(18)F-NaF PET/CT for the evaluation of temporomandibular joint disorder.

AIM: To investigate the usefulness of a quantitative parameter (maximum standardised uptake value [SUVmax]) of (18)F-sodium fluoride (NaF) positron-emission tomography (PET)/computed tomography (CT) for the evaluation of temporomandibular joint (TMJ) disorder (TMD). MATERIALS AND METHODS: Seventy-six TMD patients (male: female=14:62, age=40.3+/-17.1 years, bilateral: unilateral=40:36) with 152 TMJs were enrolled. The (18)F-NaF PET/CT parameter (SUVmax) was compared with the presence of TMJ arthralgia (arthralgic=86, non-arthralgic=66) and clinical subtypes based on the Research Diagnostic Criteria for TMD Axis I (TMD osteoarthritis=49, non-TMD osteoarthritis=67, and asymptomatic TMJ=36). Splint therapy was applied to 48 patients for 6 months without considering (18)F-NaF PET/CT findings. Post-splint therapy (18)F-NaF PET/CT was performed in 32 patients and clinical responses to the therapy were classified into improvement (n=33), no change (n=10), or aggravation (n=7) for 50 TMJs excluding asymptomatic TMJs (n=14). RESULTS: SUVmax was significantly greater in arthralgic TMJs than in non-arthralgic TMJs (6.62+/-3.56 versus 4.32+/-1.53, p<0.0001). SUVmax was also significantly greater in TMD osteoarthritis (6.75+/-3.85) than in non-TMD osteoarthritis (5.21+/-2.70) and asymptomatic TMJs (4.86+/-1.99; p=0.0386). After splint therapy, SUVmax was significantly increased in aggravated TMJs (from 7.80+/-3.72 to 11.00+/-5.74, p=0.0156), whereas no significant change in SUVmax was observed in improved (from 6.16+/-2.68 to 6.09+/-2.60, p=0.4915) and unchanged (from 6.46+/-4.19 to 6.77+/-4.32, p=0.3223) TMJs. CONCLUSIONS: (18)F-NaF PET/CT is a useful imaging tool for TMD evaluation because SUVmax showed a fair diagnostic performance for arthralgic TMJ and TMD osteoarthritis, and a correlation with the therapeutic response.