Temporomandibular Joint Cytokine Profiles in the Horse

Abstract

It has been suggested that dental abnormalities lead to temporomandibular joint inflammation and pain that may be mitigated by regular dental care. There is considerable literature on the pathophysiology of equine joint disease including studies on cytokine profiles in diseased appendicular joints. This study examined the effects of age and dental malocclusions summarized as a dental pathology score on equine temporomandibular joint cytokine (IL-1, IL-6, IL-8, TNF α and TGF-β1, -β2, -β3) concentrations. TGF-β3 was not detected in any joint sample. IL-1, IL-6 and TNF α were not influenced by age. Foals had significantly lower concentrations of IL-8 and TGF-β1, and higher levels of TGF-β2 compared with older horses. Age did not effect cytokine concentration in older horses although there was a trend towards increasing IL-8 with age. The dental pathology score increased with age in mature horses, however there was no effect of dental pathology score on cytokine concentration. There was no effect of incisor eruption, and presence or number of periodontal lesions on temporomandibular joint cytokine concentration. Our findings indicate that age but not dental pathology affected temporomandibular joint proinflammatory cytokine concentration in this population of horses.