A 27-year-old female was referred to our hospital postpartum due to rapid aggravation of facial swelling. She was diagnosed with osteomyelitis on clinical, radiological, and histopathological examinations, but the possibility of malignancy was not excluded. Clinical signs and symptoms such as facial swelling and discomfort were improved with four months of antibiotics treatment. This is as case of an osteomyelitis progressed from infected extraction socket in a woman with physiological changes of pregnancy. Decreased immunological response, increased sex hormone and calcium regulatory hormones regulate the response of the bone infection. We report this case for helping the diagnosis of unusual from of osteomyelities in pregnancy and postpartum.