This book describes a new method of correcting midfacial nasomaxillary deformities that entails the use of just a single intraoral incision: Intraoral Le Fort II Osteotomy (Choung’s 9 Osteotomy). The fundamental surgical procedures are explained in detail, with each principal stage in the method being addressed in a separate chapter. In order to assist the reader in fully understanding the technique, a wealth of intraoperative color photos are included, as well as radiographs, 3D CT images, computer images and examples of 3D RP models. In addition, the book introduces Intraoral Le Fort II and I Combined Osteotomy (Choung’s 9-1 Osteotomy) and presents new distraction concepts and techniques of Intraoral Le Fort II Osteotomy. Le Fort II osteotomy is indicated in patients with nasomaxillary deficiency, deformity, or asymmetry and is most commonly employed in Asians. Its use was in the past limited by the lack of an intraoral approach, but the method presented in this book is reproducible, stable and safe, as proven by long-term follow-up over 20 years. This book is designed for maxillofacial surgeons and residents, as well as others with an interest in the field.