One-plate versus two-plate fixation in the treatment of mandibular angle fractures: a retrospective two-centre comparative study.

Background: The treatment of mandibular angle fractures remains controversial, particularly regarding the method of fixation. The primary aim of this study was to compare surgical outcomes following treatment with 1-plate versus 2-plate fixation across two oral and maxillofacial surgery clinics. The secondary aim was to evaluate associations between patient-, trauma-, and procedure-specific factors with postoperative complications and to identify high-risk patients for secondary osteosynthesis.

Methods: In this retrospective two-center cohort study, patients who underwent surgical treatment for mandibular angle fractures via a transoral approach using either 1-plate or 2-plate fixation over a 10-year period were included. Clinic A exclusively performed 1-plate fixation, while clinic B used 2-plate fixation. Demographic, clinical, radiological, and treatment data were analysed. Multivariable analyses were conducted to identify predictors of postoperative complications and secondary osteosynthesis.

Results: A total of 253 patients with 264 mandibular angle fractures were included. Violence was the most common mechanism of injury (n = 131; 49.6%). Postoperative complications occurred in 34.6% of the cases at clinic A and 26.8% at clinic B (p < 0.0001). Secondary osteosynthesis was required in 9.4% at clinic A and 7.6% of the cases at clinic B, respectively (p = 0.6547). Multinomial regression analysis identified smoking, diabetes mellitus, patient noncompliance, left-sided mandibular angle fractures, presence of a third molar (M3), partial M3 eruption, vertical depth A of M3 and horizontal impaction class II (Pell and Gregory) as significant predictors of postoperative complications. Logistic regression analysis identified smoking, diabetes mellitus, patient noncompliance, left mandibular angle fractures, mandibular angle und body fractures and presence of third molars as significant predictors of secondary osteosynthesis. As patient age there is an increased tendency for wound infection and plate/screw loosening (p = 0.06). A longer interval between trauma and surgery was associated with a higher risk of postoperative occlusal disturbances (p = 0.06). Patients with a longer duration of postoperative IMF were significantly associated with a higher rate of wound infection and secondary osteosynthesis (p < 0.05).

Conclusions: Both 1-plate and 2-plate fixation techniques demonstrated acceptable outcomes. Single-plate fixation offers sufficient stability for most mandibular angle fractures with fewer complications, supporting its use in uncomplicated cases. Double-plate fixation may be reserved for complex cases. Higher complication rates were associated with patient-related and anatomical risk factors. Individualized treatment and further prospective studies are needed to refine surgical strategies.