Comparison of skeletal stability between single plate osteosynthesis and double plate osteosynthesis in anterior mandibular osteotomies: a randomized case-control trial.

[BACKGROUND] The aim of the current study is to compare the skeletal stability of single-plate versus double-plate osteosynthesis in anterior mandibular osteotomies.

[METHODS] A prospective case-control trial was planned, enrolling all the patients who reported to us for the correction of anterior mandibular issues, including patients planned for lower anterior sub-apical osteotomies and genioplasties. The patients were randomly allocated to two groups Group I (single plate fixation) and Group II (two plate fixation) based on the Lot method. The patients in each group were further divided into subgroups, with Subgroup A undergoing subapical setback and Subgroup B undergoing advancement genioplasty. All the patients underwent preoperative clinical and cephalometric evaluation (T1) to assess the magnitude of movement of the anterior mandibular segments. All the patients had an immediate post-operative cephalogram done (T2). They were under follow-up for 6 months to 3 years (T3), and the post-operative skeletal stability was assessed using COGS analysis on a lateral cephalogram between T3 and T2. Intraoperative time and postoperative neurosensory disturbances were the secondary outcomes that were measured. G power analysis was used to calculate the sample size, and statistical analysis used SPSS (version 23.0), employing ANCOVA for non-parametric tests (Quade's approach) with significance set at P<0.05.

[RESULTS] Twenty-six patients within the age group of 15 to 35 years (14 females, 12 males) were enrolled in the study. Thirteen patients were allocated to each group. Seven patients underwent genioplasty in group I and seven in group II, and six underwent subapical osteotomy in groups I and six in group II, respectively. The mean magnitude of subapical setback was 7 mm, while the magnitude of chin advancement was 8 mm, and this was comparable among the groups. The cephalometric evaluation involved the evaluation of vertical and horizontal distances of points B, Pog, and menton from the true horizontal and true vertical of COGS analysis. These parameters showed no statistically significant differences in the follow-up period (T3-T2) between single-plate and double-plate osteotomy groups for subapical osteotomies and genioplasties between age and sex-matched control groups. However, secondary outcomes, including neurosensory disturbances, intraoperative time, differed significantly (P<0.05) between groups and favored the use of single plate fixation.

[CONCLUSIONS] This clinical trial suggests that the choice between single-plate and double-plate osteosynthesis does not significantly affect skeletal stability following anterior mandibular osteotomies. However, significant differences were observed in secondary outcomes, indicating potential considerations for surgical approach in orthognathic procedures.