One of the goals of orthognathic surgery is to improve a patient’s function without compromising the health of the dentition or the patient’s esthetics. As the understanding of the complexities of skeletal deformities has evolved and the predictability of surgical procedures has improved, treatment planning has dictated that the best results for many patients can be achieved only by moving both jaws. A careful and methodic approach involving clinical evaluation, cephalometric tracings, model surgery with facebow transfer, and occlusal splints is necessary to ensure the accuracy of the surgery and predictability of the result. Upper airway changes following bimaxillary advancement surgery to treat obstructive sleep apnea syndrome remain controversial. However, bimaxillary advancement surgery has been shown to be beneficial in terms of increased upper airway size, improved oximetric indicators, and the quality of life measured on the Epworth sleepiness scale.