RELATIONSHIP OF MANDIBULAR THIRD MOLARS TO THE SURROUNDING STRUCTURES

Abstract

Background Surgical extraction of the mandibular third molar is the most common procedure in oral surgery. Panoramic radiography and cone beam computed tomography (CBCT) are the imaging modalities used for preoperative planning. Objective The aim of the study was to evaluate the position of the mandibular third molar and its relationship to the surrounding structures, mainly the mandibular canal. Materials and methods CBCT images of 712 adult patients with third molars were selected in a specific period. Most of the scans were conducted for routine examination or for preimplantation screening, and some of them were performed for the assessment of the relationship between the third molar and the mandibular canal. The molars were classified on the basis of the following parameters: (1) patient gender, (2) presence of an adjacent second molar, (3) impaction angle, (4) depth of impaction, (5) parietal–lingual localization, (6) number of roots, (7) roots of molars in relationship to the mandibular canal, and (8) shape changes of the mandibular canal in relationship to the third molar. Results The vertical angulation is the most frequent location of impacted and semi-impacted third molars. The mandibular canal is identified most frequently under the buccal roots of the molars, and this is has been confirmed by various studies reported in the literature. There is also a large number of cases with mandibular canal narrowing and cortical plate loss, close to the third molar. Discussion CBCT is essential for the topographic evaluation of wisdom teeth because of the anatomic particularity they may present. The information CBCT offers on the relationship between various types of impaction and the mandibular canal may be helpful in the formulation of the preoperative plan and in avoiding potential risks during extraction.