Maintaining the condylar position after bilateral sagittal split ramus osteotomy (BSSO) is one of the most important aspects in terms of condylar function ,.An altered condylar position can cause internal derangement of the joint, loss of the mandibular angle, increased risk of relapse, condyle sagging, and impaired masticatory function.

In previous years, a great deal of attention has been paid to maintaining the preoperative condylar position during orthognathic surgery. Numerous condylar positioning methods have been reported and could be divided into manual/empirical methods, conventional methods , navigation, and sonographic monitoring, Computer guided methods which is more accurate than other methods

unpredictable condylar position after orthognathic surgery, will lead to malocclusion, derangement of the condylar surface, condylar resorption, condylar sag, distraction of the condyles from the fosse. In previous years, several authors had been adopted several techniques to maintain the preoperative condylar position during orthognathic surgery. Numerous condylar positioning methods have been reported which could be divided into conventional techniques (manual maneuvers or aiding tools), Extra and intra oral navigational techniques , surgeons had been utilized these techniques in condylar repositiong after BSSO but it was time and effort consuming and sometimes it was inaccurate. the aim for conducting the research is accurate positioning of condyle three dimensionally to minimize effort and operating time of surgery .

Inclusion Criteria:

• Age of the patient above 18 years
• Patients needs bilateral sagittal split osteotomy
• All patients are free from any systemic disease that may affect normal bone healing
• Sufficient dentition to reproduce the occlusal relationships
• Patient's consent to participate

Exclusion Criteria:

• Patient with TMJ Disorders
• Patients with any systemic disease that may affect normal healing
• Intra-bony lesions or infections that may interfere with surgery.the presence of
• Previous orthognathic surgeries