J Korean Acad Prosthodont.  1999 Aug;37(4):516-530.

A FLUOROSCOPIC STUDY ON THE STABILITY OF SKIN REFERENCE POINTS DURING JAW OPENING AND CLOSING MOVEMENT

• Ahn HJ
• Kim CW
• Kim YS
• Kim YH

Abstract

The current clinical technique for occlusal vertical dimension recording is based on marking the skin reference points on the patient's face and measuring between these pints using caliper-like device. And it is difficult to achieve reliable measurements by this technique because of movable soft tissue. The purpose of this study is to reveal the stability of skin reference points by comparing the relative movement between extra-oral skin reference points and intra-oral reference points using X-ray fluoroscope. 10 test subjects were divided into 2 groups : Group I (natural dentition) and Group II (denture-wearer whose vertical dimension was lost) and Group III consists of identical test subjects to Group II with their upper denture removed and record base inserted. Attaching the 3mm diameter steel ball to nose tip, chin and to existing denture (or record base), fluoroscopic examination and recording were taken during 2 jaw opening and closing movements. After subsequent digitization using personal compute, 1219 still pictures with 0.1 second interval were made. Using the 2 dimensional graphic software, measurements between reference points were executed. Dividing the entire jaw movement into 3 ranges (total, 1st half opening, 2nd half opening), rate of movement and relative movement between extra-oral and intra-oral reference points were calculated and statistically analyzed. The results of this study are as follows. 1. Within the same experimental group, no statistical difference was found in the stability of skin reference between lower lip point and chin point during total range of jaw opening and closing movement (p>.05). 2. In the first half range of jaw opening, statistical difference was found between Group I (natural dentition) and Group II (denture wearer) (p<.05). Group I has greater skin reference stability than Group II. 3. In the first half range of jaw opening, statistical difference was found between Group I and Group III (record base wearer) (p<.05). Group I has greater skin reference stability than Group III. 4. In the first half range of jaw opening, no statistical difference was found in the stability of skin reference between Group II and Group III (p>.05). 5. In the second half range of jaw opening, no statistical difference was found in the stability of skin reference between any experimental groups (p>.05). 6. In patients with their occlusal vertical dimension lost, employing other measuring references rather than skin is recommended because of low stability.

MeSH Terms

Chin
Dentures
Humans
Jaw*
Lip
Nose
Skin*
Steel
Vertical Dimension
Steel