Response of mandibular condyles of juvenile and adult rats to abnormal occlusion and subsequent exemption.

Objective: The adaptation capacities of the mandibular condyle in response to mechanical stimuli might be different between juveniles and adults, but has not been compared. This study aimed to investigate whether abnormal molar occlusion and subsequent molar extraction could lead to different remodeling responses in the mandibular condyles of juvenile and adult rats.

Methods: Abnormal molar occlusion (AMO) was established in the 5- and 16-wk old rats by moving their maxillary left and mandibular right third molars distally.

Activation of α2A-adrenergic signal transduction in chondrocytes promotes degenerative remodelling of temporomandibular joint.

This study tested whether activation of adrenoreceptors in chondrocytes has roles in degenerative remodelling of temporomandibular joint (TMJ) and to determine associated mechanisms. Unilateral anterior crossbite (UAC) was established to induce TMJ degeneration in rats. Saline vehicle, α2- and β-adrenoreceptor antagonists or agonists were injected locally into the TMJ area of UAC rats.

β2-Adrenergic signal transduction plays a detrimental role in subchondral bone loss of temporomandibular joint in osteoarthritis.

The present study tested whether activation of the sympathetic tone by aberrant joint loading elicits abnormal subchondral bone remodeling in temporomandibular joint (TMJ) osteoarthritis. Abnormal dental occlusion was created in experimental rats, which were then intraperitoneally injected by saline, propranolol or isoproterenol. The norepinephrine contents, distribution of sympathetic nerve fibers, expression of β-adrenergic receptors (β-ARs) and remodeling parameters in the condylar subchondral bone were investigated.