J Oral Maxillofac Surg 67:1628-1639, 2009 Accuracy of Computer Programs in Predicting Orthognathic Surgery Hard Tissue Response Neelambar Kaipatur, DMD, MSc,* Yousef Al-Thomali, BDS, Cert Ortho,† and Carlos Flores-Mir, DDS, DSc, FRCD(C)‡ Purpose: The aim of this systematic review was to investigate the accuracy of computer programs in predicting skeletal changes after orthognathic surgery. Materials and Methods: A systematic computerized database search was conducted with the help of a health sciences librarian. Specific selection criteria were used to select articles, reference lists of the selected articles were also searched for any potential articles that might have been missed in the electronic search, and additional information not available through the articles was obtained directly from the corresponding author. Results: Of the 79 initially identified articles (abstracts/titles), only 9 fulfilled the final selection criteria. As expected, no dental changes occurred but the computer programs were unable to precisely predict all the skeletal changes. Most of the prediction inaccuracies were within 2 mm or 2°, which can be partially attributed to measurement errors in cephalometric tracing. Conclusions: This systematic review showed that computer programs cannot consistently predict the skeletal changes occurring after orthognathic surgery but their results may be considered inside a clinically acceptable range. Last-minute changes by the surgeons could also explain the differences. We also conclude that no software program was shown to be superior in prediction accuracy compared with its competitor. © 2009 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 67:1628-1639, 2009 Computer technology has invaded almost every as- pect of human life in recent years. Dentistry in gen- eral and orthodontics in particular are no exception. The use of computers made early inroads into dental research starting in the early 1970s. 1 Orthodontists initially used computer technology for digitization of cephalometric radiographs for orthodontic diagnosis and treatment planning. 2 The pioneering work of Ricketts 2 on computerized cephalometrics not only dealt in great detail with the use of cephalometric radiographs for orthodontic diagnosis, treatment planning, and growth prediction but also researched its use for orthognathic surgery. 3 Orthognathic surgery involves diagnosis, treatment planning, and correction of maxillomandibular defor- mities. During the 1970s, surgeons and orthodontists relied on thorough clinical examination, profile pho- tographs, freehand alteration of lateral skull radio- graph tracing, freehand surgical simulation based on cut-and-paste profile cephalometric tracings, and mock surgery for accurate treatment planning. 4,5 Such techniques were time-consuming and lacked accuracy because of human error involved in tracings and distortion in radiographic images. 5 In addition, these techniques were not able to accurately predict or allow the patient or surgeon to preview the out- come of the treatment. 5 Visualized treatment objectives (VTOs) are impor- tant predictive tools to visualize and predict treatment goals before, during, and at the end of treatment. 6 Computerized VTOs allow the use of various software *PhD Candidate, Graduate Orthodontic Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada. †Senior Registrar Orthodontist, Prince Mansour Military Hospital, Taif, Kingdom of Saudi Arabia. ‡Associate Professor, Graduate Orthodontic Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada. Dr Flores-Mir is supported by an American Association of Orth- odontics Foundation teaching award (2007 Eugene E. West Memo- rial Fellowship Award). Address correspondence and reprint requests to Dr Flores-Mir: Department of Dentistry, University of Alberta, 4051A Dentistry/ Pharmacy Centre, Edmonton, Alberta, Canada T6G 2N8; e-mail: carlosflores@ualberta.ca © 2009 American Association of Oral and Maxillofacial Surgeons 0278-2391/09/6708-0009$36.00/0 doi:10.1016/j.joms.2009.03.040 1628