Modification of the sagittal split ramus technique

Abstract

Many modifications and variations of the original sagittal split procedure have been performed since its inception. Many of these procedures do not involve the full width of the ascending ramus in an attempt to reduce blood loss and nerve damage. These risks of damage can be reduced by using the technique and instrumentation described, while at the same time the surgeon is allowed use of the full width of the ascending ramus. The surgical splitting of the ascending ramus of the mandible in the sagittal plane was first described by Obwegeser in 1957.’ Dal Pont2 described his modification of Obwegeser’s technique in 1961. Since then many modifications and approaches have been published.3-6 Common complaints from surgeons about the sagittal splitting procedure include an extended length of operating time, an increased risk of injury to the inferior alveolar nerve, excessive bleeding and edema, infection, and relapse. Comparisons between the sagittal split and other techniques,7 however, have shown little difference in postoperative problems except for an increased incidence of inferior alveolar nerve damage and greater volume of blood loss with the sagittal ramus split technique. Most modifications of the Obwegeser procedure represent attempts to negate the aforementioned difficulties with the original technique. Inability to achieve good visibility increases the difficulty of the procedure, thereby increasing the risk of damage to the inferior alveolar nerve and artery. This represents a major cause of increased operative bleeding and postoperative paresthesia. Epke$ believed that operating distally to the lingula caused additional nerve damage, and he therefore used essentially a Hunsuck modification. In correction of simple prognathism, the vertical ramus osteotomy and the Hunsuck modification generally provide adequate bony contact. In correction of retrognathism, apertognathism, or prognathism with an open bite component, however, the Hunsuck modification may not result in an adequate