The patients in the test group receives BFPSCs loaded on FDBA with PRF for posterior mandible augmentation and the control group receives combination of PRF and FDBA (lacking any cells). The BFPSCs+FDBA+PRF in the test group and FDBA+PRF in the control group are placed in the gap between the block graft and recipient site. The results will be evaluated by cone beam computed tomography (CBCT) in 6 months and microscopic evaluation of the biopsies by hematoxylin and eosine staining during implant placement.