Custom-Machined Miniplates and Bone-Supported Guides for Orthognathic Surgery: A New Surgical Procedure

Purpose: Several surgical strategies exist to improve accuracy in orthognathic surgery, but ideal planning and treatment have yet to be described. The purpose of this study was to present and assess the accuracy of a virtual orthognathic positioning system (OPS), based on the use of bone-supported guides for placement of custom, highly rigid, machined titanium miniplates produced using computer-aided design and computer-aided manufacturing technology.

Materials and methods: An institutional review board-approved prospective observational study was designed to evaluate our early experience with the OPS. The inclusion criteria were as follows: adult patients who were classified as skeletal Class II or III patients and as candidates for orthognathic surgery or who were candidates for maxillomandibular advancement as a treatment for obstructive sleep apnea. Reverse planning with computed tomography and modeling software was performed. Our OPS was designed to avoid the use of intermaxillary fixation and occlusal splints. The minimum follow-up period was 1 year.

Results: Six patients were enrolled in the study. The custom OPS miniplates fit perfectly with the anterior buttress of the maxilla and the mandible body surface intraoperatively. To evaluate accuracy, the postoperative 3-dimensional reconstructed computed tomography image and the presurgical plan were compared. In the maxillary fragments that underwent less than 6 mm of advancement, the OPS enabled an SD of 0.14 mm (92% within 1 mm) at the upper maxilla and 0.34 mm (86% within 1 mm) at the mandible. In the case of great advancements of more than 10 mm, the SD was 1.33 mm (66% within 1 mm) at the upper maxilla and 0.67 mm (73% within 1 mm) at the mandibular level.

Conclusions: Our novel OPS was safe and well tolerated, providing positional control with considerable surgical accuracy. The OPS simplified surgery by being independent of support from the opposite maxilla and obviating the need for classic intermaxillary occlusal splints.