Overview
This guide explains the surgical options for hemifacial microsomia, a congenital condition that causes one side of the face to develop less fully than the other. It is written for parents of affected children and for adults who were diagnosed earlier in life and are weighing further treatment.
Hemifacial microsomia (HFM) is the second most common congenital facial difference after cleft lip and palate.[1] It is also called craniofacial microsomia or, when eye and spine findings are present, Goldenhar syndrome.[1] The condition is present at birth but often becomes more visible as the face grows, because the affected side does not keep pace with the unaffected side.
Care is rarely a single operation. Most patients work with a craniofacial team across many years, with treatments timed to growth, dental development, and the severity of the asymmetry.[6]
What Hemifacial Microsomia Involves
Hemifacial microsomia is a spectrum, not a single diagnosis. Mild cases involve only slight jaw asymmetry, while severe cases affect the jawbone, jaw joint, ear, facial nerve, and soft tissue.[1] Roughly 10 to 15 percent of cases involve both sides of the face, though one side is usually more affected than the other.[1]
Structures That Can Be Affected
The condition stems from underdevelopment of tissues that come from the first and second pharyngeal arches during early fetal development.[1] The most commonly affected structures are the lower jaw (mandible), upper jaw (maxilla), external ear, middle ear, facial nerve, and the muscles and skin of the cheek.
- Mandible: shortened ramus, tilted occlusal plane, chin deviation toward the affected side
- Temporomandibular joint: small, malformed, or in severe cases absent
- Ear: ranges from mild shape difference to absent external ear (microtia or anotia) with hearing loss
- Facial nerve: weakness on the affected side that can affect smile and eye closure
- Soft tissue: thinner cheek and reduced fat and muscle volume
How Severity Is Classified
Surgeons commonly use the Pruzansky-Kaban classification to describe how much of the jaw and joint are affected. Type I is mild, with a small but normally shaped jaw. Type IIA has a more abnormally shaped jaw and joint that still functions. Type IIB has a joint that does not function normally. Type III means the jaw branch and joint are absent.[2]
This classification matters because it drives the treatment plan. A Type I jaw can often be corrected with a single later operation, while Type IIB and III usually need joint reconstruction at some point.[2][7]
What to Know About Treatment Timing
Treatment is staged across childhood and adolescence, with each stage timed to a specific developmental window. Surgeons aim to balance early correction against the risk of relapse as the face continues to grow.[3][7]
Infancy and Early Childhood (Birth to Age 6)
Care in this stage focuses on airway, feeding, and hearing. Severe HFM can crowd the airway and require positioning support, feeding therapy, or in some cases an early procedure to bring the lower jaw forward.[3] Hearing is checked early so that bone-conduction hearing devices can be fitted if needed.[1]
Most jaw surgery is delayed past this window unless the airway or feeding is at risk.
School Age (Ages 5 to 12)
This is when distraction osteogenesis is often considered for moderate to severe cases. Some research supports earlier intervention to improve facial symmetry before school years, while other evidence favors waiting until adolescence because of relapse risk. A 2014 systematic review of mandibular reconstruction in growing patients found that both approaches show outcomes that depend heavily on case selection and follow-up length, and no single timing strategy has been proven superior.[7]
Orthodontic care typically begins in this period to guide the eruption of permanent teeth and prepare the bite for any future jaw surgery.[3][4]
What to Expect From Each Surgical Option
Most patients undergo one or more of four main surgical approaches: distraction osteogenesis, costochondral rib grafting, orthognathic surgery, or soft tissue augmentation. The right combination depends on age, severity, and which tissues are most affected.[2][7]
Distraction Osteogenesis
Distraction osteogenesis gradually lengthens the jaw by cutting the bone and using a small device to slowly pull the segments apart. New bone forms in the gap as the device is turned a fraction of a millimeter each day, typically over two to four weeks.[3]
The device stays in place for another two to three months while the new bone hardens. Hospital stays for the placement surgery are usually one to three nights. Children often return to school within two weeks, though physical activity is restricted during the consolidation phase.[3]
Costochondral Rib Graft
When the jaw joint and ramus are missing or severely underdeveloped (Type IIB or III), surgeons may rebuild them using a graft taken from the patient's rib. The cartilage end of the rib acts as a new growth center for the jaw.[2]
The graft is typically placed in mid-childhood. Growth from the graft is unpredictable: it may grow too little, the right amount, or occasionally too much. The systematic review evidence shows that a substantial share of these patients need additional jaw surgery in the teen years to fine-tune the result.[7]
Orthognathic Jaw Surgery
Orthognathic surgery repositions the upper and lower jaws once growth is complete. For HFM, this often involves cutting and rotating the upper jaw to level the bite and advancing or rotating the lower jaw to center the chin. A separate chin procedure (genioplasty) may be added.[3]
Patients typically wear braces for 12 to 18 months before surgery and several months after. The hospital stay is usually one to two nights, with a soft diet for four to six weeks and a return to most activities within six to eight weeks.
Soft Tissue Procedures
Even after the bones are corrected, the affected cheek often looks thinner. Fat grafting (transferring fat from the abdomen or thigh) is the most common technique to restore volume. In severe cases, free tissue transfer using microsurgery can move skin, fat, and muscle from another part of the body to rebuild the cheek.[4]
Fat grafting is usually done as an outpatient procedure. Some of the transferred fat is reabsorbed, so multiple sessions are common to reach the desired result.[4]
Risks and Limits to Discuss With Your Surgeon
No surgical option fully reverses the underlying difference, and each carries trade-offs that should be discussed in detail before consent. Reported risks across the four main approaches include relapse with continued growth, partial loss of fat grafts, donor-site issues at the rib for costochondral grafts, temporary or permanent nerve weakness, infection, and the need for additional operations later.[5][7]
Outcomes also vary by surgeon experience and by how severe the starting asymmetry is. Families should ask any prospective surgeon about case volume, complication rates, and how revision surgery is handled.
Cost Factors and Insurance
Hemifacial microsomia treatment is typically classified as reconstructive, not cosmetic, which means most surgical care is covered by medical insurance rather than dental benefits.[5] Out-of-pocket costs depend on insurance plan, deductibles, hospital fees, and how many stages of treatment are needed.
Costs vary by location, provider, and case complexity. Without insurance, individual procedures often range as follows:
- Mandibular distraction osteogenesis: $30,000 to $80,000 per surgery, including device and hospital fees
- Costochondral rib graft reconstruction: $40,000 to $90,000
- Orthognathic jaw surgery: $25,000 to $60,000 per jaw
- Fat grafting: $5,000 to $15,000 per session
- Pre-surgical orthodontics: $5,000 to $10,000 over 12 to 24 months
Working With Insurance
Pre-authorization is almost always required. Surgeons' offices typically submit medical necessity documentation that includes diagnostic imaging, photographs, airway or sleep studies if relevant, and the surgeon's treatment plan.[5] Denials are common on first submission and are often reversed on appeal when medical necessity is clearly documented.
Some states classify craniofacial conditions as a special category and require coverage. Families should ask the surgical team about state mandates and craniofacial coverage rules in their plan, and can also request team-care advocacy through a care coordinator at an accredited cleft and craniofacial team.[6]
When to See a Specialist
Hemifacial microsomia is not managed by a general dentist. Care belongs with a craniofacial team led by an oral and maxillofacial surgeon or a craniofacial plastic surgeon, working alongside orthodontics, ENT, audiology, speech, and often genetics.[6]
Refer to a specialist when any of the following apply:
- A newborn shows visible asymmetry of the jaw, ear, or face
- A child has feeding difficulty, noisy breathing, or sleep-disordered breathing on the affected side
- Hearing loss is suspected or confirmed on one side
- The bite is shifting, the chin is deviating, or the upper jaw is tilting as the child grows
- An adolescent or adult is considering definitive jaw correction
- A previously treated patient is noticing relapse or new asymmetry
Who Belongs on the Team
A typical craniofacial team includes an oral and maxillofacial or craniofacial surgeon, an orthodontist with experience in surgical orthodontics, an ENT surgeon, an audiologist, a speech therapist, and a geneticist. A psychologist or social worker is often involved to support the child and family across years of treatment.[6] The American Cleft Palate-Craniofacial Association maintains a directory of accredited teams that meet defined standards of care.[6]
Find a Specialist Near You
Hemifacial microsomia treatment is a long-term partnership with a craniofacial team. Look for an oral and maxillofacial surgeon affiliated with a hospital-based craniofacial program, with documented experience in distraction osteogenesis and orthognathic surgery for HFM. Browse the oral-surgery page to find specialists in your area and review their training, hospital affiliations, and case experience.
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