Figure 1.

(A) Representative illustration of the surgery procedure, showing the nylon suture anchorage in the zygomatic arch while stretching the disc. (B) Horizontal skin access between the lateral canthus of the eye and pre-auricular region. Special care was taken with the facial nerve that could easily be dissected. (C) A capsular incision exposed the articular disc and the superior space of the TMJ, so as to see all of the extensions of the disc attachments. A down-traction of the mandible facilitated this step of the procedures. (D) The anterior portion of the disc was transfixed by a nylon wire, allowing for the forward stretching and the suture was double-fixed in the anterior aspect of the zygomatic arch, in order to ensure no unlace. At this moment, an incision into the lateral attachment of the disc allowed for its traction. White star, articular disc. Hash, facial nerve. Black star, nylon suture. White arrow, the posterior zone of the disc and the retrodiscal ligament. (E) Analysis of the fibrocartilage thickness in the H&E-stained slides: the mid-sagittal sections of the TMJ, showing the fibrocartilage in the condyle from the anterior to the posterior zone. The three-thirds of the fibrocartilage were measured at three points, equally divided in each third from the fibrous layer to the hypertrophic layer. (F-H) The ADD group showed an increment in the thickness of their fibrocartilages, at the experimental times, when compared to the sham-operated control group and the infiltration groups, mainly in the anterior thirds. The thickening of this region showed a disorganization in the fibrocartilage layers, especially of the proliferative and the pre-hypertrophic layers. In the other groups, a time-dependent thinning was observed in the fibrocartilages and the posterior portion was generally thicker than the anterior. The thickness of the fibrocartilage (μm) at 15 (F), 30 (G) and 60 (H) days, as measured at the anterior, middle and posterior regions of the condyle. The columns show the mean and the vertical lines the show SEM of the 8 independent experiments. *P < 0.05; **P < 0.01 when comparing ADD to sham-operated rats. #P < 0.05 when comparing the CFA- to the saline injected animals. Bar = 100 μm.