Augmentation procedures

Facial augmentation is a widely used procedure to camouflage esthetic disharmonies. The use of alloplastic implants is the standard of care as opposed to autogenous bone, cartilage or soft tissue grafting (except for nasal augmentation).

Despite the variety of implants currently available the porous polyethylene implants are the most commonly used for mandibular augmentation due to their biological and biomechanical characteristics.

Independently of the implant material, the success of the procedure will depend on:

• a detailed patient evaluation
• careful planning (including computer assisted planning)
• adequate surgical technique
• meticulous implant modification (according to the manufacture guidelines)
• stable fixation

Furthermore, special attention should be given to the soft tissue coverage over the implant.

The chin augmentation is performed through the transoral approach to the symphysis.

However, some surgeons prefer the submental approach.

The augmentation of the inferior border and angle is performed through the transoral approach to the angle. The subperiosteal dissection should expose the involved areas.

After bone exposure, the implant is measured against the symphysis and parasymphyseal, or the lateral aspect of the mandible. It is then shaped to produce a perfect fit using one or both of the following techniques:

• Carving with a scalpel
• Bending after heating the implant in warm saline solution

These modifications are intended to allow for the desired aesthetic correction and for a passive fit on the bone surface.

Prior to implant fixation, it is soaked in an antibiotic solution.

The implant is then fixed to the mandible, typically using 2-4 (depending on implant size and shape) monocortical screws.

The surgical retractors are removed and facial symmetry checked prior to wound closure.

Particular care has to be taken to create a water tight seal during wound closure.

To reduce swelling, the application of ice-packs or cooling devices during the early post-operative phase is advice. Intravenous steroids should also be continued for a short period postoperatively for the same purpose.

Antibiotic prophylaxis is continued for 1-5 days depending on the nature, complexity, and duration of the surgical procedure.

Early post-operative x-rays are obtained to verify correct segment position. Additional postoperative imaging is performed as needed.

Regular follow up examinations to monitor healing.

At each appointment, the surgeon must evaluate the patient's ability to perform adequate oral hygiene and wound care and should provide additional instructions if necessary.

Postoperatively, patients will have to follow three basic instructions:

1. Diet
With the intraoral approach in orthognathic chin surgery, wound healing must be supported by a soft diet for 10-14 days, starting with liquids for the first 3-4 days.

2. Oral hygiene
Patients with intraoral wounds must be instructed in appropriate oral hygiene procedures. For a time of up to 10 days care must be taken not to mechanically irritate the wound area. Toothbrush and toothpaste can be applied but must be used carefully. Medical rinses can be used for support.

3. Functional training/physiotherapy
Functional training or physiotherapy are usually not necessary. In case of persistent edema, lymph drainage is recommended.