fully implanted MAGD system will reduce soft-tissue complications resulting from exposure of the extraoral component. Moreover, the MAGD will support the patient's social activities and require only minimal cooperation from the patient.

  8. Metagenomic investigation of microbes and viruses in patients with jaw osteonecrosis associated with bisphosphonate therapy

    PubMed Central

    Sedghizadeh, Parish P.; Yooseph, Shibu; Fadrosh, Douglas W.; Zeigler-Allen, Lisa; Thiagarajan, Mathangi; Salek, Hamid; Farahnik, Farid; Williamson, Shannon J.

    2013-01-01

    Objective The goal of this preliminary study was to use metagenomic approaches to investigate the taxonomic diversity of microorganisms in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). Study Design Samples of saliva for planktonic microbial analysis and biofilm cultivation were collected from 10 patients (5 with BRONJ and 5 non-BRONJ control subjects) who met all ascertainment criteria. Prophage induction experiments—16S rRNA polymerase chain reaction and 454 pyrosequencing—and epifluorescent microscopy were performed for characterization and enumeration of microbes and viruses. Results Three phyla of microbes—Proteobacteria (70%), Firmicutes (26.9%), and Actinobacteria (1.95%)—dominated all BRONJ samples and accounted for almost 99% of the total data. Viral abundance was ~1 order of magnitude greater than microbial cell abundance and comprised mainly phage viruses. Conclusions Individuals with jaw osteonecrosis harbored different microbial assemblages than nonaffected patients, and in general viral abundance and prophage induction increased with biofilm formation, suggesting that biofilm formation encouraged lysogenic interactions between viruses and microbial hosts and may contribute to pathogenicity. PMID:23159114

  9. Three dimensional digital reconstruction of the jaw adductor musculature of the extinct marsupial giant Diprotodon optatum

    PubMed Central

    2014-01-01

    The morphology and arrangement of the jaw adductor muscles in vertebrates reflects masticatory style and feeding processes, diet and ecology. However, gross muscle anatomy is rarely preserved in fossils and is, therefore, heavily dependent on reconstructions. An undeformed skull of the extinct marsupial, Diprotodon optatum, recovered from Pleistocene sediments at Bacchus Marsh in Victoria, represents the most complete and best preserved specimen of the species offering a unique opportunity to investigate functional anatomy. Computed tomography (CT) scans and digital reconstructions make it possible to visualise internal cranial anatomy and predict location and morphology of soft tissues, including muscles. This study resulted in a 3D digital reconstruction of the jaw adductor musculature of Diprotodon, revealing that the arrangement of muscles is similar to that of kangaroos and that the muscle actions were predominantly vertical. 3D digital muscle reconstructions provide considerable advantages over 2D reconstructions for the visualisation of the spatial arrangement of the individual muscles and the measurement of muscle properties (length, force vectors and volume). Such digital models can further be used to estimate muscle loads and attachment sites for biomechanical analyses. PMID:25165628

  10. Effects of prolonged gum chewing on pain and fatigue in human jaw muscles.

    PubMed

    Farella, M; Bakke, M; Michelotti, A; Martina, R

    2001-04-01

    Gum chewing has been accepted as an adjunct to oral hygiene, as salivary stimulant and vehicle for various agents, as well as for jaw muscle training. The aim of this study was to investigate the effects of prolonged gum chewing on pain, fatigue and pressure tenderness of the masticatory muscles. Fifteen women without temporomandibular disorders (TMD) were requested to perform one of the following chewing tasks in three separate sessions: chewing a very hard gum, chewing a soft gum, and empty-chewing with no bolus. Unilateral chewing of gum or empty chewing was performed for 40 min at a constant rate of 80 cycles/min. In each session, perceived muscle pain and masticatory fatigue were rated on visual analog scales (VAS) before, throughout, and after the chewing task. Pressure pain thresholds (PPTs) of masseter and anterior temporalis muscles were assessed before and immediately after the chewing tasks, and again after 24 h. The VAS scores for pain and fatigue significantly increased only during the hard gum chewing, and after 10 min of recovery VAS scores had decreased again, almost to their baseline values. No significant changes were found for PPTs either after hard or soft gum chewing. The findings indicate that the jaw muscles recover quickly from prolonged chewing activity in subjects without TMD.

  11. Jaw myology and bite force of the monk parakeet (Aves, Psittaciformes).

    PubMed

    Carril, Julieta; Degrange, Federico J; Tambussi, Claudia P

    2015-07-01

    Psittaciform birds exhibit novelties in jaw bone structure and musculature that are associated with strong bite forces. These features include an ossified arcus suborbitalis and the muscles ethmomandibularis and pseudomasseter. We analyse the jaw musculature of the monk parakeet (Myiopsitta monachus) to enable future studies aimed at understanding craniofacial development, morphology, function and evolution. We estimate bite force based on muscle dissections, physiological cross-sectional area and skull biomechanical modelling. We also compare our results with available data for other birds and traced the evolutionary origin of the three novel diagnostic traits. Our results indicate that, in Myiopsitta, (i) the arcus suborbitalis is absent and the orbit is ventrally closed by an elongate processus orbitalis and a short ligamentum suborbitale; (ii) the ethmomandibularis muscle is a conspicuous muscle with two bellies, with its origin on the anterior portion of the septum interorbitale and insertion on the medial aspect of the mandible; (iii) the pseudomasseter muscle consists of some fibers arising from the m. adductor mandibulae externus superficialis, covering the lateral surface of the arcus jugalis and attaches by an aponeurotic sheet on the processus orbitalis; (iv) a well-developed adductor mandibulae complex is present; (v) the bite force estimation relative to body mass is higher than that calculated for other non-psittaciform species; and (vi) character evolution analysis revealed that the absence of the arcus suborbitalis and the presence of the m. pseudomassseter are the ancestral conditions, and mapping is inconclusive about presence of one or two bellies of the m. ethmomandibularis.

  12. Patterning of mammalian heterodont dentition within the upper and lower jaws.

    PubMed

    Yamanaka, Atsushi; Iwai, Haruki; Uemura, Masanori; Goto, Tetsuya

    2015-01-01

    Mammalian heterodont dentition is differentiated into incisors, canines, premolars, and molars in the mesial-distal direction, in both the upper and lower jaws. Although all the lower teeth are rooted in the mandible, the upper incisors are rooted in the premaxilla and the upper canine and the teeth behind it are in the maxilla. The present study uncovers ontogenetic backgrounds to these shared and differing mesiodistal patterns of the upper and lower dentition. To this end, we examined the dentition development of the house shrew, Suncus murinus, instead of the rodent model animals because the dentition of this primitive eutherian species includes all the tooth classes, and no toothless diastema region. In the shrew, the upper incisor-forming region extended over the medial nasal prominence and the mesial part of the maxillary prominence. Consequently, the maxillary and mandibular prominences were in a mirror-image relationship in terms of the mesiodistally differentiated tooth-forming regions and of the complementary gene expression pattern, with Bmp4 in the mesial and Fgf8 in the distal regions. This suggests shared molecular mechanisms regulating tooth class differentiation between the upper and lower jaws. However, the premaxillary bone appeared within the mesenchyme of the medial nasal prominence, but grew distally beyond the former epithelial boundary with the maxillary prominence to form, finally, the incisive (premaxillary-maxillary) suture just mesial to the canine. Therefore, the developmental locations of the upper incisors are not inconsistent with the classical osteological criterion of the upper canine by comparative odontologists.

  13. Combination of Mandibular Constriction and Intraoral Vertical Ramus Osteotomies for a Transverse Jaw Discrepancy

    PubMed Central

    Mitsugi, Masaharu; Hirose, Hisamitsu; Tatemoto, Yukihiro

    2015-01-01

    Background: The aim of the present study was to evaluate the treatment of patients developing a transverse jaw width discrepancy who exhibited class III malocclusion and/or facial asymmetry by a combination of mandibular constriction (MC) and intraoral vertical ramus osteotomies (IVROs). Subjects and methods: In a retrospective study, functional results, postoperative complications, and skeletal stability were analyzed for all the patients who had undergone MC and IVRO, with more than 2 years of follow-up. A mandibular midline osteotomy for constriction with lag screw technique and IVROs was used for MC and setback. Results: Sixteen patients were included in the present study. The average degree of MC was 6.34 mm. Both the occlusal relationship and facial appearance in all patients were significantly improved by the surgical orthodontic treatment, with no harmful clinical symptoms. In addition, our original MC using lag screw technique provided the most reliable results in terms of skeletal stability. Conclusions: This study showed that MC using lag screw technique gives a very stable mandibular width constriction, and the combination of MC and IVROs offers a promising treatment alternative for patients with mandibular prognathism developing a transverse jaw width discrepancy. PMID:26495234

  14. Possible Interbreeding in Late Italian Neanderthals? New Data from the Mezzena Jaw (Monti Lessini, Verona, Italy)

    PubMed Central

    Condemi, Silvana; Mounier, Aurélien; Giunti, Paolo; Lari, Martina; Caramelli, David; Longo, Laura

    2013-01-01

    In this article we examine the mandible of Riparo Mezzena a Middle Paleolithic rockshelter in the Monti Lessini (NE Italy, Verona) found in 1957 in association with Charentian Mousterian lithic assemblages. Mitochondrial DNA analysis performed on this jaw and on other cranial fragments found at the same stratigraphic level has led to the identification of the only genetically typed Neanderthal of the Italian peninsula and has confirmed through direct dating that it belongs to a late Neanderthal. Our aim here is to re-evaluate the taxonomic affinities of the Mezzena mandible in a wide comparative framework using both comparative morphology and geometric morphometrics. The comparative sample includes mid-Pleistocene fossils, Neanderthals and anatomically modern humans. This study of the Mezzena jaw shows that the chin region is similar to that of other late Neanderthals which display a much more modern morphology with an incipient mental trigone (e.g. Spy 1, La Ferrassie, Saint-Césaire). In our view, this change in morphology among late Neanderthals supports the hypothesis of anatomical change of late Neanderthals and the hypothesis of a certain degree of interbreeding with AMHs that, as the dating shows, was already present in the European territory. Our observations on the chin of the Mezzena mandible lead us to support a non abrupt phylogenetic transition for this period in Europe. PMID:23544098

  15. Independent evolution of the specialized pharyngeal jaw apparatus in cichlid and labrid fishes

    PubMed Central

    Mabuchi, Kohji; Miya, Masaki; Azuma, Yoichiro; Nishida, Mutsumi

    2007-01-01

    Background Fishes in the families Cichlidae and Labridae provide good probable examples of vertebrate adaptive radiations. Their spectacular trophic radiations have been widely assumed to be due to structural key innovation in pharyngeal jaw apparatus (PJA), but this idea has never been tested based on a reliable phylogeny. For the first step of evaluating the hypothesis, we investigated the phylogenetic positions of the components of the suborder Labroidei (including Pomacentridae and Embiotocidae in addition to Cichlidae and Labridae) within the Percomorpha, the most diversified (> 15,000 spp) crown clade of teleosts. We examined those based on 78 whole mitochondrial genome sequences (including 12 newly determined sequences) through partitioned Bayesian analyses with concatenated sequences (13,933 bp). Results The resultant phylogenies indicated that the Labridae and the remaining three labroid families have diverged basally within the Percomorpha, and monophyly of the suborder was confidently rejected by statistical tests using Bayes factors. Conclusion The resultant phylogenies indicated that the specified PJA evolved independently at least twice, once in Labridae and once in the common ancestor of the remaining three labroid families (including the Cichlidae). Because the independent evolution of pharyngeal jaws appears to have been followed by trophic radiations, we consider that our result supports, from the aspect of historical repeatability, the idea that the evolution of the specialized PJA provided these lineages with the morphological potential for their spectacular trophic radiations. The present result will provide a new framework for the study of functional morphology and genetic basis of their PJA. PMID:17263894

  16. Cone beam CT evaluation of the presence of anatomic accessory canals in the jaws

    PubMed Central

    Eshak, M; Brooks, S; Abdel-Wahed, N

    2014-01-01

    Objectives: To assess the prevalence, location and anatomical course of accessory canals of the jaws using cone beam CT. Methods: A retrospective analysis of 4200 successive cone beam CT scans, for patients of both genders and ages ranging from 7 to 88 years, was performed. They were exposed at the School of Dentistry, University of Michigan, Ann Arbor, MI. After applying the exclusion criteria (the presence of severe ridge resorption, pre-existing implants, a previously reported history of craniofacial malformations or syndromes, a previous history of trauma or surgery, inadequate image quality and subsequent scans from the same individuals), 4051 scans were ultimately included in this study. Results: Of the 4051 scans (2306 females and 1745 males) that qualified for inclusion in this study, accessory canals were identified in 1737 cases (42.9%; 1004 females and 733 males). 532 scans were in the maxilla (13.1%; 296 females and 236 males) and 1205 in the mandible (29.8%; 708 females and 497 males). Conclusions: A network of accessory canals bringing into communication the inner and outer cortical plates of the jaws was identified. In light of these findings, clinicians should carefully assess for the presence of accessory canals prior to any surgical intervention to decrease the risk for complications. PMID:24670010

  17. Jaw muscles and the skull in mammals: the biomechanics of mastication.

    PubMed

    Herring, S W; Rafferty, K L; Liu, Z J; Marshall, C D

    2001-12-01

    Among non-mammalian vertebrates, rigid skulls with tight sutural junctions are associated with high levels of cranial loading. The rigid skulls of mammals presumably act to resist the stresses of mastication. The pig, Sus scrofa, is a generalized ungulate with a diet rich in resistant foods. This report synthesizes previous work using strain gages bonded to the bones and sutures of the braincase, zygomatic arch, jaw joint, and mandible with new studies on the maxilla. Strains were recorded during unrestrained mastication and/or in anesthetized pigs during muscle stimulation. Bone strains were 100-1000 micro epsilon, except in the braincase, but sutural strains were higher, regardless of region. Strain regimes were specific to different regions, indicating that theoretical treatment of the skull as a unitary structure is probably incorrect. Muscle contraction, especially the masseter, caused strain patterns by four mechanisms: (1) direct loading of muscle attachment areas; (2) a compressive reaction force at the jaw joint; (3) bite force loading on the snout and mandible; and (4) movement causing new points of contact between mandible and cranium. Some expected patterns of loading were not seen. Most notably, strains did not differ for right and left chewing, perhaps because pigs have bilateral occlusion and masseter activity.

  18. Genetic and environmental factors influencing tooth and jaw malformations in rabbits.

    PubMed

    Korn, A K; Brandt, H R; Erhardt, G

    2016-04-01

    Tooth alterations of 281 rabbits from 10 different breeds were evaluated, starting at the age of three weeks until they were fully grown. All rabbits were kept in an outdoor facility, fed with a pelleted diet and had free access to water and hay. The most common finding in 3182 clinical examinations was a gap between the mandibular incisors (38 per cent). Skull X-rays from 4 adult breeding rabbits, 15 offspring with clinical signs of dental disease and 12 clinically healthy siblings were assessed by two different methods using cephalometric distances and anatomical reference lines. Repeatabilities of cephalometric distances were mostly low and no significant associations to tooth health were found. The anatomical reference lines revealed dental findings even in rabbits that were graded as tooth healthy in previous clinical examinations. On the basis of the demonstrated age-dependent development of tooth and jaw malformations a first examination and selection at the age of 12 weeks can be recommended. Also genetic aspects for tooth and jaw malformations were considered. The estimated heritability for brachygnathia superior was 0.254 ± 0.169 for all examinations and 0.105 ± 0.092 comprising the last examination of each rabbit when fully grown.

  19. Statistical observations on jaw cysts in Enugu, Nigeria, 1987-1996.

    PubMed

    Oji, C

    1999-03-01

    Cases of jaw cysts treated at the Department of Oral and Maxillofacial Surgery in the University of Nigeria Teaching Hospital, Enugu during the 10 year period between 1987 and 1996 were studied clinically. A diagnosis of jaw cyst was established in 20 patients during the above period. According to pathological classification by the WHO method, these patients included 10 (50%) with dentigerous cyst, 3 (15%) with radicular cyst, 3 (15%) with odontogenic keratocyst, 3 (15%) with fissural cyst (nasopalatine duct cyst, nasoalveolar cyst, globulomaxillary cyst), 1 (5%) with dermoid cyst. Patients with dentigerous cyst, which was found at relatively high frequency, were further analyzed with regard to age, sex, and anatomical distribution. Among patients with dentigerous cyst, those aged between 21 and 40 years accounted for 60%. Males outnumbered females in a ratio of 1.5:1. Dentigerous cyst occurred most frequently in the region of the mandibular wisdom teeth. The relatively very small number of cases, the need for more research on the subject and the need to educate the general public on oral hygiene are highlighted.

  20. Surgery Combined with LPRF in Denosumab Osteonecrosis of the Jaw: Case Report.

    PubMed

    Maluf, Gustavo; Pinho, Milena Correia de; Cunha, Sandra Ribeiro de Barros da; Santos, Paulo Sérgio da Silva; Fregnani, Eduardo Rodrigues

    2016-01-01

    This paper describes two cases in which the use of leucocyte-rich and platelet-rich fibrin (LPRF) combined with bone resection did not result in complete tissue response in the treatment of medication-related osteonecrosis of the jaw (MRONJ). It has been recently described in patients receiving subcutaneous administration of RANK-inhibitors, such as Denosumab, and anti-angiogenic drugs, such as Bevacizumab, as observed in our cases. Due to promising results in recent studies, more patients will receive these medications in order to avoid skeletal complications due to metastatic bone disease and, therefore, this scenario has a potential to become a comparable challenge to the bisphosphonate- induced jaw necrosis in the area of Oral and Maxillofacial Surgery. No convincing surgical technique has been described to overcome the non-healing mucosal lesions with exposed bone due to RANK-inhibitor therapy. Based on the findings in the literature and in both cases described herein can be concluded that the use of LPRF should be considered in the treatment of patients with DRONJ. PMID:27224573