Redefining the Ideal Nasolabial Angle

Abstract

The nasolabial angle is the angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal plane while intersecting subnasale. Previous analysis by the authors' department yielded closer ranges between men and women of 96 and 98 degrees, respectively. This study further refines the ideal nasolabial angle using the opinions of a highly select group of seasoned rhinoplasty surgeons. Lateral photographs of 10 men and 10 women of various ethnic backgrounds who had undergone a rhinoplasty were studied. The photographs were digitally altered to various angles. Members of the Rhinoplasty Society evaluated the photographs. Raters selected their top choice based on the most aesthetically pleasing nasolabial angle. In addition, they were asked to estimate the angle of the photograph they selected as most ideal. Data analysis was performed using the distribution of means of ideal nasolabial angle values. Based on the 95 percent confidence interval for the ideal means, the ideal nasolabial angle would be 93.9 to 97.3 degrees for male subjects and 96.8 to 100.2 degrees for female subjects. Twenty-four raters provided angle estimations; the mean ± SD angle was 2.76±2.49 degrees larger than the actual angle. The authors' results were consistent with their previous findings, indicating a much closer range of nasolabial angle between men and women than previously reported in the literature. The overestimation in the nasolabial angle versus actual may be one factor accounting for the difference between the authors' findings and the previously accepted standards.