Hemifacial Microsomia in Adults: The Uneven Jaw, the Small Ear, and What Fat Grafting, Jaw Surgery, Implants, and Ear Reconstruction Can Still Fix

He is 31, a software engineer, and he has had four operations on the left side of his face, the last one at 16. His chin still drifts toward the left. His lips tilt when he smiles. The left cheek is flatter than the right, and the ear he was given at nine, built from his own rib cartilage, sits a little low and has softened over the years. He calls a cosmetic practice to ask about filler and a chin implant. The coordinator books him for a filler consult the following week. Nobody asks whether his teeth meet evenly, whether he snores, or whether anyone ever imaged his neck.

Hemifacial microsomia in adults is a different problem from hemifacial microsomia in children, and the adult version is where cosmetic practices meet it. The condition, increasingly called craniofacial microsomia because it is not always confined to one side, is the underdevelopment of structures that grow from the first and second pharyngeal arches in the embryo: the lower jaw, the cheekbone, the ear, the facial nerve, and the soft tissue over them. Published estimates of how often it occurs range from roughly 1 in 3,500 to 1 in 26,000 births, depending on how strictly it is defined, and it is widely described as the second most common congenital facial difference after cleft lip and palate. What follows covers the medical checklist, the skeleton, the soft tissue, the ear, and the smile.

Hemifacial microsomia in adults: what has to be known before any cosmetic procedure

The short answer: before anything elective, an adult with hemifacial microsomia needs a review of the airway and sleep, the bite, the cervical spine, hearing, and every prior operation on the face, because each one changes what is safe and what will work.

Craniofacial teams describe the condition with the OMENS classification, which grades five structures: the Orbit, the Mandible (lower jaw), the Ear, the Nerve (the facial nerve), and the Soft tissue. An expanded version, often written OMENS-plus, adds problems outside the face, including vertebral, cardiac, and kidney anomalies. The related label Goldenhar syndrome (the oculo-auriculo-vertebral spectrum) is used when eye findings such as epibulbar dermoids and spinal anomalies accompany the facial ones. For a cosmetic surgeon, several items on that list matter more than the face itself.

• The airway and sleep. A short or underdeveloped lower jaw narrows the space behind the tongue. Obstructive sleep apnea is more common, and intubation can be harder. The piece on sleep apnea before cosmetic surgery explains why an undiagnosed snorer is a sedation risk, and the piece on anesthesia choice explains why the anesthesiologist should read the chart before the day of surgery, not during it.
• The cervical spine. Vertebral anomalies, including fused or malformed neck vertebrae, appear in a share of patients across the spectrum. They can limit how far the head can safely be tilted back for intubation. If no one has ever imaged the neck, that is worth knowing before general anesthesia.
• Hearing. The affected ear often has conductive hearing loss from a narrowed or absent ear canal, and some adults wear a bone-anchored hearing device. Its location matters for any surgery near the ear, a point the piece on hearing aids and facial surgery covers in detail.
• The bite. A canted occlusal plane, meaning the line where the teeth meet tilts upward on the affected side, is one of the most common adult findings. It is also the finding that decides whether the answer is filler or jaw surgery, as the next section explains.
• The operative history. Most adults with this diagnosis had childhood procedures: jaw distraction, rib grafts to build a missing joint, ear reconstruction, skin tag removal, corner-of-mouth repair. Scar tissue, hardware, and grafted cartilage all change the next operation. Copies of the operative notes are worth more than any photograph.

A cosmetic practice that does not ask these questions is treating a congenital condition as if it were ordinary asymmetry. The general piece on facial asymmetry is the right reference for the mild, developmental kind most people have. Hemifacial microsomia calls for a team.

The jaw and the chin: when orthognathic surgery is the only honest answer

The short answer: if the bite is tilted, only orthognathic surgery (repositioning the jaws themselves, usually with orthodontics before and after) can level the smile and center the chin; implants and filler can disguise a deficient jaw contour but cannot fix a cant.

Surgeons grade the jaw deficiency using the Pruzansky classification, later modified by Kaban. In Type I, the jaw on the affected side is small but normally shaped. In Type II, the ramus (the vertical back portion of the jaw) and the joint are malformed, with the joint still in a usable position in IIa and displaced in IIb. In Type III, the ramus, the condyle, and the joint are absent. Children with more severe types often undergo distraction osteogenesis, in which a cut bone is lengthened gradually with a device, or a rib graft to build a joint. Both help during growth, and both are well documented in the craniofacial literature to relapse partly as the unaffected side keeps growing. That is why so many adults arrive with residual asymmetry despite having done everything they were told.

At skeletal maturity, the definitive skeletal correction is usually orthognathic surgery. A typical plan combines an upper jaw osteotomy (a Le Fort I, which can level a tilted upper jaw), osteotomies of the lower jaw to move it toward the midline, and often a sliding genioplasty to center the chin. Orthodontic work before surgery lines the teeth up so the jaws can be moved into a stable bite. The piece on orthognathic surgery versus jawline procedures explains the distinction in general terms, and the piece on braces and aligners before facial surgery covers sequencing with dental work. Patients with jaw joint pain or clicking should read the piece on TMJ disorder and facial surgery first, because an underdeveloped joint behaves differently under load.

Virtual surgical planning has changed this work. Surgeons now plan the moves on a three-dimensional model built from a CT scan and print cutting guides and splints from that model. The piece on 3D imaging in consultations covers the consumer version. In craniofacial surgery the stakes are higher: the plan determines where the bone ends up.

When the bite is already level, or when the patient declines jaw surgery, contour options remain:

• Patient-specific implants. Custom implants made from PEEK or porous polyethylene and designed from the patient's own CT can rebuild a flat jaw angle or a short ramus outline far more precisely than an off-the-shelf shape. The piece on cheek and jaw implants explains the infection and displacement risks, which rise in scarred tissue.
• Chin surgery alone. A sliding genioplasty or chin implant can shift and project the chin, but if the cant remains, a centered chin under a tilted lip line can make the tilt more obvious, not less.
• Reducing the other side. Some surgeons treat the unaffected side as well, with masseter Botox or occasionally bone contouring, to narrow the difference from the full side down. It is a legitimate adjunct, not a substitute.

"Filler can make a short jaw look fuller. It cannot level a tilted bite, and a practice that offers a syringe for a canted smile has not looked inside the patient's mouth."

The cheek and the soft tissue: fat grafting, filler, and when tissue has to be moved

The short answer: for mild to moderate hollowing, staged fat grafting is the workhorse; for severe soft tissue deficiency, a surgeon may move a block of tissue with microsurgery; filler is a reasonable trial but carries extra risk in scarred, previously operated tissue.

Even after the skeleton is corrected, the soft tissue on the affected side is often thinner: less fat, less muscle bulk, sometimes a hollow in front of the ear where the parotid region should be fuller. Bone moved into position cannot fill what was never there.

Fat grafting is the most common adult answer. The surgeon harvests fat by liposuction elsewhere, purifies it, and injects it in small threads across many layers. The piece on fat transfer to the face covers the procedure, and the piece on fat graft survival explains why a meaningful share of the injected volume is resorbed. In congenital deficiency, especially over scar, that share can be larger, which is why the craniofacial literature in journals such as Plastic and Reconstructive Surgery describes serial sessions spaced months apart rather than one large transfer. Patients should expect two to four rounds and should be told that up front, along with the risks of lumps, cysts, and fat necrosis. For fine surface irregularities, smaller-particle versions known as microfat and nanofat are sometimes used as a finishing step.

The closest relative in the journal's archive is acquired facial wasting. The piece on facial lipoatrophy and Parry-Romberg syndrome covers progressive one-sided atrophy, which is a different disease with a similar soft tissue problem, and the piece on dermal-fat grafts describes the option of placing a solid block of dermis and fat when injected fat will not hold.

When the deficit is too large for fat grafting, the reconstructive option is a flap: tissue from the back, thigh, or abdomen transferred with its own artery and vein and connected to vessels in the neck under a microscope. These flaps add real volume in one stage but can sag over time, can be bulky, and usually need revision. They belong in a hospital with a reconstructive microsurgeon, not a cosmetic suite.

Filler sits at the other end. Hyaluronic acid filler can preview what volume will look like and can be dissolved. In tissue that has been operated on, though, normal anatomy is distorted, vessels may run in unexpected places, and the risk of injecting into a vessel deserves extra respect. The piece on filler and vascular occlusion explains the stakes, and the piece on biostimulatory fillers explains why a product that cannot be dissolved is a poor first choice in a face that will likely need more surgery.

The ear: revising a childhood reconstruction, choosing a framework, or choosing a prosthesis

The short answer: adults can revise or redo a childhood ear reconstruction, choose a porous polyethylene framework, or opt for an implant-retained prosthetic ear; each path has a different trade between natural tissue, precision, and maintenance.

Microtia, an underdeveloped external ear, is one of the defining features of the condition. The three adult routes are well established.

• Autologous rib cartilage. The surgeon carves a framework from the patient's own rib cartilage and places it under the skin in stages. It is living tissue and tends to tolerate minor trauma, but it requires a chest donor site and leaves a chest scar. Adults whose childhood reconstruction has lost definition, sits low, or protrudes poorly can sometimes have the existing framework revised, elevated, or partly rebuilt. Adult rib cartilage is often calcified and harder to carve, which is one reason this route is usually done in childhood.
• Porous polyethylene frameworks. A prefabricated implant framework avoids the rib harvest and is typically covered with a flap of fascia from the scalp. It can be done at a younger age and in fewer stages, but exposure of the implant, especially after trauma, is the main long-term risk, and surgeons who offer it disagree about how often that happens.
• Prosthetic ears. A silicone ear held on with adhesive or with small titanium implants anchored in the skull can look remarkably realistic. It needs replacement every few years and daily care, and implant sites need hygiene. It is also a reasonable choice for patients who have had failed reconstructions or who do not want more surgery.

Two cautions. First, the hearing device and the ear reconstruction compete for the same territory. A bone-anchored implant placed without regard for the future ear can compromise the skin and scalp needed to build one, so the two plans should be made together. Second, the opposite ear matters. Symmetry often improves more by setting back or reshaping the normal ear with otoplasty than by forcing the reconstructed ear to match a prominent one. The piece on cauliflower ear reconstruction covers how cartilage behaves after injury, which is relevant to anyone protecting a reconstructed ear during contact sports.

The smile, the mouth, and the small features that bother people most

The short answer: a weak lower lip on the affected side usually reflects facial nerve involvement and responds to targeted Botox on the stronger side, nerve or muscle procedures in selected cases, or nothing at all; corner-of-mouth scars and remnant tags are among the simplest and most rewarding revisions.

The N in OMENS is the facial nerve, and a meaningful minority of patients have weakness on the affected side, most often in the branch that controls the lower lip. The result is a lip that does not pull down on smiling, which reads as a crooked smile. Treatment borrows from the facial paralysis toolbox described in the piece on synkinesis and facial reanimation: small doses of Botox to weaken the matching muscle on the strong side, which is quick and reversible, or in selected patients a muscle transfer or nerve procedure. The weakness can also coexist with a canted bite, and separating the two is part of the consultation.

Other features are smaller but often more visible in daily life.

• Macrostomia. A widened corner of the mouth, from a lateral facial cleft, is usually repaired in infancy. Adults sometimes want the scar revised or the corner repositioned. The principles overlap with the piece on adult cleft lip revision: lip scars respond well to careful re-excision, and the vermilion border has to line up to the millimeter.
• Preauricular tags and pits. Skin and cartilage remnants in front of the ear, or small pits, are common. Leftover cartilage stumps from incomplete childhood removal can be excised in the office. Pits that drain or get infected may be sinus tracts and need complete removal, not a shave.
• Scars. Adults carry scars from distraction devices, rib grafts, and ear surgery. The piece on scar care covers the routine, and medical camouflage tattooing is an option for flat, pale scars that will not revise further.
• The cheekbone and orbit. When the cheekbone and the eye socket are small, custom implants or fat can rebuild the outline. The piece on old facial fractures covers many of the same tools for a similar contour problem after trauma.

Then there is cost. Corrections of congenital anomalies are often treated as reconstructive rather than cosmetic, and a number of states have laws addressing coverage, but insurers draw the line differently for an adult seeking refinement. The piece on insurance and medical necessity explains how to document the history, and the piece on what a surgical quote covers applies to whatever is billed privately.

Finally, the team. The American Cleft Palate-Craniofacial Association publishes standards for craniofacial teams, and adults are entitled to return to one. A craniofacial or reconstructive plastic surgeon, an orthodontist, an oral and maxillofacial surgeon, an ENT, and an anesthesiologist who has seen the airway can plan the whole sequence. A second consultation with such a team is often more useful than a fourth opinion from a cosmetic office, and the piece on board certifications explains what to check.

The honest summary

Hemifacial microsomia does not end at eighteen. Childhood surgery is designed to support growth, function, and hearing, and much of it is expected to relapse partly or to need a definitive adult stage. An adult who still sees a tilted smile, a short jaw on one side, a flat cheek, or an unconvincing ear is not asking for vanity surgery. They are asking for the last stage of a plan that was never finished.

What matters most is the order. The bite decides whether the skeleton has to move. The skeleton decides how much soft tissue is missing. Fat grafting, implants, and filler come after the bone is where it belongs, and the ear plan has to be coordinated with the hearing plan. Throughout, the airway, the neck, and the operative history decide what anesthesia is safe.

A practice that answers a call about hemifacial microsomia by booking a filler appointment has misread the problem. The right one will ask to see the patient's teeth, the CT, and the old operative notes before it offers a single syringe.