Evaluation of impacted mandibular third molar position in relation to mandibular canal on panoramic radiography compared to cone-beam computed tomography

The serious complications associated with odontectomies include inferior alveolar nerve injury. The position of impacted mandibular third molars, against the mandibular canal must be accurately determined by radiological examination including two dimensional (panoramic radiograph) and three dimensional (CBCT Scans). We evaluated the positions of impacted mandibular third molars proximal to mandibular canal on a panoramic radiograph based on CBCT scan. This study used descriptive analysis of panoramic radiograph and DICOM file CBCT Scans. Subjects meeting inclusion criteria were recruited from several healthcare facilities in Jakarta August 2017 until December 2017. We used a computer equipped with Macinthos or Windows operating system and Planmeca Romexis ® Imaging Software Viewer. Data were analyzed using SPSS version 22 and Chi-Square tests. Our review of 108 patients produced 177 teeth samples and 48 patients data resultant 61 teeth samples met inclusion criteria. The most common positions we observed on panoramic radiography was increasing radiolucency. On CBCT scans, the inferior position was the most commonly observed position. There was a statisticaly significant relationship between panoramic radiography and category of lingual-buccal-inferior positioning on CBCT scan. Our result could be used to evaluate the position of mandibular third molars against the mandibular canal to help reduce risk of inferior alveolar nerve injury during odontectomy.