Mandibular Third Molars and Their Influence on Mandibular Angle Fracture Fixation

Abstract

Introduction: Mandibular fractures occur commonly in Singapore and 32% involve the angle. The third molar (M3) predisposes the angle to fracture and is often involved in the fracture site. During fixation, it is often routinely retained but few studies question if this impacts surgical repair and postoperative healing and recommend if it should continue to be done. Aim: To describe all operatively treated mandibular angle fractures (MAFs) with M3 retention over 10 years in a single centre and report any effect of routine M3 retention on fracture fixation or post-operative complications. Materials And Methods: The present study is a retrospective one including all operatively treated MAFs with M3 retention in the National University Hospital, Singapore between January 2001 and December 2010. Subjects below 16 years of age and those with incomplete follow up or Computed Tomography (CT) data were excluded. Hospital records were reviewed for demographic variables and (Seeman’s 7) postoperative complications. OsiriX version 7.5 (Pixmeo., Switzerland) used to characterise the fracture and M3. Analysis was performed using Statistical Package for Social Sciences version 23 (IBM, USA). Results: 23 cases (25 MAFs) were included and the average subject was a 28.8 (SD 4.59) year old male (88%) with a left (64%) simple (84%) MAF with fracture line involving the M3 socket (76%). Concomitant mandibular fractures featured in 14 cases (56%). Most M3 were Class II (76%), Class B (68%) and distoangular (52%). Mean intraosseous M3 length and diameter was 8.33mm (SD 2.09) and 11.70mm (SD 1.89) respectively. The mean mandibular thickness and width was 29.25mm (SD 5.41) and 16.92mm (SD 2.03) respectively. Despite M3s of varying morphology, successful repair was carried out in all cases. Conclusion: Unless the M3 impedes fixation, it need not be removed during fracture fixation.

Keywords

• molar
• mandible
• surgery