Measurement of the Lingual Position of the Lower Third Molar Roots Using Cone-Beam Computed Tomography

Purpose: The aim of this study was to evaluate the distance between the roots of the impacted third molars and the floor of the mouth to predict the risk of lingual root displacement during surgery. Materials and Methods: Thirty-one patients (5 men and 26 women) were evaluated for this study using cone-beam computed tomography (CBCT). The teeth were grouped according to their position on the orthopantomogram as vertical, mesioangular, horizontal, and distoangular. The distance between 2 points on the roots and lingual soft tissues was measured. Results: The average distance between the apex of the root, which is in the most lingual position, and the lingual cortical plate was 1.03 mm. The average distance between the most lingual point on the apical half of the root, which is in closer proximity, and the lingual cortical plate was 0.65 mm. Conclusion: The distance between the apices and the lingual plate is very short, which allows displacement of broken roots or teeth, especially when the lingual plate is perforated. (C) 2015 American Association of Oral and Maxillofacial Surgeons