Should Degree of Third Molar Eruption Influence Operative Management of Mandibular Angle Fractures? A Systematic Review

Objective: There is a growing trend toward evidence-based management of third molars in the fracture line of mandibular angle fractures (MAFs). This study aimed to differentiate MAF fixation complications by degree of third molar eruption and by extraction strategy in patients undergoing Champy fixation. Methods: PubMed, EMBASE, OVID, SCOPUS, the Cochrane Library, and clinicaltrials.gov were queried through May 2020 for English-language publications for MAFs with third molar involvement for this systematic review. Bias was assessed using author-defined criteria. Relative risk (RR) of post-operative complications associated with extracted unerupted and retained partially erupted third molars (Group I) was calculated against controls of retained unerupted and extracted partially erupted third molars (Group II). Results: Ten studies reported complications by eruption or extraction; however, only one study stratified complications by both eruption and extraction to meet inclusion criteria. The risk of bias was medium as only cases meeting defined follow-up were included. 73 cases (N) were included: 34 qualified for Group I and 39 for Group II. Quantitative synthesis of individual case data demonstrated significantly higher complication rate in Group I compared to Group II (23.5% vs 5.1%) (RR 4.6, 95% CI 1.04-20.1). No significant differences were observed between groups for infectious complications, mechanical complications, nonunion, or dehiscence. Reoperation was required significantly more often for Group I (P = .043). Conclusions: For MAFs involving the third molar, concomitant extraction of unerupted as well as retention of partially erupted third molars increases risk of complications with Champy fixation technique. For these patients, alternative strategies for fixation should be considered.