A cavitation is a hole in the bone, often where a tooth has been removed and the bone has not filled in properly. In the last several years, the term cavitation has been used to describe various bone lesions which appear both as empty holes in the jawbones and holes filled with dead bone and bone marrow. Dead, cavitational areas, which produce pain, are now called NICO (Neuralgia Inducing Osteonecrosis) lesions. Cavitations are often a result of either ischaemic osteonecrosis, due to poor blood flow in the marrow, or a traumatic bone cyst.
In his book an oral pathology, Dr. G. V. Black, one of the early experts on cavitations, suggested surgical removal of these dead bone areas. Other less traumatic measures are now first used and surgery with curetting is used primarily where the patient has significant health effects not resolved by other means. When a tooth is being extracted, in what has been normal dental procedure, the surrounding periodontal membrane is usually left behind.
Theoretically, when a tooth has been pulled, the body will eventually fill in the space in the bone where the tooth once was. But when the membrane is left behind, an incomplete healing commonly taks place which leaves a hole or a spongy place inside the jaw bone. Experts speculate that perhaps this is because the bone cells on either side sense the presence of the periodontal membrane and “think” that the tooth is still there. This appears to be one common cause of cavitations.
Ododontic cysts are also commonly occurring usually in the gums at the tip of a tooth, that have pockets of bacterial infection that can cause inflammation and pain in some cases similar to cavitations. Bacterial infections are also known to have systemic effects.
A cavitation can form in any bone in the body, not just in the jaw bones. There are also other reasons that cavitations form, some of which are localized traumas, poor circulation to the area, clotting disorders, and the use of steroids.
On X-ray of an extracted tooth site, this membrane can form an image that appears to be a shadow of a tooth. Almost always, this is indicative of a cavitation. Most dentists are aware of this phantom tooth image, but they do not recognize it as a site of potential problems. Other means of locating or identifying cavitational areas include sonic imaging (CAVITAT), local anaesthesia, Spect Scan, pressure to determine trigger points, Computer Electro Dermal System, etc. While positive Spect Scans were found in 19 of 20 patients with jaw pain, several control patients with no pain also had positive scans- often finding previous jaw pathoses. Thus the Spect Scan was not sensitive at differentiating painful from non-painful conditions. Some of the other methods had more success at such differentiation.