The Relationship of Facial Animation to Smile Aesthetics

Abstract

The aesthetics of a smile have been shown to be related to the symmetry of the smile, the curvature of the upper lip, and the arc of curvature of the lower lip to the incisal edges of the upper teeth. The present study quantitatively compares the magnitude of facial animation (as determined by the Johnson Maximal Static Response Assay) to the aesthetics of a smile in 25 subjects. The assay (software) calculates two-dimensional facial movement changes from the frontal view, as measured by the relative change in position of seven facial landmarks. Smile shape and lip fullness were also categorized. Lip fullness was the only variable found to correlate with the aesthetics of a smile. The magnitude of facial movement, smile shape, and gender did not correlate with aesthetic ratings.