# Temporomandibularibular Disorders and Serological Tests in Patients with Rheumatoid Arthritis
## 4 Discussion  
The percentage of women affected by RA in the study sample was higher than males (about 88% vs. 11%), and this is in agreement with the worldwide female gender prevalence of rheumatoid conditions reported in the recent literature [28; 29; 30]. The relationship between different serological factors and TMJ involvement in adults affected by RA has already been demonstrated in previous publications [6; 28]. Specifically, authors evaluated the association of some serological tests with the prevalence of TMJ disorders assessed by the first research diagnostic criteria (RDC)/TMD axes [28] and with the radiographic TMJ changes. [PERSON] et al. [6] showed that on CBCT evaluations, the ACPA can be a good indicator of changes in condylar measurements, mainly in the case of highly destructive disease of the TMJ. Conversely, RF level was considered a poor predictor of condylar size or osteoarthritis changes in RA patients. Recent research showed that RA patients, mainly females, follow an individual skeletal growth pattern evaluated using bidimensional radiological examinations, which are not affected by inflammatory parameters, even if they show joint anatomical asymmetry [31; 32]. Regarding the serological parameters, [PERSON] et al. stated that there is some evidence that specificity in RA classification can be improved by refining the serological weight scoring, taking into account the nature of the antibody (RF versus ACPA), their levels, and the occurrence of combined RF/ACPA positivity. There is now increasing awareness that efforts should be undertaken to harmonize the interpretation of RF and ACPA test results in order to further improve the classifications and diagnosis of RA [29]. The current research evaluated, for the first time in patients affected by the RA systemic disease, the presence of signs and symptoms of TMDs, assessed through the updated \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Crepitus**} \\ \hline
**Characteristic** & **No, N = 14 1** & **Yes, N = 3 1** & \(p\)**-Value 2** \\ \hline Gender & & & 0.99 \\ Female & 12.0 (85.7\%) & 3.0 (100.0\%) & \\ Male & 2.0 (14.3\%) & 0.0 (0.0\%) & \\ Age & 53.00 (16.7\%) & 42.0 (6.00) & 0.15 \\ Hypertension & 10.0 (71.4\%) & 2.0 (66.7\%) & 0.99 \\ Diabetes & 3.0 (21.4\%) & 1.0 (33.3\%) & 0.99 \\ Hepatic Steatosis & 0.0 (0.0\%) & 1.0 (33.3\%) & 0.18 \\ Hyperuricemia & 1.0 (7.1\%) & 0.0 (0.0\%) & 0.99 \\ Lung Disease & 3.0 (21.4\%) & 0.0 (0.0\%) & 0.99 \\ Atherosclerosis & 2.0 (14.3\%) & 0.0 (0.0\%) & 0.99 \\ ESR & 22.00 (20.50) & 21.00 (22.00) & 0.85 \\ CRP & 0.40 (0.95) & 4.00 (2.70) & 0.23 \\ RF & & & 0.99 \\ Negative & 3.0 (21.4\%) & 0.0 (0.0\%) & \\ Positive & 11.0 (78.6\%) & 3.0 (100.0\%) & \\ ACPA & & & 0.99 \\ Negative & 7.0 (50.0\%) & 1.0 (33.3\%) & \\ Positive & 7.0 (50.0\%) & 2.0 (66.7\%) & \\ ANA & & & 0.05 \\ Negative & 10.0 (71.4\%) & 0.0 (0.0\%) & \\ Positive & 4.0 (28.6\%) & 3.0 (100.0\%) & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Association between possible predictor variables and crepitus. DC/TMD, [24] and the putative correlation with some of the RA diagnostic factors revealed by the following serological tests: ESR, CRP, RF, ACPA, and ANA. The assessment of the DC/TMD in this study was carried out by only one examiner to avoid any performance bias. A statistically significant association was found between a negative ACPA and the presence of pain related to the masticatory muscles. This outcome was similar to the previous research in which 80% of TMDs were described as pain in the orofacial region. Similarly, [PERSON] et al. showed a significant correlation between the clinically evaluated presence of TMDs in RA patients and the CRP (57.69%), ACPA (94.23%), and RF (86.53%) serological levels [28]. Moreover, in our study, RF has been found to be positive in more than 80% of patients with RA. The comorbidities more correlated with RA in our sample were hypertension (70%), and also diabetes (23.5%).