Orthognathic surgery
Underbite Jaw Surgery — Correcting a Prominent Lower Jaw
Assessment and combined surgical and orthodontic treatment when the lower jaw sits too far forward and the bite is reversed.
Overview
Also known as: reverse bite, prominent lower jaw, mandibular prognathism, Class III bite
An underbite is a condition in which the lower jaw sits forward relative to the upper jaw, so the lower front teeth close in front of the upper ones — a so-called reverse bite. Sometimes the cause is excess growth of the lower jaw, sometimes underdevelopment of the upper jaw, and often a combination of both.
In marked cases in adults, when the mismatch lies in the bones themselves, orthodontic treatment alone may not be enough. Orthognathic surgery, which changes the position of one or both jaws, may then be discussed.
Treatment is usually planned together with an orthodontist and involves orthodontic preparation before surgery and finishing afterwards. Whether and how to treat is decided individually after examination and investigations.
When to seek a consultation
- The lower front teeth close in front of the upper teeth.
- A markedly prominent chin and lower jaw in profile.
- Difficulty biting or chewing related to the position of the jaws.
- An orthodontist has referred you for a surgical opinion because the mismatch is skeletal.
What treatment may involve
- Clinical examination, photographs, models or digital scans and imaging to analyse the jaws.
- Joint planning with an orthodontist, usually with orthodontic preparation before surgery.
- Surgery under general anaesthesia, in which the position of the lower and/or upper jaw is changed and the bones are fixed in the new position.
- Orthodontic finishing and regular follow-up after surgery.
What to bring to the consultation
- An identity document and, where applicable, a referral from your GP or specialist.
- Existing medical records: discharge summaries, outpatient notes and test results.
- Imaging studies (X-rays, CT, MRI) on a disc or other digital medium, together with the written reports.
- A list of your current medicines, known allergies and chronic conditions.
- Information from your orthodontist, if you have one — treatment plan, photographs, models.
Recovery and follow-up
After surgery, swelling, discomfort and limited mouth opening are expected in the first days. A soft or liquid diet is usually advised for a period, together with careful oral hygiene.
How long recovery takes is individual and depends on the extent of surgery and on healing. Follow-up includes check-ups and continued orthodontic treatment.
Risks and alternatives
Besides general surgical risks (related to anaesthesia, bleeding, infection), possible risks include numbness of the lower lip and chin, bite changes that need further correction, discomfort in the jaw joints and the need for a further procedure.
Alternatives depend on severity: in milder cases orthodontic treatment alone, with a compromise result, may be discussed, and some patients choose not to have surgery. The options are discussed openly at consultation.
Every surgical procedure carries general risks — for example those related to anaesthesia, bleeding, infection, delayed healing or scarring. The specific risks depend on your health, and on the type and extent of the procedure.
Possible alternatives — including observation, non-surgical treatment or referral to another specialist — are discussed openly during the consultation.
Outcomes and recovery time vary between individuals and cannot be guaranteed in advance.
Frequently asked questions
Can an underbite be corrected without surgery?
In milder cases, or while growth is still ongoing, orthodontic treatment alone is sometimes possible. For a marked skeletal mismatch in adults, a combination with surgery is usually discussed — this is assessed after examination.
How long is recovery after underbite surgery?
Recovery is individual. Swelling and eating restrictions are most noticeable in the first days, and overall treatment continues with orthodontic finishing.
Will there be visible scars after the operation?
Jaw operations are in most cases performed through the mouth, but the approach depends on the specific plan and is discussed at consultation.
How much does underbite surgery cost?
The cost depends on the type and extent of treatment and is discussed after consultation and an individual plan.
This information does not replace a medical examination. Whether treatment is suitable for you is assessed individually after a consultation.