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.