[ARTICLE] Square Jaw Surgery: Facial Bone Structure and Lower-Face Balance Matter More Than the Amount of Bone Reduction

A square jaw may be a concern when the lower part of the face appears wide from the front or when the angle of the jawbone below the ear is prominent from the side. This facial shape can be influenced by various factors, including not only the size and shape of the mandible, but also the development of the masseter muscles used for chewing and the amount of fat beneath the chin.

Square jaw surgery is a type of facial contouring surgery that aims to improve the contour of the lower face by adjusting the shape and width of the mandible. However, the surgical outcome is not determined simply by removing a large amount of bone. It is important to determine the appropriate extent and location of bone reduction based on each individual’s skeletal structure and overall facial proportions. In particular, excessive reduction of the mandibular angle located below the ear may result in an unnatural side profile. On the other hand, reducing only the prominent area visible from the side may not create sufficient improvement in facial width when viewed from the front. Therefore, both the frontal and side contours should be evaluated when planning the surgery.

Depending on the patient’s skeletal structure, surgical techniques such as long-curved mandibular angle reduction or cortical bone reduction may be considered. Long-curved mandibular angle reduction involves reshaping the bone contour along a continuous line extending from the mandibular angle below the ear toward the chin. Cortical bone reduction involves removing a portion of the outer cortical layer of the mandible to help reduce the width of the lower face when viewed from the front. Before surgery, it is necessary to assess not only the shape and thickness of the bone but also the condition of the surrounding soft tissues. The width of the lower face can also be affected by factors such as the size of the masseter muscles and the thickness of the fat layer. Therefore, surgery targeting the bone alone may sometimes produce a different degree of change than initially expected.

For this reason, imaging examinations and a physical evaluation should be performed to assess the structure of the mandible as well as the condition of the masseter muscles and surrounding soft tissues. The appropriate surgical method and extent of correction should then be determined according to the individual cause. In some cases, treatment of soft tissues, such as the masseter muscles or fat, may also be considered together with bone surgery.

Dr. Kwon Soon Beom, Chief Director of ARC Plastic Surgery, explained, “The appearance of a square jaw is determined by multiple factors, including not only the mandible but also the masseter muscles and facial fat. Rather than simply increasing the amount of bone reduction, the surgical plan should be established after carefully evaluating the overall facial proportions and the structure of the lower face.”

He continued, “Major nerves and blood vessels are located around the areas treated during facial contouring surgery, so it is essential to thoroughly assess the anatomical structures before surgery. Patients should also receive a detailed explanation from their medical team regarding the surgical method, expected changes, possible complications such as bleeding or sensory changes, and the recovery process before making a decision.”

Source: Hemophilia Life (http://www.hemophilia.co.kr)