Precise Prediction of Transitional Occlusion Using Reverse Engineering in Surgery-first Orthognathic Surgery Case

With surgery-first approach, the skeletal discrepancy is corrected with orthognathic surgery at the start of treatment, but the teeth remain in their original compensated positions. This change in treatment sequence means clinicians have to determine what the occlusion immediately after the surgery, which is called transitional occlusion, should look like during the planning process. This report describes the surgical and orthodontic planning for a surgery-first case that corrected a large Cl III malocclusion. Virtual planning was used to reverse engineer the transitional postsurgical occlusion from the final ideal position. A multiplatform software can be a powerful tool for analyzing problems in finishing a surgery-first case, predicting outcomes, and improving the accuracy in planning surgery-first approach.