• Patients will be collected from faculty of dentistry
• bilateral vertical ramus osteotomy (VRO )with iliac graft group (group I):- 10 patients will be treated via VRO and iliac crest or
• bilateral sagital spilt osteotomy (BSSO) group (group II):- 10 patients will be treated via BSSO
• All patients will be studied by comprehensive clinical oral and maxillofacial examination and lateral cephalometric radiographic analyses, within 1 week before the surgery (T0), immediately after the surgery (T1), and 6 months after surgery (T2).
• All lateral cephalometric radiographs and clinical photographs must be standardized for all cases.
• After pre-surgical orthodontic treatment , a lateral cephalograph Will be obtained for planning the surgical movement of both jaws
• Surgical models and surgical stent will be fabricated.
• All surgical procedures will be performed under nasal intubation and general anesthesia to surgically reposition the maxilla in standard LeFort I setback fosteotomy; the BSSO group will be underwent BSSO, and VRO group will be underwent VRO
• The bony segments will be fixed in the new position with the use of custom made plates (specific for each patient )

Inclusion Criteria:

• patients with age above 18 years old suffered from skeletal class II with severe mandibular deficiency

Exclusion Criteria:

• patients with chin deviation,
• severe temporomandibular joint (TMJ) symptoms.
• Sever periodontal disease
• pregnancy,
• previous mandibular surgery,
• inability to follow-up for the study protocol