Submental liposuction and neck contouring

What it is

Neck fat lies in two layers. The fat above the platysma, the thin muscle sheet under the skin of the neck, is what liposuction reaches; the fat beneath the platysma sits in three compartments between that muscle and the muscle floor of the mouth, and can only be treated through open surgery (PMID 33002983, PMID 20679840).

The balance between the two layers changes with age and sex. Older women have less fat above the platysma than young women, while the deep fat does not change, and in older women the remaining surface fat collects in the middle of the neck (PMID 33002983). Women carry more of their neck fat above the platysma and men more beneath it (PMID 36967478). In an older neck, fullness is therefore less often surface fat alone, and removing surface fat and tightening skin and muscle does not correct deep fat, large salivary glands or bulky digastric muscles (PMID 36563673).

Where it came from

• In 1980 Dedo published a classification of the neck to plan facelift surgery (PMID 7432071).
• Liposuction reached the neck in the 1980s. In 1984 Newman paired liposuction under the chin with a firm chin implant to tighten the skin and sharpen the angle between chin and neck, widening the suction with age and adding a facelift when the skin was loose (PMID 6732587). In 1990 Chrisman described liposuction as an aid that made the facelift easier and safer (PMID 2379335).
• In 1991 Kamer published a graduated approach that matches the operation to the skin, fat and muscle (PMID 1986759), and in 1993 Perkins described a planned second tightening under the chin for necks that sag again after a facelift (PMID 8427681).
• Tumescent local anesthesia let dermatologic surgeons perform neck liposuction safely in large series without general anesthesia (PMID 29320585, PMID 22931548).
• Laser and radiofrequency energy were added to liposuction to tighten skin (PMID 16453321, PMID 27622118), and trials published in 2016 tested an injectable that dissolves fat and a cooling device that freezes it, both without incisions (PMID 26673433, PMID 26607045).

Who it suits

• Younger patients with fat under the chin and good skin tone. Suction under the chin alone is enough (PMID 6732587).
• Older patients with fat spread along the jaw and less skin tone. Suction extends to the sides of the neck; when the skin is loose, a facelift is combined with liposuction (PMID 6732587). Kamer's approach matches skin, fat and muscle findings to the operation (PMID 1986759).
• A small chin. Chin projection tightens the skin under the chin and improves the neck angle (PMID 6732587); adding liposuction to a chin advancement suits mild to moderate cases (PMID 39656443).
• People who want no incision. Injections and fat freezing reduce fat under the chin without surgery (PMID 26673433, PMID 26607045), in people with mild fat and in those with a great deal of it (PMID 30998531).
• Choosing among the options. Treatments run from devices applied to the skin, through injections and liposuction, to a deep neck lift, and the choice follows what lies under the chin (PMID 40164115).
• Not suited to liposuction alone: fat beneath the muscle, large glands, digastric bulk and neck bands (PMID 36563673).

How it is done

Liposuction

• Under tumescent local anesthesia, a thin cannula removes fat through small incisions (PMID 22931548, PMID 29320585). The authors of one large series advise closer monitoring after neck liposuction than after body liposuction (PMID 22931548).
• In wide-undermining liposuction the surgeon frees the skin across the neck and leaves a thin layer of fat on it, so the skin redrapes smoothly (PMID 24902909).
• Liposuction can be combined with platysma tightening, laser treatment under the skin or a SMAS lift (PMID 10886268).

A small incision under the chin

• Through a short incision under the chin, the surgeon combines liposuction, wide skin release and tightening of the platysma, as an operation on its own or with a facelift (PMID 12633210). Ultrasound-assisted liposuction with a limited platysma repair treated moderate to advanced necks without removing skin (PMID 18654817).

Chin projection

• A chin implant (PMID 6732587) or a chin advancement (PMID 39656443) gives the skin under the chin a firmer front edge.

Energy-assisted liposuction

• Laser energy delivered through the cannula breaks fat cells and tightens collagen and small vessels (PMID 16453321). Radiofrequency heats the fat and the underside of the skin to tighten it (PMID 27622118, PMID 32004377, PMID 37205298).

Injections

• Deoxycholic acid (Kybella) destroys fat cells and is given in several sessions (PMID 26673433, PMID 27430612). A newer injectable, RZL-012, reduced fat volume on MRI after a single high-dose session in an early trial (PMID 37348516).

Fat freezing

• A cooling applicator held under the chin for an hour kills fat cells; a second session can follow at 6 weeks, and results are judged at 12 weeks (PMID 26607045).

Results and how long they last

• Liposuction with neck tightening. Results were good to excellent in about 9 in 10 patients (PMID 10886268). Wide-undermining liposuction improved the neck contour in every patient without touch-ups (PMID 24902909).
• Radiofrequency-assisted liposuction. Most patients were satisfied in single-surgeon series (PMID 27622118, PMID 37205298); in a larger series about 1 in 5 saw little or no change at 6 months (PMID 32004377). A systematic review found the evidence for radiofrequency under the skin weak: mostly satisfaction scores and photographs, modest satisfaction, and many authors with financial ties to device makers (PMID 35081544).
• Injections. About 2 in 3 treated people improved by at least one grade on a fat scale, against about 1 in 5 on placebo (PMID 26673433, PMID 27430612). The gain held at 3 years in about 4 in 5 responders (PMID 33617632). All trials were industry-sponsored, and a meta-analysis flagged potential bias (PMID 37806137).
• Fat freezing. The fat layer under the chin became about 2 mm thinner, a modest change that blinded reviewers could still see (PMID 26607045, PMID 40473257).
• With a chin advancement. Satisfaction with the chin rose with or without added liposuction (PMID 39656443).

Risks and how surgeons lower them

• After liposuction. About 1 in 8 procedures had an adverse event; three quarters were minor, mostly fluid collections, an uneven surface or asymmetry, and visible neck bands (PMID 42235595). Temporary lower-lip weakness was rare, about 1 in 200 in a large dermatologic series (PMID 29320585), and serious complications were absent in another tumescent series (PMID 22931548). Serious complications, including deaths, have been reported after liposuction under the chin, mostly from bleeding (PMID 39672946).
• Energy devices. Firm areas under the skin followed about 1 in 11 radiofrequency treatments and softened with massage (PMID 27622118). Firmness, nodules, prolonged swelling, numbness and temporary lower-lip weakness were the reported problems in the radiofrequency literature (PMID 35081544), and one patient's airway was obstructed after radiofrequency liposuction of the neck (PMID 36212729).
• Injections. Temporary lower-lip weakness followed about 1 in 25 treated people, mostly mild (PMID 26673433). Scarring under the skin, pain, swelling, numbness and nodules were more common than with placebo (PMID 37806137), and the FDA's device reports include skin necrosis (PMID 39553813).
• Fat freezing. Adverse events followed about 1 in 50 cycles; paradoxical fat growth, a firm enlargement of the treated fat, was rare (PMID 39829238) and in one patient needed a deep-plane neck lift to correct (PMID 40084153).
• Surgery after nonsurgical treatments. Necks previously treated with injections, freezing, radiofrequency or threads showed scarring, lost tissue planes and stiff muscle at surgery; nearly all needed deep neck surgery, operating time rose, and nearly all had contour irregularities afterward (PMID 40712094).

Recovery

• After wide-undermining liposuction under local anesthesia, a dressing stays on for 3 days, and swelling and bruising resolve in a few days (PMID 24902909).
• Recovery from a stand-alone operation through an incision under the chin is shorter than from a facelift (PMID 12633210).
• Fibrin glue placed after liposuction reduced swelling in a randomized study (PMID 39672946).
• Problems after liposuction appeared on average a month or two later, so follow-up visits matter (PMID 42235595).
• Injections: about half of treated people improved after 2 sessions and three quarters after 4 (PMID 26673433).
• Fat freezing: results are judged 12 weeks after the last session (PMID 26607045).

With a facelift

• Liposuction made the facelift easier, and one surgeon reported no hematoma, infection, skin loss, hair loss or nerve injury when he added it (PMID 2379335).
• In Asian patients, laser liposuction added to an extended deep-plane facelift raised satisfaction with the lower face, jawline and the area under the chin; the more fat removed, the higher the satisfaction (PMID 36731512).
• At facelift, open tightening of the platysma gave equal or better neck-angle results than radiofrequency-assisted liposuction in one surgeon's patients (PMID 37992758).
• A planned second tightening under the chin, 6 to 18 months after a facelift, treats a neck that sags again (PMID 8427681).

Questions to ask a surgeon

• Is my fullness fat under the skin, or deep fat, gland or muscle? (PMID 36563673)
• Is my skin firm enough to shrink after liposuction, or do I need skin and muscle tightening? (PMID 6732587)
• Would more chin projection improve my neck? (PMID 39656443)
• How often do your patients have an uneven surface, visible bands or lower-lip weakness? (PMID 42235595)
• If I choose injections or fat freezing now, how would they change a neck lift later? (PMID 40712094)
• How will I be monitored for bleeding after surgery? (PMID 22931548)

Open questions

• Which layer: surface fat falls with age while deep fat does not (PMID 33002983), and liposuction does not reach the structures beneath the muscle (PMID 36563673).
• Energy devices: most evidence is uncontrolled and linked to device makers (PMID 35081544); one comparison with open platysma tightening favored the open repair (PMID 37992758).
• Injections: results last 3 years in most responders (PMID 33617632), against industry-bias concerns (PMID 37806137) and post-market reports of skin necrosis (PMID 39553813).
• Fat freezing: paradoxical fat growth is rare (PMID 39829238) and may need open surgery (PMID 40084153).
• Nonsurgical fat reduction makes later surgery harder (PMID 40712094).
• Complication rates for liposuction come from case series of uneven quality (PMID 42235595).

Terms

• Submental fat: fat under the chin that forms a double chin (PMID 26673433).
• Supraplatysmal and subplatysmal fat: fat above or below the platysma muscle (PMID 33002983).
• Tumescent anesthesia: a large volume of dilute local anesthetic injected before suction (PMID 22931548).
• Submentoplasty: neck surgery through a small incision under the chin (PMID 12633210).
• Cervicomental angle: the angle between the underside of the chin and the neck (PMID 37992758).
• RFAL: liposuction with radiofrequency heating of the fat and skin (PMID 27622118).
• Laser-assisted liposuction: liposuction with laser energy to break fat cells (PMID 16453321).
• Deoxycholic acid (ATX-101, Kybella): injectable that destroys fat cells (PMID 27430612).
• Cryolipolysis: controlled cooling that kills fat cells (PMID 26607045).
• Paradoxical adipose hyperplasia: fat growth in a treated area after cryolipolysis (PMID 40084153).
• Marginal mandibular nerve paresis: temporary weakness of the lower lip (PMID 26673433).

Papers