Alveolar reconstruction of bony defects in cleft lip and palate patients is an essential step in the overall management of a patient with cleft lip and palate. Many sources of both autogenous and alloplast bone grafts have been studied and compared in the search for the ideal bone graft material. In this study, twelve patients with unilateral maxillary alveolar clefts were selected and divided randomly into two equal groups; Group (A) grafted with mandibular symphyseal bone graft and β-tricalcium phosphate. Group (B) grafted by using autogenous mandibular symphyseal bone graft. Cone beam CT-scans taken and volumetric analysis performed to evaluate the volume of the alveolar cleft grafted. Statistical analysis showed no, statistically significant difference in the volume of bone formed in the two groups. We concluded that mandibular symphyseal bone grafts mixed with β-TCP granules can be used successfully in cases in which the alveolar cleft is too large to be grafted with mandibular symphyseal bone graft alone.