Occlusal Instability Results in Increased Complication Rates After Treatment of Mandibular Fractures

Purpose: It is important to understand the factors that can increase the incidence of complications after mandibular fracture (MF) treatment. The objective of the present study was to investigate whether occlusal stability influences the occurrence of postoperative complications in MFs treated with internal rigid fixation.

Patients and methods: We performed a prospective cohort study of patients treated for MF by osteosynthesis with plate and screw fixation. The primary predictor variable was the occlusal stability (yes vs no). Occlusion was scored as stable (group 1) if the patients had all their teeth and no free ends in either dental arch. Occlusion was coded as unstable (group 2) if the patients were partially edentulous with free ends in either dental arch or had edentulism involving more than 6 dental elements. The primary outcome variable was postoperative complication (yes vs no). The secondary outcome variables were the osteosynthesis system used (2.0 or 2.4 mm), local factors, age, and gender. Statistical analysis was performed using the χ² statistical test at 5% significance.

Results: Of 115 patients with 121 MFs, 73 (63.48%) had stable occlusion (group 1) and 42 (36.52%) had unstable occlusion (group 2). The mean age was 34.11 years, and 71.3% were men. The postoperative complication rate was 8.70% (10 patients). Of the 10 patients with complications, 3 (2.6%) were in group 1 and 7 (6.1%) were in group 2 (P = .021 and P < .05, respectively). The 2.0-mm system was used in 107 cases (93%). All the complications were associated with use of the 2.0-mm osteosynthesis plates, occurring in 3 of 69 patients in group 1 (4.34%) and 7 of 38 patients in group 2 (18.42%; P = .032 and P < .05, respectively). The greatest number of complications was associated with unilateral MF (9 of 109). The occurrence of postoperative complications in angle and symphysis/parasymphysis fracture sites was equal.

Conclusions: The results of the present study suggest that unstable occlusion could increase the rate of postoperative complications in MFs treated with plates and screws. Future studies are required with occlusal stability included as a variable.