KHẢO SÁT ĐẶC ĐIỂM GIẢI PHẪU THẦN KINH XƯƠNG Ổ DƯỚI TRÊN HÌNH ẢNH CBCT Ở XƯƠNG HÀM DƯỚI NGƯỜI VIỆT

Abstract

Objectives: The mandibular canal contains the inferior alveolar neurovascular bundle and is a critical structure in dental and maxillofacial procedures. This study aimed to evaluate the course, diameter, and three-dimensional spatial relationships of the mandibular canal at the mandibular first and second molar regions using cone beam computed tomography (CBCT). Materials and Methods: A descriptive cross-sectional study was conducted on 345 CBCT images of the mandible from patients aged ≥18 years at the Faculty of Dentistry, University of Medicine and Pharmacy at Ho Chi Minh City. The course of the mandibular canal was classified on the sagittal plane (Types A, B, C) and axial plane (Types A1, A2). The presence of bifid canals was recorded. Canal diameter was measured in superoinferior and buccolingual dimensions. Distances from the canal to the tooth apex, buccal and lingual cortical plates, and inferior border of the mandible were measured at the mesial and distal roots of the first (R6) and second (R7) mandibular molars. Statistical analysis was performed with p < 0.05. Results: On the sagittal plane, Type C was the most common configuration (67.10%), followed by Type B (24.20%) and Type A (8.70%), with significant differences by sex and side (p < 0.05). On the axial plane, Type A1 predominated (86.37%). The prevalence of bifid mandibular canals was 5.36%. The mean canal diameter at the mandibular foramen was 4.48 ± 0.75 mm, with no significant differences by sex or side. In the molar region, the mandibular canal was consistently closer to the lingual cortical plate than to the buccal plate and located closer to the inferior mandibular border at R7 than at R6, with the distal root of R7 representing the highest risk area. Conclusions: Despite a relatively stable canal diameter, the mandibular canal shows considerable positional variation, particularly in the second molar region. CBCT is essential for accurate preoperative assessment and for minimizing inferior alveolar nerve injury.