Ischemic osteonecrosis (second molar region; 58 y/o male). Large cortex-to-cortex cavitation (right) has tough, irregular, leathery walls.  Residual fatty marrow (left) has a diffuse brownish discoloration with scatter smaller cavitations; this tissue was extremely mushy.  Inferior alveolar nerve on left is lightly discolored and somewhat delaminated.  Large area of irregular ischemic osteosclerosis (bone scar; condensing osteitis) is seen in upper center; the dense bone was viable with a fibrous stroma.  Used with permission from: Adams WR et al. J Oral Pathol Med 1999; 28:423-432.