NICO
NEURALGIA-INDUCING CAVITATIONAL OSTEONECROSIS

NICO, it is claimed that small areas of bone in the upper or lower jaw become infected or inflamed and die, producing neuralgia-like pain. Most often, no sign of inflammation appears on x-ray. NICO is said to appear after tooth extraction, jaw surgery, endodontic therapy or crown preparation and is speculated to be the result of a long-standing low-grade infection.

http://facial-neuralgia.org/conditions/nico.html

References

[1] Bouquot JE; Roberts AM; Person P; Christian J. Neuralgia-inducing cavitational osteonecrosis (NICO). Osteomyelitis in 224 jawbone samples from patients with facial neuralgia. Oral Surgery, Oral Medicine, Oral Pathology, 1992 Mar, 73(3):307-19; discussion 319-20.

[2] Bouquot-JE; Christian-J. Long-term effects of jawbone curettage on the pain of facial neuralgia. J-Oral-Maxillofac-Surg. 1995 Apr; 53(4): 387-97; discussion 397-9.