SURFACES, LINE ANGLES, POINT ANGLES, AND THIRDS

Facial Surface

A tooth surface facing the lips or cheeks.

Labial Surface

The facial surface of anterior teeth directed toward the lip.

Buccal Surface

The facial surface of posterior teeth directed toward the cheek.

Lingual Surface

The surface facing the tongue; in maxillary teeth it may also be called the palatal surface.

Palatal Surface

The lingual surface of maxillary teeth facing the palate.

Proximal Surfaces

The mesial and distal surfaces of teeth.

Mesial Surface

The surface directed toward the midline.

Distal Surface

The surface directed away from the midline.

Incisal Edge

The surface/edge of incisors and canines that contacts the opposing teeth during closure.

Occlusal Surface

The surface of premolars and molars that contacts opposing teeth during closure.

Line Angle

The junction where two tooth surfaces meet.

Point Angle

The junction where three tooth surfaces meet.

Anterior Line Angles

Mesio-labial, disto-labial, mesio-lingual, disto-lingual, labio-incisal, and linguo-incisal.

Posterior Line Angles

Mesio-buccal, disto-buccal, mesio-lingual, disto-lingual, mesio-occlusal, disto-occlusal, bucco-occlusal, and linguo-occlusal.

Anterior Point Angles

Mesio-labio-incisal, disto-labio-incisal, mesio-linguo-incisal, and disto-linguo-incisal.

Posterior Point Angles

Mesio-bucco-occlusal, disto-bucco-occlusal, mesio-linguo-occlusal, and disto-linguo-occlusal.

Occluso-Gingival Thirds

Cervical third, middle third, and incisal/occlusal third.

Mesiodistal Crown Thirds

Mesial third, middle third, and distal third.

Faciolingual Crown Thirds

Labial third, middle third, and lingual third.

Root Thirds

Cervical third, middle third, and apical third.