Which term refers to the surface of the tooth that is adjacent to the lips?

The term that refers to the surface of the tooth that is adjacent to the lips is "Labial." In dental anatomy, surfaces of the teeth are classified based on their locations and the adjacent anatomical structures. The labial surface specifically pertains to the portion of the incisors and canines that faces the lips. This terminology helps dental professionals accurately describe areas of concern during examinations and procedures.

In contrast, the lingual surface pertains to the side of the tooth that faces the tongue, the palatal surface is used for that which faces the palate of the mouth (primarily for the upper teeth), and the distal surface is the one that is furthest away from the midline of the dental arch. Each of these terms has a specific location, thereby clarifying the relationships and orientations of teeth within the oral cavity.