Amount of bone volume and (width and height):

Will be measured using linear measurements from CBCT after 6 month from implant insertion.

Will be measured using Histometric analysis of bone area percent sampling from recipient site after 6 months.

Augmentation of insufficient bone volume can be brought about by different methods, including, particulate and block grafting materials, Guided Bone Regeneration with or without growth and differentiation factors, ridge splitting, expansion and distraction osteogenesis, either alone or in combination. These techniques may be used for horizontal/vertical ridge augmentation

Autograft is considered as the Gold Standard for bone transplantation and various studies have shown efficacy for it. It is osteogenic, osteoconductive and osteoinductive. Autografts can be derived from extra oral source (iliac crest, ribs) or intraoral source (chin, ramus). They can be used in block or particulate form. Corticocancellous block grafts are preferred because of enhanced revascularization of the cancellous portion, and mechanical support and rigidity of the cortical portion, which ensures optimal ridge augmentation.

Fouad Khoury presented a three-dimensional (3D) reconstruction technique for atrophic ridges and complicated vertical bone defects using mandibular bone block graft "the Gold standard". There are several possibilities for augmentation of bone volume depending on situation, indication and adequate diagnosis; the treatment options can be extended from minimally invasive procedures with locally harvested bone grafts in local anesthesia, to very sophisticated grafting techniques for 3D bone reconstruction with extra oral harvested bone grafts. Khoury reported that his ascending ramus grafts is almost 5 times more than chin grafts

Inclusion Criteria:

• patients with atrophic anterior maxilla
• No intraoral soft and hard tissue pathology
• No systemic condition that contraindicate implant placement
• Both sexes.

Exclusion Criteria:

• Heavy smokers more than 20 cigarettes per day.
• Patients with systemic disease that may affect normal healing.
• Psychiatric problems
• Immunodeficiency pathology, bruxism, stress situation (socially or professionally), emotional instability, and unrealistic aesthetic demands.

control group (modified shell technique) study group (onlay bone graft)