| The large, ever growing incisors in both rabbits and rodents do not undergo functional replacement. |
| Most diprotodonts have three pairs of incisors in their upper jaws, but this number is reduced to one pair in one family, the wombats. |
| The lower jawbone of the hippopotamus reveals six incisor teeth, whereas the hippopotamus that survives in Africa has only four incisors. |
| Rodents and lagomorphs are prime examples of breeders among mammals and have enormous incisors for their body size. |
| Ruminants also lack incisors in the upper jaw, and most lack canines in the upper jaw as well. |
| We recognize four basic kinds of teeth in an individual's jaw, the incisors, canines, premolars, and molars. |
