Análise da concavidade lingual da mandíbula por meio de tomografia computadorizada de feixe cônico: estudo retrospectivo transversal / Lingual analysis of the mandible by means of a cone-beam computed tomography study by means of a cross-sectional retrospective lingual study

O objetivo deste estudo é analisar e correlacionar características anatômicas da mandíbula posterior (presença e grau de inclinação da concavidade lingual, altura e espessura óssea) de mandíbulas edêntulas por meio de tomografias computadorizadas de feixe cônico. Material e Método: Foram selecionados cortes tomográficos transversais das hemimandíbulas, posteriores ao forame mentual 5, 10 e 15mm. Foram analisadas espessura óssea 2mm acima do canal alveolar inferior (Espessura A) e 2mm abaixo da crista alveolar (Espessura B); altura mandibular, angulação e profundidade da concavidade lingual nos gêneros. Além disso a hemimandíbula foi classificada de acordo com seu formato em U, C, P. Resultados: No corte de 10 mm a média de Espessura A foi de 11,2 ± 1,8 mm (F) e 10,5 ± 2,1 (M) (P = 0,057); a média de Espessura B foi 8,8 ± 2,9 mm (F) e 9,6 ± 2,1 mm (M)(P = 0,057); a Altura média foi de 12,7 ± 2,7 mm (F) e 15,5 ± 4,1 mm (M); a média de Ângulos da concavidade lingual foi de 64,2 ± 19,2° (F) e 66,3 ± 29,0° (M) (P = 0,006); a Profundidade da concavidade lingual foi de 3,0 ± 2,0 mm (F) e 6,8 ± 15,8 mm (M) (P = 0,033). O formato C foi o mais comum (51,9%) seguido do formato U (25%) e P (23,0%)(P = 0,001). Na correlação de cortes 5, 10 e 15 mm, a Espessura B aumentou significantemente para posterior nos formatos U e C (P=0,933). Conclusão: a concavidade lingual esteve presente na amostra estudada em 25% das tomografias. A profundidade da concavidade lingual foi maior no gênero masculino. Espessura e Altura de mandíbula posterior não variam de acordo com o gênero(AU)

The objective is to analyze and correlate the anatomical characteristics of the posterior (presence and degree of inclination of the height and bone thickness) of the analyzed mandibles through the study of computerized studies of conical height. Material and Method: Transverse tomographic sections of the hemimandibles were selected, posterior to the mental foramen at 5, 10 and 15 mm. Bone thickness was 2mm above the inferior alveolar canal (thickness A) and 2mm below the alveolar crest (thickness B); mandibular height, angulation and depth of the lingual concavity in the genera. In addition, the hemimandible was classified into U, C, P. Results: In the 10 mm section, the mean thickness A was 11.2 ± 1.8 mm (F) and 10.5 ± 2.1 (M) (P = 0.057); mean thickness B was 8.8 ± 2.9 mm (F) and 9.6 ± 2.1 mm (M) (P = 0.057); the mean height was 12.7 ± 2.7 mm (F) and 15.5 ± 4.1 mm (M); the mean lingual concavity angles were 64.2 ± 19.2° (F) and 66.3 ± 29.0° (M) (P = 0.006); the depth of the lingual concavity was 3.0 ± 2.0 mm (F) and 6.8 ± 15.8 mm (M) (P = 0.033). The C format was the most common (51.9%) followed by the U format (25%) and P (23.0%) (P = 0.001). In the thickness of slices 5, 10 and 15 mm, thickness B increased significantly for posterior and U formats (P=0.933). Conclusion: Lingual research was present in the sample in 25% of the attempts. The depth of the lingual concavity was greater in males. Posterior mandible thickness and height do not diverge according to gender(AU)

Acesso extraoral para tratamento cirúrgico de fratura de mandíbula atrófica: relato de caso / Extraoral access for surgical treatment of atrophic jaw fracture: case report

Introdução: Por sua posição na face, a mandíbula é frequentemente atingida pelos traumas, surgindo em algumas estatísticas como o osso fraturado com maior incidência em face. Em fraturas de mandíbulas atróficas o tratamento conservador, com fixação intermaxilar não costuma ser uma opção viável pela falta de dentes e pequena área de contato ósseo existente. Dessa forma, a redução aberta e fixação interna estável tem sido o tratamento de escolha sempre que a condição do paciente permitir. Objetivo: relatar um caso de osteossíntese de fratura de mandíbula atrófica por acesso extraoral. Relato de caso: Paciente 64 anos, faioderma, sexo feminino, procurou o serviço de Cirurgia e Traumatologia Bucomaxilofacial da Universidade Federal da Bahia apresentando traumatismo facial por queda da própria altura, referindo severas queixas álgicas espontâneas em região mandibular. Ao exame físico notou-se edentulismo total em ambas as arcadas, edema, hematoma e degrau ósseo á palpação em região de corpo de mandíbula a direita, alémde mobilidade atípica a manipulação da mandíbula. Ao exame de imagem notou-se sinais de fratura em corpo mandibular direito e côndilo esquerdo. O tratamento instituído foiconservador para a fratura de côndilo e cirúrgico para a fratura de corpo, o acesso foi extraoral ea fixação rígida foi realizada com placa e parafusos dos dispositivos Load-Bearing. Considerações finais: A paciente não apresentou quaisquer déficits funcionais pós-procedimento cirúrgico, sendo o tratamento abertocom fixação interna estável bastante promissor por restabelecer a união de focos fraturados e deslocados, proporcionando estabilidade da fratura e conforto imediato para a paciente(AU)

Introduction: Due to its position on the face, the jaw is frequently affected by trauma, appearing in some statistics as the fractured bone with a higher incidence in the face. In fractures of atrophic jaws, conservative treatment, with intermaxillary fixation, is not usually a viable option due to the lack of teeth and small area of existing bone contact. Thus, open reduction and stable internal fixation have been the treatment of choice whenever the patient's condition permits. Objective: to report a case of osteosynthesis of atrophic mandible fracture through extraoral access. Case report: Patient 64-year-old, female, sought the service of Maxillofacial Surgery and Traumatology at the Federal University of Bahia presenting facial trauma due to falling from his own height, referring to severe spontaneous pain complaints in the mandibular region. On physical examination, total edentulism was noted in both arches, edema, hematoma and bone step on palpation in the right jaw body region, in addition to atypical mobility in the jaw manipulation. On imaging examination, signs of fracture were noted in the right mandibular body and left condyle. The treatment instituted was conservative for condyle fracture and surgical for body fracture, access was extraoral and rigid fixation was performed with plate and screws of the Load-Bearing devices. Final considerations: The patient did not presente any functional deficits after the surgical procedure, and the open treatment with stable internal fixation is very promising for restoring the union of fractured and displaced foci, providing fracture stability and immediate comfort for the patient(AU)

Three-dimensional finite element analysis of implant stress of fixed full-arch implant-supported prosthesis on edentulous mandible in two different designs / 第二军医大学学报

Objective To design two kinds of fixed full-arch implant-supported prosthesis and to investigate their stress distribution in the different vertical heights of the edentulous mandible. Methods The cone-beam computed tomography (CBCT) scan data of the upper denture andmandible were collected to establish the base models of the mandible. The vertical heights of the mandible models were loweredby 0. 5. 10 and 15 mm. and the three-dimensional finite element models of implants with different vertical heights supported by mental foramen 6 parallel implants and supported by “All-on-Four” were established. including 2 groups (8 models); 6-implant group and 4-implant group. A 250 N vertical force was applied to the central fossa of the right mandibular first molar. The stress of each part of the models was analyzed by Ansys 15. 0 software. Results Under the same loading condition. the maximum stress value of the implantswas in the neck of the implants. The maximum stress distribution of 8 models showed that the maximum stress value was 40. 12-49. 06 MPa for the 4-implant group and was 80. 62-109. 64 MPa for the 6-implant group, with the latter being two folds that of the former. In two groups, the maximum stress was the lowest when the vertical height reduction was 5 mm. With the decrease of the mandible vertical height. the stress increased gradually. However, the maximum stress of the 0 mm-height-reduced models was larger than that of 5 mm- height-reducedmodels. Conclusion There is no destructive stress under certain extreme load in both 4-implant group and 6-implant group, with the 4-implant group having a more reasonable stress distribution. The 5 mm-hight-reduced models have the minimum stress, indicating that appropriate vertical height reduction can lead to more reasonable implant stress distribution.

Clinical evaluation of mandibular implant overdentures via Locator implant attachment and Locator bar attachment

PURPOSE: The aim of this study was to evaluate the clinical findings and patient satisfaction on implant overdenture designed with Locator implant attachment or Locator bar attachment in mandibular edentulous patients. MATERIALS AND METHODS: Implant survival rate, marginal bone loss, probing depth, peri-implant inflammation, bleeding, plaque, calculus, complications, and satisfaction were evaluated on sixteen patients who were treated with mandibular overdenture and have used it for at least 1 year (Locator implant attachment: n=8, Locator bar attachment: n=8). RESULTS: Marginal bone loss, probing depth, plaque index of the Locator bar attachment group were significantly lower than the Locator implant attachment group (P.05). The replacement of the attachment components was the most common complication in both groups. Although there was no correlation between marginal bone loss and plaque index, a significant correlation was found between marginal bone loss and probing depth. CONCLUSION: The Locator bar attachment group indicates lesser marginal bone loss and need for maintenance, as compared with the Locator implant attachment group. This may be due to the splinting effect among implants rather than the types of Locator attachment.

Reabilitação da mandíbula edêntula com implantes e coroas metalocerâmicas isoladas implantossuportadas: relato de caso clínico com sistema CAD/CAM / Rehabilitation of the edentulous mandible using single-tooth, implant-supported metal-ceramic crowns: case report with CAD/CAM system

A forma mais comum de reabilitação de mandíbulas edêntulas com implantes osseointegrados é a prótese total fixa parafusada tipo protocolo de Brånemark, na qual os implantes são esplintados. Este relato de caso clínico apresenta uma forma alternativa de reabilitação total de mandíbulas edêntulas, com 14 implantes cone-morse e coroas totais metalocerâmicas isoladas. Foram discutidos aspectos referentes ao planejamento, com ênfase no planejamento virtual, na necessidade de disponibilidade óssea para realização deste tipo de tratamento, nas facilidades de higienização desta modalidade de reabilitação, nas considerações biomecânicas do caso, sobretudo quanto aos possíveis riscos em manter os implantes isolados, na seleção adequada dos implantes e dos componentes protéticos, nos benefícios do conceito de platform switching incorporados aos implantes cone-morse, nos cuidados necessários de manutenção, entre outros aspectos. A técnica é extremamente delicada em todas as suas etapas, sobretudo nas fases de planejamento e cirúrgica, visando a excelência do posicionamento dos implantes, para permitir a utilização de componentes protéticos pré-fabricados (munhões universais retos) sem a necessidade de usinagem. Este tipo de reabilitação mandibular mostrou-se muito eficiente, apresentando como principais vantagens a estética otimizada, a facilidade de higienização, o aspecto emocional muito favorável e uma extrema satisfação da paciente.

The most common treatment type for edentulous mandible is the full-fixed prosthesis according to the Branemark protocol with splinted dental implants. This case report presents an alternative option with cone Morse implants, straight universal abutments, and single metal-ceramic crowns. Aspects such as virtual implant planning, bone availability, biomechanical risks for single-tooth implants, prosthetic component selection, platform-switching, and maintenance are discussed, among others. The technique is very delicate in each step, particularly at surgery and three-dimensional implant positioning for pre-fabricated prosthetic components (straight universal abutments) without previous modifications. This kind of mandibular rehabilitation was very efficient and has the advantages of esthetics, easy cleaning, favorable emotional aspects and good patient satisfaction.

Morphometric study of mental foramina in dentate and edentulous human mandible in Gujarat Region.

Background & Objectives: will be useful for anatomists, anthropologists, aneasthetist, orthopedics and experts in the field of forensic medicine. The aim of the study was to examine the different morphometric variations of the human mandibles and comparing between dentate and edentulous mandibles is done. Methods: This study included only bone who exhibited no obvious bone pathology. All measurements were done bilaterally, performed with a stainless steel metric digital calliper with 0.01 mm precision. The relative position of the Mental foramena (MF)as analyzed with measurements made from nferior wall of mandible to the mandibular base, from anterior wall of mandible to the mandibular skeletal midline, from his posterior wall to the posterior mandibular rim. To determine this relation, the standard horizontal plane defined by Morrant was used. Briefly, the mandible was placed on a horizontal surface, to which the lower border of the mandible comes into greatest contact when vertical pressure is applied to the second molar teeth. Results: The most common location for the MF is a position aligned between second premolar and first molar (Rt. side 30% & Lt. Side 31%). Comparison of measurements of dentate and edentulous mandible is significnat on both sides. Conclusion: The knowledge of the distances from surgically encountered anatomical landmarks in the present study provide valuable information to dental surgeons that will facilitate effective localization of the neurovascular bundle passing through mental foramen thus avoiding complications from local anesthetic, surgical and other invasive procedures.

Case Reports On The Magnetic Retained Overdentures / 대한치과보철학회지

The purpose of this study was to evaluate a cases which was treated with magnetic attachments on the patients in edentulous mandible and maxilla.Author made magnetic overdenture for two patients and then clinical examination were used for evaluation of the function and change in retention during 30months.Patients showed difficulty in oral hygiene care at the beginning but they go used to it soon. It was effective in promotion of denture retention and stability and also gave patient emotionally uplifting psychologic state.This study suggest that magnetic attachment was effective for the treatment of patients presenting a few remaining teeth or teeth under severe caries or mobility.

A SUTDY ABOUT THE SHAPE OF THE FRAMEWORK OF THE FIXED BONE ANCHORED BRIDGE USING DENTAL IMPLANTS / 대한치과보철학회지

The purpose of this study was pertinent design of the framework of the fixed bone anchored bridge using implants in the edentulous mandible through analysis of stress distribution by the three dimensional finite element analysis method. The results were as follows: 1. The L-shaped framework was favorable in restoring the edentulous mandible by implants and fixed bone anchored bridge. 2. The structure of the framework should be designed to endure the occlusal load because of stress concentration at the most distal abutment of the framework. 3. The stress at the distal implant where cantilever starts was twice as much as that of other portions. 4. Compressive stress was generated on the framework of the mesial side of the distal implant and extrusive force was induced to the mesially positioned implants. 5. The height of vertical plate was high as possible as can be to distribute stresses concentrating bucco-lingually and labio-lingually in the framework between abutments, 6. Reinforcement of the horizontal plate thickness was needed because stress was loaded more on the horizontal plate than on the vertical plate of the framework. 7. Lengthening of the vertical plate can compensate for any limitations in horizontal plate width.