A method for rapidly creating a custom mouthpiece is disclosed. The method may include providing a form defining a void sized and configured to accommodate teeth of a user. The method may also include applying a curing polymer within the void. The method may also include placing the form and the curing polymer within a mouth of the user so as to move the teeth of the user into the curing polymer to make a mold of the teeth of the user. The method may also include allowing the curing polymer to cure while in the mouth of the user, and removing the form and curing polymer from the mouth of the user.