The bilateral sagittal split Ramus osteotomy (BSSRO) was introduced by Trauner and Obwegeser. Since then, many modifications of this procedure have been reported, leading to a less difficult and more predictable procedure for correcting mandibular anomalies. persistent post-operative neurosensory disturbances of the inferior alveolar nerve are still one of the major complications of this operation. The incidence has decreased over the years due to improved techniques and the use of different instruments. However, most recent series still report postoperative persistent hypesthesia of the inferior alveolar nerve in more than 10% of the patients up to 48%.

There are no reports on the influence of other surgical variables on the persisting post-operative hypesthesia. Several methods have been reported for evaluating neurosensory disturbances of the inferior alveolar nerve. One of the simplest methods reported is tactile evaluation based on subjective sensation reported by the patients. Many authors have used this method in their evaluation of post-operative hypesthesia.

IInclusion criteria:

1. Patient with skeletal malocclusion, class II or class III that is indicated for bilateral sagittal split osteotomy.
2. Adults >18 years.
3. Systemically healthy.

Exclusion criteria:

1. Patients not indicated for orthognathic surgery.
2. Severe systemic disease.
3. Have a medical condition associated with systemic neuropathy (e.g. diabetes)
4. Patients whom cannot tolerate follow up intervals. (affect accuracy of study results)
5. Are unwilling to sign informed consent.