Three-dimensional repositioning of the maxilla is possible after Le Fort I osteotomy. However, the preoperatively planned and desired position of the maxillary dental arch often cannot be sufficiently achieved during actual surgery, and deviations in the sagittal and vertical dimensions are common. To reduce these errors, the model-repositioning instrument was developed for model surgery in conjunction with the Gottingen concept for orthodon tic-surgical treatment with condylar position control. This instrument allows a controlled three-dimensional positioning of jaw segments with three reference points directly on the teeth. The three-dimensional double-splint method combined with a surgical facebow was developed for a controlled three-dimensional positioning of the maxilla during surgery. This instrument and method were applied during treatment of 20 adult patients, and the position of the maxilla before and after surgery was analyzed. It was found taht the planned position of the maxillary dental arch could be transferred from model surgery to actual surgery with an accuracy of +- 1 mm sagittally and vertically. Thus, the application of the Gottingen concept for three-dimensional positioning of the maxilla results in an improvement of accuracy compared with other methods. Furthermore, use of these procedures is easier and less time-consuiming during model and actual surgery than are other procedures.