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Vertical Dimension of Occlusion and Rest

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.

October 10, 2004 in Restoration of Dental Implants, Techniques and Procedures | Permalink | Comments (7)

Centric Relation Record

OsseoNews: What is your procedure of choice in making a centric relation record?

Dr. Jameson: In my hands, an intra-oral needlepoint tracing made with stable recording bases at the central bearing area of the mandibular arch is by far the most accurate. While standing, the patient is instructed to move the mandible forward and backward to achieve the most retruded position. To give the patient a point of reference as to when this is accomplished, the patient is instructed to place the little finger in the ear canal on either side, fingernail to the rear. The patient can then feel the head of the condyle bump the fingers when the mandible is retruded forcefully (Figure 3, 4). From this position, the patient is then instructed to move the mandible from side to side drawing the classic arrow point tracing (Figure 5). It is important this procedure be accomplished without any physical contact between the patient and clinician. The recording bases are then luted together at this point with quick set impression plaster (Bosworth Plastogum). 

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.

October 10, 2004 in Restoration of Dental Implants, Techniques and Procedures | Permalink | Comments (7)