Comparison of panoramic radiograph and cone beam computed tomography findings for impacted mandibular third molar root and inferior alveolar nerve canal relation.

Objectives: This study was aimed at determining the specific signs of close relationship between impacted mandibular third molar (IMTM) root and inferior alveolar nerve (IAN) canal as visualised on digital panoramic radiograph or orthopantomograph (OPG) which should indicate as well as contraindicate the need for cone beam computed tomography (CBCT) imaging based on hierarchical model of Fryback and Thornbury.

Materials And Methods: The sample consisted of 120 individuals (200 IMTM) who had undergone OPG as well as CBCT imaging as preoperative radiographic evaluation before surgical extraction. On panoramic radiographs; Rood and Sheehab's radiographic signs of IMTM root and IAN canal, impacted third molar position based on Winter's classification and depth of impaction based on Pell and Gregory's classification were evaluated.