The surface that is away from the midline of the face.
The surface that faces the cheeks or lips. Can also use the terms:
The biting edge of an anterior tooth.
The surface that faces the tongue.
The surface that is closest to the midline of the face.
The chewing surface of posterior teeth.
Tooth surfaces that are next to each other (i.e., distal of lateral incisor and mesial of canine).