Infective complications from the use of calcium phosphate paste in mandibular lengthening surgeries: a prospective study after implementation of learned precautions.

In sagittal split osteotomy (SSO), unaesthetic notching of the lower mandibular border can occur postoperatively, particularly after significant advancements. This single-centre, prospective study evaluated whether applying calcium phosphate paste to prevent these defects increases the risk of surgical site infection. A total of 234 patients who underwent mandibular lengthening at the European Face Centre in Brussels between 2017 and 2022 were included. The predictor variable was the use of calcium phosphate paste at the lower mandibular border, while the primary outcome was the incidence of infective complications at the SSO site. Secondary outcomes included hardware removal and intraoperative complications. Minimum follow-up was 6 months. Fourteen patients (6.0%) developed an SSO-site infection. T-test and logistic regression analysis showed a significant difference in infection at the SSO site between the calcium phosphate group (n = 8, 11.3%) and control group (n = 6, 3.7%) (odds ratio 3.3, 95% confidence interval 1.1-9.9, P = 0.032). Although the higher infection risk remained significant after adjusting for age and sex, it lost significance when adjusted for amount of mandibular advancement. The study findings support the use of calcium phosphate paste due to its long-term benefits in mitigating jawline notching, outweighing the manageable infection risk.