It is degenerative disease of weight-bearing joints, although TMJ (tempero-mandibular joint) is not a weight bearing joint.

Clinical features :-

• Pain rarely presents
• Causes clicking sounds while opening and closing mouth
• Limitation of movements of jaw
• Sometimes inflammation can be seen

Histopathology :-

• Vertical and horizontal cracks on articular cartilage
• Cartilage becomes less elastic
• Degeneration of chondrocyte
• localised destruction of cartilage

Treatment :-

• NSAIDs are extremely beneficial for treating patients with TMJ Osteoarthritis as they have a dual effect of reducing pain and reducing inflammation. 
• Condylectomy should be considered in severe cases

Reference :-

Images :- Google
Writing :- notes made from mastering bds, Sanjay Kumar Purkait books