Table 3.

Staging according to the American Association of Oral and Maxillofacial Surgeons and the alleged nonexposed variant

Stage	Description
At risk	Patients treated with bone-modifying agents but without apparent necrotic bone (eg, all asymptomatic patients treated with antiresorptives)
Stage 0	No clinical evidence of necrotic bone but nonspecific symptoms or clinical/radiographic findings
Stage 1	Exposed and necrotic bone, or fistulae that probe to bone, that are asymptomatic with no evidence of significant adjacent or regional soft-tissue inflammation or infection
Stage 2	Exposed and necrotic bone, or fistulae that probe to bone, associated with infection, evident by pain and adjacent or regional soft-tissue inflammatory swelling, with or without purulent drainage
Stage 3	Exposed and necrotic bone, or fistulae that probe to bone, associated with pain and infection, and at least one of the following: (1) pathologic fracture, (2) extra-oral fistula, (3) oral-antral fistula, or (4) radiographic evidence of osteolysis extending to the inferior border of the mandible or floor of the maxillary sinus
Nonexposed variant (not widely adopted)	Presence of otherwise unexplained pain in the jaws, fistula, swelling, mobile teeth, or mandibular fracture diagnosed after excluding common diseases of the jaw known to cause similar manifestations