I had a chance recently to talk about articulators with a technician who was still a bit confused about the idea of fully adjustable versus Semi- Adjustable. So as a refresher let us go through what makes the difference in the descriptive terms used.
First, remember that we are talking about full frame articulators, those that have an intercondylar distance of 110 millimeters. Any articulator smaller than that may be adjustable, but cannot be considered fully adjustable because it cannot reach the dimensions of the average human skull.
With that said, there are Fixed type articulators. A good example of this would be the DENAR Automark or the Denar Mark 310. These articulators have average anatomical settings, which are fixed in the upper and the lower members. These are a 25 degree protrusive angle, a 7 degree or 15 degree progressive side shift, depending upon the articulator and an intercondylar distance of 110 millimeters. You cannot change these settings. They are based on the average studies of Drs. Bennett and Bonwill.
Then there are Semi-Adjustable articulators. These come in many configurations in the industry but here at Whip Mix they are the Whip Mix Articulators, with the exception of the Mainstay disposables. The Hanau Wideview, Modular and H2 Series and the DENAR MarkII, COMBI II, Anamark and the remainder of the DENAR 300 Series, the 320 and 330. All of these Articulators are in some way adjustable at the Fossa, allowing for Progressive Side Shift, Immediate Side shift and Condylar Inclination. They also have a fixed Condylar distance of 110 millimeters.
The Semi Adjustable’s look fancy enough, but what is the function that holds them back from being fully adjustable?
They all lack the ability to change the intercondylar distance.
Some of you still use the Whip Mix 8500 (Dr. Charles E. Stuart Type) Articular. You will remember that on this articulator you can change the intercondylar distance. Those condyles can be positioned in S, M and L threaded holes that correspond to the S, M and L markings on the associated Face Bow. Does this make the 8500 fully adjustable? No, because the three condylar positions are fixed.
So which of the articulators are actually fully adjustable? It is the DENAR D5A.
This instrument has the capability of adjustment in all of the aforementioned positions. It also uses the Cadiax Facebow system to record the patient's Jaw movements, not just a simple facebow. Can you use the D5A as a fixed or Semi Adjustable Articulator. The answer is yes, by fixing the settings at the averages or by allowing the condylar balls to be set at 110mm and then allowing for the adjustment of the condyles as needed for the patient.