Comparison of different designs of implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress distribution in edentulous mandible - A computed tomography-based three-dimensional finite element analysis

A finite element analysis was used to compare the effect of different designs of implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress distribution in edentulous mandible. Four models of an human mandible were constructed. In the OR (O'ring) group, the mandible was restored with an overdenture retained by four unsplinted implants with O'ring attachment; in the BC (bar-clip) -C and BC groups, the mandibles were restored with overdentures retained by four splinted implants with bar-clip anchor associated or not with two distally placed cantilevers, respectively; in the FD (fixed denture) group, the mandible was restored with a fixed full-arch four-implant-supported prosthesis. Models were supported by the masticatory muscles and temporomandibular joints. A 100-N oblique load was applied on the left first molar. Von Mises (σvM), maximum (σmax) and minimum (σmin) principal stresses (in MPa) analyses were obtained. BC-C group exhibited the highest stress values (σvM=398.8, σmax=580.5 and σmin=-455.2) while FD group showed the lowest one (σvM=128.9, σmax=185.9 and σmin=-172.1). Within overdenture groups, the use of unsplinted implants reduced the stress level in the implant/prosthetic components (59.4% for σvM, 66.2% for σmax and 57.7% for σmin versus BC-C group) and supporting tissues (maximum stress reduction of 72% and 79.5% for σmax, and 15.7% and 85.7% for σmin on the cortical and trabecular bones, respectively). Cortical bone exhibited greater stress concentration than the trabecular bone for all groups. The use of fixed implant dentures and removable dentures retained by unsplinted implants to rehabilitate edentulous mandible reduced the stresses in the periimplant bone tissue, mucosa and implant/prosthetic components. © 2013 Elsevier Ltd.

High condylectomy procedure: A valuable resource for surgical management of the mandibular condylar hyperplasia

Condylar hyperplasia is an overdevelopment of the condyle, which may manifest unilaterally or bilaterally. This pathological condition can lead to facial asymmetry, malocclusion, and dysfunction of the temporomandibular joint. The etiology and pathogenesis of condylar hyperplasia remain uncertain, but it has been suggested that its etiology may be associated with hormonal factors, trauma, and hereditary hypervascularity, affecting both genders. The diagnosis is made by clinical examination, and radiological imaging, and additionally, bone scintigraphy, is a fundamental resource for determining whether the affected condyle shows active growth. Patients with active condylar hyperplasia management have better results when they are subjected to the high condylectomy procedure. The authors report a case in a 20-year-old female subject with unilateral active condylar hyperplasia who was treated by high condylectomy. The patient has been followed up for 4 years without signs of recurrence and with good functional stability of the occlusion. © 2013 by Mutaz B. Habal, MD.

Arthrocentesis procedure: Using this therapeutic maneuver for TMJ closed lock management

Temporomandibular joint (TMJ) disorder is a term that encompasses a number of overlapping conditions, such as closed lock. Closed lock of the TMJ is considered a consequence of a nonreducing deformed disc acting as an obstacle to the sliding condylar head that usually causes a decrease in the maximum mouth opening and acute pain. The management of the TMJ is still controversial. Thus, arthrocentesis of the TMJ is a valuable modification of the traditional method of arthroscopic lavage, which consists of washing the joint in order to remove chemical inflammatory mediators and intra-articular adhesions, changing intra-articular pressure. TMJ disorder has always presented as a therapeutic challenge to maxillofacial surgeons. Therefore, this paper aimed to describe a clinical report of a closed lock of the left TMJ in a 19-year-old female subject who was successfully treated by arthrocentesis procedure. © 2013 by Mutaz B. Habal, MD.

Anatomical study of the retroarticular process in dry human skulls

Introduction: The retroarticular process is a bony prominence formed by the thickening of the lateral border of the mandibular fossa, forming the posterior wall of the temporomandibular joint. Since little is known and discussed about the retroarticular process, our aim was to study its presence, shape and size, relating these findings to the shape of the skulls according to the horizontal cephalic index. Materials and Methods: We used 400 dry human skulls of the Institute of Science and Technology - UNESP Anatomy Laboratory. Each skull was classified in brachycranics, mesocranics or dolichocranics, and then positioned on a craneostat to measure the height of the retroarticular process from its lower extremity to the auriculo-orbital plane. The width was obtained by measuring the base of the process on its longer lateral axis. Results: The retroarticular process was found bilaterally in 397 skulls (99.25%). All the processes were classified into the following shapes: pyramidal (35.55%), tubercular (31.78%), mammilar (20.73%), crest-like (9.05%) and molar shape (2.89%); 254 skulls (63.50%) showed the same type of process at the right and left sides (Kappa=0.496, moderate agreement). The average height and width were 5.28 mm and 12.81 mm, respectively. Conclusion: The retroarticular process was found in almost all the skulls examined. There are no significant evidences about the relationship among the presence, shape and size of the retroarticular process and the shape of the skulls according to the horizontal cephalic index. However, our findings led us to infer that there would be a functional relationship between the process and the temporomandibular joint.

Facial pain associated with fibromyalgia can be marked by abnormal neuromuscular control: A cross-sectional study

Background. Temporomandibular disorder (TMD) development in fibromyalgia syndrome (FMS) is not yet fully understood, but altered neuromuscular control in FMS may play a role in triggering TMD. Objective. The purpose of this study was to verify the association between neuromuscular control and chronic facial pain in groups of patients with FMS and TMD. Design. A cross-sectional study was conducted. Methods. This study involved an analysis of facial pain and electromyographic activity of the masticatory muscles in patients with FMS (n=27) and TMD (n=28). All participants were evaluated according to Research Diagnostic Criteria for Temporomandibular Disorders and surface electromyography (SEMG). Myoelectric signal calculations were performed using the root mean square and median frequency of signals. Results. The data revealed premature interruption of masticatory muscle contraction in both patient groups, but a significant correlation also was found between higher median frequency values and increased facial pain. This correlation probably was related to FMS because it was not found in patients with TMD only. Facial pain and increased SEMG activity during mandibular rest also were positively correlated. Limitations. Temporal conclusions cannot be drawn from the study. Also, the study lacked a comparison group of patients with FMS without TMD as well as a control group of individuals who were healthy. Conclusions. Altered neuromuscular control in masticatory muscles may be correlated with perceived facial pain in patients with FMS. © 2013 American Physical Therapy Association.

Endaural access to remove the projectile from a firearm

Background: Surgical approaches to temporomandibular region have been the subject of numerous controversies in the literature. Pre-auricular approaches have been used with the observance of high success rate, and during surgery history, various modifications of this approach were conducted in order to reduce irreversible sequelae. Thus, given the relevance of the study, this article proposes to alert the professionals that carry out these surgical approaches in relation to the anatomical structures involved and to describe and emphasise the benefits of endaural approach. Case report: A Caucasian male patient, victim of a firearm injury, sustained a wound on the right pre-auricular region, and at the time of assessment, he complained of pain, mouth opening difficulty and dysphagia. On physical examination, there was oedema and ecchymosis in the right periorbital region. In the radiological examination, a foreign body compatible with a firearm projectile was observed in the right pre-auricular region, being in accordance with the information collected. The endaural incision and divulsion by plans was then made until the projectile. Discussion: For proper exposure of the region, several studies were designed to evaluate the patterns of branching and anastomosis of the facial nerve. As for the best cosmetic result with the different pre-auricular approaches, the endaural approach was described as an approach that offers great cosmetic results because the incision design guides the surgeon in the wound closure and causes a decrease in the tension of flap, unlike that observed by some authors. © 2012 Springer-Verlag Berlin Heidelberg.

Impacto da dor miofascial no hábito alimentar

Pós-graduação em Alimentos e Nutrição - FCFAR

Desenvolvimento, comportamento mecânico e microestrutural de uma prótese mandibular em liga de titânio produzida por sinterização direta a laser de metal (DMLS)

Pós-graduação em Engenharia Mecânica - FEIS

Cirurgia ortognática associada á cirurgia das ATMs acometidas por artrite reumatóide ou osteocondroma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ruídos articulares em pacientes parcialmente desdentados (classe I ou II de Kennedy), antes e após a reposição dental com prótese parcial removível: avaliação através da eletrovibratografia

Pós-graduação em Odontologia - FOA

Avaliação da atividade elétrica e limiar de dor à pressão dos músculos masseter e temporal anterior com placas de diferentes espessuras

Pós-graduação em Odontologia - FOA

Avaliação comparativa da efetividade das placas oclusais confeccionadas em relação central ou máxima intercuspidação em pacientes com DTM

Pós-graduação em Odontologia - FOA

Efeito do tratamento fisioterápico sobre as vibrações das articulações temporomandibulares (ATMs) de pacientes com hipermobilidade condilar

Pós-graduação em Odontologia - FOA

Efeito da terapia com laser de baixa intensidade na dor e disfunção mandibular

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da prevalência de síndrome fibromiálgica em pacientes com DTM e estudo comparativo de aspectos clínicos e do limiar de dor à pressão

Pós-graduação em Odontologia - FOA