Nasal analysis before surgery

What repeats

Four findings that hold across the literature.

The measurement set is large and it is written down

A review of the published measurements used in rhinoplasty found 61 facial features, made up of 45 points, 5 lines, 8 planes and 3 areas, and 122 measurements, made up of 48 distances, 57 angles and 17 ratios. No surgeon uses all of them. The point of the compilation is that the vocabulary is fixed, so two surgeons describing the same nose describe it the same way.

Rests on: Celikoyar et al., the compilation · and nasal anatomy.

The ideal ratios and the surgeon's own drawing do not agree

Ninety-seven consecutive patients had their photographs measured by a standard anthropometric analysis and separately altered by the surgeon to what he judged an attractive nose. The surgeon's drawings averaged a nasal length 76.1 percent of midfacial height, tip projection 57.7 percent of nasal length and radix projection 24.3 percent of nasal length. Against the formula the surgeon barely shortened the nose, at 100.3 percent of the original length where the formula called for 88.2 percent, and raised the radix less, at 100.5 percent against 109.3 percent.

Rests on: Lisiecki and Gilman, formula against drawing.

The proportions people find attractive are not one set of numbers

Farkas and colleagues measured the neoclassical canons against real faces and found each one fits a minority. In 153 young adult North American Caucasians the two that held most often were horizontal: interorbital width equal to nose width, in 40 percent, and nose width equal to a quarter of face width, in 37 percent. Repeating the tests in 100 young adult Afro-Americans against 103 Caucasians, and in 60 each of Chinese, Vietnamese and Thai adults against 60 Caucasians, returned different frequencies again, with the canons valid in 16.7 to 36.7 percent of the Caucasian group and in 1.7 to 26.7 percent of the Asian groups. Anthropometry of attractive women from seven regionally defined groups found the ideal nasal proportion varies with background, and the classical canons hold only within a narrow population. The current argument in the literature is to describe the nose by its measured morphology and drop broad demographic labels.

Rests on: Farkas et al., the canons measured · Farkas et al., Afro-American faces · Le and Farkas, Asian and Caucasian faces · Saad et al., the canons revisited · Craig et al., morphology over identity.

A crooked nose usually comes from asymmetric growth, not from injury

Of 76 primary rhinoplasty patients, 9 percent reported previous nasal trauma, 68 percent had deviated nasal bones, 46 percent had deviated tips, 70 percent had asymmetric midfaces and 36 percent had deviated chins. In patients with no trauma history the nasal bones deviated towards the underdeveloped side of the midface in 53 percent of cases. This is why the analysis covers the whole face and not the nose alone.

Rests on: Scott and Pearlman, deviation and facial asymmetry · and the deviated nose.

By what part of the assessment it belongs to

Four parts, done in order, at the first consultation.

The photographs

Standard views are the frontal, both obliques, both laterals and the base, taken at a fixed distance with fixed lighting, because the same nose measures differently when any of that changes. Lighting is not neutral: rated by 10 lay judges across 40 patients, lighting from above showed more deviation and irregularity than standard anterolateral lighting in 30 pairs, 75 percent, with mean ratings of 2.47 against 1.86.

Rests on: Kim and Most, photodocumentation · Tasman, lighting from above · Fernandez-Pellon et al., lighting comparison.

The measurements taken from them

Angles and ratios are read off the photographs, usually in software. Camera distance changes the answer. In 30 volunteers, nasal length measured 6.4 percent longer in a smartphone photograph taken at 12 inches than in clinical photography, and the ratio of nostril base width to face width fell 10.8 percent, so a nose looks larger and longer in a selfie than it is.

Rests on: Pressler et al., selfies against clinical photographs · Taritsa et al., LED lighting.

The simulated image

Morphing is where you and the surgeon agree what the result should look like. In one consecutive series, 13.2 percent of patients were turned down for surgery because no agreement was reached during the simulation. Of the 290 accepted, 178, or 53.3 percent, went ahead. Of those turned down 57 percent were not satisfied with the simulated result, against 16 percent of those who were operated on.

Rests on: Lekakis et al., morphing as a selection tool · Golan et al., morphing the frontal view.

The plan that comes out of it

The output is a written plan tied to named structures. The national guideline sets what should be assessed and documented before surgery, including breathing, and what should be recorded afterwards.

Rests on: the clinical practice guideline · and nasal airway obstruction.

What to ask about the analysis of your nose

Questions the evidence supports asking.

Are these photographs taken the same way every time

Ask whether the follow-up photographs will use the same camera, distance and lighting as today's. If they do not, the comparison shows the lighting rig as much as the surgery. Bring your own phone photographs if you like, and expect the surgeon to measure from the clinical set.

Rests on: Kim and Most · Pressler et al..

Is the simulated image a promise

It is not. Treat disagreement during the simulation as information: it predicted who went ahead and who did not in the largest published series, and a surgeon who cannot reach agreement with you on the screen has a reason to decline.

Rests on: Lekakis et al. · and the psychology of rhinoplasty.

Who made the simulation, the surgeon or the software

Both are in use. Shown to 97 of 122 doctors, simulations made by software matched the assessors' judgement 68.4 percent of the time against 77.3 percent for the surgeon's own. In a separate test, participants told a generated image from the real postoperative photograph with an accuracy of 52.5 percent, which is chance.

Rests on: Chinski et al., an artificial intelligence tool · Knoedler et al., generated outcome images · Eldaly et al., systematic review.

Is three-dimensional imaging worth paying for

A meta-analysis of 12 studies covering 595 patients found surgeons more satisfied with three-dimensional planning and the method more precise, no difference in reoperation rate or operating time, and a higher cost. Nasal function results were inconsistent.

Rests on: Werathammo et al., meta-analysis · and the cost of rhinoplasty.

Does my age change what the measurements will do

In 243 patients grouped by decade, nasal length, tip projection and midfacial height changed significantly between three months and two years in the groups over 40, and the largest change was midfacial height in the oldest group at 5.5 mm.

Rests on: Ince et al., the impact of age · and recovery.

The terms, defined

The words used in a rhinoplasty consultation.

• Anthropometry: measuring the face by fixed landmarks, distances, angles and ratios. [33855336]
• Landmark: a named point on the face, such as the radix or the tip-defining point, that every measurement is taken from. [33855336]
• Nasolabial angle: the angle between the columella and the upper lip on the profile, reported as tip rotation. [31219525]
• Nasofrontal angle: the angle at the root of the nose between the forehead and the dorsum. [31219525]
• Radix: the root of the nose, where it meets the forehead. [34498141]
• Goode ratio: tip projection expressed as a fraction of nasal length. [34498141]
• Morphing: altering a photograph of your nose to show the planned result. [32092769]
• Stereophotogrammetry: building a three-dimensional surface model from several cameras firing at once. [39038800]
• Midfacial height: the vertical distance across the middle third of the face, used as the denominator for nasal length. [37578466]

Where else this is documented

Sources outside the journals, each one free to read.

The national guideline

The American Academy of Otolaryngology published a clinical practice guideline on nasal form and function after rhinoplasty, with a plain language summary written for patients. It states what a surgeon should assess and record before operating.

Rests on: the clinical practice guideline · the plain language summary.

The surgeons' own textbook chapters

Rhinoplasty Archive, the free online rhinoplasty textbook edited by Daniel G. Becker, carries a photography chapter, a chapter defining the gender angle, and a patient guide.

• Photography for Rhinoplasty
• Definition of Gender Angle in Caucasian population
• A Patient's Guide to Rhinoplasty

The reference summary

Anatomy, Head and Neck, Nose and Rhinoplasty in StatPearls, on the National Library of Medicine's Bookshelf, name the structures the measurements refer to, in full text at no charge.

The societies

• American Society of Plastic Surgeons, patient information.
• American Academy of Facial Plastic and Reconstructive Surgery, patient information.
• The Rhinoplasty Society, the surgeons' body, with its member directory.

The trials in progress

Normative measurement is still being collected in registered studies.

• Prevalence of Variants of Nasal Cavity and Nasal Septum in Nepalese, completed, 343 participants.
• Nasal Septum Deviation May Affect Facial Morphologic Parameters, unknown status, 50 participants.

What is not settled

• The classical proportion canons are treated as guidance rather than targets, and the papers testing them keep finding they fit a minority of any population. [3883374] [10890944] [11891603] [29273934] [42312605]
• The formula-driven plan and the surgeon's own drawing disagree on nasal length and radix projection in the one study that compared them directly. [34498141]
• Photographic measurement depends on camera distance and on lighting, and no single lighting standard has been agreed. [32614619] [33742427] [41136704]
• Simulated images are used to set expectations and are not held to any accuracy standard. The published check on generated images tested whether people could spot them, not whether they matched the surgery. [38777929] [34051703]
• Three-dimensional imaging raises surgeon satisfaction and precision without a measured change in reoperation rate, and the functional results conflict. [39038800]