Aim: To determine the prevalence and classification of bifid mandibular canals using cone beam computed tomography (CBCT). Methods: The sample comprised 300 CBCT scans obtained from the Radiology and Imaging Department database at São Leopoldo Mandic Dental School, Campinas, SP, Brazil. All images were performed on Classic I-Cat® CBCT scanner, with standardized voxel at 0.25 mm and 13 cm FOV (field of view). From an axial slice (0.25 mm) a guiding plane was drawn along the alveolar ridge in order to obtain a cross-section. Results: Among 300 patients, 188 (62.7%) were female and 112 (37.3%) were male, aged between 13 to 87 years. Changes in the mandibular canal were observed in 90 patients, 30.0% of the sample, 51 women (56.7%) and 39 men (43.3%). Regarding affected sides, 32.2% were on the right and 24.5% on the left, with 43.3% bilateral cases. Conclusions: According to the results obtained in this study, a prevalence of 30% of bifid mandibular canals was found, with the most prevalent types classified as B (mesial direction) and bilateral.

ResumoIntrodução: O conhecimento da morfologia normal da mandíbula humana e suas possíveis variações anatômicas, que ocorrem, são de fundamental importância na prática odontológica, especialmente nas áreas da cirurgia e implantodontia. A região retromolar é delimitada pela margem anterior do ramo da mandibular, crista temporal e face distal do último molar inferior. Nessa área pode ser observado o canal retromolar que pode emergir pelo forame retromolar. Objetivo: O presente estudo objetiva avaliar a ocorrência de canais retromolares em exames de tomografia computadorizada de feixe cônico e relaciona-la com suas possíveis repercussões clínicas. Material e método: Foram selecionadas 300 imagens de TCFC provenientes do Departamento de Radiologia da Faculdade São Leopoldo Mandic. O presente estudo foi do tipo observacional descritivo e todas as imagens foram processadas e trabalhadas no software XoranCat  do próprio equipamento. Resultado: Dos 300 exames de TCFC analisados, os canais mandibulares eram únicos em 210 (70,0%). Nos demais 90 casos constatou-se a presença alterações anatômicas no canal mandibular, indicando que a taxa de prevalência dessa condição na amostra foi de 30,0%. A ocorrência dos canais retromolares foi observada em 15 pacientes da amostra total (5,0%), sendo 06 pacientes do gênero masculino e 09 pacientes do gênero feminino. Conclusão: Ratifica-se a importância de um minucioso conhecimento da região retromolar devido a grande prevalência de cirurgias realizadas na região posterior da mandíbula, a fim de ter previsibilidade nos planejamentos e consequentemente otimizar os procedimentos anestésicos e cirúrgicos realizados, minimizando as falhas anestésicas e os acidentes cirúrgicos.Descritores: Cirurgia; anatomia; mandíbula. AbstractIntroduction: Knowledge on the normal morphology of the human mandible and its possible anatomical variations are of fundamental importance in dental practice, especially in the areas of surgery and implantodontics. The retromolar region is delimited by the anterior margin of the ramus of the mandible, the temporal crest and the distal surface of the last lower molar. In this area, a retromolar canal may be observed emerging through the retromolar foramen. Objective: This study aims to evaluate the prevalence of retromolar canals in cone beam computed tomography (CBCT) images and to correlate it with their possible clinical repercussions. Material and method: 300 CBCT images were selected from the Department of Radiology of the São Leopoldo Mandic Dental School. This was an observational descriptive study and all the images were processed and analyzed on XoranCat  . Result: Of the 300 CFCT scans analyzed, a single mandibular canal was observed in 210 (70.0%). In the remaining 90 cases, anatomical changes were observed relating to this canal, indicating that the prevalence of this condition in this sample was 30%. The prevalence of retromolar canals was observed in 15 patients (5.0%), of which 06 were in males and 09 in females. Conclusion: The importance of a full ...

Objetive The aim of this study is to establish the prevalence and classification of mandibular canal alterations using cone beam computed tomography (CBCT) in different facial types. This research was submitted and approved by the research ethics committee, registration number 2.065.839. Material and method The sample consisted of 90 CBCTs from the São Leopoldo Mandic Dental School database (Campinas-SP), divided into three groups according to brachycephalic, dolichocephalic and mesocephalic facial types. Result Of the 90 patients, 23 presented bifid mandible canals (25.6%), of which 60.9% were in males and 39.1% in females. In 39.1%, the canal bifurcation occurred towards the retromolar region (class D), 21.7% had a trajectory to an alveolar or upper direction (class C) and 13.1% were classified as C-E. For the remaining classifications (A, E, F and A-E), the frequencies were in the range of 8.7% to 4.3%. None of the 23 cases of mandibular canal bifurcation was classified as B (mesial direction). Conclusion According to the results obtained from this study, the prevalence of bifid mandibular canals was found to be 25.6%, with class D being the most prevalent for the retromolar region and the highest occurrence was unilaterally on the left side. When evaluating the occurrence of bifid mandibular canals in relation to facial types, brachycephalic patients were the most affected.