Significance of Inferior Alveolar Nerve in BSSO

The sagittal split ramus osteotomy is now the most widely used orthognathic surgical procedure to correct jaw deformity. Due to the position and course of the mandibular canal, the IAN is at great risk of injury during SSRO. The incidence of immediate postoperative sensory impairment ranges from 49% to 100%. To reduce injuries to the IAN during SSRO, prior knowledge of the anatomic location and course of the mandibular canal is imperative. While there are number of studies on this line on cadavers and dry mandibles, there is hardly any study on the individuals undergoing BSSO. This has prompted us to undertake the present study, that is by assessing the position of mandibular foramen, evaluation of IAN at different levels pre-operatively and interpolating these readings and knowledge intra-operatively. Computer assisted navigation allows for real-time imaging of the surgical drill as an overlay graphic on CT and live intraoperative video images and has been reported to be suitable for routine clinical applications. The pre-operative evaluation of actual course of mandibular canal by means of computer tomography will be of great help to the surgeon in reducing the risk of IAN injury