1 Answer

Elephants' teeth are very different from those of most other mammals. Over their lives they usually have 28 teeth. These are:

The two upper second incisors: these are the tusks.The milk precursors of the tusks.12 premolars, 3 in each side of each jaw.12 molars, 3 in each side of each jaw.

Unlike most mammals, which grow baby teeth and then replace them with a permanent set of adult teeth, elephants have cycles of tooth rotation throughout their entire life. The tusks have milk precursors, which fall out quickly and the adult tusks are in place by one year of age, but the molars are replaced five times in an average elephant's lifetime.[39] The teeth do not emerge from the jaws vertically like with human teeth. Instead, they move horizontally, like a conveyor belt. New teeth grow in at the back of the mouth, pushing older teeth toward the front, where they wear down with use and the remains fall out. When an elephant becomes very old, the last set of teeth is worn to stumps, and it must rely on softer foods to chew. Very elderly elephants often spend their last years exclusively in marshy areas where they can feed on soft wet grasses. Eventually, when the last teeth fall out, the elephant will be unable to eat and will die of starvation. Were it not for tooth wear out, their metabolism would allow them to live much longer. However, as more habitat is destroyed, the elephants' living space becomes smaller and smaller; the elderly no longer have the opportunity to roam in search of more appropriate food and will, consequently, die of starvation at an earlier age.
Tusks in the lower jaw are also second incisors. These grew out large in Deinotherium and some mastodons, but in modern elephants they disappear early without erupting.