Histopathological changes in rabbit craniomandibular joint associated with experimentally induced anterior disk displacement (ADD)

Abstract

Several studies have shown that anterior disk displacement (ADD) of human temporomandibular joint (TMJ) can lead to cellular and extracellular alterations in the disk proper, bilaminar zone (BZ), condyle, articular eminence and synovial membrane. Due to lack of an animal model for this disease, it is not known whether the mechanical displacement of the disk could lead to the observed histopathological changes. The purpose of this experiment was to investigate the histopathological changes that occur in the rabbit craniomandibular joint (CMJ) following surgical induction of ADD. The right CMJ was exposed surgically and the discal attachments were severed except for the BZ attachments. Then the disk was displaced anteriorly and sutured to the zygomatic arch. The left joint served as surgical control. The CMJs were removed after 24 h, 1 week, 2 weeks or 6 weeks and stained with H&E or modified Masson stain. The results showed neovascularization, cell clustering and fibrillation of the displaced disk. The BZ showed marked fibrosis. The condyle showed subchondral hemorrhage and fibrosis followed by osteoarthritic changes in the articular cartilage. The articular eminence showed chondrocytic clustering and an increase in the amount of chondroid bone. Synovial membrane exhibited marked hyperplasia. We concluded that surgical induction of ADD in the rabbit CMJ leads to cellular and extracellular alterations in the disk proper, BZ, condyle, articular eminence and synovial membrane similar to those described previously in human ADD. It appears that the mechanical trauma resulting from ADD could lead to a cascade of reparative and degenerative changes of the affected joints similar to those described for osteoarthritis.

Validation of a chemical osteoarthritis model in rabbit temporomandibular joint: a compliment to biomechanical models

“…Male rabbits were chosen in this study to prevent hormonal influence on cartilage and bone metabolisms. This choice was supported by numerous previous studies using male animals 1,3,4 . Injection was performed in the lower compartment only, to obtain a mild progression of the degenerative process and to fit with human clinical development of the pathology that is mostly concerned the condylar cartilage.…”

“…The rabbit is known to be a good model for human TMJ because of anatomical similarities and lateral physiological movements that do not exist in other mammals 20 , and it has been widely used in models of TMJ osteoarthritis 1,3,4,14 . Male rabbits were chosen in this study to prevent hormonal influence on cartilage and bone metabolisms.…”

Age-Dependent Physiological Changes in the Histoarchitecture of the Articular Cartilage of the Rabbit Mandibular Condyle: A Morphological and Morphometric Study

“…Changes in the thickness of the layers are observed during remodeling of the condylar cartilage [Bouvier, 1988;Bibb et al, 1992;Paulsen et al, 1999;Visnapuu et al, 2000;Rabie et al, 2003;Wang and Detamore, 2007;Chen et al, 2009]; thickening of the proliferative layer is a marker of bone growth [Bouvier, 1988;Bibb et al, 1992]. Many experimental works in the literature examining the morphology of mandibular condylar cartilage after alterations induced by the presence of an occlusal interference [Rashed and Sharawy, 1993;Chaves et al, 2002] or secondary to articular disc displacements [Ali et al, 1993;Ali and Sharawy, 1994, 1995, 1996Narinobou et al, 2000;Sharawy et al, 2003] employ rabbits as the experimental model, more specifically the New Zealand type (Oryctolagus cunniculus) as its TMJ most closely resembles the human TMJ functionally [Weijs and Dantuma, 1981;Tallents et al, 1990;Dan'kov, 1993;Herring, 2003]. The TMJ of rabbits reaches the adult form 3.5 weeks after birth, when the first and second permanent molars are completely erupted, occlusion is established, and the articular disc is completely developed [Nagy and Daniel, 1992].…”

Animal Models of Temporomandibular Joint Disorders: Implications for Tissue Engineering Approaches

“…1,45,46,51,71 In addition, the use of histology as the primary assessment in many of these studies provides for a lack of quantitative data to compare differences between disc displacement and control groups.…”