Antinuclear antibody and rheumatoid factor positivity in temporomandibular disorders

To investigate the differences in clinical characteristics and long-term treatment outcomes according to antinuclear antibody(ANA) and rheumatoid factor(RF) positivity and the correlation between pain-related and hematological indices in temporomandibular disorders(TMD) patients.

Clinical examinations were done following the Research Diagnostic Criteria for TMD in 257 patients. Comprehensive screening along with psychological and hematological evaluations (ANA, RF, complete blood cell count, C-reactive protein[CRP] and erythrocyte sedimentation rate[ESR]) were conducted. Clinical characteristics and treatment outcomes were statistically compared between ANA/RF positive and negative groups.

Thirty-nine patients showed ANA/RF positivity. Male patients had smaller comfortable mouth opening(CMO)(p = 0.033) and maximum mouth opening(MMO)(p = 0.016) ranges with more painful neck muscles on palpation when RF/ANA positive. Pain duration, intensity, disability days and psychological distress levels were also higher in RF/ANA positive male patients. Significant correlation was shown in ESR with pain duration(p < 0.05) and numeric rating scale(NRS) before treatment(p < 0.05), CRP with NRS before treatment(p < 0.01), and red blood cell (RBC) with pain intensity(p < 0.05), NRS before treatment(p < 0.01), CMO(p < 0.01), pain on palpation of cervical muscles(p < 0.01), CMO(p < 0.05), and MMO(p < 0.05) 6 months after treatment.

These results may point towards a nonspecific autoimmune disposition in a subgroup of TMD patients. RF and ANA could be considered as a screening test for the detection of autoimmune phenomena in TMD.