Chin augmentation

Chin augmentation is a cosmetic surgery used to improve an under-projected chin, or an unusually small or deformed chin (microgenia).

It is a common facial surgery and can be performed by a plastic surgeon or a maxillofacial surgeon. The two main methods for chin augmentation are:

1. inserting an implant: implants are used for mild-to-moderate deficiencies
2. skeletal surgery: this offers versatility and is helpful in severe cases

Chin augmentation is often performed along with other surgeries such as rhinoplasty (nose reshaping) and neck lift (to improve visible signs of ageing in the jawline and neck) or facelift (to enhance the jawline). The procedure is performed under local anaesthesia or general anaesthesia, depending on the doctor’s assessment.

The choice to go for chin augmentation is of the person themselves for restoring facial harmony. There is usually no medical reason for this. Indications that a chin augmentation can be performed are:

• The person is physically fit and has a stable weight
• The person is bothered by their chin’s appearance
• The chin is small or recessed
• The person does not smoke
• Pre-existing conditions such as diabetes are under control

It is important for the person to discuss their expectations with their doctor and to understand the realistic outcomes.

The following are the contraindications of chin augmentation:

• Having long teeth with suboptimal vertical chin height (viz. short mandibular height – mandible refers to lower jaw or jawbone)
• Retrognathia (deficient growth of the jaw) associated with misaligned teeth (dental malocclusion)
• Previous rejection of implanted material
• Deep labio-mental fold
• Lip protrusion
• Labial incompetence (strain while closing lips together)
• Periodontal disease (dental carries or cavities)

Prior to the surgery, the doctor takes a complete history of the patient and their overall health. This includes:

• Evaluating pre-existing health conditions
• Drug allergies and medical treatments
• Alcohol, tobacco or drug use
• Current medications and health supplements
• Previous plastic surgeries

Certain medications such as anticoagulants, anti-inflammatory drugs, aspirin or herbal supplements may be stopped or altered a few days prior to surgery. The doctor may also prescribe antibiotics to reduce the chances of infection.

Certain tests are also carried out to evaluate facial symmetry. There are various methods for it that a doctor can use including examining the proportion of the nose and chin in relation to the face, degree of retraction, cephalometric study, etc.

Other tests that are carried out are:

• X-rays and MRI scans of the face from a few angles to assess asymmetry
• Study of the soft tissue in the maxillofacial area
• Photography: multiple photographs from various angles are taken with the patient smiling and at rest
• Alignment of the teeth and skeletal structures is also studied
• Evaluating whether dental or skeletal deformities may be present

After concluding the above tests, the surgeon recommends the likely outcome of chin surgery and the potential risks and complications. If it is determined that general anaesthesia will be used for the surgery, the patient is advised to arrange for a ride home.

In the case of implants, the type of implant and its size is also selected. Some of the common implants are silicone, high-density porous polyethene or meshed material.

There are two methods for performing chin augmentation: chin implants and sliding genioplasty.

Before the surgery, local or general anaesthesia is administered. The operative area is cleaned and topical antiseptic is applied. Thereafter, surgical markers are used to highlight planned incision sites.

Chin Implants

There are two approaches for chin implants:

• Submental: in this, an incision is made outside, under the chin. A tight pocket is created in front of the chin bone and under the muscles. The implant is removed from its sterile packaging and inserted and set in the proper position. The implant is then secured using stitches or screws. The wound is then carefully closed using sutures, with special attention to the reattachment of the muscle. A dressing is then applied with antibiotic ointment using non-adhesive gauze and adhesive tape.
• Intraoral sulcus: in this, an incision is made inside the mouth. Once the implant is in place, the wound is liberally irrigated with antibiotic solution and then closed in layers using absorbable sutures, with care to create a watertight seal.

Sliding Genioplasty

This method is also called osseous genioplasty and is generally performed under general anaesthesia. The surgeon pulls down the lower lip and infiltrates the area with a diluted solution of adrenaline to have reduced bleeding. An incision is then made on the gum below the lower teeth. The soft tissue is then carefully separated from the chin bone.

A mid-line is marked and the surgeon then uses a saw to cut a small vertical line, to ensure that the chin stays straight after it is moved forward. Then a horizontal cut is made along the chin bone to slide the bone forward (and sideways as determined). To make the chin longer, a gap may also be left between the chin and the rest of the jaw – this gap gets filled over time as bones grow. In case the chin bone is moved forward, it may create a step. This would be more visible in females due to a lack of facial hair, and to prevent this, the surgeon may shave off some of the bone.

After fixing the chin, it is then attached using screws, (resorbable) plates or stainless steel wires. Post this, the incision is closed in multiple layers with absorbable sutures. A compression tape is also placed on the outside of the chin to reduce post-operative swelling.

The risks and complications depend on the type of surgery performed. Some of the complications are:

• Reactions to anaesthesia: nausea and vomiting
• Infection
• Internal bleeding
• Nerve or muscle damage
• Allergic reaction to the implant
• Exposure of screws
• Bone resorption: the destruction of the bone tissues
• Implant displacement
• Extrusion of implant
• Dehiscence of the wound
• Over-projection
• Asymmetry
• Step-type deformity
• Abnormal healing of the bones: malunion or nonunion
• Displacement
• Lower lip retraction
• Chin ptosis: sagging of the stretched skin

In case of signs of infection, such as persistent fever, swelling or bruising, strong odour, or bleeding which does not stop with light pressure, the doctor needs to be notified immediately. Other symptoms in which prompt contact with a doctor is required are shortness of breath, chest pain, and unusual heart rate.

Slight resorption is found to occur over some time.

Since this is a daycare procedure, the patient is discharged on the same day. Swelling, redness and bruising are common and disappear within a week.

The discharge instructions typically include:

• Using an ice pack to reduce swelling
• Take antibiotics for a few days to prevent infection.
• Soft food or liquid diet for some days
• After each meal, rinse the mouth with water and an antiseptic oral solution
• Wound dressing and compression tape can be removed after three to five days

Follow-up is typically scheduled seven to ten days after surgery, during which the doctor evaluates the wound for any signs of infection. Any external sutures are also removed. The patient is also advised for follow-up visits 1 month, 3 months, 6 months and 1 year post-surgery and thereafter on an annual basis.

Chin augmentation is a common and straightforward procedure used to improve an under-projected chin. Studies suggest that more than 90% of patients are satisfied with the outcomes of this surgery. It carries minimal risks, with the major one being facial deformity. Once the swelling goes down, the results are visible.