4804 Defining the Ideal Nasolabial Angle

Monday, May 9, 2011: 11:16 AM
Bryan Armijo, MD1, Matthew Brown, MD1 and Bahman Guyuron, MD, FACS2, (1)Plastic Surgery, University Hospitals/ Case Medical Center, Cleveland, OH, (2)Plastic Surgery, Case Western Reserve Universtiy, Cleveland, OH

The nasolabial angle (NLA) serves as an important soft tissue cephalometric parameter for the determination of tip rotation.  The NLA is measured as the angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfurt horizontal while intersecting subnasale.  An arbitrary range of 90 – 120 degrees for the NLA is usually stated in the literature, with women having angles more obtuse than that of men.  However, these values are arbitrary and based primarily on clinical judgment and not on objective data.  Thus, the purpose of this study is to define the ideal NLA to provide aesthetic and reconstructive surgeons cephalometric guidelines which will yield a more predictable aesthetic result.


Life-sized, lateral photographs of ten men and ten women of various ethnic backgrounds who had undergone a rhinoplasty, performed by the senior surgeon, were selected for the study.  Using Adobe Photoshop CS, the photographs were electronically altered to change the NLA by 4 degrees.  For men and women, these angles were 90, 94, 98, 102, 106, and 110.  The series of 6 altered photos were then placed on a single Power Point slide for each patient in a non-sequential order. These 20 slides were then placed into a single presentation for viewing by the volunteer raters.  Sixteen raters, composed of a variety of plastic surgery attending staff, residents and office staff were asked to evaluate each of the photographs with the various angles and select their top choice, based on the most aesthetically pleasing NLA.


Data analysis was done using the distribution of means of the first preference NLA values based on all sixteen raters. The mean angle for ideal male NLA was 95.96 degrees with a standard deviation of 2.57 degrees.  The mean angle for females was 97.7 degrees with a standard deviation of 2.32 degrees for females.  Based on these standard deviations, the ideal male NLA would be 93.4-98.5 degrees, and for females, 95.5-100.1.


Our results indicate a much closer range of NLA between men and women than previously reported in the literature.  This study is the first of its kind to objectively define the ideal aesthetic NLA.  In addition, the ideal NLA for women was found to be less obtuse than previously thought.  By defining the ideal range of the NLA, we will contribute to cephalometric guidelines for aesthetic and reconstructive plastic surgeons who wish to attain the most aesthetically pleasing results for their patients.  The second phase of this study is currently underway and will involve members from the Rhinoplasty Society rating the same NLA angles to assess if an “experts” ideal NLA differs.

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