| Code | Display | Definition |
| M | Mesial | The surface of a tooth that is closest to the midline (middle) of the face. |
| O | Occlusal | The chewing surface of posterior teeth. |
| I | Incisal | The biting edge of anterior teeth. |
| D | Distal | The surface of a tooth that faces away from the midline of the face. |
| B | Buccal | The surface of a posterior tooth facing the cheeks. |
| F | Facial | The surface of a tooth facing the lips. |
| L | Lingual | The surface of a tooth facing the tongue. |