“The lips are two fleshy folds which surround the orifice of the mouth, formed externally by integument and internally by mucous membrane, between which are found the Orbicularis oris muscle, coronary vessels, nerves, areolar tissue, and fat and numerous small labial glands.”<sup>17 Gray H. Anatomy, Descriptive and Surgical: A Revised American, from the Fifteenth English, Edition New York: Bounty Books (1977).  869-870

Haga clic aquí para ir a la sección de Referencias</sup> This anatomic description of human lips appeared at the beginning of the twentieth century. In the new millennium, it is understood that lips are much more than the sum of their parts.