The in-house designed patient-specific implants combined with navigation systems in orthognathic surgery: a case series of three patients.

Objectives: This case series aims to describe the virtual surgical planning process and report the surgical outcomes of in-house-designed patientspecific implants (PSIs) combined with navigation systems in orthognathic surgery.

Patients and methods: Three patients undergoing two-jaw surgery were assessed across pre-surgical planning, surgical execution, and post-surgical evaluation phases. The accuracy was evaluated between the surgical plan (T0) and immediate post-operative three-dimensional (3D) radiographic image (T1) using 2 methods: bone surface comparison and dental landmark comparison. The stability was assessed between T1 and 3D radiographic image at 9 months after surgery (T2) by Bone surface comparison method.

Results: The accuracy assessed by Bone surface comparison shows that green areas (deviation between 0.0-0.4 mm) were mostly observed in the anterior region of the Le Fort I segment. The average deviations of dental landmark comparison are as follows: in the left-right direction, 0.28±0.41 to the right; in the anterior-posterior direction, 0.13±0.48 to the posterior; and in the superior-inferior direction, 0.37±0.39 to the inferior. The stability assessed by bone surface comparison shows the green area in two of three patients, indicating minimal post-surgical changes.

Conclusion: The in-house-designed PSIs combined with navigation systems can achieve accuracy and stability in orthognathic surgery.