What This Guide Covers
This guide explains what Class III malocclusion is, how it is diagnosed, and which treatments work best at different ages.
In a normal bite, the upper front teeth overlap the lower front teeth slightly. In Class III malocclusion, the opposite happens. The lower teeth sit in front of the upper teeth. Dentists call this an underbite. The condition may involve the teeth alone, the jawbones alone, or a combination of both. [7]
Understanding the type of Class III malocclusion you or your child has is the first step toward choosing the right treatment. A dental underbite (where the teeth are tilted in the wrong direction but the jaws are properly sized) is treated differently than a skeletal underbite (where the lower jaw is too large, the upper jaw is too small, or both). [4]
This guide is for adults with an underbite, parents of children with early signs of jaw misalignment, and anyone considering orthodontic treatment for a Class III bite. You will learn about timing, treatment options, surgery, costs, and when to see a specialist.
Understanding Class III Malocclusion
Class III malocclusion is a misalignment where the lower jaw, teeth, or both are positioned too far forward relative to the upper jaw.
Dental vs. Skeletal Underbite
A dental Class III malocclusion means the jawbones are roughly the right size, but the teeth are tilted or positioned incorrectly. The lower front teeth lean forward, or the upper front teeth lean backward. This creates the appearance of an underbite even though the jaw structure is close to normal.
A skeletal Class III malocclusion involves the bones themselves. The lower jaw (mandible) may be too large, the upper jaw (maxilla) may be too small, or both problems may exist at the same time. Skeletal cases tend to be more severe and are harder to treat with braces alone. [2]
Many patients have a combination of dental and skeletal issues. An orthodontist uses X-rays called cephalometric radiographs (side-view skull images) to measure the jaw angles and positions precisely. These measurements help determine how much of the problem is dental and how much is skeletal. [4]
What Causes an Underbite
Genetics is the leading factor. If a parent or grandparent has a prominent lower jaw or small upper jaw, the trait often appears in the next generation. [7]
Certain childhood habits can make a mild underbite worse. Prolonged thumb sucking, tongue thrusting (pushing the tongue against the lower teeth), and mouth breathing can influence how the jaws develop. Some medical conditions, such as cleft lip and palate, also increase the risk of underdeveloped upper jaws. [1]
Environmental factors rarely cause a Class III malocclusion on their own. They typically worsen an existing genetic tendency.
What Happens If an Underbite Is Not Treated
Leaving a Class III malocclusion untreated can lead to several functional and health problems over time. [7]
The misaligned bite places uneven forces on the teeth. This often causes premature wear on the biting edges of the front teeth and can chip or fracture enamel. Chewing efficiency drops because the teeth do not meet properly. Some patients develop temporomandibular joint (TMJ) pain, which is soreness or clicking in the jaw joints near the ears. Speech sounds that require the upper and lower teeth to meet, such as "s" and "th," may also be affected. [4]
Beyond function, a noticeable underbite can affect self-confidence. A concave facial profile (where the midface appears sunken) is a common cosmetic concern in skeletal Class III cases. [2]
Treatment Options by Age and Severity
The best treatment depends on the patient's age, growth status, and whether the underbite is dental, skeletal, or both.
Early Intervention for Growing Children (Ages 7 to 10)
The American Association of Orthodontists recommends a first orthodontic evaluation by age 7. [6] At this age, children still have a mix of baby teeth and permanent teeth, and their jawbones are actively growing. This creates a window where growth can be redirected.
A palatal expander is a device cemented to the upper back teeth. It gradually widens the upper jaw over several weeks. A wider upper jaw provides more room for the upper teeth and can improve the way the jaws fit together.
Reverse-pull headgear, also called a face mask, is often used alongside an expander. The mask hooks to the upper jaw with elastics and gently pulls the upper jaw forward while the child sleeps. Research on bone-anchored maxillary protraction in children, including those with cleft lip and palate, has shown that these devices can produce meaningful forward movement of the upper jaw. [1]
Early treatment does not always eliminate the need for braces or surgery later. However, it can simplify future treatment by reducing the severity of the jaw mismatch while the bones are still responsive to guidance. [6]
Treatment During Adolescence (Ages 11 to 17)
During the teenage years, growth is still occurring but slowing. Braces are the most common tool at this stage. An orthodontist can use Class III elastics (small rubber bands that stretch from the lower back teeth to the upper front teeth) to shift the bite forward.
If the skeletal discrepancy is moderate, functional appliances or headgear may still provide some benefit, especially if the adolescent has remaining growth. The orthodontist monitors growth using periodic X-rays and hand-wrist films to estimate how much growth is left.
Severe skeletal Class III cases in older teenagers are sometimes monitored until growth is complete, at which point orthognathic surgery (jaw surgery) becomes an option. Planning surgery before growth has finished risks relapse because the jaw may continue to grow in the wrong direction after the procedure.
Adult Treatment Options
In adults, the jawbones have stopped growing. This limits treatment to two main paths: orthodontic camouflage or surgical correction.
Orthodontic camouflage uses braces or clear aligners to move the teeth into the best possible alignment within the existing jaw positions. This approach works best when the skeletal discrepancy is mild. A 2018 case report published in the Journal of Orthodontics demonstrated stable long-term results in a patient with a mandibular asymmetry treated through camouflage orthodontics using sliding jig mechanics. [5] Corticotomy-assisted clear aligner treatment has also been described for accelerating tooth movement in certain complex cases. [3]
For moderate to severe skeletal Class III malocclusion in adults, orthognathic surgery combined with orthodontic treatment is typically the recommended approach. The surgery repositions the upper jaw, the lower jaw, or both. Braces are placed before surgery to align the teeth within each jaw, surgery moves the jaws into proper position, and braces after surgery fine-tune the final bite. [2]
Some adults with uncorrected skeletal discrepancies may seek esthetic procedures instead of orthognathic surgery. However, these procedures address appearance without correcting the underlying bite problem. A 2022 article in the American Journal of Orthodontics and Dentofacial Orthopedics noted the limitations of cosmetic camouflage for skeletal deformities, emphasizing that functional correction typically requires surgical intervention. [2]
What to Expect During Treatment
Treatment for Class III malocclusion follows a structured sequence that varies by the approach chosen.
Diagnosis and Treatment Planning
The process begins with a thorough evaluation. The orthodontist takes dental impressions or digital scans, photographs of the face and teeth, a panoramic X-ray, and a cephalometric X-ray. These records allow the orthodontist to measure jaw relationships, tooth positions, and facial proportions precisely. [4]
If surgery may be needed, the orthodontist refers the patient to an oral and maxillofacial surgeon for a joint consultation. Together, they develop a plan that addresses both the teeth and the jaws. Digital treatment planning software allows the surgical team to simulate the jaw movements before the actual procedure.
The planning phase typically takes one to two appointments over several weeks.
Non-Surgical Treatment Process
For dental Class III cases treated with braces or aligners, the orthodontist bonds brackets to the teeth or provides aligner trays. Class III elastics are usually worn for a portion of each day. These rubber bands apply a steady force that pushes the lower teeth back and pulls the upper teeth forward.
For children receiving a palatal expander, the device is cemented to the upper molars. A parent turns a small screw in the device once or twice daily, as directed by the orthodontist. Expansion typically takes three to six weeks. The expander then stays in place for several months to let new bone fill in the widened area. [6]
Appointments occur every four to eight weeks for adjustments. Non-surgical orthodontic treatment for Class III malocclusion typically lasts 18 to 30 months, though this varies by case complexity.
Surgical Treatment Process
Orthognathic surgery follows a three-phase approach. In the first phase, the orthodontist places braces and aligns the teeth within each jaw. This pre-surgical orthodontics phase typically lasts 12 to 18 months.
The surgery itself is performed under general anesthesia in a hospital or surgical center. The oral surgeon makes cuts in the jawbone, repositions the segments, and secures them with titanium plates and screws. Recovery typically involves a liquid or soft diet for several weeks, swelling that subsides over one to three months, and time off work or school for two to four weeks. [2]
After the jaws have healed, the orthodontist completes the final phase of treatment by fine-tuning the bite with braces. This post-surgical phase typically lasts six to twelve months. In total, the combined treatment often spans two to three years.
Cost Factors for Underbite Treatment
Costs for Class III malocclusion treatment vary widely based on treatment type, geographic location, provider, and case complexity.
Non-surgical orthodontic treatment with braces or aligners typically ranges from $3,000 to $8,000. This range reflects differences in treatment length, the type of appliances used, and regional pricing. Early interceptive treatment for children (expanders and limited braces) may cost $2,000 to $5,000 for the first phase alone.
Orthognathic surgery costs significantly more. The surgical procedure itself may range from $20,000 to $40,000 or more, depending on whether one jaw or both jaws are repositioned. This figure usually includes surgeon fees, anesthesia, and hospital charges but does not include the orthodontic treatment fees.
Many dental insurance plans cover a portion of orthodontic treatment, particularly for children. Medical insurance may cover orthognathic surgery if it is deemed medically necessary rather than purely cosmetic. Coverage criteria vary significantly between insurance carriers. Ask your orthodontist's office for a predetermination of benefits, which is a written estimate from your insurance company of what they will cover.
- Costs vary by location, provider, and case complexity. Always request a written treatment estimate.
- Non-surgical orthodontic treatment: typically $3,000 to $8,000.
- Interceptive treatment for children (Phase 1): typically $2,000 to $5,000.
- Orthognathic surgery (not including orthodontics): typically $20,000 to $40,000 or more.
- Medical insurance may cover jaw surgery when classified as medically necessary.
When to See a Specialist
Any sign of an underbite in a child or adult warrants evaluation by an orthodontist.
For children, the following signs suggest a Class III problem that should be assessed: the lower front teeth close in front of the upper front teeth, the lower jaw appears to stick out, difficulty biting into food with the front teeth, or a family history of underbite. The American Association of Orthodontists recommends screening by age 7, when the first permanent molars and incisors have typically come in. [6]
Adults who notice an underbite worsening over time, experience jaw pain or clicking, have difficulty chewing, or are concerned about facial profile changes should also seek an evaluation. A general dentist can identify a Class III malocclusion during a routine exam, but an orthodontist is the specialist trained to diagnose the type and severity and to plan treatment. Visit the orthodontics page to learn more about what orthodontists do.
If the orthodontist identifies a skeletal component, they will typically coordinate care with an oral and maxillofacial surgeon. This team approach ensures that both the teeth and the jaws are addressed together for the most stable outcome.
- Children should have an orthodontic evaluation by age 7 if an underbite is suspected. [6]
- Adults with jaw pain, difficulty chewing, or worsening bite alignment should request an orthodontic consultation.
- A general dentist can screen for Class III malocclusion, but an orthodontist provides the specialized diagnosis and treatment.
- Skeletal underbites typically require coordination between an orthodontist and an oral and maxillofacial surgeon.
Find an Orthodontist or Oral Surgeon Near You
Class III malocclusion treatment works best when guided by specialists who diagnose and treat bite and jaw problems every day. An orthodontist evaluates whether the underbite is dental, skeletal, or both, and builds a treatment plan around your specific anatomy and goals. If surgery is part of the plan, an oral and maxillofacial surgeon works alongside the orthodontist to reposition the jaws. Use our directory to find a qualified orthodontist or oral surgeon in your area and schedule a consultation.
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