Photoelastic Analysis of Stress Distribution in Oral Rehabilitation

The purpose of this study was to present a literature review about photoelasticity, a laboratory method for evaluation of implants prosthesis behavior. Fixed or removable prostheses function as levers on supporting teeth, allowing forces to cause tooth movement if not carefully planned. Hence, during treatment planning, the dentist must be aware of the biomechanics involved and prevent movement of supporting teeth, decreasing lever-type forces generated by these prosthesis. Photoelastic analysis has great applicability in restorative dentistry as it allows prediction and minimization of biomechanical critical points through modifications in treatment planning.

Management of Orbital Reconstruction

One of the concerns after a major trauma to the orbit is to be rebuilt. This can be achieved with care in management of orbital reconstruction, techniques, types of materials, and osseointegrated implants; it allows satisfactory aesthetic recuperation and well-being, whereas psychological therapy allows for patients' re-insertion in social and family environment to make them feel happier and safer.

Photoelastic Analysis of Implant-Retained and Conventional Obturator Prostheses With Different Attachment Systems and Soft Relining

Complete and partial loss of maxillary bone may jeopardize oral physiology and generate complications as oral-sinus-nasal communication. Palatal obturator prostheses are a treatment alternative for rehabilitation of these patients. The aim of this study was to assess stress distribution, through photoelasticity, on palatal obturator prostheses associated with different attachment systems (o'ring, bar clip, and o'ring/bar clip) of implants and submitted to relining. Two photoelastic models were fabricated according to an experimental maxillary model with oral-sinus-nasal communication. One model did not present implants, whereas the other included 2 implants with 13.0 mm in length in the left ridge. Four colorless maxillary obturator prostheses were fabricated and relined with soft silicone. One of these prostheses presented no attachment system, whereas the remaining prostheses included attachment systems adapted to the implants. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope during loading with 100 N at 10 mm/s. The results were based on observation during the experiment and photographic records of stress on the photoelastic model. The bar clip system exhibited the highest stress concentration followed by o'ring/bar clip and o'ring systems. The attachment systems presented different stress distribution with greater concentration surrounding the implants and homogenous stress distribution on the photoelastic model without implants. The highest concentration of fringes occurred, in ascending order, with o'ring, o'ring/bar clip, and bar clip systems.

Evaluation of the Shore A Hardness of Silicone for Facial Prosthesis as to the Effect of Storage Period and Chemical Disinfection

The failure of facial prostheses is caused by limitations in the properties of existing materials, especially flexibility and durability. Therefore, this study evaluated the Shore A hardness of silicone used for fabrication of facial prostheses, Silastic MDX4-4210, according to the influence of storage period, daily disinfection, and 2 types of pigmentation. Thirty specimens were fabricated and divided in 3 groups: colorless, pigmented with makeup, and pigmented with iron oxide. Analysis of results was assessed on a Shore A hardness meter immediately, 6 months, and 1 year after fabrication of specimens, following the guidelines of the American Society for Testing and Materials. The hardness values were statistically analyzed by the Tukey test. The silicone exhibited an increase in hardness with time. However, the hardness was stable from 6 months to 1 year. It was concluded that the silicone is within the values of Shore A hardness reported in the literature, regardless of the storage period, pigmentation, and chemical disinfection.

Color Stability of Polymers for Facial Prosthesis

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

Surgical and Prosthetic Rehabilitation of Patients With Hemimandibular Defect

Purpose: This work intended to investigate, by means of a literature revision, the techniques and materials used for the rehabilitation of hemimandibular defect patients, prosthetic and occlusal aspects of these patients, and chewing and swallowing.Materials and Methods: For the confection of this revision, we consulted the database indexers Google Scholar, PubMed, and SciELO and found studies published between the periods 1972 and 2008. The terms used for the search had been "to hemimandibular defects," "to temporomandibular joint protheses," and "vascularized cap grafts," which had been searched separately and combined.Conclusions: Diverse techniques and materials used for the reconstruction of hemimandibular defects exist; however, great bone resorption is still observed, which will compromise the prosthetic rehabilitation of these patients. More prospective works and stories of clinical cases duly registered will be able to elucidate in a clearer form the anatomic and functional devolutions of the verbal socket of hemimandibular defect patients.

Mobility, Aesthetic, Implants, and Satisfaction of the Ocular Prostheses Wearers

During the process of facial rehabilitation, the mobility of ocular prostheses must be considered. Whereas some factors depend exclusively on the dentist, such as molding techniques and selection of material for denture construction, regarding ocular rehabilitation, factors, such as type of surgery, whether to adopt implants, and the use of lubricants, deserve special attention owing to their integration and their association with other factors pertaining exclusively to the patient. To establish harmony, and with the intention of aiding the dentist, after a discerning evaluation, the authors of this study report the factors that provide greater or less mobility to ocular prostheses and conceal the prosthesis in a more natural way, thereby contributing toward achieving a favorable aesthetic result in rehabilitations.

Interceptive Approach to Treatment of Impacted Maxillary Canines

Impaction of maxillary canines can be prevented by early intervention in the mixed dentition phase after the correct diagnosis of malocclusion, reducing the complexity of the treatment. This article reports the case of a 10-year-old patient who possessed impacted maxillary canines and, after early extraction of primary canines, had reestablished favorable permanent successors' eruption axis. This 5-year radiographic follow-up study with panoramic radiography shows that this can be used in practice and that an effective control strategy ensures the accuracy in the inclination of the impacted canines. Treatment success is related to early diagnosis and strategic interceptive treatment choice.

Avaliação da reprodutibilidade do método de determinação da maturação esquelética por meio das vértebras cervicais

Dentre os diversos meios de se determinar o grau de maturação esquelética do paciente destaca-se o Método de Lamparski modificado por Hassel e Farman, em 1995, que propuseram a identificação do estágio da maturação por meio das modificações anatômicas das 2ª, 3ª e 4ª vértebras cervicais. Cientes das qualidades advogadas ao método citado surgiu o interesse em avaliar sua reprodutibilidade com o intuito de divulgá-lo e incorporá-lo como um elemento no diagnóstico e auxiliar no prognóstico dos tratamentos das más oclusões. A amostra constou de 100 telerradiografias em norma lateral de pacientes triados para tratamento ortodôntico na Faculdade de Odontologia de Araçatuba - UNESP nos períodos de 2000 e 2001. Foram incluídos pacientes de ambos os gêneros na faixa etária de 6 a 16 anos e a média de 9 anos e 7 meses. Três examinadores devidamente calibrados realizaram a avaliação das radiografias classificando-as em escores de 1 a 6. Após a análise dos resultados, os mesmos foram tabulados e submetidos ao coeficiente Kappa de concordância para avaliação inter e intra-examinador concluindo, dessa forma, a reprodutibilidade do referido método. O método de determinação da maturação esquelética por meio das vértebras cervicais mostrou-se reproduzível na avaliação do estágio em que o indivíduo se encontra na curva de crescimento.

Tratamento da má oclusão de Classe II, divisão 1 de Angle, com protrusão maxilar utilizando-se recursos ortopédicos

OBJETIVO: o presente trabalho tem o propósito de apresentar uma revisão da literatura acerca do tratamento da má oclusão de Classe II, divisão 1 de Angle, tendo a protrusão maxilar como o principal componente dessa má oclusão, durante a fase de crescimento e desenvolvimento craniofacial. Serão apresentadas as características de cada um desses aparelhos, os seus componentes, a forma adequada de utilização, os seus mecanismos de ação e, principalmente, os seus efeitos em todo o complexo dentofacial. CONCLUSÃO: nos casos em que se verifica apenas a protrusão maxilar, sem envolvimento mandibular, e se faz necessário o controle vertical, pode ser indicado o AEB, conjugado ao aparelho removível derivado do aparelho preconizado por Thurow. Já nas situações de combinação da protrusão maxilar com a retrusão mandibular, uma opção de tratamento é o ativador combinado à ancoragem extrabucal.

Morfologia das 3ª e 4ª vértebras cervicais representativa do surto de crescimento puberal

OBJETIVOS: determinar a morfologia das 3ª e 4ª vértebras cervicais representativa dos estágios de pré-pico, pico e pós-pico de velocidade de crescimento estatural, definidos previamente pelos centros de ossificação do primeiro dedo em radiografias carpais ou do dedo polegar. MÉTODOS: foram utilizadas 120 telerradiografias em norma lateral de 106 pacientes selecionados da clínica de Ortodontia Preventiva e Interceptiva da Faculdade de Odontologia de Araçatuba-UNESP e Profis/HRAC-USP que apresentavam as correspondentes radiografias carpais ou do dedo polegar. As telerradiografias foram divididas em três grupos de 40 radiografias, de acordo com os estágios maturacionais pré-pico, pico e pós-pico, definidos pela imagem do primeiro dedo. A morfologia dos corpos das 3ª e 4ª vértebras cervicais foi determinada por dois examinadores devidamente calibrados em dois tempos diferentes. CONCLUSÕES: concluiu-se que o formato retangular horizontal com borda inferior reta foi representativo do estágio de pré-pico, independentemente da vértebra analisada. Já o formato retangular horizontal com borda inferior curva, especialmente se encontrado em C4, ou o formato quadrado com borda inferior reta caracterizaram o pico de velocidade de crescimento. O formato quadrado ou, principalmente, o retangular vertical com borda inferior curva determinaram o estágio de pós-pico de velocidade de crescimento da adolescência.

Avaliação cefalométrica do tratamento da Classe II, divisão 1, de Angle com os aparelhos extrabucal de Kloehn e fixo edgewise: influência do padrão facial

O presente estudo foi realizado com o propósito de avaliar respostas cefalométricas ao tratamento com aparelho extrabucal de Kloehn associado ao aparelho fixo edgewise convencional. Telerradiografias iniciais (T1) e finais (T2) de dois grupos de 30 pacientes tratados com estes aparelhos foram selecionadas e definidas pelo índice cefalométrico de Jarabak para determinação do padrão esquelético craniofacial. Os grupos foram denominados favorável (hipodivergente) e desfavorável (hiperdivergente). A idade média, no início do tratamento, foi de 11,03 anos e final de 14,72 com o tempo médio de tratamento de 3,6 anos para o grupo favorável. No grupo desfavorável a idade inicial foi de 11,51 anos e final de 15,17 anos com tempo médio de tratamento de 3,4 anos. Foi utilizado um sistema de análise de resposta de tratamento em coordenadas X e Y representativos dos movimentos dentários e das bases ósseas decompondo-os em seus vetores horizontais e verticais. Os resultados e respostas do tratamento foram analisados e comparados entre os grupos favorável e desfavorável utilizando o teste t-Student. Os resultados mostraram não haver diferenças estatisticamente significantes na resposta cefalométrica no tratamento com o aparelho extrabucal de Kloehn associados ao aparelho fixo edgewise quanto aos padrões faciais favorável e desfavorável. O tratamento promoveu uma restrição do deslocamento anterior maxilar e um menor deslocamento anterior mandibular. Quanto à movimentação dentária maxilar, houve uma restrição do movimento mesial e extrusivo dos molares superiores no grupo favorável, enquanto que o movimento dos dentes inferiores foi mínimo no sentido anterior e vertical.

Congenital fistulae of the lower lip in Van der Woude syndrome: A histomorphological study

Objective: To evaluate a significant number of cases of fistulae of the lower lip with the light microscope in order to investigate the histological variation and to attempt to define the histopathological pattern of the lesion.Methods: Congenital fistulae of the lower lips of 17 patients with Van der Woude syndrome were analyzed by light microscopy,Results and Conclusion: the walls of most of the fistulae consisted of stratified nonkeratinized squamous epithelium and a lamina propria of dense connective tissue with areas of lymphohistiocytic inflammatory infiltrates. Bundles of striated muscle fibers, blood vessels, nerves, adipose tissue, and mixed acinar glands were observed. These glands surrounded the entire wall of the lesion, and their excretory ducts opened into the lumen of the fistula, explaining the clinical observation of elimination of mucous secretion through the opening of the fistula, Two microform cases of fistula were analyzed that presented only a depression in the epithelium at the site corresponding to the opening of the fistula.

Mandibular Angle Fracture Treated With New Three-Dimensional Grid Miniplate

Fractures of the mandibular angle deserve particular attention because they represent the highest percentage of mandibular fractures and have the highest postsurgical complication rate, making them the most challenging and unpredictable mandibular fractures to treat. Despite the evolution in the treatment of maxillofacial trauma and fixation methods, no single treatment modality has been revealed to be ideal for mandibular angle fractures. Several methods of internal fixation have been studied with great variation in complications rates, especially postoperative infections. Recently, new studies have shown reduction of postsurgical complications rates using three-dimensional plates to treat mandibular angle fractures. Nevertheless, only few surgeons have used this type of plate for the treatment of mandibular angle fractures. The aim of this clinical report was to describe a case of a patient with a mandibular angle fracture treated by an intraoral approach and a three-dimensional rectangular grid miniplate with 4 holes, which was stabilized with monocortical screws. The authors show a follow-up of 8 months, without infection and with occlusal stability.

Relationship Between the Prevalence of the Dentigerous Cyst and the Odontogenic Keratocyst Tumor and the Current Etiologic Hypothesis

Cysts are considered as nonneoplastic benign lesions that, when present for a long period of time, can cause some discomfort, especially related to the treatment form. Among the types of cysts of the maxilla, the dentigerous cyst (DC) presents substances between the dental follicle and the crown of the tooth with high potential for resorption, and the odontogenic keratocyst tumor (OKT) characterizes for its noticed rapid growth pattern and the possibility to develop carcinomas in the lesion wall. The DC is the most common type among the developing odontogenic cystic lesions, while the OKT represents 10% of these lesions. The prevalence of the OKT found in the current study was superior to the DC, opposing data of the evaluated literature, as well as the predominance in relation to the age group. Dentigerous cyst cases were found mostly in younger individuals, whereas the OKT was observed mainly in individuals between the third and fourth decades of life. This fact reflects the fragility of these features while establishing the presumptive diagnosis and insinuates the strong relation with a probable genetic predisposition. In relation to sex and race, the findings in this article were similar to those found in the literature, highlighting the possibility of a hormonal involvement. However, the anatomopathologic examination remains essential to define the main diagnosis of the lesions observed by means of imaging examinations, providing for safer diagnoses to plan the treatment.