Rheumatoid arthritis (RA) is an inflammatory arthritis that affects synovial joints, and it is not surprising that the temporomandibular joint (TMJ), a synovial joint, is also affected. However, TMJ is rarely the first affected joint in the course of RA. Often, RA patients come to the physician with more focus on complaints in other peripheral joints. Therefore, asking TMJ complaints and symptoms, and TMJ examination in RA patients is often neglected by doctors too, because they focus more on other joints. This neglect may cause serious damage to the joints and cause disability. Examination of TMJs, which is a crucial component of vital activities such as nutrition and speech, should be added to the routine. Also, further studies may be focused on adding TMJ assessment to disease activity scales and health assessment questionnaires.

Bone formation is a complex process that occurs throughout life, and is normally limited to the skeletal system. In bone formation, osteoprogenitor cells follow several developmental stages, including differentiation in osteoblasts, proliferation, matrix maturation, and mineralization. The mechanisms involved in the mineralization process of bone, such as in the new bone formation, are extremely complex and have been under intense investigation for many years. Bone formation follows two distinct processes, intramembranous and endochondral ossification; both are regulated by signaling pathways involving numerous genes. Disturbance of these signaling pathways may cause a large spectrum of skeletal diseases characterized by new bone formation and bone growth anomalies. This review will only focus on the key genetic pathways involved in heterotopic bone formation. Wingless/integrated (Wnt), hedgehog (HH), and transforming growth factor beta (TGFβ)/bone morphogenetic protein (BMP) signaling pathways are described and illustrated; their relation with new bone formation is demonstrated through their involvement in bone formation disorders.

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease of unknown origin. Although it mainly affects joints, it can have extra-articular manifestations, with the lung being one of the most affected organs. The estimated incidence of diffuse interstitial lung disease (ILD) is 4 cases to 4.5 cases/1000 patient-years. The most common forms are usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP; 44–46% and 33–44%, respectively), although there have been reports of cases involving all the histopathologic forms described for the disease. RA-ILD is associated with specific risk factors, such as male sex, older age, smoking, and positive rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA) levels. The clinical course of ILD ranges from asymptomatic forms to rapidly progressive disease in a minority of cases. It has been estimated that the risk of death is up to 3-fold higher in patients with RA-ILD than in those without ILD, making RA-ILD the second most common cause of death after cardiovascular disease. Treatment of RA has improved considerably in recent years with the advent of biologics; however, the use of these agents has been restricted in patients with ILD owing to safety concerns. Many doubts continue to surround the treatment of patients with RA-ILD. Therefore, the objective of this review is to examine the current management of affected patients in terms of diagnosis, treatment, and follow-up.