Evaluation of efficacy of lag screw fixation in the management of mandibular parasymphysis fracture

Abstract

Objectives: Mandibular fractures are treated surgically by either rigid or semi-rigid fixation. The focus of this study was to determine the efficacy of lag screws in treating mandibular parasymphysis fractures. Materials and Methods: We conducted a quasi-experimental study in which ten patients with mandibular sagittal parasymphysis fractures were enrolled. In these patients, two 2.0 mm stainless steel lag screws were installed for open reduction and internal fixation. Throughout the study, patients were examined for occlusion, fracture stability, screw location in relation to vital anatomical structures, reduction precision, maximum mouth opening (MMO), biting efficiency, and several other complications on the 1st day, 1st, 2nd, and 6th weeks postoperatively. Results: All parasymphysis fractures had a good bony union after surgery. One patient had mild occlusal discrepancies postoperatively, and statistical significance was found between preoperative and postoperative occlusion (P < 0.0004). Only one patient had abnormal mobility between the fracture lines postoperatively, with a highly meaningful statistical observation (P < 0.001). The comparative statistical analysis of MMO at different follow-up periods showed highly significant (P < 0.00001) results. Substantial improvement in biting effectiveness yielded a high statistical significance (P < 0.00001). There was no evidence of postoperative complications such as wound infection, wound dehiscence, intraoral screw exposure, or mental nerve injury in any of these patients. Conclusions: Lag screw fixation is a realistic and reliable method of internally fixing mandibular parasymphysis fractures. This technique allows the skilled surgeon to achieve optimum stability and functional healing by using the least amount of material.