Intraoral vertical ramus osteotomy.

: In corrective surgery for mandibular prognathism, the vertical ramus osteotomy, also known as the vertical subsigmoid osteotomy (VSS) is one of the simplest osteotomy to perform and therefore widely popular with oral & maxillofacial surgeons. Traditionally, the surgical approach for VSS is by the extra-oral approach although the approach may be either extraoral or intraoral. In this paper, the main advantages and disadvantages of the following three techniques, i.e. VSS via extraoral approach, VSS via intraoral approach and the sagittal split ramus osteotomy will be discussed. The vertical ramus osteotomy via the intraoral approach is not usually performed in Singapore until recently. The authors would like to present the observations and a surgical technique employed by them to perform VSS osteotomy via an intraoral approach.