[Preliminary study on analysis method of spontaneous smile and application].

OBJECTIVE

To investigate the smile esthetic elements of Chinese Han-nationality female based on high definition (HD) digital camera with computer-image measuring technique.

METHODS

HD digital camera was used to capture spontaneous smile process combined with computer-image measuring technique to establish the analysis method of smile. Ninety-nine Han-nationality female with normal gingiva, aged from 20 to 30 years were recruited. The lip-incisor edge distance, gingival display were measured. The data was statistically analyzed.

RESULTS

A standard and objective method to analyze spontaneous smile was established. Forty-three percent (43/99) of the subjects studied were classified as having a high smile and average smile respectively, 13% (13/99) as having a low smile. Gingival display accounted for (1.34 ± 0.98) mm in high smile type.

CONCLUSIONS

Average smile and high smile type were most common in the Chinese Han-nationality female studied.