Alternative Names: Ratner bone cavities, alveolar cavitational osteopathosis, Robert's bone cavity, trigger point bone cavity and interference field.
Neuralgia-inducing Cavitational Osteonecrosis (NICO) has been described in medical literature since 1976. In cases of 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. NICO is not generally accepted as a cause of Trigeminal Neuralgia (TN) by most medical and dental professionals. It is possible that NICO is involved in some cases of facial neuralgia, especially atypical facial pain. One long-term study has reported considerably or totally reduced pain in 74% of facial neuralgia patients who had jawbone curettage. However, the pain returned for about 30% of these patients, of whom most had been diagnosed with either TN or atypical facial pain.
In dental circles there appears to be two distinct schools of thought on NICO. Some medical and dental professionals consider NICO a controversial diagnosis. Not only do they not consider it a possible cause of trigeminal neuralgia or other facial neuralgias, they also doubt the condition exists as a disorder. They point to data suggesting bone cavitations are found routinely in cadaver jawbones, casting doubt on the theory that bone cavities cause facial neuralgias.
Other dentists believe NICO is the culprit in many facial pain syndromes and that these painful conditions can be cured by jawbone curettage (scraping and removing infected tissue). They point to studies that show a high success rate for jawbone curettage. Some of these dentists believe that root canals and mercury fillings are partly responsible for NICO.
The only known treatment for NICO is jawbone curettage, in which the jawbone is opened, the infected area drilled out, and the bone biopsied to confirm the presence of inflammation or infection. Often the bone cavity is packed with antibiotics such as teramyacin. A course of antibiotic treatment may be prescribed. Jawbone curettage is not currently done routinely, and it is too early to say whether or not it will ever become generally accepted.