Diagnostic accuracy of panoramic radiograph vs cone beam computed tomography in assessing the relationship with the inferior alveolar nerve.

Abstract

Aim: To evaluate whether the use of CBCT, with its additional information, alters the preoperative assessment for lower third molar extraction compared to OPG, and subsequently leads to a different surgical approach. Objectives: To identify radiographic indicators of the proximity of the third molar to the inferior alveolar nerve using OPG, and to evaluate and compare the relationship between the lower third molar and the inferior alveolar nerve as assessed by CBCT and OPG. Materials and methods: This study involved 100 participants. CBCT images were used to assess the relationship between the inferior alveolar canal (IAC) and impacted mandibular third molars (IMTM), the IMTM's position relative to the IAC, mandibular morphology, IMTM type, and the number of roots. OPG images were used to measure IMTM roots and evaluate radiographic findings (root darkening, IMTM diversion, narrowing, and interruption of the white line). A chi-square test was used for data analysis. Results: A significant relationship was observed between the position of the IAC-IMTM, where 27% of the IAC was having a lingual contact with the IMTM as compared to 1% of the cases where it was separately placed. Conclusion: The number of roots could not be accurately determined by panoramic radiography images. There is a benefit to using CBCT for the detection of multiple roots of IMTM. It was more likely that the IMTM and IAC would be in contact when the roots darkened and the white line was interrupted on panoramic images.

Keywords: IMTM(Impacted mandibular third molar), IAC (inferior alveolar  canal), OPG(Orthopantomogram),  CBCT (Cone beam computed tomography), CT (conventional Computed  tomography)