Virtual planning and 3D-printed guides for mandibular reconstruction: Factors impacting accuracy

Area of Science:

• Oral and Maxillofacial Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Mandibular reconstruction presents challenges in achieving accurate anatomical restoration.
• Virtual surgical planning (VSP), 3D printed guides, and pre-bent reconstruction plates offer a potential solution.

Purpose of the Study:

• To evaluate the accuracy of mandibular reconstruction using VSP, 3D printed osteotomy guides, and preoperatively bent reconstruction plates.
• To identify factors influencing the accuracy of this technique.

Main Methods:

• A retrospective review of 60 free-flap mandibular reconstructions using VSP/3D-printed-guide/plate from 2015-2020.
• Accuracy assessed via 3D model overlay, cephalometric analysis, and donor-bone segment length measurements.
• Multivariate analysis to determine factors affecting accuracy.

Main Results:

• Reconstructions showed minimal deviation: intercondylar distance 2.10mm, intergonial distance 2.23mm, APD 1.76mm, gonial angle 3.11 degrees.
• Increased donor-bone segments correlated with decreased gonial angle accuracy (p=0.023).
• Longer donor-bone length correlated with decreased anterior-posterior distance accuracy (p=0.031).

Conclusions:

• This study represents the largest series evaluating the surgical accuracy of VSP/3D-printed-guide/plate for mandibular reconstruction.
• The technique demonstrates high accuracy, supporting its reliability.
• Factors such as the number of donor-bone segments and donor-bone length can impact accuracy.