Correção da má oclusão de classe II com propulsor mandibular: revisão de literatura / Correction of class II malocclusion with mandibular trusters: literature review

Introdução: a má oclusão de classe II consiste no desequilíbrio da relação entre as arcadas, podendo ser causada por deficiência mandibular, protrusão maxilar, ou ambas, sendo caracterizada pelo molar inferior distalmente posicionado em relação ao molar superior. Objetivo: este estudo tem o objetivo de apresentar uma revisão de literatura sobre a eficiência dos propulsores mandibulares fixos disponíveis no mercado odontológico no tratamento da má oclusão de classe II. Métodos: a pesquisa foi realizada nas bases de dados Google Acadêmico, SciELO e PubMed, para filtragem dos artigos selecionados. Para revisão de literatura, foram utilizados 17 artigos. Entre os protocolos de tratamento de classe II, esses aparelhos se destacam por serem fixos, por esse motivo, não dependem da colaboração direta do paciente. Com o passar dos anos, os propulsores mandibulares fixos foram cada vez mais aprimorados, oferecendo mais simplicidade na sua instalação e maior conforto ao paciente. Considerações finais: concluiu-se que os aparelhos funcionais propulsores mandibulares fixos são uma ótima escolha para o tratamento compensatório na má oclusão de classe II, sendo eficazes na correção da relação dentária e dependendo de menor cooperação do paciente.(AU)

Introduction: class II malocclusion consists of an imbalance in the relationship between the arches, which can be caused by mandibular deficiency, maxillary protrusion, or both, and is characterized by the mandibular molar distally positioned in relation to the maxillary molar. Objective: this study aims to present a literature review on the efficiency of fixed mandibular thrusters available in the dental market in the treatment of Class II malocclusion. Methods: the research was carried out in the Google Scholar, SciELO and PubMed databases to filter the selected articles. For literature review, 17 articles were used. Among Class II treatment protocols, these devices stand out for being fixed, for this reason, they do not depend on the direct collaboration of the patient. Over the years, fixed mandibular thrusters have been increasingly improved, offering more simplicity in their installation and greater comfort to the patient. Final considerations: it was concluded that the fixed mandibular thrusters functional devices are a great choice for compensatory treatment in Class II malocclusion, being effective in correcting the dental relationship and depending on less patient cooperation.(AU)

Validação do protocolo de avaliação miofuncional orofacial MBGR para adultos com disfunção temporomandibular com deslocamento de disco com redução / Validation of the MBGR orofacial myofunctional assessment protocol for adults with temporomandibular disorders with disc displacement with reduction

RESUMO Objetivo Este estudo visou validar o Protocolo de Avaliação Miofuncional Orofacial MBGR para adultos com DTM. Método Participaram 30 adultos, sendo 15 com DTM (deslocamento de disco com redução segundo o Research Diagnostic Criteria for Temporomandibular Disorders) e 15 Controles. O processo de validação envolveu a validade de conteúdo, de critério e de construto, além da concordância inter e intra-avaliador, sensibilidade e especificidade. Considerou-se nível de significância de 5%. Resultados Foram confirmadas as validades de conteúdo, visto que o Protocolo MBGR abarca todas as questões funcionais presentes em indivíduos com DTM; de critério, com correlações significantes entre o MBGR e AMIOFE; e de construto, diferenciando indivíduos com e sem DMO quanto à dor à palpação e mobilidade mandibular, com correlação significante entre a avaliação clínica do MBGR e o uso do algômetro digital, bem como confirmação do exame instrumental para a classificação do modo respiratório. A força de concordância variou de pobre a muito boa para a análise interavaliador e de razoável a muito boa para intra-avaliador. Os valores de sensibilidade e especificidade foram elevados. Conclusão O Protocolo MBGR mostrou-se válido para aplicação em adultos com DTM com deslocamento de disco com redução e controles, contemplando todos os aspectos que possibilitam a análise das condições oromiofuncionais nesses indivíduos.

ABSTRACT Purpose This study aimed at validating the MBGR Orofacial Myofunctional Assessment Protocol (MBGR Protocol) for adults with Temporal Mandibular Disorders (TMD). Methods The study sample was composed of 30 adults: 15 with TMD (disc displacement with reduction according to the Research Diagnostic Criteria for Temporomandibular Disorders) and 15 control individuals. The validation process encompassed the content, criterion, and construct of the protocol, as well as its inter- and intra-rater agreement levels and sensitivity and specificity values, considering a 5% statistical significance level. Results The following validities were confirmed: of content, as the MBGR Protocol covers all functional issues present in patients with TMD; of criterion, with significant correlations between the MBGR and Orofacial Myofunctional Evaluation with Scores (OMES) protocols; of construct, differentiating individuals with and without Orofacial Myofunctional Disorders (OMD) as for pain on palpation and mandible range of motion, with significant correlation between the MBGR clinical evaluation and that using a digital algometer, as well as confirmation of the instrumental assessment for the breathing mode classification. Agreement ranged from poor to very good and from reasonable to very good for the inter- and intra-rater power analyses, respectively. High sensitivity and specificity values were observed. Conclusion The MBGR Protocol proved to be valid for use in adults presented with TMD with disc displacement with reduction and controls, covering all aspects that enable the analysis of OMD in these individuals.

Correlation between the cephalometric measurements and acoustic properties of /s/ sound in Turkish

Abstract Objectives To evaluate the acoustic properties of the /s/ sound in individuals with different occlusion types and to investigate relationships between these properties and cephalometric measurements. Methodology Sixty patients were divided into three groups based on malocclusion. Group 1 included 20 patients (mean age: 14.85±2.01 years) with Class I skeletal and dental relationships. Group 2 included 20 patients (mean age: 13.49±1.78 years) with Class II skeletal and dental relationships. Group 3 included 20 patients (mean age: 12.46±2.62 years) with Class III skeletal and dental relationships. Cephalometric tracings were obtained from cephalometric radiographs. All included patients were native speakers of Turkish. The /s/ sound was selected for center of gravity analysis. Correlations between cephalometric values and acoustic parameters were also investigated. Results The center of gravity of the /s/ sound had the lowest value in Group 2 (p<0.05). For the /s/ sound in Group 3, moderate positive correlations were found between center of gravity and Sella-Nasion to Gonion-Gnathion angle (p<0.05, r=0.444) Lower incisor to Nasion-B point (p<0.023, r=0.505), and Lower incisor to Nasion-B point angle (p<0.034; r=0.476). No correlation was found in other cephalometric measurements. Conclusions The /s/ sound was affected by malocclusion due to the changing place of articulation. Therefore, referral to an orthodontist for malocclusion treatment especially patients with class III in the early period is suggested for producing acoustically ideal sound.

Application of 3D Electromagnetic Articulography in Dentistry: Mastication and Deglutition Analysis. Protocol Report / Aplicación de la Articulografía Electromagnética 3D en Odontología: Análisis de la Masticación y Deglución. Reporte de Protocolo

ABSTRACT: The Stomatognathic System (SS) is an integrated and coordinated morphofunctional unit, consisting of skeletal, muscular, angiological, nervous, glandular and dental structures that work in harmony to perform different functions such as chewing, swallowing, speaking, breathing, tasting and esthetics. The study of SS physiology is crucial to achieving a correct maintenance of its normal function or restoration. Thus, we developed a protocol to record mandibular movement, chewing and swallowing (saliva and water) by using the 3D-electromagnetic articulograph AG501 at the Oral Physiology Laboratory of the Research Centre for Dental Sciences (CICO). This tool has been used for decades in speech and phonetic research and it is able to record, present and evaluate articulated structure movement data in real time. The articulograph provides an ordered data matrix (values ??for the x, y, z axes, among others) for the recorded movement, which is stored in binary files that can be processed by different software. One of these is MATLAB®, allowing us to perform a quick, clear and understandable analysis. The existence of a standardized methodology for recording allows an accurate description of the stages to perform different types of measurements according to the researcher's objective. This has opened the way for a new type of oral physiology analysis based on study reproducibility, which is considered one of the bases of scientific methodology.

RESUMEN: El Sistema Estomatognático es una unidad morfo-funcional integrada y coordinada, constituida por estructuras esqueléticas, musculares, angiológicas, nerviosas, glandulares y dentales que actúan en armonía para realizar diferentes funciones como la masticación, deglución, fonoarticulación, respiración, degustación y estética. Es importante el estudio de la fisiología del SE para lograr un correcto mantenimiento de su función normal, o para la restauración de este. Es así como en el Laboratorio de Fisiología Oral del Centro de Investigación en Ciencias Odontológicas (CICO) hemos desarrollado un protocolo para el registro del movimiento mandibular, masticación y deglución (saliva y agua), utilizando el articulógrafo electromagnético 3D AG501, el cual ha sido utilizado desde hace décadas en la investigación del habla y la fonética y que es capaz de grabar, presentar y evaluar en tiempo real datos del movimiento de estructuras articuladas. El articulógrafo provee de una matriz de datos ordenados (valores para los ejes x, y, z, entre otros) para el movimiento registrado, el cual se almacena en archivos binarios que pueden procesarse a través de diferentes softwares. Uno de ellos es MATLAB®, el cual nos permite realizar un análisis de forma rápida, clara y comprensible. La existencia de una estandarización metodológica de registro, permite describir de forma exacta las etapas para llevar a cabo distintos tipos de mediciones según el objetivo del investigador. De esta forma se abre la puerta a una nueva forma de análisis en la fisiología oral que se sustenta en la reproducibilidad de la investigación que es considerada una de las bases de la metodología científica.

One-year prospective clinical study comparing patient satisfaction and masticatory performance of mandibular overdentures supported by one versus two implants

Abstract There is a lack of clinical evidence on mandibular overdentures (MOD) supported by a single implant. Objective: To compare patient satisfaction and masticatory performance in MOD supported by one versus two implants in a two-group parallel randomized clinical trial. Material and Methods: Twenty-one patients wearing new maxillary and mandibular complete dentures (CDs) were randomly divided to receive one (GI, n = 11) or two (GII, n = 10) implants in the mandibular arch. Four months after implant placement, o-ring abutments were installed in the implants, and matrix attachments were placed in the lower complete dentures. Patient satisfaction with their dentures and masticatory performance were compared at baseline, 3, 6, and 12 months after the procedure. Data on patient satisfaction were analyzed using the Friedman test and the Mann-Whitney U test. Data on masticatory performance were analyzed using one-way repeated measures analysis of variance (ANOVA) and Student's t test (α=0.05). Results: Both groups exhibited a significant increase in overall patient satisfaction in all periods evaluated (p<0.05), except for GI after 12 months, which had values similar to baseline (p=0.74). Satisfaction levels of GI and GII were similar at baseline, 3 and 6 months, but GII showed higher satisfaction levels (p=0.01) than GI at 12 months. GI and GII exhibited a significant increase (p<0.05) in masticatory performance for all periods relative to baseline. However, GII had higher masticatory performance with dentures than GI, regardless of the period (p<0.05). Conclusion: MOD supported by two implants demonstrated better patient satisfaction in the follow-up at 12 months and better masticatory performance than MOD supported by one implant.

Manual reduction of articular disc after traumatic extraction of mandibular third molar: a case report

Introduction: Disc displacement without reduction with limited opening is an intracapsular biomechanical disorder involving the condyle-disc complex. With the mouth closed, the disc is in an anterior position in relation to the condylar head and does not reduce with mouth opening. This disorder is associated with persistent limited mandibular opening.Case report:The patient presented severe limitation to fully open the mouth, interfering in her ability to eat. Clinical examination also revealed maximum assisted jaw opening (passive stretch) with less than 40 mm of maximum interincisal opening. Magnetic resonance imaging was the method of choice to identify the temporomandibular disorders.Conclusion: By means of reporting this rare case of anterior disc displacement without reduction with limited opening, after traumatic extraction of a mandibular third molar, in which manual reduction of temporomandibular joint articular disc was performed, it was possible to prove that this technique is effective in the prompt restoration of mandibular movements.

Introdução: o deslocamento do disco articular sem redução com abertura limitada é uma desordem intracapsular que envolve o complexo côndilo-disco. Na posição de boca fechada, o disco articular se encontra numa posição anterior em relação à cabeça da mandíbula e não sofre redução com a abertura de boca. Essa desordem está associada à abertura mandibular limitada e persistente.Caso clínico:o paciente relatava travamento da mandíbula que não permitia uma abertura completa da boca, interferindo, assim, na capacidade de se alimentar. Também era possível observar-se uma abertura assistida (alongamento passivo) com uma distância vertical menor que 40 mm entre os incisivos. A ressonância magnética foi o método de escolha para o diagnóstico das desordens temporomandibulares.Conclusão:por meio da descrição de um caso raro de deslocamento anterior do disco articular sem redução e com abertura limitada, após exodontia traumática do terceiro molar inferior, em que foi realizada a redução manual do disco articular da articulação temporomandibular, provou-se ser essa uma técnica eficaz no rápido restabelecimento dos movimentos mandibulares.

Myofunctional orofacial examination: comparative analysis in young adults with and without complaints / Análise comparativa das informações de exame clínico miofuncional orofacial em adultos jovens com e sem queixas

PURPOSE: To verify myofunctional orofacial characteristics in young adults and to compare data on individuals with and without myofunctional complaints, aiming to identify the main myofunctional problems and differentiating them from characteristics that are common for this population, as well as to list items for myofunctional evaluation in this population. METHODS: Cross-sectional study with 85 adult participants, aged between 19 and 39 years, selected through consecutive sampling at the Department of Speech, Language and Hearing Sciences of Universidade Veiga de Almeida. The participants were divided into two groups: G1 (comprising 50 individuals referred for orofacial myofunctional disorders) and G2 (comprising 35 volunteers without complaints). Descriptive evaluation of craniofacial structures of hard and soft tissues, kinesiology and mandible range of motion and functional patterns of breathing, chewing, and swallowing was applied. Three expert Speech-Language pathologists assessed all participants. Statistical analysis was done using χ2-test, Student's t-test, or Mann-Whitney test. The reliability level was 99%. RESULTS: A predominance of Angle Class I pattern of occlusions for G2 (p<0.0001) was found. G1 showed (p<0.0001) mandible movements with deviations and joint noises, amplitude reduction in lateral and protrusive movements, unilateral chewing, nonexpected muscle contraction, temporomandibular joint noises, swallowing with excessive contraction of the orbicularis oris muscle, loud noise, and residues (p=0.006). CONCLUSION: The main myofunctional orofacial alterations in young adults with complaints refer to changes of the mandibular movements and patterns of chewing or of swallowing, reflecting the main items of the clinical evaluation. Many items of assessment and characterization do not differ between the groups, and these should be analyzed regarding their relevance. .

OBJETIVO: Verificar as características miofuncionais orofaciais em adultos jovens e analisar comparativamente dados de indivíduos com e sem queixas miofuncionais, visando apontar os principais problemas miofuncionais e diferenciando-os de características típicas dessa população, além de elencar os itens de avaliação miofuncional que possam merecer maior atenção para essa população. MÉTODOS: Estudo transversal com 85 participantes adultos, 19 a 39 anos, selecionados por amostra consecutiva no Serviço de Fonoaudiologia da Universidade Veiga de Almeida, divididos em dois grupos - G1: 50 indivíduos encaminhados por queixas miofuncionais orofaciais; G2: 35 indivíduos voluntários sem queixas. Todos foram avaliados por três fonoaudiólogos, especialistas. O exame constou de avaliação clínica descritiva quanto às estruturas craniofaciais de tecidos duros e moles, análise dos movimentos mandibulares, verificação funcional quanto à respiração, mastigação e deglutição. Análise estatística: teste do χ2, teste t de Student ou de Mann-Whitney. Foi adotado nível de confiabilidade de 99%. RESULTADOS: Constatou-se predomínio de oclusão Classe I de Angle para G2 (p<0,0001). G1 apresentou (p<0,0001): movimentos mandibulares com desvios e ruídos articulares, amplitude reduzida nos movimentos de lateralidade e protrusivos, mastigação unilateral, contração muscular não esperada, ruídos articulares, deglutição com contração perioral excessiva, ruído evidente e resíduos (p=0,006). CONCLUSÃO: As principais alterações miofuncionais orofaciais em adultos jovens com queixas referem-se a modificações dos movimentos mandibulares, dos padrões de mastigação ...

Protocolo inferior em paciente submetido a radioterapia: relato de caso / Lower protocol in patient submitted toradiotherapy: case report

Introdução: a combinação de cirurgia e radioterapia é comum para o tratamento de tumores malignos de cabeça e de pescoço, determinando alterações teciduais, como mucosa fragilizada, xerostomia, anatomia inadequada e distúrbios miodinâmicos, dificultando as funções bucais e a reabilitação bucal convencional do paciente. Nesses casos, a instalação de próteses implantossuportadas pode ser muito útil à reabilitação desses pacientes. Esse trabalho relata o caso de um paciente submetido a alta dose de radioterapia, após o tratamento cirúrgico de um tumor maligno em assoalho de boca. Métodos: foram instalados seis implantes na região anterior de mandíbula e confeccionada uma prótese conforme o protocolo de Brånemark. Conclusão: conclui-se que implantes osseointegráveis podem ser seguramente utilizados, tomando-se alguns cuidados especiais em relação aos efeitos adversos da ressecção e radioterapia. Melhorias na mastigação, fonação e estética facilitam a reintegração social desses pacientes, minimizando seu desconforto e sofrimento, além de otimizar os resultados terapêuticos e a qualidade de vida.

Introduction: Combining surgery and radiotherapy is common to treat malignant tumors of the head andneck. Such procedure establishes tissue alterations that result in fragile mucosa, xerostomia, improper anatomicalshape and myodynamic disorders, which hinders patient’s oral function and rehabilitation. Placementof implant-supported prosthesis proves useful for rehabilitation of those patients. Objective: Thepresent study reports a case of a patient subjected to high doses of radiotherapy after surgical removal ofa malignant tumor located on the floor of the mouth. Methods: Six implants were installed in the anteriorregion of the mandible and a prosthesis was fabricated according to Brånemark’s protocol. Conclusion: It isreasonable to conclude that osseointegrated implants can be safely employed, provided that special carebe taken with regard to the adverse effects produced by resection and radiotherapy. Improvements inmastication, speech and esthetics promote patient’s social reintegration, thus minimizing discomfort andsuffering, in addition to optimizing therapeutic results and quality of life.

Assessing joint effusion and bone changes of the head of the mandible in MR images of symptomatic patients

The aim of the present study was to investigate the relationship between degenerative bone changes of the head of the mandible and the presence of joint effusion (JE). This study was based on sagittal magnetic resonance imaging (MRI) reports of 148 temporomandibular joints (TMJs) of 74 patients complaining of pain and/or dysfunction in the TMJ area. The mandible heads were surveyed for osteoarthritis characteristics, which were classified as osteophytosis, sclerosis or erosion. The presence of JE was checked whenever high signal intensity was observed in the articular space. The results evidenced the presence of bone changes in 30% of the sample. Osteophytes and erosions were the changes most commonly observed. JE was reported in 10% of TMJs. The results from the statistical tests revealed that bone changes in the head of the mandible are associated with the presence of JE.

Mastigação e deglutição em mulheres jovens com desordem temporomandibular / Chewing and swallowing in young women with temporomandibular disorder

OBJETIVO: Avaliar a mastigação e a deglutição em mulheres com e sem desordem temporomandibular (DTM) e investigar a posição da mandíbula e do osso hioide, por serem estruturas importantes para a realização destas funções. MÉTODOS: Setenta mulheres foram avaliadas quanto à presença de DTM segundo o instrumento Critérios de Diagnóstico para Pesquisa de Desordem Temporomandibular, sendo que 34 delas, com DTM, constituíram o grupo de estudo (GE) e 36 participaram do grupo controle (GC). A avaliação da mastigação e deglutição foi baseada no Protocolo de Avaliação Miofuncional Orofacial com Escores (AMIOFE). As variáveis referentes à posição da mandíbula e osso hioide aferidas pela análise cefalométrica. RESULTADOS: Os indivíduos com DTM apresentaram diferença significativa quanto à postura de língua (p=0,03) e lábios (p=0,04) durante a função de deglutição, bem como a adoção mais frequente de um padrão mastigatório unilateral crônico (p=0,03). Além disso, apresentaram posição mais baixa do osso hioide em relação à mandíbula (p=0,00). CONCLUSÃO: A presença de DTM promoveu maior frequência de alterações miofuncionais orofaciais durante as funções de mastigação e deglutição. A maior distância entre o osso hioide e a mandíbula, bem como a presença da sintomatologia álgica, podem justificar, em parte, os comportamentos atípicos da língua e dos lábios observados no grupo com DTM. A repercussão da DTM sobre as funções alimentares em uma faixa etária jovem explica a importância do diagnóstico e da intervenção terapêutica precoce nestes indivíduos.

PURPOSE: To evaluate chewing and swallowing functions in women with and without temporomandibular disorder (TMD) and investigate the position of the mandible and the hyoid bone as they are important structures in the development of these functions. METHODS: Seventy women were evaluated in relation to TMD diagnosis according to the Research Diagnostic Criteria, among them, 34 composed the study group (SG) with TMD and 36 took part in the control group (CG). Evaluation of the masticatory and swallowing functions was performed according to the Protocol of Orofacial Myofunctional Evaluation with Scores. Mandibular and hyoid bone position variables were measured by cephalometric analysis. RESULTS: TMD subjects showed a significant difference on tongue (p=0.03) and lip (p=0.04) posture during swallowing function, and a more frequent adoption of a chronic unilateral chewing pattern as well (p=0.03). Moreover, they presented a lower position of the hyoid bone in relation to the mandible (p=0,00). Conclusion: TMD presence resulted on a higher frequency of myofunctional alterations during masticatory and swallowing functions. A greater distance from hyoid bone to the mandible in addition with the presence of painful symptom can justify, partly, the atypical behaviors of the tongue and lips observed on TMD group. The TMD repercussion on alimentaires functions in a young age group justifies the importance of an earlier diagnosis and therapeutic intervention in these individuals.

Growth inhibition in rats fed inadequate and incomplete proteins: repercussion on mandibular biomechanics / Growth inhibition in rats fed inadequate and incomplete proteins: repercussion on mandibular biomechanics.

This study describes the effects of feeding growing rats with a diet containing inadequate and incomplete proteins on both the morphological and the biomechanical properties of the mandible. Female rats aged 30 d were fed freely with one of two diets, control (CD, 301 Cal/100g) and experimental (ED, 359 Cal/100g). CD was a standard laboratory diet, while ED was a synthetic diet containing cornflower supplemented with vitamins and minerals. Both diets had the same physical characteristics. Control (C) and experimental (E) animals were divided into 4 groups of 10 animals each. C40 and E40 rats were fed CD and ED, respectively, for 40 d; C105 were fed the CD for 105 d; and E105 were fed the ED for 40 d and then the CD for the remainder of the experimental period (65 d). Mandibular growth was estimated directly on excised and cleaned bones by taking measurements between anatomical points. Mechanical properties of the right hemimandible were estimated by using a 3-point bending test to estimate the structural properties of the bone. Geometric properties of both the entire bone and the cross-section were determined. Bone material properties were calculated from structural and geometric properties. The left hemimandibles were ashed and the ash weight obtained. Rats fed the ED failed to achieve normal body weight gain. Complete catch-up was observed at the end of nutritional rehabilitation. Mandibular weight and length were negatively affected by the ED, as were the cross-sectional area, the mineralized cortical area, and the cross-sectional moment of inertia. All of these parameters showed incomplete catch-up. The structural bone mechanical properties indicative of strength and stiffness were negatively affected. Intrinsic material properties, as assessed by the modulus of elasticity and maximal elastic stress, were within normal values. In summary, the experimental bone was weaker than the control and structurally incompetent. The bone considered was smaller than the control bone, showing a significant reduction in the cross-sectional area and the moment of inertia. However, material properties as well as the ash fraction and degree of mineralization were similar in E and C bones. Therefore, the E bone was weaker than the C bone because of its smaller bone mass, which appears to have been negatively influenced by the ED in relation to its effects on overall body mass.

Emerging applications of an experimental single photon emission computed tomography: an analysis of 16 areas of interest in the pig's model / Aplicaciones emergentes experimentales de la tomografía computarizada por emisión de fotones individuales: un análisis de 16 áreas de interés en el modelo de cerdo

This paper aims to affirm various new applications of single photon emission computed tomography (SPECT) technique by utilizing the pig's models. Evaluation and subsequent analysis of SPECT results was conducted on the jaws of eight experimental pigs with a total of 16 areas of interest. The various reasons for which each experiment was conducted were evaluated and these reasons include: i) validation of a new bone grafting technique for closure of oro-antral communications, ii) comparison of autogeneous bone graft with other bone grafts, iii) sequential confirmation of osteoblastic activity of the sandwich bone regeneration technique with another technique, iv) validation of the use of a new membrane for guided tissue regeneration (GTR), v) validation of the fact that osseointegration is better with beaded implants than with threaded implants, and vi) validation of the fact that GTR is essential for immediate implant practice. The outcome of this evaluation is critically analysed against the background of the substantial clinical evidence where applicable, so as to appreciate the position of SPECT. Following the evaluation of 16 areas of interest in eight experimental pigs, it was shown that experimental SPECT was valuable in the validation of the above reasons. It appears to be a modality that can continuously be utilized to validate and compare situations which would display osteoblastic activities. It is concluded that the bone scintigraphy imaging technique accurately reflects osteoblastic activities and can now be used to validate osseointegration of any implant or bone-grafting system. This can be done in conjunction with histological and histomorphometic analysis and such results obtained from SPECT should be correlated with the histological and histomorphometric analysis if available.

El presente trabajo tiene por objeto dar a conocer varias nuevas aplicaciones de la técnica de la tomografía computarizada por emisión de fotones individuales (inglés SPECT), utilizando modelos de cerdo. Se llevó a cabo una evaluación y el posterior análisis de los resultados de la SPECT en relación con las mandíbulas de ocho cerdos experimentales con un total de 16 áreas de interés. Se evaluaron las varias razones por las que se llevó a cabo cada experimento. Las razones incluyen: i) validación de una nueva técnica de injerto óseo para el cierre de las comunicaciones oroantrales; ii) comparación del injerto óseo autógeno con otros injertos óseos; iii) confirmación secuencial de la actividad osteoblástica de la técnica de regeneración ósea por "sándwich" o membrana inter-posicional con otra técnica; iv) validación del uso de una nueva membrana para la regeneración tisular guiada (RTG); v) validación del hecho que la osteointegración es mejor con implantes porosos que con implantes roscados; y vi) valoración del hecho de que la RTG es esencial para la práctica del implante inmediato. El resultado de esta evaluación se analiza críticamente contra el trasfondo de la evidencia clínica sustancial donde es aplicable, para apreciar la posición de SPECT. Tras la evaluación de 16 áreas de interés en ocho cerdos experimentales, se vio que la SPECT experimental era valiosa para la validación de las razones anteriores. Parece ser una modalidad que puede utilizarse para validar y comparar situaciones que desplegarían actividades osteoblásticas. Se concluye que la gammagrafía ósea refleja las actividades osteoblásticas con precisión, y puede ahora usarse para validar la osteointegración de cualquier implante o sistema de injerto óseo. Esto puede hacerse junto con análisis histológicos y análisis histomorfométicos. Los resultados obtenidos de la tomografía SPECT deben ponerse en correlación con el análisis histológico e histomorfométrico, si estuviese disponible.

Evaluation of acute radiation effects on mandibular movements of patients with head and neck cancer / Avaliação dos efeitos agudos da radioterapia sobre os movimentos mandibulares de pacientes com câncer de cabeça e pescoço

OBJECTIVES: To evaluate radiotherapy effects (RT) on mandibular movements of patients with head and neck cancer (H&NC) and associate them to the variables: functional capacity, radiation field, disease staging, type of feeding, concomitant chemotherapy and total dose of RT. METHODS: Twenty-six patients with H&NC were followed up at the RT service. Physical examination was performed in 3 follow up time points: before the beginning of RT (T0), between 14th and 17th session of RT (T1) and after the last session of RT (T2). The physical examination consisted of the assessment of the following variables: mouth opening without pain (MO), maximum mouth opening (MMO), right lateral excursion (RLE), left lateral excursion (LLE) and protrusion (PR) of the jaw. The feeding type and the Karnofsky Performance Status Scale (KPS) were evaluated in each follow up time point. Data with regards to the tumor lesion and the RT were collected from the patient's clinical notes. RESULTS: There was a statistical significant reduction in the values of MO (p=0.006), MMO (p=0.001), LLE (p=0.006) and KPS (p=0.001). There was significant a statistical association among the reduction in KPS and decreased measure of MO (r=0.390, p=0.048) and MMO (r=0.435, p=0.026). The mouth and oropharynx radiation fields when combined showed a significant reduction for both the measure of MO (p=0.005) and for MMO (p=0.004). Patients who used nasoenteric tube feeding (NTF) had greater reduction in the measurement of MMO (p=0.031). The remaining variables showed no statistically significant difference. CONCLUSION: Patients with H&NC present reduction of the measures of MO and MMO during the RT, especially if they present reduced functional capacity, have radiation in the mouth and oropharynx fields and used NTF.

OBJETIVOS: Avaliar os efeitos da radioterapia (RT) sobre os movimentos mandibulares de pacientes com câncer de cabeça e pescoço (CCeP) e associá-los às variáveis: capacidade funcional, campo de radiação, estadiamento da doença, tipo de alimentação, quimioterapia concomitante e dose total de RT. MÉTODOS: Vinte e seis pacientes com CCeP foram acompanhados em um serviço de RT. O exame físico ocorreu em três momentos: antes do início da RT (M0), entre a 14º e 17º sessão (M1) e após a última sessão de RT (M2) para verificação de variáveis, como: abertura bucal sem dor (AB), abertura bucal máxima (ABm), excursão lateral direita (EXd), excursão lateral esquerda (EXe) e protrusão (PR) da mandíbula. O tipo de alimentação e a Escala de Karnofsky (EK) foram reavaliados em cada momento. Dados a respeito da lesão tumoral e RT foram coletados do prontuário do paciente. RESULTADOS: Houve redução significativa nos valores de AB (p=0,006), ABm (p=0,001), EXe (p=0,006) e EK (p=0,001). Houve associação estatisticamente significativa entre a redução na EK e a diminuição de AB (r=0,390; p=0,048) e de ABm (r=0,435; p=0,026). Os campos de radiação da boca e orofaringe, quando agrupados, apresentaram redução significativa tanto para a medida de AB (p=0,005) quanto para ABm (p=0,004). Os pacientes que utilizaram sonda nasoentérica (SNE) apresentaram maior redução da medida de ABm (p=0,031). As demais variáveis não apresentaram diferença estatisticamente significativa. CONCLUSÃO: Os pacientes com CCeP apresentam redução das medidas de AB e ABm no decorrer da RT, principalmente se apresentarem redução da capacidade funcional, tiverem irradiação para os campos da boca e orofaringe e fizerem uso de SNE.

The effect of implant design on the stress distribution in a three-unit implant-supported distal cantilever fixed partial denture: A three-dimensional finite-element analysis.

Context: Implant design influences the stress distribution in an implant-supported distal cantilever fixed partial denture and supporting bone tissue. Aim: The purpose of this study was to investigate the effect of implant design on the stress distribution in the framework, implant, and surrounding bone, using a three-dimensional finite-element analysis. Materials and Methods: A three-dimensional finite-element model of a mandibular section of bone with implants placed in the first and second premolar region was created to support a distal cantilever fixed partial denture. A one-piece and two-piece implant and its suprastructure were simulated into wire frame models using Pro engineer (Pro E) program. Four models were created in this study. Results: Comparative analysis of all models showed that the maximum stress overall was in the cervical portion of the secondary abutment. When used in combination, the maximum stress was when the two-piece implant was used as secondary abutment. The one-piece implant showed less stress compared to its counterpart when used as secondary abutment. The maximum stress distribution in the bone was around the neck region of the secondary implant. Conclusion: Within the limitations of this study, it can be concluded that stress distribution is better in a one-piece implant design when compared with the two-piece implant design, with stress concentration being more at the junction of the abutment and the implant fixture in the two-piece implant. When implants are used as abutments (either primary or secondary), irrespective of their position and design, the secondary implant shows the maximum amount of stresses.

Trismus as a first presenting complaint in a case of myasthenia gravis.

The initial presentation of myasthenia gravis as trismus is very rare and no previous reports have been found in the literature. A 35-year-old male presented to the outpatient unit of our department with inability to clench well and to open his mouth. Physical examination revealed that he had clinical findings consistent with the signs and symptoms of myasthenia gravis. He was immediately referred to a neurologist, who confirmed that he was in an advanced stage of myasthenia gravis with severe deficit to his respiratory muscles and he was promptly treated. He is presently on a maintenance drug therapy. To our knowledge, this is the first reported case of myasthenia gravis whose initial presentation was trismus. This case presents a rare but important diagnosis that should be added to the differential diagnosis of trismus.

Mandibular range of motion in patients with idiopathic peripheral facial palsy / Amplitude mandibular em pacientes com paralisia facial periférica idiopática

Regarding orofacial motor assessment in facial paralysis, quantitative measurements of the face are being used to establish diagnosis, prognosis and treatment planning. AIM: To assess the prevalence of changes in mandibular range of motion in individuals with peripheral facial paralysis. MATERIALS AND METHODS: Prospective study. We had 56 volunteers, divided in two groups: G1 made up of 28 individuals with idiopathic facial paralysis (6 males and 22 females); 14 with manifestations on the right side of the face and 14 on the left side; time of onset varied between 6-12 months; G2 with 28 healthy individuals paired by age and gender to G1. In order to assess mandibular range of motion, a digital caliper was used. The following measurements were made: 1) middle line; 2) maximum oral opening; 3) lateralization to the right; 4) lateralization to the left; 5) protrusion; 6) horizontal overlap. RESULTS: Statistically significant differences between the groups were observed for maximum oral opening, lateralization to the left and protrusion. G1 presented smaller measurement values than G2. CONCLUSION: Patients with facial paralysis present significant reduction of mandibular range of motion. The results support the suggestion of incorporating functional evaluation of the temporomandibular joint to the existing facial paralysis clinical assessment protocols.

Na atuação fonoaudiológica na paralisia facial, medidas quantitativas da face têm sido cada vez mais utilizadas para avaliação, diagnóstico, prognóstico e planejamento terapêutico. OBJETIVO: Avaliar a prevalência de alterações de amplitude mandibular na paralisia facial periférica de origem. MATERIAL E MÉTODO: Estudo prospectivo. Cinquenta e seis indivíduos foram divididos em dois grupos: G1 com 28 pacientes com paralisia facial idiopática (6 homens e 22 mulheres), 14 com comprometimento à direita e 14 à esquerda e tempo de duração da paralisia entre 6 e 12 meses; G2 composto por 28 indivíduos saudáveis pareados por idade e sexo ao G1. Para avaliação da amplitude mandibular, foi utilizado um paquímetro digital, sendo realizadas as seguintes medidas: 1) linha média; 2) abertura oral máxima; 3) lateralização da mandíbula para direita; 4) lateralização da mandíbula para esquerda; 5) protrusão mandibular; 6) trespasse horizontal. RESULTADOS: Foi observada diferença média significante entre os grupos para a abertura oral máxima, lateralização para esquerda e protrusão mandibular. G1 apresentou resultados menores que G2. CONCLUSÃO: Pacientes acometidos por paralisia facial apresentam redução significante na amplitude mandibular. Os resultados apoiam a sugestão de que sejam incorporadas às avaliações clínicas da paralisia facial as provas de funcionalidade da articulação têmporo-mandibular.

Bone mineral density and bone strength from the mandible of chronically protein restricted rats

The present investigation was performed to assess the biomechanical repercussion of protein malnutrition imposed on rats between the 26th and 135th days of postnatal life on the mandible, which is not a weight-bearing bone but supports the loads related to the masticatory activity. Female Wistar rats aged 26 d (n=14) were placed on either a 4%-protein diet (ICN 960254, P4 group) or a 20%-protein diet (ICN 960260, P20 group) and killed 111 d later. Both body weight and length were recorded regularly. The mandibles were dissected and cleaned of adhering soft tissue. Mandibular growth was estimated directly by taking measurements between anatomical points. Areal Bone Mineral Density (BMD) was estimated using a bone densitometer (LUNAR DPX-L). Mechanical properties of the right hemimandible were determined using a three-point bending mechanical test to obtain the load/deformation curve and estimate the structural properties of the bone. Results were summarized as means ± SD. Comparisons between parameters were performed by Student's t test. A 75% reduction in body weight and a 32% reduction in body length were observed in P4 rats. Like body size, mandibular weight, length, height and area (index of mandibular size) were negatively affected by P4 diet, as was the posterior part of the bone (posterior to molar III). The anterior part (alveolar and incisor alveolar process) was not affected by age or diet. The "load capacity" extrinsic properties of the mandible (load fracture, stiffness, yielding point) were between 43% and 64% of control value in protein restricted rats. BMD was similar in both groups of animals. Conclusion: 1) Chronic protein malnutrition imposed on rats from infancy to early adulthood reduces the growth of the posterior part of the mandible without inducing changes in the anterior part, which produces some deformation of the bone in relation to age-matched rats; and 2) the significant reduction of strength and stiffness of the mandible seem to be the result of an induced loss of gain in bone structural properties as a consequence of a correlative loss of gain in both growth and mass, yet not in bone material properties.

La investigación presente fue diseñada con el objeto de evaluar la repercusión biomecánica de la malnutrición proteica impuesta a ratas entre los días 26º y 135º de edad sobre la mandíbula (M), hueso que no soporta carga relacionada con el peso corporal sino con las fuerzas masticatorias. Ratas Wistar hembras de 26 d de edad (n=14) fueron alimentadas con dietas conteniendo 4% (grupo P4) (ICN 960254) o 20% (grupo P20) (ICN 960260) de caseína y sacrificadas 111 d después. Peso y longitud corporales fueron registrados regularmente. Las mandíbulas fueron disecadas y liberadas de tejido blando. Se realizaron mediciones entre diversos puntos anatómicos para estimar la morfometría del hueso. La Densidad Mineral Osea (DMO) fue determinada en un densitómetro LUNAR DPX-L. La M derecha de cada animal fue sometida al test de flexión a 3 puntos para obtener la curva carga/deformación y estimar las propiedades estructurales del hueso mandibular. Los resultados (X±DS) fueron analizados estadísticamente mediante test t de Student. El peso y la longitud corporales fueron menores en el grupo P4 que en el P20 (-75% y -32%, respectivamente). Longitud de la base, altura y área mandibular (índice del tamaño de M) fueron afectados negativamente por la dieta P4, lo mismo que la porción posterior de M (posterior al molar III). La porción anterior (procesos alveolar e incisivo) no fueron afectadas por dieta o edad. Todas las propiedades biomecánicas de M (carga de fractura, resistencia en fase elástica, límite elástico) fueron 43-64% menores en grupo P4 que en grupo P20. El valor de DMO fue similar en ambos grupos. CONCLUSION: 1) La malnutrición proteica crónica impuesta a ratas desde la infancia hasta la adultez reduce el crecimiento de la porción posterior de la mandíbula sin inducir cambios en su porción anterior, lo que produce una cierta deformación del hueso en comparación con animales de la misma edad; y 2) la importante disminución de la resistencia a fractura y de la rigidez durante el período elástico sería el resultado de una reducción de ganancia de las propiedades estructurales óseas como consecuencia de una reducción correlativa de ganancia de masa ósea, con mantenimiento de la normalidad de las propiedades óseas intrínsecas.

Validation of the multimedia version of the RDC/TMD axis II questionnaire in Portuguese

OBJECTIVE: The aim of the study was to validate the multimedia version of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II Questionnaire in Portuguese language. MATERIAL AND METHODS: The sample comprised 30 patients with signs and symptoms of temporomandibular disorders (TMD), evaluated at the Orofacial Pain Control Center of the Dental School of the University of Pernambuco, Brazil, between April and June 2006. Data collection was performed using the following instruments: Simplifed Anamnestic Index (SAI) and RDC/TMD Axis II written version and multimedia version. The validation process consisted of analyzing the internal consistency of the scales. Concurrent and convergent validity were evaluated by the Spearman's rank correlation. In addition, test and analysis of reproducibility by the Kappa weighted statistical test and Spearman's rank correlation test were performed. RESULTS: The multimedia version of the RDC/TMD Axis II questionnaire in Portuguese was considered consistent (Crombrach alpha = 0.94), reproducible (Spearman 0.670 to 0.913, p<0.01) and valid (p<0.01). CONCLUSION: The questionnaire showed valid and reproducible results, and represents an instrument of practical application in epidemiological studies of TMD in the Brazilian population.

Fibroma ossificante juvenil localizado em mandíbula: relato de caso e breve revisão da literatura / Juvenile ossifying fibroma of the mandible: case report and brief review of the literature

O fibroma ossificante juvenil (FOJ) é designado como um neoplasma fibro-ósseo benigno, observado em indivíduos jovens. São descritas duas variantes clínico-patológicas, denominadas de fibroma ossificante juvenil trabecular (FOJtr) e fibroma ossificante juvenil psamomatoide (FOJps). Essas lesões, quando acometem ossos gnáticos, localizam-se preferencialmente em maxila, sendo incomum a apresentação de lesões em mandíbula. Histologicamente, essa lesão caracteriza-se por estroma fibroso densamente celularizado, exibindo depósitos de osteoide desprovido de margem osteoblástica, associados a trabéculas de osso imaturo mais típicas, no caso de FOJtr, e ocasionais estruturas psamomatoides, evidenciadas em FOJps. O presente trabalho relata um caso de FOJ de ampla extensão, localizado na mandíbula de um menino de 11 anos bem como revisa os principais achados na literatura com relação à etiopatogênese e a aspectos clínico-patológico-terapêuticos.

Juvenile ossifying fibroma (JOF) is a benign fibro-osseous neoplasm. Two distinct clinicopathologic variants, namely, juvenile trabecular ossifying fibroma (JTOF) and juvenile psammomatoid ossifying fibroma (JPOF) are described. When located in the gnathic bones, these lesions show a predilection for the maxilla, their occurrence in the mandible being uncommon. Histologically, the JOF is characterized by a cell-rich fibrous stroma, containing bands of osteoid without osteoblastic lining, together with more typical immature woven bone trabeculae in JTOF, and occasional psammomatoid structures in JPOF. The present paper reports a case of an 11-year-old boy with a large mandibular JOF, and reviews the main aspects described in the literature related to the etiopathogenesis and clinicopathologic and therapeutic aspects of JOF.

Finite element analysis of the mechanical behavior of a partially edentulous mandible as a function of cancellous bone density / Análise por elementos finitos do comportamento mecânico de uma mandíbula humana parcialmente edêntula em função da densidade óssea trabecular

Purpose: To present a methodological procedure to obtain the geometric and discrete models of a human mandible for numerical simulation of the biomechanical behavior of a partially edentulous mandible as a function of cancellous bone density. Methods: A 3D finite element method was used to assess the model of a partially edentulous mandible, Kennedy Class I, with dental implants placed at the region of teeth 33 and 43. The geometric solid model was built from CT-scan images and prototyping. In the discrete model a parametric analysis was performed to analyze the influence of cancellous bone density (25 %, 50 %, 75 %) on the development of mandibular stress and strain during simulation of masticatory forces in the anterior region. Results: Maximum von Mises stress and equivalent strain values in cancellous bone were found close to the loading area (masticatory forces). The peak stress and strain values occurred in the mandibular anterior region, and for the same masticatory force the equivalent stresses increased with bone density. Conclusion: The results suggest that the stresses and strains developed in the mandibular model were affected by cancellous bone density during the simulation of masticatory activity.

Objetivo: Apresentar uma metodologia para modelamento geométrico de uma mandíbula humana e obtenção de um modelo discreto para simular numericamente o comportamento biomecânico de uma mandíbula parcialmente edêntula em função de diferentes densidades do osso trabecular. Metodologia: Utilizou-se o método de elementos finitos 3D para realizar um estudo numérico sobre um modelo de mandíbula humana, desdentada parcial tipo Classe I de Kennedy, com implantes nas regiões dos dentes 33 e 43. O modelo sólido geométrico foi determinado por tomografia computorizada e prototipagem. No modelo discretizado foi realizada uma análise paramétrica para verificar a influência da densidade óssea do osso trabecular (25 %, 50 %, 75 %) no desenvolvimento de tensões e deformações da mandíbula durante a aplicação de forças mastigatórias na região anterior. Resultados: As tensões máximas de von Mises e deformações equivalentes no osso trabecular foram desenvolvidas próximo às regiões de aplicação das forças de mordida. Os picos de valores de tensões/deformações localizaram-se na região anterior da mandíbula, sendo que, para o mesmo valor de esforço de mordida, as tensões equivalentes aumentaram com a densidade óssea. Conclusão: Os resultados sugerem que as tensões e deformações desenvolvidas no modelo mandibular testado foram afetadas pelo grau de densidade do osso trabecular durante simulação de atividade mastigatória.