Slleipnir, yep that's really good. G.P Girl, yours is too! I think G.P Girl has the right of way to post a question, since she answered first.

Stars and cups are the shapes that appear in horses teeth. At age 10 horses will start to get their Galvayne's groove, which general disappears at age 30. At age 12, some horses get wolf teeth. At age 5 the horse should have oval teeth with a large cup, at age 10 the tooth turns round and gets a star along with an enamel spot. When a horse is 15 the teeth are triangular and can have a small enamel dot. By age 20 their teeth are biangular and have a star. There is also a hook that appears on top inscisor 2 at age seven, is gone by age 9, and reappears at age 11.

I had to learn a lot about teeth and aging for camp, I had to help age 48 horses, that was a lot of work and a lot of confusion.

There is a lot more to it than what you see here, but it would require me to type a post that would take an hour, there is so much to learn.