Of the oral diseases that affect horses, dental occurrences are the most relevant in veterinary practice. The objective of this work was to carry out assessments of the oral cavity of traction horses and military personnel, with emphasis on the analysis of the leveling of the incisor teeth, in order to characterize the main periodontal diseases caused by their alteration. The procedures were carried out in the city of Imperatriz - MA, where 41 horses were evaluated, 30 for traction and 11 for military use. It was observed that the causes of misalignment in both groups were diagonal and ladder bite, ventral and dorsal curvature, diastema, oligodontia, wear due to aerophagia, brachygnathism and prognathism. In both groups, the presence of periodontal disease secondary to malocclusion or diastema was identified. It is observed that the evaluation of the oral cavity of horses is extremely important, because these animals have continuous eruption of teeth, they usually present occlusion changes, which can lead to more serious conditions, causing damage to their health.