Temporomandibular joint cytokine profiles in the horse.

The research sought to understand how age and dental issues might affect inflammation and pain in the jaw joints of horses, known as the temporomandibular joint. Contrary to what was expected, findings showed that only age, not dental issues, influenced the concentration of inflammation-causing molecules, called cytokines.

Research Background

• This study was prompted by the hypothesis that dental abnormalities in horses could cause inflammation and pain in the temporomandibular joint (TMJ), which might be diminished by regular dental care.
• The researchers examined the relationships between age, dental health, and levels of cytokines – specifically IL-1, IL-6, IL-8, TNF alpha, and TGF-beta1, -beta2, -beta3 – in the TMJ of horses.

Research Methods and Findings

• The study took into account the age of the horse and the severity of dental malocclusions, grouped into a “dental pathology score”, in order to measure cytokine concentrations.
• Through their analysis, researchers found that TGF-beta3 was not detected in any TMJ samples across the study. IL-1, IL-6, and TNF alpha levels were not influenced by the age of a horse.
• Notably, foals, or young horses, displayed significantly lower concentrations of IL-8 and TGF-beta1, but higher levels of TGF-beta2 in comparison to older horses.
• Age did not impact cytokine concentration in older horses. However, IL-8 showed a tendency to increase with age.
• The dental pathology score of the subjects tended to increase with age in mature animals, but did not have any effect on cytokine concentrations.
• Moreover, the presence or number of periodontal lesions and the eruption of incisors did not influence cytokine concentrations in the TMJ.

Research Implications

• The study concluded that while age has an impact on the levels of proinflammatory cytokines in a horse’s temporomandibular joint, dental pathology seemingly does not.
• This contradicts previous assumptions that dental abnormalities could lead to an increase in inflammation and pain in the TMJ of horses, indicating that more research is needed in this area to fully understand the relationships among age, dental health, and TMJ inflammation in horses.