CHAPTER 73 Periodontal Disease
Good dental care in the horse includes recognition and treatment of periodontal disease. Although systematic examination and characterization of tissues enables the practitioner to identify the severity of disease, appropriate choice of treatment requires an understanding of the pathogenesis of the disease process. Identification of the stage of the disease process is necessary for the practitioner to provide effective treatment, form a prognosis, and monitor response to treatment.
ANATOMY
Radiographic anatomy of the teeth and supporting structures is similar to that in humans and small animals. Normal structures include the alveolar bone, lamina dura, alveolar crest, and periodontal ligament space. In horses with periodontal disease, changes can be seen in all these structures. Intraoral radiographs provide images of normal and abnormal conditions.
PATHOGENESIS
In older horses, these widened spaces can rarely be reduced to normal because the mechanisms that maintain the tight battery of teeth diminish with age. Three processes contribute to enlarged interproximal spaces of aging horses (Figure 73-5): the elastic transseptal fibers of the periodontal ligament, which are compromised as the interdental gingiva suffer damage and fail to keep the teeth in close proximity; overlong teeth block normal mesial drift and prevent maintenance of the close-packed positions of teeth in the masticatory battery; and reduced crown length means teeth have limited ability to erupt. This is especially true of the teeth located distally in the arcade, where the angle of eruption is directed mesially. If the length of these teeth is reduced, they cannot erupt and exert the pushing effect that keeps the rest of the arcade together.