Chin augmentation with rhinoplasty

What repeats

Five findings that hold across the literature.

Most people booking a rhinoplasty have a chin that measures off

One hundred and eight consecutive primary rhinoplasty patients were assessed with photographs and soft tissue cephalometrics. Ninety-seven showed some degree of objective chin dysmorphology: 63 with a small chin, 15 with a large one, 14 with both in different planes, and 41 with asymmetry. All were offered correction. Eleven accepted, five taking an osseous genioplasty with a mean advancement of 7.8 mm and seven taking fat grafting at a mean of 4.4 cc.

A British series read the same question off the photographs alone. The preoperative pictures of 100 consecutive rhinoplasty patients were assessed by two registrars using the Silver, Legan, Merrifield and Gonzales-Ulloa methods, and 94 were suitable for analysis. The share meeting criteria for augmentation depended on which method was used: 17 to 62 percent of the men and 42 to 81 percent of the women. Judged on three or more methods at once, 21 percent of men and 58 percent of women qualified.

Rests on: Coombs et al., chin dysmorphology in the primary rhinoplasty population · Ahmed et al., assessment of the chin in rhinoplasty patients · rhinoplasty psychology.

Two operations do the work, and one of them does more than move the chin forward

The accepted methods are an alloplastic chin implant placed against the front of the jaw, and a sliding genioplasty, which cuts the lower edge of the jawbone and fixes it in a new position. Both treat a chin that is set back. Only the genioplasty also corrects asymmetry, a chin that projects too far, and a chin that is too tall or too short.

The two have been compared twice. In the first comparison, 76 patients had an augmentation genioplasty, 34 by osteotomy and 42 by implant. Both groups were highly satisfied, satisfaction was slightly higher after the osteotomy, and morbidity was the same. The soft tissue response was more predictable after the osteotomy and the cervicomental angle improved more. In the second, 345 patients with microgenia were treated by one team, 135 with sliding genioplasty, 60 with an implant and 150 with hyaluronic acid, and followed for three years. Sliding genioplasty gave the more predictable and more stable long-term result of the three.

Rests on: Guyuron and Raszewski, osteoplastic against alloplastic genioplasty · Bertossi et al., chin microgenia compared · Sykes and Suarez, chin advancement, augmentation and reduction.

How far the chin has to move decides which operation is used

Forty-nine patients with chin retrusion between 2.5 and 6 mm were treated by one surgeon. Fat grafting alone covered advancements of about 2 mm, and fat combined with sliced septal cartilage under the muscle covered about 4 mm. Beyond 6 mm the paper puts the work back with implants or an osseous genioplasty. The implant group had the largest change in the Legan angle, the measured angle of facial convexity.

Rests on: Selamioglu and Kucuker, hybrid chin advancement.

The combined operation holds its position at three years

Ninety patients had open rhinoplasty and genioplasty in one sitting and were measured three years later at soft tissue pogonion. Among the augmentations, 22 patients moved 4 to 6 mm vertically and 25 moved 6 to 8 mm sagittally, and 52.4% showed no measurable change at three years. No patient lost more than 1 mm.

Rests on: Bertossi et al., combined rhinoplasty and genioplasty · recovery after rhinoplasty.

Patients and surgeons look at different parts of the profile

Twenty-six patients and 13 experienced surgeons viewed 21 standard lateral profile photographs while their eye movements were recorded. Both groups spent most of their time on the nose. Patients held the nasal tip longer than surgeons did, and surgeons held the radix longer than patients did. Neither group's attention settled on the chin.

Asked to score the profile rather than look at it, the same two kinds of observer part company again. Thirty patients with a convex profile and a nasal hump had their cephalograms traced and altered by software into silhouettes in four versions: unchanged, rhinoplasty, genioplasty, and both. Six orthodontists and six laypersons rated them. Both changes together scored highest at 3.9, rhinoplasty alone 3.5, genioplasty alone 2.4 and no change 2.13. Orthodontists did not rate the genioplasty above no change at all.

Rests on: Ugurlu et al., visual attention in rhinoplasty · Sadeghian et al., simulated rhinoplasty and genioplasty rated · nasal anatomy.

By what the profile needs

The chin is one of several things that change the same view.

The chin sits behind the lip line

Microgenia is the small chin with a normal bite, the commonest finding in the rhinoplasty population and the one an implant or a forward slide is designed for.

Rests on: Coombs et al. · Sykes and Suarez.

The chin is too large or off the midline

Reduction and repositioning are genioplasty work rather than implant work, because bone has to move in more than one direction. Asymmetry was present in 41 of the 108 patients assessed.

Rests on: Sykes and Suarez · Coombs et al..

The jaws are out of position, not the chin

Where the bite is wrong, the chin follows the jaw. In 118 patients with malocclusion, dorsal preservation rhinoplasty was done in the same sitting as bimaxillary orthognathic surgery, taking a mean of 207 minutes, with complications in 12.7%.

Rests on: Raffaini and Arcuri, preservation rhinoplasty with orthognathic surgery · preservation rhinoplasty.

The chin is filled instead of operated on

Hyaluronic acid injected at the front of the chin is the non-surgical route, and it is the only one of these methods tested against a control group. One hundred and ninety-two adults with chin retrusion were randomised three to one, 144 treated at the start and 48 six months later. At six months, 56.3% of the treated group had improved by at least one point on the Allergan Chin Retrusion Scale against 27.5% of the controls, and the benefit was still visible at twelve months. Tenderness was reported by 81.1% and firmness by 75.1%. One participant stopped the study with facial cellulitis and injection site inflammation, both of which resolved. A systematic review of eight studies covering 917 filler patients found two major complications and no vascular occlusion.

Rests on: Beer et al., chin augmentation with VYC-20L · Ou et al., systematic review of hyaluronic acid chin augmentation · Bertossi et al..

The shortfall is soft tissue rather than bone

Fat adds contour without a fixed implant, and seven of the eleven patients who accepted chin correction in the Cleveland series had fat rather than bone work. The same reasoning has been applied at the other end of the profile, where fat grafting to the forehead was studied as an adjunct to rhinoplasty.

Rests on: Selamioglu and Kucuker · Coombs et al. · Demirel, forehead contouring.

What to ask about chin surgery with rhinoplasty

Questions the evidence supports asking.

Does my chin need to move, or only my nose

Ask for the cephalometric measurement rather than an opinion. Rhinoplasty measurably narrows the range of profiles a surgeon produces: across 145 patients from three surgeons, postoperative photographs were 17.58% more similar to one another than the preoperative ones.

Rests on: Coombs et al. · Khaw and Lu, the homogenising effect of primary rhinoplasty.

Implant or sliding genioplasty, and how many millimetres

Ask which one, why that one for this chin, and what the planned advancement is as a number. An implant is a shorter operation with a device left in place. A genioplasty moves the patient's own bone and can correct height and asymmetry at the same time. Mean advancement was 7.8 mm in the osseous genioplasty group of the Cleveland series, against thresholds of about 2 mm for fat and about 4 mm for fat with cartilage in the hybrid series.

Rests on: Sykes and Suarez · Selamioglu and Kucuker · Coombs et al..

If it is an implant, what are the removal and numbness rates, and what happens to the bone

A systematic review pooled 39 articles and more than 3104 implant patients. Numbness was reported least often with silicone at 0.4%, against 20.1% for high-density porous polyethylene and 3.2% for expanded polytetrafluoroethylene, and rates of malposition, infection, extrusion, revision and removal did not differ by material. The surgical approach did change them. Compared with placing the implant under the periosteum, the dual-plane technique had more malposition, 2.8% against 0.5%, more revision, 4.7% against 1.0%, and more removal, 4.7% against 1.1%, but less numbness, 1.9% against 10.8%. An incision inside the mouth led to more removals than one under the chin, 1.5% against 0.5%, and less asymmetry, 0.7% against 7.5%. The bone under the implant gives way: a review of 28 studies found resorption common, most reporting a mean under 2 mm, with most follow-up under five years.

Rests on: Liao et al., complications following alloplastic chin augmentation · Yeung and Wong, mandibular bone resorption after chin augmentation · revision rhinoplasty.

How is the profile measured and planned

Ask which angle is being used, because the profession has not agreed on one. Of 82 surgeons surveyed on the definition of the nasolabial angle, the most popular answer took 33%. Asked what the ideal angle is, 197 respondents averaged 97.1 degrees for a male face and 109.5 for a female one. Photographic morphing is the published method for showing a patient the planned profile.

Rests on: Harris et al., varied definitions of nasolabial angle · Alshawaf et al., preferred nasolabial angle · Apaydin and Ozucer, precision profileplasty.

Will my tip rotation still be settling when the chin is judged

Tip rotation moves for months after surgery. In 111 consecutive patients the nasolabial angle rose 9.3 degrees in the first week and was still 4.94 degrees above baseline at six months, while the columellar-philtral angle had returned to its starting value.

Rests on: Brennan et al., angles over time after rhinoplasty · revision rhinoplasty.

The terms, defined

The words used about the chin and the profile.

• Microgenia: a small chin with a normal bite. [26616715]
• Retrognathia: the lower jaw set back, which carries the chin with it. [26616715]
• Sliding genioplasty: cutting the lower edge of the jawbone and fixing it in a new position. [26616715]
• Alloplastic chin implant: a manufactured implant placed against the front of the jaw. [26616715]
• Pogonion: the most forward point of the chin, the landmark stability is measured at. [23493992]
• Legan angle: the measured angle of facial convexity, used as the endpoint for chin advancement. [38858246]
• Nasolabial angle: the angle between the columella and the upper lip, with four competing definitions. [27482491]
• Columellar-philtral angle: a second rotation measurement that behaves differently over time. [35130565]
• Profileplasty: treating nose and chin as one operation on the side view. [29710239]
• Allergan Chin Retrusion Scale: the graded scale used as the endpoint in the filler trial. [33347003]
• Bone resorption: the loss of bone under a chin implant, measured on radiographs. [35402503]

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 requires the surgeon to ask what the patient expects and to record whether that expectation is achievable, which is where a chin discussion belongs.

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

The surgeons' own textbook chapter

Rhinoplasty Archive, the free online rhinoplasty textbook edited by Daniel G. Becker, carries a chapter on this operation, written for surgeons.

• Chin Augmentation Surgery

The reference summaries

• Alloplastic Chin Augmentation in StatPearls, free full text on the National Library of Medicine's Bookshelf.
• Facial Implants in StatPearls, covering the implant materials and their failure modes.

The societies

• American Society of Plastic Surgeons, chin surgery patient information.

The trials in progress

• Patient-specific Alloplastic Chin Implant Versus Computer Guided Genioplasty, completed, 20 participants.
• Autogenous Fat or Onlay PEEK Augmentation Versus Sliding Genioplasty for Correction of Deficient Chin, status unknown, 12 participants.

What is not settled

• No trial compares implant against sliding genioplasty for the chin that accompanies a rhinoplasty. The two published comparisons are retrospective and each comes from a single team, and the two registered trials making that comparison are small and neither has reported. [26616715] [2399851] [26130400]
• How far the bone goes on receding under an implant is unmeasured past five years. The review found most series stopping before then. [35402503] [36880789]
• The thresholds that route a patient to fat, to cartilage, or to bone come from one surgeon's series of 49 patients. [38858246]
• Long-term stability is reported at three years in 90 patients, by the surgeons who did the operations. No independent series follows the combined operation further. [23493992]
• What observers make of a corrected chin has been tested only on silhouettes. Six orthodontists and six laypersons rated a simulated change, while eye-tracking on real photographs found attention on the nose in both groups. [29959302] [41413747]
• Chin dysmorphology was found in 89.8% of rhinoplasty candidates, and 11 accepted treatment. Why the rest declined is discussed rather than measured. [37430011]