Purpose: The aim of this study is to assess the reliability of seven panoramic radiographic markers in predicting the absence of corticalization between the mandibular canal and the third molar which carries the risk of inferior alveolar nerve injury during extraction on cone beam computed tomography images. Materials and methods:The study samples consisted of 270 impacted third molars from 136 patients who showed a close relationship between the mandibular canal and third molars on panoramic radiographs and were referred for the examination with CBCT to assess the relationship between the tooth and the mandibular canal. Panoramic images were evaluated for the seven radiographic markers. CBCT images were used to assess the continuity of the mandibular canal cortical bone. The association of the panoramic and CBCT findings was examined using a Chi-square test and Fisher's exact test.Results: Panoramic radiographic markers were statistically associated with CBCT findings (P<0.01). In cases of darkening roots, interruption of white line as an isolated finding or in association with each other.Conclusion: Panoramic radiography is an effective and efficient method for the assessment of impacted mandibular third molars. Interruption of white line and darkened roots on panoramic radiographs, as both isolated findings and in association with each other are effective in determining the relationship between the tooth roots and the mandibular canal requiring evaluation with cone beam computed tomography.

No abstract