[Paper Review] Cheekbone and Square Jaw Surgery in Asian Faces

Hello, I’m Dr. Jo Hyun-woo, director of 입체성형외과.

Today is the second paper review.

Actually, plastic surgeons interact quite actively with one another, but we do not have as much exchange with oral and maxillofacial surgeons.

Last year, I came across an article written in oral and maxillofacial surgery about cheekbone surgery and square jaw surgery, so I’d like to review it.

This paper was published in the fairly prestigious journal Oral Maxillofacial Surg Clin N Am 35 (2023) 83–96.

It was written based on cheekbone and square jaw surgery in Asians with wide faces.

In general, a face that looks wide at the jaw is said to mean a face with a gonial angle smaller than 120 degrees or a mandibular plane angle smaller than 20 degrees.

In the figure above, you can see that after surgery the square jaw angle changed to 127 degrees, and the mandibular plane angle changed to 15.2 degrees.

Next is an explanation of the most prominent part of the cheekbone.

The authors describe it in two ways. In short, they say that the most prominent part of the cheekbone is located on the outer side of the intersection point of lines 1) and 2) (MP), and that this may not match the actual most prominent point of the cheekbone.

The table above explains various methods of cheekbone surgery.

As I explained before in my article on the history of cheekbone surgery, there are many different methods for cheekbone surgery, and I explained the corresponding surgical techniques.

This also discusses various methods of cheekbone osteotomy, such as I-shaped and L-shaped approaches, incision methods, and fixation methods.

A is a method of pushing the cheekbone inward through an I-shaped osteotomy, and B is a method of pushing the cheekbone inward through an L-shaped osteotomy.

In my case, the 230-degree three-dimensional cheekbone surgery would correspond to method A, and 3D cheekbone surgery could correspond to method B.

This table shows various complications of cheekbone surgery and the corresponding solutions.

If nonunion occurs, it says to fix it again, and if palatal dysfunction or temporomandibular joint dysfunction occurs, it says to do exercises or take medication.

It also says that if cheek sagging occurs, revision surgery or a lift can be considered, and that for other nerve injuries or other issues, no special treatment is needed. In fact, it does not seem much different from what is discussed in plastic surgery.

Next is the section on square jaw surgery.

This is a table on the various methods, indications, and effects of square jaw surgery.

In fact, this is also very similar to what I always explain.

In case A, only the angle of the jaw near the ear is shaved. It can be helpful for patients whose angle area alone is especially prominent, right?

B is what we commonly call long-curve resection. Because it is cut long toward the front, the possibility of forming a secondary angle is low, and it is said to reduce the width of the square jaw a bit more.

C is contouring by rotating and shaving the bone. It is a surgery that cuts long all the way to the chin.

It is explained that this can increase the effect from the front and can raise the square jaw angle slightly higher.

D is what we commonly know as cortical osteotomy.

It says that cortical osteotomy alone is performed when the square jaw angle is normal but the width is broad, but in my case, I always perform cortical osteotomy together when doing square jaw surgery.

The cortex can be shaved or osteotomized, and I explained the advantages and disadvantages of each in a previous column.

As I always say, this table emphasizes that in square jaw surgery, it is important to accurately identify the location where the inferior alveolar nerve runs and to perform surgery safely.

This is the guide plate that also appeared in the previous paper review.

It says that if you cut the bone using this kind of guide, you can cut it into a more refined and attractive shape while preventing nerve damage more precisely.

It seems to be a method often used in dentistry as well.

Myself included, each director has his or her own skill, so I think that depending on the technique, it is possible to cut the bone well and achieve the desired shape even without using a guide.

These are complications that can occur after square jaw surgery.

Lower lip numbness, severe postoperative swelling, bleeding, infection, and secondary angles are complications that readers of my columns will already know well.

The authors’ final point is injury to the inferior alveolar nerve due to excessive resection.

I agree with this as well. If you cut too aggressively, there is a risk of nerve damage, so you definitely need to examine the CT carefully in advance and observe it well before surgery.

No matter how much the result improves aesthetically, if nerve damage occurs, the outcome can be very poor.

It says that if surgery is performed using a 3D printer guide, such serious results can be prevented.

Of course, I am careful as well, but I think having such a guide could make surgery a little more reassuring.

I have once again gone through a rather lengthy paper review.

I started this review because I was curious about how oral and maxillofacial surgeons approach facial contouring surgery, and after reading to the end, it does not seem very different from how our plastic surgery directors approach it.

The difference I personally think of is that in plastic surgery, we can also smoothly perform soft-tissue procedures such as liposuction, fat grafting, and lifting, so I think it may lead to better results.

Thank you for reading this long post.