Comparison of the maximum standardized uptake value and magnetic resonance imaging characteristics between temporomandibular joint osteoarthrosis and osteoarthritis.

Osteoarthritis (OAI) and osteoarthrosis (OAO) are subsets of degenerative joint diseases affecting the temporomandibular joint (TMJ), distinguished by the presence of joint pain. However, clinical diagnosis based on pain alone is challenging. This study aimed to differentiate OAI from OAO using imaging modalities, including single-photon emission computed tomography (SPECT-CT) and magnetic resonance imaging (MRI). Data from 65 patients (98 joints) who underwent MRI and SPECT-CT between January 2017 and December 2022 at Gangnam Severance Hospital were retrospectively analyzed. Patients were divided into the OAI and OAO groups based on the presence of TMJ pain and bony changes on MRI. Univariate and multivariate binary logistic regression analyses were performed to identify significant risk factors for two diseases. The maximum standardized uptake value (SUVmax) on SPECT-CT and disc shape on MRI were significantly different between the groups. Combining these two variables provided the highest diagnostic accuracy (area under the curve [AUC] = 0.889) compared with SUVmax or disc shape alone (AUC = 0.846 and AUC = 0.752, respectively). There was significant difference in AUC between disc shape and SUVmax + disc shape (p = 0.023). These findings suggest that the combination of SPECT-CT and MRI findings improves the differentiation between OAI and OAO.