Introduction: The mandible represents the predominant site of fractures within the maxillofacial complex, with its body exhibiting the highest incidence. The clinical application of the champy technique, which utilizes monocortical screws and miniplates for osteosynthesis, is complicated by the presence of accessory mental foramina (AMF), posing significant risks during interforaminal fracture management. This study aimed to quantify the risk of iatrogenic injury during interforaminal fracture fixation using the Champy technique in a South African cohort by analyzing AMF prevalence, spatial relationships, and minimum buccal bone (MBB) thickness.
Methods: A morphometric analysis of 213 dry hemimandibles was conducted. AMF continuity with the mandibular canal was verified via latex injection. MBB thickness was measured at three horizontal planes (superior, foraminal, and inferior) relative to the mental foramen. Data were analyzed using IBM SPSS software, version 25. Normality was assessed via Shapiro-Wilk tests. MBB thickness comparisons across planes employed one-way analysis of variance (ANOVA) with Tukey post-hoc pairwise testing. Independent t-tests evaluated bilateral differences, while injury risks for screw lengths (4–7 mm) were calculated as a percentage of screw overlaps with vital structures relative to the total number of screw sites. G*Power software, version 3.1. was used for power analysis followed with a post hoc power analysis; mean values and standard deviations (in mm) were calculated with a 95% confidence interval (CI), while P<0.05 was considered statistically significant.
Results: AMF prevalence was 6.54% (right) and 6.60% (left), with one AMF (0.93%) near a screw site. The foraminal plane had the thickest MBB (left: 6.91±2.08 mm; right: 6.69±2.04 mm) and lowest injury risk (3.44–7.55%). The inferior plane showed higher risks (up to 33.02%). 
Conclusion:  The foraminal plane is the safest for miniplate placement. By tailoring the champy technique to the unique anatomical characteristics of the South African population, surgeons can enhance the safety and efficacy of interforaminal fracture fixation, ultimately reducing the risk of iatrogenic injuries.