Computer-guided rapid-prototyped templates for segmental mandibular osteotomies: a preliminary report.

Background: Segmental mandibular resection represents a challenge to maxillofacial surgeons in terms of accurate contouring of reconstruction plates, restoration of mandibular symmetry and maintaining accurate condylar position in the glenoid fossae.

Methods: We propose a CAD/CAM technique for fabricating patient-specific templates to symmetrically prebend reconstruction plates, guide osteotomies and reposition the condylar process in the proximal edentulous segment in its preoperative position. We operated on two patients using this new technique.

Results: The custom-made templates showed excellent passive fit on the respective mandibles and accurately guided the reciprocating saw blade along the resection margins. The template was also capable of maintaining the spatial relation of the resected mandibles and the patients experienced excellent repeatable occlusion. Superimposition of pre- and postoperative cone-beam CT scans showed restoration of mandibular symmetry and maximum deviation of 0.4-1.4 (mean of 0.9) mm from the preoperative condylar position. The achieved resection margins using the template showed a mean distance of 1.17 mm from the virtually planned ones.

Conclusion: We present an innovative computer-guided template that allowed for accurate guidance of mandibular resection margins and condylar positioning. The technique needs to be applied in a larger cohort of patients to verify the results. Further modifications of the design and rigidity of the template might proof beneficial.