Mandibular Deficiency

Objective: to evaluate the dentoskeletal effects of CAD/CAM 3D-Printed fixed twin block versus MARA appliances in the management of skeletal class II due to Mandibular Deficiency in Preadolescence Class II malocclusion is considered one of the most commonly observed problems among orthodontic patients, representing around one-third of the patients seeking orthodontic treatment reflecting a significant economic impact. Various removable and fixed functional appliances are commonly used to stimulate mandibular growth. Fixed Twin-block appliance has advantages compared with removable Twin-block and Herbst appliances. The mandibular anterior repositioning appliance is referred to as M.A.R.A. appliance. Materials and method: The study design is a randomized controlled trial in which the control group and intervention groups will be assessed as parallel groups with a 1:1:1 allocation ratio. Sixty subjects will be enrolled in this research. They will be divided equally into three groups: untreated control, MARA group and Twin block group

* 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 )

Mandibular reconstruction is necessary following trauma, tumour resections and extensive infections resulting in severe defects of the mandibular arch. For reconstructing large and recurrent defects, the vascularized free flaps are currently regarded as the gold standard. The use of these flaps, however, presents several major inconveniences. Although regenerative medicine in the field of cranio-maxillofacial reconstruction has now become a common practice, the main technical challenge is still related to vascularization of the regenerated tissue in large defects. Axial vascularization of constructs using a microvascular arteriovenous fistula/loop (AV loop) aims at providing the construct with blood supply through a defined and dedicated vascular axis. This technique was successfully demonstrated in some case reports, but was never applied in the craniofacial region. The current study aims to apply and assess the technique of axial vascularization using the AV loop of a bone substitute to reconstruct mandibular defects.