She smiled, too, her incisors creeping out from behind her lips.
We have teeth that allow us to grind plants (molars) or tear flesh (incisors).
"cutting tooth," 1670s, from Medieval Latin incisor "a cutting tooth," literally "that which cuts into," from Latin incisus, past participle of incidere (see incision). Inscisours as the name of a cutting tool is attested from early 15c.
incisor in·ci·sor (ĭn-sī'zər)
Any of the four teeth adapted for cutting or gnawing, having a chisel-shaped crown and a single conical root and located in the front part of both jaws in both deciduous and permanent dentitions.