What is the current understanding of pathogenesis and treatment of TMJ osteoarthritis?
This summary is based on the article published in the Journal of Dental Research: Current Understanding of Pathogenesis and Treatment of TMJ Osteoarthritis (May 2015)
X.D. Wang, J.N. Zhang, Y.H. Gan, and Y.H. Zhou
- Osteoarthritis is a common disease that can cause severe pain and dysfunction in any joint, including the temporomandibular joint (TMJ).
- TMJ osteoarthritis (TMJOA) is an important subtype in the classification of temporomandibular disorders. TMJOA pathology is characterized by progressive cartilage degradation, subchondral bone remodeling, and chronic inflammation in the synovial tissue. However, the exact pathogenesis and process of TMJOA remain to be understood.
- An increasing number of studies have recently focused on inflammation and remodeling of subchondral bone during the early stage of TMJOA, which may elucidate the possible mechanism of initiation and progression of TMJOA.
- The treatment strategy for TMJOA aims at relieving pain, preventing the progression of cartilage and subchondral bone destruction, and restoring joint function.
- Conservative therapy with nonsteroidal anti-inflammatory drugs, splint, and physical therapy, such as low-energy laser and arthrocentesis, are the most common treatments for TMJOA.
- These therapies are effective in most cases in relieving the signs and symptoms, but their long-term therapeutic effect on the pathologic articular structure is unsatisfactory.
- A treatment that can reverse the damage of TMJOA remains unavailable to date.
- Treatments that prevent the progression of cartilage degradation and subchondral bone damage should be explored, and regeneration for the TMJ may provide the ideal long-term solution.
Purpose of the Review
This review summarizes the current understanding of mechanisms underlying the pathogenesis and treatment of TMJOA.
- Pro-inflammatory cytokines, including IL-1β and TNF-α, mediate the imbalance in the metabolism of articular chondrocytes during the progression of TMJOA.
- Chronic inflammation may deteriorate the adaptive capability of the TMJ.
- Numerous studies have indicated that subchondral bone plays an important role in TMJOA pathology.
- The relationships among inflammation, cartilage erosion, and subchondral bone destruction remain unclear. Mechanical sensing of the articular cartilage and subchondral bone may contribute to the understanding of TMJOA pathogenesis, but associated molecular mechanism and signal pathways are lacking.
- RCTs, including participants with a clear diagnosis of TMJOA, should be encouraged to provide high-level evidence for the effectiveness of interventions for the management of TMJOA.
- Most patients with TMJOA who have pain are treated effectively with NSAIDs or arthrocentesis. Diseasemodifying OA drugs that prevent the progression of cartilage degradation and subchondral bone damage should be further explored.
- Most anticytokine therapies are still in the animal study stage, and clinical trials are necessary.
- Efforts directed toward engineering tissues for repair or replacement of the TMJ will facilitate the development of next-generation treatments and may provide the ideal long-term solution. The regeneration of TMJ cartilage and subchondral bone tissue with suitable mechanical and structural properties represents an attractive new area of research.