Topl: occlusal view on the lower incisors of a 6-yr-old mare. Dental stars are visible on I1 and I2 (arrows); cups are present as large elliptical infoldings (arrowheads). Occlusal surfaces of the incisors are oval, and curvature of the dental arch is semicircular. Bottom: occlusal view on the lower incisors of a 12-yr-old mare. In the center of the dental stars, a white spot is clearly visible (arrows). Cups have become smaller and more shallow. Occlusal surfaces are more triangular.