All patients undergo surgical necrotic bone debridement in combination with antibiotic therapy (clindamycin 300 mg q8h) for 4 weeks . Patients who had BRON of the mandible randomly allocated in 2 groups. Group 1 underwent debridement of necrotic bone and the involved area closed primary and in group 2 ,patients received topical Phenytoin 5%+ Tetracycline. Patients were evaluated after 1(time1) ,6(time2) and 12(time 3) months.