Alterações na articulação temporomandibular de equinos

There is currently no description of the association of malocclusions with pathologies in the temporomandibular joint of horses. Studies have demonstrated an association of age with alterations in imaging examinations and inflammatory biomarkers of the joint. The objective of this study was to study animals of different ages with presence of malocclusions and to determine their association with joint alterations. Eighteen equines were used, totaling 38 analyzed joints. The animals were divided into groups less than five years old (8 animals); between 5 and 10 years (6 animals) and over 10 years (5 animals). The animals were submitted to physical examination of the oral cavity and the temporomandibular joint, evaluation of superficial temperature, ultrasonography, radiography and analysis of synovial fluid. Comparisons were made between the groups and the association between dental malocclusion and age, malocclusion and joint changes, age and synovial fluid characteristics, as well as age and types of radiographic and ultrasonographic changes. Data were described in frequency and means, with frequencies of occurrences of the changes assessed by chi-square test or Fisher's exact test when appropriate. For the fluid characteristics in animals with alterations in the imaging tests, adjusted variance analysis was used for mixed model with comparison of means by means of the T test. The results demonstrated temporomandibular joint image changes in all studied groups, with a higher prevalence of changes in the group of animals older than 10 years, with changes in cytological characteristics of synovial fluid related to age and stage of synovial tissue alteration. There was an association between the presence of a step in the premolar and molar teeth with radiographic changes (p <0.05). The alteration profile in the radiographic and ultrasound examinations of these animals were indicative of osteoarthritis. The findings corroborate the description that age is related to changes in imaging tests.