Assessment of Risk Factors Associated with Inferior Alveolar Canal Integrity During Extraction of Mandibular Third Molar: A Field Study Using Cone Beam Computed Tomography Scan

Abstract

This study aimed to assess the diagnostic effectiveness of cone beam computed tomography in delineating the spatial relationships between mandibular third molar roots and the mandibular canal, and to determine how anatomical variations and demographic factors correlate with mandibular canal wall integrity in a Yemeni population. A retrospective cross-sectional study was conducted on 344 cone beam computed tomography scans from Yemeni patients. Scans were analyzed to classify mandibular third molar impaction types (Winter and Pell & Gregory classifications), root position relative to the mandibular canal (Ghaeminia classification), and mandibular canal wall integrity (intact or defective). Demographic data (age, gender) and panoramic radiographic signs were also evaluated. The analysis revealed that root positioning significantly influenced mandibular canal integrity. Roots located buccal to the mandibular canal had the highest prevalence of wall defects (85.94%), followed by lingual (36.67%) and superior positions (26.56%). Vertical impactions and high-depth impactions (Pell & Gregory Class A) were associated with a lower risk of MC defects. While no significant gender-based differences were found, older patients (>60 years) exhibited a higher rate of defective canals (70%) compared to younger groups. Cone beam computed tomography demonstrated superior diagnostic accuracy over panoramic radiography, particularly in identifying critical risk features like cortical wall interruption and canal diversion. This study identifies buccal root positioning relative to the mandibular canal as the paramount risk factor for cortical wall defects, observed in 85.94% of such cases. Horizontal and mesioangular impactions, along with advanced patient age (>60 years), were also significant predictors of compromised MC integrity. Cone beam computed tomography proved superior to panoramic radiography in diagnosing these high-risk anatomical relationships, particularly for detecting bucco-lingual positioning and subtle cortical defects. Consequently, preoperative cone beam computed tomography is strongly indicated for cases with panoramic signs of proximity (e.g., interrupted white line, diversion) to enable risk-stratified surgical planning, such as considering coronectomy or precise tooth sectioning, to mitigate inferior alveolar nerve injury during third molar extraction in the Yemeni population.