Varied Definitions of Nasolabial Angle: Searching for Consensus Among Rhinoplasty Surgeons and an Algorithm for Selecting the Ideal Method

Overview

The nasolabial angle is a standard measure used in planning and assessing rhinoplasty. The literature offers several definitions and none is universally accepted. The authors surveyed a convenience sample of rhinoplasty surgeons about their practice, their self-rated expertise and which definition they use.

Sections of note

• 82 respondents, mean age 50 years. Mean professional experience 17 years, range 0 to 67.
• 19 were self-described novices, 27 intermediates and 36 experts. Mean lifetime rhinoplasties performed was 966, range 0 to 10,000.
• Four definitions were offered, using the columella or the long axis of the nostril, measured against the upper lip, the philtrum, the Frankfort perpendicular or the vertical facial plane.
• Choices: definition A 20 respondents (24 percent), B 27 (33 percent), C 16 (20 percent), D 13 (16 percent). Six chose other and gave their own definitions.
• Self-identified novices were more likely than experts to prefer definition D, p = 0.009.
• The authors conclude no majority consensus exists, propose that a single definition may be unnecessary or counterproductive, and submit an algorithm for selecting a method.

What it means for a patient

• A number quoted for a nose's angle depends on which definition was used, so figures from different sources are not directly comparable.
• The same nose can be described as having different angles by two surgeons, both correct by their own definition.
• The authors argue for choosing a method to suit the case rather than fixing one standard, provided the surgeon is systematic about it.
• This is a survey of opinion from a convenience sample of 82 surgeons, not a study of patients, and it establishes no correct definition.

Why this paper matters

Comparing published rhinoplasty results assumes shared measurement, and this survey shows that assumption fails for one of the most cited measures. That has direct consequences for interpreting outcome studies. Whether an agreed definition would improve results, or whether flexibility is genuinely preferable, is unresolved.

Terms

• Nasolabial angle: the angle between the base of the nose and the upper lip, a measure of tip rotation.
• Columella: the strip of skin between the two nostrils.
• Philtrum: the vertical groove in the middle of the upper lip.
• Frankfort plane: a standard horizontal reference line across the head, used in facial measurement.
• Convenience sample: participants recruited because they were readily available, not selected at random.