Abstract
The aim of this study was to three-dimensionally observe the distribution and the arrangement of fiber system in fibrous walls around the temporomandibular joint and to examine structural differences between the medial and the lateral fibrous capsules and the dynamic characteristics. The tissues without destructive changes were obtained from human cadavers aged 60 years to 90 years.
The elastic fiber staining and KOH-collagenase treatment were performed to observe the arrangement and the distribution of elastic fibers. The three-dimensional arrangement of collagen fibrils was revealed by KOH-Triton-trypsin treatment.
Although elastic fibers in the capsules arranged almost parallel to collagen fibril bundles, they were thick and irregularly branched off in the boundary between the articular disc and capsules.The capsules consisted of many blood vessels and fatty tissues, collagen fiber bundles, and a lump of elastic fibers around the junction of the articular disc. These structuers seem to provide some elasticity to resist the tensile stress. A fibril bundle was more densely packed in the lateral than in the medial of the fibrous capsule. As leaving it from the disc, the fibril bundles appeared to be dense, and became anteroposteriorly or mediolaterally oriented. Minutely the fibril bundles took the form of a simple linear, meandering or spiral appearance and a stack of lamella, as in the disc and retrodiscal tissue. The existence of meandering or spiral fibril bundles and interfibriller elastic fibers may be involved with flexibility of the capsules when the disc anteroposteriorly slides.
