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Mandibular overdentures supported by two or four endosseous implants  

Microsoft Academic Search

Objective: The aim of this 5-year prospective comparative study was to evaluate treatment outcome (survival rate, condition of hard and soft peri-implant tissues, patient satisfaction, prosthetic and surgical aftercare) of mandibular overdentures supported by two or four implants. Material and methods: Sixty edentulous patients with a mandibular height between 12 and 18mm participated. Thirty patients were treated with an overdenture

Anita Visser; Gerry M. Raghoebar; Henny J. A. Meijer; Rutger H. K. Batenburg; Arjan Vissink


Prosthetic complications in an implant-retained mandibular overdenture population: Initial analysis of a prospective study  

Microsoft Academic Search

Statement of Problem. The clinical success of implant-retained, tissue-supported mandibular overdenture prostheses has been documented. However, few studies have evaluated the return visits and associated cost required to maintain these prostheses. Purpose. The purpose of this investigation was to evaluate the amount of maintenance required to provide acceptable and satisfactory implant-retained mandibular overdentures in a prospective clinical trial. Material and

Nancy R. Chaffee; David A. Felton; Lyndon F. Cooper; Ulf Palmqvist; Rex Smith



Stud attachments for the mandibular implant-retained overdentures: Prosthetic complications. A literature review  

PubMed Central

A plethora of attachment systems for mandibular two-implant overdentures is currently available often without evidence-based support. Technical aspects are now parameters considered when choosing the appropriate attachment. Despite the increasing use of the Locator attachments, studies regarding their properties remain scarce. Peer reviewed articles published in English up to 2011, were identified through a MEDLINE search (Pubmed and Elsevier) and a hand search of relevant textbooks and annual publications. Emphasis was made on the technical complications as well as the loss of retention related to the attachments in implant-retained overdentures, primarily the Locator attachment. The evaluation of the long-term outcome of implant overdentures and complications associated with different attachment systems may provide useful guidelines for the clinician in selecting the type of attachment system and overdenture design.

Daou, Elie E.



Two-implant mandibular overdentures: simple to fabricate and easy to wear.  


Success rates for titanium dental implants in the anterior mandible are very high. Because of these success rates, as well as lower costs, it is common to treat edentulous patients with just 2 implants and ball anchors for retention of the overdenture, instead of 4 implants and a bar. In this paper the fabrication of 2-implant overdentures is described. In a controlled clinical trial (to be reported elsewhere), 30 subjects received a 2-implant overdenture for the mandible and a conventional prosthesis for the maxilla. The 30 control patients received conventional complete dentures for both jaws. The stability of the overdentures was excellent, and the lingual dimensions of the denture could be reduced to the level of the mylohyoid line to provide more space for the tongue. In patients with tense labial musculature or a limited amount of attached gingiva, it was important to elevate the shoulder of the implant and ball abutment above the gingival level to avoid peri-implant problems. Significantly fewer visits for adjustment related to post-placement pressure spots were required for mandibular overdentures than for conventional mandibular prostheses. PMID:12556267

Klemetti, Esa; Chehade, Antoine; Takanashi, Yoshiaki; Feine, Jocelyne S



Patient satisfaction and dissatisfaction with mandibular two-implant overdentures using different attachment systems: 5-year outcomes.  


BACKGROUND: Different attachment systems for mandibular two-implant overdentures could influence levels of patient satisfaction. Positive consensus of the majority of patients being satisfied does not preclude the possibility of dissatisfaction for some. PURPOSE: To evaluate patient satisfaction before and after 5 years of wearing mandibular two-implant overdentures using different attachment systems. MATERIALS AND METHODS: A total of 106 edentulous participants enrolled in a clinical trial completed a preliminary self-report inventory of their original complete denture complaints. New complete maxillary dentures and mandibular two-implant overdentures were provided to each participant using one of six different attachment systems. Patient satisfaction was determined at pretreatment; at baseline with mandibular two-implant overdenture insertion; and then annually for 5 years, using visual analogue and Likert-type scales. ReSULTS: Patient satisfaction with mandibular two-implant overdentures at baseline was significantly improved in all domains compared to pretreatment (old dentures) and sustained up to the 5-year recall. The level of satisfaction with Straumann gold alloy matrices at 5 years was significantly lower than that with other attachment systems. Highly significant differences were found with some social and psychological aspects by the fifth year compared to baseline. Diagnostic and prognostic indicators from a pretreatment inventory identified 12 participants (13.5%) who were dissatisfied. These indicators revealed a maladaptive predisposition to mandibular two-implant overdentures. ConclusIONS: A mandibular two-implant overdenture (opposing a conventional complete maxillary denture) will improve patient satisfaction, regardless of the attachment system. Careful evaluation of pretreatment complaints with conventional dentures can possibly identify patient dissatisfaction with mandibular two-implant overdentures. PMID:21166990

Al-Zubeidi, Mohammed I; Alsabeeha, Nabeel H M; Thomson, W Murray; Payne, Alan G T



The effect of varying implant position in immediately loaded implant-supported mandibular overdentures.  


This study was carried out to evaluate the effect of varying implant position in immediately loaded implant-supported mandibular overdentures on peri-implant bone density, muscle activity, and patient satisfaction. Fourteen completely edentulous patients were selected for the study. After complete denture construction, patients were divided into 2 equal groups. Four dental implants were installed bilaterally in the interforaminal region in the first group, while in the second group, 4 dental implants were inserted bilaterally: 2 in the interforaminal region and 2 in the first molar area. Immediately after suturing, telescopic abutments were screwed to the implants, and the retaining caps were picked up into the fitting surface of the lower denture, which was delivered to the patient. Patients were recalled for radiographic bone density evaluation just after denture delivery and then at 3, 6, and 12 months thereafter. Muscle activities of masseter and temporalis muscles as well as patient satisfaction were also evaluated. The results of the study showed a high success rate approximating 98.2% of the immediately loaded implants. The electromyographic (EMG) records of both muscles in group 1 were significantly higher during chewing hard food after 3 months compared with group 2 (P < .05). Bone density changes were comparable in the 2 groups except at the end of the follow-up period, when group 2 showed a significant increase in peri-implant bone density values of the posteriorly placed implants compared with group 1 (P < .05). From the results of this study, it may be concluded that wide distribution of immediately loaded implants used for supporting mandibular overdentures through posterior placement beyond the interforaminal area results in a favorable response in terms of increased peri-implant bone density as well as decreased EMG activity of masseter and temporalis muscles. PMID:23339758

Shaarawy, Mohammed A; Aboelross, Ehab M



Fabrication of a fractured mandibular bar-retained implant overdenture without implant-level impression making: a clinical report.  


The most frequent mechanical complications of bar-retained implant overdentures (IODs) are fracture of the dentures, loosening of the bar screws, and the need to reactivate the retentive clips. When a bar-retained IOD with an acrylic resin base fractures, the existing bar attachment should be removed to fabricate a new overdenture. So far, no method has been previously described for remaking a fractured mandibular bar-retained IOD without removing the existing bar attachment. This article describes fabrication of a fractured mandibular bar-retained IOD with distally placed ball attachments using attachment transfer analogs. The described technique allows the patient to use the existing overdenture temporarily until the new overdenture is delivered. PMID:22938207

Uludag, Bulent



Implant-supported overdenture with prefabricated bar attachment system in mandibular edentulous patient.  


Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar® is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar® was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar® system in a mandibular edentulous patient. PMID:23236580

Ha, Seung-Ryong; Kim, Sung-Hun; Song, Seung-Il; Hong, Seong-Tae; Kim, Gy-Young



The Influence of Various Attachment Types in Mandibular Implant-retained Overdentures on Maximum Bite Force and EMG  

Microsoft Academic Search

The type of attachment that is used in oral rehabilitation by means of implant-retained mandibular overdentures may influence the retention and the stability of the denture. In this study, we examined the hypothesis that a better retention and stability of the denture improve the oral function. Eighteen edentulous subjects received 2 permucosal implants, a new denture, and, successively, 3 suprastructure

F. M. C. van Kampen; A. van der Bilt; M. S. Cune; F. Bosman



Recruitment and enrollment in a randomized clinical trial of mandibular two-implant overdenture  

PubMed Central

PURPOSE The purpose of this study was to evaluate the effectiveness of a promotion campaign for subject recruitment and selection, and reasons of withdrawal from a prospective clinical trial of mandibular two-implant supported overdenture. MATERIALS AND METHODS The subjects of this study were participants in a randomized controlled clinical trial for investigating prognosis of implants and overdentures with attachments. Recruited subjects were classified by gender, age, and participation motives. Withdrawal rate of the participants before and after enrollment were evaluated. RESULTS 177 patients were recruited and 51 patients were enrolled for the trial. Among them, 40 participants eventually took part in the trial. 116 subjects (65.5%) were recruited by advertisement and 61 (34.5%) were referred by patients of the hospital or local clinics. Regarding recruitment effectiveness, newspaper recruited the largest number of participants. With respect to referral patients, the proportion of our hospital patients was higher (37/61). Subjects in their 70s comprised the largest proportion (22/51). The male to female ratio was similar (25:26). Final withdrawal rate of all subjects were 74.0%. Among the reasons for withdrawal from enrollment (n=126) presence of remaining teeth and lack of motivation were the most common reasons. CONCLUSION To facilitate recruitment of clinical trial subjects and improve enrollment rate, it is important to obtain a sufficient number of researchers, perform promotion activity with diverse strategies, cooperate with local dentists, increase the research funding, and alleviate subjects' fear against clinical trials by thorough consultation.

Lee, Jeong-Yol; Kim, Min-Soo; Kim, Ha-Young



Patients' perspectives on zirconia and titanium implants with a novel distribution supporting maxillary and mandibular overdentures: a qualitative study.  


OBJECTIVES: This qualitative study explored the perceptions of edentulous patients regarding their rehabilitation with maxillary and mandibular implant-supported overdentures employing a protocol that featured novel implant sites and distribution. MATERIAL AND METHODS: In-depth semi-structured interviews were conducted with 16 participants who have taken part in a randomized controlled trial. Each received implant overdentures supported by either titanium or zirconia one-piece implants. Participants received four implants in the maxilla and three implants in the mandible. The implant distribution was: in the maxilla, a mid-palatal implant, and three anterior implants in the incisor and first premolar regions; in the mandible, a mid-symphseal implant, and bilateral distal implants in the first molar region. All interviews were conducted by a researcher not involved with the clinical aspect of the randomized controlled trial and were transcribed verbatim and analyzed using a thematic inductive analysis approach. RESULTS: The perceived advantages of the treatment were functional improvement and increased social confidence. Cost was a significant barrier for edentulous patients seeking implant treatment. Previous experience with complete dentures, age and length of treatment was further factors that influenced decisions regarding prosthodontic rehabilitation. The novel implant protocol was acceptable to patients. CONCLUSIONS: Implant overdentures improve the quality of life of edentulous patients. Acceptance of dental implants may be increased by mitigating the cost of treatment. The mid-palatal implant site may be a potential alternative to extensive surgical procedures during the prosthodontic rehabilitation of atrophic maxillary ridges. The mandibular design offers patients the advantages of a removable prosthesis with increased retention. PMID:23278751

Osman, Reham B; Morgaine, Kate C; Duncan, Warwick; Swain, Michael V; Ma, Sunyoung



Mandibular implant-supported overdenture: an in vitro comparison of ball, bar, and magnetic attachments.  


In an implant-supported overdenture, the optimal stress distribution on the implants and least denture displacement is desirable. This study compares the load transfer characteristics to the implant and the movement of overdenture among 3 different types of attachments (ball-ring, bar-clip, and magnetic). Stress on the implant surface was measured using the strain-gauge technique and denture displacement by dial gauge. The ball/O-ring produces the optimal stress on the implant body and promotes denture stability. PMID:22891704

Manju, V; Sreelal, T



Masticatory Function with Implant-supported Overdentures  

Microsoft Academic Search

The type of attachment that is used in implant-supported mandibular overdentures may influence the retention and stability of the prosthesis and, thus, masticatory function. In this within-subject cross-over clinical trial, we examined the hypothesis that greater retention and stability of the overdenture improve the masticatory function. Eighteen edentulous subjects received 2 oral implants, a new overdenture, and, successively, 3 different

F. M. C. van Kampen; A. van der Bilt; M. S. Cune; F. A. Fontijn-Tekamp; F. Bosman



OHRQoL, masticatory performance and crestal bone loss with single-implant, magnet-retained mandibular overdentures with conventional and shortened dental arch.  


PURPOSE: The aim of this study was to assess the use of single implant-supported, magnet-retained mandibular overdentures to improve the oral health-related quality of life (OHRQoL) and masticatory performance of patients wearing conventional complete dentures. The study also aimed at comparing the OHRQoL, masticatory performance, and crestal bone loss with two different types of overdenture prosthesis. MATERIALS AND METHODS: Ten completely edentulous patients with atrophic mandibular residual alveolar ridges and having difficulty coping with technically adequate mandibular dentures were selected for implant-supported overdentures (ISOD). To assess the success of the implant fixture clinically, a crossover study design was followed, and the patients were divided into two groups. Group A received ISOD with conventional complete dental arch, and group B received ISOD with a shortened dental arch for the first 3 months and vice versa for the next 3 months. The OHRQoL was measured with the OHIP-49 questionnaire, and masticatory performance was assessed with the sieve method using peanuts as test food. Peri-apical radiographs were taken to evaluate the crestal bone loss. RESULTS: A significant improvement was seen both subjectively and objectively when conventional complete dentures were modified to implant-supported prosthesis. When comparing the implant overdenture prosthesis, patients were more satisfied with conventional arch than with the shortened dental arch. In the first 3 months following implant placement, less bone loss was seen with the shortened dental arch overdenture (P < 0.05). CONCLUSION: Single implant-supported, magnet-retained mandibular overdentures significantly improve the OHRQoL of completely edentulous patients. PMID:23331716

Grover, Manita; Vaidyanathan, Anand Kumar; Veeravalli, Padmanabhan Thallam



A randomized clinical trial comparing the efficacy of mandibular implant-supported overdentures and conventional dentures in diabetic patients. Part V: Food preference comparisons  

Microsoft Academic Search

Statement of Problem. The functional benefits of replacing old dentures with new conventional mandibular dentures or implant-supported overdentures has not been fully determined. Purpose. This study assessed the impact of these 2 types of replacement dentures on the food choices of diabetic patients. Material and Methods. A total of 68 diabetic patients with original complete dentures participated in this study.

Eleni D. Roumanas; Neal R. Garrett; Michael O. Hamada; Randy M. Diener; Krishan K. Kapur



A radiographic template for a two-implant mandibular overdenture using the patient's existing denture  

PubMed Central

This article introduces a technique for modifying an existing mandibular complete denture for use as a radiographic template with a radiopaque light-activated calcium hydroxide (Ca(OH)2) preparation. This allows prosthetically-driven treatment planning and surgical placement of 2 implants to support the existing mandibular denture.

Huynh-Ba, G; Alexander, P; Vargas, A; Vierra, M; Oates, TW



Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture.  


A hybrid denture is one that is fabricated over a metal framework and retained by screws threaded into the implant abutments. The anterior part of a mandibular hybrid denture is fixed on implants while the posterior part of the denture is extended and cantilevered from implants. This article presents the fabrication of a maxillary over-denture opposing mandibular implant retained hybrid prosthesis. A total of four implants were placed in the mandibular arch. Castable abutments were used to produce the optimal angulations. Framework was waxed, cast recovered, and the fit was refined until the framework seated passively on the master cast. The mandibular denture teeth were waxed to the hybrid framework, and a final wax try-in was performed to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verification of occlusion, retention, and stability. The rehabilitation of edentulous patients with hybrid dentures has been observed to achieve greater masticatory function and psychological satisfaction than with conventional over-dentures. Producing a passive-fitting substructure for a fixed removable screw retained hybrid prosthesis is arguably one of the most technically complex tasks in implant dentistry. The technique presented may not initially produce a perfectly passive framework, but use of disclosing media and adjusting the internal aspect of the casting can result in non-binding, fully seated prostheses. PMID:24015016

Jain, Ashish R; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew



A randomised clinical trial on the influence of splinted and unsplinted oral implants in mandibular overdenture therapy  

Microsoft Academic Search

A randomised clinical trial was performed to investigate whether there is a need or advantage to splint two implants in the\\u000a mandible retaining a hinging overdenture. Furthermore, patient satisfaction was evaluated for different attachment systems\\u000a retaining the overdenture. Thirty-six edentulous patients were randomised into three groups of equal size and treated with\\u000a either magnets, ball attachments or straight bars (reference

I. E. Naert; S. Gizani; M. Vuylsteke; D. van Steenberghe



Implant overdenture using Konus telescope on one-piece implant: a case report.  


An implant-retained Konus (tapered double crown) telescopic complete overdenture was fabricated for a mandibular edentulous patient. The Konus telescopic overdenture coping crowns and framework assembly were cast with commercially pure (CP) titanium, joined using laser welding and placed on four one-piece implants. Sufficient retention and stability were obtained using this method. PMID:20158062

Ohkubo, Chikahiro; Kobayashi, Mariko; Okamoto, Naoko; Hosoi, Toshio; Kurtz, Kenneth S; Murata, Toshiyuki



Zirconia implants supporting overdentures: a pilot study with novel prosthodontic designs.  


Limited clinical research identifies prosthodontic perspectives of novel designs for zirconia implants supporting overdentures. Four pilot study participants were selected before a planned randomized clinical trial on zirconia implants supporting overdentures. Novel designs for maxillary four-implant overdentures (quadrilateral design) and mandibular three-implant overdentures (tripodal design) were used with 28 implants (maxilla, n = 16; mandible, n = 12). Four implants failed to achieve osseointegration prior to loading. At the 1-year follow-up appointment, all implants were surviving, the overdentures were in function, and there were no clinical signs of wear of the attachment system. A proof-of-principle for prosthodontic perspectives of a novel design using one-piece zirconia implants supporting maxillary and mandibular implant overdentures was achieved. PMID:23626984

Osman, Reham B; Payne, Alan G T; Duncan, Warwick; Ma, Sunyoung


Treatment planning: implant-supported partial overdentures.  


When multiple anterior teeth are missing, many options of replacement are available. Traditionally, the choice was between a fixed or removable prostheses. Today, with the predictability of dental implants, the options of tooth replacement range from removable partial dentures to implant-supported fixed prostheses. The choice of which restoration that will best provide occlusion and esthetics depends on multiple factors including the number and location of missing teeth, the residual ridge form in relation to the replacement teeth, the relationship of the maxillary and mandibular anterior teeth, the condition of teeth adjacent to the edentulous span, the amount of bone available for implant placement, the patients "smile line" and display of teeth, lip support, and financial constraints. When there is minimal loss of the ridge contour, restorations that emerge from the ridge are the most functional and esthetic restorations, adhesive-type fixed partial dentures, conventional fixed partial dentures, and implant-supported restorations can be indicated with the choice of restoration dependent on a risk benefit and cost benefit analysis. When there is a loss of ridge contour due to residual ridge resorption or trauma, the decision becomes more complex as not only does the tooth structure need to be replaced, the ridge form also has to be replaced. (Figures 1 and 2). This can be assessed clinically as illustrated by Figures 1 and 2 where a dis crepancy in arch form and ridge form in relation to the adjacent teeth and/or opposing arch can be observed. Other considerations are lip support and display of the teeth when smiling. This article presents a case and rationale for implant-supported par tial overdentures. Many authors have written on the merits of com plete overdentures. The complete overdenture has proven to be an improvement over conventional complete prostheses with respect to chewing efficiency, patient comfort and satisfaction. In partial edentulism, the implant-supported overdenture has several advantages, some in common with a removable partial denture. PMID:15915882

Chee, Winston W L



Five- to six-year results of a prospective clinical trial using the ENDOPORE dental implant and a mandibular overdenture.  


This report is an update on a group of 46 clinical trial patients who each received 3 free-standing Endopore dental implants placed using a 2-stage surgical approach in the anterior mandible. After an initial healing interval of 10 weeks, the implants were used in each case to retain an over-denture, and at the time of the report, all patients had passed 5 years of continuous function. The 5-year cumulative "survival" rate based on a life table analysis was 93.4% and this remained unchanged after 6 years. The 5-year "success rate" was 83.3% when assessed qualitatively with the published criteria of others using a four-field table analysis categorizing every implant in the study as one of "Grade 1 Success", "survival", "unaccounted for" or "failure". Modified periodontal parameters verified continued peri-implant soft tissue health. No implant still in function had more than 1.8 mm cumulative bone loss during the first 5 years of function. These results provide clear evidence that Endopore implants despite their short lengths function at least as well as other dental implant designs used in much longer lengths. PMID:10219128

Deporter, D; Watson, P; Pharoah, M; Levy, D; Todescan, R



Retrofitting implant overdenture attachments: a clinical report.  


The remake of implant-overdenture prostheses on preexisting implants can present the clinician with a challenge, especially when the prosthetic components used initially cannot be replaced. The difficulty of remaking the prosthesis may be further increased by implant attachments designed to be cemented to the implant itself--a feature that complicates future replacement. This clinical report describes the restoration of worn implant attachments using retrofit components. PMID:12964687

Simon, Harel



Tissue-supported dental implant prosthesis (overdenture): the search for the ideal protocol. A literature review  

PubMed Central

Summary Aims The success of maxillary and mandibular tissue supported implant prostheses varies in the literature, and the ideal protocol may be elusive from given the numerous studies. The oral rehabilitation option is an alternative to conventional dentures and should improve function, satisfaction, and retention. The purpose of this review article is to clarify these questions. Methods The search of literature reviews English non-anecdotal implant overdentures articles from 1991 to 2011. Results The results display an aggregate comprehensive list of categorical variables from the literature review. Overall success of maxillary and mandibular implant overdenture was respectively, 86.6% and 95.8%. Conclusion The literature indicates that the implant overdenture prosthesis provides predictable results – enhanced stability, function and a high-degree of satisfaction compared to conventional removable dentures.

Laurito, Domenica; Lamazza, Luca; Spink, Michael J.; De Biase, Alberto



Telescopic overdenture supported by a combination of tooth and an implant: a clinical report.  


The conventional modality of treatment of partial edentulousness with reduced number of teeth was to render them complete edentulous and provide them complete denture or an overdenture with support of few remaining teeth. The goal of maintenance of roots are to prevent alveolar bone resorption, provide better load transmission, maintain sensory feedback and achieve better stability of denture with emphasis on psychological aspect of not being completely edentulous. Over the recent past titanium dental implants have been successfully used as tooth replacement with predictable results. A combination of tooth and implant support is well documented for fixed partial dentures but rarely for overdentures. This clinical report aims at evaluation of tooth root and implant supported mandibular overdenture treatment with telescopic coping. PMID:22131669

Abraham, Ponsekar A; Koka, Pradeep; Murugesan, K; Vasanthakumar, M



[Three-dimensional finite element stress analysis of magnetical retaining and bar retaining in overdenture implants].  


The purpose of this study was to determine which type of denture retaining implants can produce better biomechanical effect on the bone tissue. Two mechanical models of magnetically retained complete overdenture supported by osseo-integrated implant and bar-retained complete over denture supported by osseo-integrated implant were made. The peak stress in mandibular peri-implant bone tissue of the models were studied under the same loading conditions vertically and horizontally by three-dimensional FEM stress analysis. The results were as follows: (1) Both types of dentures retention can produce significant stress effect on the peri-implant and other regions of the jaw bone and (2) Magnetical retention is more beneficial to maintenance both of peri-implant bone tissue and long-term success of denture supported by osseo-integrated implant than bar retention does. PMID:10677962

Xu, S; Cheng, X; Hua, X



Magnet-retained implant-supported overdentures: review and 1-year clinical report.  


Open-field aluminum-nickle-cobalt magnets have been used in prosthodontics for many years, but success has been limited because these magnets are susceptible to corrosion by the saliva and because their retentive force is weak relative to the initial retention offered by mechanical attachments. More recently, magnets have been made from alloys of the rare earth elements samarium and neodymium, which provide stronger magnetic force per unit size. In addition, a new generation of laser-welded containers has improved protection from salivary corrosion. The current resurgence of interest in this type of attachment appears justified because, unlike mechanical attachments, magnets have potential for unlimited durability and might therefore be superior to mechanical ball or bar attachments for the retention of removable prostheses on implants. To date, no long-term prospective trials have been conducted to confirm the clinical durability of this new generation of magnets for retaining dentures on either teeth or implants. The aim of this study was to document initial clinical experiences and levels of satisfaction among edentulous patients treated with mandibular implant-supported overdentures retained using a new generation of rare-earth magnetic attachments. At the outset, all but one of the 17 patients had had several years of experience with implant-supported overdentures. During the first year, the mean overall satisfaction among these 17 patients increased from less than 70 to over 90 out of 100 (standardized visual analogue scale). No unusual difficulties were encountered in rendering the treatment or maintaining the attachments. This report offers preliminary evidence of the excellent potential of these magnets for retaining mandibular implant-supported overdentures. PMID:20943036

Ceruti, Paola; Bryant, S Ross; Lee, Jun-Ho; MacEntee, Michael I



A cost-effectiveness analysis of implant overdentures.  


Placement of dental implants may improve the retention and stability of complete dentures in edentulous patients. Treatment costs, however, substantially increase with implant treatment. We therefore performed a stochastic cost-effectiveness analysis, comparing implant-supported over-denture prostheses (4 implants), implant-retained overdentures (2 implants), and complete dentures, from the patient's perspective in Switzerland, to assess whether implant treatment in the mandible represents value for money spent. Twenty patients were included in each treatment group and were followed up for three years. Health outcomes were expressed in Quality-adjusted Prosthesis Years, and dental health care costs and time costs were recorded in year 2000 Swiss Francs (CHF 100 = US dollars 61). The cost per Quality-adjusted Prosthesis Year gained for implant treatment was CHF 9100 (2 implants) and CHF 19,800 (4 implants) over 3 years. Over a ten-year period, these threshold ratios were reduced to CHF 3800 (2 implants) and CHF 7100 (4 implants) per Quality-adjusted Prosthesis Year gained. PMID:16861288

Zitzmann, N U; Marinello, C P; Sendi, P



Implant-supported overdentures, a prevention of bone loss in edentulous mandibles? A 5-year follow-up study.  


The purpose of this study were to analyse 1) the changes in the bone mineral content (BMC) in mandibles with implant-supported overdentures when compared with the physiologic age-related mandibular BMC loss, 2) whether the BMC changes were different in groups without or with a bar connecting the implants and 3) whether the presence of mandibular osteoporosis affects the loss of bone height around the implants. The material consisted of 22 long-term edentulous healthy persons, 18 women and 4 men from 54 to 78 years of age with 1 Astra Tech Dental Implant in both canine regions, connected by a bar in half of the patients. BMC measurements were performed in vivo by dual-photon scanner at baseline, just after attachment insertion, at 2-year and 5-year visits. Mandibular osteoporosis was estimated by comparing baseline BMC values with normal mandibular BMC values for young adults of same gender. Loss of bone height around implants was measured on periodically identical intraoral radiographs. The fixed parts of the implant-system were stable during the trial in all patients. In conclusion: 1) the increased function after this treatment seems to cause a load-related bone formation which minimizes the physiologic age-related mandibular BMC loss, 2) this effect seems to be independent of attachment system and 3) mandibular osteoporosis prior to implant treatment may be a risk factor for bone loss around implants. However, this treatment can be recommended also in osteoporotic persons. PMID:11168267

von Wowern, N; Gotfredsen, K



Five-year clinical trial using three attachment systems for implant overdentures.  


OBJECTIVE: The objective is to compare, in a prospective randomized clinical trial, three types of attachment systems for mandibular implant overdenture, focusing on costs, maintenance requirements and complications from baseline to the end of 5-year follow-up period. MATERIALS AND METHODS: Sixty-nine fully mandibular and fully/partially maxillary edentulous patients received two screw-type Straumann implants, in the mandibular canine region. New overdentures with three types of attachment systems were inserted according to an early-loading protocol: Group B (balls, divided into Subgroup B.1 - retentive anchor with gold matrix and Subgroup B.2 - retentive anchor with titanium matrix) (n = 23), Group M (magnets) (n = 23) and Group L (locator) (n = 23). RESULTS: The highest maintenance event number (195) was observed in Group B vs. 31 in Group L and 15 in Group M. Significantly more complications were recorded in Subgroup B.1 than in Subgroup B.2, Group M and Group L (P < 0.05). Group M registered the highest prosthetic success (82.6%) in the 5 years, followed by Group L (78.2%). Subgroup B.1 had the lowest success rate (50%). The magnet group recorded statistically significant higher costs, comparing with the other two groups (P < 0.05). CONCLUSIONS: The three attachment systems functioned well after 5 years. The magnets had a low maintenance requirement and high success rate, despite the relatively increased initial costs. Retentive anchor with titanium matrix and locator may be a better choice from a financial point of view, taking into consideration the initial low cost of the components and also the reduced number of complications. PMID:23278517

Cristache, Corina Marilena; Muntianu, Ligia Adriana Stanca; Burlibasa, Mihai; Didilescu, Andreea Cristiana



Effects of superstructure type and design on force transmission via implant-stabilised mandibular prostheses.  


Forces to which individual implant units are subjected when an implant-stabilised mandibular over-denture is loaded have been measured using a carbon-fibre reinforced epoxy resin replica of an edentulous mandible mounted in a loading rig which simulated physiological conditions. Three different retentive designs were used; ball attachments, a fixed-fixed bar cranked anteriorly, and a similar design with posterior cantilevers. Forces exerted on the implants were measured using resistance strain gauges mounted on their trans-mucosal abutments and the dentures were loaded at individual tooth positions with a strain gauge beam. Ball attachments were associated with the lowest detected forces on the abutments. It is concluded that variations in superstructure design affect the forces transmitted by implants stabilising a complete mandibular over-denture, when the mandible is suspended and loaded in a physiological manner. PMID:10865379

el-Sheikh, A M; Hobkirk, J A; Kelleway, J P


Implant overdentures: dental students' performance in fabrication, denture quality, and patient satisfaction.  


The purpose of this study was to evaluate dental students' performance when fabricating a mandibular two-implant overdenture (OD) as compared to conventional dentures (CD) and to determine if these prostheses were successful. Twenty students and twenty patients were divided into two groups: complete denture group (CDG) and maxillary denture and two-implant OD group (ODG). Students' progress was evaluated at each appointment as they were given a clinical assessment score (CAS), which varied from 1 (unacceptable, needs to repeat procedure) to 4 (acceptable, no errors). The success of the prosthesis was evaluated by the patients using a visual analog scale (VAS) and an expert (a prosthodontist) using a denture quality assessment (DQA) form. Performance for both groups was not statistically different across all eight appointments (CDG 3.16 versus ODG 3.25; p=0.46). Patients with ODs reported greater stability with their dentures (p=0.048) and greater ability to chew than patients with CDs (p=0.03). There were no differences between the groups in terms of expert appraisal (ODG 71.1 versus CDG 67.5; p=0.59). The performance of dental students when fabricating a two-implant OD is thus not different from that of a CD. Students can successfully fabricate a two-implant OD as perceived by both patients and prosthodontists. PMID:20837741

Aragon, Cecilia E; Cornacchio, Angelica Lee Petrina; Ibarra, Lilia Marcela; Saad, Muhammed N; Zibrowski, Elaine



Implant Overdentures: A New Standard of Care for Edentulous Patients— Current Concepts and Techniques  

Microsoft Academic Search

While most implant-based treatment has histori- cally focused on fixed prosthetic tooth replacement, the multitude of benefits to the edentulous population from implant overdentures is overwhelming in terms of improved function, emotional stability, physical health, and esthetics. Although there still remains a lack of consistency in terms of techniques, prosthetic design, and attachment systems, these aspects have been proven less



Classification and management of restorative space in edentulous implant overdenture patients.  


A classification system of available vertical restorative space (from the crest of the soft tissue edentulous ridge to the proposed occlusal plane) is introduced for edentulous arches to be restored with implant overdentures. The Class I arch has available vertical restorative space equal to or greater than 15 mm. An arch with 12 to 14 mm of available vertical restorative space is categorized as Class II. Class III represents an arch with 9 to 11 mm of available space, while an arch with less than 9 mm of vertical restorative space is categorized as Class IV. A review of clinical procedures designed to improve vertical space availability is provided, including alveoloplasty, intentional increase of occlusal vertical dimension, occlusal plane repositioning and management of overdenture attachment selection. The authors stress the importance of considering vertical restorative space and its management for implant overdenture patients during treatment planning prior to implant placement. PMID:21530759

Ahuja, Swati; Cagna, David R



Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity  

PubMed Central

PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.

Shah, Farhan Khalid; Gebreel, Ashraf; Elshokouki, Ali hamed; Habib, Ahmed Ali



An implant-supported overdenture design with a horizontal path of insertion.  


The rehabilitation of the atrophic maxilla by means of implant-supported prostheses cannot always be achieved with fixed prostheses because of anatomic, esthetic, or economic issues, so for some patients the treatment of choice is a removable prosthesis. This article analyzes a new design for implant-supported overdentures with horizontal or faciolingual insertion. Its retention system is based on frictional forces or stepped interlocking horizontal surfaces and is appropriate for patients with skeletal Class II or III relationships with severe maxillary atrophies. The design facilitates implant-prosthetic hygiene and improved esthetics in patients with nonparallel implants by hiding abutment screws. PMID:24079557

Solá-Ruíz, M Fernanda; Agustin-Panadero, Rubén; Fons-Font, Antonio; Labaig-Rueda, Carlos



Simplified methods for fabricating tissue-supported implant-retained overdentures with retention from a resilient liner  

Microsoft Academic Search

Resilient denture liner materials can be useful for tissue-supported implant-retained overdentures. They allow physiologic movement of the denture toward the tissues. This article presents a technique that offers several advantages over other methods of fabricating the overdenture with a resilient liner, and of transferring the superstructure: the acrylic resin base and the heat-cured resilient liner material are cured simultaneously; superstructure

Sudarat Kiat-amnuay; Trakol Mekayarajjananonth; Christopher C. Cron; Zafrulla Khan; Lawrence Gettleman



A 5- to 8-year Retrospective Study Comparing the Clinical Results of Implant-Supported Telescopic Crown Versus Bar Overdentures in Patients With Edentulous Maxillae.  


Purpose: The objective of this study was to compare implant survival and success rates, peri-implant parameters, and prosthodontic maintenance efforts for implant-supported telescopic crown overdentures and bar overdentures to restore maxillary edentulism. Materials and Methods: This retrospective clinical study involved patients with maxillary edentulism who were fitted with implant-supported overdentures from January 2004 to June 2007. During a 5- to 8-year follow-up period, the implant survival and success rates, biologic and mechanical complications, prosthodontic maintenance, and patient satisfaction were retrospectively analyzed. The data were evaluated statistically and P < .05 was considered to be statistically significant. Results: Forty-four patients with maxillary edentulism received implant-supported removable overdentures. Twenty-one patients chose telescopic crown overdentures and 23 patients chose bar overdentures. A total of 41 patients and 201 implants were available for follow-up. The implant survival and success rates, average bone resorption, and subjective patient satisfaction scores showed no difference between the telescopic crown and the bar overdenture group at follow-up. However, there were higher values for Plaque and Calculus Indexes in the bar group compared with the telescopic crown group, and these values showed a statistically significant difference annually from the 3-year follow-up (P < .05). Each year, the number of prosthodontics maintenance procedures per patient did not significantly differ between the telescopic crown (approximately 0.36 to 0.58) and bar groups (approximately 0.30 to 0.49) (P = .16). Conclusions: Although there were higher plaque and calculus levels in the bar group and more maintenance was required for the telescopic crown group, overdentures provided a healthy peri-implant structure for implants in both groups. Implant-supported telescopic crown or bar overdentures can provide a good treatment option for patients with edentulous maxillae. PMID:24066324

Zou, Duohong; Wu, Yiqun; Huang, Wei; Zhang, Zhiyong; Zhang, Zhiyuan


Titanium versus zirconia implants supporting maxillary overdentures: three-dimensional finite element analysis.  


Purpose: The purpose of this study was to compare the stress and strain occurring in peri-implant bone and implants used to support maxillary overdentures. Three-dimensional finite element analysis (3D FEA) was used to compare one-piece zirconia and titanium implants. Materials and Methods: Two types of implants were simulated using a 3D FEA model: one-piece zirconia and titanium implants (diameter, 3.8 × 11.5 mm) with 2.25-mm diameter ball abutments. In each simulation four implants were placed bilaterally in the canine/premolar region of an edentulous maxillary model. Static loads were applied axially and 20 degrees buccolingually on the buccal slope of the lingual cusps of posterior teeth of the first quadrant. Von Mises stresses and equivalent strains generated in peri-implant bone and first principal stresses in the implants were calculated. Results: Comparable stress and strain values were shown in the peri-implant bone for both types of implants. The maximum equivalent strain produced in the peri-implant region was mostly within the range for bone augmentation. Under oblique loading, maximum von Mises stresses and equivalent strain were more evident at the neck of the most distal implant on the loaded side. Under axial load, the stress and strain were transferred to the peri-implant bone around the apex of the implant. Maximum tensile stresses that developed for either material were well below their fracture strength. The highest stresses were mainly located at the distobuccal region of the neck for the two implant materials under both loading conditions. Conclusions: From a biomechanical point of view, ceramic implants made from yttrium-stabilized tetragonal polycrystalline zirconia may be a potential alternative to conventional titanium implants for the support of overdentures. This is particularly relevant for a select group of patients with a proven allergy to titanium. Prospective clinical studies are still required to confirm these in vitro results. Different simulations presenting various cortical bone thicknesses and implant designs are required to provide a better understanding of the biomechanics of zirconia implants. PMID:24066336

Osman, Reham B; Elkhadem, Amr H; Ma, Sunyoung; Swain, Michael V


Fabrication of implant overdentures that are passive and biocompatible.  


Passive-fitting mesostructures and superstructures are required to be superimposed on osseointegrated endosseous implants. The tightening of an inaccurate framework to the abutments will transmit stresses to the bone-implant interface. Precision, until now, has been inconsistent and unpredictable with conventional methods of casting, soldering, and welding techniques. By machining the framework with the Spark Erosion method using electrodischarge machining, a substantial improvement in the passive seat of the prosthetic elements is achieved. Chemical reactions caused by galvanic corrosion are also important factors in the precise approach to the treatment planning of implant-supported prostheses. The application of a pure 11.8% grade 1 titanium casting system allows the restorative team to fabricate porcelain-fused-to-metal crowns and bridges, conventional fixed-removable restorations and implant prostheses in pure titanium within completely biocompatible parameters that are absolutely mercury free. This article explains why the spark erosion machining and the unique titanium casting system have a significant impact on today's implant dentistry. PMID:11307240

Renner, A M



Stress-strain distribution at bone-implant interface of two splinted overdenture systems using 3D finite element analysis  

PubMed Central

PURPOSE This study was accomplished to assess the biomechanical state of different retaining methods of bar implant-overdenture. MATERIALS AND METHODS Two 3D finite element models were designed. The first model included implant overdenture retained by Hader-clip attachment, while the second model included two extracoronal resilient attachment (ERA) studs added distally to Hader splint bar. A non-linear frictional contact type was assumed between overdentures and mucosa to represent sliding and rotational movements among different attachment components. A 200 N was applied at the molar region unilaterally and perpendicular to the occlusal plane. Additionally, the mandible was restrained at their ramus ends. The maximum equivalent stress and strain (von Mises) were recorded and analyzed at the bone-implant interface level. RESULTS The values of von Mises stress and strain of the first model at bone-implant interface were higher than their counterparts of the second model. Stress concentration and high value of strain were recognized surrounding implant of the unloaded side in both models. CONCLUSION There were different patterns of stress-strain distribution at bone-implant interface between the studied attachment designs. Hader bar-clip attachment showed better biomechanical behavior than adding ERA studs distal to hader bar.



Performance of attachments used in implant-supported overdentures: review of trends in the literature  

PubMed Central

The purpose of this review is to examine the performance of attachments used in implant-supported overdenture (IOD) in both clinical and in vitro settings and report the compiled findings, comparisons, and trends in the research literature. Articles published in PubMed on IOD attachment systems and performance were reviewed. Non-original articles were excluded. For each article included, the type of study, number of implants, number of attachment systems, and study outcome were recorded. Of the 283 articles found, 158 met the inclusion criteria. Ninety-four articles were clinical studies and 64 articles were in vitro studies. Studies on retention were the most common for in vitro studies, and four or more attachment systems were compared in most articles with significant differences in outcome. A clinical outcome of one attachment system was most common for clinical studies, while most studies had neutral outcomes overall. Ball attachment was the most commonly tested IOD attachment system. The trend in the literature showed that there is a large discrepancy between the study designs and outcomes between the clinical and the in vitro studies for IOD. Further clinical studies that can validate in vitro research should be encouraged to address this discrepancy between the two areas.



Overdentures--when and how.  


Implant borne overdentures are a reliable and simple solution to denture retention and stability problems. Such a treatment option requires careful planning and the basis for this is made from the results of clinical trials. An overdenture symposium on this subject was held at Naantali, Finland on 26th August, 1994. The following paper is a summary of the proceedings. PMID:9080745

Walmsley, A D; Nilner, K



21 CFR 874.3695 - Mandibular implant facial prosthesis.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3695 Mandibular implant facial prosthesis...device is made of materials such as stainless steel, tantalum, titanium, cobalt-chromium based alloy,...



Immediate implant placement in posterior areas: the mandibular arch.  


When contemplating removal of a premolar or molar and its immediate replacement with an implant-supported prosthesis, the feasibility of other potentially less "aggressive" treatment approaches must first be considered. Treatment decisions must be made in the context of an appropriate definition of therapeutic success. Replacement of hopeless mandibular molars with implant restorations has undergone significant evolution since the introduction of osseointegrated implants some 30 years ago. Over the past decade, various treatment approaches have been advocated. This article discusses these approaches and other considerations needed for implant placement at the time of mandibular molar extraction. PMID:22908599

Fugazzotto, Paul A; Hains, Frederick O


Sensory perception in overdenture patients.  


The discussion of overdentures has been confined to their capacity to use abutment teeth to improve neuromuscular control of mandibular movement. Use of overdentures has been favored often because of their mechanical advantages, but seldom because of the sensory role of the retained abutment teeth. Even though the retained teeth may be periodontally diseased, they still may provide sufficient support for the transmission of masticatory pressures and sufficient periodontal ligament receptors to initiate a jaw opening reflex. Whereas conflicting evidence shows that the periodontal nerve receptors play a role in mandibular positional sensibility (proprioception), pressure perception by the periodontal ligament remains a primary stimulus for the jaw opening reflex. Additional investigations will be essential to a complete understanding of the role of the periodontal ligament receptors. However, recognition of the importance of the periodontal ligament receptors to the overdenture patient as a source of sensory input is vital. PMID:1066472

Kay, W D; Abes, M S



Repair of a milled cantilevered implant overdenture bar: a clinical report.  


This clinical report of a fractured cantilevered substructure bar describes an alternative treatment to the proposed refabrication of the substructure bar and overdenture prosthesis. This report outlines the clinical and laboratory procedures to repair the fractured bar, eliminating the time and expense of fabricating a new bar and prosthesis. PMID:16911883

Rasmussen, Jonathan M; Koka, Sreenivas; Eckert, Steven E; Lee, Richard D



Five-Year Follow-up of Modified Implant-Supported Overdenture in an Iliac Crest Autograft Failure: Clinical Report.  


The treatment of extensive pathologic lesions in the jaw, most of the time, can generate rehabilitation problems to the patient. The solid ameloblastoma is a locally invasive odontogenic tumor with a high recurrence rate. Its treatment is aggressive and accomplished through resection with safety margin. The criterion standard for reconstruction is autogenous bone, but it can provide a high degree of resorption, causing inconvenience to the patient because of lack of rehabilitative option. This study aimed to describe a patient with ameloblastoma treated through resection and reconstruction with autogenous bone graft, in which, after an extensive resorption of the graft was made, a modified bar was applied to support a prosthetic implant overdenture. PMID:24036834

Dos Santos Pereira, Rodrigo; Boos, Fernanda Brasil Daura Jorge; Lourenço, Eduardo José Veras; Hochuli-Vieira, Eduardo; da Costa Rodrigues, Paulo; Homsi, Nicolas



Predictable immediate loading of mandibular implants.  


Technological advancements have resulted in modern dental implant protocols that provide the possibility to immediately load implants in fresh extraction sockets. This article briefly addresses various aspects to be considered such as computed tomography (CT), surgical guides, implant considerations for the edentulous patient, and considerations for immediate implant placement and loading. In this clinical case, immediate post-extraction implant placement with immediate loading was performed accurately because of the planning done with the CT scan. The use of a stereolithographic model and a surgical guide prevented technical difficulties and improved the predictability during the prosthetically driven surgery. PMID:24015451

Afrashtehfar, Kelvin I; Cárdenas-Bahena, José T; Afrashtehfar, Cyrus D M



Advanced implant overdenture superstructure treatment planning with computer-assisted design systems.  


The amount of available space between the residual ridge crest and the prosthetic teeth provide a challenge not only for the clinician but also for the dental technologist. This technical report demonstrates the applied use of a touch probe scanner (Pix30 3D Scanner, Dr. Picza, Roland DG Corporation; Irvine, CA, USA) used in conjunction with computer-assisted design (CAD) programs to reduce clinical chair time as well as reduce the cost of intraoral and laboratory components. Tooth arrangement and superstructure are scanned and positioned in various CAD programs to measure the available space for the superstructure. While there are limitations in the accuracy of the scanning process, these limitations have little effect on the treatment planning for complete overdentures as well as fixed prostheses. Once the scanning is complete, CAD programs can be used to improve planning, resulting in less wasted material, fewer errors in diagnosis, and reduction both in overall clinical and laboratory costs and clinical chair time. PMID:20481291

Karimi-Boushehri, F; Cable, C



Physical and metallurgical considerations of failures of soldered bars in bar attachment systems for implant overdentures: a review of the literature.  


The purpose of this literature review was to identify the etiological factors of failure of soldered bars in bar attachment systems for removable implant overdentures. A search of MEDLINE using the key words "bar attachment systems" was performed of English language peer-reviewed journals published between 1975 and 2005. Clinical studies of implant overdentures with prosthodontic maintenance complications of bar attachment systems were identified to establish the perceived etiology of failure. A further search of MEDLINE using the key words "solder joint" was also performed of the fixed prosthodontic literature to identify specific factors affecting the strength, fatigue resistance, and quality of gold solder joints used for bar attachment systems. The first search on bar attachment systems produced evidence of low failure rates of interabutment bars, but higher failure rates of bars where distal cantilever extensions were used. There were no explanations or descriptions of the nature of those failures in the clinical studies reviewed. The second search on fixed prosthodontic literature identified multiple factors that could potentially relate to the failed solder joints with bar attachments. Two potential sites of failure in bar attachments with distal cantilevers were identified, and a simple estimate of the tensile stresses at the solder joints was performed. The values found are comparable to the fatigue failure stresses reported in the searched literature. PMID:17052473

Waddell, J Neil; Payne, Alan G T; Swain, Michael V



Plastic Surgery at the Time of Membrane Removal Around Mandibular Endosseous Implants: A Modified Technique for Implant Uncovering  

Microsoft Academic Search

Removal of barrier membranes may complicate second-stage implant surgery, par- ticularly in mandibular areas characterized by a shallow vestibule and minimal amount of keratinized tissue. A new surgical technique that permits implant expo- sure and membrane removal combined with a plastic procedure to improve soft tis- sue quality both buccally and lingually is presented. A midcrestal incision preserv- ing the

Luca Landi; DDS Domenico Sabatucci


Bone resection, extra-corporal cryotherapy and immediate re-implantation in the treatment of mandibular tumours.  


Two aspects have to be considered in the treatment of mandibular tumours: The eradication of the disease, and the maintenance of mandibular continuity to obtain a good functional and aesthetic result. The authors experimented with a cryo-surgical method which consists of mandibular hemiresection, extra corporal immersion of the specimen in liquid nitrogen at - 180 degrees C, followed by re-implantation of the mandibular body in its bed. In this way we achieved the eradication of the tumour and produced an auto-transplant for immediate bone grafting. The clinical and radiological progress of four patients with various mandibular tumours, followed-up for three years, is presented. PMID:6929866

Popescu, V; Spirescu, I E



Mandibular fracture after endosseous implant placement in conjunction with inferior alveolar nerve transposition: a patient treatment report.  


A patient with a severely atrophic right posterior mandible had three endosseous implants placed in conjunction with transposition of the inferior alveolar nerve. Three weeks following implant placement surgery, the patient experienced a spontaneous fracture of the mandible involving the two anterior implants. The two implants were removed, and the fracture was treated with open reduction and fixation with titanium mesh. The fracture healed, and the posterior implant integrated. This report suggests that the buccolingual and superior-inferior position of the mandibular canal can increase the possibility of mandibular fracture by increasing the size of the buccal cortical plate that is removed to expose the nerve during surgery. PMID:9337027

Kan, J Y; Lozada, J L; Boyne, P J; Goodacre, C J; Rungcharassaeng, K


Removable partial overdentures with mechanical (precision) attachments.  


Mechanical attachments for overdentures have been available in various forms for over a century. The explosive interest in osseointegration and the effort on the part of the profession to avoid the complete denture as a treatment modality has stirred the interest in positive retentive elements for overdentures represented by the mechanical stud and bar attachments. The cited references provide a resource as a trouble-free guide in the selection and use of the various stud and bar attachment systems. The clinical examples show a pattern of application not generally discussed by the manufacturers, illustrating the simplicity of use with the options for all attachments including magnets. The discussion on magnets comes from 9 years of clinical experience. Rare earth magnets provide excellent adjunct retention, and their assembly follows the same protocol and complexity as stud attachment systems. All magnets, at the present state of the art, have a corrosion potential with the exception of the Laser Sealed Units (Golden Dental, Golden, CO). Finally, the mechanics of the attachment overdenture serves as an excellent training field for the osseointegrated prosthesis, be it the classic Brånemark (Nobelpharma USA, Chicago, IL) restorative or the implant overdenture concept. PMID:2227040

Mensor, M C



Magnetic attachment for implant overdentures: influence of contact relationship with the denture base on stability and bending strain.  


This study evaluated how the contact height between the magnetic attachment and denture base influences stability and bending strain. An implant modified with strain gauges and a magnetic attachment mounted in an acrylic resin block were used to characterize systems with varying degrees or heights of contact with the abutment. Bending strain under lateral loading increased significantly as the contact height decreased. In the no contact and resilient contact groups, magnetic assemblies separated at reduced bending strain in all loading conditions. The contact height of the magnetic attachment influenced the stability and the amount of bending strain on the implant. PMID:24179971

Yang, Tsung-Chieh; Maeda, Yoshinobu; Gonda, Tomoya; Wada, Masahiro


Use of Orthodontic Mini-Implants for Maxillomandibular Fixation in Mandibular Fracture  

PubMed Central

Orthodontic appliances for skeletal anchorage are becoming increasingly more common in clinical practice. Similarly, different terms such as mini-implants, microimplants, and miniscrews have been used. There is a wide array of appliances currently on the market, in different designs and sizes, diameters, degree of titanium purity, and surface treatment. These appliances have been used for a variety of indications, including tooth retraction, intrusion, and traction. This study aimed to report the clinical case of a 19-year-old patient with a fractured mandible and to propose a novel use of mini-implants: the perioperative placement of mini-implants as anchors for maxillomandibular fixation steel wire ligatures. We concluded that this appliance provides an effective maxillomandibular fixation in patients with mandibular fracture, with little increase in the cost of surgery.

Pires, Mario Sergio Medeiros; Reinhardt, Leandro Calcagno; Antonello, Guilherme de Marco; Torres do Couto, Ricardo



Alveolar ridge augmentation with calvaria, iliac crest and mandibular autologous bone grafts: a retrospective study on 261 implants  

Microsoft Academic Search

Summary  PURPOSE: In the last decade, several investigators have reported that autografts can be used to restore alveolar volume prior\\u000a to implant insertion successfully. However, no report is available comparing implant inserted into calvarial, mandibular and\\u000a iliac crest bone autografts. MATERIALS AND METHODS: A retrospective study on 261 implants inserted in 42 patients was performed.\\u000a Several variables related to patients, anatomic

R. Cenzi; L. Arduin; I. Zollino; C. Casadio; A. Scarano; F. Carinci



Measuring the Effect of Intraoral Implant Rehabilitation on Health-related Quality of Life in a Randomized Controlled Clinical Trial  

Microsoft Academic Search

The importance of assessing the impact of treatments for chronic conditions on an individual's quality of life has been well-established. In this randomized clinical trial, oral-health-rclated quality of life, measured with the Oral Health Impact Profile (OHIP), was compared between two groups of edentulous patients. One group (n = 54) received mandibular implant-supported overdentures, and the other group (n =

M. A. Awad; D. Locker; N. Korner-Bitensky; J. S. Feine



Full mouth rehabilitation of a hypohidrotic ectodermal dysplasia patient with dental implants: a clinical report.  


Prosthodontic treatment in patients with ectodermal dysplasia (ED) is difficult to manage because of the oral deficiencies typical in this disorder and because afflicted individuals are quite young when they are evaluated for treatment. This clinical report describes an 18-year-old patient with hypohidrotic ED treated with dental implants. Treatment included a maxillary implant overdenture and a mandibular hybrid prosthesis supported by osseointegrated implants. At the one-year follow-up, the patient presented significant improvements in oral function and psychosocial activities. PMID:17581183

Rad, Afsaneh Shahrokhi; Siadat, Hakimeh; Monzavi, Abbas; Mangoli, Amir-Ali


Implant-supported fixed restoration of post-traumatic mandibular defect accompanied with skin grafting: A clinical report  

PubMed Central

Traumatic defects are mostly accompanied by hard and soft tissue loss. This report describes the surgical and prosthetic treatment of a patient with post-traumatic mandibular defect. A split-thickness skin graft was performed prior to implant placement and prefabricated acrylic stent was placed to hold the graft in place. The esthetic and functional demands of the patient were fulfilled by implant-supported screw-retained fixed prosthesis using CAD-CAM technology.

Noh, Kwantae; Choi, Woo-Jin



Mandibular reconstruction using autologous iliac bone and titanium mesh reinforced by laser welding for implant placement.  


Segmental mandibulectomy is a treatment option for benign and malignant neoplasms of the mandible. Although reconstructing the mandible of a patient with a missing segment is difficult, it is essential to improve the postoperative course of the patient. Mandibular reconstruction using titanium mesh is a useful technique for dental implant placement because the morphology of the mandible can be easily reproduced. However, fitting titanium mesh to the remaining mandible is not an easy task during surgery. The present report introduces a method in which a 3-dimensional skull model fabricated by means of stereolithography is prepared, based on computerized tomography (CT) scans, to construct a titanium mesh cage matching the shape of the mandible, preoperatively. Furthermore, the load-bearing area of the titanium mesh cage is reinforced by laser welding another layer of titanium mesh to reduce the incidence of metal fatigue during jaw movement. PMID:19216287

Yamashita, Yoshio; Yamaguchi, Yoshimasa; Tsuji, Mitsuhiro; Shigematsu, Masahito; Goto, Masaaki


Stress analysis of an overdenture using the finite element method.  


The purpose of this study was to examine the influence of reinforcing the structure of an overdenture on stress distribution in the residual ridge using the three dimensional finite element method. Four models of mandibular overdentures with various reinforcement methods were analyzed, including (1) without reinforcement, (2) with chrome-cobalt reinforcing wire, (3) with a reinforcing structure (a cast metal framework) and no reinforcement on the coping top, and (4) with a reinforcing structure and reinforcement on the coping top. The reinforcement adjacent to the top of the coping and the medial part reduces the stress beneath the loading side of dentures and widely and evenly distributes the stress of the residual alveolar ridge. PMID:23837164

Gonda, Tomoya; Dong, Jian; Maeda, Yoshinobu


Dental implant performance in vertically distracted fibular grafts after mandibular reconstruction: a pilot series of 12 patients.  


Purpose: To clinically and radiographically evaluate the performance of loaded dental implants placed in vertically distracted fibular grafts after mandibular reconstruction, and to evaluate patient satisfaction with implant function and esthetics after oral rehabilitation. Materials and Methods: This retrospective study involved patients who received implants in vertically distracted fibular bone after mandibular reconstruction between February 2006 and January 2008. Clinical assessments were performed 6 months after loading and annually thereafter. Patient satisfaction was evaluated with respect to function, phonetics, facial contour esthetics, and oral hygiene practices. The data were evaluated statistically. Results: Thirty-seven dental implants were inserted in 12 patients (mean age, 42.9 ± 8.0 years). Three patients were completely edentulous and nine were partially edentulous. The low mean plaque score (< 20%) indicated a good level of oral hygiene during the mean follow-up period of 42.1 ± 4.1 months. Probing depths and modified Sulcus Bleeding Index increased slightly at follow-up, but there was no significant difference in either parameter at years 1 and 3. After 1 year, the average marginal bone loss was 0.8 ± 0.3 mm (range, 0.2 to 2.1 mm); this increased to 0.9 ± 0.4 mm (range, 0.5 to 2.4 mm) in year 3, which was not a significant difference. The cumulative survival rate was 100% and the cumulative success rate was 84.8%. Seven of the 12 patients were fully satisfied with the function and esthetics of the restoration. Conclusions: On the basis of the present study, implant placement in vertically distracted fibulae for mandibular reconstruction may be considered a predictable option in terms of mid- to long-term implant survival and success rates. PMID:24066323

Wang, Feng; Wu, Yiqun; Zhang, Chenping; Zhang, Zhiyong




Abstract Ameloblastomas are benign odontogenic tumors that develop from the epithelial rests of Malassez. This case reports the multi-disciplinary treatment of an extensive ameloblastoma including reconstruction with free bone flaps and dental implants and acellular dermal matrix graft. Segmental mandibular resection followed by reconstruction with free iliac crest bone flap was performed. Following six months of healing, 7 dental implants were performed. After six months, clinical examinations revealed existence of a mucogingival problem associated with lack of keratinized tissue at the peri-implant region and acellular dermal matrix graft was performed prior to second stage surgery. Following healing of 3 months, second stage surgery was performed and dental implant supported fixed prosthesis was delivered.The patient tolerated the procedures well. At 3rd month and 6th month follow-ups, clinical and radiographic examinations revealed favorable soft tissue and bone health. Following delivery of prosthesis, the patient was competent about the aesthetic and functional results achieved. Multidisciplinary treatment of extensive ameloblastomas with radical resection, free iliac crest bone flap and dental implants increase the quality of life for patients at both aesthetic and functional aspects. Frequent maintenance procedures and increasing the keratinized tissue at the peri-implant region are suggested for long term success of dental implants placed in reconstructed sites. PMID:23506101

Buyukozdemir Askin, Sezen; Aksu, Ali Emre; Cal?s, Mert; Tulunoglu, Ibrahim; Safak, Tunc; Tozum, Tolga Fikret



Pain Sensation and Postsurgical Complications in Posterior Mandibular Implant Placement Using Ridge Mapping, Panoramic Radiography, and Infiltration Anesthesia  

PubMed Central

Objectives. The aim of this study was to investigate intrasurgical and after surgical, pain and the incidence of after surgical alteration of sensation in the mandible and lower lip when placing implants in the posterior mandible using ridge mapping, panoramic radiography, and infiltration anesthesia. Methods. This was a longitudinal clinical study of healthy patients needing implant placement in the posterior mandible. After thorough examination and treatment plan using ridge mapping and panoramic radiography, all patients received dental implants under local infiltration anesthesia. The patients were then given a questionnaire to assess the pain during anesthesia and implant surgery. Change of sensation in the lower lip was evaluated by standard neurosensory examination tests at 7 days and 1 and 4 months. Prosthetic treatment was carried out 4 months postsurgery and the patients were followed for an average of 28.5 months afterwards. Results. A total of 103 implants were placed in 62 patients. Patients reported very minor pain during injection. No pain was reported during either implant placement or bone grafting procedures. No alteration of sensation in the mandible or lower lip was recorded postsurgery. Conclusion. In most cases, ridge mapping, panoramic radiography, and infiltration anesthesia are sufficient for posterior mandibular implant placement without pain or complications.



Influence of ridge inclination and implant localization on the association of mandibular Kennedy class I removable partial denture.  


The aim of this study was to evaluate the tendency of displacement of the supporting structures of the distal extension removable partial denture (DERPD) associated to the implant with different inclinations of alveolar ridge and implant localizations through a two-dimensional finite-element method. Sixteen mandibular models were fabricated, presenting horizontal, distally descending, distally ascending, or descending-ascending ridges. All models presented the left canine and were rehabilitated with conventional DERPD or implant-retained prosthesis with the ERA system. The models were obtained by the AutoCAD software and transferred to the finite-element software ANSYS 9.0 for analysis. A force of 50 N was applied on the cusp tips of the teeth, with 5 points of loading of 10 N. The results were visualized by displacement maps. For all ridge inclinations, the assembly of the DERPD with distal plate retained by an anterior implant exhibited the lowest requisition of the supporting structures. The highest tendency of displacement occurred in the model with distally ascending ridge with incisal rest. It was concluded that the association of the implant decreased the displacement of the DERPD, and the anterior positioning of the implant associated to the DERPD with the distal plate preserved the supporting structures for all ridges. PMID:21558932

Cunha, Lígia Del' Arco Pignatta; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Goiato, Marcelo Coelho



Edentulous maxillary arch fixed implant rehabilitation using a hybrid prosthesis made of micro-ceramic-composite: case report.  


The prosthetic treatment of patients with an edentulous maxilla opposing mandibular natural teeth is one of the most challenging endeavors that face clinicians. Occlusal forces from the opposing natural teeth may cause fractures in the maxillary prosthesis and also result in advanced bone loss of the edentulous maxilla. With the presence of extreme gagging reflex, the treatment may become more complicated. This article describes and illustrates the 2-stage surgical and prosthetic treatment of a patient with an edentulous maxilla opposing natural teeth. In the beginning, the patient was treated with 4 implants and a maxillary implant-supported overdenture. The extreme gagging reflex and the occlusal forces from the mandibular natural teeth obligated the team a second stage surgical and prosthetic treatment, which included increasing the number of implants after bilateral sinus lifting in the posterior maxilla and fabricating a maxillary fixed hybrid prosthesis made of micro-ceramic composite that yielded a satisfactory result. PMID:20932120

Geckili, Onur; Bilhan, Hakan; Ceylan, Gulsum; Cilingir, Altug



Evaluation of immediately loaded dental implants bioactivated with platelet-rich plasma placed in the mandibular posterior region: A clinico-radiographic study  

PubMed Central

Background and Objectives: The purpose of the present study was to clinically and radiographically assess the soft and hard tissue changes around the immediately loaded single tooth implants bioactivated with platelet-rich plasma (PRP), placed in the mandibular posterior region. Materials and Methods: A total of 11 patients having single tooth edentulous space in the mandibular posterior region were selected. An endosseous implant was placed after clinical and radiographic examination in each selected site using single stage surgical approach. The patients were followed up at 3, 6, 9, and at 12 months of post implant insertion. The patients were subjected to recording of clinical parameters like modified plaque index, modified gingival index, probing depth, and clinical implant mobility scale. Radiographs made at different intervals were subjected to assessment of bone level mesial and distal to each implant using computer assisted image analysis. Results: Scores for clinical parameters were minimal and comparable. The probing depth around the implant was measured during the follow-up period and the changes observed were statistically non-significant. None of the implants were clinically mobile during the follow-up period. Radiographically, the peri-implant bone resorption both on mesial and distal sides was within normal limit after one year of immediate loading. Finally, the overall success rate for the immediately loaded bioactivated implant placed in the mandibular posterior region was recorded as 100%. Interpretation and Conclusion: The use of platelet-rich plasma may lead to improved early bone apposition around the implant; and thus, results in increased rate of osseointegration. Single stage implant procedure with the adjunctive use of PRP enhances the ability of peri-implant healing tissue to create favorable soft and hard tissue relationships. It also gives the added advantage of psychological boost for the patient by getting fixed replacement of tooth within a short time period.

Anand, Ullas; Mehta, D. S.



An overview of removable partial overdentures.  


As an alternative to complete dentures, overdentures are well established as a sound therapeutic modality for patients with terminal dentition. By utilizing natural tooth roots and their periodontal structures to aid in support, overdentures maintain proprioceptive mediation and a mechanism for masticatory force vectors that favor bone retention over bond resorption. The degree of stability enhancement and denture retention from retained roots varies with the design and environment of the prosthesis. This article reviews various aspects of removable partial over-denture use. PMID:2198103

McDermott, I G; Samant, A



The Effect of Implant Shape and Screw Pitch on Microdamage in Mandibular Bone.  


PURPOSE: The aim of this study was to investigate the effect of implant shape and screw pitch on microdamage in bone during insertion of dental implants. MATERIALS AND METHODS: Thirty custom-made implants (length, 10?mm; diameters, 4.1?mm; cylindrical, tapered, and taper-cylindrical shapes; screw pitches, 1.25 and 0.8?mm; classified as 1.25C, 0.8C, 1.25T, 0.8T, 1.25TC, 0.8TC) were placed with a surgical device in the mandibles of eight goats. Two implant sites were prepared in the edentulous area on each side of the mandible. Implants were placed in a randomized order. Immediately after placement of the implants, the bone blocks with the implants were collected, bulk stained with basic fuchsin, embedded in methyl methacrylate, and sectioned. Histomorphometric quantification of the microcrack length (Cr.Le, ?m); microcrack surface density (Cr.Le/B.Ar, ?m/mm(2) ), and damaged bone area fraction (DB.Ar/B.Ar, %) were measured. RESULTS: The Cr.Le, Cr.Le/B.Ar, and DB.Ar/B.Ar values of 0.8TC group were 80.96?±?17.55, 478.75?±?51.85, and 4.40?±?0.36, respectively. All these parameters of microdamage induced by 0.8TC were significantly lower than those induced by other five types of implants (p?implants with 0.8?mm screw pitch caused the least microdamage to the bone in comparison with the other five types of implants during placement of implants. PMID:23763648

Xu, Chendi; Wei, Zhong; Liu, Nizhou; Sun, Fei; Chen, Hui; Lin, Tingting; Zhang, Baowei; Tang, Tingting; Lu, Eryi



Influence of implant inclination associated with mandibular class I removable partial denture.  


The aim of this study was to use two-dimensional finite element method to evaluate the displacement and stress distribution transmitted by a distal extension removable partial denture (DERPD) associated with an implant placed at different inclinations (0, 5, 15, and 30 degrees) in the second molar region of the edentulous mandible ridge. Six hemimandibular models were created: model A, only with the presence of the natural tooth 33; model B, similar to model A, with the presence of a conventional DERPD replacing the missing teeth; model C, similar to the previous model, with a straight implant (0 degrees) in the distal region of the ridge, under the denture base; model D, similar to model C, with the implant angled at 5 degrees in the mesial direction; model E, similar to model C, with the implant angled at 15 degrees in the mesial direction; and model F, similar to ME, with the implant angled at 30 degrees in the mesial direction. The models were created with the use of the AutoCAD 2000 program (Autodesk, Inc, San Rafael, CA) and processed for finite element analysis by the ANSYS 8.0 program (Swanson Analysis Systems, Houston, PA). The force applied was vertical of 50 N on each cusp tip. The results showed that the introduction of the RPD overloaded the supporting structures of the RPD and that the introduction of the implant helped to relieve the stresses of the mucosa alveolar, cortical bone, and trabecular bone. The best stress distribution occurred in model D with the implant angled at 5 degrees. The use of an implant as a support decreased the displacement of alveolar mucosa for all inclinations simulated. The stress distribution transmitted by the DERPD to the supporting structures was improved by the use of straight or slightly inclined implants. According to the displacement analysis and von Mises stress, it could be expected that straight or slightly inclined implants do not represent biomechanical risks to use. PMID:21415633

de Freitas Santos, Ciandrus Moraes; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; de Moraes, Sandra Lúcia Dantas; Falcón-Antenucci, Rosse Mary



Piezoelectric surgery in mandibular split crest technique with immediate implant placement: a case report  

PubMed Central

SUMMARY Implant supported rehabilitation of thin edentulous ridges with horizontal atrophy necessitates a regenerative approach. Within the procedures for horizontal bone defects augmentation, ridge expansion techniques permit dislocation of the buccal bone plate in a labial direction and simultaneous implant insertion in single-stage surgery, abbreviating overall treatment time. The piezoelectric ridge expansion technique permits to obtain the expansion of very mineralized bone crests without excessive traumas or the risk of ridge fractures. The case reported shows an implant treatment for partial edentulous lower arch rehabilitation. A full-split thickness flap was raised. The mucoperiosteal reflection permitted to identify alveolar crest contour where osteotomies had to be performed. Split thickness dissection allowed periosteal blood supply to be mainteined on the buccal bone plate. After horizontal and vertical osteotomies were performed with OT7 piezoelectric microsaw (Piezo-surgery, Mectron), a single-bevel scalpel was used to move the buccal bone plate to the labial. Two Straumann TE 3.3/4.8 mm wide implants were inserted in the lower right premolar area, and 1 Straumann 4.8 mm Wide Neck implant was inserted to replace lower right first molar. The amount of bone expansion was equal to the cervical diameter of the placed implants (4.8 mm) and residual bone gap was packed with Bio-Oss granules (Geistlich). Healing was uneventful and 3 months later final restorations with implant-supported porcelain-fused-to-metal crowns were cemented.




Prosthetic rehabilitation of head and neck cancer patients focusing on mandibular dentures in irradiated patients.  


Purpose: This retrospective study assessed treatment outcomes and patient satisfaction of irradiated head and neck cancer patients treated with mandibular implant overdentures (IODs) or conventional dentures (CDs). Materials and Methods: Fifty-one irradiated head and neck cancer patients, out of a total of 158 patients included, completed the standardized questionnaire and underwent a clinical assessment. Nineteen patients were treated with removable CDs and 32 patients received IODs between January 2006 and January 2011. The mean follow-up of patients was 5.75 years (range: 1 to 23 years). Results: A total of 45 (88.3%) mandibular dentures were in function at the time of assessment. The overall denture satisfaction was 7.3 (range: 1 to 10, SD: 2.14). Patients being treated with adjuvant concepts, including surgical tumor ablation, scored worse than patients after radiation therapy alone. Edentulous patients seem to benefit from implants, especially with respect to prosthesis retention. Men take more benefit from IODs compared with women. Conclusions: The results are comparable to other studies of head and neck cancer patients and also of healthy individuals. Surgical interventions in adjuvant therapy concepts lead to reduced denture satisfaction. The concept of prosthetic rehabilitation as part of oncologic treatment can be judged as successful. PMID:24179970

Buurman, Doke J M; Vaassen, Lauretta A; Bockmann, Roland; Kessler, Peter


Evaluation of impression accuracy for a four-implant mandibular model--a digital approach.  


Implant-supported prosthodontics requires precise impressions to achieve a passive fit. Since the early 1990s, in vitro studies comparing different implant impression techniques were performed, capturing the data mostly mechanically. The purpose of this study was to evaluate the accuracy of three different impression techniques digitally. Dental implants were inserted bilaterally in ten polymer lower-arch models at the positions of the first molars and canines. From each original model, three different impressions (A, transfer; B, pick-up; and C, splinted pick-up) were taken. Scan-bodies were mounted on the implants of the polymer and on the lab analogues of the stone models and digitized. The scan-body in position 36 (FDI) of the digitized original and master casts were each superimposed, and the deviations of the remaining three scan-bodies were measured three-dimensionally. The systematic error of digitizing the models was 13 ?m for the polymer and 5 ?m for the stone model. The mean discrepancies of the original model to the stone casts were 124 ?m (±34)??m for the transfer technique, 116 (±46)??m for the pick-up technique, and 80 (±25)??m for the splinted pick-up technique. There were statistically significant discrepancies between the evaluated impression techniques (p ? 0.025; ANOVA test). The splinted pick-up impression showed the least deviation between original and stone model; transfer and pick-up techniques showed similar results. For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws. PMID:22009182

Stimmelmayr, Michael; Erdelt, Kurt; Güth, Jan-Frederik; Happe, Arndt; Beuer, Florian



Fixed mandibular and maxillary implant rehabilitation in a fully edentulous patient: a case report.  


The complete dental rehabilitation of a patient with a failing dentition using fixed implant-supported prostheses requires carefully planned and well-sequenced treatment. This case report presents the treatment steps and sequencing for a patient in whom removable provisional prostheses were not an option. While an immediate loading protocol was used in the mandible, a staged approach featuring strategic extractions and implant placement in several phases was applied in the maxilla. The major advantage of this treatment protocol was that the patient was maintained in fixed prostheses throughout the treatment. PMID:20072739

Wittneben, Julia-Gabriela; Avdic, Mersiha; Wright, Robert F; Radics, Andreas; Gallucci, German O; Weber, Hans-Peter



Replacement of mandibular posterior teeth with implants in a postmandibular resection case: a case report.  


This case report describes the prosthetic rehabilitation of a patient who was treated for ameloblastoma by segmental resection of the mandible. Because of the size of the defect it was decided to use a healing obturator to facilitate bone formation in the defect. At the end of 3 months, bone formation had led to complete obliteration of the defect with an almost complete fill to the crest of the ridge. The next phase of the treatment was prosthetic rehabilitation. The patient preferred a fixed replacement of teeth as opposed to a removable option. The final treatment plan was an implant-supported fixed prosthesis that was progressively loaded. PMID:21905914

Christian, Jayanth; Grover, Manita; Veeravalli, Padmanabhan Thallam



[The osteoplastic replacement of mandibular defects].  


Remote (from 1 to 18 years) results of mandibular defect repair were followed up in 64 patients, to whom auto- and allografts and implants of glass ceramics were implanted. A relatively low incidence of complications in patients with glass ceramic implants demonstrates its advantages over other materials for plastic repair of mandibular defects. PMID:8658577

Makhkamov, E U; Abdullaev, Sh IU



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


Implant-retained mandibular ball-supported and bar-supported overlay dentures are the two most common treatment options for the edentulous mandible. The superior option in terms of strain distribution should be determined. The three-dimensional model of mandible (based on computerized tomography scan) and its overlying implant-retained bar-supported and ball-supported overlay dentures were simulated using SolidWorks, NURBS, and ANSYS Workbench. Loads A (60 N) and B (60 N) were exerted, respectively, in protrusive and laterotrusive motions, on second molar mesial, first molar mesial, and first premolar. The strain distribution patterns were assessed on (1) implant tissue, (2) first implant-bone, and (3) second implant-bone interfaces. Protrusive: Strain was mostly detected in the apical of the fixtures and least in the cervical when bar design was used. On the nonworking side, however, strain was higher in the cervical and lower in the apical compared with the working side implant. Laterotrusive: The strain values were closely similar in the two designs. It seems that both designs are acceptable in terms of stress distribution, although a superior pattern is associated with the application of bar design in protrusive motion. PMID:20712443

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



Removable partial overdentures for the irradiated patient  

SciTech Connect

Patients who have received radiotherapy to the head and neck area must avoid dental extractions and seek simplicity in treatment and home care follow-up. For partially edentulous patients, removable partial overdenture therapy can fulfill these goals while maintaining the high level of function and aesthetics desired by patients.11 references.

Rosenberg, S.W. (New York Univ. School of Dentistry, NY (USA))



A simplified chair-side technique with pre-fabricated directional rings in a case of divergent root retained overdenture.  


Precision attachments have been largely ignored by most dental professionals for trivial reasons such as cost and reluctance of a practitioner to grasp the intricacies of its indications and applications. Precision attachments offer considerable advantages such as increased retention of a denture, preservation of teeth which are otherwise indicated for extraction, as a viable alternative to implant retained overdenture and the ability to obtain parallelism in divergent abutments. A prosthodontist who familiarizes himself with precision attachments will be in a position to suggest a better treatment options in retaining teeth which might otherwise be considered for extraction or immediate implant placement. In this clinical report, we have described an overdenture placed on a previously unfavourable abutment made favourable by placing directional rings to maintain parallelism thus facilitating easy insertion and removal of the prosthesis. PMID:22654355

Dileep Nag, V; Ravindra, P; Thirupathi Reddy, B



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

PubMed Central

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



Paresthesia from an overdenture abutment: report of case.  


A case is reported in which paresthesia of the area supplied by the right mental nerve was associated with alveolar ridge resorption and a failing overdenture abutment. After surgical removal of the overdenture abutment, all signs and symptoms of the paresthesia resolved. PMID:6361097

Dale, R A; Amonett, R




Microsoft Academic Search

The treatment of completely toothless patients using oral implants does not always allow the insertion of adequate number implants to ensure an fixed construction, the reasons ranging from anatomical, or health restrictions to financial limitations. Unfortunately, implant supported overdentures have not gained due popularity in Bulgaria. On one hand there is the psychological barrier of having to take out the

Metodi Abadzhiev



Biomechanical analysis of alveolar bone stress around implants with different thread designs and pitches in the mandibular molar area  

Microsoft Academic Search

Threaded implants have been shown to play an important role in increasing mechanical osseointegration. The aim of this study\\u000a was to determine bone stress distribution when using different types of implant thread pitches and designs. Five 3D finite\\u000a element models were constructed to simulate bone stresses induced in implant bodies with two types of thread form: triangular\\u000a (“Tri” prefix) and

Ting-Hsun Lan; Je-Kang Du; Chin-Yun Pan; Huey-Er Lee; Wei-Hao Chung


Mandibular angloplasty.  


Bulging of the mandibular angle is considered to be unattractive in the Orient since it gives the face a quadrangular and muscular appearance. In spite of its muscular origin, surgery should be aimed toward bony reduction or osteoplasty and supplemental myotomy. An intraoral approach was utilized with an oscillating saw to resect a predetermined segment of bone (mandibular angloplasty). In 2 patients with a prominent bilateral mandibular angle, only the bony angle was resected. The improvement of facial esthetics was subtle, and the acceptance and satisfaction of the patients were very good. A review of the literature is included with comments on the diagnosis and treatment of benign masseteric hypertrophy. PMID:1491548

Kim, H C; Kameyama, T



Magnetic attachment for esthetic management of an overdenture  

Microsoft Academic Search

Magnetic attachments are a popular means of retaining removable overdentures and maxillofacial prostheses.1 When used in anterior regions, these attachments often are not esthetic because the metallic color of the cast coping or attachment can be seen directly or through the denture base. An esthetic magnetic attachment with a composite facing can be fabricated to overcome this problem. (J Prosthet

Yuji Kokubo; Shunji Fukushima



Maxillary reconstruction with bone transport distraction and implants after partial maxillectomy.  


Maxillary and mandibular bone defects can result from injury, congenital defect, or accident, or as a consequence of surgical procedures when treating pathology or defects affecting jaw bones. The glandular odontogenic cyst is an infrequent type of odontogenic cyst that can leave a bony defect after being treated by aggressive surgical means. First described in 1987 by Padayachee and Van Wyk, it is a potentially aggressive entity, having a predisposition to recur when treated conservatively, with only 111 cases having been reported hitherto. Most reports emphasize its clinical, radiographic, and histologic features, including a few considerations on rehabilitation for these patients. The aim of this article is to present the case of a 24-year-old male patient who, in 2001, was diagnosed with a glandular odontogenic cyst and to focus on the surgical approach and rehabilitation scheme. We performed an anterior partial maxillectomy. The osseous defect was treated using bone transport distraction. Dental and occlusal rehabilitation was achieved with titanium implants over transported bone and an implant-supported overdenture. A 9-year follow-up shows no evidence of recurrence of the pathology, adequate shape and amount of bone, functional occlusal and dental rehabilitation, and patient's satisfaction. PMID:23351767

Castro-Núñez, Jaime; González, Marcos Daniel



Telescopic overdenture: Perio-prostho concern for advanced periodontitis  

PubMed Central

The crown- and sleeve-coping denture is a removable prosthesis that is supported by both selectively retained teeth and the residual ridge or mucosa. It is a versatile and successful means of achieving long-term restoration of a partially edentulous jaw. Insertion and removal of the denture and routine oral hygiene are easy to perform. The beneficial results of this form of treatment can be considered for a wide variety of clinical applications for the severely advanced periodontitis case. This paper presents a case report on the prosthetic rehabilitation of a partially edentulous patient with a telescopic overdenture for the mandible and complete denture for the maxilla.

Goswami, Roma; Mahajan, Puneet; Siwach, Amit; Gupta, Ankur



An accelerated clinical chairside technique for casting overdenture attachment copings.  


An accelerated technique for casting a direct-pattern post and core restoration for use in fixed prosthodontics has been previously described. Similar techniques for use in removable prosthodontics show potential for clinical use, specifically for the fabrication of radicular stud overdenture attachments and their corresponding copings. The procedure uses a chairside technique and readily available components to fabricate a direct, acrylic resin pattern combining the elements of a cast coping with a fixed radicular attachment. This pattern can subsequently be invested, cast, finished and polished, luted, and attached to the removable prosthesis in a single clinical appointment. PMID:22024184

Scherer, Michael D; Campagni, Wayne V




Microsoft Academic Search

\\u000a This chapter describes required facilities, preoperative procedures, anesthesia, and operative techniques for the implantation\\u000a of currently available defibrillator models. Electrophysiologists would prefer not to have to think about the days when defibrillator\\u000a implantations were performed using a median sternotomy with mortality rates exceeding five percent. The size reduction of\\u000a the generators and the use of transvenous leads have allowed subcutaneous

Antonio Pacifico; Philip D. Henry


Mandibular bone repair by implantation of rhBMP-2 in a slow release carrier of polylactic acid—An experimental study in rats  

Microsoft Academic Search

The aim of the present study was to test the hypothesis that human recombinant bone morphogenic protein 2 (rhBMP-2) implanted in a slow release carrier of polylactic acid (PLA) can repair a non-healing defect in the rat mandible and maintain the thickness of an augmented volume. p-dl-lactic acid discs were produced and loaded with 48 and 96?g rhBMP-2 and inserted

Henning Schliephake; Herbert A. Weich; Christian Dullin; Rudolf Gruber; Sarah Frahse



Dental rehabilitation using an implant-carrying plate system in a severely resorbed edentulous maxilla: a case report.  


This clinical article describes a case of dental rehabilitation using an implant-carrying plate system (EPITEC) for a patient with severely resorbed edentulous maxilla and microstomia. In this case, the presence of microstomia prevented bone augmentation procedures through an intraoral approach. Treatment using 2 endosseous implants inserted in the canine regions and an implant-supported overdenture was planned. However, endosseous implants were not feasible on the right side because of insufficient available bone volume. An implant-carrying plate system was then utilized on the right side. Four months later, an implant-supported ball-attachment overdenture was fabricated. At the 2-year follow-up, the clinical course remained uneventful, and the patient remained satisfied with the treatment. PMID:18416420

Kurita, Hiroshi; Sakai, Hironori; Uehara, Shinobu; Kurashina, Kenji


Autotransplantation of Mandibular Third Molar: A Case Report  

PubMed Central

Autogenous transplantation is a feasible, fast, and economical option for the treatment of nonsalvageable teeth when a suitable donor tooth is available. This paper presents successful autotransplantation of a mature mandibular left third molar (38) without anatomical variances is used to replace a mandibular left second molar (37). The mandibular second molar was nonrestorable due to extensive root caries and resorption of distal root. After extraction of mandibular second and third molars, root canal therapy was done for the third molar extraorally, and the tooth was reimplanted into the extracted socket of second molar site. After one year, clinical and radiographic examination revealed satisfactory outcome with no signs or symptoms suggestive of pathology. In selected cases, autogenous tooth transplantation, even after complete root formation of the donor tooth, may be considered as a practical treatment alternative to conventional prosthetic rehabilitation or implant treatment.

Ravi kumar, Pabbati; Jyothi, Mandava; Sirisha, Kantheti; Racca, Khushboo; Uma, Chalasani



Transmigration of Mandibular Canines  

PubMed Central

The purpose of this paper is to present the first case of unusual reverse oblique (110 degrees to midsagittal plane) migration of mandibular right canine crossing the jaw midline and piercing the lower border of the mandible at the level of the opposite canine and also to report two more cases of transmigrated mandibular canine and one case of transmigrating mandibular canine. Mandibular canines are “cornerstone” of dental arch; their importance is manifested by their efficiency in masticatory function, stability of dental arch, and aid in maintaining natural facial expression. Early detection of this anomaly can help preserving these canines by orthodontic intervention or by surgical transplantation. This developmental anomaly is properly diagnosed by radiographic evaluation, which is primarily based on the panoramic radiograph. In patients with overretained deciduous canines or missing permanent canines, an intraoral radiograph should be supplemented with panoramic radiograph. This paper discusses the importance of early diagnosis of canine transmigration in treatment planning and reviews the various possible treatment options.

Umashree, N.; Kumar, Avinash; Nagaraj, Tejavathi



Iliac crest flap for mandibular reconstruction after advanced stage mandibular ameloblastoma resection.  


Ablative surgeries for neoplastic processes of the oral cavity, traumas, infections/inflammations, osteoradionecrosis, and congenital deformities are the most common causes of large mandibular defects. Ameloblastoma is a locally aggressive tumor that, if not treated, can gain an enormous size and cause severe facial disfigurement and functional impairment. Although the smaller lesions of ameloblastoma in the mandible are treated by conservative approaches such as marsupialization, enucleation, and curettage combined with liquid nitrogen spray cryosurgery, larger lesions require radical surgical ablation procedures resulting in large tissue defects. A large mandibular defect has deleterious effects on a person's life, with a significant loss in the quality of life unless it is reconstructed successfully. The aim of present case series report is to show the results of the multidisciplinary treatment of patients with advanced stage ameloblastoma, including tumor resection, simultaneous reconstruction with iliac crest flap, followed by placement of endosseous dental implants, and finally the prosthodontic rehabilitation. PMID:21629065

Sönmez, Erhan; Tözüm, Tolga Fikret; Tulunoglu, Ibrahim; Sönmez, Nalan Sule; Safak, Tunc



[The functional mandibular prognathism].  


The functional mandibular prognathism belong to the class III malocclusion according to the terminology of Angle. Its origins are multiple, from the abnormality of eruption of deciduous or definitive incisors to lingual dysfunction (low position of the tongue). In spite of its weak prevalence, it must be prematurely detected and treated (mixed or temporary teeth) to prevent a functional anomaly to become a skeletal anomaly. It is important at this stage to proceed to the unique gesture which allows making the differential diagnosis: it is the De Névrezé procedure; it allows obtaining a more retrusive position of the mandible to minimize the dental relations. In case of true mandibular prognathism, the maneuver does not succeed; there is no modification of the dental reports. An interceptive therapeutic phase allows finding quickly a previous correct guide and to rehabilitate the growth of jaws. PMID:19054656

Le Gall, M; Philip, C; Bandon, D



Occlusal Recording Components for Dental Implant-Supported Prostheses  

PubMed Central

In this article, three techniques for maxillo-mandibular relationship for Replace-Select implants are described. The use of healing abutments, planning abutments, and Impression copings are presented, and the advantages and disadvantages are discussed.

Monzavi, A.; Alikhasi, M.; Taghavi, F.



Occlusal recording components for dental implant-supported prostheses.  


In this article, three techniques for maxillo-mandibular relationship for Replace-Select implants are described. The use of healing abutments, planning abutments, and Impression copings are presented, and the advantages and disadvantages are discussed. PMID:22924105

Monzavi, A; Alikhasi, M; Taghavi, F



The role in masseter muscle activities of functionally elicited periodontal afferents from abutment teeth under overdentures.  


Five overdenture wearers with a small number of remaining natural teeth were selected to evaluate the effect of the afferent input from periodontal mechanoreceptors on masseter activity in man. As a control, a full denture wearer was included. The subjects were instructed to chew a piece of gum, and/or tap their teeth. Surface EmG from the bilateral masseter muscles were recorded and analysed. When functional pressure was applied, during chewing, to the abutment teeth as well as to mucosa through the denture base, masseter activities were encouraged. Following application of anaesthesia to the periodontal membrane of the abutments, masseter activities were reduced. The duration of the silent period (SP) appearing in the EMG burst following tooth tapping was significantly increased with root support compared to mucosal support only. With topical anaesthesia of the periodontal tissues, SP duration decreased significantly. In conclusion, it has become apparent that the pressure sensibility of abutment teeth bearing functional pressure under an overdenture base is capable of facilitating masseter activity, as one of the sources of oral sensory input during mastication. PMID:7028928

Mushimoto, E



Five-year multicenter study of magnetic attachments used for natural overdenture abutments.  


The purpose of this study was to examine a longitudinal clinical performance of magnetic attachments used for natural overdenture abutments. The study included 131 patients who had used removable prostheses (complete overdentures 31%, partial dentures 69%) more than 5 years (40-90 years old) with 211 magnetic attachments on natural abutments (Magfit 400 or 600; Aichi Steel co., Aichi, Japan) treated in 15 clinics using a standardized protocol. Analyses were performed on the degree of patient satisfaction regarding retention, complications of magnets (corrosion, detachment from denture base), abutments (pain during mastication, periodontal pocket formation, inflammation, mobility), and dentures (fracture etc.). Ninety-seven percent of patients were satisfied with the retention and stability of their dentures. No corrosion of magnet was observed, and 19 magnets were detached. Most frequent complication of abutments was periodontal pocket formation (52%), followed by the inflammation (29%), increase in mobility (27%) and pain (4%). Magnetic attachment on natural tooth abutments provided a viable and long-term treatment option. PMID:23356632

Gonda, T; Yang, T C; Maeda, Y



Abberantly placed impacted mandibular canine  

PubMed Central

Pre-eruptive migration of a tooth across the midline is termed as transmigration. It is believed that transmigration is rare and unique to the mandibular permanent canines, and even more rarely reported for others. Transmigration is a phenomenon of yet unknown etiology. It follows the direction of its long axis, with the crown leading the migration. The tendency of a canine to cross the barrier of mandibular midline suture is a more important consideration than the distance of migration after crossing the midline. Here we present one new case of aberrantly positioned right mandibular canine which has undergone migration and was accidently found on radiological examination before orthodontic treatment. Once diagnosed an aberrantly positioned impacted canine requires surgical removal.

Bahl, Rashi; Singla, Jeetinder; Gupta, Mohita; Malhotra, Ankit



A new technique for mandibular osteotomy  

Microsoft Academic Search

Sagittal split osteotomy (SSO) is a surgical technique largely employed for mandibular mobilizations in orthognatic procedures. However, the traditional design of buccal osteotomy, located at the junction of mandibular ramus and body, may prevent more extensive sliding between the bone segments, particularly on the advance, laterality and verticality of the mandibular body. The author proposes a new technical and conceptual

Edela Puricelli



Mandibular osteotomies in orthognathic surgery.  


Bilateral sagittal split osteotomy is the most commonly used osteotomy of the mandible in orthognathic surgery. The authors describe their experience in evaluating the orthognathic patient with a mandibular deformity. The bilateral sagittal split osteotomy surgical technique used by the authors is reviewed along with postoperative management. PMID:17667689

Orloff, George; Hale, L T C Robert



Surgical repair of a mandibular bony defect following the removal of an amelobalstoma  

PubMed Central

This case report describes a 35-year-old Caucasian radiographer who presented with a significant mandibular bony defect following multiple excisions of an ameloblastoma. As a result, there was an absence of teeth on the lower-right mandible and a clear defect in the mandible. The treatment objectives were to rebuild the mandibular defect, with a long-term view of inserting dental implants. In a novel approach outlined in this presentation, tissue expansion of the submucosa, a titanium construct and an iliac bone graft were used to rebuild the patient’s jaw. This surgical technique is recommended for the reconstruction of bony defects.

Ejiofor, Kandi



Vertical splitting of the mandibular body as an alternative to inferior alveolar nerve lateralization.  


The aim of this study was to present and evaluate a modified technique to inferior alveolar nerve lateralization (IANL) that allows the placement of longer implants in the posterior mandibular region. One hundred and forty-three consecutive patients were enrolled in this study; these patients had between 1.8 and 8mm residual crestal height above the mandibular canal. Vertical splitting of the mandibular body was performed using piezoelectric surgery followed by bone expansion and insertion of special conical implants of 10 and/or 12mm in length. Two hundred and sixty-nine osteotomies were performed and 636 implants were inserted, with a survival rate of 99% at the end of 12 months. Immediately postoperative there was an alteration of sensation in the lip/chin area in 8.5% of cases; 4.1% regained full sensation within 10-14 days, 2.6% after 8 weeks, and 0.7% had persistent paresthesia that did not affect their daily activities. Progressively increasing pain and numbness was present in 1.1%; the implants were removed 6 months postoperatively. This is a relatively simple procedure that has no limitations in clinical situations with minimal bone height. It allows for greater implant stability, and the risk of neurological disturbance is minimal. PMID:23769148

Rodriguez, J G; Eldibany, R M



Mandibular reconstruction using stereolithographic 3-dimensional printing modeling technology.  


Mandibular reconstruction can be challenging for the surgeon wishing to restore its unique geometry. Reconstruction can be achieved with titanium bone plates followed by autogenous bone grafting. Incorporation of the bone graft into the mandible provides continuity and strength required for proper esthetics and function and permitting dental implant rehabilitation at a later stage. Precious time in the operating room is invested in plate contouring to reconstruct the mandible. Rapid prototyping technologies can construct physical models from computer-aided design via 3-dimensional (3D) printers. A prefabricated 3D model is achieved, which assists in accurate contouring of plates and/or planning of bone graft harvest geometry before surgery. The 2 most commonly used rapid prototyping technologies are stereolithography and 3D printing (3DP). Three-dimensional printing is advantageous to stereolithography for better accuracy, quicker printing time, and lower cost. We present 3 clinical cases based on 3DP modeling technology. Models were fabricated before the resection of mandibular ameloblastoma and were used to prepare bridging plates before the first stage of reconstruction. In 1 case, another model was fabricated and used as a template for iliac crest bone graft in the second stage of reconstruction. The 3DP technology provided a precise, fast, and cheap mandibular reconstruction, which aids in shortened operation time (and therefore decreased exposure time to general anesthesia, decreased blood loss, and shorter wound exposure time) and easier surgical procedure. PMID:19716728

Cohen, Adir; Laviv, Amir; Berman, Phillip; Nashef, Rizan; Abu-Tair, Jawad



Relevance of anterior mandibular body ostectomy in mandibular prognathism  

PubMed Central

Purpose: We tried to find out the relevance of anterior mandibular body ostectomy in deformities of the mandible specially prognathism, which is primarily limited to anterior part only. Patients and Methods: Ten patients with skeletal deformity along with malocclusion, which was limited to anterior body of mandible were selected. Selected patients had proper molar interdigitation (even if class 3) and in general had anterior crossbite (except one). All patients had crossed their growth spurts and had no hormonal influence on facial deformity. Specific protocol, including cephelometric analysis cephalometry for orthognathic surgery, prediction tracing and model surgeries were devised. Pre and post-surgical orthodontics and body ostectomy were performed in all patients along with 18-month post-op follow-up. Results: There was significant reduction in prognathism and horizontal dysplasia in all ten patients. Anterior crossbite as well as axis of incisiors over mandibular plane was corrected in all patients due to decrease in length of mandibular body. All patients showed decreased facial height and better lip competence with intact posterior occlusion and no (negligible or transient) sensory loss. Conclusions: Our study could confirm that people whose deformity is limited to the anterior part of mandible with reasonable occlusion posteriorly can get satisfactory cosmetic and functional results through body ostectomy alone rather than going for surgical procedure in the ramal area, which is liable to cause sensory and occlusal disturbances.

Bansal, Pankaj; Singh, Virender; Anand, S. C.; Bansal, Sumidha



Pearls of Mandibular Trauma Management  

PubMed Central

Mandibular trauma is a common problem seen by plastic surgeons. When fractures occur, they have the ability to affect the patient's occlusion significantly, cause infection, and lead to considerable pain. Interventions to prevent these sequelae require either closed or open forms of reduction and fixation. Physicians determining how to manage these injuries should take into consideration the nature of the injury, background information regarding the patient's health, and the patient's comorbidities. Whereas general principles guide the management of the majority of injuries, special consideration must be paid to the edentulous patient, complex and comminuted fractures, and pediatric patients. These topics are discussed in this article, with a special emphasis on pearls of mandibular trauma management.

Koshy, John C.; Feldman, Evan M.; Chike-Obi, Chuma J.; Bullocks, Jamal M.



[Mandibular reconstruction by a free peroneal transfer].  


After an anatomical study of the osteo-septo-cutaneous fibular flap, we reported 4 reconstructions of segmental mandible defects by this procedure, published in 1989 by D. Hidalgo. 2 patients presented mandibular defects associated with intraoral soft- tissue loss, following resection for epidermoid carcinoma with pre or post-operative radiation. The third patient had a multirecurrent ameloblastoma associated with extraoral soft-tissue extension. The fourth patient presented a complex loss of soft tissue and mandible following a war injury. The flaps survived in all patients. The osteo-septo-cutaneous fibular flap for mandible reconstruction has presented several advantages. The flap has been elevated under a tourniquet, the distant donor site has allowed a two-team approach. The osteo-septo-cutaneous blood supply has been adequate to support a skin island for intra or extraoral soft-tissue replacement. Biomechanical properties of the fibula have allowed fixation with miniplates and no postoperative intermaxillary fixation. Osteointegrated implants (Branemark) for dental rehabilitation were done for one patient. There was no long-term donor-site morbidity. PMID:1626196

Menard, P; Germain, M A; Kapron, A M; Foussadier, F; Schwabb, G; Bertrand, J C



Mandibular nerve entrapment in the infratemporal fossa  

Microsoft Academic Search

The posterior trunk of the mandibular nerve (V3) comprises of three main branches. Various anatomic structures may entrap and potentially compress the mandibular nerve branches.\\u000a A usual position of mandibular nerve (MN) compression is the infratemporal fossa (ITF) which is one of the most difficult\\u000a regions of the skull base to access surgically. The anatomical positions of compression are: the

Maria N. PiagkouT; T. Demesticha; G. Piagkos; G. Androutsos; P. Skandalakis



A clinical and histological evaluation of titanium mini-implants as anchors for orthodontic intrusion in the beagle dog  

Microsoft Academic Search

The aim of this study was to determine the anchorage potential of the titanium mini-implant for orthodontic intrusion of the mandibular posterior teeth. Six mini-implants were surgically placed around the mandibular third premolars on each side in 3 adult male beagle dogs. On the buccal site, three mini-implants were placed distal to the apex of the distal root of the

Masami Ohmae; Shigeru Saito; Tomio Morohashi; Kenji Seki; Hong Qu; Ryuzo Kanomi; Ken-ichi Yamasaki; Tomohiro Okano; Shoji Yamada; Yoshinobu Shibasaki DDS



Endosseous titanium implants as anchors for mesiodistal tooth movement in the beagle dog  

Microsoft Academic Search

The purpose of this study was to determine the anchorage potential of titanium implants (Brånemark; 3.75 × 7 mm) with the use of a sectional arch wire technique for orthodontic mesiodistal tooth movement, as assessed by the osseointegration of implants and tooth movement. Two implants were surgically placed in healed mandibular extraction sites of the second and third premolars on

Shigeru Saito; Naoko Sugimoto; Tomio Morohashi; Masahiko Ozeki; Hitomi Kurabayashi; Hiroshi Shimizu; Ken-ichi Yamasaki; Akihiko Shiba; Shoji Yamada; Yoshinobu Shibasaki



Cochlear Implants  


... Medical Devices Products and Medical Procedures Implants and Prosthetics - Section Contents Menu Products and Medical Procedures Implants and Prosthetics Cochlear Implants What is a Cochlear Implant? Benefits ...


Complex mandibular reconstruction after a partial mandibulectomy with a fibula free graft: A clinical report.  


This report describes the surgical and prosthetic reconstruction of a partial mandibular resection due to an osteomyelitic variant with a free fibula microvascular graft, dental implant placement, and reconstruction with a computer-aided design/computer-aided manufacturing (CAD/CAM) partial fixed dental prosthesis. A team composed of a prosthodontist, oral and maxillofacial surgeon, and otolaryngologist was required to treat and restore the patient to near normal comfort and function. PMID:24029611

Schneider, Robert; Fridrich, Kirk; Funk, Gerry



Mandibular coronoid fractures: treatment options.  


Fractures of the coronoid process are uncommon and can easily be missed. The purpose of this study was to classify the fracture patterns and explore the treatment options. This retrospective study included 39 patients with fractures of the mandibular coronoid process. Treatment protocols were developed based on the time of fracture, degree of mouth opening, location of the coronoid fracture, types of fracture, and other concomitant fractures. All patients were followed up for 12-60 months. Sixteen patients underwent conservative management and four of these patients developed progressive trismus, which improved significantly after removal of the coronoid process. Twenty-three patients underwent open reduction and internal fixation (ORIF) via the modified retromandibular approach. Follow-up data showed significant improvement in maximum mouth opening and symptoms (diet and pain) compared to their preoperative status. In summary, conservative management is first recommended for fractures of the coronoid process with minimal displacement or restriction of mouth opening. For patients with significant fracture displacement and limited mouth opening, or with concomitant fractures of the zygoma, zygomatic arch, or mandibular ramus, ORIF via the modified retromandibular approach through the anterior border of the parotid gland is an alternative treatment method. PMID:23602277

Shen, L; Li, J; Li, P; Long, J; Tian, W; Tang, W



Oral rehabilitation of a patient with bruxism and cluster implant failures in the edentulous maxilla: a clinical report.  


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

Lin, Wei-Shao; Ercoli, Carlo; Lowenguth, Roxanne; Yerke, Lisa M; Morton, Dean



Mandibular symphyseal distraction osteogenesis--simplified.  


The limb lengthening technique of distraction osteogenesis (DO) used in orthopedic surgery is a well established procedure. DO has been adapted to the facial skeleton to change the anterior-posterior position of the jaws. Historically, the mandibular arch transverse dimension has been considered immutable. Mandibular arch expansion is done with a variety of methods including Schwarz plates, lingual arches, functional appliances and arch wires; these methods produce limited dimensional change with questionable long-term stability. Adapting the Ilizarov treatment protocol to the mandibular symphysis can produce a regenerate bone thereby adding dimension to the innate basal bone. This can then be used to produce a potentially greater effect than the conventional modes of mandibular expansion. The modified mandibular symphyseal distraction device used by the authors is a tooth borne device fabricated with a Schwartz screw and self cured acrylic resin coverage over all the erupted mandibular teeth. The appliance used by the authors has been found to be very economical, easy to fabricate and clinically efficient. The surgical approach used, requiring surgery under local anesthesia in the outpatient department obviates need of hospital admission and the cost and time factors associated with in-patient therapy Mandibular Symphyseal Distraction Osteogenesis (MSDO) with this innovative low cost approach may be compared in a multi centric study with other established methods of MSDO. PMID:23941027

Chopra, S S; Sahoo, Nanda Kishore; Jayan, Balakrishna



Mandibular first molar with three distal canals  

PubMed Central

With the increasing number of reports of aberrant root canal morphology, the clinician needs to be aware of the variable anatomy. Various case reports have been published with the finding of middle mesial canal in mandibular first molar, however finding of middle distal canal in distal root of mandibular first molar is rare. This case report describes root canal treatment of two rooted mandibular first molar with five root canals (three in distal and two in mesial root), and Sert and Bayirli Type XVIII canal configuration in distal root.

Jain, Shweta



Dental Implants  


Dental Implants Did you know that dental implants are frequently the best treatment option for replacing missing teeth? ... implants can last a lifetime. Anatomy of a Dental Implant A dental implant designed to replace a single ...


Mandibular reconstruction with autologous human bone marrow stem cells and autogenous bone graft in a patient with plexiform ameloblastoma.  


Ameloblastoma is a histologically benign tumor, but it shows a tendency of locally aggressive behavior. To our knowledge, this is the first report of a successful reconstruction performed for treating a mandibular defect by using autologous human bone marrow mesenchymal stem cells in a patient with plexiform ameloblastoma. In this article, we report the result of the mandibular reconstruction with autologous human bone marrow mesenchymal stem cells and autogenous bone graft, followed by the placement of osteointegrated dental implant and prosthodontic treatment in a patient with plexiform ameloblastoma. PMID:23851884

Kim, Bong Chul; Yoon, Jung-Hoon; Choi, Boyoung; Lee, Jun



Evaluation of bifid mandibular canals with cone-beam computed tomography in a Turkish adult population: a retrospective study  

Microsoft Academic Search

Purpose  Knowing the anatomic location and also variations of the mandibular canal is especially important for surgical procedures\\u000a on mandible such as dental implant surgery, impacted molar extraction and sagittal split ramus osteotomy. The purpose of this\\u000a study was to clarify the incidence and location of bifid mandibular canals in an adult Turkish population to avoid complications\\u000a during surgical procedures.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A

Kaan Orhan; Seçil Aksoy; Burak Bilecenoglu; Bayram Ufuk Sakul; Candan Semra Paksoy


Bone marrow aspirate concentrate used with bovine bone mineral to reconstruct vertical and horizontal mandibular defects: report of two techniques.  


Purpose: Following initial positive reports of the use of bone marrow aspirate concentrate (BMAC) in combination with bovine bone mineral (BBM) in augmentation procedures, the technique was evaluated in patients with mandibular deficiency. Materials and Methods: Two adult patients required surgical correction of a deficient alveolar ridge (one patient showed horizontal deficiency only, and the other patient presented with horizontal and vertical deficiency) prior to dental implant placement. In both patients, the reconstruction was performed with BBM in combination with mononuclear cells concentrated by the BMAC method using different techniques. Results: The patients recovered well from all surgical procedures. Histologically, there was uniform bone formation, which allowed placement of dental implants. Conclusion: The results suggest that the use of BMAC in combination with BBM, without autogenous bone, has the potential to restore horizontal and vertical mandibular alveolar defects, providing a functional bone structure and allowing dental implant placement for subsequent prosthetic rehabilitation. PMID:24066349

Sauerbier, Sebastian; Giessenhagen, Bernd; Gutwerk, Wolfgang; Rauch, Petra; Xavier, Samuel P; Oshima, Toshiyuky; Nagursky, Heiner; Gutwald, Ralf; Schmelzeisen, Rainer


Treatment of recurrent mandibular ameloblastoma  

PubMed Central

Ameloblastoma is a locally invasive benign odontogenic tumor with a high rate of recurrence in the long term. The authors conducted a retrospective study of patients with mandibular ameloblastoma in order to evaluate recurrent ameloblastoma management. The study included data from 31 patients over a period of 10 years. Data collected included age, gender, tumor location, histological findings, initial treatment, number of recurrences and year of onset, type of treatment of recurrence, reconstruction and follow-up. Recurrences were detected in nine patients (29%). Tumor recurrences appeared at 32 months on average following the initial surgical procedure. Recurrences were associated mainly to inadequate initial therapeutic approach and were treated by bone resection with a safety margin of at least 1 cm beyond the radiographically visible margins. Immediate reconstruction of bone defects was performed with grafts or free flaps.




Treatment of a Class II Division 2 malocclusion with space reopening for a single-tooth implant  

Microsoft Academic Search

This case report describes the treatment of an adolescent girl with a skeletal Class II Division 2 malocclusion and impinging overbite. One of 2 previously extracted premolars had to be replaced by a single-tooth implant after adequate space reopening. An optimal overbite-overjet relationship was achieved through significant intrusion and proclination of maxillary and mandibular incisors. A horizontally impacted mandibular second

Roy Sabri



Problems with dental implants that were placed on vertically distracted fibular free flaps after resection: A report of six cases  

Microsoft Academic Search

We report the clinical outcome of dental implants placed on vertically distracted fibular free flaps that were used to reconstruct maxillary and mandibular defects after resection. Distraction osteogenesis (DO) of fibular free flaps was used for six patients (5 men, 1 woman) a mean of 19 months (range 11–38) after 5 mandibular and 1 maxillary reconstructions. A mean of 5

Giuseppe Lizio; Giuseppe Corinaldesi; Francesco Pieri; Claudio Marchetti



Classification and treatment of prominent mandibular angle.  


In Oriental culture, the contour of the mandibular angle is important for feminine facial shape because a woman who has a wide and square face is thought to have had an unhappy life. A prominent mandibular angle, which does not coincide with the natural look, produces a characteristic quadrangle, coarse, and muscular appearance. So Oriental women who have a prominent mandibular angle want to have an ovoid, reduced, and slender face by aesthetic mandibular angle resection. Many satisfactory corrections of a prominent mandibular angle by various operative techniques have been reported. But reasonable morphologic classification and treatment were not reported. So we classified prominent mandibular angles into four groups by morphology and operated on the patients according to their classification with different modalities: no square shape but only a reduced gonial angle in the profile view-class I, mild form; severe mandibular angle protrusion with lateral protrusion-class II, moderate form; a definite square-shaped angle (class II) with masseteric hypertrophy-class III, severe form; and combined prominent mandibular angle and chin deformity-class IV, complex form. We use angle ostectomy through the intraoral route alone or with an additional external stab incision for class I. An external stab incision to set up the reciprocating saw is sometimes helpful in class I cases because there is no lateral protrusion of the angle. For class II cases, we use conventional intraoral angle ostectomy only or angle splitting ostectomy with contouring. For class III cases, we use angle splitting ostectomy and contouring with partial masseteric myectomy. In class IV, we use angle ostectomy and additional genioplasty. During 7 years, we have performed 46 cases of mandibular angle resection. Of the mandibular angle resection cases, 19 were class I, 15 were class II, 9 were class III, and 3 were class IV. A total of 42 patients were satisfied with the postoperative results. For reasonable and satisfactory final results, classification according to the mandibular angle shape and suitable treatment according to the classification are essential. PMID:11692255

Kim, S K; Han, J J; Kim, J T


Canal complexity of a mandibular first molar  

PubMed Central

The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and technically challenging. This case report presents the treatment of a mandibular first molar with five root canals, of which three were located in the mesial root. A third canal was found between the mesiobuccal and mesiolingual root canals. The morphological pattern of separate apical terminations of three mesial root canals with separate orifices, as manifested in this case, is a rare one.

Poorni, S; Kumar, RA; Indira, R



Isolated osteochondroma near the mandibular angle.  


A benign tumour of osseous and cartilaginous origins, osteochondroma generally develops in osseous tissue and is frequently found near the end of long bones. It is relatively rare in the oral and maxillofacial region but is common in the mandibular condyle and coronoid process in the pediculate form. This is a report on a rare case of osteochondroma in soft tissue near the mandibular angle without pedicle to the bone. PMID:17052896

Sakai, H; Minemura, T; Ito, N; Miyazawa, H; Kurashina, K



Classification and Treatment of Prominent Mandibular Angle  

Microsoft Academic Search

.   In Oriental culture, the contour of the mandibular angle is important for feminine facial shape because a woman who has a\\u000a wide and square face is thought to have had an unhappy life. A prominent mandibular angle, which does not coincide with the\\u000a natural look, produces a characteristic quadrangle, coarse, and muscular appearance. So Oriental women who have a

Seok Kwun Kim; Jae Jung Han; Jeong Tae Kim



Mandibular symphysis of large-bodied hominoids.  


The hominoid mandibular symphysis has received a great deal of attention from anatomists, human biologists, and paleontologists. Much of this research has focused on functional interpretations of symphyseal shape variation. Here, we examine the two-dimensional cross-sectional shape of the adult mandibular symphysis for 45 humans, 42 chimpanzees, 37 gorillas, and 51 orangutans using eigenshape analysis, an outline-based morphometric approach. Our results demonstrate that a large proportion of the variation described by the first eigenshape correlates with proposed functional adaptations to counteract stresses at the mandibular midline during mastication. Subsequent eigenshapes describe subtle aspects of shape variation in the mandibular symphysis. The morphology associated with these eigenshapes does not conform with functional predictions, nor does it show a relationship with sexual dimorphism. However, eigenshapes provide for considerable taxonomic discrimination between the four taxa studied and may consequently prove useful in the analysis of fossil material. Comparison with elliptical Fourier analysis of the mandibular symphysis identifies eigenshape analysis as providing superior taxonomic discrimination. The results presented here demonstrate that the cross-sectional shape of the mandibular symphysis results from a complex interplay of functional and nonfunctional influences and for the first time identifies and quantifies the specific aspects of variation attributable to these factors. PMID:16715835

Sherwood, Richard J; Hlusko, Leslea J; Duren, Dana L; Emch, Victoria C; Walker, Alan



Immediate placement of dental implants in the mandible  

PubMed Central

This case describes extraction of teeth in the mandibular arch, i.e., 41 42 43 44 45 51 52 53 54 55 56 57 58 (grade two mobility), followed by immediate placement of four dental implants (3i biomet), two in the 45 55 region and two dental implants in 12 21 region. A prefabricated provisional mandibular denture was immediately placed. The purpose of immediate placement was to aid the patient resume his professional duties the next day itself along with esthetic and functional comfort, psychological well-being and most importantly preserving the remaining tissue in a healthy condition.

Puttaraju, Gurkar Haraswarupa; Visveswariah, Paranjyothi Magadi



Facial nerve paralysis and frey syndrome in an infant following removal of an internal mandibular distraction device.  


Mandibular distraction using an implantable device has become a widely accepted and utilized procedure for the treatment of retrognathia. Although excellent results have been reported and observed with distraction osteogenesis, complications such as facial nerve injury have been previously reported. Often, this injury is usually temporary and corrects over the course of time. Frey syndrome has been classically described as an injury or severance of the auricotemporal branch of the trigeminal nerve. It is commonly seen as a complication of parotid surgery and has never been reported in association with mandibular distraction. The authors report a unique case of both facial nerve paralysis and Frey syndrome in a patient following the removal of an internal mandibular distraction device. A review of the literature along with diagnosis and management are discussed. PMID:23714921

Kapadia, Sameer Mehbub; Golinko, Michael Samuel; Williams, Joseph Kerwin



Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts ® total joint prostheses  

Microsoft Academic Search

The purpose of this study was to evaluate soft tissue response to maxillo-mandibular counter-clockwise rotation, with TMJ reconstruction and mandibular advancement using TMJ Concepts® total joint prostheses, and maxillary osteotomies in 44 females. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford). Eighteen patients had genioplasties with either porous block hydroxyapatite or hard

K. E. D. Coleta; L. M. Wolford; J. R. Gonçalves; A. dos Santos Pinto; D. S. Cassano; D. A. G. Gonçalves



Pain caused by a dental implant impinging on an accessory inferior alveolar canal: a case report.  


This report presents a case history of intractable facial pain following the placement of a posterior mandibular implant. The pain was resistant to all medical management, but a cone beam computed tomography (CBCT) scan showed that the implant impinged on an unusual accessory inferior alveolar nerve. The decision to remove the implant led to significant pain reduction. This clinical example underscores the need for scrupulous imaging prior to implant placement. PMID:23476904

Maqbool, Arman; Sultan, Ahmed Ali; Bottini, Gian Battista; Hopper, Colin


Five-year results of fixed implant-supported rehabilitations with distal cantilevers for the edentulous mandible  

Microsoft Academic Search

OBJECTIVES: The purpose of this study was to evaluate the survival rate, success rate and primary complications associated with mandibular fixed implant-supported rehabilitations with distal cantilevers over 5 years of function. MATERIAL AND METHODS: In this prospective multi-center trial, 45 fully edentulous patients were treated with implant-supported mandibular hybrid prostheses with distal extension cantilevers. Data were collected at numerous time

German O. Gallucci; Camden B. Doughtie; Jae Woong Hwang; Joseph P. Fiorellini; Hans-Peter Weber



In vivo evaluation of resorbable bone graft substitutes in mandibular sockets of the beagle.  


Hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)), with its high biocompatibility and good bioaffinity, stimulates osteoconduction and is slowly replaced by the host bone after implantation. However, clinical use of HA as a bone substitute has proved problematic. It is difficult to prevent dispersion of the HA granules and to mold the granules into the desired shape. Calcium sulfate as a bone graft substitute is rapidly resorbed in vivo releasing calcium ions, but fails to provide a long-term, three-dimensional framework to support osteoconduction. The setting properties of calcium sulfate, however, allow it to be applied in a slurry form, making it easier to handle and apply in different situations. This study examines the in vivo response of a (Hydroxyapatite, apatitic phase)/calcium sulfate dehydrate (CSD) composite using different ratios in the mandibular premolar sockets of the beagle. The HA (AP)/CSD composite materials prepared in ratios of 30/70, 50/50, and 70/30 were implanted into the mandibular premolar sockets for 5 and 10 weeks. The control socket was empty. The authors compared the radiographic properties and the changes in height and width of the mandibular premolar sockets in the beagle. The composite graft in the 30/70 ratio had the best ability to form new bones. PMID:22623380

Shih, Tsai-Chin; Chang, Wei-Jen; Yang, Jen-Chang; Feng, Sheng-Wei; Lin, Che-Tong; Teng, Nai-Chia



Hypohidrotic ectodermal dysplasia with bilateral impacted teeth at the coronoid process: a case rehabilitated with mini dental implants.  


Bilateral migration of teeth into the coronoid process in a patient with ectodermal dysplasia has not been reported in the literature except one report in which severe hypodontia and bilaterally ectopic impacted teeth in the coronoid processes of a nonsyndromic patient occurred. This article presents a 15-year-old female with hypohidrotic ectodermal dysplasia who had surgical removal of bilaterally impacted teeth in the coronoid process and was rehabilitated with a dental implant-retained fixed prosthesis in the mandible and over-denture in the maxilla. PMID:15829868

Güler, Nurhan; Cildir, Sule; Iseri, Ufuk; Sandalli, Nuket; Dilek, Ozkan



Pathological mandibular fractures: a review of the literature of the last two decades.  


Pathological mandibular fractures are rare, accounting for fewer than 2% of all fractures of the mandible. They could be defined as fractures that occur in regions where bone has been weakened by an underlying pathological process. Pathological fractures usually may follow surgical interventions such as third molar removal or implant placement, result from regions of osteomyelitis, osteoradionecrosis, and bisphosphonate-related osteonecrosis of the jaw, occur because of idiopathic reasons or be facilitated by cystic lesions, benign, malignant, or metastatic tumors. Pathological mandibular fractures may be challenging to treat because of their different etiology and peculiar local and general conditions, often requiring a more rigid fixation. In patients with poor medical conditions, simpler and more limited options may be preferred. PMID:23294978

Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Berrone, Sid



21 CFR 872.3960 - Mandibular condyle prosthesis.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3960 Mandibular condyle prosthesis. (a) Identification. A mandibular condyle prosthesis...



Biomechanical finite element analysis of small diameter and short dental implants: extensive study of commercial implants.  


In recent years, mini and short dental implants have become increasingly popular as treatment alternatives for patients in whom the bone is unsuitable for a standard implant. As yet, no detailed scientific analysis of the mechanical and biomechanical impact of the reduced diameter and length of these implants has been published. We analysed 21 commercially available implants (13 mini, eight short) with respect to material behaviour and load transfer to the alveolar bone, using finite element (FE) analysis. Following ?CT scanning and geometry reconstruction, FE models of mini implants and short implants were inserted into idealised bone segments. Mini implants were analysed in the anterior mandibular jaw region at a force of 150 N under immediate loading, using a contact analysis in the FE software package Marc Mentat 2007. Short implants were inserted in posterior bone segments and analysed in the osseointegrated state at an occlusal force of 300 N. Von Mises stresses (up to 1150 MPa) in mini implants partly exceeded the ultimate strength. Implant diameter and geometry had a pronounced effect on stresses in the cortical plate (up to 266 MPa). Strains in spongy bone and stresses in cortical bone around short implants were markedly increased compared to those in standard implants. An increased risk of bone damage or implant failure may be assumed in critical clinical situations. PMID:23092989

Bourauel, Christoph; Aitlahrach, Maria; Heinemann, Friedhelm; Hasan, Istabrak



Original sagittal split osteotomy revisited for mandibular distraction  

Microsoft Academic Search

Introduction: A malformed mandible and an abnormally positioned mandibular foramen make it difficult to plan an ideal osteotomy line for mandibular distraction. In addition, there have been reports of such complications as nonunion, damage and stretch injury of the inferior alveolar nerve and tooth germ damage when conventional osteotomy or corticotomy are used for mandibular distraction. The authors utilized the

Jin-Young Choi; Kyung-Gyun Hwang; Seung-Hak Baek; Jong-Ho Lee; Tae-Woo Kim; Myung-Jin Kim; Young-II Chang



Correlation between planned prosthetic and residual bone trajectories in dental implants  

Microsoft Academic Search

Statement of problem. The success of dental implant treatment relies on a well-developed treatment plan approach. Historically, implant placement was guided mainly by residual bone height and width, at times compromising prosthetic needs. Purpose. This study analyzed the amount of deviation between planned prosthetic trajectory and residual bone trajectory in different areas of the maxillary and mandibular dental arches, by

Dov M. Almog; Rodolfo Sanchez



Guided Bone Regeneration Around Commercially Pure Titanium and Hydroxyapatite-Coated Dental Implants.  

National Technical Information Service (NTIS)

In a split-mouth design, 6 implants were placed in edentulous mandibular ridges of 10 mongrel dogs after preparation of 6 cylindrical mid-crestal defects, 5 mm in depth and 10 mm in diameter. An implant site was then prepared in the center of each defect ...

W. C. Stentz



An electronic device for accelerating bone formation in tissues surrounding a dental implant  

Microsoft Academic Search

A dental implant is a unique structure which can be used with a noninvasive method because it is inserted into the bone in part and extended extracorporally. This study presents an electronic device that is temporarily connected with the dental implant, and reports its effect on accelerating bone formation in the surrounding tissues in a canine mandibular model. A small

Jong K. Song; Tae H. Cho; Hui Pan; Yoon M. Song; In S. Kim; Tae H. Lee; Soon J. Hwang; Sung J. Kim



Nickel-titanium mandibular bonded lingual 3-3 retainer: For permanent retention and solving relapse of mandibular anterior crowding  

Microsoft Academic Search

An innovative technique that involves a nickel-titanium mandibular bonded lingual 3-3 retainer was used to treat relapse of mandibular anterior crowding. The purpose of this study was to demonstrate clinical procedures and to study the effects of a new mandibular bonded lingual 3-3 retainer on the mandibular dental arch. In 18 patients, changes in the irregularity index and in arch

Eric J. W. Liou; Louise I. J. Chen; C. Shing Huang



Unilateral trifid mandibular condyle: a case report.  


Trifid mandibular condyle is an exceptionally rare entity, diagnosed accidentally on radiographic examination. Its etiology is controversial. Dental professionals should have knowledge of this anatomic abnormality and of the problems caused by it in normal function, as well as appropriate treatment modalities. In the literature, only three such cases have been reported. The current case report (the fourth reported) is of a unilateral trifid condyle reported in a 37-year-old woman seeking treatment for a missing tooth. A panoramic radiograph accidentally revealed a discrete modification of the right mandibular condyle. Computed tomography (CT) with 3-D construction was done to confirm the diagnosis. PMID:21370772

Warhekar, Ashish M; Wanjari, Panjab V; Phulambrikar, Tushar



Multiple Mandibular Exostoses: A Rare Case Report  

PubMed Central

Multiple maxillary and mandibular exostoses are common localized overgrowths of the bone. They are non-neoplastic and are thought to be reactive or developmental in origin. These exostoses need to be accurately distinguished from the other more diagnostically significant lesions, notably from the exosteal osteomas. The aetiology of exostosis has been investigated by different authors, but no consensus has been reached so far. We are reporting a rare case of an otherwise healthy 38 year old female with multiple exostoses in the mandibular anterior region, which correlated both clinically and radiographically.

Bansal, Mansi; Rastogi, Sanjay; Sharma, Anamika



CAD/CAM and rapid prototyped titanium for reconstruction of ramus defect and condylar fracture caused by mandibular reduction.  


Fracture or defect of the mandible is a serious complication of mandibular angleplasty, and precise reconstruction for such defect is still a huge challenge. This case report provides a new method based on CAD/CAM and rapid prototyped titanium for individual design, fabrication, and implantation of a mandibular ramus and angle. A 25-year-old woman with a square-shaped face, who had undergone mandibular outer cortex split ostectomy (MOCSO) 3 months earlier, was afflicted by a series of symptoms: asymmetric face, collapse of the right face, masticatory problems, deviation during mouth opening, malocclusion, and TMJ clicks. These symptoms were caused by unintentional removal of the fractured ramus during MOCSO. By means of CT scan data, rapid prototyping, reverse engineering, 3D display, and CAD/CAM, the individualized titanium implant was designed and fabricated. The 3D demo system of operative scheme demonstrated the operative procedure, and determined the position of the implant so as to obtain a perfect fit. Postoperatively, the patient regained satisfactory morphologic symmetry, facial appearance, occlusion, and TMJ functions. PMID:22676828

Wang, Guosong; Li, Jihua; Khadka, Ashish; Hsu, Yuchun; Li, Wenyang; Hu, Jing



Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts ® total joint prostheses  

Microsoft Academic Search

The purpose of this study was to evaluate the anatomical changes and stability of the oropharyngeal airway and head posture following TMJ reconstruction and mandibular advancement with TMJ Concepts custom-made total joint prostheses and maxillary osteotomies with counter-clockwise rotation of the maxillo-mandibular complex. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford). The

K. E. D. Coleta; L. M. Wolford; J. R. Gonçalves; A. dos Santos Pinto; D. S. Cassano; D. A. G. Gonçalves



Mandibular dimensional changes and skeletal maturity  

PubMed Central

Aim: Growth and development of the human face provides a fascinating interplay of form and function. Among the various facial bones, the mandible plays a very important role during various growth-modification therapies. These treatment modalities will yield a better result in less time if properly correlated with skeletal maturity. It is very essential to know where the site of growth occurs and also the time when it occurs or ceases to occur. This study was conducted to assess the mandibular dimensions at various stages of skeletal maturation. Materials and Methods: The subjects included 6 to 18-year-old children who were grouped according to their middle phalanx of the third finger stages of skeletal maturity. Lateral cephalographs were taken and, from their cephalometric tracings, linear and angular measurements of the mandible were made. The values obtained were subjected to statistical analysis. Results: Results showed that the mandibular height, length and symphysis thickness increased with skeletal maturity. An increase in angles SNB (Sella, Nasion, Supramentale) and L1-MP (Long axis lower incisors- Mandibular plane) and a decrease in the gonial angle and ANB (Subspinale, Nasion, Supramentale) angle were observed. Conclusion: The study showed a significant correlation between mandibular growth and skeletal maturity.

Subramaniam, Priya; Naidu, Premila



Incomplete transposition of a mandibular premolar  

Microsoft Academic Search

A case is presented which demonstrates the incomplete transposition of a posterior tooth. In this case, the path of eruption of an abnormally angulated developing mandibular second premolar was diverted distally following the extraction of the adjacent first permanent molar. J. he transposition of teeth is a rare occurrence which has been defined as the interchange of tooth position.1 Most

Mark D. Siegal; Howard L. Needleman


Mandibular advancement devices and seep disordered breathing  

Microsoft Academic Search

It has been nearly 90 years since a dentist first fabricated a dental appliance for a patient with snoring. Since then, mandibular advancement devices or MADs have become a common treatment for obstructive sleep apnea and are used to increase the caliber of the airway during sleep. Their primary use is for the patient who has snoring or mild to

Glenn T. Clark



Semiochemicals of the honeybee queen mandibular glands  

Microsoft Academic Search

The ontogeny of the five queen mandibular gland semiochemicals that initiate and maintain the retinue behavior of worker honeybees was investigated by quantitative splitless capillary gas chromatography. No detectable pheromone is present at the time of eclosion, but decenoic acid levels build up rapidly during the first week of the queen's life. Two aromatic components attain detectable levels later, with

Keith N. Slessor; Lori-Ann Kaminski; G. G. S. King; Mark L. Winston



Mandibular contouring surgery for purely aesthetic reasons  

Microsoft Academic Search

The mandible's contour determines the shape of the lower part of the face and thus influences the appearance of the face and neck. There are two types of operative procedures that can be used on mandibular contour and they do not require orthodontic treatment: mandible angle reduction and genioplasty. We divided the mandible angle reduction group into Types A, B,

Doo Byung Yang; Chul Gyoo Park



[Facial nerve paralysis and mandibular fracture].  


The authors describe three cases of peripheral facial nerve paralysis in patients with a mandibular fracture. In two cases, in which the onset of palsy was uncertain, the facial nerve injury was contralateral to the fractured side. Topodiagnostic tests showed neural damage at the third intrapetrosal portion and at the genicular ganglion. In one of the two patients tomography revealed a fracture line through the anterio-superior wall of the external auditory canal homolateral to the facial palsy. In the third subject palsy set in immediately after the trauma and was ipsilateral to the mandibular fracture; the facial lesion was localized at the genicular ganglion. In the first two cases, functional recovery was spontaneous (40 and 0 days after the trauma respectively). In the third subject, the nerve was decompressed surgically with a complete functional recovery two months later. The functional and clinical findings of these three cases show that a contralateral facial palsy secondary to a mandibular fracture resolves spontaneously while the traumatic displacement of the mandibular condyle may determine a temporal bone fracture sometimes followed by a lesion in the intratemporal portion of the facial nerve. An event such as the latter may delay functional recovery and thus warrant surgery such as in cases of Bell's palsy. PMID:1298156

Salonna, I; Fanizzi, P; Quaranta, A


Distraction osteogenesis in a severe mandibular deficiency  

Microsoft Academic Search

OBJECTIVE: Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, distraction with a multidirectional extraoral device was performed to gradually lengthen the corpus and ramus of a patient who had a severe hypoplastic mandible. MATERIALS AND METHODS: The patient underwent bilateral extraoral ramus and corpus distraction osteogenesis. After seven days of latency

Kerim Ortakoglu; Seniz Karacay; Metin Sencimen; Erol Akin; Aykut H Ozyigit; Osman Bengi



Unilateral regional odontodysplasia with ipsilateral mandibular malformation.  


Regional odontodysplasia is a rare developmental anomaly with an unknown cause. This disorder involves both the ectodermal and mesodermal dental layers. The affected teeth generally cannot be rehabilitated for functional use; therefore, the treatment of choice is extraction with prosthetic replacement. A unique case of unilateral regional odontodysplasia with ipsilateral mandibular malformation is reported. PMID:2356083

Raez, A G



Bilateral Mandibular Supernumerary Canines: A Case Report  

PubMed Central

Supernumerary teeth are defined as the teeth developed in excess of the number found in a normal dentition. Supernumerary canine is an extremely rare finding particularly in the mandible. This case report presents a 25-year-old female patient with the unique feature of bilateral mandibular supplemental supernumerary canines. The patient was non-syndromic without any other supernumerary teeth.

Abouei Mehrizi, Ehsan; Semyari, Hassan; Eslami Amirabadi, Gholamreza



An assessment of early mandibular growth.  


Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch and associated muscle attachment sites. These findings might be valuable in the estimation of age in unidentified individuals and to monitor prenatal growth of the mandible for the early diagnosis of conditions associated with stunted mandibular growth. PMID:22154436

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



Octacalcium phosphate collagen composites with titanium mesh facilitate alveolar augmentation in canine mandibular bone defects.  


This study was designed to investigate whether bone regeneration by implantation of octacalcium phosphate and porcine atelocollagen composite (OCP/Col) would be enhanced if mechanical stress to the implanted OCP/Col were alleviated. OCP/Col discs were implanted into an arc-shaped mandibular defect in male adult beagle dogs divided into untreated, OCP/Col, and OCP/Col/Mesh groups. In the OCP/Col/Mesh group, mechanical stress towards the implanted OCP/Col was alleviated by a titanium mesh. Bone regeneration in the three groups was compared after 6 months. Macroscopically, the alveolus in the OCP/Col/Mesh group was augmented vertically more than in the other two groups. Morphometric analysis by micro-CT showed the bone volume in the OCP/Col/Mesh group was significantly greater than in the other two groups. The augmented alveolus in the OCP/Col/Mesh group consisted of outer cortical and inner cancellous structure. Histologically, the OCP/Col/Mesh-treated alveolus was augmented by matured bone tissue along the inside of the titanium mesh. The implanted OCP/Col in the OCP/Col/Mesh and OCP/Col groups had almost disappeared. These results indicated that vertical bone regeneration by OCP/Col was efficient and successful when the mechanical stress to the implanted OCP/Col was alleviated. OCP/Col should be a useful bone substitute with active structural reconstitution. PMID:22727604

Miura, K; Matsui, K; Kawai, T; Kato, Y; Matsui, A; Suzuki, O; Kamakura, S; Echigo, S




PubMed Central

Purpose: This study evaluated the effects of phosphate-coated titanium on mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in canines. Materials and Methods: 2.2 mm × 4 mm electrolytically phosphated or non-phosphated titanium implants with acid-etched surfaces were placed in 48 mandibular sites in 6 foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At twelve weeks following implant healing, animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histological evaluation was performed on undecalcified sections. Results: Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar bone-to-implant contact was observed in phosphated and non-phosphated titanium implant sites. MAR was significantly higher near non-phosphated titanium implant surfaces than the phosphated titanium samples. No significant differences were found between dogs or implant sites. Discussion and Conclusion: Acid-etched only implants showed significantly higher mineral apposition rates compared to acid-etched, phosphate-coated implants.

Foley, Christine Hyon; Kerns, David G.; Hallmon, William W.; Rivera-Hidalgo, Francisco; Nelson, Carl J.; Spears, Robert; Dechow, Paul C.; Opperman, Lynne A.



Case studies on implant removal influencing the resolution of inferior alveolar nerve injury  

Microsoft Academic Search

Introduction Nerve injury during implant placement is a preventable, serious complication with major medico-legal implications. The incidence of implant related inferior alveolar nerve (IAN) injuries varies from 0-40%. This article presents four cases of IAN injury following mandibular implant placement with early removal, referred to the oral surgery department, King's College Hospital, London.Objectives To assess sensory disturbance and recovery in

T. Renton; N. Khawaja



Mandibular first premolar with four canals.  


A case of endodontic treatment of a mandibular first premolar exhibiting a total of four distinct root canals and four apical foramina is described. This occurrence in mandibular first premolar has rarely been reported in the endodontic literature. Endodontic treatment that considers the anatomic variation of root canal morphology is important to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation with ethylenediaminetetraacetic acid might allow the flow of sealer into the narrowed but unprepared part of the canal. This offers valuable adjuncts for the successful negotiation of calcified main canals, thereby facilitating optimum chemo-mechanical debridement of the root canal system. PMID:23382063

Du, Yi; Lee, Angeline H C; Zhang, Chengfei



Maxillofacial-derived stem cells regenerate critical mandibular bone defect.  


Stem cell-based bone tissue regeneration in the maxillofacial complex is a clinical necessity. Genetic engineering of mesenchymal stem cells (MSCs) to follow specific differentiation pathways may enhance the ability of these cells to regenerate and increase their clinical relevance. MSCs isolated from maxillofacial bone marrow (BM) are good candidates for tissue regeneration at sites of damage to the maxillofacial complex. In this study, we hypothesized that MSCs isolated from the maxillofacial complex can be engineered to overexpress the bone morphogenetic protein-2 gene and induce bone tissue regeneration in vivo. To demonstrate that the cells isolated from the maxillofacial complex were indeed MSCs, we performed a flow cytometry analysis, which revealed a high expression of mesenchyme-related markers and an absence of non-mesenchyme-related markers. In vitro, the MSCs were able to differentiate into osteogenic, chondrogenic, and adipogenic lineages. Gene delivery of the osteogenic gene BMP2 via an adenoviral vector revealed high expression levels of BMP2 protein that induced osteogenic differentiation of these cells in vitro and induced bone formation in an ectopic site in vivo. In addition, implantation of genetically engineered maxillofacial BM-derived MSCs into a mandibular defect led to regeneration of tissue at the site of the defect; this was confirmed by performing micro-computed tomography analysis. Histological analysis of the mandibles revealed osteogenic differentiation of implanted cells as well as bone tissue regeneration. We conclude that maxillofacial BM-derived MSCs can be genetically engineered to induce bone tissue regeneration in the maxillofacial complex and that this finding may be clinically relevant. PMID:18636943

Steinhardt, Yair; Aslan, Hadi; Regev, Eran; Zilberman, Yoram; Kallai, Ilan; Gazit, Dan; Gazit, Zulma



3-d volumetric evaluation of human mandibular growth.  


Bone growth is a complex process that is controlled by a multitude of mechanisms that are not fully understood.Most of the current methods employed to measure the growth of bones focus on either studying cadaveric bones from different individuals of different ages, or successive two-dimensional (2D) radiographs. Both techniques have their known limitations. The purpose of this study was to explore a technique for quantifying the three dimensional (3D) growth of an adolescent human mandible over the period of one year utilizing cone beam computed tomography (CBCT) scans taken for regular orthodontic records. Three -dimensional virtual models were created from the CBCT data using mainstream medical imaging software. A comparison between computer-generated surface meshes of successive 3-D virtual models illustrates the magnitude of relative mandible growth. The results of this work are in agreement with previously reported data from human cadaveric studies and implantable marker studies. The presented method provides a new relatively simple basis (utilizing commercially available software) to visualize and evaluate individualized 3D (mandibular) growth in vivo. PMID:22046201

Reynolds, Mathew; Reynolds, Michael; Adeeb, Samer; El-Bialy, Tarek



Proximal segment displacement in mandibular distraction osteogenesis.  


Distraction osteogenesis has been advocated for treatment of the mandibular deformity in patients with hemifacial microsomia (HFM). During the active phase, the force of distraction pushes the distal segment of the mandible down, creating a distraction gap. Because of the abnormal temporomandibular joint anatomy in HFM patients, the proximal segment may not seat in the glenoid fossa and thus may be displaced with distraction. The purpose of this study was to determine the vector(s) of proximal segment movement during mandibular distraction using a semiburied device. Two investigators traced the immediate pre-and postdistraction panoramic radiographs of 12 HFM patients (mean age at operation = 8.4 years, mean distraction = 28 mm) who had mandibular distraction with a semiburied device. Radiographic analysis, based on a vertical maxillary reference line, measured change in condylar position with angular and linear measurements. Inter-rater reliability for the tracing and analysis was shown with a correlation coefficient between 0.89 and 0.99 for all measures. Based on the angular and linear measurements, 10 of the 12 patients had superior movement of the proximal segment with distraction. Sagittal movement of the proximal segment could not be judged adequately. This study was based on measurements made on panoramic radiographs. Direct measurements could not be made; thus, it was not possible to estimate proximal segment movement in millimeters or as a percentage of total movement. Further studies to document proximal segment movement using computed tomography scans may provide more quantitative data. PMID:12000889

Padwa, Bonnie L; Zaragoza, Sandra M; Sonis, Andrew L



[Epidermoid cysts and implants. Anatomo-pathologic findings].  


A case is reported that is exceptional in more than one respect. The mandibular region was the site of development of three cysts: a radiculo-dental cyst, a coronodental cyst in appearance but which could have been an epidermoid cyst and a typical epidermoid cyst. Lingual nerve lesions are a rare, major complication of implantations. Dismounting of a stable implant is a very rare occurrence. Histopathology showed a bone integration process in contact with the major part of implant, an interposed fibrous band existing in certain sectors only. PMID:3470884

Commissionat, Y; Forest, M; Clairet, A; Al Himdani, K; Nguyen, P N



Placing Dental Implants  


Placing Dental Implants Before Placing an Implant Placing the Implants Complications from Surgery Implant Failure When you get implants, more ... Implant Most people are good candidates to get dental implants. You must have enough bone in your jaw ...


Congenital cheek teratoma with temporo-mandibular joint ankylosis managed with ultra-thin silicone sheet interpositional arthroplasty  

PubMed Central

Primary cheek teratomas are rare with < 5 reported cases. None had associated temporo mandibular joint ankylosis (TMJA). The fundamental aim in the treatment of TMJA is the successful surgical resection of ankylotic bone, prevention of recurrence, and aesthetic improvement by ensuring functional occlusion. Early treatment is necessary to promote proper growth and function of mandible and to facilitate the positive psychological development of child. Inter-positional arthroplasty with ultra-thin silicone sheet was performed. Advantages include short operative time, less foreign material in the joint space leading to negligible foreign body reactions and least chances of implant extrusion. Instead of excising a large bony segment, a thin silicone sheet was interposed and then sutured ensuring preservation of mandibular height. Aggressive post-operative physiotherapy with custom made dynamic jaw exerciser was used to prevent recurrence.

Bhatnagar, Ankur; Verma, Vinay Kumar; Purohit, Vishal



Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts ® total joint prostheses  

Microsoft Academic Search

The purpose of this study was to evaluate skeletal and dental stability in patients who had temporomandibular joint (TMJ) reconstruction and mandibular counterclockwise advancement using TMJ Concepts total joint prostheses (TMJ Concepts Inc. Ventura, CA) with maxillary osteotomies being performed at the same operation. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford).

K. E. Dela Coleta; L. M. Wolford; J. R. Gonçalves; A. dos Santos Pinto; L. P. Pinto; D. S. Cassano



Sensory nerve impairment following mandibular third molar surgery  

Microsoft Academic Search

Purpose: This prospective study reports the rate and factors influencing sensory impairment of the inferior alveolar and lingual nerves after the removal of impacted mandibular third molars under local anesthesia. Patients and Methods: There were 741 patients with 741 mandibular third molars removed under local anesthesia during a 3-year period from 1994 to 1997. Standardized data collection included the patient's

Anwar B Bataineh



Stability of transverse expansion in the mandibular arch  

Microsoft Academic Search

This was a retrospective, longitudinal cephalometric and cast study of 29 white patients at pretreatment, posttreatment, and an average of 6 years 3 months postretention. The goal was to assess changes with treatment and retention with the expanding mandibular lingual arch appliance in conjunction with fixed edgewise treatment. Seven mandibular cast measurements were assessed, including arch crowding, arch perimeter, arch

Jeffrey A Housley; Ram S Nanda; G. Fräns Currier; Dale E McCune



A biomechanical evaluation of mandibular condyle fracture plating techniques  

Microsoft Academic Search

Objectives: The purpose of this investigation was to evaluate the biomechanical behavior of various rigid internal fixation techniques for mandibular condylar process fractures. Materials and Methods: Synthetic mandible replicas (Synbone, Landquart, Switzerland) were used to evaluate a control, and four monocortical mandibular condyle plating techniques. Each group was subjected to linear loading in lateral to medial, medial to lateral and

Richard H. Haug; Gilman P. Peterson; Michele Goltz



Progressive condylar resorption after mandibular advancement.  


Progressive condylar resorption is an irreversible complication and a factor in the development of late skeletal relapse after orthognathic surgery. We have evaluated cephalometric characteristics, signs and symptoms in the temporomandibular joint (TMJ), and surgical factors in six patients (one man and five women) who developed it after orthognathic surgery. The findings in preoperative cephalograms indicated that the patients had clockwise rotation of the mandible and retrognathism because of a small SNB angle, a wide mandibular plane angle, and a "minus" value for inclination of the ramus. There were erosions or deformities of the condyles, or both, on three-dimensional computed tomography (CT) taken before treatment. The mean (SD) anterior movement of the mandible at operation was 12.1 (3.9)mm and the mean relapse was -6.4 (2.5)mm. The mean change in posterior facial height was 4.5 (2.1)mm at operation and the mean relapse was -5.3 (1.8)mm. Two patients had click, or pain, or both, preoperatively. The click disappeared in one patient postoperatively, but one of the patients who had been symptom-free developed crepitus postoperatively. In the classified resorption pattern, posterior-superior bone loss was seen in three cases, anterior-superior bone loss in two, and superior bone loss in one. Progressive condylar resorption after orthognathic surgery is multifactorial, and some of the risk factors are inter-related. Patients with clockwise rotation of the mandible and retrognathism in preoperative cephalograms; erosion, or deformity of the condyle, or both, on preoperative CT; and wide mandibular advancement and counterclockwise rotation of the mandibular proximal segment at operation, seemed to be at risk. The mandible should therefore be advanced only when the condyles are stable on radiographs, and careful attention should be paid to postoperative mechanical loading on the TMJ in high-risk patients. PMID:21440343

Kobayashi, Tadaharu; Izumi, Naoya; Kojima, Taku; Sakagami, Naoko; Saito, Isao; Saito, Chikara



Cochlear Implants  


... and sends them to different regions of the auditory nerve. An implant does not restore normal hearing. ... portions of the ear and directly stimulate the auditory nerve. Signals generated by the implant are sent ...


Mandibular distraction in neonates: indications, technique, results  

PubMed Central

Background The Pierre Robin Sequence features were first described by Robin in 1923 and include micrognathia, glossoptosis and respiratory distress with an incidence estimated as 1:8,500 to 1:20,000 newborns. Upper airway obstruction and feeding difficulties are the main concerns related to the pathology. Mandibular distraction should be considered a treatment option (when other treatments result inadequate). Patiants and methods Ten patients between the ages of 1 month and 2 years with severe micrognathia and airway obstruction were treated with Mandibular Distraction Osteogenesis (MDO). All patients underwent fibroscopic examination of the upper airway and a radiographic imaging and/or computed tomography scans to detect malformations and to confirm that the obstruction was caused by posterior tongue displacement. All patients were evaluated by a multidisciplinary team. Indications for surgery included frequent apneic episodes with severe desaturation (70%). Gavage therapy was employed in all patients since oral feeding was not possible. The two tracheotomy patients were 5 months and 2 years old respectively, and the distraction procedure was performed to remove the tracheotomy tube. All patients were treated with bilateral mandibular distraction: two cases with an external multivector distraction device, six cases with an internal non-resorbable device and two cases with an internal resorbable device. In one case, the patient with Goldenhar's Syndrome, the procedure was repeated. Results The resolution of symptoms was obtained in all patients, and, when present, tracheotomy was removed without complications. Of the two patients with pre-existing tracheotomies, in the younger patient (5 months old) the tracheotomy was removed 7 days postoperatively. In the Goldenhar's syndrome case (2 years old) a Montgomery device was necessary for 6 months due to the presence of tracheotomy-inducted tracheomalacia. Patients were discharged when the endpoint was obtained: symptoms and signs of airway obstruction were resolved, PAS and maxillomandibular relationship improved, and tracheotomy, when present, removed. During the follow-up, no injury to the inferior alveolar nerve was noted and scarring was significant in only the two cases treated with external devices. Conclusion Mandibular Distraction Osteogenesis is a good solution in solving respiratory distress when other procedures are failed in paediatric patients with severe micrognatia.



Aplasia of the mandibular condyle associated with some orthopaedic abnormalities.  


A rare case of aplasia of mandibular condyle associated with some other orthopaedic problems is presented. A 5-year-old boy attended our clinic with a chief complaint of facial asymmetry and chewing difficulty. The mandible was deviated to the left. The occlusion also showed a deflection to the left of the mandibular midline. He also had walking difficulty owing to a hip abnormality. Panoramic radiographic examination of the patient revealed that the left mandibular condyl was totally absent. The right condyle was unremarkable. His history revealed neither trauma nor any significant disease. Aplasia is a rare anomaly and means the insufficient development of the mandibular condyle. True agnesis of the mandibular condyle is extremely rare. Association of the manifestations of the patient with some orthopaedic problems makes this case interesting. PMID:22116127

Canger, E M; Celenk, P



Backward distraction osteogenesis in a patient with severe mandibular micrognathia.  


Maxillary skeletal prognathism can involve severe mandibular micrognathia with marked mandibular retrognathism or hypoplasia. For patients with such a condition, a conventional treatment is mandibular advancement by sagittal split ramus osteotomy (SSRO). This procedure has problems such as insufficient advancement, instability of jaw position, and postoperative relapse. Thus, in recent years, mandibular distraction osteogenesis has been used in some patients. Mandibular distraction has many advantages, but an ideal occlusion is difficult to achieve using this procedure. That is, 3-dimensional control cannot be attained using an internal device that is unidirectional. This report describes a case of severe mandibular micrognathia in a 14-year-old girl treated using backward distraction osteogenesis. This procedure was first reported by Ishii et al (Jpn J Jaw Deform 2004; 14:49) and involves a combination of SSRO and ramus distraction osteogenesis. In the present study, intermaxillary fixation in centric occlusion was performed after osteotomy, and proximal bone segments were distracted in a posterosuperior direction. This procedure is a superior surgical technique that avoids the drawbacks of SSRO and conventional mandibular distraction. However, it applies a large load to the temporomandibular joints and requires thorough management. Thus, careful evaluation needs to be made of the indication for backward distraction osteogenesis. PMID:24036745

Mitsukawa, Nobuyuki; Morishita, Tadashi; Saiga, Atsuomi; Akita, Shinsuke; Kubota, Yoshitaka; Satoh, Kaneshige



Original sagittal split osteotomy revisited for mandibular distraction.  


Introduction: A malformed mandible and an abnormally positioned mandibular foramen make it difficult to plan an ideal osteotomy line for mandibular distraction. In addition, there have been reports of such complications as nonunion, damage and stretch injury of the inferior alveolar nerve and tooth germ damage when conventional osteotomy or corticotomy are used for mandibular distraction. The authors utilized the original sagittal split ramus osteotomy for mandibular distraction. Patients and Methods: Five patients (three unilateral hemifacial microsomia, one bilateral hemifacial microsomia, and one mandibular retrusion) were included in this study of distraction osteogenesis using the sagittal split ramus osteotomy. Extraoral distraction devices were applied to the first four patients. An intraoral device with mono-cortical screw fixation was used for the fifth patient. Result: In all five cases, the results of the distraction were satisfactory. Complications (as listed) of conventional osteotomy when used for distraction were avoided. Satisfactory results were achieved and these were also well maintained postoperatively (mean follow up: 36 months). Conclusion: The authors believe that sagittal osteotomy for mandibular distraction osteogenesis makes it possible, to avoid injury to the inferior alveolar nerve during operation and stretching injury during distraction and to prevent tooth germ injury. It is also possible to diversify the osteotomy line for various force vectors to enlarge the bony contact surface area. Therefore, we suggest that sagittal split ramus osteotomy should be used as a preferred modification of osteotomy for mandibular distraction. Copyright 2001 European Association for Cranio-Maxillofacial Surgery. PMID:11403554

Choi, Jin-Young; Hwang, Kyung-Gyun; Baek, Seung-Hak; Lee, Jong-Ho; Kim, Tae-Woo; Kim, Myung-Jin; Chang, Young-II



Peri-Implant Diseases  


... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...


Cone beam computed tomography in oral implants  

PubMed Central

Cone beam computed tomography (CBCT) scanners for the oral and maxillofacial region were pioneered in the late 1990s independently by Arai et al. in Japan and Mozzo et al. CBCT has a lower dose of radiation, minimal metal artifacts, reduced costs, easier accessibility, and easier handling than multislice computed tomography (MSCT); however, the latter is still considered a better choice for the analysis of bone density using a Hounsfield unit (HU) scale. Oral implants require localized area of oral and maxillofacial area for radiation exposure; so, CBCT is an ideal choice. CBCT scans help in the planning of oral implants; they enable measurement of the distance between the alveolar crest and mandibular canal to avoid impingement of inferior alveolar nerve, avoid perforation of the mandibular posterior lingual undercut, and assess the density and quality of bone, and help in planning of the oral implant in the maxilla with special attention to the nasopalatine canal and maxillary sinus. Hence, CBCT reduces the overall exposure to radiation.

Gupta, Jyoti; Ali, Syed Parveez



Stress and strain analysis of the bone-implant interface: a comparison of fiber-reinforced composite and titanium implants utilizing 3-dimensional finite element study.  


This study analyzed stress and strain mediated by 2 different implant materials, titanium (Ti) and experimental fiber-reinforced composite (FRC), on the implant and on the bone tissue surrounding the implant. Three-dimensional finite element models constructed from a mandibular bone and an implant were subjected to a load of 50 N in vertical and horizontal directions. Postprocessing files allowed the calculation of stress and strain within the implant materials and stresses at the bone-to-implant interface (stress path). Maximum stress concentrations were located around the implant on the rim of the cortical bone in both implant materials; Ti and overall stresses decreased toward the Ti implant apex. In the FRC implant, a stress value of 0.6 to 2.0 MPa was detected not only on the screw threads but also on the implant surface between the threads. Clear differences were observed in the strain distribution between the materials. Based on the results, the vertical load stress range of the FRC implant was close to the stress level for optimal bone growth. Furthermore, the stress at the bone around the FRC implant was more evenly distributed than that with Ti implant. PMID:20545537

Shinya, Akikazu; Ballo, Ahmed M; Lassila, Lippo V J; Shinya, Akiyoshi; Närhi, Timo O; Vallittu, Pekka K



Endodontic management of four rooted mandibular first premolar  

PubMed Central

Mandibular premolars have earned the reputation for having aberrant anatomy. The literature is replete with reports of extra canals in mandibular first premolars, but reports about the incidence of extra roots in these teeth are quite rare. This paper attempts at explaining a rare case of successful endodontic management of a four-rooted mandibular first premolar with diagnostic, interoperative and postoperative radiographic records along with a substantial data on the incidence of extra roots in these teeth. The standard method of radiographic appraisal was maintained as the criteria for determining the presence of extra roots.

Vaghela, Dakshita Joy; Sinha, Ashish Amit



Peripheral Osteoma of the Mandibular Notch: Report of a Case  

PubMed Central

Osteoma is a benign, slow-growing osteogenic tumor that sometimes arises from the craniomaxillofacial region, such as the sinus, temporal or jaw bones. Osteoma consists of compact or cancellous bone that may be peripheral, central or extraskeletal type. Peripheral osteoma arises from the periosteum and is commonly a unilateral, pedunculated mushroom-like mass. Peripheral osteoma of the mandible is relatively uncommon, and peripheral osteoma of the mandibular notch is extremely rare, although many cases arise from the mandibular body, angle, condyle, or coronoid process. We report here an unusual peripheral osteoma of the mandibular notch in a 78-year-old nonsyndromic female.

Iwai, Toshinori; Izumi, Toshiharu; Baba, Junichi; Maegawa, Jiro; Mitsudo, Kenji; Tohnai, Iwai



[Isolated mandibular metastases. Therapeutic strategy. Apropos of 7 cases].  


Among the mandibular tumours, the secondary malignant tumours are uncommon. We relate 7 cases observed between 1977 and 1995. Two cases have revealed the original cancer (rectum, prostate). The five other cases were discovered during the evolution of the original cancer (colon, lung, kidney, thyroid, breast). These 7 mandibular metastases were isolated. The treatment included a mandibular resection in 6 cases. In one of these cases, the reconstruction was performed with a free vascularized fibular transplant with success. Among the seven cases, two patients are alive, at the present time, with a mean follow-up of 3 years. This justifies a curative treatment. PMID:9616904

Germain, M A; Marandas, P; Leridant, A M; Julieron, M; Schlumberger, M; Mamelle, G; Domenge, C



A simple method to locate mandibular foramen: preliminary radiological study  

Microsoft Academic Search

Introduction  The position of mandibular foramen is variable at the medial aspect of mandibular ramus. Nevertheless its location is useful\\u000a for the oral and maxillofacial surgeon in orthognatic surgery, especially in vertical ramus osteotomy (VRO) procedure. The\\u000a aim of our study is to analyse the position of mandibular foramen in order to provide simple and reliable surgical landmarks.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  A

Olivier Trost; Vivien Salignon; Nicolas Cheynel; Gabriel Malka; Pierre Trouilloud




PubMed Central

PURPOSE Tissue engineering solutions focused on the temporomandibular joint (TMJ) have expanded in number and variety over the past decade to address the treatment of TMJ disorders. The existing literature on approaches for healing small defects in the TMJ condylar cartilage and subchondral bone, however, is sparse. The purpose of this study was thus to evaluate the performance of a novel gradient-based scaffolding approach to regenerate osteochondral defects in the rabbit mandibular condyle. MATERIALS AND METHODS Miniature bioactive plugs for regeneration of small mandibular condylar defects in New Zealand White rabbits were fabricated. The plugs were constructed from poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres with a gradient transition between cartilage-promoting and bone-promoting growth factors. RESULTS At six weeks of healing, results suggested that the implants provided support for the neo-synthesized tissue as evidenced by histology and 9.4T magnetic resonance imaging. CONCLUSION The inclusion of bioactive factors in a gradient-based scaffolding design is a promising new treatment strategy for focal defect repair in the TMJ.

Dormer, Nathan H.; Busaidy, Kamal; Berkland, Cory J.; Detamore, Michael S.



Implantable Microimagers  

PubMed Central

Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun



Reconstruction of mandibular defects in irradiated patients  

SciTech Connect

In this prospective study, mandibular reconstruction using titanium plates was evaluated in 31 patients treated between July 1988 and January 1990. Sixteen patients had prior surgery; 13 had prior radiotherapy. In 11 patients, prior radiation and surgery had failed. Sixteen patients received postoperative radiotherapy either in standard or accelerated fractions. Twelve patients had complications of either intraoral (8), extraoral (5), or combined (1) plate exposure or fistula formation (2). Factors significantly related to complications were poor nutrition, accelerated radiation, and recurrence. Sixty-one percent of all patients healed uneventfully. When patients with complications secondary to recurrence who subsequently died were excluded, the success rate was 73%. Only one patient had an unacceptable result that produced a cosmetic and functional deformity despite secondary repair.

Klotch, D.W.; Gump, J.; Kuhn, L. (Univ. of South Florida, Tampa (USA))



Effects of irradiation on mandibular scintigraphy  

SciTech Connect

Technetium-99m methylene diphosphonate (Sn) scintigraphy with computer analysis was used to investigate alterations in the pathophysiology of the normal mandible and the pathologic mandible during and after irradiation. Slight but significant elevations of uptake levels were recorded as an early effect of irradiation. The elevations correlated with the duration of treatment and normalized over a follow-up period of 6 to 12 mo. Increased mandibular metabolism was found during irradiation and in osteomyelitis and osteoradionecrosis of the mandible. Scintigraphy with computer analysis proved a simple and valid method in the evaluation of early irradiation damage and pathophysiologic conditions of the mandible. The method can also be used to predict whether the irradiation damage will become irreversible.

Aitasalo, K.; Ruotsalainen, P.



[Optimizing therapeutic methods in mandibular fractures].  


The authors present various methods for immobilizing mandibular fractures, stressing their advantages and disadvantages. They describe modern surgical methods used in immobilizing these fractures, considering methods employed in stable, functional osteosynthesis that have improved indications for surgical therapy, and that have made obsolete intermaxillary immobilization. These methods are more acceptable for the patient because they allow for a completely normal diet, as well as the maintenance of a normal hygiene in the buccal cavity. Evolution of the recovery is more easily followed, and in case of complications interventions are easily carried out in a short time. The presence of functional stimuli enhances the development of a good callus, and the full recovery is shortened by 2-3 weeks. PMID:2978709

G?nu??, N; Stroescu, I; Vasiliu, D; Florian, B; Maftei, I; Herescu, C; Ni?escu, M; Filipescu, A; Sterian, L


Assessment of mandibular growth by skeletal scintigraphy  

SciTech Connect

Accurate assessment of facial skeletal growth remains a major problem in craniomaxillofacial surgery. Current methods include: (1) comparisons of chronologic age with growth histories of the patient and the family, (2) hand-wrist radiographs compared with a standard, and (3) serial cephalometric radiographs. Uptake of technetium-99m methylene diphosphonate into bone is a reflection of current metabolic activity and blood flow. Therefore, scintigraphy with this radiopharmaceutical might serve as a good method of assessing skeletal growth. Thirty-four patients, ranging in age from 15 months to 22 years, who were undergoing skeletal scintigrams for acute pathologic conditions of the extremities, were used to develop standards of uptake based on age and skeletal maturation. The results indicate that skeletal scintigraphy may be useful in evaluation of mandibular growth.

Kaban, L.B.; Cisneros, G.J.; Heyman, S.; Treves, S.



High Productivity Implantation ``PARTIAL IMPLANT''  

NASA Astrophysics Data System (ADS)

The patterned ion implantation ``PARTIAL IMPLANT'' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is ``DIVIDE PARTIAL IMPLANT,'' that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is ``RING PARTIAL IMPLANT'' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao



Growth factor-mediated vertical mandibular ridge augmentation: a case report.  


Posterior vertical alveolar ridge deficiencies are challenging defects to treat predictably and often require autogenous bone-harvesting procedures. Traditional treatment modalities, eg, guided bone regeneration, distraction osteogenesis, and autogenous grafts, present with a number of potential complications and limited success when used to restore vertical ridge height. Recent advances in recombinant growth factor technology may provide viable, alternative therapies for the treatment of significant alveolar ridge deficiencies. This proof-of-principle case report examines the utility and effectiveness of using a composite graft of freeze-dried bone allograft and recombinant human platelet-derived growth factor BB in conjunction with an overlying titanium mesh to regenerate well-vascularized bone in a significant posterior mandibular ridge defect prior to implant placement. The important role of the overlying periosteum as a possible key source of osteogenic cells during growth factor-enhanced regenerative procedures is emphasized. PMID:23998157

Guze, Kevin A; Arguello, Emilio; Kim, David; Nevins, Myron; Karimbux, Nadeem Y


The soft tissue barrier at implants and teeth.  


In the present animal experiment, analyses and comparisons were made between the structure and composition of clinically healthy supraalveolar soft tissues adjacent to implants and teeth. 5 beagle dogs were used. The right mandibular premolar region was selected in each dog for placement of titanium implants, while the left mandibular premolar region served as control. Extractions of the mandibular premolars were preformed, healing allowed, following which titanium fixtures were installed in the edentolous premolar region. Abutment connection was carried out 3 months later. After another 2 months of healing, plaque control was initiated and maintained for 8 weeks. At the end of the plaque control period, clinical examinations were performed and biopsies harvested from the implant site and the contralateral premolar tooth region. Following fixation and decalcification, all tissue samples were embedded in EPON and examined by histometric and morphometric means. The result from the analyses demonstrated that the periimplant mucosa which formed at titanium implants following abutment connection had many features in common with gingival tissue at teeth. Thus, like the gingiva, the peri-implant mucosa established a cuff-like barrier which adhered to the surface of the titanium abutment. Further, both the gingiva and the peri-implant mucosa had a well-keratinized oral epithelium which was continuous with a junctional epithelium that faced the enamel or the titanium surface. In the periimplant mucosa, the collagen fibers appeared to commence at the marginal bone and were parallel with the abutment surface. All gingival and periimplant units examined were free from infiltrates of inflammatory cells. It was suggested that under the conditions of study, both types of soft tissues, gingiva and periimplant mucosa, have a proper potential to prevent subgingival plaque formation. PMID:1809403

Berglundh, T; Lindhe, J; Ericsson, I; Marinello, C P; Liljenberg, B; Thomsen, P


Endodontic management of middle mesial canal of the mandibular molar.  


Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep



Mandibular condylar pseudocyst: An introduction to the orthodontist.  


The aims of this article are to introduce mandibular condylar pseudocysts to orthodontists, present 2 relevant case reports, and discuss possible differential diagnoses. Condylar pseudocyst is a radiologic variant of pterygoid fovea, which is the site of insertion of the lateral pterygoid muscle to the head of the mandibular condyle. A pathognomonic picture of a solitary well-defined radiolucency with radiopaque borders, located on the anterior aspect of the condyle in an asymptomatic orthodontic patient, is characteristic. PMID:24075670

Yitschaky, Oded; Friedlander-Barenboim, Silvina; Friedman, Menahem; Tzur-Gadassi, Liat; Zadik, Yehuda



Mandibular morphology and diet in the genus Cebus  

Microsoft Academic Search

The influence of hard-object feeding on the size and shape of the mandibular corpus was investigated through a comparative\\u000a biomechanical analysis of the jaws of adult femaleCebus apella andCebus capucinus. Computed tomography (CT) was used to discern the amount and distribution of cortical bone at M2 and symphyseal cross sections. From these data, the biomechanical properties of the mandibular corpus

David J. Daegling



Impaction of permanent mandibular second molar: A retrospective study  

PubMed Central

Objective: To determine the prevalence of impacted mandibular second molar (MM2) and the association between MM2 impaction and crowding. The clinical significance of the angle between first and second mandibular molar and of the space between the first mandibular molar (MM1) and the anterior margin of mandibular ramus in MM2 impaction were also evaluated. Material and Methods: In this retrospective study , from the dental records of 2,945 caucasian young orthodontics patients, 40 subjects with MM2 impaction were included in a study group (SG) and compared with a control group (CG) of 200 subjects without MM2 impactions. The crowding, the angle of inclination of MM2, the distance between MM1 and mandibular ramus, the canine and molar relationships, and the lower centre line discrepancy were measured. For the statistical analysis , descriptive statistics and t-Student for independent sample groups were used. Results: The prevalence of impacted MM2 was 1.36%. The independent-Samples t-Test between SG and CG showed: the presence of crowding (P?0.001), an higher angle values of MM2 inclination (P?0.001) and a smaller distance between MM1 and the anterior margin of mandibular ramus (P?0.001) in the SG. Conclusion: The impaction of MM2 is a relatively rare occurrence in orthodontic caucasian populations. The crowding, a higher angle values of MM2 inclination and a reduced distance between MM1 and the anterior margin of mandibular ramus, at the time of one third of MM2 root formation (T1), characterize MM2 impaction. Key words:Impacted mandibular second molar, impaction, orthodontics.

Altieri, Federica; Di Mambro, Alfonso; Galluccio, Gabriella; Barbato, Ersilia



Effects of material porosity on implant bonding strength in a craniofacial model.  


Alloplastic craniofacial implantation is a developing surgical option. Several alloplastic materials are available with a porous feature. While porosity may permit bone ingrowth, it is unclear whether it offers improved implant fixation over that of nonporous bone substitutes in the craniofacial skeleton. Bilateral mandibular ramus defects were created and reconstructed with porous and nonporous block implants in the mature rabbit. At 3, 6, and 12 months postoperatively, the mandibles were removed and prepared so that only the bone-implant interface connected the proximal and distal segments. The anterior mandible was then loaded to destruction. The fatigue load (in kg) for each implant was obtained and statistically compared. Significant differences in fatigue loads between the implant types occurred at all postoperative periods with the porous block material consistently exhibiting the greater resistance to separation. Resistance to fatigue fracturing for either implant type did not increase after the sixth postoperative month. PMID:2098179

Eppley, B L; Sadove, A M



Cochlear Implants  


... studying large groups of children who were identified early with hearing loss and implanted with a cochlear implant. Knowledge from this research will shed light on the variables most related to improved speech and language acquisition as well as reading and higher academic performance ...


Clinical application of a custom-made bioresorbable raw particulate hydroxyapatite/poly-L-lactide mesh tray for mandibular reconstruction.  


Mandibular reconstruction using particulate cancellous bone and marrow (PCBM) allows functional oral reconstruction. Although ready-made titanium trays are the most common material used in this method, they have some disadvantages such as difficulty in making them form a suitable contour for the defect, and the need for removal. A forged composite of raw particulate hydroxyapatite (HA)/poly-L-lactide (PLLA) is a bioresorbable material that is stronger than pure PLLA and induces bone formation more rapidly. We present two cases successfully treated with custom-made bioresorbable HA/PLLA mesh trays for mandibular reconstruction. A 29-year-old woman with recurrent ameloblastoma and a 66-year-old man with a recurrent keratinized odontogenic tumor of the mandible gave informed consent for this reconstruction technique. Mesh sheets of HA/PLLA were customized by a rapid prototyping method based on computed tomography (CT) data. Marginal resection of the tumor was carried out, and PCBM was harvested from the bilateral posterior iliac crests. PCBM and platelet-rich plasma were transferred to the tray, and the tray was fixed rigidly with HA/PLLA screws. In the second case, dental implants were inserted. There has been no bone resorption for over 2 years since reconstruction in these two cases, and the inserted dental implants have been free from any complications 1 year after loading. The average CT value in Hounsfield units (HU) of the implant sites of two cases was 790. In conclusion, the customized HA/PLLA tray was easily adapted to the mandible, and fine bone quality was obtained. These cases show that this tray system contributed to functional oral rehabilitation with dental implants. PMID:20155513

Matsuo, Akira; Chiba, Hiroshige; Takahashi, Hidetoshi; Toyoda, Jun; Abukawa, Harutsugi



[Clinical study of mandibular condyle injury].  


Mandibular condyle fractures develop frequently and show the variable type of injury and complication. New opinions have emerged from recent investigation into condylar fractures. The author investigated 246 patients with condylar fractures who visited SNUDH from January 1980 to August, 1988, 8. with regard to clinical and treatment aspects, area and displacement of fractures, associated teeth injury and other body injury, complications. At last I have got the following results. 1. The incidence to condylar fractures in a series of 765 mandibular fractures may be as high as 32.2%. 2. The male patients are 3 times more than female patients. The highest frequency was recorded in the group 21-30 years of age. (34.1%). 3. Falls caused the greatest number of condylar fractures (45.2%) and next was in assult (25.6%), traffic accidents (22.4%). 4. Unilateral condylar fractures were present in 74.8%, giving a left: right ratio of 1.2:1. In cases of unilateral fracture, subcondylar fractures were by far the commonest (32.9%) but in cases of bilateral fracture, condylar neck fractures were by far the commonest. In children under 15 years of age, condylar neck fractures were more common but in patients over 16 years of age, subcondylar fractures were common. 5. Anteromedial fracture dislocations were by far the commonest (20.3%). In children under 15 years of age, fracture deviations were common but in patients over 16 years of age, fracture displacements were common. 6. 44.7% of patients with condylar fractures sustained the teeth injuries. Teeth fractures were by far the commonest. 7. Single condylar fractures showed a frequency of 30.5%. Of the concomitant fractures elsewhere in the mandible, symphysis fractures were by far the commonest (54.1%). 8. Associated other body injuries showed a frequency of 28.0%. Of them, head injuries were by far the commonest. 9. The mean interval from injury to treatment was 14.3 days. Of the treatment of condylar fractures, open reduction was by far the commonest (70.3%). Closed reduction comprised 19.9% and functional therapy comprised 8.5%. 10. In 67 patients with possible follow up period, the following complications were developed, two ankylosis, anterior open bite, mouth opening limitation, mouth opening deviation. PMID:2489622

Kim, Y K; Min, B I



Control of human mandibular posture during locomotion  

PubMed Central

Mandibular movements and masseter muscle activity were measured in humans during hopping, walking and running to determine whether reflexes contribute to the maintenance of jaw position during locomotion. In initial experiments, subjects hopped so that they landed either on their toes or on their heel. Landing on the toes provoked only small mandibular movements and no reflex responses in the masseter electromyogram (EMG). Landing on the heels with the jaw muscles relaxed caused the mandible to move vertically downwards relative to the maxilla, and evoked a brisk reflex response in the masseter at monosynaptic latency. Neither this relative movement of the mandible nor the reflex was seen when the teeth were clenched: hence the reflex is not the result of vestibular activation during head movement. The same variables were measured in a second series of experiments while subjects stood, walked and ran at various speeds and at various inclinations on a treadmill. During walking, the vertical movements of the head and therefore the mandible were slow and small, and there was no tonic masseter EMG or gait-related activity in the jaw-closing muscles. When subjects ran, the vertical head and jaw movement depended on the running speed and the inclination of the treadmill. Landing on the heels induced larger movements than landing on the toes. About 10 ms after each foot-strike, the mandible moved downwards relative to the maxilla, thereby stretching the jaw-closing muscles and activating them at segmental reflex latency. This caused the mandible to move back upwards. The strength of the reflex response was related to the speed and amplitude of the vertical jaw movement following landing. It is concluded that, during walking, the small, slow movements of the mandible relative to the maxilla are subthreshold for stretch reflexes in the jaw muscles: i.e. the mandible is supported by visco-elasticity of the soft tissues in the masticatory system. However, the brisker downward movements of the mandible after heel-landing during hopping and running evoke segmental reflex responses which contribute to the active maintenance of the posture of the mandible. This is a unique demonstration of how a stretch reflex operates to maintain posture under entirely natural conditions.

Miles, Timothy S; Flavel, Stanley C; Nordstrom, Michael A



Computer-aided design and manufacturing and rapid prototyped nanoscale hydroxyapatite/polyamide (n-HA/PA) construction for condylar defect caused by mandibular angle ostectomy.  


The fracture or defect of the mandibular condyle is one of the serious complications during angle-reduction ostectomy. Reconstruction of such defects also is a daunting task. The case report describes a method based on computer-aided design/computer-aided manufacturing (CAD/CAM) and rapid prototyping nanoscale hydroxyapatite/polyamide (n-HA/PA) for individual design, fabrication, and implantation of a mandibular condyle. A 27-year-old woman with a square-shaped face who had previously undergone mandibular angle reduction reported with malocclusion, deviated mouth, collapse of the right side of the face, and masticatory problems. The reason for the problems was the unintended removal of the condyle during the ostectomy procedure. Using computed tomography (CT) data, a biomimetic n-HA/PA scaffold, and CAD/CAM for rapid prototyping by three-dimensional (3D) printing, a perfect-fitting condylar implant was fabricated. A surgical guide system also was developed to reproduce the procedures accurately so a perfect fit could be obtained during surgery. The patient ultimately regained reasonable jaw contour and appearance, as well as appreciable temporomandibular joint (TMJ) function. PMID:20972567

Li, Jihua; Hsu, Yuchun; Luo, En; Khadka, Ashish; Hu, Jing



Examination of the relationship between mandibular position and body posture.  


The purpose of this study was to evaluate the effect of changing mandibular position on body posture and reciprocally, body posture on mandibular position. Forty-five (45) asymptomatic subjects (24 males and 21 females, ages 21-53 years, mean age 30.7 years) were included in this study and randomly assigned to one of two groups, based on the table of random numbers. The only difference between group I and group II was the sequence of the testing. The MatScan (Tekscan, Inc., South Boston, MA) system was used to measure the result of changes in body posture (center of foot pressure: COP) while subjects maintained the following 5 mandibular positions: (1) rest position, (2) centric occlusion, (3) clinically midlined jaw position with the labial frena aligned, (4) a placebo wax appliance, worn around the labial surfaces of the teeth and (5) right eccentric mandibular position. The T-Scan II (Tekscan, Inc., South Boston, MA) system was used to analyze occlusal force distribution in two postural positions, with and without a heel lift under the right foot. Total trajectory length of COP in centric occlusion was shorter than in the rest position (p < 0.05). COP area in right eccentric mandibular position was larger than in centric occlusion (p < 0.05). When subjects used a heel lift under the right foot, occlusal forces shifted to the right side compared to no heel lift (p < 0.01). Based on these findings, it was concluded that changing mandibular position affected body posture. Conversely, changing body posture affected mandibular position. PMID:17983123

Sakaguchi, Kiwamu; Mehta, Noshir R; Abdallah, Emad F; Forgione, Albert G; Hirayama, Hiroshi; Kawasaki, Takao; Yokoyama, Atsuro



Distraction osteogenesis in a severe mandibular deficiency  

PubMed Central

Objective Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, distraction with a multidirectional extraoral device was performed to gradually lengthen the corpus and ramus of a patient who had a severe hypoplastic mandible. Materials and methods The patient underwent bilateral extraoral ramus and corpus distraction osteogenesis. After seven days of latency period, distraction was performed 0.5 mm twice a day. Subsequent consolidation period was 12 weeks. Results The patient's mandible was elongated successfully. Cephalometric analysis revealed that ANB angle decreased from 13° to 6°, overjet of 15 mm decreased to 4 mm, corpus length increased from 49 mm to 67 mm, and ramus length increased from 41 mm to 43 mm. Posterior airway space (PAS) also increased due to advancement of the mandible. In stereolithographic model evaluation it was determined that the distances from condylion to gonion and from gonion to pogonion increased. Conclusion Satisfactory results from both aesthetic and functional standpoints were obtained by distraction osteogenesis of the ramus and corpus.

Ortakoglu, Kerim; Karacay, Seniz; Sencimen, Metin; Akin, Erol; Ozyigit, Aykut H; Bengi, Osman



On the reversibility of mandibular symphyseal fusion.  


Experimental and comparative studies suggest that a major determinant of increased ossification of the mandibular symphysis is elevated masticatory stress related to a mechanically challenging diet. However, the morphology of this joint tracks variation in dietary properties in only some mammalian clades. Extant anthropoid primates are a notable exception: synostosis is ubiquitous in this speciose group, despite its great age and diverse array of feeding adaptations. One possible explanation for this pattern is that, once synostosis evolves, reversion to a lesser degree of fusion is unlikely or even constrained. If correct, this has important implications for functional and phylogenetic analyses of the mammalian feeding apparatus. To test this hypothesis, we generated a molecular tree for 76 vespertilionoid and noctilionoid chiropterans using Bayesian phylogenetic analysis and examined character evolution using parsimony and likelihood ancestral-state reconstructions along with the binary state speciation and extinction (BiSSE) model. Results indicate that reversals have occurred within Vespertilionoidea. In contrast, noctilionoids exhibit an anthropoid-like pattern, which suggests that more detailed comparisons of the functional and developmental bases for fusion in these bat clades may provide insight into why fusion is maintained in some lineages but not in others. Potential functional and developmental explanations for the lack of reversal are discussed. PMID:22946814

Scott, Jeremiah E; Lack, Justin B; Ravosa, Matthew J



Geriatric slim implants for complete denture wearers: clinical aspects and perspectives  

PubMed Central

Background Advances made in prevention have helped postpone complete edentulism in older patients. However, in the elderly, the physiological state reduces patients’ ability to adapt to oral rehabilitation and degrades the patient’s oral condition. Consequently, elderly edentulous subjects avoid many types of foods, which can lead to substantial nutritional consequences. Complete dentures retained by implants are, currently, the treatment of reference in prosthodontic mandibular rehabilitation. Indeed, the mandibular symphysis generally tolerates implantation, even when the mandible is strongly resorbed. However, in the elderly, implant rehabilitation is compromised by the complexity of the surgical protocol and possible postoperative complications. In this context, the use of geriatric “slim implants” (GSI) offers an interesting alternative. Methods In the present study, the surgical and prosthetic procedures for the use of GSI in a French dental hospital are presented. The objective was the stabilization of a complete mandibular denture in an elderly person, with the immediate implantation of four GSI. Results The operating procedure was found to be less invasive, less expensive, simpler, and more efficient than the conventional procedure. Conclusion The result strongly suggests that this protocol could be used systematically to treat complete edentulism in very elderly patients. Long-term monitoring and the evaluation of the reliability of this type of rehabilitation should be undertaken.

Huard, Cedric; Bessadet, Marion; Nicolas, Emmanuel; Veyrune, Jean-Luc



Goserelin Implant  


... as an implant to be inserted with a syringe subcutaneously (under the skin) in your stomach area ... written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as ...


Hip Implants  


... advances in the design, construction, and implantation of artificial hip joints, resulting in a high percentage of ... number of measurements to ensure proper prosthesis selection, limb length, and hip rotation. After making the incision, ...


Carmustine Implant  


Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of cancerous brain tumor). Carmustine is in a class of medications called alkylating agents. It works by slowing or stopping ...


Prosthodontic rehabilitation of malpositioned implants after ameloblastoma followed by mandibulectomy and costal bone graft: a clinical report.  


This clinical report describes the rehabilitation with costal bone graft reconstruction and 3 implants of a patient with a partial mandibular defect as a result of a partial mandibulectomy due to ameloblastoma of the left mandible. Due to the altered shape of the graft bone, the implants were malpositioned in the buccolingual plane. The prosthodontic rehabilitation was successfully completed by using an implant-supported milled bar combined with telescopic crown-retained dentures. This tooth implant-supported prosthesis successfully restored function and esthetics. Aspects that deal with the repair of the buccal soft tissues are discussed. PMID:23287980

Wang, Wei; Mao, Cai-Yun; Gu, Xin-Hua



Changes in overnight arterial oxygen saturation after mandibular setback.  


Mandibular setback reduces space in the pharyngeal airway, and it has been suggested that it might induce sleep-disordered breathing. We report on its effects on space in the pharyngeal airway and respiratory function during sleep. We studied 78 patients (29 men and 49 women) in whom skeletal class III malocclusions had been corrected. The mean (range) age at operation was 24 (16-38) years and body mass index (BMI) 21.4 (16.1-30 .9)kg/m(2). Morphological changes were evaluated on lateral cephalograms taken three times: preoperatively, a few days postoperatively, and more than 6 months postoperatively. Overnight arterial oxygen saturation (SpO2) was measured by pulse oximetry 6 times: preoperatively, and on days 1, 3, 5, and 7, and 6 months postoperatively; oximetric indices were calculated. Those immediately after mandibular setback were significantly worse than those preoperatively, although they gradually improved. There were positive correlations between BMI and oximetric indices, and little association between changes in mandibular position and oximetric indices. There was no evidence of sleep-disordered breathing 6 months after mandibular setback because most patients adapt to the new environment for respiratory function during sleep. However, some (particularly obese) patients may develop sleep-disordered breathing just after mandibular setback. In such patients attention should be paid to respiratory function during sleep in the immediate postoperative period, and careful postoperative follow-up is needed. PMID:22853977

Kobayashi, Tadaharu; Funayama, Akinori; Hasebe, Daichi; Kato, Yusuke; Yoshizawa, Michiko; Saito, Chikara



Endosseous implant placement in conjunction with inferior alveolar nerve transposition: a report of an unusual complication and surgical management.  


Inferior alveolar nerve transposition and placement of endosseous implants is one of the treatment options for patients with an edentulous posterior mandible with inadequate bone height superior to the inferior alveolar canal. The possible complications associated with this technique include prolonged neurosensory disturbances, infection, and pathologic fracture. This report presents the surgical management of a patient who sustained a mandibular fracture after inferior alveolar nerve transposition for the placement of 3 endosseous implants. PMID:18416424

Luna, Anibal H B; Passeri, Luis A; de Moraes, Márcio; Moreira, Roger W F


Altered sensation caused by peri-implantitis: a case report.  


Frequently reported is a case wherein a lesion caused by periodontitis or periapical lesion in a natural tooth enlarged, invaded the inferior alveolar nerve canal, and induced paresthesia. Cases wherein paresthesia occurred because of peri-implantitis have been rarely reported. The patient in this case report had experienced transient paresthesia after implant placement and recovered normal sensation 3 months later. Thirteen years later, this patient visited the authors' hospital with paresthesia in the same region because the peri-implantitis progressed to the apex of the implant. One week after removal of the implant, sense recovery and pain relief started, and 15 days after removal, the paresthesia and pain completely disappeared. For patients who experience transient paresthesia and recovery owing to nerve damage caused by the placement of an implant in the mandibular molar or premolar area, or in patients in whom the implant is close to the inferior alveolar nerve canal or the mental nerve, the spread of inflammation caused by peri-implantitis can induce paresthesia. PMID:22749709

Kim, Jong-Eun; Shim, Ji-Suk; Huh, Jung-Bo; Rim, Jae-Suk; Lee, Jeong-Yol; Shin, Sang-Wan



Correlation of panoramic radiography and cone beam CT findings in the assessment of the relationship between impacted mandibular third molars and the mandibular canal  

PubMed Central

Objectives The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images. Methods The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated. Results Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05). Conclusion Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case.

Neves, F S; Souza, T C; Almeida, S M; Haiter-Neto, F; Freitas, D Q; Boscolo, F N



Osteochondroma of mandibular condyle: A clinic-radiographic correlation  

PubMed Central

Osteochondroma (OC) of temporo mandibular joint is a rare, slow growing, benign tumor that causes a progressive enlargement of the condyle, usually resulting in facial asymmetry, temporo mandibular joint (TMJ) dysfunction, limited mouth opening and malocclusion. Pain is rarely associated with this tumor. OC is composed of cartilaginous and osseous tissues. Radiographically, there is unilaterally enlarged condyle usually with an exophytic outgrowth of the tumor from the condylar head. We present a rare case of osteochondroma of right mandibular condyle in a 45-year-old male who reported with painless swelling over TMJ area and progressive limited mouth opening. Panoramic radiograph and computed tomography (CT) was performed for better evaluation of the pathological condition. This paper describes the clinico-radiographic features and differential diagnosis of OC.

More, Chandramani B.; Gupta, Swati



Mandibular fracture and necrotizing sialometaplasia in a rabbit.  


A 7-mo-old female New Zealand white rabbit presented with hemorrhage of the gingiva surrounding a loose lower right incisor. Antemortem conventional radiographs revealed only a small bone fragment adjacent to the left mandible's body. In light of a provisional diagnosis of mandibular fracture, the rabbit was euthanized. Postmortem radiographs of the disarticulated mandible demonstrated mandibular symphyseal fracture and comminuted fracture of the ramus and body of the left mandible. According to histopathology, the left submandibular salivary gland had necrotizing sialometaplasia, a nonneoplastic condition of the salivary glands that is caused by ischemic infarction. Although rabbits have been used as animal models of mandibular fracture and necrotizing sialometaplasia, no nonexperimental case of such conditions had been reported previously. PMID:23561940

Villano, Jason S; Cooper, Timothy K



Gene expression during osteogenic differentiation in mandibular condyles in vitro  

PubMed Central

The cartilagenous tissue of mandibular condyles of newborn mice contains progenitor cells as well as young and mature chondrogenic cells. During in vitro cultivation of the tissue, progenitor cells undergo osteogenic differentiation and form new bone (Silbermann, M., D. Lewinson, H. Gonen, M. A. Lizarbe, and K. von der Mark. 1983. Anat. Rec. 206:373-383). We have studied the expression of genes that typify osteogenic differentiation in mandibular condyles during in vitro cultivation. RNAs of the genes for collagen type I, osteonectin, alkaline phosphatase, and bone gla protein were sequentially expressed in progenitor cells and hypertrophic chondrocytes during culture. Osteopontin expression peaked in both the early and the late phase of the differentiation process. The data indicate a distinct sequence of expression of osteoblast-specific genes during osteogenic differentiation and new bone formation in mandibular condyles.



Evaluation of optimal taper of immediately loaded wide-diameter implants: a finite element analysis.  


This study aimed to evaluate the effects of different tapering angles of an immediately loaded wide-diameter implant on the stress/strain distribution in bone and implant after implant insertion in healed or fresh molar extraction sockets. A total of 10 finite element (FE) implant-bone models, including 8.1-mm diameter implant, superstructure, and mandibular molar segment, were created to investigate the biomechanical behavior of different implant taper angles in immediate and delayed placement conditions. The degrees of implant taper ranged from 2° to 14°, and the contact conditions between the immediately loaded implants and bone were set with frictional coefficients (?) of 0.3 in the healed models and 0.1 in the extracted models. Vertical and lateral loading forces of 189.5 N were applied in all models. Regardless of the degree of implant tapering, immediate loading of wide-diameter implants placed in molar extraction sockets generated higher stress/strain levels than implants placed in healed sockets. In all models, the von Mises stresses and strains at the implant surfaces, cortical bone, and cancellous bone increased with the increasing taper angle of the implant body, except for the buccal cancellous bone in the healed models. The maximum von Mises strains were highly concentrated on the buccal cortical struts in the extracted models and around the implant neck in the healed models. The maximum von Mises stresses on the implant threads were more concentrated in the non-tapered coronal part of the 11° and 14° tapered implants, particularly in the healed models, while the stresses were more evenly dissipated along the implant threads in other models. Under immediate loading conditions, the present study indicates that minimally tapered implants generate the most favorable stress and strain distribution patterns in extracted and healed molar sites. PMID:21905902

Atieh, Momen A; Shahmiri, Reza A



Total autogenous mandibular reconstruction using virtual surgical planning.  


Free fibula transfer has become the workhorse in mandibular reconstruction. Total mandibular reconstruction is an uncommon procedure with added complexity. Numerous techniques have been described for such reconstruction, many requiring a temporomandibular joint prosthesis. We present a novel method where simultaneous bilateral free fibula transfer utilizing preoperative virtual surgical planning was used to produce a total autogenous reconstruction. The virtual surgical planning allows to effectively quantify the bone stock required preoperatively and facilitates intraoperative modeling of the fibula. Therefore, a more anatomically correct reconstruction is obtained resulting in improved functional and aesthetic outcomes. PMID:22976686

Winters, Ryan; Saad, Adam; Beahm, Donald David; Wise, Matthew Whitten; St Hilaire, Hugo



Zoledronate reverses mandibular bone loss in osteoprotegerin-deficient mice  

Microsoft Academic Search

Summary  To characterize the changes in osteoprotegerin-deficient (OPG?\\/?) mice mandibles and the possible mandibular bone loss prevention\\u000a by zoledronate. This preventive effect in the mandible differed from that in the proximal tibia and was independent of the\\u000a OPG pathway.\\u000a \\u000a \\u000a \\u000a Introduction  The study aimed to characterize both the changes in the mandible in osteoprotegerin-deficient (OPG?\\/?) mice and possible mandibular bone loss prevention by

Z.-F. Sheng; K. Xu; Y.-L. Ma; J.-H. Liu; R.-C. Dai; Y.-H. Zhang; Y.-B. Jiang; E.-Y. Liao



How will mandibular third molar surgery affect mandibular second molar periodontal parameters?  

PubMed Central

Background: Several conflicting findings have been published in the previous literature regarding the effects of impacted third molar surgery on the periodontal parameters of the adjacent second molar; some authors have shown improvement of periodontal health distal to the adjacent second molar, whilst others have demonstrated loss of attachment level (AL) and reduction of alveolar bone height. The purpose of this study was to evaluate the changes in periodontal health parameters distal to the adjacent second molar following extraction of an impacted third molar. Materials and Methods: Out of 50 patients participated in the study, 42 patients completed the study. The mean age of the sample was 20.9 (range, 18-25) years. All teeth were mesioangular impacted mandibular third molars categorized at C1 class based on the Pell and Gregory classification. All surgeries were performed by one surgeon and the same surgeon recorded the pre-operative and post-operative measurements of probing depth (PD) and AL on the distobuccal aspect of the second molars. Data analysis were carried out with the SPSS software (version 19), using the paired-samples t-test and one sample t-test. Results: Surgical extraction of impacted mandibular third molar resulted in a significant increase of PD on the distobuccal aspect of the second molars, whereas AL was decreased significantly after surgery (P < 0.05). Conclusion: Unlike plenty of researches that have shown improvement of periodontal parameters of the second molar after extraction of impacted third molar, our study showed a significant increase in PD at the distal aspect of the second molar. Further follow-up on clinical and radiological parameters are required for more profound understanding of the long-term effects of third molar extraction on the periodontal parameters of the adjacent second molar.

Tabrizi, Reza; Arabion, Hamidreza; Gholami, Mehdi



Case presentation of florid cemento-osseous dysplasia with concomitant cemento-ossifying fibroma discovered during implant explantation.  


A 39-year-old African American woman presented for treatment of a symptomatic mandibular right first molar with a large, periapical radiolucency. After initial attempts at endodontic therapy, this tooth was ultimately extracted owing to unabated symptoms. The extraction site underwent ridge preservation grafting, implant placement, and restoration. After 26 months of implant function, the patient returned with clinical symptoms of pain, buccal swelling, and the sensation of a "loose" implant. This case report details a diagnosis of 2 distinct disease entities associated with the implant site, a cemento-ossifying fibroma and florid cemento-osseous dysplasia of the mandible. This diagnosis was determined from clinical, surgical, radiographic, and histopathologic evidence after biopsy and removal of the previously osseointegrated implant following postinsertion failure by fibrous encapsulation. Before implant therapy, it is essential to conduct a thorough radiographic evaluation of any dental arch with suspected bony lesions to prevent implant failure. PMID:22858018

Gerlach, Robert C; Dixon, Douglas R; Goksel, Tamer; Castle, James T; Henry, Walter A



Mandibular corpus bone strain in goats and alpacas: Implications for understanding the biomechanics of mandibular form in selenodont artiodactyls  

PubMed Central

The goal of this study is to clarify the functional and biomechanical relationship between jaw morphology and in vivo masticatory loading in selenodont artiodactyls. We compare in vivo strains from the mandibular corpus of goats and alpacas to predicted strain patterns derived from biomechanical models for mandibular corpus loading during mastication. Peak shear strains in both species average 600–700 µ? on the working side and approximately 450 µ? on the balancing side. Maximum principal tension in goats and alpacas is directed at approximately 30° dorsocaudally relative to the long axis of the corpus on the working side and approximately perpendicular to the long axis on the balancing side. Strain patterns in both species indicate primarily torsion of the working-side corpus about the long axis and parasagittal bending and/or lateral transverse bending of the balancing-side corpus. Interpretation of the strain patterns is consistent with comparative biomechanical analyses of jaw morphology suggesting that in goats, the balancing-side mandibular corpus is parasagittally bent whereas in alpacas it experiences lateral transverse bending. However, in light of higher working-side corpus strains, biomechanical explanations of mandibular form also need to consider that torsion influences relative corpus size and shape. Furthermore, the complex combination of loads that occur along the selenodont artiodactyl mandibular corpus during the power stroke has two implications. First, added clarification of these loading patterns requires in vivo approaches for elucidating biomechanical links between mandibular corpus morphology and masticatory loading. Second, morphometric approaches may be limited in their ability to accurately infer masticatory loading regimes of selenodont artiodactyl jaws.

Williams, Susan H; Vinyard, Christopher J; Wall, Christine E; Hylander, William L



Ion Implant  

NSDL National Science Digital Library

This website includes an animation which illustrates the ion implant process. Objective: Name the three common dopants used in implantation processes and explain the process of generating an ion beam from source to wafer. You can find this animation under the heading "Process & Equipment III." This simulation is from Module 026 of the Process & Equipment III Cluster of the MATEC Module Library (MML). To view other clusters or for more information about the MML visit



Unique and reliable rat model for the assessment of cell therapy: bone union in the rat mandibular symphysis using bone marrow stromal cells.  


Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre-existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non-healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro-computed tomography (micro-CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture-expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23255518

Yagyuu, Takahiro; Kirita, Tadaaki; Hattori, Koji; Tadokoro, Mika; Ohgushi, Hajime



Cochlear Implants  


... In With a Cochlear Implant This type of hearing loss is sensorineural , which means there is damage to the tiny hair cells in the part of the inner ear called the cochlea. Because of this damage, ... or “cured” hearing. It does, however, allow for the perception of ...


[Reduction gonioplasty for the prominent mandibular angle. Report of 38 cases].  


The one-stage curved osteotomy of the mandibular angle without resection of the masseter was used for 38 patients suffering from prominent mandibular angle from december 1996 to november 1997 at our department of plastic and cranio-maxillo-facial surgery. The preoperative strategy and surgical procedure are described. These 38 cases had a low rate of complications and usually good cosmetic results. Technical refinements that have improved the results are analyzed. At the present time the one-stage curved osteotomy of the mandibular angle is a simple and more reliable method for the surgical correction of the prominent mandibular angle, which is preferred by us to the other techniques: resection of the masseter alone or with straight cutting of the mandibular angle, simple straight cutting of the mandibular angle, multistaged osteotomy of the mandibular angle. PMID:11534448

Gui, L; Athmani, B; Zhang, Z Y; Ten, L



Mandibular rest position and electrical activity of the masticatory muscles  

Microsoft Academic Search

Statement of problem. The determination of a correct vertical dimension of occlusion is a critical procedure in clinical dentistry.Purpose. The objectives of this study were to analyze the relation between mandibular rest position and electrical activity of masticatory muscles and to compare clinical and electromyographic rest position in subjects with different vertical facial morphologic features.Material and methods. Clinical rest position

Ambra Michelotti; Mauro Farella; Stefano Vollaro; Roberto Martina



Perineural infiltration of the inferior alveolar nerve in mandibular ameloblastomas.  


Our aim was to evaluate the histological association of mandibular solid and multicystic ameloblastoma with the inferior alveolar nerve, both in situ and in segments of the nerve that had been removed separately, to assess the feasibility of preserving the nerve during resection of mandibular ameloblastomas. In this prospective histological examination of 13 resected hemimandibulectomy specimens, we studied the proximity of tumour cells to the inferior alveolar nerve. In group 1 (n=8) this association was examined with the nerve still within the mandibular segment after resection, while in group 2 (n=5) the nerve was removed from the resected tumour and examined separately. Perineural and intraneural involvement of the ameloblastoma with the nerve was confirmed in 5 cases in group 1 and 2 cases in group 2. Tumour cells abutted the nerve directly in group 1. In group 2 tumour was removed with, and found within, the nerve. On this evidence we cannot recommend preservation of the inferior alveolar nerve during operation for large, advanced, mandibular ameloblastomas. PMID:23473884

Engelbrecht, Hanlie; Meer, Shabnum; Kourie, Jeff F



The History of the Christensen Mandibular and TMJ Alloplastic Reconstruction  

Microsoft Academic Search

Objective. To inform the reader of the history of the Christensen mandibular and temporomandibular joint devices and the usefulness of the more recent generation of devices in the typical and atypical temporomandibular joint patient. Methods. The larger amount of data will involve the younger female patient who represents some 88% to 90% of patients with early to late TMJ disease

Robert W. Christensen


Treatment of mandibular osteoradionecrosis by cancellous bone grafting  

Microsoft Academic Search

Purpose: This study was undertaken to evaluate a new method in the treatment of mandibular Osteoradionecrosis.Patients and Methods: Eight patients, seven male and one female, with a mean age of 64 years (range, 43 to 67 years), suffering from Osteoradionecrosis of the mandible, two bilaterally and six unilaterally, were treated. Five initially had hyperbaric oxygen (HBO) followed by sequestrectomy, and

Sven Jisander; Björn Grenthe; Lars Salemark



Refinement in aesthetic contouring of the prominent mandibular angle  

Microsoft Academic Search

Oriental women, in general, greatly desire a more delicate and feminine facial shape. This can be obtained by contouring the prominent mandibular aangles that give a strong, masculine image. Western authors regarded masseteric muscular hypertrophy the main cause of a square facial appearance, so they usually corrected it by partially excising the masseter muscle. In the authors' view, a square

Se-Min Baek; Rong-Min Baek; Myoung-Soo Shin



Interocclusal Clearance during Speech and in Mandibular Rest Position  

Microsoft Academic Search

Background and Aim: The interocclusal clearance during speech and in mandibular rest position shows an interindividual variation and influences the stability of prosthodontic reconstruction or orthodontic therapy, especially in patients with deep bite or cover-bite. Exact determination of the vertical dimension, not always a simple matter in practice, is controversially discussed with respect to the methodology. The aim of the

Birgit Meier; Olaf Luck; Winfried Harzer



Unfavorable results and their resolution in mandibular contouring surgery  

Microsoft Academic Search

Since the development of mandibular contouring surgery, there have been many unfavorable results due to technical reasons. Those results include asymmetry, undercorrection, overcorrection, and an incorrect contour line. Over three years the authors have analyzed 19 cases of unfavorable results and found the following: (1) There have been 7 cases of undercorrection, 5 cases of asymmetry, 5 cases of incorrect

Doo Byung Yang; Hong Shick Song; Chul Gyoo Park



Ultrastructure of the platypus and echidna mandibular glands.  


The secretory units of the platypus and echidna mandibular glands consist of a single serous cell type. Secretory granules within the cells of the platypus mandibular gland stained intensely with the periodic acid-Schiff staining procedure but failed to stain with Alcian Blue, suggesting the granules contained neutral glycoproteins. Secretory granules within the mandibular glands of the echidna failed to stain with the methods used indicating little if any glycoprotein was associated with the secretory granules. Ultrastructurally, secretory granules of the platypus mandibular gland were electron dense with a central core of less electron-dense material and were membrane bound. In contrast, those of the echidna presented a lamellated appearance and also were limited by a membrane. These secretory granules appeared to form as a result of concentric layering of lamellae within cisternae of the Golgi membranes. The intralobular ductal system of the platypus was more extensively developed than that of the echidna. The striated ducts of both species were characterized by elaborate infoldings of the basolateral plasmalemma and an abundance of associated mitochondria. PMID:21671995

Krause, W J



Use of Intraosseous Metal Appliances in Fixation of Mandibular Fractures.  

National Technical Information Service (NTIS)

When it is clinically determined that unfavorable stress might be placed on mandibular fracture segments, use of a transosseous splint or plate may be considered. In this study on dogs, intraosseous use of crossed wire alone for reduction and fixation of ...

E. J. Messer D. E. Hayes P. J. Boyne



Aneurysmal Bone Cyst located in the Mandibular Condyle  

Microsoft Academic Search

A rare case of aneurysmal bone cyst (ABC) located in the mandibular condyle in a 10-year-old boy is presented. The patient came to our attention for a sudden swelling in the right temporomandibular region, the mouth opening was not reduced. A rapid growing mass, depicting soft tissue invasion, in the right condyle of the mandible was found. Clinically and radiographically

Sandro Pelo; Giulio Gasparini; Roberto Boniello; Alessandro Moro; Pier Francesco Amoroso



Hemisection as an alternative treatment for vertically fractured mandibular molars.  


Hemisection of mandibular molars may be a viable treatment option when vertical root fracture has occurred and the other root is healthy. This article discusses a case that presents the techniques involved in hemisection and restoration of the remaining tooth root. PMID:16494100

Kurtzman, Gregori M; Silverstein, Lee H; Shatz, Peter C



Radiographic evaluation of mandibular third molar eruption space  

Microsoft Academic Search

Objective. The purpose of this study was to investigate variables in third molar and arch dimensions among subjects with impacted and erupted mandibular third molars. Study Design. Standardized panoramic radiographs were taken for 134 subjects (60 males and 74 females with 213 third molars) with an average age of 19.8 years. For the impacted group, only those who had mesioangular

Faiez N. Hattab; Elham S. J. Abu Alhaija



Genetic Variation in Myosin 1H Contributes to Mandibular Prognathism  

PubMed Central

Introduction Several candidate loci have been suggested as influencing mandibular prognathism (1p22.1, 1p22.2, 1p36, 3q26.2, 5p13-p12, 6q25, 11q22.2-q22.3, 12q23, 12q13.13, and 19p13.2). The goal of this study was to replicate these results in a well-characterized homogeneous sample set. Methods Thirty-three single nucleotide polymorphisms spanning all candidate regions were studied in 44 prognathic and 35 Class I subjects from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository. The 44 mandibular prognathism subjects had an average age of 18.4 years, 31 were females and 13 males, and 24 were White, 15 African American, two Hispanic, and three Asian. The 35 Class I subjects had an average age of 17.6 years, 27 were females and 9 males, and 27 were White, six African Americans, one Hispanic, and two Asian. Skeletal mandibular prognathism diagnosis included cephalometric values indicative of Class III such as ANB smaller than two degrees, negative Witts appraisal, and positive A–B plane. Additional mandibular prognathism criteria included negative OJ and visually prognathic (concave) profile as determined by the subject's clinical evaluation. Orthognathic subjects without jaw deformations were used as a comparison group. Mandibular prognathism and orthognathic subjects were matched based on race, sex and age. Genetic markers were tested by polymerase chain reaction using TaqMan chemistry. Chi-square and Fisher exact tests were used to determine overrepresentation of marker allele with alpha of 0.05. Results An association was unveiled between a marker in MYO1H (rs10850110) and the mandibular prognathism phenotype (p=0.03). MYO1H is a Class-I myosin that is in a different protein group than the myosin isoforms of muscle sarcomeres, which are the basis of skeletal muscle fiber typing. Class I myosins are necessary for cell motility, phagocytosis and vesicle transport. Conclusions More strict clinical definitions may increase homogeneity and aid the studies of genetic susceptibility to malocclusions. We provide evidence that MYO1H may contribute to mandibular prognathism.

Tassopoulou-Fishell, Maria; Deeley, Kathleen; Harvey, Erika M.; Sciote, James; Vieira, Alexandre R.



Implant Chips  

NSDL National Science Digital Library

A group of eight people, including all members of one Florida family, had an implant chip, roughly the size of a grain of rice, injected under their skin on Friday, May 10. Manufactured by Applied Digital Solutions (ADS), the chips store a special identification number that enables the retrieval of personal and medical information. In the event of a medical emergency, a special handheld scanner activates the dormant digital implant, which provides identification data with which medical personnel can query ADS's database, the location of the patient's medical records. Alzheimer's patients seem to be the most promising market for this technology, even though other people, like the Florida family, hope to benefit from it as well. Another product that ADS offers is called Digital Angel, a wearable global positioning system (GPS) device that, among other things, can track in real time the wearer's physical movements. In the future, ADS is planning to release a product that will utilize both of these technologies: an implanted GPS-enabled chip. Unlike VeriChip, though, the GPS-enabled implant would require Food and Drug Administration (FDA) approval, meaning the US market won't see its introduction until after FDA testing. Many organizations, ranging from privacy advocates to religious groups, have already denounced VeriChip and its eventually successors, associated them with "Big Brother" and the biblical "Mark of the Beast."To read about the eight people that received their implants, look at the first and second sites, articles from the Los Angeles Times and Miami Herald respectively. For a non-US perspective, view the news story posted by the British Broadcasting Company (BBC). The fourth site, an extensive analysis of the subject from ABC News, should give readers a broader understanding of implanted chips and their potential uses. Two sites from ADS are next -- VeriChip's product pages and the press release that details a FDA's decision regarding VeriChip in April, 2002. Finally, the last two sites give more information on Digital Angel and a sample of GPS technology already in use.

Schroeder, Ted.



Facial and oral reconstruction following trauma and failed chin implant: a case report.  


Functional and esthetic reconstruction of a patient with microgenia who sustained traumatic injury was successfully accomplished using Brånemark System osseointegrated implants (Nobel Biocare USA, Inc., Yorba Linda, CA) to support a permanent dental prosthesis following mechanical and biologic reconstruction of the anterior mandible and chin. A 25-year-old glycine chin implant previously used for facial esthetic enhancement had eroded the anterior cortical plate and migrated through the medullary bone, compressing the periosteum into the apex of the anterior tooth roots. Further destruction of the lingual cortex with risk of fracture was imminent. After removal of the chin implant, a cancellous bone graft was held in place with a titanium mesh frame. The prosthetic rehabilitation consisted of two phases of mandibular implant placement followed by the construction of a porcelain-fused-to-gold implant-supported fixed prosthesis, restoring the occlusal vertical dimension as well as appropriate lip support. Restoration of function was superior to the pretreatment condition. PMID:16160565

Balshi, Thomas J; Wolfinger, Glenn J; Pryszlak, Maria Claudia; Balshi, Stephen F



Optimal restoration of dental esthetics and function with advanced implant-supported prostheses: a clinical report.  


For more than 25 years, computer-aided design and computer-aided manufacturing (CAD/CAM) technology has been used in implant restorative dentistry. Today this technology offers a means of milling titanium frameworks that fit dental implants accurately. This report presents a restoratively driven protocol employing advanced implant restorative and surgical techniques. Treatment of a patient with advanced periodontitis with extensive loss of hard and soft tissues is presented. After extraction of the patient's remaining hopeless teeth, dental implants were placed, along with interim, fixed-margin abutments and abutment protection caps. Two days later, acrylic resin fixed-interim prostheses restored the patient's esthetics and partial masticatory function. After implant osseointegration, maxillary, and mandibular frameworks for definitive prostheses were milled from Ti alloy, using one specific CAD/CAM technology. The benefits of this technology are also discussed. PMID:22372489

Meulen, Peter van der; Linden, Wynand van der; Eeden, Ronnie van



Penile Implants  

Microsoft Academic Search

Effective penile implants were introduced in the early 1970s and have provided a predictable and reliable treatment of erectile\\u000a dysfunction. They can be placed in almost all circumstances in which more conservative treatments have been ineffective or\\u000a are contraindicated. Manufacturers of these devices have improved their functioning and durability, and repair rates are low\\u000a when compared with other mechanical products.

Steven K. Wilson; John J. Mulcahy


Computed tomography-guided implant surgery for dental rehabilitation in mandible reconstructed with a fibular free flap: description of the technique  

Microsoft Academic Search

The fibular free flap, with or without a cutaneous component, is the gold standard for reconstructing mandibular defects. Dental prosthetic rehabilitation is possible this way, even if the prosthesis-based implant is still a challenge because of the many anatomical and prosthetic problems. We think that complications can be overcome or reduced by adopting the new methods of computed tomography (CT)-assisted

Giacomo De Riu; Silvio Mario Meloni; Milena Pisano; Olindo Massarelli; Antonio Tullio


Developing a New Dental Implant Design and Comparing its Biomechanical Features with Four Designs  

PubMed Central

Background: As various implant geometries present different biomechanical behaviors, the purpose of this work was to study stress distribution around tapered and cylindrical threaded implant geometries using three-dimensional finite element stress analysis. Methods: Seven implant models were constructed using Computer Assisted Designing system. After digitized models of mandibular section, the crowns were created. They were combined with implant models, which were previously imported into CATIA software. The combined solid model was transferred to ABAQOUS to create a finite element meshed model which was later analyzed regarding the highest maximum and minimum principal stresses of bone. Results: For all models, the highest stresses of cortical bone were located at the crestal cortical bone around the implant. Threaded implants, triangular thread form and taper body form showed a higher peak of tensile and compressive stress than non-threaded implants, square thread form and straight body form, respectively. A taper implant with triangular threads, which is doubled in the cervical portion of the body, had a significantly lower peak of tensile and compressive stress in the cortical bone than straight/taper triangular or square threaded implant forms. Conclusion: For the investigation of bone implant interfacial stress, the non-bonded state should be studied too. Confirmative clinical and biological studies are required in order to benefit from the results of this study.

Rismanchian, Mansour; Birang, Reza; Shahmoradi, Mahdi; Talebi, Hassan; Zare, Reza Jabar



Growth changes of the mandibular body with eruption of mandibular third molars: analysis of anatomical morphometry and quantitative bone mineral content by using radiography.  


This study aimed to analyze growth changes in mandibular body morphology and quantitative bone mineral content (QBMC) with eruption of mandibular third molars (M3s) and the relationship between those variables and posterior mandibular body length. Linear and angular measurements were conducted using standard lateral radiographs of 37 dried mandibles in Hellman's dental developmental stages IVA (14 specimens) to VA (23 specimens). Cortical and trabecular basal bone mineral contents (CBMC and TBMC) in the mandible were expressed in millimeter titanium equivalent values using a titanium step wedge. The largest significant change in the mandibular body morphology was an increase in the horizontal dimension (M2DP'-Go': 7.59mm), followed by vertical dimension - total height of the mandibular body (THOMB: 4.96mm) and mandibular cortical width (MCW: 1.22mm). The gonial angle (GA) decreased significantly by 6.72° between stages IVA and VA. The mandibular cortical index (MCI) was classified only as C1 or C2 in each stage. Among 4 types of line profile, types 1 and 2 were most commonly observed in both stages. Mean values for CBMC and TBMC increased significantly between stages IVA and VA. Posterior mandibular body length (MeF'-Go') correlated positively with M2DP'-Go', THOM, MCW, and CBMC (r=0.816, 0.698, 0.595, and 0.507), respectively and negatively with GA (r=-0.582). These results demonstrated that the morphological changes in the posterior mandibular body and the QBMC increased significantly with M3 eruption, while the GA became significantly smaller. The posterior mandibular body length had a linear correlation with these variables. PMID:23031389

Ogawa, Takahiro; Osato, Shigeo



Effect of defective collagen synthesis on epithelial implant interface: lathyritic model in dogs. An experimental preliminary study.  


Peri-implant mucosa is composed of 2 compartments: a marginal junctional epithelium and a zone of connective tissue attachment. Both structures consist mainly of collagen. Lathyrism is characterized by defective collagen synthesis due to inhibition of lysyl oxidase, an enzyme that is essential for interfibrillar collagen cross-linking. The lathyritic agent beta-aminoproprionitrile (?-APN) is considered a suitable agent to disrupt the connective tissue metabolism. Therefore, the purpose of this study was to assess the effect of defective connective tissue metabolism on epithelial implant interface by using ?-APN created chronic lathyrism in the canine model. Two 1-year-old male dogs were included in this study. A ?-APN dosage of 5 mg/0.4 mL/volume 100 g/body weight was given to the test dog for 10 months, until lathyritic symptoms developed. After this, the mandibular premolar teeth (p2, p3, p4) of both dogs were atraumatically extracted, and the investigators waited 3 months before implants were placed. In the test dog, 3 implants were placed in the left mandible, and 2 implants were placed in the right mandible. In the control dog, 2 implants were placed in the left mandibular premolar site. The dogs were sacrificed 10 months after healing. Peri-implant tissues obtained from the dogs were examined histomorphologically and histopathologically. Bone to implant contact (BIC) values and bone volumes (BV) were lower in the lathyritic group compared to the control group; however, no statistical significance was found. Significant histologic and histomorphometric changes were observed in peri-implant bone, connective tissue, and peri-implant mucosal width between test and control implants. Defective collagen metabolism such as lathyrism may negatively influence the interface between implant and surrounding soft tissue attachment. PMID:20662666

Cengiz, Murat Inanç; Kirtilo?lu, Tu?rul; Acikgoz, Gökhan; Trisi, Paolo; Wang, Hom-Lay



Inferior alveolar nerve injuries associated with mandibular fractures.  


The study evaluates the incidence of inferior alveolar nerve injuries in mandibular fractures, the duration of their recovery, and the factors associated with them. Fifty-two patients with mandibular fractures involving the ramus, angle, and body regions were included in this study; the inferior alveolar nerve was examined for neurological deficit posttraumatically using sharp/blunt differentiation method, and during the follow-up period the progression of neural recovery was assessed. The incidence of neural injury of the inferior alveolar nerve was 42.3%, comminuted and displaced linear fractures were associated with higher incidence of inferior alveolar nerve injury and prolonged recovery time, and recovery of inferior alveolar nerve function occurred in 91%.Fractures of the mandible involving the ramus, angle, and body regions, and comminuted and displaced linear fractures are factors that increase the incidence of inferior alveolar nerve injuries. Missile injuries can be considered as another risk factor. PMID:23147318

Bede, Salwan Yousif Hanna; Ismael, Waleed Khaleel; Al-Assaf, Dhuha A; Omer, Saad Salem



Biomechanical Configurations of Mandibular Transport Distraction Osteogenesis Devices  

PubMed Central

Mandibular bone transport (MBT) distraction osteogenesis devices are used for achieving reconstruction of mandibular defects in a predictable way, with few complications, less complexity than other alternative surgical procedures, and minimal tissue morbidity. However, selection of appropriate MBT device characteristics is critical for ensuring both their mechanical soundness and their optimal distraction function for each patient's condition. This article assesses six characteristics of currently available MBT devices to characterize their design and function and to classify them in a way that assists the selection of the best device option for each clinical case. In addition, the present work provides a framework for both the biomechanical conception of new devices and the modification of existing ones.

Zapata, Uriel; Elsalanty, Mohammed E.; Dechow, Paul C.



Refinement in aesthetic contouring of the prominent mandibular angle.  


Oriental women, in general, greatly desire a more delicate and feminine facial shape. This can be obtained by contouring the prominent mandibular angles that give a strong, masculine image. Western authors regarded masseteric muscular hypertrophy the main cause of a square facial appearance, so they usually corrected it by partially excising the masseter muscle. In the authors' view, a square facial appearance in the Oriental is not due to masseteric hypertrophy but to a posterior projection and lateral flaring of the mandibular angle. However, it is sometimes difficult to make the square face narrow and ovoid by using only the conventional curved-angle osteotomy. We divided patients, whose chief complaint was a square facial appearance, into three groups after clinical, photographic, and radiographic evaluation. We applied different contouring methods to each of the three groups and obtained cosmetically improved facial appearance in both lateral and frontal views. PMID:7976763

Baek, S M; Baek, R M; Shin, M S



The split rib bundle graft in mandibular reconstruction.  


This article describes a modified technique for the use of free non-vascularized split ribs (bound together in the form of a tight bundle), to reconstruct different types of mandibular defects. Experience gained over the last 4 years in treating 38 patients with different pathological lesions is presented. The procedure, carried out simultaneously with bone resection proved to be highly effective in providing mesio-distal spanning of the defect, adequate mandibular height as well as bucco-lingual thickness. This technique utilizes the different theories of osteogenesis: (a) from the periosteal cells, (b) from the transplanted living osteocytes and from (c) stimulating host mesenchymal cells to form new bone by bone induction. The surgical technique, results and conclusions are presented in this report. PMID:1464680

el-Sheikh, M M; Zeitoun, I M; Medra, A M



A rare case of dens invaginatus in a mandibular canine.  


Dens invaginatus (dens in dente) is a common dental anomaly with a reported prevalence of between 0.04% and 10%. It typically affects permanent maxillary lateral incisors, central incisors and premolars. These developmental lesions are less common in mandibular teeth and are extremely rare in canines and molars. This report describes a rare case of dens invaginatus (Oehlers type II) in a permanent mandibular canine. The tooth was mature with a closed apex and showed apical pathosis. The tooth was treated endodontically using a non-surgical technique with hand endodontic files, and then followed up after a period of 8 months. A follow-up radiograph showed some healing of the lesion. PMID:20666755

George, Roy; Moule, Alexander J; Walsh, Laurence J



Free greater omental flap for treatment of mandibular osteoradionecrosis  

SciTech Connect

Osteoradionecrosis can involve the mandible following radical irradiation for treatment of oral cavity cancer. The radionecrosis of the mandible is often associated with severe intractable pain, local or extensive deformity, including pathologic fracture, orocutaneous fistula formation, and frequent loss of function. Treatment has ranged from analgesia and antibiotics to hyperbaric oxygen treatments to local or extensive sequestrectomies with partial or total mandibulectomy and restoration of tissue losses with unirradiated tissue. To our knowledge, this is the first report of the successful use of a free greater omental flap for immediate treatment of mandibular osteoradionecrosis and concomitant reconstruction. We found the omentum to be an excellent vascular bed that rapidly resolved the osteoradionecrosis and pain, promoted healing, and restored mandibular function with minimal discomfort to the patient.

Moran, W.J.; Panje, W.R.



External coaptation of rostral mandibular fractures in calves.  


Six cases of rostral mandibular fracture with considerable displacement were treated successfully by external coaptation. Four cases were simple and two were compound fractures. After xylazine sedation and manual reduction of the fractures, the casting tape was laminated to make a rigid splint below the mandibles and then the splint was secured using the casting tape passing the nasal bridge and cranial and/or caudal to the ears as it encircled the head. During application of the tape, a PVC pipe 25 mm in diameter was held in its jaws to keep the mouth open so that the calf could suckle. Simple rostral mandibular fractures were cured after two weeks of cast immobilisation and compound fractures after about three weeks. This method is easy and non-stressful and provided a good prognosis in the present cases. PMID:22550122

Taguchi, K; Hyakutake, K



Sex differences in mandibular movements during opening and closing  

Microsoft Academic Search

This study evaluated the sex differences in maximum 3-dimensional opening and closing movements. The sample included 29 men (ages, 23-39 years) and 27 women (ages, 23-35 years), who were selected for normal Class I occlusion, temporomandibular function, and skeletal patterns. Condylar (hinge axis) translation and mandibular incisor movements, were recorded with an optoelectric jaw-tracking system; each participant performed 4 maximum

Rodney P. Lewis; Peter H. Buschang; Gaylord S. Throckmorton



Increased Crown-To-Implant Ratio May Not Be a Risk Factor for Dental Implant Failure under Appropriate Plaque Control  

PubMed Central

Objective The aim of this study was to evaluate whether increased crown-to-implant (C/I) ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control. Materials and Methods Five male Beagle-Labrador hybrid dogs (2 years old) were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week). Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically. Result Implant stability quotient (ISQ) increased with time in all 3 groups, without any significant correlation with the C/I value (p>0.05). Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p>0.05). Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control. Conclusion These findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

Okada, Shinsuke; Koretake, Katsunori; Miyamoto, Yasunari; Oue, Hiroshi; Akagawa, Yasumasa



Implantable Medical Devices  


Implantable Medical Devices Updated:May 1,2012 In certain cases, your doctor may prescribe an implantable device to assist your ... maintain the pumping ability of your heart. Implantable Medical Devices Left Ventricular Assist Device (Also known as LVAD) ...


Implant-Supported Denture  


... to implants. A regular denture rests on the gums, and is not supported by implants. An implant- ... supported denture daily to clean the denture and gum area. Just as with regular dentures, you should ...


[Bruxism, temporo-mandibular dysfunction and botulinum toxin].  


Tooth grinding and tooth clenching are unvoluntary mainly nocturnal habits that result in an hypertrophy of masseter and temporalis muscles with an unbalance between opening and closing muscles of the jaw and lead to an alteration of mandibular condyles movements and to hyper pressure in the temporo-mandibular joints (TMJ) which can generate severe pain. Intra muscular injections of botulinum toxin permit to restablish the balance between closing and opening muscles, to relieve pain, to treat masseteric hypertrophy with improvement of face outline and to recover a normal cinetic of temporo-mandibular joints. Moreover, botulinum toxin injections permit to quit habits of tooth grinding and clenching and one single session of injections is curative for 2/3 of the patients. There are no side effects apart from slight diffusion to superficial muscles of the face resulting in a "fixed" smile for about 6 to 8 weeks. So injections of botulinum toxin in masseter and temporalis muscles are an efficient treatment of bruxism and TMJ dysfunction, cheap with no lasting side effect. PMID:12928140

Chikhani, L; Dichamp, J



Marginal mandibular branch of the facial nerve: An anatomical study.  


Smile is one of the most natural and important expressions of human emotion. Man uses his lips mainly to register his emotions. Thus, the slightest asymmetry or weakness around the lips and mouth may transform this pleasant expression into embarrassment and distortion. The circumoral musculature, the major part of which is supplied by the marginal mandibular branch of the facial nerve, is the main factor in this expression. Therefore, an injury to this nerve during a surgical procedure can distort the expression of the smile as well as other facial expressions. This nerve often gets injured by surgeons in operative procedures in the submandibular region, like excision of the submandibular gland due to lack of accurate knowledge of variations in the course, branches and relations. In the present study, 50 facial halves were dissected to study the origin, entire course, termination, branches, muscles supplied by it, its anastomoses with other branches of facial nerve on the same as well as on the opposite side and its relations with the surrounding structures. The marginal mandibular branch of the facial nerve was found superficial to the facial artery and (anterior) facial vein in all the cases (100%). Thus the facial artery can be used as an important landmark in locating the marginal mandibular nerve during surgical procedures. Such a study can help in planning precise and accurate incisions and in preventing the unrecognized severance of this nerve during surgical procedures. PMID:20924452

Batra, Arvinder Pal Singh; Mahajan, Anupama; Gupta, Karunesh



Craniomandibular Disorders and Mandibular Reference Position in Orthodontic Treatment  

PubMed Central

The aim of this paper is to bring into focus the literature on the choice of the mandibular reference position in orthodontic treatment; of a particular reference to this paper is intercuspal position, centric relation position, or therapeutic position. To give a comprehensive account of the literature review on craniomandibular disorders (CMD), we have relied on books and articles using both Google Scholar and PubMed. Selection criteria included a combination of Mesh and type of article. Article classification was made by two authors, using the following structure outline: prevalence of craniomandibular disorders, its etiology and pathophysiology, occlusion and craniomandibular disorders, orthodontic treatment and CMD, and the mandibular reference position in orthodontics. An important conclusion that emerged from the present literature review is that CMD do not seem to be directly related to orthodontic treatment, and their appearance cannot be predicted or prevented by any means. Therefore, orthodontists must adopt a mandibular reference suitable to their patients and which best respects the balance existing in the stomatognathic system.

Bourzgui, Farid; Aghoutan, Hakima; Diouny, Samir



3-D diagnosis-assisted management of anomalous mandibular molar  

PubMed Central

This case report describes the successful non-surgical endodontic management of carious exposed three-rooted mandibular molar with four root canals detected on the pre-operative radiograph taken with 20 degrees mesial angulation and confirmed with a 64-slice helical computed tomography scan-assisted 3-D-reconstructed images. Access cavity shape was modified to locate the extra canal with respect to the distolingual root in the left mandibular first molar. Copious irrigation was accomplished with 5.25% sodium hypochlorite and 17% EDTA. Biomechanical preparation was done using protapers. Calcium hydroxide dressing was done for 1 week. The tooth was obturated using gutta percha and AH 26 root canal sealer, and it was permanently restored with composite. Clinical examination on follow-up visits revealed no sensitivity to percussion and palpation in the left mandibular first molar. Thorough knowledge of root canal variations and use of advanced diagnostic modalities lead to successful non-surgical management of the complex cases.

Mittal, Neelam; Narang, Isha



Root canal morphology of human maxillary and mandibular third molars.  


The anatomy of third molars has been described as unpredictable. However restorative, prosthetic, and orthodontic considerations often require endodontic treatment of third molars in order for them to be retained as functional components of the dental arch. The purpose of this study was to investigate and characterize the anatomy of maxillary and mandibular third molars. One hundred fifty maxillary and 150 mandibular extracted third molars were vacuum-injected with dye, decalcified, and made transparent. The anatomy of the root canal system was then recorded. Seventeen percent of mandibular molars had one root (40% of which contained two canals), 77% had two roots, 5% had three roots, and 1% had four roots. Teeth with two roots exhibited highly variable canal morphology, containing from one to six canals, including 2.2% that were "C-shaped." Fifteen percent of maxillary molars had one root, 32% had two roots, 45% had three roots, and 7% had four roots. Teeth with one root demonstrated the most unusual morphology, with the number of canals varying from one to six. An in vivo study of the canal morphology of treated third molars is suggested to provide the practitioner with an understanding of the clinical implications of third molar root anatomy. PMID:11469300

Sidow, S J; West, L A; Liewehr, F R; Loushine, R J



The effect of anabolic steroids on mandibular growth.  


The aim of this study was to assess the effect of nandrolone (Deca-Durabolin, AKZO Nobel, Cambridge, United Kingdom) on mandibular growth in juvenile and adult rats with radiographic cephalometry and immunoradiology. Juvenile (n = 16) and adult (n = 16) inbred female Wistar-Kyoto rats were compared. Each group was divided into 2 subgroups with 8 experimental (E) and 8 control (C) animals in each subgroup. Lateral headfilms taken before and after the 70-day study period were analyzed. Body weight and blood serum IGF-I levels were monitored weekly. The results showed marked mandibular growth changes in both the juvenile and the adult E rats. Body weight increase was larger in the E than in the C animals. The IGF-I blood serum levels were similar in the juvenile E and C rats but higher in the adult E animals than in the adult C animals. It was found that the anabolic steroid (Deca-Durabolin) had a significant effect on mandibular growth in both juvenile and adult rats. PMID:12695771

Gebhardt, Alexander; Pancherz, Hans



Central condylar displacement with brain abscess from chronic mandibular osteomyelitis.  


In this case report, we describe a unique long-term complication from undiagnosed mandibular osteomyelitis. A 53-year-old female who underwent a dental extraction complicated by chronic postoperative odontogenic infection and cutaneous parotid fistula formation 2 years earlier presented with acute mental status change, gradual unilateral facial nerve palsy (House-Brackmann score V), and nontraumatic dislocation of the condylar head into the middle cranial fossa. The patient's chronic mandibular osteomyelitis led to glenoid fossa erosion, middle cranial fossa penetration, and temporal lobe abscess formation. A combined middle cranial fossa approach through a burr hole placed in the squamous temporal bone near the zygomatic root and intraoral mandibular approach to ipsilateral condylar head was performed to complete partial mandibulectomy, including condylectomy. The patient was treated with 6 weeks of meropenem perioperatively. Four months after the surgery, the patient had complete resolution of skull base osteomyelitis, parotid fistula, and neurologic deficits and full recovery of facial nerve function (House-Brackmann score of I). PMID:23315680

Lee, Thomas; Green, Ross; Hsu, Jack



A Correlational Study of Scoliosis and Trunk Balance in Adult Patients with Mandibular Deviation  

PubMed Central

Previous studies have confirmed that patients with mandibular deviation often have abnormal morphology of their cervical vertebrae. However, the relationship between mandibular deviation, scoliosis, and trunk balance has not been studied. Currently, mandibular deviation is usually treated as a single pathology, which leads to poor clinical efficiency. We investigated the relationship of spine coronal morphology and trunk balance in adult patients with mandibular deviation, and compared the finding to those in healthy volunteers. 35 adult patients with skeletal mandibular deviation and 10 healthy volunteers underwent anterior X-ray films of the head and posteroanterior X-ray films of the spine. Landmarks and lines were drawn and measured on these films. The axis distance method was used to measure the degree of scoliosis and the balance angle method was used to measure trunk balance. The relationship of mandibular deviation, spine coronal morphology and trunk balance was evaluated with the Pearson correlation method. The spine coronal morphology of patients with mandibular deviation demonstrated an “S” type curve, while a straight line parallel with the gravity line was found in the control group (significant difference, p<0.01). The trunk balance of patients with mandibular deviation was disturbed (imbalance angle >1°), while the control group had a normal trunk balance (imbalance angle <1°). There was a significant difference between the two groups (p<0.01). The degree of scoliosis and shoulder imbalance correlated with the degree of mandibular deviation, and presented a linear trend. The direction of mandibular deviation was the same as that of the lateral bending of thoracolumbar vertebrae, which was opposite to the direction of lateral bending of cervical vertebrae. Our study shows the degree of mandibular deviation has a high correlation with the degree of scoliosis and trunk imbalance, all the three deformities should be clinically evaluated in the management of mandibular deviation.

Yang, Yang; Wang, Na; Wang, Wenyong; Ding, Yin; Sun, Shiyao



Management of mandibular first molar with four canals in mesial root.  


Successful root canal treatment depends on adequate cleaning, shaping, and filling of the root canal system. The presence of middle mesial (MM) root canal of mandibular molars has been reported by various authors. But incidence of four canals in mesial root of mandibular molar is very rare. The aim of this case report is to present and describe the identification and management of a mandibular first molar with four canals in the mesial root and single canal in the distal root. PMID:24082581

Subbiya, Arunajatesan; Kumar, Krishnamurthy Sathish; Vivekanandhan, Paramasivam; Prakash, Venkatachalam



Three-rooted mandibular first primary molar: Report of three cases.  


Accessory root formation in primary teeth is an uncommon finding. An awareness and understanding of the presence of additional roots and unusual root canal morphology is essential as it determines the successful outcome of the endodontic treatment.This paper presents three case reports on the presence of three-rooted mandibular first primary molar (primary three-rooted mandibular left first molar and bilateral mandibular first molar). PMID:22629056

Gupta, Shilpi; Nagaveni, N B; Chandranee, N J



Three-rooted mandibular first primary molar: Report of three cases  

PubMed Central

Accessory root formation in primary teeth is an uncommon finding. An awareness and understanding of the presence of additional roots and unusual root canal morphology is essential as it determines the successful outcome of the endodontic treatment. This paper presents three case reports on the presence of three-rooted mandibular first primary molar (primary three-rooted mandibular left first molar and bilateral mandibular first molar).

Gupta, Shilpi; Nagaveni, N. B.; Chandranee, N. J.



Root and canal morphology of permanent mandibular molars in a Sri Lankan population  

Microsoft Academic Search

The main purpose of this study was to investigate the root and canal morphology of Sri Lankan mandibular molars and to determine\\u000a the affinities of these morphological variations to those of people of European and Asian origin. Two hundred mandibular first\\u000a and second molars were examined. The number of roots and the prevalence of C-shaped (gutter-shaped) roots in mandibular second

Roshan Peiris; Masami Takahashi; Kayoko Sasaki; Eisaku Kanazawa



Independent and Confluent Middle Mesial Root Canals in Mandibular First Molars: A Report of Four Cases  

PubMed Central

Mandibular molars demonstrate considerable variations with respect to number of roots and root canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. This paper discusses the endodontic management of the rare anatomical complexity middle mesial canals in mandibular first molar and also serves to remind the clinicians that such anatomical variations should be taken into account during the endodontic treatment of the mandibular molars.

Deepalakshmi, Mohanavelu; Karumaran, Chellasamy Savarimala; Miglani, Revathi; Indira, Rajamani



Management of mandibular first molar with four canals in mesial root  

PubMed Central

Successful root canal treatment depends on adequate cleaning, shaping, and filling of the root canal system. The presence of middle mesial (MM) root canal of mandibular molars has been reported by various authors. But incidence of four canals in mesial root of mandibular molar is very rare. The aim of this case report is to present and describe the identification and management of a mandibular first molar with four canals in the mesial root and single canal in the distal root.

Subbiya, Arunajatesan; Kumar, Krishnamurthy Sathish; Vivekanandhan, Paramasivam; Prakash, Venkatachalam



Mandibular midline supernumerary tooth associated with agenesis of permanent central incisors: a diagnostic conundrum.  


Concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition. The presence of this condition in the same area of dental arch and specifically in the mandibular anterior region is reported very infrequently. This case report presents a case of 20 years old male with congenitally missing permanent mandibular central incisors in conjunction with a mandibular midline supernumerary tooth. Only 3 cases have been documented in English literature till date. The article focuses on the review of mandibular mesiodens and the clarity regarding the usage of the terminology "mesiodens". PMID:23037785

Marya, Charu Mohan; Sharma, Gaurav; Parashar, Vijay P; Dahiya, Vandana; Gupta, Anil



Mandibular third molar development after mantle radiation in long-term survivors of childhood Hodgkin's disease  

SciTech Connect

Sequential panoramic radiographs were assessed for mandibular third molar development in 47 long-term survivors of childhood Hodgkin's disease after treatment with 37 Gy mantle field radiation. To make a comparison, panoramic radiographs of 149 healthy, nonirradiated children were reviewed for the presence of mandibular third molars. In children between the ages of 7 and 12 years, bilateral agenesis of mandibular third molars was more frequent in patients who had been treated with mantle radiation than in nonirradiated patients. Unilateral agenesis, crown hypoplasia, and root growth impairment of mandibular third molars were also found. Similar, apparent, radiation-induced developmental anomalies were noted in maxillary third molars of the irradiated patients.

McGinnis, J.P. Jr.; Hopkins, K.P.; Thompson, E.I.; Hustu, H.O.



In vivo behaviour of two different biphasic ceramic implanted in mandibular bone of dogs  

Microsoft Academic Search

Alloplastic calcium phosphate bone substitutes such as hydroxyapatite (HA) and tricalcium phosphate (TCP) have been studied\\u000a extensively due to their composition closely resembling the inorganic phase of bone tissue. On the same way, by manipulating\\u000a the HA\\/TCP ratio it may be possible to change the substitution rate and the bioactivity of these materials, an advantage which\\u000a has brought them to

Natalia Miño Fariña; Fernando Muñoz Guzón; Mónica López Peña; Antonio González Cantalapiedra



Mandibular reconstruction in Goldenhar syndrome using temporalis muscle osteofascial flap.  


Goldenhar syndrome is a well-known developmental anomaly of the maxillofacial skeleton and hemifacial soft tissue. Maxillofacial anomalies of that syndrome can be managed by a variety of means such as inlay- or onlay-applied nonvascularized bone grafts, vascularized osteocutaneous/osseous flaps, or distraction osteogenesis. Vascularized full-thickness calvarial bone grafting is an important option for mandibular reconstruction for cases in which, for one reason or another, other techniques are not available, not applicable, or have failed. A mandibular defect of a 6-year-old boy presenting with bilateral preauricular skin tags, right microtia, right mandibular hypoplasia (with missing right condylar head and ascending ramus of the mandible) was reconstructed with right vascularized full-thickness calvarial bone grafting. Preoperative three-dimensional computed tomographic scans were used to acquire the stereolithographic biomodeling of the patient for assessing the amount of bone defect and precise planning of the surgery. Panoramic, anteroposterior, and lateral cephalograms and three-dimensional computed tomographic scans were obtained before and after the surgery and in the follow-up period for the evaluation of amount of relapse in the follow-up period. Clinical follow up and bone scintigraphy were used to assess the viability of transferred vascularized calvarial bone graft in the postoperative period. Plain radiographic evaluation with anteroposterior radiographs showed that mandibular symmetry increased and normooclusive closure of incisive teeth was achieved after surgery and retained in the postoperative period. Radiographs taken 1 year after surgery demonstrated that there was a slight relapse (1 mm) to the right side in the mandible when the results were compared with early postoperative ones. Postoperative three-dimensional computed tomographic evaluation of bony structures 3 months after operation showed that the transferred bone retained its volume. Sequential bone scintigraphies, performed to assess the vascularity of the grafts 1 week, 1 month, and 1 year after the operation, demonstrated the viability of transferred vascularized bone graft. The temporalis muscle osteofascial flap is a reliable method for mandibular reconstruction. It lessens the operative time, lessens surgical team labor, minimizes postoperative morbidity and discomfort, minimizes the hospital stay period, and minimizes financial expenses without renouncing the bone-healing capacity and increases aesthetic outcome by camouflaging the donor site scar in scalp and minimizing the facial scarring. PMID:18216683

Canter, Halil Ibrahim; Kayikcioglu, Aycan; Saglam-Aydinatay, Banu; Kiratli, Pinar Ozgen; Benli, Kemal; Taner, Tulin; Erk, Yucel



Orthopedic Correction of Growing Hyperdivergent, Retrognathic, Patients with Miniscrew Implants  

PubMed Central

Traditional orthodontic treatments do not adequately address the skeletal problems of retrognathic, hyperdivergent, Class II adolescents; the few approaches that do require long-term patient compliance. This paper introduces a novel approach using miniscrew implants (MSIa) and growth to treat retrognathic hyperdivergent adolescents. Nine consecutive patients were evaluated at the start of treatment (13.2 ±1.1 years of age) and again at the end of the orthopedic phase (after 1.9 ±0.3 years). Each patient had two MSIs placed in either side of the palate. Coil springs (150 g) extended from the MSIs to a RPE, which served as a rigid segment for intruding the maxillary premolar and molars. Two additional MSIs were placed between the first mandibular molars and second premolars; coil spring (150 g) extended from the MSIs to hold or intrude the mandibular molars. Prior to treatment, the patients exhibited substantial and significant mandibular retrusion (Z-score=?1.0), facial convexity (Z-score=0.7), and hyperdivergence (Z-score=1.6). Treatment produced consistent and substantial orthopedic effects. The chin was advanced an average of 2.4 mm, the SNB angle increased by 2.1°, the mandibular plane angle decreased 3.9°, and facial convexity decreased by approximately 3.2°. Questionnaires showed that this treatment approach was not painful or uncomfortable; the majority of the patients indicated that they were very likely to recommend the treatment to others. Treatment was accomplished by titrating the amount of orthodontic intrusion performed based on the individuals’ growth potential.

Buschang, Peter H.; Carrillo, Roberto; Rossouw, P. Emile



Biologic stability of plasma ion-implanted miniscrews  

PubMed Central

Objective To gain basic information regarding the biologic stability of plasma ion-implanted miniscrews and their potential clinical applications. Methods Sixteen plasma ion-implanted and 16 sandblasted and acid-etched (SLA) miniscrews were bilaterally inserted in the mandibles of 4 beagles (2 miniscrews of each type per quadrant). Then, 250 - 300 gm of force from Ni-Ti coil springs was applied for 2 different periods: 12 weeks on one side and 3 weeks contralaterally. Thereafter, the animals were sacrificed and mandibular specimens including the miniscrews were collected. The insertion torque and mobility were compared between the groups. The bone-implant contact and bone volume ratio were calculated within 800 µm of the miniscrews and compared between the loading periods. The number of osteoblasts was also quantified. The measurements were expressed as percentages and analyzed by independent t-tests (p < 0.05). Results No significant differences in any of the analyzed parameters were noted between the groups. Conclusions The preliminary findings indicate that plasma ion-implanted miniscrews have similar biologic characteristics to SLA miniscrews in terms of insertion torque, mobility, bone-implant contact rate, and bone volume rate.

Cho, Young-Chae; Cha, Jung-Yul; Hwang, Chung-Ju; Park, Young-Chel; Jung, Han-Sung



Retrograde peri-implantitis  

PubMed Central

Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to) retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation.

Mohamed, Jumshad B.; Shivakumar, B.; Sudarsan, Sabitha; Arun, K. V.; Kumar, T. S. S.



Reconstruction of critical-size mandibular defects in immunoincompetent rats with human adipose-derived stromal cells.  


In patients with bony defects, autologous bone grafts are the "gold standard" for reconstruction. In children, autologous bone harvesting is limited but tissue engineering offers an alternative. Next to bone marrow, adipose tissue is a source of mesenchymal stromal cells, and adipose-derived stromal cells (ADSC) can differentiate into osteocytes. The aim of this study was to evaluate the efficacy of bioactive implants (ADSC in fibrin glue) for repair of critical-size mandibular defects in athymic rats. Human adult ADSC embedded in fibrin glue were implanted into a critical-size defect in the rat mandible and their efficacy was compared to those of protected bone healing (pbh), autologous bone graft, and an empty defect. The newly formed bone was quantified using high-resolution flat-panel volumetric CT (fpvCT) during different observation times. After eight weeks, the specimens were assessed histologically and by micro-computed tomography (?-CT). The radiographic examination demonstrated a significantly higher level of ossified defect area in the ADSC side compared with the pbh side. The autologous bone graft side showed significantly enhanced bone formation compared to the empty defect. The histological findings in the specimens with ADSC showed bony bridging of the defect. ADSC were capable of defect reconstruction under our experimental conditions. PMID:23684529

Streckbein, Philipp; Jäckel, Sven; Malik, Christoph-Yves; Obert, Martin; Kähling, Christopher; Wilbrand, Jan-Falco; Zahner, Daniel; Heidinger, Katrin; Kampschulte, Marian; Pons-Kühnemann, Jörn; Köhler, Kernt; Sauer, Heinrich; Kramer, Martin; Howaldt, Hans-Peter



Individual stereolithographic template-guided curved osteotomy for unilateral prominent mandibular angle: a case report.  


Mandibular angle osteotomy is commonly used for prominent mandibular angle contouring. Because of difficult control of the line, shape, and amount of osteotomy, many complications such as asymmetry, undercorrection, overcorrection, and formation of a second mandibular angle after surgery occurred commonly. In addition, it is more difficult to implement osteotomy exactly the same as preoperative design in curved osteotomy owing to the arc-shaped osteotomy line. Therefore, further studies are needed to explore ways to make osteotomy accurately identical with preoperative design. In this report, a case of curved osteotomy guided by a stereolithographic template for unilateral prominent mandibular angle is described. We established the osteotomy line, the shape, and the volume with Mimics software for the right prominent mandibular angle; fabricated individual osteotomy template with computer-aided design/computer-aided manufacturing (CAD/CAM) technique; and performed curved osteotomy with the template. A secure fit of the template on the bone surface was found during the operation. Computed tomographic scan after the surgery revealed that bilateral mandibular angles were symmetric, that the right mandibular angle had a natural curve, and that the osteotomy line, shape, and amount were in accordance with the preoperative design. It is suggested that CAD/CAM template could guide curved osteotomy for prominent mandibular angle accurately, improve efficiency, and avoid complications in osteotomy. PMID:23714995

Rong, Qiong; Zhu, Shuangxi; Chen, Songling; Zhang, Xing



Mandibular rest position: A reliable position influenced by head support and body posture  

Microsoft Academic Search

This prospective study was designed to establish how the positions of the molars and the condyles are related to incisor position in the mandibular rest position and how their positions are altered by changing head posture. Measurements of the mandibular rest position were taken on 24 men (age range, 23 to 35) with normal Class I occlusion, skeletal patterns, and

E. MacKay Tingey; Peter H. Buschang; Gaylord S. Throckmorton



Control of mandibular incisors with the combined Herbst and completely customized lingual appliance - a pilot study  

Microsoft Academic Search

BACKGROUND: The traditional Herbst appliance induces mandibular incisor proclination independent of the anchorage system used. The dental effects of the Herbst appliance as an element of a completely customized lingual orthodontic (LO) appliance (Incognito, 3 M) has not been analyzed yet and the aim of this paper was to measure the effect of mandibular incisor proclination using this Herbst-LO device.

Dirk Wiechmann; Rainer Schwestka-Polly; Hans Pancherz; Ariane Hohoff



Masticator Space Abnormalities Associated with Mandibular Osteoradionecrosis: MR and CT Findings in Five Patients  

Microsoft Academic Search

BACKGROUND AND PURPOSE:Imaging of patients with a clinical diagnosis of mandibular osteoradionecrosis (ORN) is often performed to support that clinical suspicion, evaluate the extent of the disease, or exclude coexistent tumor recurrence. The purpose of our study was to describe the clinical, MR imaging, and CT features of five patients with mandibular ORN associated with prominent soft-tissue abnormality in the

June Chong; Lisa K. Hinckley; Lawrence E. Ginsberg


Clinical observations of the anatomy and function of the marginal mandibular nerve  

Microsoft Academic Search

The objective of this study was to assess the anatomical variation of the marginal mandibular nerve, and evaluate the risk of nerve malfunction after neck dissection. The method involved clinical assessment of the anatomy and function of the marginal mandibular nerve in 133 neck dissections. When the neck was extended the nerve was displaced in an anterior and downward direction

R. W. Nason; A. Binahmed; M. G. Torchia; J. Thliversis



Developmental origins and evolution of jaws: new interpretation of “maxillary” and “mandibular  

Microsoft Academic Search

Cartilage of the vertebrate jaw is derived from cranial neural crest cells that migrate to the first pharyngeal arch and form a dorsal “maxillary” and a ventral “mandibular” condensation. It has been assumed that the former gives rise to palatoquadrate and the latter to Meckel's (mandibular) cartilage. In anamniotes, these condensations were thought to form the framework for the bones

Robert Cerny; Peter Lwigale; Rolf Ericsson; Daniel Meulemans; Hans-Henning Epperlein; Marianne Bronner-Fraser



Repair of canine mandibular bone defects with bone marrow stromal cells and porous ?-tricalcium phosphate  

Microsoft Academic Search

Tissue engineering has become a new approach for repairing bone defects. Previous studies have been limited to the use of slow-degradable scaffolds with bone marrow stromal cells (BMSCs) in mandibular reconstruction. In this study, a 30mm long mandibular segmental defect was repaired by engineered bone graft using osteogenically induced autologouse BMSCs seeded on porous ?-tricalcium phosphate (?-TCP, n=5). The repair

Jie Yuan; Lei Cui; Wen Jie Zhang; Wei Liu; Yilin Cao



Trends in the incidence and cause of sport-related mandibular fractures: A retrospective analysis  

Microsoft Academic Search

Purpose: This study assessed changes in the incidence and causes of mandibular fractures occurring in Innsbruck, Austria between 1984 and 1993.Patients and Methods: Records from 712 patients sustaining 982 mandibular fractures were reviewed and analyzed according to age, sex, date of fracture, place of trauma, cause, anatomic site of fracture, and associated orofacial and craniocerebral injuries.Results: Sports were the most

Rüdiger Emshoff; Harald Schöning; Gabriel Röthler; Ernst Waldhart



No Correlation between Primary Mandibular Anterior Crowding and Vertical Craniofacial Configuration or Lower Incisor Inclination  

Microsoft Academic Search

The aim of the present study was to evaluate the correlation between primary mandibular anterior crowding and vertical cranofacial configuration or sagittal lower incisor inclination. The collective comprised 100 consecutive patients (50 males, 50 females) subject to 4 selection criteria: mandibular anterior crowding S 1.0 mm, no provious orthodontic therapy, completely preserved deciduous canines and molars, and lateral cephalograms of

Rainer-Reginald Miethke



Repair of experimental mandibular defects in rats with autogenous, demineralised, frozen and fresh bone  

Microsoft Academic Search

This prospective experimental study aimed to assess the regenerative capability of demineralised bone autografts resected and replaced orthotopically, compared with traditional fresh and deep frozen mandibular autografts in rats. In 60 adult Wistar rats, a bone defect 4 × 4 mm was created at the left ascending mandibular ramus and the removed bone was used as a fresh (n=20), deep

L. M. Redondo; A. Verrier Hernández; J. M. Garcia Cantera; M. A. Torres Nieto; C. Vaquero Puerta




Microsoft Academic Search

Differences in the ultrastructure and function of the mandibular glands in developing workers and mature males of the meliponine stingless bee Scaptotrigona postica suggest that there are age-dependent variations in the contents of the secretion and glandular functions. In this work, we used transmission (TEM) and scanning (SEM) electron microscopy to examine the mandibular glands of S. postica workers of

Luciana Fioretti Gracioli-Vitti; Fábio Camargo Abdalla


Asymmetric muscle function in patients with developmental mandibular asymmetry.  


The aim was to test the hypothesis that developmental mandibular asymmetry is associated with increased asymmetry in muscle activity. Patients with mandibular condylar and/or ramus hyperplasia having unilateral cross-bite were compared with healthy subjects with normal occlusion. Muscle activity was recorded with surface electrodes in the masseter, suprahyoid, sternocleidomastoid muscle (SCM) and upper trapezius areas during jaw opening-closing-clenching, head-neck flexion-extension, and elevation-lowering of shoulders. Root mean square (RMS) and mean power frequency (MPF) values were calculated and analysed using anova and t-tests with P < 0.05 chosen as significance level. The SCM and masseter muscles showed co-activation during jaw and head movements, significantly more asymmetric in the patients than in the healthy subjects. The RMS and MPF values were higher in the patients than in the controls in the SCM and suprahyoid areas on both sides during jaw opening-closing movement. The results indicate that the ability to perform symmetric jaw and neck muscle activities is disturbed in patients with developmental mandibular asymmetry. This is of clinical interest because asymmetric activity may be an etiologic factor in temporomandibular joint and cervical pain. The results support that co-activation occurs between jaw and neck muscles during voluntary jaw opening and indicate that postural antigravity reflex activity occurs in the masseter area during head extension. Further studies, where EMG recordings are made from the DMA patients at early stages are motivated to verify activity sources and test if the asymmetric activity is associated with muscle and joint pain in the jaw and cervical areas. PMID:18190358

Dong, Y; Wang, X M; Wang, M Q; Widmalm, S E



Intraoral One-Stage Curved Osteotomy for the Prominent Mandibular Angle: A Clinical Study of 407 Cases  

Microsoft Academic Search

Background: Many Oriental people have a square face with a prominent mandibular angle. This article presents a good osteotomy method for the prominent mandibular angle (PMA). Methods: Two modifications of the conventional procedures have been made. The first is a one-stage curved osteotomy for the mandibular angle. The second is nonresection of the masseter muscle. The surgical procedure has been

Lai Gui; Dong Yu; Zhiyong Zhang; L. V. Changsheng; Xiaojun Tang; Zhongmei Zheng



Vascularized mandibular anterior ameloblastoma - an entity still unresolved.  


Vascularized ameloblastoma is a bewildering entity whose existence is questionable from its origin to nosology and its very characterization as a distinct variant of ameloblastoma. This uncertainty is largely because of a fewer number of documented cases and loss of long-term follow-up. The current paper describes two cases of ameloblastoma in the mandibular anterior region, which had features of so-called "hemangiomatous ameloblastoma" as it was originally described. Understanding its pathophysiology based on various views and clinical implications in terms of its biologic behavior are brought to light in this paper. PMID:23715203

Maheshwari, P; Chandrashekhar, C; Radhakrishnan, R



Aneurysmal bone cyst, a lesion of the mandibular condyle.  


Benign and malignant tumors of the temporomandibular joint are rare. An aneurysmal bone cyst (ABC) of the condyle is even more unusual and usually presents as a slowly enlarging firm swelling which occasionally may be associated with pain and tenderness. Surgical curettage or excision is the treatment of choice, in an attempt to reduce the potential problem of recurrence; we undertook surgical resection of the affected bone. Immediate mandibular reconstruction using autologous bone was deferred though it is generally recommended in such type of cases. PMID:23730077

Rai, Kirthi Kumar; Rana Dharmendrasinh N; Shiva Kumar, H R



Bilateral bifid mandibular condyles diagnosed with three-dimensional reconstruction.  


Bifid mandibular condyles (BMCs) are rare anomalies. The overwhelming majority of prior reports described their predominantly unilateral occurrence diagnosed by panoramic radiography. We present an even rarer case of bilateral BMC initially identified by panoramic radiography and confirmed with colour-enhanced three-dimensional CT. These images substantiate the theory that the secondary condyles arise from the neck of the mandible (Lopez-Lopez et al. Bifid condyle: review of the literature of the last 10 years and report of two cases. Cianio 2010; 28: 136-140). PMID:22241877

Tanner, J M; Friedlander, A H; Chang, T I



Unilateral single-rooted primary mandibular first molar.  


A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna



Mandibular reconstruction using an axially vascularized tissue-engineered construct  

PubMed Central

Background Current reconstructive techniques for continuity defects of the mandible include the use of free flaps, bone grafts, and alloplastic materials. New methods of regenerative medicine designed to restore tissues depend mainly on the so-called extrinsic neovascularization, where the neovascular bed originates from the periphery of the construct. This method is not applicable for large defects in irradiated fields. Methods We are introducing a new animal model for mandibular reconstruction using intrinsic axial vascularization by the Arterio-Venous (AV) loop. In order to test this model, we made cadaveric, mechanical loading, and surgical pilot studies on adult male goats. The cadaveric study aimed at defining the best vascular axis to be used in creating the AV loop in the mandibular region. Mechanical loading studies (3 points bending test) were done to ensure that the mechanical properties of the mandible were significantly affected by the designed defect, and to put a base line for further mechanical testing after bone regeneration. A pilot surgical study was done to ensure smooth operative and post operative procedures. Results The best vascular axis to reconstruct defects in the posterior half of the mandible is the facial artery (average length 32.5 ± 1.9 mm, caliber 2.5 mm), and facial vein (average length 33.3 ± 1.8 mm, caliber 2.6 mm). Defects in the anterior half require an additional venous graft. The defect was shown to be significantly affecting the mechanical properties of the mandible (P value 0.0204). The animal was able to feed on soft diet from the 3rd postoperative day and returned to normal diet within a week. The mandible did not break during the period of follow up (2 months). Conclusions Our model introduces the concept of axial vascularization of mandibular constructs. This model can be used to assess bone regeneration for large bony defects in irradiated fields. This is the first study to introduce the concept of axial vascularization using the AV loop for angiogenesis in the mandibular region. Moreover, this is the first study aiming at axial vascularization of synthetic tissue engineering constructs at the site of the defect without any need for tissue transfer (in contrast to what was done previously in prefabricated flaps).



Mandibular distraction in a neonate with muscular dystrophy.  


The following case report describes the successful use of distraction osteogenesis (DO) for the treatment of hypoplasia of the mandible in a patient with muscular dystrophy (MD). While DO has been used for hypoplasia of the mandible, no evidence exists that is it safe in the setting of MD. MD is a disease that primarily affects skeletal muscle; however, pathologic changes in the adjacent bone have been described. Furthermore, the healing of involved bone may be problematic, making DO a potentially unsuccessful technique in this group of patients. This report is the first successful utilization of DO for the treatment of mandibular hypoplasia in a patient with MD. PMID:16258306

Taub, Peter J; Koch, R Michael; Merer, David; Geldzahler, Gerald; Geldzhaler, Gerald



3D reconstruction of two C-shape mandibular molars.  


Two mandibular second molars, with an indication of C-shape morphology were processed for 3-D reconstruction. After serial cross sectioning, photographs of the sections were digitized and by using surface representation, 3D reconstruction was achieved. The first molar as the 3D reconstruction showed was single rooted with one C-shaped root canal with two foramens, while the second one was double rooted with two root canals, one C-shaped and one thin, having a common foramen. PMID:9220739

Lyroudia, K; Samakovitis, G; Pitas, I; Lambrianidis, T; Molyvdas, I; Mikrogeorgis, G



Mandibular ameloblastoma in an elderly patient: a case report.  


Ameloblastomas frequently occur in relatively young people, but are rarely seen in people aged 80 years or older. We report a case of mandibular ameloblastoma in an elderly patient with a review of the literature. The patient was a 82-year-old man who noticed swelling of the gingiva approximately 2 weeks prior to his initial visit. Computed tomography showed a radiolucent area with little radiopacity. Internal uniformity was observed at the site, with thinning of cortical bone which lacked continuity in some areas. The excision and curettage were performed under general anaesthesia. No recurrence has been observed 14 months after surgery. PMID:23533821

Nagata, Kokoro; Shimizu, Kasumi; Sato, Chu; Morita, Hiroshi; Watanabe, Yoshihiro; Tagawa, Toshiro



Mandibular Ameloblastoma in an Elderly Patient: A Case Report  

PubMed Central

Ameloblastomas frequently occur in relatively young people, but are rarely seen in people aged 80 years or older. We report a case of mandibular ameloblastoma in an elderly patient with a review of the literature. The patient was a 82-year-old man who noticed swelling of the gingiva approximately 2 weeks prior to his initial visit. Computed tomography showed a radiolucent area with little radiopacity. Internal uniformity was observed at the site, with thinning of cortical bone which lacked continuity in some areas. The excision and curettage were performed under general anaesthesia. No recurrence has been observed 14 months after surgery.

Nagata, Kokoro; Shimizu, Kasumi; Sato, Chu; Morita, Hiroshi; Watanabe, Yoshihiro; Tagawa, Toshiro



Morphometrical analysis of the human mandibular canal: a CT investigation  

Microsoft Academic Search

Purpose  This study aimed to clarify the correct localization of the mandibular canal (MC) that is essential in order to avoid injuries\\u000a to the inferior alveolar neurovascular bundle during oral surgical procedures.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We have analyzed the position of the MC using computed tomography data bank examinations of the oral region from 50 partially\\u000a dentulous Brazilian patients aging from 25 to 75 years

Marcello Rodrigues de Oliveira Júnior; André Luis Santos Saud; Debora Rodrigues Fonseca; Bernardo De-Ary-Pires; Mário Ary Pires-Neto; Ricardo de Ary-Pires



A retrospective study of mandibular fracture in a 40-month period.  


This retrospective study evaluated the epidemiology, treatment and complications of mandibular fracture associated, or not associated, with other facial fractures, when the influence of the surgeon's skill and preference for any rigid internal fixation (RIF) system devices was minimized. The files of 700 patients with facial trauma were available, and 126 files were chosen for review. Data were collected regarding gender, age, race, date of trauma, date of surgery, addictions, etiology, signs and symptoms, fracture area, complications, treatment performed, date of hospital discharge, and medication. 126 patients suffered mandibular fractures associated, or not, with other maxillofacial fractures, and a total of 201 mandibular fractures were found. The incidence of mandibular fractures was more prevalent in males, in Caucasians and during the third decade of life. The most common site was the condyle, followed by the mandibular body. The therapy applied was effective in handling this type of fracture and the success rates were comparable with other published data. PMID:19914802

de Matos, F P; Arnez, M F M; Sverzut, C E; Trivellato, A E



A protocol for maxillary reconstruction following oncology resection using zygomatic implants.  


The purpose of this clinical report is to present a surgical and prosthodontic reconstructive protocol for 20 patients who underwent maxillary resection following malignancy to the head and neck region. This protocol was developed over a period of 7 years while treating a series of 20 maxillary resections due to oncology. Patients were reconstructed prosthodontically using fixed-removable overdentures or fixed prostheses, with and without separate obturators. The treatment protocol includes a comprehensive diagnostic phase, resection surgery with immediate implant placement and temporary obturation, post resection evaluation, and prosthodontic rehabilitation. Treatment periods ranged from 6 to 96 months and success was evaluated using strict clinical, radiologic, esthetic, and functional criteria. Postsurgical radiology was undertaken at 6 monthly intervals. Almost all maxillary defects resulting from anatomic disruption of the maxillofacial complex can be well rehabilitated functionally and esthetically using this protocol in conjunction with standard implantology and fixed/fixed-removable prosthodontic principles. This protocol simplifies the rehabilitation and management of these defects by reducing surgical intervention, hosptilization, postoperative morbidity and treatment time, and prosthodontic procedural complications. PMID:17944344

Boyes-Varley, John G; Howes, Dale G; Davidge-Pitts, Keith D; Brånemark, Ingvar; McAlpine, John A


Floor of mouth haemorrhage and life-threatening airway obstruction during immediate implant placement in the anterior mandible.  


A majority of the procedures performed in the dental office setting are considered safe and minimally invasive. Despite this fact, as healthcare providers it is our responsibility to be able to anticipate, recognize and manage life-threatening emergencies that may occur. In the following report, the authors will describe a life-threatening complication that resulted from the placement of mandibular implants. PMID:16829038

Woo, B M; Al-Bustani, S; Ueeck, B A



[Treatment planning in patients with a severe reduced dentition].  


Because loss of teeth many people have a reduced maxillary and mandibular dentition. The appropriate prosthetic rehabilitation is dependent on whether or not a standard mutilation of the dentition can be achieved. In this article, the focus is on treatment of a remaining mandibular dentition combined with an edentulous maxilla, whether or not with a reduced residual alveolar ridge. In the literature, there is no consensus on the appropriate prosthetic treatment if implant-supported overdentures are not applicable. The amount of bone loss in already during some time edentulous maxillary and mandibular alveolar ridge segments as well as the available vertical space for the removable (partial) denture are important decision-making factors. PMID:19999670

Kalk, W; Schwencke, B M; Droulias, N; ten Dam, K M A



Tuberculous osteomyelitis of mandibular condyle: a diagnostic dilemma  

PubMed Central

The incidence of tuberculosis (TB) is increasing worldwide and so are its consequences. Its oral manifestations are infrequent, occurring in approximately 3% of all cases. Although the primary lesion occurs as a pulmonary infection, the extrapulmonary infections have also shown an increase over the past few years. These infections generally involve the head and neck through haematogenous or lymphatic routes. The clinical presentation may be as an ulcer, granuloma, orofacial TB, TB of the salivary glands or tuberculous lymphadenitis. Rarely, secondary oral manifestations associated with pulmonary infection are seen, which can appear as lesions on the gingiva, palate, lips, tongue, buccal mucosa, frenulum and in the jaw bones. Owing to the rarity of orofacial TB, it seldom arouses clinical suspicion, especially when a positive history of a systemic infection or therapy is denied. Tuberculous involvement of the mandibular condyle is even rarer, and only two such cases are reported so far, both in English-language literature. Further, the diagnosis of such a case is extremely difficult as there are no specific signs pathogonomic of infection. The only manifestation may be a localized painful swelling of the jaw. The presented case is of osteomyelitis of the mandibular condyle in a 20-year-old male patient in whom TB was later suspected. In this case report the role of diagnostic techniques is emphasized as the osteomyelitis of the condyle has the risk of being easily missed owing to its atypical signs and symptoms and atypical radiographic appearance.

Sheikh, S; Pallagatti, S; Gupta, D; Mittal, A



Incidence of mandibular fractures in Eastern part of Libya.  


The objective of this retrospective study is to evaluate the incidence of mandibular fractures in the eastern part of Libya and to present our experience in treating this type of facial fracture. We analyzed factors such as the incidence of age, sex, time distribution, cause and site of the fracture and the associated injuries in 493 patients presenting a total of 666 mandibular fractures. These patients were treated at Al-Jala Trauma Hospital, Benghazi-Libya between 2000 and 2006. The results were obtained from 432 males and 61 females, for which the ages ranged from 8 months to 72 years. The maximum number of the patients was recorded in 2004, and the busiest month was May. The most common cause of fracture was road traffic accidents and the most common site was the parasymphysis. Among those treated with closed reduction were 241 patients, whereas 201 patients were treated with open reduction. In conclusion, we found that the results were similar to most studies from developing countries and were in contrast to other studies. This may be due factors such as geography, socioeconomic trends, religion, road traffic legislation and seasons, which differ from one country to another. The period during which there was an embargo in Libya also appears to have affected the results. PMID:19680213

Elgehani, Rafa-Abdelsalam; Orafi, Maraai-Idris



Variable permanent mandibular first molar: Review of literature  

PubMed Central

Introduction: The success of root canal therapy depends on the locations of all the canals, thourough debridement and proper sealing. At times the clinicians are challenged with variations in morphology of root canal. This review article attempts to list out all the variations of permanent mandibular first molar published so for in the literature. Materials and Methods: An exhaustive search was undertaken using PUBMED database to identify published literature from 1900 to 2010 relating to the root canal morphology of permanent first molar by using key words. The selected artcles were obtained and reviewed. Results: Total ninty seven articles were selected out of which 50 were original article and forty seven were case reports. The incidence of third canal in mesial root was 0.95% to 15%. The incidence of three rooted mandibular first molar was 3% to 33%. Only ninety cases reported with c-shape canal configuration. Incidence of Taurodintism without congenital disorder was very rare. Conclusion: The root canal treatment requires proper knowlegde of variations in root canal morphology in order to recognise, disinfect and seal all portal of exit. This can be accomplished with proper diagnosis using newer modes, modification in access preparation, use of operating microscope, enhanced methods of disinfecting and sealing of all canals.

Ballullaya, Srinidhi V; Vemuri, Sayesh; Kumar, Pabbati Ravi



Mandibular ramus: An indicator for sex determination - A digital radiographic study  

PubMed Central

Background: The identification of skeletal remains is of paramount importance in medico-legal investigations. The skeletal components most often investigated for gender determination are the pelvis and skull, with the mandible being a practical element to analyze sexual dimorphism in the fragmented bones. Presence of a dense layer of compact bone makes it very durable and well preserved than many other bones. Mandibular ramus can be used to differentiate between sexes and it also expresses strong univariate sexual dimorphism. When skeleton sex determination is considered, metric analyses on the radiographs are often found to be of superior value owing to their objectivity, accuracy, and reproducibility. Aims and Objectives: (1) To measure, compare, and evaluate the various measurements of mandibular ramus as observed on orthopantomographs. (2) To assess the usefulness of mandibular ramus as an aid in sex determination. Materials and Methods: A retrospective study was conducted using orthopantomographs of 50 males and 50 females, which were taken using Kodak 8000C Digital Panoramic and Cephalometric System (73 kVp, 12 mA, 13.9 s). Mandibular ramus measurements were carried out using Master View 3.0 software. The measurements of the mandibular ramus were subjected to discriminant function analysis. Results: We observed each variable of the mandibular ramus to be a significant predictor in classifying a given sample (P < 0.001). Conclusion: This study on mandibular ramus measurements using orthopantomograph shows strong evidence suggesting that the ramus can be used for gender determination for forensic analysis.

Indira, Annamalai Ponnuswamy; Markande, Archana; David, Maria P



The role of TGF-? signaling in regulating chondrogenesis and osteogenesis during mandibular development  

PubMed Central

During craniofacial development, Meckel’s cartilage and the mandible bone derive from the first branchial arch, and their development depends upon the contribution of cranial neural crest (CNC) cells. We previously demonstrated that conditional inactivation of Tgfbr2 in the neural crest of mice (Tgfbr2fl/fl;Wnt1-Cre) results in severe defects in mandibular development, although the specific cellular and molecular mechanisms by which TGF-? signaling regulates the fate of CNC cells during mandibular development remain unknown. We show here that loss of Tgfbr2 does not affect the migration of CNC cells during mandibular development. TGF-? signaling is specifically required for cell proliferation in Meckel’s cartilage and the mandibular anlagen and for the formation of the coronoid, condyle and angular processes. TGF-?-mediated connective tissue growth factor (CTGF) signaling is critical for CNC cell proliferation. Exogenous CTGF rescues the cell proliferation defect in Meckel’s cartilage of Tgfbr2fl/fl;Wnt1-Cre mutants, demonstrating the biological significance of this signaling cascade in chondrogenesis during mandibular development. Furthermore, TGF-? signaling controls Msx1 expression to regulate mandibular osteogenesis as Msx1 expression is significantly reduced in Tgfbr2fl/fl;Wnt1-Cre mutants. Collectively, our data suggest that there are differential signal cascades in response to TGF–? to control chondrogenesis and osteogenesis during mandibular development.

Oka, Kyoko; Oka, Shoji; Sasaki, Tomoyo; Ito, Yoshihiro; Bringas, Pablo; Nonaka, Kazuaki; Chai, Yang



Pacemakers and Implantable Defibrillators  


... arrhythmia is serious, you may need a cardiac pacemaker or an implantable cardioverter defibrillator (ICD). They are ... are implanted in your chest or abdomen. A pacemaker helps control abnormal heart rhythms. It uses electrical ...


Dental Implant Surgery  


Dental implant surgery Basics Multimedia Expert Answers Resources Reprints A single copy of this article may be reprinted for personal, noncommercial use only. Dental implant surgery By Mayo Clinic staff Original Article: http:// ...


Implantable CMOS Biomedical Devices  

PubMed Central

The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented.

Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko



Radial-capitellar implant  

US Patent & Trademark Office Database

A radial-capitellar implant for surgical replacement of the capitellum of the humerus and, optionally, the head of the radius. The radial-capitellar implant includes a capitellar implant or surface replacement arthroplasty of the capitellum and a radial prosthesis for replacement of the head of the radius. In one embodiment the radial prosthesis includes an articular head which moveable articulates with a stem implantable in the radius.

Cooney, III; William P. (Rochester, MN); Morrey; Bernard F. (Rochester, MN); Leibel; David A. (Princeton, MN)



A no bleed implant  

Microsoft Academic Search

Breast implants have evolved from the original saline-filled, smooth-surfaced silicone rubber bag to silicone gel-filled smooth-walled sacs to a combination of a silicone gel-filled bag within a saline-filled sac, and, most recently, a reversed, double-lumen implant with a saline bag inside of a gel-filled bag. Texture-surfaced implants were first used in 1970 when the standard silicone gelfilled implant was covered

Robert A. Ersek; Jose Alberto Navarro; Dora Zsofia Nemeth; George Sas



Ion implantation in China  

Microsoft Academic Search

Ion implantation in silicon has been widely used in the production of semiconductor devices and integrated circuits in China. Research of low energy ion implantation, high energy ion implantation and the SOI technology is in progress. Fully Si-implanted planar GaAs dual-gate MESFETs, high linear GaAs Hall effect sensors, light emitting diodes, laser devices, and infrared detectors made of HgCdTe have

Zou Shichang; Liu Xianghuai



Immediate Occlusal Loading of NanoTite™ Tapered Implants: A Prospective 1-Year Clinical and Radiographic Study.  


Background: During the last decade, high success rates have been reported for implants placed with immediate loading procedures, especially when bone quality and quantity provide good implant stability. In many of these studies, straight-walled implants with moderately rough surfaces were employed. Tapered implants are becoming increasingly more popular due to standardized drilling protocols and reports of high initial primary stability. Purpose: The aim of the present prospective, single center clinical study was to evaluate surface topographical analysis and the clinical and radiographic outcomes of the NanoTite™ (BIOMET 3i, Palm Beach Gardens, FL, USA) Tapered Implant when used for immediate loading of fixed prostheses and single-tooth restorations. Materials and Methods: Forty-two patients who needed implant treatment and met admission criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 30?Ncm prior to final seating and an implant stability quotient above 55. A total of 139 NanoTite Tapered implants (112 maxillary and 27 mandibular) were placed by one investigator, and the majority of these implants (n?=?77/55%) were placed in posterior regions, and in soft bone (n?=?90/65%). A total of 57 prosthetic constructions were evaluated consisting of 20 single-tooth restorations, 30 fixed partial dentures, and 7 complete, fixed maxillary restorations. Radiographs were taken at baseline and at 12 months of follow-up. Results: Of the 139 study implants, one implant failure was declared. The overall cumulative survival rate at 1 year is 99.4%. Mean marginal bone resorption is 1.01?mm (SD 0.85) during the first year of function. Conclusion: Although limited to the short follow-up, immediate loading of NanoTite Tapered implants seems to be a viable option in implant rehabilitation, when insertion torque of at least 30?Ncm is achieved. Further studies are needed to authenticate the finding of this study. PMID:22251669

Ostman, Pär-Olov; Wennerberg, Ann; Ekestubbe, Annika; Albrektsson, Tomas



Anesthetic efficacy of infiltrations in mandibular anterior teeth.  

PubMed Central

The purpose of this prospective, randomized, double-blind study was to measure the degree of anesthesia obtained with a labial infiltration of either 2% lidocaine with 1:50,000 or 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Another objective was to measure the degree of anesthesia obtained with a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Through use of a repeated-measures design, 40 subjects randomly received a labial infiltration at the lateral incisor apex of either 1.8 mL of 2% lidocaine with 1:100,000 epinephrine or 1.8 mL of 2% lidocaine with 1:50,000 epinephrine at 2 separate appointments. An additional 40 subjects received a lingual infiltration at the lateral incisor apex of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. The mandibular anterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. For the 3 infiltrations, success rates for the lateral incisor ranged from 43 to 50%. Adjacent teeth had success rates of 27 to 63%. There was no significant difference (P > 0.05) in success between the labial infiltration of 2% lidocaine with 1:100,000 epinephrine and 2% lidocaine with 1:50,000 epinephrine or the lingual infiltration of 2% lidocaine with 1:100,000 epinephrine when compared with the labial infiltration of 2% lidocaine with 1:100,000 epinephrine. Duration of pulpal anesthesia declined steadily for all solutions over the 60 minutes. In conclusion, the success rate of 43-50% and declining duration of pulpal anesthesia over an hour indicates that a labial infiltration of 1.8 mL of either 2% lidocaine with 1:100,000 epinephrine or 1: 50,000 epinephrine or a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine over the lateral incisor apex cannot be recommended clinically to provide profound pulpal anesthesia.

Yonchak, T.; Reader, A.; Beck, M.; Clark, K.; Meyers, W. J.



Free Microsurgical and Pedicled Flaps for Oncological Mandibular Reconstruction: Technical Aspects and Evaluation of Patient Comorbidities  

PubMed Central

Oncologic mandibular reconstruction has changed significantly over the years and continues to evolve with the introduction of newer technologies and techniques. Patient demographic, reconstructive, and complication data were obtained from a prospectively maintained clinical database of patients who underwent head and neck reconstruction at our institution. The free fibular flap is now considered the gold standard for mandibular reconstruction. However, in patients with multiple comorbidities, lengthy procedures may be less optimal and pedicled flaps, with specific modifications, can yield reasonable outcomes. Technical aspects and comorbidity profiles are examined in the oncological mandibular reconstruction cohort.

Hassid, Victor J.; Maqusi, Suhair; Culligan, Emmett; Cohen, Mimis N.; Antony, Anuja K.



Transmigration of Mandibular Canine: Report of Four Cases and Review of Literature  

PubMed Central

Transmigration of canine is a rare phenomenon. The prevalence of transmigration of mandibular canine has been found to be only 0.14%–0.31%. The treatment of impacted transmigrated canine is very complicated if it is diagnosed at a later stage. We report 4 cases of transmigration of mandibular canine and review the literature regarding the etiology and treatment. Panoramic radiograph should be taken during the mixed dentition period if the mandibular canine has not erupted from more than one year from its normal chronological age of eruption as intraoral periapical radiograph examination will not always detect an impacted or transmigrated canine.

Sharma, Gaurav; Nagpal, Archna



Reconstruction of a bilateral mandibular defect due to trauma using a single fibula free flap.  


The reconstruction of noncontiguous bilateral mandibular defects using a single bony free flap is rarely performed because such defects are seldom encountered. This report describes the reconstruction of a bilateral body defect caused by shrapnel injury. A free vascularized osteomyocutaneous fibula flap was designed to replace 2 mandibular defects in the patient. The midportion of the fibula was resected without damage to the periosteum and vascular pedicle, and a skin paddle was used to monitor the flap. This would appear to be the first report of its use in the reconstruction of bilateral mandibular defects from trauma. PMID:23911144

Ekanayake, Kumara; G Thomas, Deepak; A Brennan, Peter



A New Anatomically Based Nomenclature for the Roots and Root Canals--Part 2: Mandibular Molars  

PubMed Central

Several terminologies have been employed in the dental literature to describe the roots and root canal systems of mandibular molars with no consensus being arrived at, thus far. The anatomical relation of roots and their root canals were identified and a naming system was formulated. The proposed nomenclature attempts to make certain essential modifications to the traditional approach to accommodate the naming of various aberrations presented in mandibular molars. A simple, yet extensive nomenclature system has been proposed that appropriately names the internal and external morphology of mandibular molars.

Valerian Albuquerque, Denzil; Kottoor, Jojo; Velmurugan, Natanasabapathy



Permanent mandibular incisor with multiple anomalies - report of a rare clinical case.  


Permanent mandibular central incisor is rarely affected by tooth shape anomalies of crown and root. Co-occurrence of multiple anomalies in a permanent mandibular central incisor is extremely rare. This paper reports an unusual concurrent combination of multiple dental anomalies affecting both the crown and root of a permanent mandibular left central incisor - talon cusp, dens invaginatus, short root anomaly and macrodontia -, which has not previously been reported together. Case management is described and implications are discussed. The dentist should be aware of these rare entities in order to provide an accurate diagnosis and management for which detailed examination of the tooth both clinically and radiographically is very important. PMID:21861037

Nagaveni, Nayaka Basavanthappa; Umashanikara, Kagathur Veerbadrapa; Vidyullatha, B G; Sreedevi, Sreedevi; Radhika, Nayaka Basavanthappa



Mandibular distraction osteogenesis by sagittal split osteotomy and intraoral curvilinear distraction.  


Mandibular distraction combining the sagittal split ramus osteotomy and an intraoral curved distractor is efficacious to lengthen the mandibular body and ramus. The sagittal split permits immediate rotation of the proximal segment and lengthening while still providing a large surface interface for regenerative bone. The buried curved distractor enables mandibular lengthening along the normal logarithmic grow spiral as shown by Moss and Rickets. In addition, it is well tolerated by the patient and can remain in place for a long duration to provide support. In summary, this combination of surgical techniques provides certain advantages for distraction of the mandible. PMID:15213543

Schendel, Stephen A; Linck, Donald W



Hydrogen implanted silicon oxidation  

Microsoft Academic Search

The oxidation rate and the oxide thickness of the hydrogen ion implanted silicon wafers were examined. It was observed that the native oxide thickness is higher for the H+ implanted Si(100) compared to the Si(111). Also the native oxide thickness depended on the implanted hydrogen distribution. The thickness increased with the hydrogen con-centration. The oxide thickness after wet oxidization of

S. Hava; B. M. Lacquet; P. L. Swart



Effects of anodized implants coated with Escherichia coli-derived rhBMP-2 in beagle dogs.  


This study evaluated the effects of Escherichia coli-derived rhBMP-2 (ErhBMP-2) coated onto anodized implants to stimulate bone formation, osseointegration and vertical bone growth in a vertical bone defect model. Six young adult beagle dogs were used. After a 2-month bone healing period, anodized titanium implants (8mm in length) were placed 5.5mm into the mandibular alveolar ridge. Eighteen implants coated with ErhBMP-2 (BMP group) and another 18 uncoated implants (control group) were installed using a randomized split-mouth design. The implant stability quotient (ISQ) values were measured. Specimens were fabricated for histometric analysis to evaluate osseointegration and bone formation. The ISQ values at 8 weeks after implant placement were significantly higher in the BMP group than in the control group (p<0.05). Histological observations showed that the changes in bucco-lingual alveolar bone levels were higher in the BMP group than in the control group (p<0.05). The ErhBMP-2 coated anodized implants can stimulate bone formation and increase implant stability significantly on completely healed alveolar ridges in dogs. Further studies evaluating the effects of ErhBMP-2 on osseointegration in the bone-implant interface are warranted. PMID:22575178

Huh, Jung-Bo; Kim, Sung-Eun; Kim, Hyo-Eon; Kang, Seong-Soo; Choi, Kyung-Hee; Jeong, Chang-Mo; Lee, Jeong-Yol; Shin, Sang-Wan



Finite element stress analysis of cuneiform and cylindrical threaded implant geometries.  


Statement of problem. Different implant geometries present different biomechanical behaviors and in this context, one arising question is how cuneiform implant geometry compares to clinical successful cylindrical threaded implant geometry. Purpose. The purpose of this work was to study stress distribution around cuneiform and cylindrical threaded implant geometries using three-dimensional finite element stress analysis taking the latter as a reference. Material and methods. A model was generated from a computerized tomography of a human edentulous mandible with implants placed in the left first premolar region. The model was supported by the mastication muscles and by temporomandibular joint. A vertical load of 100N was applied at the top of each implant in the direction of their long axes. The mandibular boundary conditions were modeled considering the actual muscle supporting system. Taking muscle forces intensities and directions, balance moment equations were employed to assess the system equilibrium. Cortical and medullary bones were assumed to be homogeneous, isotropic and linearly elastic. Results. The analysis provided results for maximum (S1) and minimum (S2) principal stress and Von Mises (SEQV) stress field. For both geometries, the results showed concentration on one side of the neck, smooth stress distribution along the body and no considerable concentration at the apical area. Conclusion. Results showed similar stress distribution pattern for cuneiform and cylindrical threaded geometries. The stresses profiles along the implants length reproduced their morphology. In both occurred stress concentration at one side of the neck and no body or apical stress concentration. PMID:17065763

Cruz, Mauro; Lourenço, Adelino Francisco; Toledo, Elson Magalhães; da Silva Barra, Luis Paulo; de Castro Lemonge, Afonso Celso; Wassall, Thomaz



Bilaterally impacted mandibular supernumerary premolars associated with unusual clinical complications.  


Supernumerary teeth are extra teeth in comparison to the normal dentition. Their prevalence varies between 0.1% and 3.8%. Supernumeraries are more common in permanent dentition and its incidence is higher in maxillary incisor region, followed by maxillary third molar and mandibular molar, premolar, canine, and lateral incisor. The prevalence of supernumerary premolars is between 0.075-0.26%, and they may occur in single or multiple numbers Bilateral occurrence is uncommon and large percentage of supernumerary premolars remains impacted, unerupted, and usually asymptomatic; radiograph plays an important role in diagnosis of these. The present paper reports a case of bilaterally impacted completely developed supernumerary premolars associated with common clinical complication in unusual manner along with taurodontism of the upper and lower molars. PMID:23833524

Pasha, Zameer; Choudhari, Sameer; Rathod, Azhar; Sulabha, A N



Bilaterally impacted mandibular supernumerary premolars associated with unusual clinical complications  

PubMed Central

Supernumerary teeth are extra teeth in comparison to the normal dentition. Their prevalence varies between 0.1% and 3.8%. Supernumeraries are more common in permanent dentition and its incidence is higher in maxillary incisor region, followed by maxillary third molar and mandibular molar, premolar, canine, and lateral incisor. The prevalence of supernumerary premolars is between 0.075-0.26%, and they may occur in single or multiple numbers Bilateral occurrence is uncommon and large percentage of supernumerary premolars remains impacted, unerupted, and usually asymptomatic; radiograph plays an important role in diagnosis of these. The present paper reports a case of bilaterally impacted completely developed supernumerary premolars associated with common clinical complication in unusual manner along with taurodontism of the upper and lower molars.

Pasha, Zameer; Choudhari, Sameer; Rathod, Azhar; Sulabha, A. N.



Mandibular movement restoration through bilateral coronoidectomy by intraoral approach.  


The present study aimed at reporting a clinical and surgical case of bilateral coronoidectomy, using an intraoral approach. The patient is a 26-year-old man, who sought attendance complaining of a gradual reduction of his oral opening in the past 3 years; however, he had an aggravation in the last 2 months. After clinical examination and imaging evaluation, the diagnosis of coronoid process hyperplasia was confirmed, and the surgical treatment was proposed. Under general anesthesia, with nasotracheal intubation guided by a nasofiberendoscope, using an intraoral approach, the bilateral coronoidectomy was performed. In the immediate postoperative period, an increase of the buccal opening measured 29 mm, representing an enhancement of 11 mm, and in the 30th postoperative day, it measured 31.12 mm. During the clinical follow-up period, a reestablishment of the mandibular movements was observed. Therefore, coronoidectomy by an intraoral approach and the physiotherapy performed in the postoperative period were efficient procedures. PMID:21558896

Ramalho-Ferreira, Gabriel; Faverani, Leonardo Perez; Fabris, André Luís da Silva; Pastori, Cláudio Maldonado; Magro-Filho, Osvaldo; Ponzoni, Daniela; Aranega, Alessandra Marcondes; Garcia-Júnior, Idelmo Rangel



Severe complication of a bonded mandibular lingual retainer.  


Bonding a flexible spiral wire retainer to the lingual surfaces of all 6 anterior mandibular teeth is a commonly used type of retention. Complications are rare but can be serious enough to produce biologic damage. This article presents a serious complication of a lingual flexible spiral wire retainer. Four years after the orthodontic treatment, a 20-year-old man sought treatment for a broken flexible spiral wire retainer. The clinical examination showed about 35° of buccal root torque of that tooth. A cone-beam computed tomography image showed that the root and the apex of the tooth were almost completely out of the bone on its buccal side. Surprisingly, the tooth's vitality was preserved. The tooth was moved back, nearly to its original position; clinically, only a gingival recession remained. Orthodontists and dentists should be aware of possible complications of bonded retainers. Patients should be clearly informed how to detect problems at an early stage. PMID:22920708

Pazera, Pawel; Fudalej, Piotr; Katsaros, Christos



Mandibular reconstruction in irradiated patients utilizing myosseous-cutaneous flaps  

SciTech Connect

Myosseous-cutaneous flaps were used for mandibular reconstruction in 16 irradiated patients. Three of six sternomastoid-clavicle flaps failed (all in conjunction with a neck dissection), as did one of 10 pectoralis major-anterior-fifth rib flaps. One trapezius-scapular flap was used and it succeeded. We found the blood supply of the sternomastoid-clavicle flap too tenuous for use in conjunction with a neck dissection. The trapezius-scapular flap had too short an arc of rotation to be used for defects other than those in the horizontal ramus. In addition, this flap required a change of position and created an undesirable functional deformity. The pectoralis major-fifth rib flap, in contrast, could be used for a variety of defects, in conjunction with a neck dissection, and did not require a change of position during operation. We found it to be the most versatile and dependable of the flaps employed in this series.

Pearlman, N.W.; Albin, R.E.; O'Donnell, R.S.



Root canal configuration of the mandibular first premolar.  


One hundred six human mandibular left and right first premolars, previously extracted due to nonrestorable caries, periodontal disease, or orthodontic reasons, were sectioned perpendicular to the long axis of the root starting at the cementoenamel junction. Three-millimeter sections were made with an ultrathin separating disc to the level of the anatomical apex. After 1 day in 5.25% NaOCl, each section was rinsed in phosphate-buffered saline, evaluated with a stereomicroscope, and photographed. The slides were projected and the shape of the canal, incidence of multiple canals, level of bifurcation, and any other variant anatomy were recorded. Seventy-six percent of the premolars demonstrated Type I canals and 24% contained Type IV. The shape of the canals was predominantly oval or round. An interesting finding was the number of C-shaped canals which were associated predominantly with Type IV canal systems. This occurred in 14% of the roots. PMID:1289476

Baisden, M K; Kulild, J C; Weller, R N



"C"-shaped canal configuration of mandibular second permanent molar.  


Roots of the second mandibular molar often fuse so the purpose of this investigation was to examine the appearance of "C"-shaped root canals and to classify different root canal types. A hundred and twelve randomly chosen second lower permanent molars-after extraction due to periodontal disease-were prepared and then analysed. Contrast liquid (methylene blue) was injected into prepared teeth. Each tooth was cut into slices to view the root canal morphology. Results of the analysis revealed fusion, either total or partial in 14 cases (12.5%). As a conclusion various appearances were classified into 5 types according to the fused canal shapes and the frequency of different types varied from 0.89%-6.25%. PMID:10097434

Sutalo, J; Simeon, P; Tarle, Z; Prskalo, K; Pevalek, J; Stanici?, T; Udovici?, M



Biomechanical effects of screw fixation in second mandibular reconstruction plate.  


The purpose of this study was to investigate biomechanical effects of second reconstruction plate with different combinations of fixed screws in patient with mandibular tumor resection by three-dimensional finite element analysis (FEA). The FEA models were consisted of defected mandible, reconstruction plate with different screw holes, and bone screws. The results indicated that application of the second reconstruction plate appeared to increase stability and decrease stress magnitude on the plates and screws accompanying with increasing screw number. For clinical cost consideration in usage of the second reconstruction plate, the conclusion showed that the second reconstruction plate could offer a better mechanical efficacy accompanying with increase of screw quantity, but single screw applied for the second plate fixation to defected mandible of tumor resection was enough to stabilize without increase of screw quantities. PMID:24110400

Chang, Ya-Wen; Liu, Pao-Hsin



MultiModality Surgical and Hyperbaric Management of Mandibular Osteoradionecrosis  

SciTech Connect

Purpose: To elucidate long-term outcomes in 65 consecutive patients meeting a uniform definition of mandibular osteoradionecrosis (ORN) treated with multimodality therapy including hyperbaric oxygen (HBO). Methods and Materials: Pretreatment, post-treatment and long-term follow-up of mandibular lesions with exposed bone were ranked by a systematic review of medical records and patient telephone calls. The ranking system was based on lesion diameter and number plus disease progression. Changes from pretreatment to post-treatment and follow-up were analyzed by Wilcoxon signed-rank tests. Improved wound survival, measured by time to relapse, defined as any less favorable rank after HBO treatment, was assessed by Kaplan-Meier analysis. Results: In all, 57 cases (88%) resolved or improved by lesion grade or progression and evolution criteria after HBO (p < 0.001). Four patients healed before surgery after HBO alone. Of 57 patients who experienced improvement, 41 had failed previous nonmultimodality therapy for 3 months and 26 for 6 months or more. A total of 43 patients were eligible for time-to-relapse survival analysis. Healing or improvement lasted a mean duration of 86.1 months (95% confidence interval [95% CI], 64.0-108.2) in nonsmokers (n = 20) vs. 15.8 months (95% CI, 8.4-23.2) in smokers (n = 14) versus 24.2 months (95% CI, 15.2-33.2) in patients with recurrent cancer (n = 9) (p = 0.002 by the log-rank method). Conclusions: Multimodality therapy using HBO is effective for ORN when less intensive therapies have failed. Although the healing rate in similarly affected patients not treated with HBO is unknown, the improvements seen with peri-operative HBO were durable provided that the patients remained cancer free and abstained from smoking.

Freiberger, John J., E-mail: freib002@mc.duke.ed [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC (United States); Yoo, David S. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Lisle Dear, Guy de [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC (United States); McGraw, Thomas A. [Department of Oral and Maxillofacial Surgery, Duke University Medical Center, Durham, NC (United States); Blakey, George H. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Oral and Maxillofacial Surgery, School of Dentistry, University of North Carolina, Chapel Hill, NC (United States); Padilla Burgos, Rebecca; Kraft, Kevin [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC (United States); Nelson, John W. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Moon, Richard E. [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC (United States); Piantadosi, Claude A. [Department of Anesthesiology, Duke University Medical Center, Durham, NC (United States); Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC (United States); Department of Medicine, Duke University Medical Center, Durham, NC (United States)



Ossifying fibroma affecting the mandibular condyle: report of an uncommon case.  


We describe the surgical management of an uncommon case of ossifying fibroma affecting the mandibular condyle. A condylectomy was performed with an immediate temporomandibular joint reconstruction by a total temporomandibular joint prosthesis. PMID:23851866

Zavattero, Emanuele; Garzino-Demo, Paolo; Berrone, Sid



Anatomical and histological features of C-shaped canals in mandibular second molars.  


The mandibular second molar has many root canal variations. This investigation used two evaluation methods to examine the canal morphology of mandibular second molars having C-shaped canals. Fifteen extracted mandibular second molars with a conical root and C-shaped canal orifice were separated into two groups. A polyester cast resin technique allowed three-dimensional visualization of the root canal system in eight teeth; the remaining seven molars were prepared for histological examination in cross-section in the coronal, middle, and apical thirds for study under the light microscope. The results illustrated that C-shaped canals in mandibular second molars can vary in number and shape along the length of the root with the result that debridement, obturation, and restoration in this group may be unusually difficult. PMID:1809802

Melton, D C; Krell, K V; Fuller, M W



Endodontic Treatment of a Mandibular Second Molar with Two Mesial Roots: Report of a Case  

PubMed Central

A case of unusual root morphology is presented to demonstrate anatomic variations in mandibular second molars. The most common configuration of mandibular second molar is to have two roots with three root canals; however mandibular molars may have many different combinations. Endodontic therapy was performed in a mandibular second molar with 3 separate roots 2 located mesially and one distally. Radiographically all 3 root canals terminated with individual foramina. Three orifices or 3 independent canals were found in the 3 separate roots, indicating a rare anatomic configuration. Looking for additional roots, canals and unusual morphology is an important part of successful endodontics as the knowledge of their existence occasionally enable clinicians to treat a case that otherwise might have ended in failure.

Ravanshad, Shohreh; Nabavizade, Mohammad Reza



Endodontic Management of Mandibular First Molar with Middle Distal Canal: A Case Report  

PubMed Central

The knowledge of variations in root canal morphology is critical for a successful endodontic treatment. This article presents the endodontic management of a unique case of mandibular molar with middle distal canal which is quite uncommon.

Venumuddala, Vijay Reddy; Sridhar, M.; Rajasekaran, M.; Poorni, Saravanan; Senthilkumaran, Gnanaprakasam



Relationship Between the Number of Rat Littermates per Dam and Mandibular Incisor Growth  

Microsoft Academic Search

The relationship between the number of littermates per dam and tooth growth of the mandibular incisor taken out of occlusion by experimental shortening was investigated. The variation in eruptive growth was statistically significant.

Miguel C. Madeira; Sebastião Hetem; Mauro A. Rulli



A rare presentation of dens in dente in the mandibular third molar with extra oral sinus.  


The unusual case of dense in dente in mandibular molar area with extra oral sinus in a 30-year-old female is presented. The chief complaint of the patient was wound formation and pus discharge from the right side of lower jaw for many years. Clinical examination revealed extra oral sinus and mild swelling in vestibular region opposite the right mandibular molars. On radiographical examination, right mandibular third molar had bulbous root associated with periapical radiolucency. It appeared that there was a tooth within a tooth and the invagination extended nearly to the root apex. A clinical diagnosis of dense in dente Type III was confirmed by stereomicroscopy of ground section of the tooth. Extra oral sinus healed after extraction of the mandibular third molar within a month. PMID:21731269

Bansal, Monika; Singh, Nn; Singh, Anand Pratap



Regional odontodysplasia. A case associated with asymmetric maxillary and mandibular development.  


Regional odontodysplasia is an uncommon condition of variable expression and unknown etiology. A case of unilateral maxillary regional odontodysplasia associated with asymmetric maxillary and mandibular development and consequent facial asymmetry is reported. PMID:1656359

Pandis, N; Polido, C; Bell, W H



An Investigation of Three types of Tooth Implant Supported Fixed Prosthesis Designs with 3D Finite Element Analysis  

PubMed Central

Objective: Tooth/implant supported fixed prostheses may present biomechanical design problems, as the implant is rigidly anchored within the alveolus, whereas the tooth is attached by the periodontal ligament to the bone allowing movement. Many clinicians prefer tooth/implant supported fixed prosthesis designs with rigid connectors. However, there are some doubts about the effect of attachment placement in different prosthesis designs. The purpose of this study was to examine the stresses accumulated around the implant and natural teeth under occlusal forces using three dimensional finite element analysis (3D FEA). Materials and Methods: In this study, different connection designs of tooth/implant fixed prosthesis in distal extension situations were investigated by 3D FEA. Three models with various connection designs were studied; in the first model an implant rigidly connected to an abutment, in the second and third models an implant connected to abutment tooth with nonrigid connector in the distal part of the tooth and mesial part of the implant. In each model, a screw type implant (5×11mm) and a mandibular second premolar were used. The stress values of these models loaded with vertical forces (250N) were analyzed. Results: There was no difference in stress distribution around the bone support of the implant. Maximum stress values were observed at the crestal bone of the implant. In all models, tooth movement was higher than implant movement. Conclusion: There is no difference in using a rigid connector, non rigid connector in the distal surface of the tooth or in the mesial surface of an implant.

Koosha, Sara; Mirhashemi, Fatemeh Sadat



Endodontic management of permanent mandibular left first molar with six root canals.  


The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and clinically challenging. This case report presents the treatment of a mandibular first molar with six root canals, of which three canals were located in the mesial root and three in distal root. Third canals were found between the two main root canals. This case presents a rare anatomic configuration and points to the importance of expecting and searching for additional canals. PMID:22629055

Gupta, Sachin; Jaiswal, Shikha; Arora, Rohit



cDNA cloning of a mandibular organ inhibiting hormone from the spider crab Libinia emarginata  

Microsoft Academic Search

Mandibular organs (MO) produce a crustacean juvenile hormone, methyl farnesoate (MF). MO activity is negatively regulated\\u000a by factors, called mandibular organ inhibiting hormones (MOIHs), from the crustacean sinus gland X-organ complex in the eyestalks.\\u000a Three MOIHs have been isolated previously from the spider crabLibinia emarginata and are characterized as members of the crustacean hyperglycemic hormone (CHH) neuropeptide family. In the

Lei Liu; Hans Laufer; Peter J. Gogarten; Minhua Wang



Comparison of Mandibular Phenotypic and Genetic Integration between Baboon and Mouse  

Microsoft Academic Search

In this study we compare patterns of mandibular integration between mice and baboons using both phenotypic and quantitative\\u000a genetic data. Specifically, we test how well each species fits with the mosaic model of mandibular integration suggested by\\u000a Atchley and Hall (Biol Rev Camb Philos Soc 66:101–157, 1991) based on developmental modules. We hypothesize that patterns\\u000a of integration will be similar

Katherine E. Willmore; Charles C. Roseman; Jeffrey Rogers; James M. Cheverud; Joan T. Richtsmeier



Preliminary optical coherence tomography investigation of the temporo-mandibular joint disc  

Microsoft Academic Search

Aim and objectives. The morphology and position of the temporo-mandibular disc are key issues in the diagnosis and treatment of arthrogenous temporo-mandibular disorders. Magnetic resonance imaging and arthroscopy are used today to identify: flattening of the pars posterior of the disc, perforation and\\/or adhesions in the pars intermedia of the disc and disc displacements. The present study proposes the investigation

Corina Marcauteanu; Enikö Demjan; Cosmin Sinescu; Meda Negrutiu; Adrian Motoc; Rodica Lighezan; Liliana Vasile; Mike Hughes; Adrian Bradu; George Dobre; Adrian G. Podoleanu



Can mouthguards prevent mandibular bone fractures and concussions? A laboratory study with an artificial skull model.  


Some sports' accidents are responsible for inflicting traumatic brain injuries and mandibular bone fractures when impacts occur to the chin. It is often thought that mouth guards can prevent many of these injuries. However, such assertions may be insufficient without adequate research. It is therefore necessary to establish a systematic method of investigation to solve this problem. In the present laboratory study, tests were performed using pendulum impact equipment and an artificial skull model connected to strain gages and accelerometers to simulate and measure the surface distortions related to bone deformation or fractures and the acceleration of the head related to concussions. As impacts, direct blows to the mandibular undersurface were applied. As a result, wearing a mouth guard decreased (P < 0.01) the distortion to the mandibular bone and the acceleration of the head significantly compared with not wearing a mouth guard (54.7%: to the mandible -- measured at a total of three different points, 18.5%: to the head measured at a total of three different points). Within the limits of this study, the following conclusions were drawn: The present measuring system in this study was able to evaluate the distortion to the mandibular and the acceleration of the head from the direct blow to the mandibular undersurface. Mouth guards can reduce distortion to the mandibular and the acceleration of the head from the same blow. So mouth guards might have the possibility to prevent mandibular bone fractures and concussions. However, further well-designed and exhaustive studies are vital to show that mouth guards reduce the incidence of concussions and mandibular bone fractures. PMID:15876323

Takeda, Tomotaka; Ishigami, Keiichi; Hoshina, Sanae; Ogawa, Toru; Handa, Jun; Nakajima, Kazunori; Shimada, Atsushi; Nakajima, Tsuneya; Regner, Connell Wayne



Bilateral mandibular distraction for patients with compromised airway analyzed by three-dimensional CT  

Microsoft Academic Search

The purpose of this study was to present the method of mandibular distraction osteogenesis in order to improve airway to respiratory distressed patients due to significant mandibular deficiency, and to present the quantitative volumetric evaluation of mandible and upper airway using three-dimensional-CT (3D-CT) before and after distraction.This study involved 12 patients aged 12 months to seven years with various complaints

A. Rachmiel; D. Aizenbud; G. Pillar; S. Srouji; M. Peled



Clinical survey of neurosensory side-effects of mandibular parasymphyseal bone harvesting  

Microsoft Academic Search

The aim of the present survey was to assess neurosensory disturbances and\\/or tooth-pulp sensitivity losses after mandibular parasymphyseal bone-harvesting procedures. Twenty-eight harvesting areas in 16 patients were surveyed. Mucosal and skin sensitivity of the chin\\/lower lip, divided into four regions, were determined via Pointed-Blunt and Two-Point-Discrimination Tests. Pulp sensitivity of the mandibular teeth from the left second bicuspid to the

L. Sbordone; G. B. Menchini-Fabris; P. Toti; C. Sbordone; L. Califano; F. Guidetti



The extremely resorbed mandible, 10-year results of a randomized controlled trial on 3 treatment strategies.  


OBJECTIVES: To prospectively compare the clinical and radiographic results of three modes of implant treatment for implant-retained mandibular overdentures in patients with extremely resorbed mandibles. The three treatment strategies used were (1) a transmandibular implant, (2) augmentation of the mandible with an autologous bone graft followed by placement of four endosseous implants, and (3) placement of four short endosseous implants. MATERIALS AND METHODS: Sixty edentulous patients met the inclusion criteria and were assigned according to a balanced allocation method to 1 of the 3 treatment strategies. Implant survival, surgical retreatment rates, and peri-implant bone loss were assessed according to a standardized protocol during a 10-year evaluation period. RESULTS: During the evaluation period, significantly more implants were lost in the transmandibular implant (cumulative 10-year implant survival rate, 76.3%) and the augmentation groups (88%) compared to the group provided with short endosseous implants (98.8%). The 10-year retreatment rate was significantly more favorable in the endosseous implants only (0%) and augmentation groups (5%) compared to the transmandibular group (30%). In all three groups, there was minor peri-implant bone loss. DISCUSSION: Although implant loss is a frequently used outcome measure for success, the necessity of surgical retreatment seems to be of more relevance for both the patient and the clinician. CONCLUSION: Considering the favorable clinical and radiographic parameters and the fact that patients can be treated in outdoor clinic setting, the use of short endosseous implants in combination with an overdenture is the first choice of treatment in patients with extremely resorbed mandibles. PMID:23638947

Stellingsma, Kees; Raghoebar, Gerry M; Visser, Anita; Vissink, Arjan; Meijer, Henny J A



Root Canal Configuration of Mandibular First and Second Premolars in an Iranian Population  

PubMed Central

Background and aims It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The aim of this study was to determine the canal configuration and the prevalence of C-shaped canals in mandibular first and second premolars in a North-Western Iranian population. Materials and methods A total of 163 extracted mandibular first and 103 mandibular second premolars were injected with India ink and demineralized . They were made clear and transparent with methyl salicylate and the anatomy of their canal(s) was studied. Results The results showed that 98% of mandibular first premolars had one root, 2% had two roots, 70.6% had one canal, 27.8% had two canals, 1.2% had three canals and the prevalence of C-shaped canals was 2.4%. All mandibular second premolars had one root, 80.5% had one canal, 17.5% had two canals and the prevalence of C-shaped canals was 2%. Conclusion It is important that clinicians, before treatment of mandibular first and second premolars, pay complete attention to radiographs, have a true concept of the number of root(s) and canal(s), and prepare a correct access cavitiy.

Rahimi, Saeed; Shahi, Shahriar; Yavari, Hamid Reza; Manafi, Hakimeh; Eskandarzadeh, Nemat



Distal movement of mandibular molars in adult patients with the skeletal anchorage system.  


The skeletal anchorage system (SAS) consists of titanium anchor plates and monocortical screws that are temporarily placed in either the maxilla or the mandible, or in both, as absolute orthodontic anchorage units. Distalization of the molars has been one of the most difficult biomechanical problems in traditional orthodontics, particularly in adults and in the mandible. However, it has now become possible to move molars distally with the SAS to correct anterior crossbites, maxillary dental protrusion, crowding, and dental asymmetries without having to extract premolars. This study evaluated the treatment and posttreatment changes during and after distalization of the mandibular molars. In 15 adult patients (12 women and 3 men), a total of 29 mandibular molars were successfully distalized with SAS. The amount of distalization and relapse and the type of tooth movement were analyzed with cephalometric radiographs and dental casts. The average amount of distalization of the mandibular first molars was 3.5 mm at the crown level and 1.8 mm at the root level. The average amount of relapse was 0.3 mm at both the crown and root apex levels. Of 29 mandibular molars, 9 were tipped back, and the others were translated distally in accordance with the established treatment goals. SAS is a viable modality to move mandibular molars for distally correcting anterior crossbites, malocclusions characterized by mandibular anterior crowding, and dental asymmetries. PMID:14765050

Sugawara, Junji; Daimaruya, Takayoshi; Umemori, Mikako; Nagasaka, Hiroshi; Takahashi, Ichiro; Kawamura, Hiroshi; Mitani, Hideo



Bilateral mandibular distraction for patients with compromised airway analyzed by three-dimensional CT.  


The purpose of this study was to present the method of mandibular distraction osteogenesis in order to improve airway to respiratory distressed patients due to significant mandibular deficiency, and to present the quantitative volumetric evaluation of mandible and upper airway using three-dimensional-CT (3D-CT) before and after distraction. This study involved 12 patients aged 12 months to seven years with various complaints of Obstructive Sleep Apnea (OSA) such as noisy breathing during sleep, waking episodes, pauses in respiration and daytime somnolence. Some of them were considered tracheostomy candidates. All the patients underwent bilateral mandibular distraction under general anesthesia. 3D-CT of face and neck was performed before and after distraction and a quantitative volumetric evaluation of mandibular volume and airway volume was performed. The results reveal successful mandibular advancement with increase of mandibular volume by an average of 28.24% and increase of upper airway volume with a mean of 71.92%. Moreover, there were improved apnea index and oxygen saturation and elimination of OSA symptoms. In conclusion, the results demonstrate that following distraction osteogenesis of hypoplastic mandible the volume of the mandible and upper airway increases, eliminating symptoms of OSA and preventing tracheostomy. PMID:15617961

Rachmiel, A; Aizenbud, D; Pillar, G; Srouji, S; Peled, M



Considerations of mandibular angle fractures during and after surgery for removal of third molars: a review of the literature  

Microsoft Academic Search

Background  Angle fractures are quite common considering that the angle of the mandible forms an area of lower resistance which contains\\u000a a thicker upper border, a thin basilar bone, and the presence of an impacted mandibular third molar. Common complications\\u000a of mandibular third molar surgery include alveolar osteitis (dry socket), secondary infection, nerve dysfunction, and hemorrhage.\\u000a Reports of mandibular fracture during

Bruno Ramos Chrcanovic; Antônio Luís Neto Custódio



Alveolar Ridge Preservation Prior to Implant Placement with Surgical-Grade Calcium Sulfate and Platelet-rich Plasma: A Pilot Study in a Canine Model  

Microsoft Academic Search

Purpose: To evaluate the combination of surgical-grade calcium sulfate (SGCS) and platelet-rich plasma (PRP) for alveolar ridge preservation prior to implant placement. Materials and Methods: Five mongrel dogs were used as subjects. Four enlarged mandibular extraction sockets, 2 on each side, were created in each dog. According to a split-mouth design, the 2 anterior sockets received either SGCS\\/PRP (SGCS\\/PRP ant)

Bin Shi; Yi Zhou; Yi Ning Wang; Xiang Rong Cheng


Implants in adolescents.  


Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature. PMID:24174743

Shah, Rohit A; Mitra, Dipika K; Rodrigues, Silvia V; Pathare, Pragalbha N; Podar, Rajesh S; Vijayakar, Harshad N



Implants in adolescents  

PubMed Central

Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature.

Shah, Rohit A.; Mitra, Dipika K.; Rodrigues, Silvia V.; Pathare, Pragalbha N.; Podar, Rajesh S.; Vijayakar, Harshad N.



Hydrogen implanted silicon oxidation  

Microsoft Academic Search

The oxidation rate and the oxide thickness of the hydrogen ion implanted silicon wafers were examined. It was observed that\\u000a the native oxide thickness is higher for the H+ implanted Si(100) compared to the Si(111). Also the native oxide thickness depended on the implanted hydrogen distribution.\\u000a The thickness increased with the hydrogen con-centration. The oxide thickness after wet oxidization of

S. Hava; B. M. Lacquet; P. L. Swart



The immediate dental implant.  


Numerous clinical studies have shown that dental implants can be placed immediately in extraction sockets with success when sites are carefully selected. Dental implants have been placed at the time of extraction with a variety of techniques. All the techniques report survival rates of 94 percent to 100 percent over a varied healing period of three months to approximately seven years. this article will review clinical criteria for determining patient selection for immediate implants and the advantages and disadvantages of immediate implant placement. PMID:12041804

Douglass, Gordon L; Merin, Robert L



Rationale for tilted implants: FEA considerations and clinical reports  

PubMed Central

SUMMARY The prevalence of the elderly population, as well as life expectancy, increased in the final decades of the 20th century, as described in the World Health Organization 2004 Annual Report. The edentulous condition therefore has a negative impact on the oral health–related quality of life. Patients wearing complete dentures for many years infact, and especially in the mandible, are often unsatisfied because of the instability of the prosthesis during speaking and eating. To date dental implant treatment is well documented as a predictable treatment for partial or complete edentulism. On the other hand the rehabilitation of atrophied edentulous arches with endosseous implants (> 10 mm) in the posterior regions is often associated with anatomic problems such as bone resorption, poor bone quality, mandibular canal, and the presence of maxillary sinuses. Different procedures have been proposed to overcome these anatomic limitations. The use of tilted implants parallel to the anterior wall of the maxillary sinus or the mental foramen/inferior alveolar nerve has been proposed as a conservative solution for the treatment of the atrophic edentulous maxilla. Aim of this study was to describe, through a detailed literature review, the clinical and biomechanical rationale for tilting implants and to evaluate the long-term prognosis of immediately loaded full fixed prostheses for the treatment of edentulous patients (#35) with extreme bone atrophy rehabilited with both axial (#70) and tilted (#70) implants from 2008 to 2010. The results of the present study would suggest that this new surgical technique may reduce patient morbidity and extend the indications for immediate loading full fixed rehabilitations. This improves the predictability of treatment goal, allows for a better risk management, and provides more individual information for the patient. These are the most important aspects of this technology, which may contribute to establish higher-quality standards in implantology.




Root and canal morphology of permanent mandibular molars in a Sri Lankan population.  


The main purpose of this study was to investigate the root and canal morphology of Sri Lankan mandibular molars and to determine the affinities of these morphological variations to those of people of European and Asian origin. Two hundred mandibular first and second molars were examined. The number of roots and the prevalence of C-shaped (gutter-shaped) roots in mandibular second molars were recorded. Root canal morphology was studied using a clearing technique. The examination of root canal systems of the teeth was based on Vertucci's classification. Among mandibular first molars, only 3% had three roots. Mesial roots of the first molar typically presented with two canals and two apical foramina with type IV, V, or VI canal configuration. Most distal roots of the first molar presented with a type I canal configuration. The remainder were distributed mainly between types III and V. Among mandibular second molars, 6% had single C-shaped roots, while C-shaped canals were found in only 2%. The majority of mesial roots of the second molar showed one or two canals, with one apical foramen with type I, II, or III canal morphology. In addition, the distal root commonly showed type I canal configuration. Intercanal communications and lateral canals were more frequently seen in the first molar than in the second. The root canal morphology in mandibular molars varies among population groups. Mandibular root and canal morphology of Sri Lankan people has closer affinities with that of people of European than of East Asian origin. PMID:17660977

Peiris, Roshan; Takahashi, Masami; Sasaki, Kayoko; Kanazawa, Eisaku



Morphogenesis and bone integration of the mouse mandibular third molar.  


The mouse third molar (M3) develops postnatally and is thus a unique model for studying the integration of a non-mineralized tooth with mineralized bone. This study assessed the morphogenesis of the mouse M3, related to the alveolar bone, comparing M3 development with that of the first molar (M1), the most common model in odontogenesis. The mandibular M3 was evaluated from initiation to eruption by morphology and by assessing patterns of proliferation, apoptosis, osteoclast distribution, and gene expression. Three-dimensional reconstruction and explant cultures were also used. Initiation of M3 occurred perinatally, as an extension of the second molar (M2) which grew into a region of soft mesenchymal tissue above the M2, still far away from the alveolar bone. The bone-free M3 bud gradually became encapsulated by bone at the cap stage at postnatal day 3. Osteoclasts were first visible at postnatal day 4 when the M3 came into close contact with the bone. The number of osteoclasts increased from postnatal day 8 to postnatal day 12 to form a space for the growing tooth. The M3 had erupted by postnatal day 26. The M3, although smaller than the M1, passed through the same developmental stages over a similar time span but showed differences in initiation and in the timing of bone encapsulation. PMID:21726286

Chlastakova, Ivana; Lungova, Vlasta; Wells, Kirsty; Tucker, Abigail S; Radlanski, Ralf J; Misek, Ivan; Matalova, Eva



Management of middle mesial canal in mandibular second molar  

PubMed Central

The primary objective of endodontic therapy is to achieve a three-dimensional obturation of the root canal space after adequate preparation of the canal space to remove the tissue debris, microorganisms, and their byproducts. Anatomical variations have frequently been encountered in endodontic practice and have to be adequately managed by the clinician. Missed roots and canals are a major reason for failure of therapy. Technological advances have given the clinician ample opportunity to identify and treat these aberrations successfully. The present report describes a left mandibular second permanent molar requiring root canal treatment, found to have three separate canals in the mesial root. This case demonstrates a rare anatomical configuration and emphasizes the need for the clinician to be aware of and look out for such variations and use adequate diagnostic methodologies prior to and during therapy to detect such variations. The possibility of additional canals, whenever in doubt, should be explored with the assistance of technologies such as those of magnification and illumination and various diagnostic aids. Operator experience has also shown to be a key factor in negotiation and management of these aberrant canal configurations.

Karunakaran, J. V.; Shobana, R.; Kumar, Mohan; Kumar, Senthil; Mankar, Sunil



The mandibular incisor: rethinking guidelines for post and core design.  


In post and core research, little attention has been given to the tooth with minimal bulk and mesialdistal width. The purpose of this in vitro study was to investigate retention and fracture characteristics of lower incisors restored with variable dowel designs. Fifty freshly extracted mandibular incisors were endodontically treated. Four groups of 10 teeth, decoronalized and dowel- and core-restored, were tested for retention characteristics and fracture resistance. One group of 10 teeth restored with composite resin in intact natural crown acted as controls. Dowel variables included a prefabricated round cross-sectional design and a morphologic dowel that reproduced the canal space. A universal testing machine created tensile and transverse loads, and failure was measured and recorded. Results showed no difference in resistance to transverse loading between morphological and standardized dowels (p > 0.05). However, when analyzing modes of failure, ferruled morphological post and core design was less likely to result in a catastrophic root or post fracture. In addition, morphological dowels were significantly more retentive than standardized round dowels in teeth with narrow cross-sections (p = 0.007). This study also reaffirmed the findings of previous investigations, that the intact natural crown of an endodontically treated tooth provides maximum resistance to root fracture. PMID:7714432

Gluskin, A H; Radke, R A; Frost, S L; Watanabe, L G



Study of mandibular kinetics by COSIG. Computerized sirognathograph system.  


Several programs for coupling Sirognathograph to personal computer are available on the market (Maruyama's SGG Analyzing System Radke's Bio-Pac-Software, Fabris's Computersystem for Sirognathograph S) or are in various non commercial versions used in research (Lewin, Micheler, Proeschel). The COSIG System consists of the software and the hardware (Sirognathograph S--Siemens, XY 575 Recorder Esterline Angus, Personal computer IBM XT, IBM Graphics, Printer, A/D converter Tecmar Labmaster, Roland Plotter 880 DXY). The COSIG software records simultaneously X, Y, Z data from SGG, store and retrieve them. Mandibular movements are presented in time plot mode, in the three planes, in speed and acceleration plots, using different magnifications, direction color code, deliberate observation times, enables zero adjustments and storing of particular situation with comments on it within the file. Simultaneously graphic presentation goes by XY recorder, while stored data are screen printed by Graphic printer or color and black and white plotted by XY plotter. Standard patient examination using COSIG comprises three files i.e. border movement potential, contact movements and chewing standard bolus has been proposed. PMID:2408134

Marion, L; Ahlin, A; Kopac, I



Evolution of the mandibular third premolar crown in early Australopithecus.  


The Pliocene hominins Australopithecus anamensis and Australopithecus afarensis likely represent ancestor-descendent taxa--possibly an anagenetic lineage--and capture significant change in the morphology of the canine and mandibular third premolar (P(3)) crowns, dental elements that form the canine honing complex in nonhuman catarrhines. This study focuses on the P(3) crown, highlighting plesiomorphic features in A. anamensis. The A. afarensis P(3) crown, in contrast, is variable in its expression of apomorphic features that are characteristic of geologically younger hominins. Temporal variation characterizes each taxon as well. The A. anamensis P(3) from Allia Bay, Kenya expresses apomorphic character states, shared with A. afarensis, which are not seen in the older sample of A. anamensis P(3)s from Kanapoi, Kenya, while spatiotemporal differences in shape exist within the A. afarensis hypodigm. The accumulation of derived features in A. afarensis results in an increased level of P(3) molarisation. P(3) molarisation did not evolve concurrent with postcanine megadontia and neither did the appearance of derived aspects of P(3) occlusal form coincide with the loss of canine honing in hominins, which is apparent prior to the origin of the genus Australopithecus. A. afarensis P(3) variation reveals the independence of shape, size, and occlusal form. The evolution of the P(3) crown in early Australopithecus bridges the wide morphological gap that exists between geologically younger hominins on the one hand and extant apes and Ardipithecus on the other. PMID:21481921

Delezene, Lucas K; Kimbel, William H



Lithium Implantation into Fullerite  

Microsoft Academic Search

The depth profiles of lithium, implanted into fullerene at different fluences and temperatures are reported. They deviate considerably from the simple ballistic predictions. They can be understood in terms of depth dependent Li mobility immediately after the ion implantation. This mobility depends considerably on the temperature and on the degree of fullerene damage. It appears that the fullerene destruction products

D. Fink; S. Ghosh; R. Klett; L. Palmetshofer; J. Vacik; V. Hnatowicz; J. Cervena; J. Kaschny; F. C. Zawislak; P. Sanchez; M. Behar



A no bleed implant.  


Breast implants have evolved from the original saline-filled, smooth-surfaced silicone rubber bag to silicone gel-filled smooth-walled sacs to a combination of a silicone gel-filled bag within a saline-filled sac, and, most recently, a reversed, double-lumen implant with a saline bag inside of a gel-filled bag. Texture-surfaced implants were first used in 1970 when the standard silicone gel-filled implant was covered with a polyurethane foam. Because of concerns about the degradation products of this foam, they were removed from the market in 1991. In 1975 double-lumen silicone textured implants were developed, followed by silicone gel-filled textured implants. In 1990 a new radiolucent, biocompatible gel was produced that reduced the problem of radioopacity of silicone implants. Because of the gel's sufficiently low coefficient of friction, leakage caused by fold flaw fracture may also be decreased. We present a case where this new biocompatible gel implant was repositioned after four months. The resulting scar capsule in this soft breast was thin [< 0.002 cm (0.008 in.)] and evenly textured as a mirror image of the textured silicone surface. Scanning electron microscopy and x-ray defraction spectrophotometry revealed no silicone bleed. PMID:8213316

Ersek, R A; Navarro, J A; Nemeth, D Z; Sas, G



Implantable CMOS Biomedical Devices.  


The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented. PMID:22291554

Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko



Gold bead implants.  


Gold bead implantation is an experimental area of study in the acupuncture field dealing with chronic diseases. Special acupuncture techniques are required to implant the gold beads successfully in the proper location. Gold beads are used to treat degenerative joint disease, osteochondritis, osteochondritis dessicans, ventral spondylosis, and seizures. PMID:1581658

Durkes, T E



Implantate in avaskulären Beckenknochentransplantaten  

Microsoft Academic Search

Zusammenfassung Der Verlust des Alveolarfortsatzes im Ober- und Unterkiefer setzt Knochenersatzplastiken voraus, um die kaufunktionelle Rehabilitation über alloplastische Zahnwurzelimplantate zu ermöglichen. Mit dieser Arbeit soll geklärt werden, wie hoch die langfristige Liegerate dentaler Implantate ist, die in avaskulär transplantierten Beckenknochen-Onlays inseriert werden, und ob und in welchem Umfang ein einzeitiges oder zweizeitiges Vorgehen die Prognose der Implantate beeinflußt. In einer

H. E. Umstadt; J. Völlinger; H.-H. Müller; K. H. Austermann



Packaging of Implantable Microsystems  

Microsoft Academic Search

Challenges and technologies for long-term stable packaging of implantable devices and microsystems are reviewed. Packaging of implantable microsystems is especially difficult because of the many limitations in terms of size, material properties, mechanical structure and rigidity, biocompatibility, required lifetime, and maximum allowable temperature. Our group has demonstrated their long-term reliability in salt water and biological environments. Glass packages anodically bonded

Khalil Najafi



Implantable cardioverter defibrillators  

Microsoft Academic Search

The electrical design challenges for implantable defibrillators are discussed based on the following criteria: device evolution, system architecture, therapy delivery, mid heart activity sensing circuits. The discussion includes the incidence of sudden cardiac death and the clinical requirements of device hardware. System architecture includes the three dependent entities that define the system mid the functional components of the implanted device




Variations of the mandibular shape in extant hominoids: Generic, specific, and subspecific quantification using elliptical fourier analysis in lateral view.  


While a number of studies have documented the mandibular variations in hominoids, few focused on evaluating the variation of the whole outline of this structure. Using an efficient morphometrical approach, i.e. elliptical Fourier analysis, mandibular outlines in lateral view from 578 adult hominoids representing the genera Hylobates, Pongo, Gorilla, Pan, and Homo were quantified and compared. This study confirms that elliptical Fourier analysis provides an accurate characterization of the shape of the mandibular profile. Differences in mandibular shape between hominoid genera, species, subspecies, and to a lesser extent between sexes were demonstrated. Mandibles in great apes and hylobatids subspecies were generally less distinct from each other than were species. However, the magnitudes of differences among subspecies of Gorilla and Pongo approached or exceeded those between Pan troglodytes and P. paniscus. The powerful discrimination between taxa from the genus down to subspecific level associated to the relatively low level of intrageneric mandibular polymorphism in great apes provides strong evidences in support of the taxonomic utility of the shape of the mandibular profile in hominoids. In addition, morphological affinities between Pongo and Pan and the clear distinction between Homo and Pan suggest that the mandibular outline is a poor estimate of phylogenetic relationships in great apes and humans. The sexual dimorphism in mandibular shape exhibits two patterns of expression: a high degree of dimorphism in Gorilla, Pongo, and H. s. syndactylus and a relatively low one in modern humans and Pan. Besides, degree of mandibular shape dimorphism can vary considerably among closely related subspecies as observed in gorillas, arguing against the use of mandibular shape dimorphism patterns as characters in phylogenetic analyses. However, the quantification of the mandibular shape and of the variations among hominoids provides an interesting comparative framework that is likely to supply further arguments for a better understanding of the patterns of differentiation between living hominoids. PMID:17063462

Schmittbuhl, Matthieu; Rieger, Jean; Le Minor, Jean-Marie; Schaaf, André; Guy, Franck



Dislocation of the mandibular condyle into the middle cranial fossa causing an epidural haematoma.  


Dislocation of the mandibular condyle into the middle cranial fossa is a rare complication of mandibular trauma due to anatomical and biomechanical factors. Owing to the proximity of the temporal glenoid fossa to the middle meningeal artery, there is the risk of serious sequelae in case of trauma. The authors report the case of a 36-year-old male patient, who was beaten up in a family dispute and presented with complex mandibular and maxillofacial fractures, including mandibular condyle intrusion into the middle cranial fossa causing extensive meningeal bleeding. The patient underwent immediate surgery, with evacuation of the epidural haematoma via a temporal approach. In addition open reduction and reconstruction of the temporal glenoid fossa via anatomic reduction of the fragments was performed. A functional occlusion was re-established via miniplate reconstruction of the complex mandibular body and ramus fractures. Prompt diagnosis and a multidisciplinary approach are essential to minimize the complications. Advanced imaging modalities of computed tomography are indicated. Treatment options should be individualized in particular in case of suspected neurological injury. PMID:21862340

Struewer, Johannes; Kiriazidis, Ilias; Figiel, Jens; Dukatz, Thomas; Frangen, Thomas; Ziring, Ewgeni



Association between mandibular posterior alveolar morphology and growth pattern in a Chinese population with normal occlusion*  

PubMed Central

Objective: To investigate the relationship between growth patterns and mandibular posterior tooth-alveolar bone complex morphology in a Chinese population with normal occlusion. Methods: Forty-five patients with normal occlusion (23 males, 22 females) were included in this study. Among these patients, 20 displayed the vertical growth pattern, and 20 had the horizontal growth pattern, while the remaining patients displayed the average growth pattern. All of the patients underwent dental cone beam computed tomography (CBCT), which included the region of the mandibular posterior teeth and the alveolar. A linear regression analysis and a correlation analysis between the facial height index (FHI) and the alveolar bone morphology were performed. Results: The inclination of the molars, the thickness of the cortical bone, and the height of the mandibular bone differed significantly between patients with the horizontal growth pattern and those with the vertical growth pattern (P<0.05). Significant positive correlations were found between: the FHI and the inclination of the molars; the FHI and the thickness of the cortical bone; and the FHI and the height of the mandibular bone. Conclusions: The mandibular posterior tooth-alveolar bone complex morphology may be affected by growth patterns.

Han, Min; Wang, Rong-yang; Liu, Hong; Zhu, Xiu-juan; Wei, Fu-lan; Lv, Tao; Wang, Na-na; Hu, Li-hua; Li, Guo-ju; Liu, Dong-xu; Wang, Chun-ling



Mesodermal and neural crest derived ovine tibial and mandibular osteoblasts display distinct molecular differences.  


Mandibular osteoblasts originate from the neural crest and deposit bone intramembranously, mesoderm derived tibial osteoblasts by endochondral mechanisms. Bone synthesized by both cell types is identical in structure, yet functional differences between the two cell types may exist. Thus, both matched juvenile and adult mandibular and tibial osteoblasts were studied regarding their proliferative capacity, their osteogenic potential and the expression of osteogenic and origin related marker genes. Juvenile tibial cells proliferated at the highest rate while juvenile mandibular cells exhibited higher ALP activity depositing more mineralized matrix. Expression of Hoxa4 in tibial cells verified their mesodermal origin, whereas very low levels in mandibular cells confirmed their ectodermal descent. Distinct differences in the expression pattern of bone development related genes (collagen type I, osteonectin, osteocalcin, Runx2, MSX1/2, TGF-?1, BAMBI, TWIST1, ?-catenin) were found between the different cell types. The distinct dissimilarities in proliferation, alkaline phosphatase activity, the expression of characteristic genes, and mineralization may aid to explain the differences in bone healing time observed in mandibular bone when compared to long bones of the extremities. PMID:23632238

Reichert, J C; Gohlke, J; Friis, T E; Quent, V M C; Hutmacher, D W



Anatomical study of C-shaped canals in mandibular second molars by analysis of computed tomography.  


The aim of this study was to investigate the prevalence and configuration of the C-shaped canal using serial axial computed tomography images of the mandibular second molars that had not been restored severely or treated endodontically, and to compare the thickness of the remaining tooth structure from the center of the canal to the outer surface of the deepest groove area in C-shaped mandibular second molar to that of "danger zone of perforation" in normal mandibular second molar. This distance was measured at the cervical, middle, and apical third level each. From 220 teeth, C-shaped canals were found in 98 teeth (44.5%). Almost all the grooves were directed lingual (99%). The continuous C-shaped canal was the most frequently found (49%) and the separated canal was the least (17.4%). The thinnest remaining tooth structure in the groove area of the C-shaped mandibular second molar was not different from that of the danger zone of normal mandibular second molar at the three levels (p > 0.05). PMID:16410060

Jin, Guang-Chun; Lee, Seong-Jong; Roh, Byoung-Duck



Mandibular cephalometric characteristics of a Saudi sample of patients having impacted third molars  

PubMed Central

Objective To evaluate the cephalometric characteristics of mandibles of Saudi patients having impacted third molars and to compare them to those of patients having normally erupted third molars. Material and methods One hundred and twenty-one Saudi adult subjects (59 females and 62 males; age: 20–40 years) were divided into two groups based on the status of the mandibular third molars: (1) impaction group and (2) normal group. Means and standard deviations of 21 cephalometric measurements related to mandibular geometry were measured and compared between the two groups using the unpaired t-test. Males and females in the impaction group were also compared with their equivalent subgroups in the normal group using the unpaired t-test. Results Anteroposteriorly, space distal to second molar, ramal width and mandibular body length were significantly less in the impaction group than in the control group. In addition, posterior teeth were more upright in the impaction group. Vertically, posterior alveolar height was significantly less in the impaction group. The Y-axis was significantly increased in the impaction group. The significance of these measurements was variable between males and females. Conclusions Third-molar impactions in the Saudis living in the Western region of Saudi Arabia were more likely to occur when inadequate retromolar space is present. This can be attributed to certain mandibular skeletal and dental features, among which the increased width of mandibular ramus and backward inclination of posterior teeth seem to be the most influencing factors in both sexes.

Hassan, Ali H.



Reconstruction of human mandibular continuity defects with allogenic scaffold and autologous marrow mesenchymal stem cells.  


Mandibular continuity defects occur after tumor resection, maxillofacial injury, or osteomyelitis. In this clinical pilot study, we report a novel method for reconstruction of mandibular continuity defect by in vivo tissue engineering. In 3 patients with critical-size mandibular bone defects, the allogenic mandibular bone scaffold was customized, loaded by ex vivo expanded mesenchymal stem cells, and transplanted into the surgical defect site. According to the bone scintigraphy, vascularized bone was identified in 2 cases. In spiral computed tomography, normal bone healing without significant bone resorption was seen at the 2 viable grafts, but at the failed construction, there was a lack of osteointegration to the adjacent host bone and a higher density in the medullary bone. According to the serial panoramic imaging, the patients with viable bone grafts had normal bone healing, whereas the other patient had progressive overall bone resorption. Our results demonstrate the feasibility of allogenic bone scaffold loaded by mesenchymal stem cells in the reconstruction of mandibular continuity defects. Although long-term results are not yet available, it may be a novel method of reconstruction and a basis for further studies. PMID:23851791

Zamiri, Barbad; Shahidi, Shoaleh; Eslaminejad, Mohamadreza Baghaban; Khoshzaban, Ahad; Gholami, Mehdi; Bahramnejad, Emad; Moghadasali, Reza; Mardpour, Soura; Aghdami, Nasser



The root and root canal morphology of the human mandibular second premolar: a literature review.  


The objective was to review thoroughly the literature of the root and root canal morphology of the human mandibular second premolar and compare the results with the mandibular first premolar. Published studies cite the anatomy and morphology of the mandibular second premolar tooth for more than 7700 teeth. These studies were divided into anatomic studies reporting the number of roots, number of canals, and apical anatomy. Differences caused by gender and ethnicity have also been reported. Individual case reports of anomalies were included to demonstrate the extreme range of variation. Almost all of the teeth in the anatomic studies were single-rooted (99.6%). The incidence of 2 roots (0.3%) and 3 roots (0.1%) was extremely rare. Anatomic studies of the internal canal morphology found that a single canal was present in 91.0% of the teeth. A single apical foramen was found in 91.8% of the teeth. The incidence of more than 1 root (0.4%), more than 1 canal system (9.9%), and more than 1 foramen (8.2%) is lower than that of the mandibular first premolar tooth (2.0%, 24.2%, and 21.1%, respectively). However, the root and root canal morphology of the mandibular second premolar can be extremely complex and requires careful assessment. PMID:17931927

Cleghorn, Blaine M; Christie, William H; Dong, Cecilia C S



Selfprotective smart orthopedic implants.  


In this review, we discuss current advances leading to an exciting change in implant design for orthopedic surgery. The initial biomaterial approaches in implant design are being replaced by cellular-molecular interactions and nanoscale chemistry. New designs address implant complications, particularly loosening and infection. For infection, local delivery systems are an important first step in the process. Selfprotective 'smart' devices are an example of the next generation of orthopedic implants. If proven to be effective, antibiotics or other active molecules that are tethered to the implant surface through a permanent covalent bond and tethering of antibiotics or other biofactors are likely to transform the practice of orthopedic surgery and other medical specialties. This new technology has the potential to eliminate periprosthetic infection, a major and growing problem in orthopedic practice. PMID:17187471

Parvizi, Javad; Antoci, Valentin; Hickok, Noreen J; Shapiro, Irving M



Influence of the implant diameter with different sizes of hexagon: analysis by 3-dimensional finite element method.  


The aim of this study was to evaluate the stress distribution in implants of regular platforms and of wide diameter with different sizes of hexagon by the 3-dimensional finite element method. We used simulated 3-dimensional models with the aid of Solidworks 2006 and Rhinoceros 4.0 software for the design of the implant and abutment and the InVesalius software for the design of the bone. Each model represented a block of bone from the mandibular molar region with an implant 10 mm in length and different diameters. Model A was an implant 3.75 mm/regular hexagon, model B was an implant 5.00 mm/regular hexagon, and model C was an implant 5.00 mm/expanded hexagon. A load of 200 N was applied in the axial, lateral, and oblique directions. At implant, applying the load (axial, lateral, and oblique), the 3 models presented stress concentration at the threads in the cervical and middle regions, and the stress was higher for model A. At the abutment, models A and B showed a similar stress distribution, concentrated at the cervical and middle third; model C showed the highest stresses. On the cortical bone, the stress was concentrated at the cervical region for the 3 models and was higher for model A. In the trabecular bone, the stresses were less intense and concentrated around the implant body, and were more intense for model A. Among the models of wide diameter (models B and C), model B (implant 5.00 mm/regular hexagon) was more favorable with regard to distribution of stresses. Model A (implant 3.75 mm/regular hexagon) showed the largest areas and the most intense stress, and model B (implant 5.00 mm/regular hexagon) showed a more favorable stress distribution. The highest stresses were observed in the application of lateral load. PMID:21463183

Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; de Moraes, Sandra Lúcia Dantas; Falcón-Antenucci, Rosse Mary; de Carvalho, Paulo Sérgio Perri; Noritomi, Pedro Yoshito



Long-Term Evaluation of Immediately Loaded Implants in the Edentulous Mandible Using Fixed Bridges and Platform Shifting.  


BACKGROUND: The immediate loading concept has been extensively documented in the anterior part of the mandible when six primary stable implants are placed, splinted with a fixed prosthesis. PURPOSE: The aim of this study was to evaluate the long-term success of immediately occlusal loaded implants with a progressive thread design and platform shifting in the edentulous mandible. MATERIALS AND METHODS: Seventy-eight implants placed in 13 patients and were connected with their abutments immediately after surgery. The implants were splinted using a fixed temporary restoration having occlusal contacts in the centric and group function in the lateral movements of the mandible (immediate occlusal loading). The patients were advised to use soft/liquid diet for the first 6 to 8 weeks of healing in order to reduce excessive loading in the bone-to-implant interface. Abutment level impressions were taken without removing the abutments in order to fabricate the final prostheses. The final restorations were delivered 4 to 8 weeks after surgery and cemented temporarily in order to evaluate the peri-implant soft tissue condition at the different time intervals after removal of the restoration. Clinical stability and radiological indices were evaluated at the start of loading, at 3-month interval after loading, and then annually. RESULTS: After a mean loading period of 75.29 (±?38.18) months, no implant was lost (100% success rate). All clinical indices had values in normal levels. The Periotest values demonstrated a continuous reduction, representing high stability. The crestal bone level was relatively stable and only minimal crestal bone loss was observed in some implants. CONCLUSIONS: Long-term success and stability of the peri-implant tissues around immediately loaded mandibular implants are expected when implants with platform shifting are restored with bridges without abutment removal. PMID:23305406

Romanos, Georgios E; Gaertner, Kathrin; Nentwig, Georg H



Uncommon mandibular osteomyelitis in a cat caused by Nocardia africana  

PubMed Central

Background Nocardiosis is an unusual infection in companion animals characterized by suppurative to pyogranulomatous lesions, localized or disseminated. Cutaneous-subcutaneous, pulmonary and systemic signs are observed in feline nocardiosis. However, osteomyelitis is a rare clinical manifestation in cats. Nocardia cyriacigeorgica (formerly N. asteroides sensu stricto), Nocardia brasiliensis, Nocardia otitidiscaviarum, and Nocardia nova are the most common pathogenic species identified in cats, based on recent molecular classification (16S rRNA gene). The present report is, to our knowledge, the first case of mandibular osteomyelitis in a cat caused by Nocardia africana, diagnosed based upon a combination of methods, including molecular techniques. Case presentation A one-year-old non-neutered female cat, raised in a rural area, was admitted to the Companion Animal Hospital-PUCPR, São José dos Pinhais, State of Paraná, Brazil, with a history a progressive facial lesion, difficulty apprehending food, loss of appetite, apathy and emaciation. Clinical examination showed fever, submandibular lymphadenitis, and a painless, 8 cm diameter mass, which was irregularly-shaped, of firm consistency, and located in the region of the left mandible. The skin around the lesion was friable, with diffuse inflammation (cellulitis), multiple draining sinuses, and exudation of serosanguinous material containing whitish “sulfur” granules. Diagnosis was based initially in clinical signs, microbiological culture, cytological, and histopathological findings, and radiographic images. Molecular sequencing of 16S rRNA of isolate allowed diagnosis of Nocardia africana. Despite supportive care and antimicrobial therapy based on in vitro susceptibility testing the animal died. Conclusion The present report describes a rare clinical case of feline osteomyelitis caused by Nocardia africana, diagnosed based upon a combination of clinical signs, microbiological culture, cytological and histopathological findings, radiographic images, and molecular methods. The use of modern molecular techniques constitutes a quick and reliable method for Nocardia species identification, and may contribute to identification to new species of Nocardia that are virulent in cats.



Root canal anatomy of mandibular second molars. Part I.  


The root canal anatomy of 149 mandibular second molars was studied using a technique in which the pulp was removed, the canal space filled with black ink and the roots demineralized and made transparent. Of the 149 teeth, 22 per cent had single roots, 76 per cent had two roots and 2 per cent had three roots. In the single-rooted teeth, three canals were most common, while in the mesial root of the two-rooted teeth, two canals that joined near the apex and one canal in the distal root were most frequent. Round canals were most common in two-rooted teeth and C-shaped canals in single-rooted teeth. Transverse anastomoses were found in 33 per cent of roots, most commonly in the middle third of the root. Lateral canals were found in 72 per cent of roots, most commonly in the apical third of the root. The apical foramen was positioned at the apex in only 33 per cent of roots, and apical deltas were found in 35 per cent. The patient's age and race affected canal shape, with more round canals present in patients over 35 years of age, and more C-shaped canals in Asians. The sex of the patient and the side of the mouth affected the presence of apical deltas, with more being found in males and on the left side. Single-rooted teeth had more complex root canal systems than two-rooted teeth, with more lateral canals, transverse anastomoses, apical deltas and C-shaped canals. PMID:2391179

Manning, S A



Chloride channels regulate chondrogenesis in chicken mandibular mesenchymal cells.  


Voltage gated chloride channels (ClCs) play an important role in the regulation of intracellular pH and cell volume homeostasis. Mutations of these genes result in genetic diseases with abnormal bone deformation and body size, indicating that ClCs may have a role in chondrogenesis. In the present study, we isolated chicken mandibular mesenchymal cells (CMMC) from Hamburg-Hamilton (HH) stage 26 chick embryos and induced chondrocyte maturation by using ascorbic acid and ?-glycerophosphate (AA-BGP). We also determined the effect of the chloride channel inhibitor NPPB [5-nitro-2-(3-phenylpropylamino) benzoic acid] on regulation of growth, differentiation, and gene expression in these cells using MTT and real-time PCR assays. We found that CLCN1 and CLCN3-7 mRNA were expressed in CMMC and NPPB reduced expression of CLCN3, CLCN5, and CLCN7 mRNA in these cells. At the same time, NPPB inhibited the growth of the CMMC, but had no effect on the mRNA level of cyclin D1 and cyclin E (P>0.05) with/without AA-BGP treatment. AA-BGP increased markers for early chondrocyte differentiation including type II collagen, aggrecan (P<0.01) and Sox9 (P<0.05), whilst had no effect on the late chondrocyte differentiation marker type X collagen. NPPB antagonized AA-BGP-induced expression of type II collagen and aggrecan (P<0.05). Furthermore, NPPB downregulated type X collagen (P<0.05) with/without AA-BGP treatment. We conclude that abundant chloride channel genes in CMMC play important roles in regulating chondrocyte proliferation and differentiation. Type X collagen might function as a target of chloride channel inhibitors during the differentiation process. PMID:20832772

Tian, Meiyu; Duan, Yinzhong; Duan, Xiaohong



Magnetic resonance imaging findings and clinical symptoms in the temporomandibular joint in patients with mandibular continuity defects  

Microsoft Academic Search

Purpose: This study explored the morphologic changes and clinical symptoms related to the temporomandibular joint (TMJ) associated with long-term lack of mandibular continuity.Patients and Methods: The subjects were 20 patients (40 TMJs) who underwent mandibulectomy including the condyle or segmental mandibulectomy without mandibular reconstruction more than 6 months previous to the study. The 40 TMJs were classified into the following

Yoshiki Hamada; Toshirou Kondoh; Kazutoshi Nakaoka; Kanichi Seto



Shape of the Lateral Mandibular Outline in Lemuridae: A Quantitative Analysis of Variability Using Elliptical Fourier Analysis  

Microsoft Academic Search

While several morphometric analyses in lemurids have focused on the craniofacial complex, the characterization of their mandibular morphology has received less attention. The mandibular outline, in lateral perspective, was quantified using elliptical Fourier analysis, in an osteological sample encompassing 189 lemurid mandibles (66 Eulemur, 51 Hapalemur, 22 Lemur and 50 Varecia), and compared using multivariate statistical techniques. The taxonomic value

Herimalala Raveloson; Yves Rumpler; Matthieu Schmittbuhl



Restoration of mechanical strength and morphological features of the periodontal ligament following orthodontic retention in the rat mandibular first molar  

Microsoft Academic Search

SUMMARY Biomechanical properties and morphological features of the periodontal ligament (PDL) in the rat mandibular molars were examined during orthodontic retention. Seventy-three male rats of the Wistar strain, 8 weeks of age, were used for biomechanical analysis and six rats for morphological analysis. An elastic band was inserted between the mandibular first and second molars for 4 days; after removal

Tadayoshi Fukui; Akira Yamane; Koichiro Komatsu; Mototsugu Chiba


Cone-beam computed tomography study of root and canal morphology of mandibular premolars in a western Chinese population  

PubMed Central

Background Traditional radiography is limited in its ability to give reliable information on the number and morphology of root canals. The application of cone-beam computed tomography (CBCT) provides a non-invasive three-dimensional confirmatory diagnosis as a complement to conventional radiography. The aim of this study was to evaluate the root and canal morphology of mandibular premolars in a western Chinese population using CBCT scanning. Methods The sample included 149 CBCT images comprising 178 mandibular first premolars and 178 second premolars. The tooth position, number of roots and canals, and canal configuration according to Vertucci’s classification were recorded. Results The results showed that 98% of mandibular first premolars had one root and 2% had two roots; 87.1% had one canal, 11.2% had two canals and 0.6% had three canals. The prevalence of C-shaped canals was 1.1%. All mandibular second premolars had one root; 97.2% had one canal and 2.2% had two canals. The prevalence of C-shaped canals was 0.6%. Conclusions The prevalence of multiple canals in mandibular first premolars was mainly of Type V, and mandibular second premolars had a low rate of canal variation in this western Chinese population. Root canal bifurcation occurred at the middle or apical third in most bicanal mandibular premolars. CBCT scanning can be used in the management of mandibular premolars with complex canal morphology.



Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet.  


The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies. Am J Phys Anthropol 152:383-392, 2013. © 2013 Wiley Periodicals, Inc. PMID:24104725

Mays, Simon A



Suppression of queen rearing in European and Africanized honey bees Apis mellifera L. by synthetic queen mandibular gland pheromone  

Microsoft Academic Search

Summary Queen rearing is suppressed in honey bees (Apis mellifera L.) by pheromones, particularly the queen's mandibular gland pheromone. In this study we compared this pheromonally-based inhibition between temperate and tropically-evolved honey bees. Colonies of European and Africanized bees were exposed to synthetic queen mandibular gland pheromone (QMP) for ten days following removal of resident queens, and their queen rearing

J. S. Pettis; M. L. Winston; A. M. Collins



Correction of mandibular deficiency by inverted-L osteotomy of ramus and iliac crest bone grafting  

PubMed Central

This study was to describe the use of inverted-L osteotomy of ramus and iliac bone graft for the management of mandibular deficiency in adult patients. From 2008 to 2010, 11 patients (aged 19 to 29 years) with mandibular deficiency underwent intraoral or extraoral inverted-L osteotomy of ramus and iliac crest bone grafting. Data were collected from the patients' records, photographs and radiographs. The height and width of the ramus were successfully expanded by inverted-L osteotomy and iliac crest bone grafting with minimal complications in all patients, resulting in significant improvement in occlusion and facial appearance. Our early results showed that the inverted-L osteotomy of ramus and iliac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular deficiency.

Zhu, Song-Song; Feng, Ge; Li, Ji-Hua; Luo, En; Hu, Jing



Radix Entomolaris in Mandibular First Molars in Indian Population: A Review and Case Reports  

PubMed Central

Purpose. The aim of this paper is to present cases of mandibular first molars with an additional distolingual root and their management using appropriate instruments and techniques. Basic Procedures and Main Findings. Mandibular molars can sometimes present a variation called radix entomolaris, wherein the tooth has an extra root attached to its lingual aspect. This additional root may complicate the endodontic management of the tooth if it is misdiagnosed or maltreated. This paper reviews the prevalence of such cases in Indian population and reports the management of 6 such teeth. Principal Conclusions. (1) It is crucial to be familiar with variations in tooth/canal anatomy and characteristic features since such knowledge can aid location and negotiation of canals, as well as their subsequent management. (2) Accurate diagnosis and careful application of clinical endodontic skill can favorably alter the prognosis of mandibular molars with this root morphology.

Attam, Kanika; Nawal, Ruchika Roongta; Utneja, Shivani; Talwar, Sangeeta



Abnormal mandibular growth after craniovertebral surgery in Morquio syndrome type A.  


Morquio syndrome or MPS4A is an autosomal recessive inherited metabolic disease, due to a deficiency of N-acetil-galactosamine-6-sulfatase (OMIM 253000). Hypoplastic odontoid processes causing atlantoaxial subluxation and cervical myelopathy are usual clinical findings. Surgical intervention of craniocervical fusion is often performed to prevent this complication. Clinical and cephalometric findings in a patient affected by Morquio syndrome after craniovertebral surgery are described. Facial growth pattern in the lateral plane changed dramatically. The mandibular gonial angle (ArGoMe), the body of the mandible (GoGn), and the total length of the mandible (CoGn) increased abnormally, whereas the mandibular ramus (CoGo) exhibited normal growth. Knowledge of the possibility of abnormal mandibular growth may contribute in long-term orthodontic management of such subjects. PMID:15898389

Defraia, Efisio; Marinelli, Andrea; Antonini, Antonino; Giuntini, Veronica



Changes in the radiographic characteristics of the mandibular alveolar process in dentate women with varying bone mineral density: A 5-year prospective study  

Microsoft Academic Search

The association between skeletal bone mineral density (BMD) and mandibular alveolar bone mass has been reported to be rather weak, probably due to local functional factors. Many new investigations are therefore focused on assessing the mandibular bone structure. No long-term structural alterations have been reported in human mandibular bone with the exception of alveolar crest changes related to periodontal disease.

Grethe Jonasson; Lisa Jonasson; Stavros Kiliaridis



Corticosteroid intravitreal implants.  


Intraocular implants developed for ocular inflammation which release glucocorticoids for a prolonged period within the vitreous cavity make use of either a bioerodible polymer (dexamethasone in polylactic acid-coglycolic acid matrix) or non-erodible implantable device (fluocinolone acetonide, FA, in a polyvinyl acetate/silicone laminate). Pharmacologically, both steroids are similar in their binding characteristics to glucocorticoid receptors (GR), their ability to transactivate the GR complex and their vitreous half-lives. They both possess neuroprotective properties for retina and retinal pigment epithelium which place them apart from triamcinolone acetonide. Triamcinolone acetonide's higher lipophilicity makes it possible to create an implant with prolonged release characteristics, but may be increasing the propensity for ocular side effects such as cataract and glaucoma. In clinical trials, both implants were shown to be effective at inhibiting intraocular inflammation in patients with intermediate or posterior uveitis. The Dexamethasone implant is inserted through a 22-gauge needle through the pars plana and can control inflammation for up to 6 months. The FA implant requires surgical insertion through the pars plana and can control inflammation for up to 3 years. The MUST trial has shown the FA implant when placed bilaterally to be slightly more effective than strict systemic therapy, though at the cost of additional ocular surgeries for cataract and glaucoma. Certain clinical situations particularly with asymmetric uveitis may in fact favor local vs. systemic therapy. PMID:22517210

de Smet, Marc D



Risk Factors and Dose-Effect Relationship for Mandibular Osteoradionecrosis in Oral and Oropharyngeal Cancer Patients  

SciTech Connect

Purpose: To analyze risk factors and the dose-effect relationship for osteoradionecrosis (ORN) of the mandible after radiotherapy of oral and oropharyngeal cancers. Materials and Methods: One-hundred ninety-eight patients with oral (45%) and oropharyngeal cancer (55%) who had received external radiotherapy between 1990 and 2000 were retrospectively reviewed. All patients had a dental evaluation before radiotherapy. The median radiation dose was 60 Gy (range, 16-75 Gy), and the median biologically effective dose for late effects (BED{sub late}) in bone was 114 Gy{sub 2} (range, 30-167 Gy{sub 2}). Results: The frequency of ORN was 13 patients (6.6%). Among patients with mandibular surgery, eight had ORN at the surgical site. Among patients without mandibular surgery, five patients had ORN on the molar area of the mandible. The median time to ORN was 22 months (range, 1-69 months). Univariate analysis revealed that mandibular surgery and Co-60 were significant risk factors for ORN (p = 0.01 and 0.04, respectively). In multivariate analysis, mandibular surgery was the most important factor (p = 0.001). High radiation doses over BED 102.6 Gy{sub 2} (conventional dose of 54 Gy at 1.8 Gy/fraction) were also a significant factor for ORN (p = 0.008) and showed a positive dose-effect relationship in logistic regression (p = 0.04) for patients who had undergone mandibular surgery. Conclusions: Mandibular surgery was the most significant risk factor for ORN of mandible in oral and oropharyngeal cancers patients. A BED of 102.6 Gy{sub 2} or higher to the mandible also significantly increases the risk of ORN.

Lee, Ik Jae; Koom, Woong Sub [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Chang Geol, E-mail: cglee1023@yuhs.a [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Yong Bae; Yoo, Sei Whan; Keum, Ki Chang; Kim, Gwi Eon [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Eun Chang [Department of Otolaryngology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cha, In Ho [Department of Oral and Maxillofacial Surgery, Yonsei University College of Dentistry, Seoul (Korea, Republic of)



Endoprosthetic reconstructive surgery with medical grade long term implantable silicone in facial asymmetry.  


The authors present their experience over a period of 13 years (1998-2011) regarding a cohort of 54 patients. In an extensive loss of tissues resulted from congenital malformations (maxillary and mandibular malformations, micro stoma), collagenosis (scleroderma, Romberg Syndrome), traffic and work accidents, post surgical (cancer and facial nerve paralyze), when usual surgical procedures fail to establish the normal look of the patient medical grade long-term implantable silicone endoprosthetic reconstruction (rehabilitation) intervenes. Using a specific technique and materials like long-term implantable silicone grade, the resulted endoprostheses replace and create the aesthetic and a normal anatomy of the specified region, very well tolerated, elastic and non-allergic and with a perfect acceptation from the body all the life. PMID:23346254

L??can, E; Popescu, C R



Non-syndromic occurrence of true generalized microdontia with mandibular mesiodens - a rare case  

PubMed Central

Abnormalities in size of teeth and number of teeth are occasionally recorded in clinical cases. True generalized microdontia is rare case in which all the teeth are smaller than normal. Mesiodens is commonly located in maxilary central incisor region and uncommon in the mandible. In the present case a 12 year-old boy was healthy; normal in appearance and the medical history was noncontributory. The patient was examined and found to have permanent teeth that were smaller than those of the average adult teeth. The true generalized microdontia was accompanied by mandibular mesiodens. This is a unique case report of non-syndromic association of mandibular hyperdontia with true generalized microdontia.



Changes in mandibular cortical width measurements with age in men and women  

Microsoft Academic Search

Summary  Automated software was used to measure the mandibular cortical width in a large sample of dental radiographs. We determined\\u000a that cortical thinning normally starts in women at age 42.5 years and accelerates thereafter. We can estimate population referral\\u000a rates and thus enable cost benefit analyses for osteoporosis detection by dentists.\\u000a \\u000a \\u000a \\u000a \\u000a Introduction  Previous studies have shown that the mandibular cortical width is significantly

M. Roberts; J. Yuan; J. Graham; R. Jacobs; H. Devlin



Autogenous mandibular symphysis graft for orbital floor reconstruction: a preliminary study  

Microsoft Academic Search

Objective  The present study aimed to evaluate and analyze postoperative results of Autogenous Mandibular Symphysis graft material for\\u000a orbital floor reconstruction.\\u000a \\u000a \\u000a \\u000a Material and methods  A retrospective study was conducted on 11 patients, having an isolated blow out fracture (n=4) or orbital floor defects associated\\u000a with other fractures (n=7). These fractures were reconstructed with Mandibular symphysis bone grafts. The Grafts were used\\u000a where

B. M. Rudagi; Rajshekhar Halli; Uma Mahindra; Viraj Kharkar; Harish Saluja



[The para-clinic investigation of temporo-mandibular joint changes in patients with acromegaly].  


The Acromegaly is an endocrinological disease determined by the hypersecretion of STH in a certain period of the body evolution and it causes the hypertrophy of bones in general and of mandible and cranio-facial bones, determining a disorder due to this development of bones, associated with troubles in the activity of muscles and of the phospho-calcium metabolism. This study was made on a group of 33 acromegaly patients. Their temporo-mandibular joint was investigated by ortopantomography, tomography, computer tomography and scintigraphy. All of these exams shows the changes in temporo-mandibular joint due to the cells hyperactivity determined by the hypersecretion of STH. PMID:12092142

Mor?ra?u, C; Burlui, V; Olaru, C; Boza, C; Bort?, C; Mor?ra?u, G; Brînz?, M


Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo  

PubMed Central

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo(including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group ‘distinctness values’) was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of ‘distinctness values’ was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of ‘distinctness values’ test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the fossil specimens (i.e. H. sapiens, H. heidelbergensis, Asian H. erectus and a combined ‘African Homo’ group consisting of H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster and late African H. erectus). These four groups appear to be distinct at a level similar to, or greater than, that of modern hominid species. In addition, the mandibular corpora of H. neanderthalensis could be distinguished from those of ‘African Homo’, although not from those of H. sapiens, H. heidelbergensis, or the Asian H. erectus group. The results suggest that the features most commonly preserved on the hominin mandibular corpus have some taxonomic utility, although they are unlikely to be useful in generating a reliable alpha taxonomy for early African members of the genus Homo.

Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A



A rare case of transmigration of mandibular canine associated with an odontoma.  


Transmigration or intraosseous migration of mandibular canine is a very rare phenomenon. Specific aetiology and mechanism of transmigration is still unclear. Majority of these transmigrated canines are impacted, asymptomatic and involve the left mandible. This article describes a rare case of transmigrated mandibular right permanent canine associated with a retained deciduous right canine and an odontoma in a 25-year-old man with a follow-up of 3 years. The present case report also highlights the importance of early diagnosis and periodic monitoring of impacted teeth with panoramic radiography to avoid the occurrence of any associated pathologies and further allow interceptive treatment for possible better results. PMID:23814002

Madiraju, G S; Rao, Kolasani Srinivasa; Singamaneni, Vijaykumar



Immediate reconstruction of mandibular defects with a composite sternocleidomastoid musculoclavicular graft  

SciTech Connect

The problem of mandibular reconstruction has been approached using many surgical techniques. This article studies one such approach--reconstruction using full-thickness clavicle pedicled on the sternocleidomastoid muscle. Five patients with stage II and stage III carcinoma of the anterior part of the floor of the mouth were treated with mandibular resection and neck dissection. The resulting defects were immediately reconstructed with the clavicle-sternocleidomastoid muscle technique. The patients were observed from one to three years and were examined postoperatively with technetium Tc 99m medronate scans, which demonstrated the grafts to be viable. The technique proved reliable in a limited clinical trial.

Barnes, D.R.; Ossoff, R.H.; Pecaro, B.; Sisson, G.A.



The Mandibular First Molar with Three Canals in the Mesial Root- A Case Report  

PubMed Central

The dynamic concept of the root canal system, which describes a variable morphology of the multiple root canals which are inter-connected by anastomoses, has been established as the prevailing state in the mandibular molars. The aim of this case report was to describe the unusual root canal anatomy that was detected in the mandibular first molar during the routine endodontic treatment. The clinical and the radiographic examinations allowed the detection of the middle mesial root canal between the mesiobuccal and the mesiolingual root canals. This report highlights the importance of such examinations and the need to find and treat the additional canals, to achieve a successful endodontic treatment.

Deepalakshmi, Mohanavelu; Anupama, Ramachandran; Khan, Hidayathulla Sulthan Ibrahim Raja; Kumar, Kumarappan Senthil



Mandibular cystic defect: A composite approach with rhBMP-2 and rib graft  

Microsoft Academic Search

Objective  To report treatment of severe mandibular defect caused by Aneurysmal Bone Cyst (ABC) in a 6-year-old child, with off-label\\u000a use of Recombinant Bone Morphogenetic Protein-2 (rhBMP-2)\\u000a \\u000a \\u000a \\u000a Study Design  Clinical Study.\\u000a \\u000a \\u000a \\u000a Method  After corrective segmental mandibulectomy, mandible was stabilized by precontoured titanium reconstruction plates spanning\\u000a the entire defect. After confirming final diagnosis and a wait and watch approach, rhBMP-2 was inserted into mandibular

S. M. Balaji



Changes in the Masseter Muscle After Curved Osteotomy of the Prominent Mandibular Angle  

Microsoft Academic Search

Background  This study aimed to explore the changes in the masseter muscle after curved osteotomy of the prominent mandibular angle and\\u000a to supply guidance for resection of the mandibular angle.\\u000a \\u000a \\u000a \\u000a Methods  Ultrasonography was used to assess changes in the thickness of the masseter muscle after curved osteotomy for 10 patients\\u000a (20 hemimandibles) at the 6-month following-up assessment. The measurements were performed under

Min Li; Lai Gui; Jian Feng Liu; Xin Lin



Severe open bite due to traumatic condylar fractures treated nonsurgically with implanted miniscrew anchorage.  


This case report illustrates the use of miniscrews to treat a patient with an open bite caused by mandibular condylar fractures. The patient was 36 years old when she visited our hospital with a chief complaint of difficulty with chewing. She had suffered condylar and maxillary bone fractures in a traffic accident 6 months before her visit. She had an anterior open bite and Angle Class II molar relationships. Her mandibular midline was deviated to the right relative to the maxilla. The cephalometric analysis showed a skeletal Class II relationship. Titanium miniscrews were implanted in the bilateral maxillary buccal areas. The maxillary dentition was retracted and intruded by using elastomeric chains and miniscrews. After this treatment, an Angle Class I molar relationship was achieved, her overjet and overbite became ideal, and a good facial appearance was obtained. The total active orthodontic treatment period was 33 months. Treating an open bite with molar intrusion often leads to counterclockwise rotation of the mandible; however, in this patient, the mandible was moved anteriorly and upward. We believe that this movement was caused by the patient's condylar fractures and the subsequent remodeling. Although there was some relapse, our results suggest that implant anchorage is useful for correcting anterior open bites originating from condylar fractures. PMID:23540631

Yanagita, Takeshi; Adachi, Rie; Kamioka, Hiroshi; Yanashiro, Takashi



Biolink Implantable Telemetry System.  

National Technical Information Service (NTIS)

Most biotelemetry applications deal with the moderated data rates of biological signals. Few people have studied the problem of transcutaneous data transmission at the rates required by NASA's Life Sciences-Advanced BioTelemetry System (LS-ABTS). Implante...

R. J. Betancourt-Zamora



[Implantation metastasizing of craniopharyngioma].  


The paper describes two cases of implantation metastasizing of craniopharyngioma after its resection using combined (transcallosal and subfrontal) and pterional approach. The mechanisms of metastasizing and possible ways of prevention are discussed. PMID:23379184

Zhukov, V Iu; Konovalov, A N; Pitsehelauri, D I; Gorelyshev, S K; Kadyrov, Sh U; Krasnova, T S; Mazerkina, N A



Implantable Insulin Delivery System.  

National Technical Information Service (NTIS)

An insulin delivery system suitable for experimental implants and external use has been developed to study glucose control for diabetics. The programmable system developed at Sandia National Laboratories, in conjunction with the University of New Mexico S...

J. T. Love J. I. Gaona



Urinary incontinence - injectable implant  


Intrinsic sphincter deficiency repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... inject material into the tissue next to the sphincter. The implant procedure is usually done in the ...


Periodontal repair in dogs: effect of allogenic freeze-dried demineralized bone matrix implants on alveolar bone and cementum regeneration.  


The objective of this study was to evaluate alveolar bone and cementum regeneration following surgical placement of an allogenic, freeze-dried, demineralized bone matrix (DBM) cortical strip implant. Critical size, supraalveolar periodontal defects were surgically created around the second, third, and fourth mandibular premolar teeth in eight mongrel dogs. Contralateral jaw quadrants in six animals were randomly assigned to receive the DBM implant, or serve as surgical control. Two additional animals received bilateral DBM implants. Flaps were coronally advanced to submerge teeth and implants, and sutured. Three animals were exited from the study due to extensive early wound failure. Remaining animals were sacrificed at 8 weeks postsurgery. Histometric recordings included defect height, bone regeneration/DBM implant height, cementum regeneration height, root resorption, and ankylosis. Large areas of unresorbed DBM exhibiting fragmentation and empty osteocyte lacunae were observed adjacent to new bone formation, or bone formation was observed adjacent to or within the implant, often exhibiting ankylosis. Cementum regeneration appeared enhanced in shelter of the DBM implant. Histometric recordings (mean+/-SD) for DBM and control defects, respectively, were: defect height, 4.8+/-0.2 mm and 4.4+/-0.2 mm; bone regeneration/DBM implant height, 4.0+/-1.3 mm and 1.2+/-0.6 mm; cementum regeneration height, 1.4+/-0.4 mm and 0.7+/-0.2 mm; root resorption, 0.5+/-0.3 mm and 1.2+/-0.3 mm; and ankylosis, 0.5+/-0.2 mm and 0.1+/-0.1 mm without statistically significant differences between experimental conditions (N=3). Within the limitations of this study, the histologic observations suggest that surgical implantation of allogenic, freeze-dried DBM cortical strip implants may have a potential to support cementum regeneration, possibly by providing conditions for guided tissue regeneration, however, alveolar regeneration appears unpredictable. PMID:9527558

Kim, C K; Cho, K S; Choi, S H; Prewett, A; Wikesjö, U M



Anatomic position of the lingual nerve in the mandibular third molar region with special consideration of an atrophied mandibular crest: an anatomical study  

Microsoft Academic Search

Abstract.The position of the lingual nerve in the mandibular third molar region was measured and documented in 68 cadaver dissections (34 adult cadaver heads). In 8.8% of the dissections, the lingual nerve was found at or above the level of the alveolar crest. In the horizontal plane, the nerve contacted the lingual plate of the third molar in 57.4% of

F. W. Hölzle; K.-D. Wolff



Ion implant round robin  

NASA Astrophysics Data System (ADS)

The Silicon Valley Implant Users Group (SVIUG) ran a round robin to compare the uniformity and accuracy of various tools in active use in the Valley. Results are presented for several As doses at 80 keV. Results are also presented for a sheet resistance round robin involving the five Rs mappers used to characterize the ion implant (I/I) round robin wafers. Prometrix Corp., Santa Clara, CA 95051, USA.

Current, M. I.; Keenan, W. A.



An implantable artificial pancreas  

Microsoft Academic Search

The artificial implantable pancreas is seen as the optimal means of therapy in patients with severe diabetes mellitus. The\\u000a implantable pancreas consists of three modules; (i) the dosing unit, (ii) the control circuit and (iii) a glucose sensor for\\u000a the realisation of a feedback system. Intensive research has been devoted to essential items, such as a dosing valve with\\u000a only

W. Schubert; P. Baurschmidt; J. Nagel; R. Thull; M. Schaldach



Ion implant standard  

NASA Astrophysics Data System (ADS)

The Greater Silicon Valley Implant Users Group (GSVIUG) has been working with the American Society for Testing Materials (ASTM) and the National Institute of Standards and Technology (NIST, previously known as NBS) to develop a standard for ion implantation. This standard would address two critical needs of the industry: (1) standard reference material (SRM) for certifying and calibrating equipment, and (2) a recommended standard procedure for fabricating such a standard. The SRM would be a wafer that had been implanted with a specified species, energy and dose. Its average sheet resistance and uniformity would be certified to be within certain tolerances. It would be used to verify the performance of the four-point probe and sheet resistance mapping equipment and to calibrate analytical characterization techniques such as secondary ion mass spectroscopy (SIMS), Rutherford backscattering spectroscopy (RBS) and spreading resistance profiling (SRP). An unannealed sample could be used to calibrate Thermawave, ellipsometer and other optical tools and to verify annealing systems. The standard procedure would prescribe the recommended steps to produce the same wafer in the fab. This would help determine if an implanter is operating correctly at the specified conditions. We have reviewed all the previous implant round robins and studies and solicited input from implant vendors and implant service organizations in recommending a set of implant conditions for a proposed standard. Particular attention was paid to the requirement of stability over time and minimum variation with ambient temperature. Fabrication specifications for species, energy and dose are detailed. Plots are also presented for the sensitivity to various parameters that could influence the results, such as substrate resistivity, screen oxide thickness, anneal time and temperature and measurement conditions.

Larson, L. A.; Keenan, W. A.; Johnson, W. H.



Pedicled Lingual flap to provide keratinized tissue regeneration over dental implants: A description of the technique and a case report.  


Abstract Aim of this study is to report the efficacy of a lingual pedicle flap for soft tissue pre-prosthetic surgery in implant rehabilitation. While it has been demonstrated that keratinized gingiva is an important factor for implant success, there remains a dearth of case reports concerning the use of a lingual pedicle flap to achieve this desired outcome in such a large reconstructive effort. For this case report, the patient underwent an anterior mandibular resection of an ameloblastoma, and subsequent reconstruction resulting in soft tissue loss. To both functionally and esthetically satisfy the patient's desires, a bilateral rotated pedicled lingual flap was performed to augment keratinized tissue on the anterior mandibular ridge. An additional vestibuloplasty with two collagen matrices was also performed and an acrylic splint was then applied to achieve better stabilization. The primary outcome was to evaluate the efficacy of this technique, which, until now, was only used for exposed root coverage.The site demonstrated excellent healing over time, even resulting in an excess of healthy and pink soft tissue, which later had to be corrected with a small gingivectomy. Although the patient reported slight discomfort for a few days after surgery, she was nonetheless pleased both with her ability to function and her appearance. The results of this study show that the bilateral rotated pedicled lingual flap is a viable technique for the correction of soft tissue defects in implant dentistry, providing a good amount of keratinized gingiva. PMID:23425252

Herford, Alan S; Tandon, Rahul; Pivetti, Luca; Cicciù, Marco



Biomaterials in cochlear implants  

PubMed Central

The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts of the implant face considerable mechanical challenges, such as the need for the electrode array to be flexible and resistant to breakage, and for the implant casing to be able to withstand external forces. As these implants are in the immediate vicinity of the middle-ear mucosa and of the junction to the perilymph of the cochlea, the risk exists – at least in principle – that bacteria may spread along the electrode array into the cochlea. The wide-ranging requirements made of the CI in terms of biocompatibility and the electrode mechanism mean that there is still further scope – despite the fact that CIs are already technically highly sophisticated – for ongoing improvements to the properties of these implants and their constituent materials, thus enhancing the effectiveness of these devices. This paper will therefore discuss fundamental material aspects of CIs as well as the potential for their future development.

Stover, Timo; Lenarz, Thomas



The mandibular ridge oral mucosa model of stromal influences on the endothelial tip cells: an immunohistochemical and TEM study.  


This study aimed to evaluate by immunohistochemistry and transmission electron microscopy (TEM) the morphological features of the oral mucosa endothelial tip cells (ETCs) and to determine the immune and ultrastructural patterns of the stromal nonimmune cells which could influence healing processes. Immune labeling was performed on bioptic samples obtained from six edentulous patients undergoing surgery for dental implants placement; three normal samples were collected from patients prior to the extraction of the third mandibular molar. The antibodies were tested for CD34, CD117(c-kit), platelet derived growth factor receptor-alpha (PDGFR-?), Mast Cell Tryptase, CD44, vimentin, CD45, CD105, alpha-smooth muscle actin, FGF2, Ki67. In light microscopy, while stromal cells (StrCs) of the reparatory and normal oral mucosa, with a fibroblastic appearance, were found positive for a CD34/CD44/CD45/CD105/PDGFR-?/vimentin immune phenotype, the CD117/c-kit labeling led to a positive stromal reaction only in the reparatory mucosa. In TEM, non-immune StrCs presenting particular ultrastructural features were identified as circulating fibrocytes (CFCs). Within the lamina propria CFCs were in close contact with ETCs. Long processes of the ETCs were moniliform, and hook-like collaterals were arising from the dilated segments, suggestive for a different stage migration. Maintenance and healing of oral mucosa are so supported by extensive processes of angiogenesis, guided by ETCs that, in turn, are influenced by the CFCs that populate the stromal compartment both in normal and reparatory states. Therefore, CFCs could be targeted by specific therapies, with pro- or anti-angiogenic purposes. PMID:23192856

Rusu, Mugurel Constantin; Didilescu, Andreea Cristiana; St?nescu, Ruxandra; Pop, Florinel; M?noiu, Valentina Mariana; Jianu, Adelina Maria; Vâlcu, Marek



Infections in breast implants.  


Infection following breast implants is an uncommon event. This is somewhat surprising, since the human breast is not a sterile anatomical structure. The flora found in the breast are derived from the nipple ducts and closely resemble those of normal skin. These organisms, predominantly S. epidermidis, may in some cases be responsible for firmness secondary to capsular contracture. Treatment of the periprosthetic infection usually involves implant removal, but salvage by systemic antibiotics is sometimes possible. Atypical mycobacteria are very rarely the cause of infection, but can be extremely difficult to eradicate when involved. Toxic shock syndrome has been reported to occur following breast implants and is a life-threatening problem requiring immediate removal of the implant. It may be significant that in some cases with effusion and infection occurring many months or years after implant placement, there has been a preceding event such as a laryngitis or flu-like illness. This suggests the possibility of a bacteremia being involved in the causation of the infection. If this were the case, then these patients should be handled in a fashion similar to those with prosthetic heart valves. Accordingly, in our own practice, we advise that penicillin "V" be given beforehand when a patient with brea