Incisor
An incisor was a type of tooth located in the front of the mouth.

In Humans, incisor teeth were believed to have been fangs at one point. In 2266, Doctor Robert Crater compared Humans' retention of incisors and a chameleon's ability to change color for camouflage to the M-113 creature's ability to change forms, saying it was a survival mechanism. ()

In 2372, shortly after the birth of Naomi Wildman, The Doctor advised her mother, Samantha, that Naomi's incisors would soon appear, which meant that Samantha would need to find alternatives to breast feeding. ()

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Anatomy