Association between lingual canal detection and buccolingual root width in mandibular anterior teeth: a retrospective CBCT Study.

backgroundThe aim of this study was to evaluate the association of buccolingual width (BLW), age, and gender with the detection of a lingual canal in mandibular anterior teeth using cone-beam computed tomography (CBCT).

methodsCBCT images of a total of 360 patients (140 male, 220 female) who applied to the Faculty of Dentistry of Health Sciences University between 2019 and 2022 and met the inclusion criteria were evaluated. Root canal morphology was assessed in sagittal, axial, and coronal sections and classified according to the Vertucci classification system, with specific recording of lingual canal detection. In the sagittal sections of the teeth, two reference points were identified: the cementoenamel junction (CEJ) and the midpoint of the root. BLW measurements were recorded at these levels, and the measurement taken at the midpoint of the root was termed mid-root buccolingual width (mid-root BLW). Separate receiver operator characteristic (ROC) analyses and binary logistic regression were performed to evaluate the association between BLW, age, gender, and lingual canal detection.

resultsA total of 2078 mandibular anterior teeth were examined. All mandibular central incisors were single-rooted, and the vast majority of mandibular lateral incisors (99.9%) and canines (96.8%) were also found to be single-rooted. Lingual canals were detected in 34.5% of central incisors, 29.7% of lateral incisors, and 6.3% of canines. In central and lateral incisors, lingual canals were more frequently observed in males than in females (p < 0.05); however, gender did not remain independently associated with lingual canal detection after regression analysis. In lateral incisors and canines, lingual canals were detected in patients with higher mean ages (p < 0.05), although the magnitude of this association was limited. In contrast, age was not associated with lingual canal detection in central incisors (p > 0.05). BLW at the CEJ and mid-root BLW were significantly greater in mandibular central and lateral incisors with lingual canals (p < 0.05), while in canines, a significant difference was observed only at the mid-root BLW. ROC analysis demonstrated weak discriminatory ability for BLW measurements at the CEJ and moderate discriminatory ability for mid-root BLW measurements in incisors. Binary logistic regression analysis demonstrated that mid-root BLW was the most consistent independent variable associated with lingual canal detection, whereas age showed statistically significant but limited effects.

conclusionsGreater BLW, especially at the mid-root level, was associated with lingual canal detection in mandibular anterior teeth. Nevertheless, BLW showed limited discriminatory value and should be regarded only as supportive anatomical information.