The purpose of this study is to assess the accuracy and clinical validation of patient specific implants (PSI) technique for genioplasty.

Chin plays an important role in the lower facial harmony and balance. With the advances in computer-aided surgical simulation (CASS) technology, surgeons are now able to simulate surgical procedures in the computer to achieve the best possible surgical plan. However, CAD/CAM surgical templates do not maximize the potential of CASS technique. Patient specific implants (PSI) has rapidly developed in cranio-maxillofacial surgery in the past few years. However, few studies have introduced PSI technique in osseous genioplasty. The purpose of this study is to assess the accuracy and clinical validation of patient specific implants (PSI) technique in genioplasty for positioning and fixation of the chin segment.

Anticipated 30 patients with chin deformities are enrolled. Virtual planning is performed with the computer-aided surgical simulation method. The 3D printing titanium cutting guide and patient specific plate is involved in this PSI method. The cutting guide is designed to guide the osteotomy and screw holes drilling for the following patient specific plate. And the patient specific plate is used to simultaneously complete the reposition and fixation of the chin. The outcome is evaluated by comparing the plan with actual outcomes.

Inclusion Criteria:

1. patients who were scheduled to undergo genioplasty;
2. patients who were scheduled to undergo CT scan as a part of their diagnosis and treatment;
3. patients who agreed to participate in this study

Exclusion Criteria:

1. craniofacial syndrome;
2. segmental osseous genioplasty;
3. previous osseous genioplasty;
4. previous mandibular trauma;
5. systemic disorders.