The prevalence of mandibular retromolar canals on cone beam computed tomography and its clinical repercussions

Abstract

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 ...

Prevalence evaluation and classification of bifid mandibular canals in CBCT exams in different facial types

“…When observing the relative frequency of mandibular canal bifurcation according to its classification in the present study, class D (retromolar direction) was the most prevalent with 39.1% of cases of mandibular canal bifurcation. Freitas et al 17 found a prevalence of 19.4% of retromolar bifid canals in their study. The second most prevalent classification was class C (alveolar direction), which occurred in 21.7%.…”

“…The sample was divided into 3 groups according to facial types: CT scans were all obtained from the I-Cat  (Imaging Science, Hatfield, PA) equipment with Fov 20 cm, voxel 0.25 mm and 20s, Kvp120 and 36mA. The sample size was based on previous recently published studies [16][17][18] .…”

Incidence of retromolar canal in Egyptian population using CBCT: a retrospective study

“…Results in the current study were analyzed and tabulated using the Statistical Package for Social Science (SPSS) software as described by Freitas et al for their statistical analysis [27]. Intra-reviewer analysis and inter-reviewer analysis were done to determine the reliability of measurements, frequencies, and percentages to find the percentage of RMF in the sample, and χ 2 (chi-square test) and Fisher's exact test were calculated to identify the significant incidence.…”

“…It is quite obvious that there is a vast difference between the incidence rate reported in panoramic studies due to the limitation of being a 2D modality and CBCT studies; several studies have reclaimed incidence rates of 3-8% [14,23,28] and 7.3-75.4% [5,27] in panoramic and CBCT studies, respectively. 11.2% was reported in this study which falls in the range of the previously reported studies.…”

“…The wide range of incidence rate of RMC in different studies can be attributed also to the sample size difference in each study and the inclusion and exclusion criteria; a study with large sample size 300 CBCT scans which was done on the Brazilian population showed an incidence rate of 5 % only [27], while the study done on 84 CBCT scans only of the Chilean population showed an incidence rate of 23.8% [35].…”