Underbite Treatment in Seoul: Class III Orthodontics in English
Quick answer
An underbite is when the lower front teeth sit in front of the upper front teeth, clinically called anterior crossbite or Class III malocclusion. It may be dental or due to jaw size and position. At Isu Yonsei Baro Orthodontics, Dr. Sally Chaekyung Lee uses CBCT and 3D facial scanning to distinguish these, then discusses braces, aligners, growth treatment or surgical orthodontics.
What an underbite is
In a normal bite, the upper front teeth close slightly in front of the lower ones. In an underbite they close behind, so the lower incisors lead. Clinicians call this a Class III relationship or reverse overjet. Some people only have one or two front teeth in reverse; others have the whole lower jaw ahead, which can make the chin look prominent.
Common causes
- An upper jaw that is underdeveloped or set back
- A lower jaw that is large or has grown forward, often a family trait
- Teeth tipped in the wrong direction while the jaws are normal
- A functional shift, where the jaw slides forward to avoid a tooth contact
Why it matters
An underbite can wear the edges of front teeth, stress the gums of lower incisors and make biting into foods harder. Some people are self-conscious about the chin or lower face. In children, a functional shift left untreated may influence how the jaws grow, which is why early checks are recommended.
How it is diagnosed
The central question is how much of the problem is skeletal. A RAY Quantum 5D CT (CBCT) scan shows the size and position of both jaws, the thickness of bone around the lower incisors and any asymmetry. The RAY Face 3D facial scanner records the soft-tissue profile and chin position. Intraoral digital scans capture the bite in detail. For children and teens, a skeletal maturity analysis helps estimate remaining growth, since lower jaw growth can continue into the late teens.
Treatment options
- Children: early orthodontics may use upper-jaw expansion or protraction appliances to support upper jaw development.
- Teens and adults with a mild skeletal pattern: camouflage treatment with braces, ceramic braces or aligners, sometimes using temporary anchorage devices to move lower teeth back.
- Severe skeletal underbite: orthodontics combined with jaw surgery, usually after growth has finished.
Typical timeline
Early treatment in children is often a shorter first phase of about 6–12 months, with monitoring afterward. Camouflage treatment in adults commonly takes roughly 18–30 months. Surgical plans involve orthodontics before and after surgery and generally take longer. Individual results and side effects vary; treatment is decided after examination.
What to expect at Isu Yonsei Baro
The first visit takes about 60 minutes and includes digital scans, X-rays or CT and photos. Dr. Lee explains in English whether your underbite looks dental, skeletal or mixed, and what each path would realistically achieve. In Dr. Lee's practice, growth is monitored carefully in teenage Class III patients before committing to a final plan, because late jaw growth can change the picture. You receive a written estimate before deciding. If you may relocate during treatment, the clinic can prepare complete English records and plan appointments around your travel dates so an orthodontist abroad can continue your care.
At a glance
- Clinical terms: Class III malocclusion, anterior crossbite, reverse overjet
- Early evaluation in children is helpful because upper-jaw growth can sometimes be guided
- Mild adult cases are often treated with braces or aligners; severe skeletal cases may need surgery
- Lower jaw growth can continue into the late teens, which affects timing
- Dr. Lee has award-recognized research on Class III facial asymmetry
Your orthodontist
Dr. Sally Chaekyung Lee, DDS, PhD
- MOHW-certified orthodontic specialist
- PhD in Orthodontics, Yonsei University; Severance Hospital residency
- Member, Edward H. Angle Society of Orthodontists
- 2026 AJO-DO peer reviewer
- Consults in fluent English and treats you herself, start to finish
Isu Station Exit 2 · 1-minute walk
Mon & Thu until 9 PM · Sat 9 AM–2 PM
+82 2-592-2080
Frequently asked questions
Can an underbite be fixed without jaw surgery?
Many mild to moderate underbites can be improved with braces or aligners, sometimes with temporary anchorage devices, by adjusting tooth positions to compensate for the jaws. Children may benefit from appliances that guide upper jaw growth. Severe skeletal cases often need surgery for a stable bite and profile change. Imaging helps clarify which applies.
At what age should a child's underbite be checked?
Earlier is usually better for underbites. An evaluation around ages 6–8 allows the orthodontist to look for a functional shift or upper jaw deficiency, which may respond to early appliances. Not every child needs treatment immediately, and growth is often monitored into the teens.
Will my underbite come back after braces?
Because the lower jaw can keep growing into the late teens or beyond, Class III patterns can partly return in some people. That is why timing, careful growth assessment and retainers matter. If significant growth occurs, further treatment may be discussed. Results vary between individuals.
Can Invisalign treat an underbite?
Clear aligners can correct some mild underbites, particularly when front teeth are tipped rather than the jaws being far apart. Elastics and attachments are usually needed. More pronounced skeletal underbites tend to need braces, anchorage devices or surgery. Dr. Lee advises on suitability after reviewing your CBCT and scans.
Related reading
This page is general information, not a diagnosis. Individual results and side effects vary; treatment is decided after an in-person examination. See our editorial and medical review policy .
Talk to Dr. Lee in English
Send your concern and preferred dates. You'll get an examination, your options, a timeline and a written estimate before you decide anything.