Quantitative and qualitative comparisons of pulp cavity volumes produced by cone beam computed tomography and micro-computed tomography through semiautomatic segmentation: An ex vivo investigation.

OBJECTIVE: The aim of this study was to measure the volume and visually assess 3-dimensional (3D) virtual models of pulp cavities obtained through semiautomatic segmentation on images from 6 cone beam computed tomography (CBCT) units compared with the reference standard of micro-CT. STUDY DESIGN: Fifteen mandibular premolar teeth were scanned with 6 CBCT units: Prexion 3D Elite, i-CAT Next Generation, NewTom 5G, Cranex 3D, 3Shape X1, and Orthophos SL 3D, using the smallest available field of view and highest resolution settings. Pulp cavity volumes were quantitatively assessed by 2 calibrated examiners. The volumes from each CBCT unit were compared with micro-CT. Qualitative assessment of the 3D reconstructions was also performed. Repeated-measures analysis of variance and the Friedman test compared the CBCT reconstructions to micro-CT. Intra- and interexaminer agreements were calculated with the intraclass correlation coefficient and kappa statistic. RESULTS: The CBCT-based volumes were all significantly larger than micro-CT (P ≤ .0061). Prexion, X1, and Orthophos provided the segmentations that most closely resembled the reference standard. Intra- and interexaminer agreements ranged from good to excellent for quantitative measurements. Interexaminer agreement for qualitative evaluation was substantial. CONCLUSIONS: Semiautomatic segmentation of CBCT images is a feasible method to produce virtual 3D models of the pulp cavity. Prexion, X1, and Orthophos were the CBCT units that resulted in 3D reconstructions most similar to the reference standard.

Lingual Lateral Canal Mimicking Mandible Fracture.

Lingual lateral canal is a rare variation in the trajectory of the mandibular canal, and is usually detected as an incidental finding on radiographic exams, especially on cone-beam computed tomography. Due to its radiographic characteristics, this anatomical variation might be confused with a mandible fracture. Therefore, the knowledge of its presence is essential not only to differentiate it from a fracture, but also for the success of surgical procedures performed in the mandible, making it easier to avoid clinical complications such as swelling, bruising, bleeding, and neurovascular disorders. This report shows the case of a lingual lateral canal mimicking a fracture on the mandibular body.

Can Mental Index be used on CBCT images to determine sexual dimorphism? / O Índice Mentual aplicado em imagens de TCFC pode ser utilizado para determinação do Dimorfismo Sexual?

ABSTRACT Objective: Radiomorphometric indices (RI) vary according to gender and age. The objective of this study was to assess bone quality in men and women, using tomographic images Methods: A total of 78 Cone Beam Computed Tomography (CBCT) images of female and male patients were analyzed. The images were obtained from LAPI-FOUSP database, São Paulo, Brazil, and the Mental Index, which is a quantitative index, was evaluated on those images. The images were divided into 2 groups: Group M - Men and Group W - Women and evaluated by one examiner in two different times (T1 and T2). The data was submitted to a statistical analysis with a 95% level of significance (p <0.05) Results: The ICC tests showed an average to good intra-examiner agreement. The age averages were: 48.46 ± 15.3 for group W and 53.87 ± 13.09 for group M. On the MI evaluation, statistically significant differences were observed between the two groups Conclusion: We concluded that MI can be used to determine sexual dimorphism, once the thickness of the mandible cortex in women is smaller than the thickness found in men.

RESUMO Objetivo: Avaliar o dimorfismo sexual, por meio da aplicação de IR em imagens tomográficas. Métodos: Foram analisados 78 exames de tomografia computadorizada de feixe cônico (TCFC), de pacientes do sexo feminino e masculino. As imagens foram obtidas do banco de dados do LAPI-FOUSP, São Paulo, Brasil, e por meio delas o Índice Mentual, que é um IR quantitativo, foi avaliado. As imagens foram divididas em 2 grupos: Grupo M - Homens e Grupo W - Mulheres e avaliadas por um examinador em dois tempos diferentes (T1 e T2). Os dados foram submetidos a análise estatística com nível de significância de 95% (p<0,05). Resultados: O teste ICC mostrou uma concordância intra-examinador média a boa. As médias de idade foram: 48,46±15,3 para o grupo M e 53,87±13,09 para o grupo H. Na avaliação do IM, foram observadas diferenças estatisticamente significantes entre os dois grupos. Conclusão: Concluímos que o Índice Mentual pode ser utilizado para determinar o dimorfismo sexual, uma vez que a espessura da cortical da mandíbula nas mulheres é menor que a espessura encontrada nos homens.