Facial skeletal imbalances present in many manifestations. Most commonly these are perceived from the profile view as maxillary and mandibular discrepancies in the mid- to lower face. Often they are reflected as changes in one’s occlusion when the bone deficiencies become significant enough. In these cases, orthognathic surgery is used for facial skeletal correction. Despite this surgery, all areas of facial bony deficiencies may not be aesthetically improved.
Facial osteotomies only change certain bony prominences and aesthetic facial highlights. It is important in orthognathic surgery, therefore, to recognize what will or will not be changed by maxilla-mandibular repositioning. A perfect occlusion is great but an opportunity to add to an improvement in one’s facial appearance can be missed if not diagnosed and treatment planned.
In combination with or after orthognathic surgery, several treatment areas exist. The level of the commonly-performed LeFort I osteotomy is below the cheek and orbital area. It only moves the tooth-bearing portion of the upper jaw. (maxilla) This leaves the cheek bones and the infraorbital rim unchanged. Cheek implants and newer styles of infraorbital rim implants can do what no osteotomy can. Ideally, the benefits of such implants are recognized before the orthognathic surgery so they can be done simultaneously. This is particularly convenient for cheek implants which are placed through the same incision as that of the maxillary osteotomy. Paranasal and premaxillary implants offer increased projection of the nasal base, the central portion of the midface above the teeth. They can be safely used at the same time as a LeFort osteotomy.
Mandibular osteotomies do a great job of changing horizontal position but no changes ever happen in width. This can leave the jaw angles deficient which often occurs after a sagittal split mandibular osteotomy. Implants can dramatically change the shape and width of the jaw angle but should not be used at the time of an osteotomy due to increased risks of infection and impairment of bony healing. They may be desired later, particularly if some bony resorption of the jaw angle has occurred which is not rare. The common chin implant has a role both during and after jaw repositioning surgery. While an osteoplastic genioplasty is often done for additional chin advancement at the time of an osteotomy, one can always substitute a chin implant if the main movement desired is solely horizontal in direction. Good preoperative treatment planning should avoid the need for chin implants later. But bony irregularities and asymmetries may be treated by extended or even custom chin and jawline implants.
For those patients who have residual facial bone deficiencies after orthognathic surgery or have bony deficiencies recognized as part of orthognathic surgery treatment planning, facial implants offer a viable option. The variety in size and shape of facial implants, whether off-the-shelf or from custom designs, today offers numerous safe and effective treatments as an adjunct to orthognathic surgery to create the visual illusion of actual bony movements.
Dr. Barry Eppley