Reliability of CBCT and other radiographic methods in preoperative evaluation of lower third molars.

Objectives: The aim of this study was to compare the reliability of cone-beam computerized tomography (CBCT) with that of other radiographic methods in preoperative radiographic determination of the number of roots of lower third molars and their relationship to the inferior alveolar canal (IAC).

Study Design: Forty-two teeth were clinically studied and imaged using CBCT and other imaging methods-panoramic radiography, multiprojection narrow-beam radiography (MNBR), and cross-sectional tomography. Statistical analysis (kappa values) was used to compare the diagnoses of 2 trained oral radiologists and the radiologic diagnoses with the findings at operation.

Results: Cone-beam CT revealed the number of roots of teeth more reliably than panoramic radiographs. CBCT examination was highly reliable in locating the IAC, whereas MNBR was unreliable and cross-sectional tomography fell between the two. With cross-sectional tomography, the IAC was noninterpretable in one-third of the cases.

Conclusions: We recommend CBCT examination for preoperative radiographic evaluation of complicated impacted lower third molars.