Assessment of accuracy and efficiency of guided fixation of customized 3D miniplates vs Champy’s technique in stabilization of mandibular angle fractures: A randomized controlled trial

Objectives The objectives of this study were; (1) to assess the accuracy of virtual surgical planning (VSP) and computer aided design and manufacturing (CAD/CAM) in creating an anatomically oriented, bone-borne fracture reduction/plate positioning patient specific surgical guide (PSSG) and a customized three-dimensional (3D) miniplate to achieve anatomical reduction and stabilization of fractured segments in mandibular angle fractures (MAF) via a more esthetic, less complication-laden intraoral access, and (2) to evaluate efficiency of customized 3D miniplates in reestablishment of masticatory function. Methods Twenty-four patients were included and randomly allocated into 2 groups; group I , where open reduction and internal fixation (ORIF) of MAF was performed using a fracture reduction/plate positioning PSSG and a customized 3D miniplate and group II, where ORIF of MAF was performed using a single 2.0 superior border miniplate (Champy’s technique). Assessment of accuracy of VSP in group I was carried out by superimposition of 3D virtual models of virtually preoperatively reduced mandible over those of surgically reduced and stabilized mandibles at 1 week and 6 months postoperatively. Clinical assessments of maximum bite force in Newtons (N) using a bite force measurement device as well as occlusion status according to the following scale: satisfactory (no gap), mild derangement (gap of 1–2 mm) or marked derangement (gap more than 2 mm) were carried out at 1 week, 1, 3 and 6 months postoperatively. Results In group I , superimposition of 3D virtual models of surgically reduced and stabilized mandibles at 1 week and 6 months over the virtually preoperatively reduced mandible revealed a mean surface deviation of 0.36 ± 0.09 mm and 0.45 ± 0.08 mm, respectively. Bite force measurements in group I were significantly higher (p < 0.001) than those in group II at 1 week (20.48 ± 3.20N—13.24 ± 2.83N), 1 month (69.52 ± 3.42N—41.16 ± 3.02N) and 3 months (147.45 ± 3.00N—139.50 ± 3.44N), respectively, with large effect sizes (PES > 0.29). At six months, there was also a statistically significant difference (p = 0.003) between both groups (166.66 ± 2.8N—162.31 ± 3.19N respectively) with higher bite force in group I, however, the effect size was moderate (PES = 0.13). Difference in postoperative occlusion status was statistically insignificant between both groups across all time points. Conclusion Assessment of accuracy of VSP revealed a minimal amount of discrepancy between 3D virtual models of surgically reduced and stabilized mandibles over those of virtually preoperatively reduced mandibles. An anatomically oriented, bone-borne fracture reduction/plate positioning PSSG aided significantly in customized 3D miniplate positioning and fracture reduction. Fractures stabilized with a customized 3D miniplate were associated with higher bite forces when compared to single miniplate fixation, however, this must be interpreted with caution. We recommend that future studies be conducted on a larger sample size. Clinical relevance. Based on the results of this study, we believe that utilizing VSP and CAD/CAM for guided ORIF of MAF using customized 3D miniplates seems to be a promising method, allowing for predictable 3D miniplate positioning and fixation through an intraoral approach and may allow for early reestablishment of masticatory function. Clinical trials registration. This study was registered on ClinicalTrials.gov (ID: NCT06392204), verification date April 2024. https://clinicaltrials.gov/study/NCT06392204