Surgery first approach in orthognathic surgery is to proceed the orthognathic surgery without preoperative orthodontic treatment. This approach has many advantages, which include a shorter total treatment period, a high level of patient satisfaction due to immediate post-surgical facial improvement, easy postoperative orthodontic treatment due to early normalization of skeletal muscle, and the rapid tooth movement reflecting the regional accelerated phenomenon. However instability due to transient occlusal interference after surgery make worse of long-term skeletal stability. Especially increasing of vertical occlusion caused by interference of interbicupid and molar happen postsurgical skeletal change. Until now, there is no common consensus about treatment protocol of surgery first approach in orthognathic surgery. The purpose of this paper is to introduce our treatment protocol of the surgery first approach and to evaluate indication and limitation with case analysis.