Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography.

There are many limitations to image acquisition, using conventional radiography, of the temporomandibular joint (TMJ) region. The Computed Tomography (CT) scan is a better option, due to its higher accuracy, for purposes of diagnosis, surgical planning and treatment of bone injuries. The aim of the present study was to analyze two protocols of cone beam computed tomography for the evaluation of simulated mandibular condyle bone lesions. Spherical lesions were simulated in 30 dry mandibular condyles, using dentist drills and drill bits sizes 1, 3 and 6. Each of the mandibular condyles was submitted to cone beam computed tomography (CBCT) using two protocols: 1) axial, coronal and sagittal multiplanar reconstruction (MPR); and 2) sagittal plus coronal slices throughout the longitudinal axis of the mandibular condyles. For these protocols, 2 observers analyzed the CBCT images independently, regarding the presence or not of injuries. Only one of the observers, however, performed on 2 different occasions. The results were compared to the gold standard, evaluating the percentage of agreement, degree of accuracy of CBCT protocols and observers' examination. The z test was used for the statistical analysis. The results showed there were no statistically significant differences between the 2 protocols. There was greater difficulty in the assessment of small-size simulated lesions (drill # 1). From the results of this study, it can be concluded that CBCT is an accurate tool for analyzing mandibular condyle bone lesions, with the MPR protocol showing slightly better results than the sagittal plus coronal slices throughout the longitudinal axis.

Assessment of simulated mandibular condyle bone lesions by cone beam computed tomography

There are many limitations to image acquisition, using conventional radiography, of the temporomandibular joint (TMJ) region. The Computed Tomography (CT) scan is a better option, due to its higher accuracy, for purposes of diagnosis, surgical planning and treatment of bone injuries. The aim of the present study was to analyze two protocols of cone beam computed tomography for the evaluation of simulated mandibular condyle bone lesions. Spherical lesions were simulated in 30 dry mandibular condyles, using dentist drills and drill bits sizes 1, 3 and 6. Each of the mandibular condyles was submitted to cone beam computed tomography (CBCT) using two protocols: 1) axial, coronal and sagittal multiplanar reconstruction (MPR); and 2) sagittal plus coronal slices throughout the longitudinal axis of the mandibular condyles. For these protocols, 2 observers analyzed the CBCT images independently, regarding the presence or not of injuries. Only one of the observers, however, performed on 2 different occasions. The results were compared to the gold standard, evaluating the percentage of agreement, degree of accuracy of CBCT protocols and observers' examination. The z test was used for the statistical analysis. The results showed there were no statistically significant differences between the 2 protocols. There was greater difficulty in the assessment of small-size simulated lesions (drill # 1). From the results of this study, it can be concluded that CBCT is an accurate tool for analyzing mandibular condyle bone lesions, with the MPR protocol showing slightly better results than the sagittal plus coronal slices throughout the longitudinal axis.

Avaliação da densidade ótica periimplantar cervical em implantes com função oclusal imediata em maxila / Evaluation of the optical density perimplantar cervical in implants with immediate occlusion function

Foram avaliadas a salterações da densidade ótica do osso alveolar periimplantar cervical por meio de radiografias periapicais digitalizadas, de 60 implantes localizados na maxila e submetidos à função oclusal imediata. Os pacientes foram acompanhados clinicamente e por meio de análise da freqüencia da ressonância. Foram realizadas radiografias periapicais obtidas na instalação da prótese, após seis meses e após 12 mases, as quais foram então analisadas digitalmente. os resultados mostraram que ocorreu variação percentual da densidade ótica na área de interesse nos primeiros seis meses, com diminuição de aproximadamente 5% para o lado direito e de aproximadamente 6% para o lado esquerdo e após 12 meses a diminuição da densidade óssea estabilizou-se. Os dados obtidos foram compatíveis coma análise da freqüência de ressonância e exame clínico dos implantes e demonstraram o sucesso dos implantes osteointegrados com função imediata na maxila.

Avaliação cefalométrica radiográfica da posição craniocervical de pacientes orientados em posição natural da cabeça pré e pós-expansão rápida da maxila / Cephalometric radiographic evaluation of the craniocervical position of patients oriented in natural head position before and after the rapid maxillary expansion

O objetivo deste estudo foi avaliar a eventual alteração na posição craniocervical de pacientes orientados na Posição Natural da Cabeça (PNC), após o procedimento de expansão rápida da maxila (ERM). Utilizaram-se telerradiografias em norma lateral, selecionadas do acervo de documentação da Clínica de Ortodontia Preventiva da Faculdade de Odontologia da Universidade de São Paulo, de 20 pacientes, com idades entre 5 e 11 anos (média de 9,0 anos), sendo 7 do gênero masculino e 13 do feminino, obtidas no início do tratamento e imediatamente após a fase ativa da expansão da maxila. Os pacientes eram portadores de atresia da maxila e foram tratados com aparelho disjuntor tipo Bierdeman modificado. A partir dos cefalogramas pré e pós-ERM foram obtidas as grandezas angulares craniovertical (SN.VER), craniocervical (OPT.SN e CVT.SN), cervicohorizontal (OPT.HOR, CVT.HOR) e o ângulo da curvatura cervical (OPT.CVT). Após análise estatística e interpretação dos resultados obtidos concluímos que a posição da cabeça não apresentou alteração estatisticamente significativa. Não foram observadas diferenças estatisticamente significativas entre os gêneros quando comparadas as fases pré e pós-ERM para as grandezas estudadas. O método de obtenção de telerradiografias laterais em Orientação Natural da Cabeça mostrou-se confiável e reproduzível na amostra estudada, mesmo na presença de intervenção ortodôntica-ortopédica entre as séries de radiografias.