3D Assessment of Adult Mandible Symmetry
Lucas A. Dvoracek, Samantha Maliha, Tarek Elgendy, Michael Bykowski, Mario Solari
University of Pittsburgh
Presenter: Lucas Dvoracek
All work is the presenter's own as described.
Director Name: Vu T. Nguyen
Author Category: Resident Plastic Surgery
Presentation Category: Clinical
Abstract Category: Craniomaxillofacial
Introduction: Shaping recon bars for highly comminuted hemimandible fractures to achieve bony reduction and reestablish occlusion is a tedious aspect of mandibular fracture fixation but is necessary to organize and reestablish continuity of the mandible. Creation of a template 3D-printed model of the mirrored unaffected hemimandible could allow fixation plates to be molded prior to operative intervention, increasing accuracy and efficiency. As a precursor to this application, this study sought to evaluate the bilateral mandibular symmetry to validate the use of this technique.
Methods: Patients who sustained non-mandibular facial fractures treated by a single surgeon and had a high-resolution fine-cut CT scan were identified from a period of 5 years. Mandibles were digitally reconstructed, segmented, mirrored, and overlapped. The area along the inferior edge of the mandible (where a recon plate would rest) was evaluated for symmetry through a vertex-vertex distance calculation and descriptive statistics by mandibular region.
Results: 49 patients were identified (M:F 39:10), mean age 41 years. Overall, there was a gradual increase in asymmetry from 0.75mm at the symphysis to 2.75mm at the angle, males had less asymmetry than females, and the eldest patients (age >51) had the least asymmetry at the angle (2.0mm).
Conclusions: This study demonstrates a reasonable degree of symmetry between each side of the hemimandible, and suggests that a mirrored hemimandible template may be a useful tool for improving the process of shaping of a recon bar to a 3D printed mirrored hemimandible template.