Introduction: Mandibular osteomyelitis is said to occur commonly following odontogenic infections and trauma. However, there is minimal literature available which discuss its occurrence after orthognathic procedures like Bilateral Sagittal Split osteotomy. Patient complaint: Wound dehiscence and bone exposure. Diagnosis, Intervention and outcomes: OPG revealed radiolucency of size 1.5*1 cm below the root apices of 46,47 . CT revealed osteomyelitic changes in the same region .. Sequestrectomy was done and resorbable collagen membrane was placed . The decalcified histopathological section revealed necrotic bone in a loose stroma surrounded by moderate inflammatory cell infiltrate composed mainly of lymphocytes and absence of osteoblastic cells in the periphery , suggestive of