With humans our teeth are designed and aligned pretty orderly so we can’t do this…but when I look at something like an Angler fish..I wonder how it isn’t constantly sinking those sharp ass teeth into itself every time it takes a bite.
In: Other
The body (be it of human or non-human animals) grows in an organized, preordained manner. Not only are teeth made to grow in an interlocking way, the jaw of those fish is made not to move in a way that would get those teeth in their gums.
But there are other arrangements, like in alligators, who actually have small sockets in the upper jaw to fit the lower jaw teeth (which is why only the upper teeth are visible when they closed their mouths), and sperm whales who have the same arrangement.
Besides them, you have extinct animals like the saber-toothed cat (*Smilodon*) and the saber-toothed marsupial (*Thylacosmilus*), the latter which even had an elongated chin with skin pouches to protect the long teeth.
Latest Answers