Figure 4.

Structural analysis of temporomandibular joint (TMJ) tissues. (A) Histology images of TMJ disc and condylar cartilage stained with hematoxylin and eosin, Picrosirius red, and Safranin O, respectively. The TMJ disc has a relatively homogenous structure across its depth with little proteoglycans. A thick fibrous mat of collagen fibers exists in the top zone of condylar cartilage, covering the proliferative zone in the middle-deep layer. The images were obtained from the central region of the tissues, parallel to the anterior-posterior direction. (B) Scanning white light interferometry images of the central region of disc and condylar cartilage produced with a scan length of 50 µm. Data restore was used to interpolate over regions of missing data smaller than 35 pixels, with the entire image comprising 640 × 480 pixels, representing an area of 1 mm². Anterior-posterior alignment of collagen fibers is visible in the disc. In each tissue, the anterior-posterior direction runs vertically.