Age 1 1/2 Years - Teeth 1,2,3, are milk teeth that have not been replaced and are usually heavily worn. Tooth 3 has three cusps. Teeth 4,5,6 are permanent teeth. Tooth 6 may or may not be fully through the gum.

Age 2 1/2 Years - Teeth 1,2,3, have been replaced with permanent teeth and have very little wear Tooth No. 3 has two cusps instead of three. Tooth No. 4 has very little wear that is dentine (dark area) of tooth No. 4 is not wide as the enamel (white area) that surrounds it. The posterior cusp of tooth No. 6 shows slight wear.

Age 3 1/2 Years -The dentine of tooth No. 4 is as wide or wider than the enamel that surrounds it. This is not true of tooth No. 5, the posterior cusp of tooth No. 6 shows definite wear, and is almost flat.

Age 4 1/2 Years - The dentine of teeth No. 4 and 5 is as wide or wider than the enamel that surrounds it. This is not true of tooth No. 6. The posterior cusp is badly worn and outer edges slope downward.

Age 5 1/2 Years - The dentine on teeth No. 4,5,6, is as wide or wider than the enamel which surrounds it.

Age 6 1/2 Years -Tooth No. 4 is worn smooth. Teeth No. 5, 6, like 5 1/2 year old deer.

Age 7 1/2 Years -Teeth No. 4,5, are worn smooth.

Age 8 1/2 Years or older - Teeth No. 4,5,6, are all worn smooth.