DOI: 10.36347/sjds.2017.v04i12.003

Pages: 540-546

Preoperative radiographic examination of mandibular third molars (MTM) is essential to prevent inferior alveolar nerve injury during extraction. The purpose of this study was to assess the reliability of panoramic signs of the relation between the roots of mandibular third molars (MTM) and the mandibular canal (MC), and to compare panoramic signs with 3D exploration findings. A prospective study performed in the department of oral medicine and oral surgery at the university dental clinic of Monastir during one year, from April 1st 2014 to March 31st 2015. An information sheet was completed for each patient who underwent an extraction of MTM. A sample of these patients benefited from an anatomo-radiological study of their extracted MTM. The representative sample included 1679 patients with a mean age of 31 ± 13 years and a sex ratio of 0.61. The most common cause of MTM extraction is pericoronitis (67.85%). Panoramic radiography of 224 mandibular third molars was evaluated to determine the relation of the MTM roots to the MC. The most radiographic sign was the interruption of the white line (56%) and darkening of the roots (19.64%). A 3D exploration was requested for 12.5% of the cases 67.85% of which showed contact between the MC and the root tip of the MTM. Interruption of the white line and darkening of the roots on panoramic radiographs might be highly suggestive of the risk of nerve injury.