PATIENT VISIT 3– Plane of Occlusion
Clinical Procedures

Procedure

1. Place the maxillary record base in the patient's mouth. Observe the patient's upper lip. Approximately 1-2 mm of wax should be visible in the average patient. Some patients may not show any wax at rest because they have long upper lip.

2. Mark the occlusion rim approximately 1-2 mm below the lip line. This represents the approximate length of the incisal edges of the central incisors.

3. Now have the patient say words containing "F" and "V" sounds such as 55, 44, vivacious Vivian. The incisal edges of the maxillary central incisors should contact the inner surface of the vermillion border of the lower lip. This is also called the "wet-dry line" of the lip. If the maxillary rim does not contact the lower lip in this area, the length of the anterior portion of the rim must be adjusted by adding or removing wax. This technique is also used to evaluate the proper anterior-posterior position of the maxillary incisors. Evaluate lip support and adjust if necessary.

4. Determine the relationship of the planes of the wax rim to the inter-pupilary and ala-tragus planes using the Fox Occlusal Plane Indicator and a tongue blade or 2 tongue blade. Remove the maxillary record base and occlusion rim from the patient's mouth.

5. Adjust the occlusion rim to be parallel to the inter-pupilary and ala-tragus planes by adding or subtracting wax for the occlusion rim. A heated rubber base spatula or pancake turner works well for this. Drip excess wax on a folded paper towel and discard to keep your work area neat.

Occlusion rim parallel to the inter-pupilary plane

Occlusion rim parallel to the ala-tragus plane

6. Reinsert the base into the patient's mouth and recheck the occlusal plane with the landmarks. Repeat the procedure until a satisfactory plane of occlusal is established.

7. Scribe the midline on the maxillary rim at this time to represent the location of the central incisors. A periodontal probe works well for this. The patient can assist by holding the bottom of a piece of dental floss while you hold the top in the center of the forehead. Next, scribe the high lip line perpendicular to the midline as the patient smiles his or her widest. Scribe the right and left canine lines at the corners of the mouth when at rest. Dental floss can aid you in marking the canine lines. After contouring the maxillary occlusion rim and establishing the plane of occlusion, your next clinical procedure is the face-bow transfer record. This will allow you to mount the maxillary master cast on the articulator.