Correlation between single photon emission computed tomography and histopathologic findings in condylar hyperplasia of the temporomandibular joint.

PURPOSE: To analyse the correlation between the level of activity measured in the single photon emission computed tomography (SPECT) and the pathological findings in patients with condylar hyperplasia (CH). MATERIALS AND METHODS: All patients evaluated in our department between 2007 and 2014 with a diagnosis of condylar hyperplasia who had undergone SPECT, evidenced signs of activity, and had undergone surgery were included. We included 28 patients, of whom 20 were women and 8 men. RESULTS: The male:female ratio was 2,5:1. The mean age of the subjects was 24.4 years at the time of diagnosis (with a range between 14 and 42 years). In 19 cases the affected condyle was the right, and in the remaining 9 it was the left (ratio R:L 2,1:1). On the SPECT, in 16 patients a high level of activity was identified (57.1%) and in the remaining 12 a low level (42.9%). Only 13 patients (6 in the low-activity group and 7 in the high-activity group) presented with islands of cartilage. When comparing the results between the two groups, the main differences were observed in the parameters related to the islands of cartilage. These were more frequent in the group with high activity compared with low activity (5.5 versus 0 per mm2 of median). Besides being more frequent, these islands were larger (more than double) in the high-activity group (385.1 µm versus 169.7 µm of median). This is the only statistically significant difference found, a fact that can be explained by the small sample size in the study. CONCLUSION: Radioisotope tests are the best indicator of the level of activity in condylar hyperplasia, which seems to be directly related to the intensity signal collection.