Mandibular incisive canal-related prevalence, morphometric parameters, and implant placement implications: a multicenter study of 847 CBCT scans

BACKGROUND: This study evaluated the epidemiological and morphological features of the mandibular incisive canal (MIC) using cone beam computed tomography (CBCT) in a significant sample of subjects in Brazil. MATERIAL AND METHODS: This retrospective, multicenter study assessed 847 CBCT scans performed at four oral imaging centers. The sample comprised CBCT images acquired from dentate individuals who presented at least from tooth 35 to tooth 45 in the anterior mandible region. Data regarding patient sex and age, and MIC linear measurements (length and diameter in mm), anatomical distances (to the alveolar, buccal and lingual cortexes, inferior border of the mandible, and adjacent teeth apexes), and location were obtained. RESULTS: The MIC was more prevalent in women (76.3% [p<0.001]) between the fourth and sixth decades of life (p<0.001). It was present bilaterally (p<0.001) and exhibited a mean length of 7.7 mm (standard deviation [SD]=3.7 mm). Spearman correlation and logistic regression analysis revealed collinearity between age and linear measurements (p<0.05). The mean distances varied from the initial to the final portion of the MIC, respectively, in relation to the buccal cortex (mean=2.6 mm, SD=1.27; mean=3.96 mm; SD=1.43), to lingual cortex (mean=5.13 mm; SD=1.7; mean=4.61 mm, SD = 1.65), and to the inferior mandibular border (mean = 9.32 mm, SD=1.92; mean=8.76 mm, SD=2.07 mm). The difference in the proximity of the MIC to the apex of the inferior lateral incisor was statistically significant (p<0.05). CONCLUSIONS: Results of this study revealed a high prevalence of MIC with a bilateral pattern in women who were between the fourth and sixth decades of life. Both the distance between the MIC and the lingual cortex of the mandibular alveolar bone, and the diameter of the MIC, decreased as its trajectory assumed a more anterior position. Key words:Mandibular incisive canal, cone-beam computed tomography, mandible, cross-sectional studies, anatomy.