Two groups with mandibular prognanthism indicated for mandibular setback by intraoral vertical ramus osteotomy . first group will fixed with maxillomandibular fixation and the second group will fixed by customized plate

Two groups with mandibular prognanthism indicated for mandibular setback by intraoral vertical ramus osteotomy . first group will fixed with maxillomandibular fixation and the second group will fixed by customized plate

Interventions:

General operative procedures

Eligible patients will be randomized in equal proportions between the study group (customized plate fixation of VRO) and the control group (maxillomandibular fixation of VRO).

Patients of Both groups will be subjected to:

1. Case history including personal data, medical, surgical history and family history
2. Clinical examination .
3. Radiographic examination in the form of cephalometric radiogragh .
4. Preoperative laboratory tests (complete blood cell count, Hemoglobin count, coagulation profile, liver function, kidney function and blood glucose level).
5. Preoperative anesthesia assessment for fitness for general anesthesia.

vertical ramus osteotmy fixed with customized plate

• All cases will undergo one surgery under general anesthesia.
• Incision was made medial to external oblique ridge from the asendindg ramus to second molar region
• Amucoperiosteal flap was reflected to expose the lateral mandibular ramus to the posterior border and the sigmoid notch
• The intraoral vertical osteotomy is accomplished by using an oscillating saw to make the cut from the sigmoid notch through the inferior border of the mandible. The osteotomy is placed 5 mm anterior to the posterior border of the mandible to avoid injury to the inferior alveolar neurovascular bundle
• 3D virtual planning and 3D mandible model represented fom CBCT in MIMICS
• The setback will be simulated according to pre-planned measure
• The customized bone plate is positioned to fix the proximal and distal segment together

vertical ramus osteotomy fixed with MMF.

• All cases will undergo one surgery under general anesthesia.
• incision was made medial to external oblique ridge from the asendindg ramus to second molar region .
• Amucoperiosteal flap was reflected to expose the lateral mandibular ramus to the posterior border and the sigmoid notch
• The intraoral vertical osteotomy is accomplished by using an oscillating saw to make the cut from the sigmoid notch through the inferior border of the mandible. The osteotomy is placed 5 mm anterior to the posterior border of the mandible to avoid injury to inferior alveolar neurovascular bundle.
• Patient is placed in maxillomandibular fixation (MMF) using a prefabricated occlusal splint to assure accuracy of the mandibular position.

follow up clinical and radiographic evaluation will be performed at the first week postoperative then the patients will recalled for radiograghic evaluation at 2weeks and 2 months .finall follow up visit will be at 6 months postoperative

Inclusion Criteria:

All subjects were required:

• Patients with mandibular prognanthism indicated for mandibular setback.
• All ages >18 years
• Patients should be free from any systemic disease that may affect normal healing of bone, and predictable outcome.
• Patients with good general condition allowing surgical procedure under general anesthesia.
• Patients with physical and psychological tolerance

Exclusion Criteria:

• History of mandibular trauma
• Previous orthognathic surgery
• Degenerative disease of temporomandibular joint
• Craniofacial syndrome such as cleft lip or palate
• Follow up period will be less than 6 months