Influence of mandibular positioning on the accuracy and reliability of linear measurements on cone beam CT using different voxels and two software programs / Influência do posicionamento mandibular na acurácia e confiabilidade de medidas lineares em tomografia computadorizada de feixe cônico utilizando diferentes voxels e dois softwares

Objetivo: este estudo avaliou a acurácia e confiabilidadedas medidas lineares em exames detomografia computadorizada de feixe cônico(TCFC), em dois softwares, utilizando diferentesvoxels e variando o posicionamento da mandíbula.Material e Métodos: 10 imagens de TCFC demandíbulas humanas com 25 pontos foram obtidas,usando diferentes protocolos de aquisição(0.250, 0.300, 0.400-mm voxels) e orientações damandíbula (centralizada, rotacionada 10° lateralmentepara direita e esquerda, inclinada 10° para cima e para baixo); 14 medidas foram realizadasnas reconstruções multiplanares nos softwares XoranCate OsiriX. Os achados foram comparadoscom as medidas físicas através de um paquímetrodigital. O teste ANOVA e o coeficiente de correlaçãoforam utilizados com p < 0,05. Resultados:não houve diferença estatisticamente significantequando as medidas foram comparadas em aquisiçõescom diferentes tamanhos de voxels emambos os softwares. A posição da mandíbula nãoinfluenciou nas medidas. Nenhuma diferença foiencontrada quando os valores foram comparadosentre os softwares e o paquímetro digital. Conclusão:as medidas lineares em ambos os softwaresforam confiáveis e acurados comparados a mensuraçãofísica em todos os protocolos. A acuráciae a confiabilidade das mensurações não influenciaramde acordo com as variações de posicionamentoda mandíbula.(AU)

Objective: this study evaluated the accuracy and reliability of linear measurements on cone beam CT (CBCT) scans in two software programs, using different voxels and varying mandible positioning. Material and methods: CBCT images of 10 human mandibles with 25 markers were obtained using different acquisition protocols (0.250, 0.300, 0.400-mm voxels) and mandible orientations (centered, rotated 10° laterally to right and left, tilted 10 up and down); fourteen measurements were carried out on the multiplanar reconstructions in XoranCat and OsiriX Lite software programs. The findings were compared to physical measurements using a digital caliper. ANOVA and correlation coefficient tests were used, at α = 0.05. Results: there was no statistically significant difference when the measurements were compared in acquisitions with different voxel sizes analysed in both software programs. Mandibular positioning changes did not influence the measurements. No differences were found when the values were compared between the software programs and the digital caliper. Conclusion: linear measurements in both programs were reliable and accurate compared with physical measurements when using all acquisition protocols. The accuracy and reliability of the measurements were not influenced by variations in the mandible positioning.(AU)

Cone-beam computed tomographic study of the persistent foramen tympanicum according to age, sex, and skeletal patterns.

This cross-sectional study evaluated the influence of prevalence, laterality and diameter of persistent foramen tympanicum (PFT) in cone beam computed tomographic (CBCT) scans of adult patients with different sagittal skeletal patterns, sex and age. CBCT of 510 patients were assessed for the presence of PFT. Skeletal pattern, age and sex of the affected patients were recorded, as well as laterality and diameter of PFT. Differences were tested using the one-way ANOVA, chi squared and paired-t tests, at α=5%. A total of 49 (9.7%) patients presented with PFT; 36 (73.5%) were women (p<0.01) aging from 31-50 years (p>0.05), with Class III skeletal pattern (p>0.05). The unilateral/bilateral ratio was 3.9:1 (p<0.01). No correlation was found between the PFT diameters with sex and age, but differences were found between the classes, with the largest diameters in Class II individuals (p=0.046). The prevalence of PFT in CBCT scans was 9.7%, with women being more affected, with unilateral defects in most cases. Skeletal patterns did not have significant effects on PFT prevalence, although PFT diameter varied among classes, with higher measures in Class II individuals.

Imaginology Tridimensional Study of Temporomandibular Joint Osseous Components According to Sagittal Skeletal Relationship, Sex, and Age.

OBJECTIVE: To assess the temporomandibular joint (TMJ) osseous components morphology and the condyle position in patients with different sagittal skeletal relationships, sex, and age, using cone-beam computed tomography (CBCT). METHODS: The CBCT images of 180 asymptomatic patients (60 class I, 60 class II, and 60 class III) were assessed retrospectively. Groups were also divided according to age (<40 years, n = 90; ≥40 years, n = 90) and sex (male, n = 90; female, n = 90). Right- and left-sided TMJ spaces, articular eminence inclination (AEI) and height (AEH), thickness of the roof of the glenoid fossa (TRGF) and the anteroposterior position of the condyle in glenoid fossa were evaluated. Differences were tested using the analysis of variance, Tukey and t-tests (P < 0.05). RESULTS: For condylar position, no differences were found between sex and age groups, but spatial differences existed among skeletal classes. Significant differences were found between the right and left angular position in patients with malocclusion. Class II individuals presented lower anterior articular spaces. The condyle-glenoid fossa relationship presented a moderate correlation of bilaterality. The AEI and AEH were significant lower in class III individuals and class I patients presented the lowest values for TRGF. The values of AEH, TRGF and of all joint spaces of males were higher. In individuals over the age of 40 years, the AEI and AEH measurements were significant greater. CONCLUSION: Sagittal skeletal relationships have a significant effect on condyle position, AEI, and AEH. The eminence inclination and height and TRGF are influenced by sex and age.

Cone beam computed tomography study of osteoarthritic alterations in the osseous components of temporomandibular joints in asymptomatic patients according to skeletal pattern, gender, and age.

OBJECTIVE: The aim of this study was to evaluate the prevalence of osteoarthritic alterations in the osseous components of the temporomandibular joint (TMJ) in asymptomatic patients with different skeletal patterns, gender, and age groups with cone beam computed tomography (CBCT) images. STUDY DESIGN: CBCT images of 213 asymptomatic patients were assessed for the presence of any degenerative changes in the condyle and fossa/eminence complex. Each TMJ was evaluated separately and was classified as normal, indeterminate for osteoarthritis, or affected by osteoarthritis. Differences were tested by using the χ2 and Fisher's exact tests (P < .05). RESULTS: In total, 52.3% of the joints presented some visible alteration in the osseous components. Abnormalities were detected in 32.6% of the condyles and 31.5% of the articular fossae/eminences, and flattening was the most prevalent alteration in all classes. There was no statistically significant difference in the prevalence of alterations in either the condyle or the articular fossa/eminence among the skeletal groups for the entire sample or for the gender and age subsets. CONCLUSIONS: There are no differences in degenerative TMJ changes in patients with or without skeletal jaw discrepancies. No differences were found when gender and age were considered.

Análise do perfil facial esquelético e de tecidos moles pré e pós-cirurgia ortognática em pacientes Classe II e III, e sua relação com a proporção áurea / Analysis of the skeletal and soft-tissue profiles pre and post orthognathic surgery in Class II and III patients and its relation with the golden proportion

Introdução: A proporção áurea, representada pela razão matemática 1:1.618, tem sido investigada na especialidade Ortodontia e no procedimento de Cirurgia Ortognática, a fim de ser estabelecida como um guia de sucesso clínico relacionado à estética facial. Objetivo: Verificar a estética dos perfis faciais de pacientes Classes II e III de Angle, antes e após tratamento ortodôntico-cirúrgico, além de correlacionar 13 razões dentoesqueléticas e cinco razões de tecidos moles à proporção áurea. Material e método: Um total de 94 radiografias cefalométricas laterais foram analisadas, em que 13 razões dentoesqueléticas e cinco razões em tecidos moles foram medidas e comparadas ao número áureo. Adicionalmente, uma análise subjetiva da estética facial pré e pós-tratamento foi realizada por 270 examinadores. Resultado: As razões dentoesqueléticas 1, 3, 6, 7, 8 e 9 aproximaram-se do número áureo após a cirurgia ortognática, nos pacientes Classe III. Para o perfil mole, apenas a razão 4 se aproximou ao número áureo, em ambos os pacientes Classe II e III. Em relação à avaliação subjetiva da estética, 91,49% dos perfis faciais foram considerados mais harmônicos após o tratamento. Conclusão: Frente à metodologia usada, pode-se concluir que a proporção áurea exerce pouca influência na avaliação da estética facial, não servindo como um guia para o planejamento e o tratamento ortodôntico-ortognático.

Introduction: The golden proportion, represented by the mathematical ratio 1:1.618, has been investigated in Orthodontics and orthognathic surgery in order to be established as a guide to clinical success related to facial aesthetics. Objective: To verify the facial aesthetics of patients with Angle Class II and III deformities pre and post orthodontic-surgical treatment, and to analyze if 13 dental-skeletal patters (ratios) and 5 soft tissue ratios moved closer to or further away from the golden proportion after the orthognathic surgery. Material and method: A total of 94 lateral cephalometric radiographs, in which 13 dental-skeletal ratios and 5 soft tissue ratios were measured and compared to the golden number. In addition, 270 examiners performed a subjective analysis of facial esthetics before and after treatment. Result: Dental-skeletal ratios 1, 3, 6, 7, 8 and 9 moved closer to the golden number after orthognathic surgery in Class III patients. For the soft tissue profile, only ratio 4 moved closer to the golden number in both Class II and III patients. Regarding the subjective evaluation of facial aesthetics, 91.49% of the facial profiles were considered more harmonic after treatment. Conclusion: Considering the methodology, it may be concluded that the golden proportion had little effect on the facial aesthetics evaluation and should not work as a guide for orthodontic-orthognathic planning and treatment.