Objective:To investigate the clinical outcomes of sublingual gland flap in the repair of postoperative jaw defects because of chronic phosphorous osteomyelitis(PNJ)and medication-related osteonecrosis of the jaw(MRONT).Methods:3 patients with PNJ and 2 with MRONJ were treated by sublingual gland flap in the repair of the postoperative jaw defet.The treatment effects were evalua-ted by clinical obseration.Results:In the 5 patients the wound healed well within 2 weeks postoperatively,with no infection and with normal sublingual gland function after surgery.Conclusion:The use of sublingual gland flap is an effective and feasible method for re-pairing local defects in the mandibles after surgery for chronic PNJ and MRONJ.