Statement of the problemThe clinical decision to pursue open reduction and internal fixation (ORIF) vs. closed treatment (CT) to treat mandibular condyle fractures has been long contested but predicated on understanding of absolute and relative indications and contraindications. This meta-analysis critically appraised the literature to compare and contrast clinical outcomes following these interventions. Materials and methodsA systematic review and meta-analysis were performed to test the null hypothesis of no difference in clinical outcomes in ORIF vs. CT of mandibular condyle fractures. ORIF also was compared to endoscopically assisted open treatment. The PubMed, EMBASE, Cochrane Library, Elsevier text mining tool database and ClinicalTrials.gov trial registries were accessed from 1946 to 2020. The quality of evidence was determined using Grading of Recommendations Assessment, Development and Evaluation methodology. No pediatric studies were included. The quality of evidence was downgraded due to risk of bias and imprecision in specific outcomes in observational studies. Data analysisTwo authors extracted the following data from included studies: country of origin, study design, study period, number of patients, patient characteristics (i.e., age range, gender, ethnicity), fracture laterality (unilateral vs. bilateral), treatment used (CT vs. ORIF), and clinical outcomes. The study analyzed the data separately according to fracture location and study design (e.g., RCTs and observational studies). An experienced medical librarian was consulted on methodology and ran a medical subject heading (MeSH) analysis of known key articles provided by the research team to ensure complete capture of all articles pertaining to management of condylar fractures. In each database, the study ran scoping searches and used an iterative process to translate and refine the searches. Results and outcomes dataOf 1507 screened articles, 14 met the inclusion criteria. There were 4 meta-analyses that were included, examining 7 randomized controlled (RCTs) trials and 31 non-randomized studies. Primary studies enrolled adults with displaced uni- or bilateral condylar fractures and did not report the results by fracture location (e.g., subcondylar or condylar) except with 2 RCTs that included all adults with subcondylar fractures. Primary studies compared the outcomes after open surgical procedure with those of fixation using 1 or 2 miniplates with various diameters. Open reduction and internal fixation were favored significantly when evaluating temporomandibular joint pain (RR 0.3; 95% CI 0.1-0.7) (NNTp 3; 2-6), laterotrusive movements of the mandible (MD 2.3; 1.7-3.0) (SMD 0.9; 0.4-1.3), and malocclusion (RR 0.5; 0.4-0.7) (NNTp 19; 10-200). However, open treatment yielded higher incidence of postoperative infection (RR 3.6; 95% CI 0.9-13.8). With respect to ORIF versus endoscopically assisted open treatment, no difference was seen in overall patient satisfaction with postoperative mandibular movement, disturbance to articulation, or occlusion. ConclusionMeta-analysis of high-level evidence in randomized controlled trial data suggests ORIF yields significantly superior clinical outcomes when evaluating restoration of translational and rotational mandibular movement, alleviation of pain, and restoration of occlusion and symmetry, although it is associated with higher risk of postoperative infection and facial nerve injury. These long-term benefits must be weighed against the increased risk of postoperative infection in ORIF; thus, treatment should be patient-specific. Future investigations with high-level evidence may further elucidate the relative effectiveness and safety of various open, endoscopic, and closed techniques in patients with facial trauma.