A Comparison of Traditional Model Surgery and Virtual Surgical Planning for Accuracy in Le Fort I Osteotomies

摘要

Maxillary surgeries have been performed since the 1940's. Historically, these treatments were planned using plaster models, lateral cephalometrics, postero-anterior cephalometrics, and hand-fabrication of occlusal splints by the orthodontist or surgeon. Treatment planning was done in two-dimensions (2D) and extrapolated into a 3-dimensional plan. With new digital and technological advances, plans can be constructed in three-dimensions (3D) using cone beam computed tomography (CBCT) scans, digital intraoral scans, computer aided simulation, and computer aided fabrication of splints. It has been suggested that this new form of virtual surgical planning (VSP) yields more desirable results. However, accuracy of surgical outcomes from traditional planning versus computer simulations needs to be quantified. The aim of this study was to compare the accuracy of traditional versus VSP in patients having Le Fort I osteotomies. This information was used to assess how accurate the pre-surgical planning, using either method, was in achieving the resultant outcomes of the surgery.;Fifty treated patients who required maxillary surgery were included in this study. Twenty-five were treated with traditional 2D information used for treatment planning, while twenty-five were treated with computer simulated treatment planning (Medical Modeling). Pre and post treatment CBCT scans were obtained for both groups. Each scan was analyzed using Anatomage's Invivo5 Advanced 3D imaging software.;The difference between the planned and actual movements of both modalities was summed and rank ordered. The top 15 most predictable movements, and 85% of the top 20 were all accomplished with virtual surgical planning. Conversely, the last 11 least predictable movements were produced using the traditional method. There were significant differences between planned and actual outcomes for all 8 landmarks of interest in the traditional planning. Conversely, for the VSP, 11 of the 21 were not significantly different.;Overall, the results support our hypothesis that 3D VSP is significantly more accurate in achieving the desired surgical movement for almost all landmarks measured in this study compared with traditional model surgery and 2D planning. Additionally, the data in this study supports previous findings that landmarks such as A point, anterior nasal spine, and upper central incisors in the maxilla are more predictable in achieving the desired post-surgical position than other landmarks, and should be considered when planning future surgeries.