Control of Osteoarthritis in Temporomandibular Joint by Local Injection Using Growth Hormone

Objectives: Osteoarthritis (OA) of temporomandibular joint (TMJ) has defects in cartilage and subchondral bone. Growth Hormone (GH) is well known to have a role of stimulation of growth by triggering active growth of chondrocyte. The objective of this study is to evaluate the intra-articulr injection of GH as a suitable treatment option for the TMJ-OA patients.
Methods: Monosodium iodoacetate(MIA) was selected to induce OA in TMJs of rat and rhGH was injected in the articular space of TMJs. The concentration of GH and IGF-I was measured in the blood and synovial fluids, and OA grading of subchondral bone and cartilage degradation were recorded by microCT and histological examination.
Results: MIA induced OA in TMJ itself can up-regulate IGF-I level not GH. After administration of GH through locally injection, level of GH and IGF-I were increased compared to the control group. Locally injected GH improved osteoarthritic score in both subchondral bone and cartilage of TMJ.
Conclusions: Intra-articular injection of GH can play a role in maintaining cellular layers of cartilage and subchondral bone without affecting systemic bone growth in TMJ-OA.