This study was undertaken to examine the presence of type II and type III collagen in the cartilage of the mandibular condyle in different types of temporomandibular joint (TMJ) pathology, including rheumatoid arthritis (RA), to assess to what degree the newly formed tissue is cartilaginous.
Tissue samples from 46 TMJ surgery patients (37 women and 9 men; mean age, 37 years; range, 14 to 76 years) were investigated. The samples were obtained at surgery mostly from anteriorly situated osteophytes or the anterosuperior uneven articular surface of the condyle. Tissue sections were stained with hematoxylin-eosin, toluidine blue, and Gomori's reticular stain. Type II and type III collagens were demonstrated by immunohistochemical staining.
The amount of type II collagen was variable in the mandibular condylar cartilage. Type III collagen was found in the new osteoid tissue as well as the new chondroid tissue that was synthesized in the most reactive situations.
Type II collagen synthesis occurred mainly in condylar hypertrophy and the intermediate stage of internal derangement of the TMJ. Type III collagen, which is found in fibrous repair tissue, was also found in sites of repair of mandibular condylar cartilage, including RA and osteomyelitis.