Microcalipers were used to measure the true lower vermillion midpoint to lateral commissure distance at full smile in 10 normal individuals (20 hemismiles). Clinical photographs of the same patients at full smile were imported into Photoshop, and, after a brief SMILE technique tutorial, 3 independent lay testers were asked to measure the lower vermillion midpoint to the lateral commissure distance on each side in millimeters. Having measured the iris-scale–corrected x- and y-axes, each tester calculated the hypotenuse (z) on each side using Microsoft Excel software (Redmond, Washington). Class correlation coefficients were calculated for each tester's measured distances and compared with the true excursion. A strong correlation was found for each tester, respectively (R = 0.99, 0.96, and 0.99). Each tester's calculated excursion distances over 20 independent measurements were compared against each other to test intertest reliability. There was strong correlation between the measurements of all 3 testers (tester 1 to tester 2, R = 0.96; tester 2 to tester 3, R = 0.98; tester 1 to tester 3, R = 0.88). The following week, to determine intratest reliability, the same 3 testers repeated the analysis of 4 randomly chosen photographs. The results of their second analyses were compared with their first, and a strong correlation was found for each tester (R = 0.99, 0.99, and 0.99).