Effect of intraarticular teriparatide application on temporomandibular joints with osteoarthritis: Histomorphometric and immuno histochemical analysis

Temporomandibular joint osteoarthritis as a result of factors based on mechanical and biological etiology; It is a chronic disease that causes destruction in subchondral bone, cartilage, synovium and surrounding tissues. The aim of this study was to evaluate the effect of teriparatide injection on cartilage destruction and joint inflammation in temporomandibular joint osteoarthritis. Complete Freud's Adjuvant (CFA) injection method was used to create an osteoarthritis model. In our study, 40 male Spraque-Dawleys were divided into four groups as one normal group and three study groups. Group 1: Normal group (n=10), Group 2: CFA+ intraarticular serum group (n=10), Group 3: CFA + intra-articular hyaluronic acid group (n=10), Group 4: CFA + intra-articular teriparatide group (n=10). 2.,3. Injections in groups 4 and 4 were started one week after the CFA injection and were repeated three times at intervals of one week. On the 28th day, the animals were sacrificed. The effects of teriparatide on cartilage destruction and synovial inflammation were examined histopathologically. Condylar cartilage thickness, osteochondral junction and articular disc thickness were measured in histomorphometric examination. In immunohistochemical examination, apoptotic chondrocyte count was performed and IL-6 expression was evaluated. Histological examination revealed that teriparatide reversed the signs of inflammation. Condylar cartilage thickness measurement showed a statistically significant increase in the teriparatide group compared to the other groups. Articular disc thickening due to inflammation decreased significantly in the teriparatide group. Chondrocyte apoptosis in the treatment groups was found to be significantly lower than in the arthritis group. Differences between treatment groups were significant in all assessments. IL-6 expression was significantly decreased in the treatment groups compared to the arthritis group. In conclusion; Intra-articular teriparatide treatment showed a curative effect by preventing inflammation and cartilage destruction in temporomandibular joint osteoarthritis.