Genioplasty for Improving Facial Side Profile Contour

Depending on the position of the chin tip and the degree of mouth protrusion, the facial side profile may look awkward. In such cases, protrusion correction surgery or two-jaw surgery may be considered,

but genioplasty alone, which does not affect dental occlusion, can also be expected to produce significant improvement.

I will explain the criteria used to diagnose the ideal chin position and the advantages and disadvantages of various methods for improving the appearance of the chin.

Diagnosis

Before looking in detail at genioplasty for improving the facial side profile (profile), let me first explain the ideal facial side profile.

"Ricketts line" connecting the tip of the nose and the chin tip

There are various reference points that can be used to analyze and define the side profile, but the most commonly used standard is to look at the position of the lips based on the "line connecting the tip of the nose and the chin tip (Ricketts line)."

Using the Ricketts line as a reference, an ideal side profile is defined as one in which the upper lip is located about 4 mm inward and the lower lip about 2 mm inward. However, in East Asians, the mouth tends to protrude slightly, so I do not think a side profile in which the lips touch the Ricketts line looks awkward.

However, if the mouth protrudes somewhat excessively, or if the chin is significantly set back, the facial side profile may look awkward and may also create a somewhat sullen impression.

Looking more specifically at the shape of the chin bone,

Compared with Normal (the typical appearance of the chin),

When the chin bone volume is small (Microgenia),

When the chin volume is excessive (Macrogenia),

When the chin is long but set back (Long Retrogenia),

and similar conditions.

Improvement methods

1. Procedure - filler injections

To improve the position and lack of volume of the chin bone, a simple filler injection procedure can be considered as a way to increase the volume of the soft tissue.

Filler injection procedures are simple, and because you can return to daily life immediately after the procedure, they are actually preferred by many people.

However, in addition to the advantage of convenience, filler injections also have several disadvantages as follows.

Disadvantages

1. Safe fillers are not permanent, and after a certain period of time, almost all of them are absorbed.
2. The filler may cause erosion of the chin bone, resulting in part of the chin bone being worn away like a crater.
3. Even if non-absorbable filler is used, it cannot be removed cleanly if removal is desired, and it may cause the chin skin tissue to sag downward.
4. The chin volume is supplemented, but the double-chin line caused by the chin being set back is not improved.

In a case where chin filler injections were performed, the chin area has been eroded into a crater-like shape

2. Simple surgery - autologous fat grafting

This is a slightly more involved surgery than filler treatment, but it compensates for the drawbacks of filler injections and uses the patient's own tissue, which is one of the chin surgery methods I personally think very highly of.

3. Simple surgery - implant insertion

Chin implant insertion is a relatively simple procedure in which, under local anesthesia or sedation, an implant is inserted through a small incision inside the mouth and placed in front of the chin bone.

There are various types of implants used in the chin area,

and depending on the surgeon performing the operation, the preferred type of implant, the incision site, and whether the implant is fixed to the bone or not may differ.

Therefore, there can be many differences depending on the surgeon performing the operation.

Implant insertion is also a relatively simple surgery, so it is very common and widely performed.

However, while chin implant insertion has the advantage of being a simple procedure, it also has disadvantages.

Disadvantages

1. The chin bone in contact with the inserted implant undergoes partial erosion and becomes worn away.
2. If the implant is not fixed, the inserted implant may be pushed upward or shift out of position.
3. The chin volume is supplemented, but the double-chin line caused by the chin being set back is not improved.

As can be seen in the multiple CT scans below, erosion can be observed in the bone at the area where the chin bone and implant were in contact. In addition, it can be observed that the implant is not positioned in the chin area but has been pushed upward from the chin.

CT showing the chin bone that has been worn away where it contacted the implant

As can be seen in the CT below, one side of the implant has been pushed upward and tilted. During revision surgery, it was fixed in the correct position.

In the postoperative CT on the right, you can observe that the bone in the area previously in contact with the implant has been worn away.

4. Chin bone osteotomy and advancement

As a more fundamental method, this surgery involves cutting the patient's own chin bone horizontally or in a curve, then advancing it forward and fixing it in place.

Depending on the length of the chin, various methods are applied as shown below.

If the length is appropriate, the bone is cut horizontally and advanced as is,

if the length is long, a sandwich osteotomy is performed, the middle portion is removed, and the lowest chin bone segment is advanced upward and fixed,

if the length is short, bone cut from the surrounding area is grafted into the osteotomy gap to increase the length while advancing it.

If the chin length is appropriate - horizontal osteotomy followed by advancement as is

If the chin length is short - horizontal osteotomy followed by inserting bone cut from the surrounding area in between to lengthen it while advancing

If the chin length is long - sandwich osteotomy followed by removing the middle portion and advancing the lower chin bone upward to fix it

In this post, I briefly introduced the various methods of chin surgery for improving the facial side profile (profile).

More detailed explanations of each method will be provided in separate future posts.