Horses have constant growing teeth. They need to get them filed down by an equine dentist every month or so. The horses in the wild, of course, can't get them filed, but their teeth naturally stay small because of the continuous eating and chewing of things.
Most mammals have teeth that cannot grow back or repair when they are damaged. Mammals that gnaw on things experience a lot of wear and tear on those teeth. Eventually the teeth are so worn down they are useless, and the animal can starve. Rodents evolved to have front teeth that grow constantly. For them, gnawing on things just prevents the tooth from growing too long.
all rodents have continually growing front teeth, because they have no roots
Animals with hooves usually have flat wider teeth for grinding in back of the mouth and roundish front teeth for pulling. Members of the deer family have only bottom front teeth.
The two sharp teeth located next to the front incisor teeth in mammals that are used to grip and tear
all rodents have continually growing front teeth, because they have no roots
Animals with hooves usually have flat wider teeth for grinding in back of the mouth and roundish front teeth for pulling. Members of the deer family have only bottom front teeth.
Rodents and lagomorphs both have continuously growing incisors. Lagomorphs and herbivorous rodents also have continuously growing molars. The tusks of many mammals, such as elephants, wild boars, and walruses, also grow continuously.
Rabbit, mouse, beaver apparently all rodents
For your child's two front teeth to grow back, it will likely take about a month. This depends on how close the teeth are to growing in, though.
Rabbits, hares, mice, hamsters, and other animals with growing front teeth nibble down on rocks and their food to keep their teeth from growing out too long.
Most marsupials have sharp teeth at the very front, whether they are herbivores (like wombats and koalas) or carnivores (like Tasmanian devils and quolls). Some then have grinding molars further back. Kangaroos' teeth are different again. Kangaroos are grazing animals and they need strong teeth for chewing the grass they eat. The teeth of the kangaroo are continuously being worn down by the tough grasses they eat. Instead of continuously growing, once a kangaroo's front teeth are worn down completely, they fall out, and the back teeth move forwards to take the place of the worn front teeth. Kangaroos have four such pairs of chewing teeth.
If a person finds that their chin and two front teeth are hurting badly, they should contact their dentist. This could be caused by teeth that are growing improperly in the mouth.