Related Experiment Videos
Histopathological study of human TMJ perforated discs with emphasis on synovial membrane response
E S Helmy1, R A Bays, M M Sharawy
1Department of Oral and Maxillofacial Surgery, Emory University, Atlanta, Georgia.
Abstract:
Fifteen perforated TMJ discs from human cadavers were studied histologically to examine the synovial membranes and to compare the findings with previous experimental results in monkeys. There were four with perforations in the bilaminar zone (these four discs were displaced anteriorly), three in the medial third of the disc, and eight in the lateral third of the disc. Histopathologically, there was an increase in vascularity and strong methyl pyronine-positive cellularity around the margins of the perforations. A young, loose, collagenous tissue lined the lateral margins of the perforated discs. Increased fibrous tissue content of the synovial subintimal territorial matrix and osteochondroid metaplasia were also seen. Severe synovial hyperplasia was visible in all joint recesses, but was greatest within those associated with displaced discs. There was patchy distribution of acidic glycoproteins, especially in the lateral parts of the perforated discs. As in the animal studies, human TMJ disc perforation was associated with a vigorous synovial reaction that was seen to form lateral bridges along the margins.
Insights
Human temporomandibular joint (TMJ) disc perforations trigger a significant synovial reaction, characterized by increased vascularity and cellularity. This response, observed in cadaveric studies, mirrors findings in animal models, highlighting a consistent biological reaction to TMJ disc damage.
Area of Science:
- Temporomandibular Joint (TMJ) Disorders
- Histopathology
- Synovial Membrane Biology
Background:
- Perforations of the temporomandibular joint (TMJ) disc can lead to pain and dysfunction.
- Understanding the synovial membrane's response to disc perforation is crucial for developing effective treatments.
Purpose of the Study:
- To histologically examine synovial membranes in human TMJ discs with perforations.
- To compare these findings with previous experimental results in monkeys.
Main Methods:
- Histological examination of 15 human cadaver TMJ discs with documented perforations.
- Analysis of synovial membrane changes around perforation margins and in joint recesses.
Main Results:
- Perforations were located in the bilaminar zone, medial, or lateral thirds of the disc.
- Increased vascularity and cellularity (methyl pyronine-positive) were observed around perforation margins.
- Young, loose collagenous tissue, increased fibrous tissue, and osteochondroid metaplasia were present.
- Severe synovial hyperplasia, particularly with displaced discs, and patchy acidic glycoprotein distribution were noted.
- Synovial reaction formed lateral bridges along perforation margins, consistent with animal studies.
Conclusions:
- Human TMJ disc perforation elicits a vigorous synovial reaction.
- This reaction includes tissue remodeling and hyperplasia, similar to responses observed in animal models.
- The findings emphasize the dynamic biological response of the TMJ synovium to disc injury.