A new system for custom helical mandibular distraction: a bench study on anatomical models

Current mandibular distraction osteogenesis relies on stock or hybrid devices, which can only execute rectilinear or in-plane circular movements. This bench feasibility study evaluated the accuracy of a novel patient-specific helical distractor compared with commonly used rectilinear and hybrid rectilinear devices. Retrospective data from four patients with severe mandibular deformities were utilized. Computer-assisted surgical simulation software was employed to plan ideal distraction paths for each rectilinear and helical case. Three distractors-custom helical, hybrid, and stock-were fabricated for each patient, and three corresponding three-dimensionally printed mandible models were generated to simulate the distraction process to a predetermined distance. The post-distraction models were scanned and compared to the planned treatments by registering landmarks. Helical distractors demonstrated the best performance, with median mandibular landmark misalignment of 1.8 mm, compared to 3.3 mm (hybrid) and 3.6 mm (stock). Occlusal misalignment also favoured the helical devices (0.6 mm) over hybrid (1.0 mm) and stock (0.95 mm). No significant differences were found between hybrid and stock distractors. These preliminary findings suggest that the novel custom helical distractor provides superior accuracy in achieving desired mandibular positioning, offering a promising advancement in mandibular distraction osteogenesis. Further research on larger cohorts is warranted to validate these results.