Varied definitions of nasolabial angle: Searchingfor consensus among rhinoplasty surgeons and an algorithm for selecting the ideal method

Background: The nasolabial angle (NLA) is an important aesthetic metric for nasal assessment and correction. Although the literature offers many definitions, none has garnered universal acceptance. Methods: To gauge the consensus level among practitioners, surveys were administered to a convenience sample of rhinoplasty surgeons soliciting practice characteristics, self-assessment of rhinoplasty experience and expertise, and preferred NLA definition. Choices of NLA definition included the angle between: (A) columella and line intersecting subnasale and labrale superius; (B) columella and line tangent to philtrum; (C) nostril long axis and Frankfort perpendicular; and (D) nostril long axis and vertical facial plane. Results: Of the 82 total respondents, mean age was 50 years (range, 30-80years), and mean professional experience was 17 years (range, 0-67 years). Nineteen described themselves as novice rhinoplasty surgeons, 27 as intermediates, and 36 as experts. Mean number of lifetime rhinoplasties performed was 966 (range, 0-10,000). Twenty respondents (24%) agreed with definition A, 27 (33%) with B, 16 (20%) with C, and 13 (16%) with D. Six chose "other," offering their own explanations of NLA. Self-identified novices were more likely to prefer definition D than were experts (P = 0.009). Conclusions: No majority consensus was reached regarding the definition of NLA. Each method has its benefits and drawbacks, and establishing a single one may be unnecessary and even counterproductive in some cases. Having options available means that surgeons can tailor to each encounter, as long as they adopt a systematic methodology. We submit an algorithm to facilitate this effort.