抄録
The purpose of this study was to investigate the relationship of lips to maxillary anterior teeth of normal dentulous subjects. This relationship will help to determine proper functional and aesthetical anterior tooth arrangement for prosthesis.
Seven selected pointts were placed on the surface of lips and three points were placed on the labial surface of the anterior teeth of 96 subjects.
The coordinates of these points were surveyed with incisal point and maxillary cuspid as the origin by 35mm nonmetric SLR camera as a three dimensional measurement system.
The findings were as follows:
1. When the incisal point was taken as the origin of the three dimensional coordinates, the coordinates of labrale superius were (-0.2, 12.7, 10.1mm), the coordinates of labrale inferius were (-0.2, -7.1, 11.3mm).
2. When the each maxillary cuspid point was taken as the origin of the three dimensional coordinates, the coordinates of the left corner of the mouth were (-5.8, -5.4, 4.4mm), and the right corner of the mouth were (6.1, -4.8, 4.3mm).
3. In the X-coordinate, the shift of cuspid point and the ala of the nose was on the average 0.3mm on the right side and -0.7mm on the left side. When viewed from the frontal aspect these two points were almost coincidental.
4. The mean measurement of distance between cuspid points was 39.1mm, and the average distance between the corners of the mouth was 51.2mm. These two measurements showed a significant correlation.
