This a continuation of the discussion in part I of some of the philosophies that can be used to determine correct VDO.
The foregoing reviews of different techniques for determining vertical dimension exposed the flaws in each of them, and yet they have all been used successfully, many of them for decades. This means that vertical dimension is a highly adaptable position – that there is no single correct vertical dimension.
Furthermore, using a particular vertical dimension as the rationale for reconstructing teeth that otherwise do not need treatment is not scientifically justified. If the patient needs extensive reconstruction, several different vertical dimensions could be successful. This ultimately leaves us with the question of which one to choose.
Principle Thoughts for Determining the Most Appropriate Vertical Dimension
Since many vertical dimensions may be successful, it makes the most sense to choose the one that satisfies both the patient's esthetic goals and the clinician's functional goals. In many ways, this is the simplest of all methods for determining vertical dimension.
- Mount the patient's existing casts with the seated condyle.
- Establish the ideal maxillary central incisor incisal edge position on the maxillary cast, either in wax or resin composite. This position is arrived at by evaluating the patient's maxillary central incisor display with the upper lip at rest and in a full smile.
- Determine if any alteration of the lingual contour of the maxillary incisors is necessary, and if so, pre-form that alteration in wax or resin composite as well. Essentially, the desired changes to the maxillary central incisors will now have been transferred to the cast.
- Close the articulator and evaluate the anterior and posterior occlusions. In some patients the desired changes to the maxillary anterior teeth may be made without a significant alteration in the anterior or posterior occlusion. In other patients, however, the changes performed on the maxillary anterior teeth will result in a posterior open bite when the articulator is closed. The decision that must be made is whether to close the posterior open bite by building up the posterior teeth, hence opening the vertical dimension, or by altering the mandibular incisors. In many patients either approach may be successful. Generally, the clinician can be guided by evaluating which teeth need restoration in determining whether the mandibular incisors should be modified or the posterior teeth built up. Whenever possible, using the patient's existing vertical dimension makes it easier for the patient to phase in treatment over time.
- Modify the mandibular incisors, if necessary, shortening them until the posterior teeth occlude (if that is the ultimate decision). In many cases of severe wear, lengthening them to avoid the need for crown lengthening establishes the new vertical dimension to which the posterior teeth will be built.
The vertical dimension that is chosen should combine the esthetics of the maxillary and mandibular incisor incisal edge position, the restorative needs of the anterior and posterior teeth, and the desired functional needs of overbite and overjet. It is arrived at on the articulator through trial and error, balancing all of the previous factors while attempting to do what serves the best interests of the patient. It is the adaptability of patients to alterations in vertical dimension that allows us to take this approach to treatment rather than to believe that only one vertical dimension can be acceptable.