ADDITIVE AND REDUCTION MENTOPLASTY, WHEN IS IT NEEDED?

Mentoplasty is a surgical practice generally used to reshape the chin, both in chin augmentation and reduction, from an aesthetic point of view.

It is also performed in the following cases:

• chin deformities resulting from abnormalities in the development of the jawbone. Sometimes the jaws continue to grow on one side of the face but not on the other, resulting in facial asymmetry
• in some cases a part of the jaw is missing; this condition is known as congenital mandibular agenesis
• on a chin that is disproportionate to other facial features
• as part of gender reassignment surgery. The size and shape of the lower chin and jaw is slightly different in men and women. Some people choose to have mentoplasty as part of their gender transition
• as part of craniofacial reconstruction following trauma or cancer surgery
• as part of orthognathic surgery (orthognathic surgery involves repositioning facial bones in order to correct deformities that affect the patient's ability to speak or chew normally)

Although chin deformities are the most common facial abnormality, mentoplasty is not one of the most frequent procedures performed in plastic surgery. This is due to the invasiveness of the procedure, and the use of fillers is often preferred.

Mentoplasty is mainly performed in adult patients; it is not recommended in children until all adult teeth have grown and the jaw is close to its adult size.

As far as gender is concerned, women account for 69% of patients who choose mentoplasty, while only 31% are men.

Mentoplasty is divided into two main categories:

• chin augmentation
• chin reduction

Chin augmentation is performed by inserting an implant under the skin of the chin or by performing a "sliding" mentoplasty. The insertion of an implant takes 30–60 minutes, while a sliding implant takes more time, 45–90 minutes.
If the mentoplasty is done in conjunction with orthognathic surgery, the operation may take up to three hours.

There are fewer mentoplasty procedures available for patients with small chins. To increase the volume and insert the implant, the surgeon may choose to make the incision outside, under the chin or inside the mouth (intraoral).

In both cases, the surgeon cuts through several layers of tissue, taking care not to damage the important nerve in the chin. The surgeon makes a pocket in the connective tissue inside the chin and washes it with an antiseptic solution.
The sterile implant is then inserted into the pocket and positioned accordingly. The incision is closed and the wound covered with sterile strips.

A sliding mentoplasty can be performed if the patient's chin is too small or if the deformity is more complex. In this procedure, the surgeon cuts through the jaw with an oscillating saw and removes part of the bone, then moves the bone segment forward, holding it in place with metal plates and screws. After the bone segment is fixed in place, the incision is closed and the patient's head is wrapped with a pressure dressing.

Preparation

Patients should quit smoking and stop all drugs containing aspirin or NSAIDs for two weeks before menoplasty. If the surgeon plans to make an incision under chin, the patient should use an antibacterial facial cleanser for two days before surgery.

Patients awaiting an intraoral approach should rinse their mouth with mouthwash three times a day for two days before surgery. They should not eat or drink anything for eight hours before the procedure.

The post-therapy considerations are as follows:

• A soft or liquid diet for four to five days
• Sleep using 2–3 pillows
• Rinse the mouth with a solution of hydrogen peroxide and hot water two or three times a day
• Avoid exercise for about two weeks

Risks

In addition to infections, bleeding, allergic reaction to anaesthesia, the risks of implant placement are as follows:

• chin deformity following an infection
• major nerve injury in the chin, resulting in loss of sensitivity or paralysis of the chin muscles
• erosion of the bone under the implant
• displacement of the implant
• extrusion of the implant