Analyzing the Relationship of Inferior Nerve Canal to Impacted Mandibular Third Molars Using Cone-beam Computed Tomography

Aim: To evaluate the place of inferior alveolar canal in relationship to the angulation of the impacted mandibular third molars using cone-beam computed tomography (CBCT). Materials and methods: A total of 150 patients with an impacted third molar and had undergone a preliminary orthopantomogram (OPG) were included in the present study. The position of the inferior alveolar nerve block (IANB) was then evaluated using Maglione’s CBCT classification of position of inferior alveolar nerve (IAN), with emphasis on the quantitative and qualitative position of the nerve to the tooth apex, contact, if any, with the third molar, and disfigurement of the canal circumference if contact was established. Data were recorded and statistically analyzed. Results: Inferior alveolar nerve is most commonly present inferiorly to the tooth apex (66.6%), and usually in close proximity of less than 2 mm (60%), with almost 40% being in direct contact with the nerve. While horizontal impactions show least contact, around 68.6% of distoangular impactions show contact with the nerve. Mesioangular impactions were the most encountered type in this study (45.3%). A total of 81.3% of the impacted teeth in the present study had contact with the lingual cortical plate. Conclusion: On conclusion, the mandibular canal was majorly positioned inferiorly to the mandibular third molar and mostly within 2 mm of proximity to the tooth. And mesioangular impactions are the most common type of impactions according to the results of the study. Clinical significance: Cone-beam computed tomography provides the surgeon with an accurate rendering of the connection between the inferior alveolar canal and the mandibular third molar. This improved comprehension of the anatomical linkages of a modified surgical approach that could be required to replace teeth enables the surgeon to lower the risk associated with surgical planning.