Abstract
In selecting and arranging artificial teeth, it is necessary to consider the relationship between the tooth and lips. The relation of high and low lip line to incisal edge has been a standard for the selection and arrangement of artificial teeth. However, form and movements of lips are variable because of their softness and elasticity.
The purpose of our investigation was to evaluate movements of lips three-dimensionally (3 D). We used the 3 D Image Scanner (3 D-VMR-201: Unisn Inc.) for measuring the surface shape of the face. This machine was capable to measure surface shape at high speed without touching the object.
We recorded and measured the surface shape of lips in function (smile, pronunciation etc). The movements of the measuring points were calibrated in order to compare each data of the surface shapes in different functions among the dentate subjects. Further, we examine the influence of prosthetic appliance such as bite raising assuming prosthetic treatment for edentate subjects.
The following results were obtained:
1. In function times, upper lip moves rearwards and upwards. Lower lip moves rearwards and downwards. Lower lip movements were larger than those of upper lip.
2. The influence of bite raising appeared mainly in upper and lower lip, and those of changing labial surface position appeared in upper lip and both corners of the mouth.
