OsseoNews: What is your protocol for establishing the vertical dimension of occlusion and the vertical dimension of rest in an edentulous patient?
Dr. Jameson: As is customarily done, I first establish the rest position of the mandible. But instead of closing the vertical dimension 2-3mm and then making the occlusal registration, this position is recorded and used as the vertical dimension of occlusion with linear occlusion. To determine the vertical dimension of rest position, I use the artistic concept of facial proportion, i.e., dividing the face into thirds (Figure 1). With the patient standing and instructed to relax and let the mandible “hanging loose and limp” with the lips lightly touching, I make a judgment as to whether the face appears to be within normal proportion. In other words, the chin is not too close to the nose or giving the appearance of being stilted open. A measurement is then made to determine if the distance from below the chin to the bottom of the nose is equal to the distance from the bottom of the nose to the eyebrows (Figure 2). It can be verified by having the patient lick the lips, swallow and then relax and check the measurement. But basically, if the face has normal proportions, the mandible is at rest.
Dr. Jameson is a board certified Prosthodontist who has done considerable work in disseminating information concerning the concept of linear non-interceptive occlusion. He was a consultant in Prosthodontics to the Surgeon General, USAF prior to his retirement from active duty and has been a consultant to the Department of Veterans Affairs.