Ischemic osteonecrosis, multifocal (molar/bicuspid region; 53 y/o male with atypical facial neuralgia). Brown/black, multicystic area of mushy marrow necrosis is seen beneath cortex of first molar region.  Inferior alveolar nerve is surrounded by semitranslucent gray material (gelatinous marrow) and the bony canal is largely destroyed.  A linear cavitation is seen just above the inferior cortex.  Gray/brown area on the left margin is old NICO surgery site (cuspid area) with healed poorly with dense fibrous scar and scattered hemosiderin deposition.

Radiograph of previous case shows a subtle honeycombed radiolucency in the subcortical region of greatest disease, but without tenderness in the site, which was the case here, this most likely would be considered a "normal" bone.  Unlike other x-rays in this series, this is a periapical radiograph taken prior to the death of the patient, while in other cases the films were made from cadaver research mandibles.

Ischemic osteonecrosis of angle (ramus & molar region of mandible; 65 y/o female). Mushy discoloration of large area of the angle of the mandible (left) was predominantly necrotic, while the less discolored and less mushy anterior lesion (molar area) was bone marrow edema (central area, above the inferior border).  The inferior alveolar nerve appears normal.

Ischemic osteonecrosis of angle. Radiograph of previous case shows mild and diffuse radiolucency of the posterior/inferior ramus, but changes are so subtle that this would most likely have been read as "normal" bone.

Bone marrow edema (first molar area; 58 y/o female).  Irregular brownish discoloration admixed with small whitish specks of ischemic osteosclerosis are scattered throughout this mandible.  Darkest brown area to the right was complete necrosis.  The alveolar crest distal to the tooth was perforated (or never healed properly after the old extractions).

Radiograph from previous mandible shows no obvious radiographic change.  This is characteristic of approximately 1/3 of osteonecrosis cases.

schemic 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.

Radiograph from previous case shows obvious "condensing osteitis" area toward left, with the cavitated area appearing somewhat radiolucent with a superimposed soap bubble or multilocular effect.  The crestal cortex is so thin as to be almost invisible on this radiograph.

Ischemic osteonecrosis with osteosclerosis (mandibular molar to cuspid region, 71 y/o female). Linear discolored, mushy area of necrotic marrow is seen between the inferior alveolar nerve and the inferior cortex.  Mottled white flecks toward the right (anterior) is viable, osteosclerotic bone, presumably from low-level ischemia.
Ischemic osteonecrosis with osteosclerosis (mandibular molar to cuspid region, 71 y/o female). Radiograph of previous case shows minimal change (no change?) of the molar region of osteonecrosis, but osteosclerosis is represented by white radiopacities from superior to inferior borders, toward the right (anterior).

Radiograph from previous mandible shows no obvious radiographic change.  This is characteristic of approximately 1/3 of osteonecrosis cases.

Ischemic osteonecrosis, avascular necrosis (mandibular condyle, 49 y/o female). Darkly discolored superior portion of the condyle is honeycombed with small cystic spaces, often with denuded trabeculae (slight yellow/white color).  The posterior superior region was extremely mushy while the less darkly discolored inferior portion of the photo was relatively firm and microscopically showed only bone marrow edema.