Learn the differences between T osteotomy and ㅅ osteotomy in chin surgery. Discover which chin reduction technique is safer, more natural, and best suited to your facial structure at AB Plastic Surgery in Gangnam, Seoul.

Hello,
I am Dr. Jo Dong-Pil, Board-Certified Plastic Surgeon at AB Plastic Surgery in Gangnam, Seoul.

In modern chin surgery, achieving a balanced and natural facial contour depends greatly on the shape, length, and projection of the chin. A well-designed chin reduction surgery tailored to each patient’s anatomy can significantly improve overall facial harmony and proportions.

Among the many techniques used in genioplasty (chin surgery), the most critical factor is the osteotomy method. Today, I will explain two advanced and commonly used techniques in chin reduction surgery: T osteotomy and ㅅ osteotomy (Inverted-V-shaped osteotomy).

Q. What Is Chin Osteotomy in Chin Surgery?

An osteotomy refers to the surgical cutting of bone to reshape the chin.
In earlier years, chin surgery was often performed using burring (rotational bone shaving) alone. However, clinical experience has shown that burring has limitations depending on the patient’s mental nerve position, bone thickness, and chin shape.

As chin surgery techniques advanced, T osteotomy was developed to allow more precise and predictable chin reduction while maintaining safety around the nerve line.

 Q. What are T osteotomy and ㅅ osteotomy?

T osteotomy and ㅅ osteotomy are classified based on the shape of the bone cut below the nerve line.

• T Osteotomy

When the chin bone is cut in a straight horizontal line below the nerve line, it is called a T osteotomy. This method allows controlled reduction of chin length and width.

• ㅅ Osteotomy (Inverted-V-Shaped Osteotomy)

When the bone is cut in an ㅅ-shaped (inverted-V-like) pattern below the nerve line, it is referred to as a ㅅ osteotomy.
Technically, ㅅ osteotomy is a modified form of T osteotomy, designed to better accommodate certain nerve positions and chin anatomies.

Q. How Do Surgeons Choose Between T Osteotomy and ㅅ Osteotomy?

The most important factor when choosing an osteotomy technique in chin surgery is the position of the mental nerve.

• If the nerve line is relatively high, a standard T osteotomy can usually be performed safely.

• If the nerve line is low, performing a straight T osteotomy may increase the risk of nerve injury.

In such cases, surgeons often select ㅅ osteotomy, which allows the bone to be cut while avoiding direct contact with the nerve line.

Advantages of ㅅ Osteotomy

• Safer approach when the nerve line is low

• More effective for chin length reduction

• Less restriction from nerve position

• May create a more natural jawline when viewed from the side

Although refining the posterior jawline connection (secondary angle) can be more technically demanding with ㅅ osteotomy, it often results in a softer and more natural contour compared to T osteotomy.

Because both techniques have distinct advantages and limitations, selecting the appropriate osteotomy method based on individual anatomy is essential for optimal results.

Q. Which Technique Causes More Skin Sagging: T Osteotomy or ㅅ Osteotomy?

Patients often ask whether skin sagging differs between T osteotomy and ㅅ osteotomy.

For patients with a low nerve line whose primary goal is chin length shortening, ㅅ osteotomy may be more suitable.
If the nerve line is extremely low and both T osteotomy and ㅅ osteotomy are difficult, burring may sometimes be considered.

There is a common misconception that burring causes more skin sagging than osteotomy techniques. However, skin sagging after chin surgery depends on multiple factors, including:

• Whether chin length or width is reduced

• The degree of bone reduction

• Soft tissue attachment and healing response

For example, when T osteotomy significantly reduces chin length or width, sagging of the inner soft tissue attached to the bone may occur, potentially making a double chin appear more noticeable.

While skin dissection may influence postoperative appearance, there is currently no clear medical evidence proving that greater dissection alone directly causes more skin sagging.

Ultimately, choosing the most appropriate chin surgery technique for each patient helps minimize postoperative concerns and improves overall satisfaction.

Today, we discussed the key osteotomy techniques used in chin surgery, including T osteotomy and ㅅ osteotomy.

Because chin surgery plays a critical role in determining overall facial balance, selecting a customized surgical approach based on individual facial anatomy is essential.

At AB Plastic Surgery in Gangnam, experienced surgeons provide detailed consultations and perform advanced chin surgery techniques based on years of clinical expertise. Our goal is to achieve safe, natural, and satisfying results for every patient.

If you are considering chin reduction surgery or chin contouring, we invite you to schedule a consultation.

For further inquiries, please contact AB Plastic Surgery at +82-10-9674-1298 or reach out via WhatsApp using the same number to receive a detailed consultation.

Writer Dr. Dr. Jo Dong-Pil, AB Plastic Surgery