It is generally known that sagittal split ramus osteotomy (SSRO) has greater postoperative stability than intraoral vertical ramus osteotomy (IVRO); however, inferior alveolar nerve (IAN) damage is likely to occur. On the other hand, IVRO has problems with slow postoperative osseous healing and projection of the antegonial notch; however, it is believed that IAN damage is unlikely to occur. The purpose of this study is to compare the osseous healing process of SSRO with IVRO. On the CT image, the SSRO osseous healing process was almost the same as that of IVRO. Projection of the antegonial notch occurred after IVRO, but returned to the preoperative state within half a year of the operation. IVRO postoperative IAN damage did not occur, and the osseous healing process was similar to SSRO. Therefore, it was shown that IVRO is as good an operational procedure for mandibular protraction as SSRO.
