Juvenile porcine temporomandibular joint: Three different cartilaginous structures?. (December 2016)

• Record Type: Journal Article
• Authors: Tabeian, Hessam; Bakker, Astrid D.; de Vries, Teun J.; Zandieh-Doulabi, Behrouz; Lobbezoo, Frank; Everts, Vincent
• Is Part Of: Archives of oral biology. Volume 72(2016)
• Page Start: 211
• Page End: 218
• Publication Date: 2016-12
• Subjects: Mandibular condyle -- Articular disc -- Mandibular fossa -- Juvenile idiopathic arthritis -- In vitro; Mouth -- Periodicals; Mouth -- Diseases -- Periodicals; Dentistry -- Periodicals; Electronic journals; 617.6005
• DOI: 10.1016/j.archoralbio.2016.08.033
• Languages: English
• ISSNs: 0003-9969

Abstract

Highlights: The matrix composition of the three cartilaginous structures that constitute the TMJ was different, both at the tissue and cellular level. Collagen type II and proteoglycan content of the condyle matrix differentiated this type of matrix with that of the disc and fossa cartilage. The cultured cells from the fossa, disc, and condyle cartilage displayed a similar phenotype as the cells embedded in their native tissue. Abstract: Objective: The temporomandibular joint (TMJ) consists of three cartilaginous structures: the fossa, disc, and condyle. In juvenile idiopathic arthritis (JIA), inflammation of the TMJ leads to destruction of the condyle, but not of the fossa or the disc. Such a different effect of inflammation might be related to differences in matrix composition of the cartilaginous structures. Methods: The matrix composition of the three TMJ structures was analyzed in juvenile porcine samples and in an in vitro system of cells isolated from each anatomical structure embedded in 3% agarose gels. Results: The matrix of all three anatomical structures of the TMJ contained collagen type I and its gene expression was maintained after isolation. The condyle and the fossa stained positive for collagen type II and proteoglycans, but the condyle contained considerably more collagen type II and proteoglycans than the fossa. The disc contained neither collagen type II protein nor expression of its gene, and the disc did not stain positive for proteoglycans. Aggrecan gene expression was lower in the disc compared to condyle and fossa cell-isolates. In general, the cell-isolates in vitro closely mimicked the characteristic features found in the tissue. Conclusion: The collagen type II content of the condyle clearly distinguished this cartilaginous structure from the disc and fossa. Since autoimmunity against collagen type II is associated with JIA, the relatively abundant presence of this type of collagen in the condyle might provide an explanation why primarily this cartilaginous structure of the TMJ is affected in JIA patients.