Variations of the Anterior Set-up
I. Variations of the Anterior Set-up In a Class II Relation Case, Using 0 Degree or 10 Degree Posterior Teeth
- The maxillary anterior teeth are set in exactly the same way as was described previously.
- Go through protrusive and lateral movements on the articulator in order to determine the projected anterior teeth clearance in these protrusive positions.
- Mandibular midline is the same as the maxillary midline.
- The maxillary teeth have been set in their most esthetic position and the mandibular anterior teeth are set so that they appear to emerge from the anterior body of the mandible at the natural angulation. All of the mandibular anterior teeth are set without regard for horizontal overlapping.
- All of the mandibular anterior teeth will be set with a 1 to 3mm vertical overlap relative to the maxillary anteriors, depending on the anterior clearance, which is needed. They will be set on a flat plane from left to right.
- Axial inclinations from the facial are the same as the corresponding maxillary teeth.
- The arch form of the mandibular teeth as viewed from the incisal follows the arch of the mandibular ridge.
- Individual teeth may be rotated or slightly repositioned for esthetic purposes.
II. Variations of the Anterior Set-Up in a Class III Ridge Relationship Case, Using 0 Degree or 10 Degree Posterior Teeth
- The maxillary anterior teeth are set in exactly the same way as described previously.
- The mandibular teeth are set edge-to-edge with the maxillary teeth. This means that the incisal edges of the mandibular anterior teeth are right under and in direct contact with the incisal edges of the maxillary anterior teeth.
- The midline of the mandibular anterior teeth is the same as the maxillary midline.
- There is no vertical or horizontal overlapping
- The facial and axial inclinations of the mandibular anteriors are the same as the maxillary teeth.
- In most Class III cases, the mandibular cuspid will incise with the maxillary lateral incisor. This means that the mandibular first bicuspid will occlude with the maxillary cuspid, and the mandibular second bicuspid with the maxillary first bicuspid, and the mandibular first molar with the maxillary second bicuspid and first molar. The distal portion of the maxillary first molar will occlude with the mesial portion of the mandibular second molar if there is enough room before the ascending ramus begins.
- Altering the shape of some or all of the teeth is frequently necessary in order to achieve an esthetic set-up.
- In some Class III cases, further bucco-lingual tooth placement variation may be necessary in order to achieve a reasonable relationship between the maxillary and mandibular teeth.