Additive Versus Subtractive Manufacturing Techniques of Custom-Made Plates for the Fixation of Interforaminal Mandibular Fractures

Overview

This study aims to compare the mechanical properties, including tensile strength, shear strength, and flexural strength, as well as the clinical outcomes of additive and subtractive manufacturing techniques used to fabricate custom-made plates for the fixation of interforaminal mandibular fractures. A total of 16 patients were included and allocated into two groups: one treated using plates fabricated with the additive manufacturing technique and the other with the subtractive manufacturing technique. Mechanical performance was evaluated using standardized biomechanical testing, while clinical outcomes were assessed during scheduled postoperative follow-up visits. The objective of the study is to determine which fixation approach provides superior biomechanical performance and favorable clinical healing outcomes.

This randomized clinical study included 18 patients who were assessed for eligibility. Two patients were excluded-one did not meet the inclusion criteria and another declined participation-leaving a final sample of 16 patients who were randomly allocated into two equal groups (n=8 per group). All included patients were followed throughout the entire study period, and none were lost to follow-up. Both study groups demonstrated comparable baseline characteristics with no statistically significant differences regarding age, sex distribution, trauma side, cause of injury, type of fracture, and operative time. All surgical procedures were performed using standardized operative protocols, and postoperative evaluations were conducted at fixed intervals. Clinical outcomes included wound healing status, postoperative edema, infection, and wound dehiscence. Functional performance was evaluated through maximum mouth opening measurements and patient-reported outcomes involving occlusion and self-chewing ability. Radiographic and mechanical assessments were also performed, including tensile strength, shear strength, and flexural bending tests for the fixation systems used in each group. Across the follow-up period, both groups showed satisfactory wound healing, absence of infection or dehiscence, progressive improvement in mouth opening, and gradual restoration of occlusal stability and chewing function, with no significant intergroup differences in clinical parameters. Mechanical testing demonstrated significant differences between the two fixation systems. All collected data were statistically analyzed, and outcomes were reported in accordance with CONSORT guidelines.