To retrospectively analyze of the clinical characteristics and propose and categorise a new classification for osteoradionecrosis of the jaws (ORNJ) .

A total of 507 ORNJ cases surgically treated from March 1993 to October 2014 at the Affiliated Hospital of Stomatology, Sun Yat-sen University were enrolled. Using the proposed "TB" classification based on the damage degree of the soft tissue and jaws, the lesions were defined and categorized. The groups of "TB" definition based on their clinical characteristics were analyzed and correlated to treatments, therapeutic effects and prognosis.

According to "TB" classification, 55 (10.85%) cases were in stageⅠ, 174 (34.32%) , 180 (35.50%) , and 98 (19.33%) cases were in stageⅡ, Ⅲ, and Ⅳ, respectively. Sequestrum scaling, extensive sequestrum resection, or partial ostectomy was performed for patients with stageⅠand stageⅡlesions. For stageⅢand Ⅳ lesions, segmental ostectomy with or without simultaneous vascularized tissue flap, was adopted. In follow-up period, satisfied results have been achieved. The most frequent complications were surgical site infection (19.92%) and wound dehiscence (13.41%) . Severe complications including flap necrosis, aspiration pneumonia and death. The incidences of complications in patients with stageⅠ, Ⅱ, Ⅲ, and Ⅳ were 9.09%, 25.86%, 30.00% and 53.06%, respectively.

We established a "TB" classification based on damage degree of the soft tissue and jaw, and this classification was helpful for making treatment strategy and prognosis evaluation of ORNJ.