The use of SPECT bone scans to evaluate patients with idiopathic jaw pain

The purpose of this study was to investigate the potential usefulness of single photon emission computed tomography (SPECT) bone scanning with technetium-99m methylene diphosphonate (Tc-99m MDP) in the diagnosis of idiopathic jaw pain. Unlike planar bone scanning, SPECT uses tomographic technology to provide 3-dimensional images, which are more useful in localizing small lesions.

Twenty patients, each with a diagnosis of chronic idiopathic jaw pain, were compared after SPECT bone scanning with 20 age-matched and gender-matched normal controls. Uptake was identified and compared in sites with previously detected jaw pathoses and jaw pain.

Nineteen of 20 patients with jaw pain evaluated with SPECT had positive scans, in contrast with 12 of 20 control subjects (P <.04). Positive scans were correlated with painful sites in 15 of 20 patients, with the remaining 5 patients demonstrating no uptake in painful locations. Patients with jaw pain demonstrated 37 of 80 mouth quadrants with positive scans, in contrast with 21 of 80 mouth quadrants in the controls (P <.01). Nineteen of 24 painful mouth quadrants had uptake in the pain group. Of the 21 quadrants positive in the controls, 17 were correlated with previously detected jaw pathoses. The sensitivity and specificity for detecting painful sites were 0.79 and 0.68, respectively. The sensitivity and specificity for detecting previously identified pathoses in the jaws of normal controls were 0. 80 and 0.93, respectively.

Patients with idiopathic jaw pain had a significantly greater frequency of positive SPECT bone scans when compared with normal controls. However, the sensitivity and specificity of SPECT bone scans in detecting painful sites were low. These findings suggest that SPECT bone scanning with Tc-99m MDP is not indicated as a routine imaging procedure for the detection of jaw pathoses, but may be considered as a potential research tool in the future study of chronic idiopathic jaw pain.