Mentoplasty

Definition
Purpose
Demographics
Description
Diagnosis/Preparation
Aftercare
Risks
Normal results
Morbidity and mortality rates
Alternatives

Definition

Mentoplasty is a term that refers to plastic surgery procedures for the chin. It comes from the Latin word mentum, which means chin, and the Greek verb plassein, which means “to form” or “to shape.” Mentoplasty is also known as genioplasty or chinplasty.

Purpose

Mentoplasty may be done for several reasons:

• To correct malformations of the chin resulting from developmental abnormalities of the bones in the jaw. Sometimes the jawbones continue to grow on one side of the face but not the other, leading to facial asymmetry. In other instances a part of the jawbone is missing; this condition is known as congenital agenesis of the jaw.
• To reshape a chin that is out of proportion to other facial features.
• As part of gender reassignment surgery. The size and shape of the chin and lower jawline are somewhat 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 the facial bones in order to correct deformities that affect the patient’s ability to speak or chew normally.

KEY TERMS

Aesthetic— Pertaining to beauty. Plastic surgery done to improve the patient’s appearance is sometimes called aesthetic surgery.

Agenesis— The absence of an organ or body part due to developmental failure.

Alloplast— An implant made of an inert foreign material such as silicone or hydroxyapatite.

Congenital— Present at the time of birth.

Extrusion— Pushing out or expulsion. Extrusion of a chin implant is one possible complication of mentoplasty.

Genioplasty— Another word for mentoplasty. It comes from the Greek word for “chin.”

Hematoma— A localized collection of blood in an organ or tissue due to broken blood vessels.

Intraoral— Inside the mouth.

Malocclusion— Malpositioning and defective contact between opposing teeth in the upper and lower jaws.

Microgenia— An extremely small chin. It is the most common deformity of the chin.

Orthognathic surgery— Surgery that corrects deformities or malpositioning of the bones in the jaw. The term comes from two Greek words meaning straight and jaw.

Sliding genioplasty— A complex plastic surgery procedure in which the patient’s jawbone is cut, moved forward or backward, and repositioned with metal plates and screws.

Submental— Underneath the chin.

Insurance coverage for mentoplasty depends on its purpose. Chin reshaping that is done to improve personal appearance is not usually covered by insurance. Mentoplasty that is performed as a reconstructive procedure after trauma, genetic deformity, or orthognathic surgery may be covered by insurance.

The cost of mentoplasty varies considerably according to the complexity of the procedure. The average surgeon’s fee for a chin implant was $1,612 in 2002. The average fee for a sliding genioplasty, however, was $4,000–$6,000.

Demographics

In spite of the fact that chin deformities are the most common facial abnormality, mentoplasty is not one of the more frequently performed procedures in plastic surgery. In 2002, there were 18,352 mentoplasties performed in the United States, compared to117,831 face lifts and 282,876 liposuctions. Most mentoplasties are done in combination with rhinoplasties.

Mentoplasty is primarily performed in adult patients; it is not usually done in children until all permanent teeth have come in and the jaw is close to its adult size. According to the American Society of Plastic Surgeons, 7% of patients who had mentoplasties in the United States in 2002 were 18 or younger; 35% were between the ages of 19 and 34; 40% were between the ages of 35 and 50, while another 15% were between 51 and 64. Only 3% were over 65.

With respect to sex, women account for 69% of mentoplasty patients; only 31% are men.

Description

Mentoplasties fall into two large categories: procedures that augment (increase) small or receding chins; and those that reduce large or protruding chins. Chin augmentation is done more frequently than chin reduction, reflecting the fact that microgenia (small chin) is the most common abnormality of the chin.

Chin augmentation

Chin augmentation can be performed by inserting an implant under the skin of the chin or by performing a sliding genioplasty. Insertion of an implant takes 30–60 minutes, while a sliding genioplasty takes slightly longer, 45-90 minutes. If the mentoplasty is done together with orthognathic surgery, the operation may take as long as three hours.

Chin implants are used in patients with mild or moderate microgenia. At one time they were made of cartilage taken from donors or from other sites on the patient’s body, but as of 2003 alloplastic implants (made from inert foreign materials) are used more often because they reduce the risk of infection. To insert the implant, the surgeon can choose to make the incision under the chin (submental) or inside the mouth (intraoral). In either case, the surgeon cuts through several layers of tissue, taking care to avoid damaging the major nerve in the chin. The surgeon makes a pocket in the connective tissue inside the chin and washes it out with an antiseptic solution. The sterile implant is then inserted in the pocket and positioned properly. The incision is closed and the wound covered with Steri-Strips.

A sliding genioplasty may be performed if the patient’s chin is too small for augmentation with an implant, or if the deformity is more complex. In this procedure, the surgeon cuts through the jawbone with an oscillating saw and removes part of the bone. He or she then moves the bone segment forward, holding it in place with metal plates and screws. After the bone segment has been fixed in place, the incision is closed and the patient’s head is wrapped with a pressure dressing.

Chin reduction

Reduction of an overly large or protruding chin may be done either by direct reduction or a sliding genioplasty. In a direct reduction, the surgeon makes either a submental or an intraoral incision and removes excess bone from the chin with a burr. A sliding genioplasty reduction is similar to a genioplasty to augment the chin, except that the bone segment is moved backward rather than forward.

Diagnosis/Preparation

Diagnosis

Diagnostic evaluation consists of a facial analysis as well as a complete dental and medical history. The chin is one of the three most significant parts of the face from an aesthetic standpoint, the others being the forehead and the nose. Many patients who are concerned about the size of their nose, for example, can be helped by having a too-small chin augmented as well as having the nose reshaped. In the facial analysis, the face is divided into thirds, with the mouth and chin in the lowest third. The surgeon compares the proportions of the features in each third in order to determine the most suitable procedure for restoring balance. The patient will be photographed from several angles to document the condition of the chin before surgery.

The dental history and x-ray studies of the head and jaw are necessary in order to determine whether the facial disproportion can be corrected by an implant or simple reduction, or whether orthognathic surgery is required. Patients who have severe maloclusion (irregular contact between the teeth in the upper and lower jaws) or deformities of the facial bones are usually referred to a maxillofacial specialist for reconstructive surgery .

Lastly, the surgeon will evaluate the patient for any signs of psychological instability, including unrealistic expectations of the results of surgery.

Preparation

Patients should stop smoking and discontinue all medications containing aspirin or NSAIDs for two weeks prior to mentoplasty. If the surgeon is planning to make a submental incision, the patient should use an antibacterial facial cleanser for two days before surgery. Patients scheduled for an intraoral approach should rinse the mouth with mouthwash three times a day for two days before surgery. They should not eat or drink anything for eight hours prior to the procedure.

Aftercare

Patients should have someone drive them home after the procedure. They are given medication for discomfort and a one-week course of antibiotic medication to reduce the risk of infection. Most patients can return to work in seven to 10 days.

Other aspects of aftercare include the following:

• a soft or liquid diet for four to five days
• raising the head of the bed or using two to three pillows
• rinsing the mouth with a solution of hydrogen peroxide and warm water two to three times daily
• avoiding sleeping on the face and unnecessary touching of the chin area
• avoiding vigorous physical exercise for about two weeks

Risks

In addition to infection, bleeding, and an allergic reaction to the anesthetic, the risks of insertion of a chin implant include:

• deformity of the chin following an infection
• injury to the major nerve in the chin, leading to loss of feeling or paralysis of the chin muscles
• erosion of the bone beneath the implant
• moving around or dislocation of the implant
• extrusion (pushing out) of the implant

Specific risks associated with sliding genioplasties include:

• under- or overcorrection of the defect
• injury to the major nerve in the chin
• failure of the bone segment to reunite properly with the other parts of the jaw
• damage to the roots of the teeth
• hematoma (a collection of blood within a body organ or tissue caused by leakage from broken blood vessels; it can damage the results of a mentoplasty by causing pressure that distorts the final shape of the chin)

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

Mentoplasties may be performed by plastic surgeons, oral surgeons, or maxillofacial surgeons. Fat injections and facial liposuction are usually performed by plastic surgeons.

Chin implant insertions or direct reductions are usually performed as outpatient procedures in the surgeon’s office or an ambulatory surgery center. The patient may be given either general or local anesthesia. Sliding genioplasties can be done as outpatient procedures; however, they are usually performed in hospitals under general anesthesia, particularly if the patient is having orthognathic surgery at the same time.

Normal results

Normal results of either augmentation or reduction mentoplasty include correction of facial asymmetry and disproportion. The functioning of the jaw is also often improved. Patients who have had a mentoplasty are usually very satisfied with the results.

Morbidity and mortality rates

The rate of complications with chin implants as well as sliding genioplasties is about 5%.

Alternatives

Fat injections

In some cases, fat may be injected into the area below the chin to plump up the skin and minimize the apparent size of the chin. This technique, however, is limited to minor disproportions of chin size. In addition, fat injections must be repeated periodically as the fat is gradually absorbed by the body.

Liposuction

Facial liposuction can be used together with or instead of mentoplasty to improve the patient’s profile. In particular, removal of fatty tissue below the chin can make a receding chin look larger or more prominent.

QUESTIONS TO ASK THE DOCTOR

• Would you recommend a chin implant or a sliding genioplasty in my case?
• Would you use a submental or an intraoral approach to a chin augmentation?
• How many mentoplasties have you performed?
• Should I consider a mentoplasty in combination with another facial procedure?

Resources

BOOKS

Sargent, Larry, MD. The Craniofacial Surgery Book. Chattanooga, TN: Erlanger Health System, 2000.

“Temporomandibular Disorders.” In The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

PERIODICALS

Abraham, Manoj T., MD, and Thomas Romo III, MD. “Liposuction of the Face and Neck.” eMedicine, January 8, 2003 [cited April 22, 2003]. http://www.emedicine.com/ent/topic581.htm.

Chang, Edward, MD, DDS, Samuel M. Lam, MD, and Edward Farrior, MD. “Genioplasty.” eMedicine, June 7, 2002 [cited April 20, 2003]. http://www.emedicine.com/ent/topic106.htm.

Chang, E. W., S. M. Lam, M. Karen, and J. L. Donlevy. “Sliding Genioplasty for Correction of Chin Abnormalities.” Archives of Facial Plastic Surgery 3 (January-March 2001): 8–15.

Danahey, D. G., S. H. Dayan, A. G. Benson, and J. A. Ness. “Importance of Chin Evaluation and Treatment to Optimizing Neck Rejuvenation Surgery.” Facial Plastic Surgery 17 (May 2001): 91–97.

Galli, Suzanne K. D., MD, and Philip J. Miller, MD. “Chin Implants.” eMedicine, May 15, 2002 [cited April 22, 2003]. http://www.emedicine.com/ent/topic628.htm.

Grossman, John A., MD. “Facial Alloplastic Implants, Chin.” eMedicine, July 5, 2001 [cited April 21, 2003]. http://www.emedicine.com/plastic/topic56.htm.

Jafar, M., and R. A. Younger. “Screw Fixation Mentoplasty.” Journal of Otolaryngology 29 (October 2000): 274–278.

Meszaros, Liz. “Sliding Genioplasty Successful in Correcting Chin Abnormalities.” Cosmetic Surgery Times September 1, 2001.

Patel, Pravin K., MD, Hongshik Han, MD, and Nak-Heon Kang, MD. “Craniofacial, Orthognathic Surgery.” eMedicine, December 27, 2001 [cited April 21, 2003]. http://www.emedicine.com/plastic/topicl77.htm.

Siwolop, Sana. “Beyond Botox: An Industry’s Quest for Smooth Skin.” New York Times March 9, 2003 [cited March 9, 2003]. http://www.nytimes.com/2003/03/09/business/09FACE.html.

ORGANIZATIONS

American Academy of Facial Plastic and Reconstructive Surgery (AAFPRS). 310 South Henry Street, Alexandria, VA 22314. (703) 299-9291. http://www.facemd.org.

American Society of Plastic Surgeons (ASPS). 444 East Algonquin Road, Arlington Heights, IL 60005. (847) 228-9900. http://www.plasticsurgery.org.

FACES: The National Craniofacial Association. P. O. Box 11082, Chattanooga, TN 37401. (800) 332-2373. http://www.faces-cranio.org.

OTHER

American Academy of Facial Plastic and Reconstructive Surgery. 2001 Membership Survey: Trends in Facial Plastic Surgery. Alexandria, VA: AAFPRS, 2002.

American Academy of Facial Plastic and Reconstructive Surgery. Procedures: Understanding Mentoplasty Surgery. [cited April 20, 2003]. http://www.facialplasticsurgery.org/patient/procedures/mentoplasty.html.

American Society of Plastic Surgeons. Procedures: Facial Implants. [cited April 20,2003]. http://www.plasticsurgery.org/public_education/procedures/FacialImplants.cfm.

Rebecca Frey, Ph.D.

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