Compare the accuracy and performance of two different types of CAD-CAM surgical guides for maxillary positioning in orthognathic surgery

Abstract

Three-dimensional computer-aided design/manufacturing (CAD/CAM) maxillary guides have been developed to enhance surgical predictability, reducing mandibular interference and improving planning accuracy, especially in asymmetrical cases. This study aimed to compare the accuracy of two types of CAD/CAM guides used for maxillary positioning in orthognathic surgery. In this retrospective cohort study, 38 patients who underwent bimaxillary orthognathic surgery by the same surgeon were divided into two groups. Group 1 (n = 21) used a tooth-bone-supported guide with dual functionality for maxillary positioning and osteotomy. Group 2 (n = 17) used a bone-supported guide combined with pre-modeled titanium miniplates for osteotomy and drilling. Four fixed anatomical points (one bone and three dental) were marked preoperatively and postoperatively to assess 3D maxillary movement along the mediolateral (X), anteroposterior (Y), and vertical (Z) axes. The primary outcome was the precision of maxillary positioning, assessed by overlapping preoperative virtual planning and postoperative cone-beam computed tomography (CT) images. Quantitative differences in millimeters between the planned and achieved positions were measured for all points and axes. The groups were compared using Student's t-test (p < 0.05). Results showed that both groups achieved mean discrepancies of less than 1 mm across all points and axes. No significant differences in accuracy were observed between the two systems (p > 0.05). These findings suggest that both CAD/CAM guide systems provide high precision in maxillary positioning, offering reliable options for orthognathic surgeries based on surgeon preference.