The surface of the teeth in both jaws that touches the lips.

Ligating Modules

A small elastic o-ring, shaped like a donut, used to hold the archwire in the bracket.


A tiny rubber band, or sometimes a very thin wire, that holds the orthodontic wire in the bracket.


The tongue side or inside of the teeth in both jaws.

Lip Bumper

This orthodontic appliance moves the lower molars back and the lower front teeth forward to make room for crowded front teeth. By applying pressure to the bumper, the lower lip muscles move the molars back.

Lip Incompetence

An inability to close the lips at rest, most commonly caused by protruding front teeth or an excessively long face.