Mandibular reconstruction using computer-aided design and computer-aided manufacturing: an analysis of surgical results

Abstract

Purpose: The purpose of this study was to analyze the accuracy of virtual surgical planning in mandibular reconstruction.

Materials and methods: This is a retrospective study involving 8 consecutive patients reconstructed with nonvascularized iliac crest bone grafts and free fibula osteomyocutaneous flaps. DICOM data from a maxillofacial skeleton computed tomography (CT) scan were sent to a medical modeling company and used to map the mandibular resection, anatomically place the mandibular reconstruction plate, and create surgical guides. After surgery a postoperative CT compared the virtual plan to the surgical result. Linear measurements [2 transverse and 1 anterior-posterior (A-P)] were performed to determine if the virtual surgical result was achieved. The transverse measurements were made from the condylar head to condylar head and from the gonial angle to gonial angle. The A-P analysis was made by measuring a perpendicular line drawn from the anterior inferior mandibular border to the center point on the condylar head to condylar head measurement.

Results: The average surgical error in the A-P dimension for the iliac crest bone grafts and free fibula flap was 0.2 mm (range 0.0 mm to 0.7 mm) and 0.9 mm (range 0.2 mm to 1.9 mm), respectively. In the transverse dimension the average surgical error was 1.6 mm (range 0.7 mm to 2.4 mm) and 2.7 mm (range 1.9 mm to 4.5 mm) from condyle to condyle, and 1.7 mm (range 0.7 mm to 2.7 mm) and 2.5 mm (range 0.4 to 4.8 mm) from gonial angle to gonial angle.

Conclusion: The use of CAD-CAM (Medical Modeling, Golden, Colorado) technology for the fabrication of surgical resection guides and mandibular reconstruction plates resulted in an accurate surgical result.