Let's think about this a little bit. Our personal opinions are going to be based upon our own personal biases. Our biases are often dependent upon the clinical experiences that we have had. Indeed in this subject we have a few different categories of assessment of the occlusal vertical dimension. We often times assess this dimension on the basis of the vertical dimension of rest. The vertical dimension of rest is established through different techniques: radiographic, tactile, phonetics, aesthetics, etc. the vertical dimension of occlusion is usually some measurement closed relative to the vertical dimension of rest. It varies on the basis of skeletal jaw relationship with the largest differential being associated with a class II skeletal relationship in the smallest differential ring associated with a class III jaw relationship.

The reality is that we will never really be able to test this through a randomized controlled clinical trial. The reason for this is that an RCT is going to be influenced by the skills of the clinicians running the RCT. So if you have a clinician who is very good at the radiographic assessment of the analysis of the vertical dimension of Rest that individual may not be very good at assessing the tactile method of determining the vertical dimension of rest. Consequently the person who is experienced and skilled in the radiographic technique who then develops and RCT testing it against the tactile technique will undoubtedly find that the radiographic technique is superior. All the while another clinician trying to replicate the same results was experienced in the tactile technique would find opposite results. Remember that the RCT is an exquisite method of eliminating bias or reducing bias. The problem is that bias is not the only factor that relates to research evidence. We have issues of consistency, directness and precision. You might want to look at: http://effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?productid=328&pageaction=displayproduct

So when you ask the question about our opinions on the best method to establish the clues of vertical dimension what you will receive is an answer based upon "our opinions" and those opinions are going to be very dramatically influenced by our experiences, our mentors, etc.

Ultimately I think that you need to, in my opinion, address this situation from a couple of different aspects. When I look at the occlusal vertical dimension I invariably use the tactile method and combine it with the phonetic method and combine it with aesthetics. After the cast are mounted I look at the parallelism of the ridges. I don't do electromyography and it is rare that I do radiographic assessment although I do this from time to time. So all this is important for me. It might not be of any relevance to you. The reality is that these are techniques and techniques are skill-based and experience-based, they will differ from clinician to clinician.

Check out OCT - optical coherence tomography.

This technique should work well in principle and has been tested for this application, but dedicated commercial systems may not be available at this time.

Nothing to add to Dr. Eckert's answer. As complete as it coud possibly be.

Occlusal concepts are still just concepts derived from complete denture practice. To add a little, 99.99% of all clinicians make their first steps having their patients seated comfortably in the dental chair to find the vertical dimension. Also, muscle relaxation is important because most patients lost their oral motor skills (stereognosis) over the years and you will have to manipulate the mandible in centric relation, which takes time.

I agree with Dr. Eckert's comments. I depend primarily on esthetics and phonetics. However, clinical judgment is important to interpret observations and modify accordingly. I find the closest speaking space helpful, and try to run a conversation with the patient. This works best if the patient is comfortable and is unaware that his phonetics are being assessed. Keep in mind that the posterior speaking space varies based on the skeletal jaw relationships. Dr. Pound has a nice paper ( Let /S/ be your guide) that might be helpful in this aspect. Even speaking space can be re-established at a different VD (patients adapt) so there is no single conclusive technique. Your best bet is to use a combination of techniques. Again, clinical judgement is paramount.

Dr Eckart synopsis is mirroring the current clinical situation, logic and extremly well presented.

I totally agree with Dr. Eckert. Definitely there is no single method and we consider that two or three methods we should use. In Chile we use three main parameters, Aesthetic, Functional by swallowing and by phonation.

- Aesthetic: In these cases we determine a vertical dimension allowing proper lip closure without drop lip corners and congruence of three facial thirds.

- Functional: We determined the Vertical Dimension in rest position (by deglusión and / or phonation) and then determined - according to the physiological inoclusión space for each skeletal class - the Occlusal Vertical Dimension (which should be 1-5 mm smaller than Vertical Dimension at Rest).

I hope someone else reply this... agree?

I agree with dr eckert and will add, restorative requirements of the material we are going to be using also plays a role in how much we open the bite. just because a patient has wear and appears to have lost vertical dimension does not mean they have. the only way is to compare ceph's from previous yrs to a current one. obviously we all agree phonetics, and esthetics are key.

To put things in a different perspective: in the nijmegen tooth wear project we are treating patients with severe tooth wear restoratively.

Depending on the space we need for sufficient restoration thickness we increase VD up to 5 mm, we measure at the same time freeway space before an after restorative treatment and we find that FS adjusts itself after a certain time. So mainly we let the required space determine the increase in VD. In case of shortened front teeth, we make a mock up for evaluation of esthetics.

Of course, this is for patients with natural dentitions, and wihout TMD problems.

What we know is that in case of a full denture, the VD is most critical.....

Agree with all the opinion given. On top of phonetic, aesthetic, biometric guide, I also use old denture as a guide for denture patients.

From my personal point of view an important consideration is to make any dimensional changes in a reversable manner to enable confirmation of patient adaptability. Following this the prescribed occlusal scheme can then be copied onto more definitive restorations.