Analysis of simulated mandibular reconstruction using a segmental mirroring technique.

Area of Science:

• Oral and Maxillofacial Surgery
• Biomedical Engineering
• Medical Imaging

Background:

• Mandibular reconstruction often faces challenges due to bone deformity limiting intraoperative plate adaptation.
• Three-dimensional (3D) models offer a potential solution by digitally mirroring unaffected bone segments.
• The segmental mirroring technique involves creating an inverted image of a contralateral mandibular segment to adapt a reconstruction plate.

Purpose of the Study:

• To evaluate the accuracy of the segmental mirroring technique for generating 3D models in mandibular reconstruction.
• To assess the degree of conformance between mirrored and actual bone segments using 3D analysis.

Main Methods:

• High-resolution computed tomography (CT) scans of mandibles from a melanoma database were segmented into four defect classes.
• A mirrored image of each mandibular segment was digitally created and co-registered with the contralateral segment.
• Conformance analysis was performed using root-mean-square (RMS) distance and 3D conformance maps.

Main Results:

• A high degree of conformance (mean RMS < 1 mm) was achieved across all simulated reconstruction classes.
• Class III simulated reconstructions showed the closest conformance (mean RMS: 0.4 ± 0.2 mm).
• Inclusion of the condyle reduced mean RMS conformance, with less accuracy observed in 3D mapping of the condyle and coronoid process.

Conclusions:

• The segmental mirroring technique reliably generates accurate 3D models for mandibular reconstruction, aiding plate adaptation.
• The technique's accuracy is reduced when mandibular pathology involves the condyle and, to a lesser extent, the coronoid process.