['To evaluate the clinical values of alveolar ridge augment of atrophic posterior mandible using modified sandwich technique with immediate implantations,', 'Three patients with atrophic posterior mandible were enrolled in this study. A sandwich osteotomy was performed using a piezosurgery device, and 2 submerged implants were placed in approximal locations simultaneously to support and stabilize the osteotomy segments. Some xenografts were inserted into sandwich region and a GBR membrane was applied during operations. After 6 months, definitive prostheses were completed.', "No dehiscence of the mucosa was observed in all patients. 2 patients' swelling gradually disappeared after a therapy with antibiotics and dexamethasone for 3 days. Six months later, newly formed bones were observed near the osteotomized segments, and peri-implant area showed osseointegration. The mean height of augmentation was about 5mm."] Do [ Clinical application of alveolar ridge augment of posterior mandible using modified sandwich technique with immediate implantations ]?