Inclusion Criteria:  Patients will have a posterior mandibular atrophic ridge Distance between the crest of the ridge and the superior border of the inferior alveolar canal will be from 5 mm to 7 m Adequate inter-arch space  Exclusion Criteria:  Patients who have any uncontrolled systemic disease contraindicated to oral surgery ( Diabetes, hypertension, and patients under chemotherapy treatment ) Patients who have any relevant bone disease. Patients who are smokers