By Dr Leow Aik Ming
The chin, also known as the mentum, has a significant effect on the facial appearance of a person. By undergoing a genioplasty, patients can alter the overall profile and symmetry of their face. Chin surgery or genioplasty is a cosmetic surgical procedure to improve the shape and appearance of the chin. Surgical goals include creating an aesthetically pleasing lower facial contour and establishing proportionate facial height. This may entail augmentation of a poorly projected chin or reduction of a prominent chin depending upon the clinical conditions. Conditions of chin deficiency which can be improved with augmentation genioplasty include: retrogenia, microgenia, retruded chin, hypoplastic mentum, and horizontal mandibular hypoplasia. Likewise, reduction genioplasty can be performed for overprojected or prominent chin, eg, prognathia or protruded chin. In some cases, genioplasty may be performed with other facial plastic surgical procedures such as rhinoplasty, facial contouring surgery or facelift in order to achieve desirable facial proportion.
Types of Genioplasty:
- Augmentation genioplasty: This surgical procedure commonly uses alloplastic chin implant such as silicone, polytetrafluoroethylene or polyester mesh. Alloplastic chin implants, in general, are easy to place and are less time consuming, but their application is limited to the mild to moderately retruded chin. Autografts such as bone graft from iliac crest and rib cartilage graft have also been used.
- Sliding genioplasty: This procedure is reserved for more complex chin deformities, such as those caused by genetics, trauma or disease. The procedure involves cutting a horseshoe-shaped piece of bone from the lower border of the mandible known as an osteotomy. For chin augmentation, the piece of bone is advanced forward to increase to projection of the chin. The piece can also be recessed backward or removed for a chin reduction. The new position is held in place with a titanium step plate using titanium screws.
- Osseous genioplasty: It is performed either horizontally, vertically, or a combination of both. A horizontal genioplasty is ideal for chins that protrude outwards, while a vertical genioplasty is appropriate for removing or adding bone tissue to either increase or decrease chin length. In some cases, however, both horizontal and vertical changes are required to achieve the patient’s desired results. Fixation of the bone is done with pre-bent titanium plates and screws.
Genioplasty can be performed through an incision inside the lower lip or below the chin. The choice of anaesthesia depending upon complexity of the procedure, for example augmentation genioplasty with alloplastic chin implant can be comfortably performed under local anaesthesia with intravenous sedation whereas more complex genioplasty such as sliding or osseous genioplasty usually requires general anaesthesia.
Preoperative assessments for genioplasty include:
- Discussion about patients’ expectations and desired outcome
- Medical conditions, drug allergies and previous medical or surgical treatment
- Use of current medications, vitamins, herbal supplements, alcohol, tobacco and drugs
- Previous surgeries
- Examination of the face, oral cavity and dentition
- Radiological assessment
- Discussion of types of anaesthesia
- Photography for preoperative and postoperative evaluation
During the initial healing phase, patient may experience discomfort, numbness, bruises and swelling around the chin. These symptoms are temporary; usually last about 2-3 weeks. Most of the genioplasty are performed through incision in the mouth. Hence there is no need for stitch removal. However, if this surgery is done through incision made below the chin, the stitches are removed on the 7-10 days after the surgery. Oral antibiotics and analgesics will be prescribed to reduce the risk of infection and postoperative pain respectively.