Lateral Cephalogram with analysis and tracing of facial profile.

Modified model surgical tecnique:

1. Obtain wax bite registration.
2. Record face-bow transfer.
3. Duplication of articulating model for surgical simulation.
4. Measure all casts and bases in standard model surgery fashion.
5. Fabricate intermediate splint & Final splint.
6. Condylar repositional splint.

Preoperative surgical simulation and immediate postoperative evaluation will be carried out using Multi Slice CT scan.

Computer-aided planning for study group:

All planning will be done using specialized software (Anatomage Invivo 5.3) for preoperative surgical simulation and immediate postoperative evaluation.

Pre-operative Fabrication of computer aided surgical splint:

In the study group a stereo splint will be fabricated using rapid prototyping (RP) technique to guide the osteotomy and another one will be fabricated after virtual osteotomy to guide the surgical cuts. And stent for guided holes.

So that the osteotomy will be accomplished by the aid of computer guided templates that simulates the proper bite achieved preoperatively during surgical simulation and Planning.

Preoperative surgical simulation and immediate postoperative evaluation will be carried out using Multi Slice CT scan.Craniofacial images from 3D computerized tomography (3D-CT scan) can be used to create a 3D model, which can in turn be used for 3D Cephalometry measurements and surgical simulation.The process of 3D-model contains mounting of 3D virtual models in a 3D virtual articulator; and repositioning of 3D virtual models according to the STO then Fabrication of a 3D virtual intermediate surgical wafer; and materialization of the surgical wafer using a stereolithographic technique. The 3D model can produce actual movement of surgical cuts and movement of segments accordingly

Computer guided Super-imposition of virtual surgery over the post- operative CT Scan composite models (millimeter mm).

Conventional Super-imposition of scanned articulator with mounted casts in the pre-planned mock surgery over post-operative scanned mounted occlusion- accuracy would be compared by difference between Intervention and control in (millimeter mm).

Standardized pre-surgery movement in amount of anterior open bite closure (mm) will be determined clinically and by radiograph.