Can a Prognathic Chin Be Improved with Chin Surgery Without Double Jaw Surgery?

A prognathic chin refers to a chin that is long and protrudes forward, making the lower jaw look like a shovel. When someone has a prognathic chin, the face may appear longer and give a stronger impression, so many people consider improvement. Most people think that double jaw surgery is absolutely necessary to correct a prognathic chin, but depending on the case, improvement may also be possible with chin surgery, which is a contouring procedure. Here, we will explain how chin surgery can help relieve a prognathic chin.

If the bite is normal but the chin protrudes, correction may be possible with chin surgery

A normal bite means that the upper teeth slightly cover the lower teeth. Even when there is no major problem with the bite, there are cases where the chin protrudes forward and appears like a prognathic chin. This is called chin hypertrophy, and by adjusting the length and position of the chin through chin surgery, it is possible to improve the face into a more balanced shape.

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

This person had a normal bite but had chin hypertrophy, with the chin being long and shifted to the left, and the asymmetry of the chin was clearly visible from the front. The center of the chin was偏 toward the left, but through chin surgery, the chin was moved to the right, allowing the center to be aligned in a more balanced position. In this way, even without double jaw surgery, asymmetry of the chin can be improved, and a long, protruding chin can also be refined more harmoniously through reduction and angle adjustment.

In cases of mild malocclusion, chin surgery can produce improvement comparable to double jaw surgery

Even in cases of prognathic chin with malocclusion, double jaw surgery is not always necessary. If the degree of malocclusion is not severe, it is possible to improve the prognathic chin by combining orthodontic treatment with chin surgery. The method involves moving the dental arch by about 5 mm through orthodontic treatment, and then adjusting the position of the protruding chin through chin surgery.

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

TS Plastic Surgery - Chin surgery + chin muscle lifting procedure

Through the pre- and post-operative 3D-CT images, you can see that this person underwent chin surgery during orthodontic treatment. After the dental arch was aligned to some extent, the protruding chin was moved backward, improving the forward projection of the chin. It is currently one month after surgery, so swelling remains, and once orthodontic treatment is also completed, more noticeable changes are expected compared with before the correction.

There are cases where chin surgery is needed even if double jaw surgery is performed

In cases of severe malocclusion accompanied by a prognathic chin, double jaw surgery is used to move the upper and lower jaws to correct the bite. If there is difficulty with chewing function, double jaw surgery is recommended for functional improvement.

However, double jaw surgery alone does not make the chin line look more refined. Double jaw surgery is an operation that moves the dental arch structure of the upper and lower jaws, and changes to the outer facial contour or the shape of the chin bone must be made separately.

Therefore, if you want a slimmer jawline, you may consider combining double jaw surgery with chin surgery.

Source: TS Plastic Surgery website

Incision site for double jaw surgery vs. osteotomy site for contouring surgery (square jaw, chin)

• Double jaw surgery: Improves the dental arch structure by moving the position of the upper and lower jaws.

• Contouring surgery (square jaw, chin surgery): Improves the facial shape by refining the bone contour of the outer face.

​ Even if the bite is improved with double jaw surgery, the outer contour such as the chin or square jaw must be refined separately. Therefore, when planning surgery, it is necessary to distinguish between double jaw surgery and contouring surgery.

Do I need double jaw surgery? Or can chin surgery be enough?

Unless the malocclusion is severe enough to require double jaw surgery, as explained above, there are cases where a prognathic chin can be improved with chin surgery alone.

Double jaw surgery requires caution during the operation because the main nerve lines and blood vessels are close to the osteotomy site, but chin surgery is performed while protecting the nerve lines distributed along the edge of the chin and the facial blood vessels that pass through the square jaw area, so it is a procedure with a relatively lower risk of nerve damage or bleeding.

In addition, chin surgery takes about 30 minutes, so the surgery time is shorter than that of double jaw surgery, and although recovery varies by person, it is generally expected that there will be no major inconvenience in daily life after about one week. On the other hand, double jaw surgery is an operation that adjusts the skeletal structure of the upper and lower jaws, and when the orthodontic treatment period is included, the treatment period is about two years, which often feels burdensome.

Chin surgery can help not only improve the shape of the chin, but also correct its position and improve asymmetry. It can also be applied not only to a prognathic chin, but also to a weak chin, a short chin, or a long and wide chin. Therefore, it can be an alternative when double jaw surgery feels burdensome.

However, before consulting, rather than hastily concluding, “I have a prognathic chin, so I must need double jaw surgery,” it is important to accurately understand your current condition through examinations such as 3D-CT and to consult thoroughly with a specialist to determine the direction and method of improvement.

※ Depending on the individual, side effects such as inflammation, bleeding, and nerve damage may occur, so sufficient consultation with the medical staff before surgery is necessary.

This is an example image to help with understanding.