Role of third molars in mandibular fractures: a systematic umbrella review with updated meta-analysis
TL;DR
Third molars are associated with a higher observed risk of mandibular angle fractures, but they were associated with a lower observed risk of condylar fractures, which indicates clinical decision on the prophylactic removal of the third molar should balance the risks of angle vs. condylar fractures.
Abstract
Background and aims Previous meta-analyses (MAs) and systematic reviews (SRs) reported that presence of third molars increases the risk of angle and decreases the risk of condylar fractures, but the data is dispersed across these studies. The aim of this umbrella review is to pool quantifiable data from the previous MAs. Methods This umbrella review searched the PubMed, Embase and Web of Science databases through June 2026 in accordance with PRISMA recommendations. The MAs that looked at the relationships between third molars and mandibular fractures were included. The odds ratios (OR) and risk ratios (RR) for angle and condylar fractures were the main extraction data. The Newcastle-Ottawa Scale (NOS) criteria were applied for quality assessment and the GRADE tool was utilized to evaluate evidence certainty. Results A total of 8 MAs with ∼40 thousand participants were included. Due to the high overlap across these MAs, only 32 unique primary studies were selected from these reviews. Further, an additional 10 studies were included from an independent literature search. In total, 42 studies encompassing ∼16 thousand participants were included for an updated meta-analysis. Third molars were associated with a significantly higher observed risk of mandibular angle fractures (RR 2.18, 95% CI 1.66–2.87, p < 0.0001) but they were associated with a significantly lower observed risk of condylar fractures (OR 0.28, 95% CI 0.19–0.43, p = 0.001). Most of the subgroup and sensitivity analyses showed the consistency of the results. However, both outcomes received “very low” rate of evidence certainty, mostly due to the observational nature of the included studies, significant heterogeneity and publication bias. Conclusions Third molars are associated with a higher observed risk of mandibular angle fractures, but they were associated with a lower observed risk of condylar fractures. Clinical decision on the prophylactic removal of the third molar should balance the risks of angle vs. condylar fractures. Definitive preventive strategies require well-designed prospective research. Systematic Review Registration The protocol of this review is registered in PROSPERO database with the registration number of CRD420251121903.