Chicago — Augmenting the facial soft tissues provides a different visual effect than augmenting the facial skeleton with alloplastic implants, according to an expert in facial skeletal surgery.
There's a misconception that changing a patient's face by augmenting soft tissue can yield the same results as skeletal augmentation, says Michael J. Yaremchuk, M.D., professor of surgery at Harvard Medical School and chief of craniofacial surgery at Massachusetts General Hospital, Boston.
"That's not true," he states. "If one augments the skeleton with alloplastic implants, the face becomes more defined. If one augments the soft tissues with a soft tissue filler or fat, one may be projecting the soft tissue envelope, but one is softening the contours and making the face less skeletal."Beyond a millimeter or so of augmentation, Dr. Yaremchuk says, the effects of these treatments diverge.
"Each treatment modality has a different indication. Soft tissue augmentation is usually performed to replace soft tissue volume lost secondary to the aging process. Skeletal augmentation is usually performed on younger patients who desire a change in their basic skeletal morphology," he adds.
Porous polyethylene implants
For skeletal augmentation in areas ranging from the orbit, malar and paranasal areas to the chin and mandible, Dr. Yaremchuk prefers porous polyethylene implants to those made of smooth silicone.
"The advantage of the porous polyethylene is that the pore size allows some soft tissue ingrowth, so that these implants tend to become incorporated rather than encapsulated, which is what happens with smooth implants," says Dr. Yaremchuk, whose implant patients are almost exclusively cosmetic rather than reconstructive.
Particularly, if one places large smooth implants under thin soft tissues, he says, "Because of the capsular contracture process, one tends to see the smooth implants in relief. With porous implants, that's less of a problem."
Dr. Yaremchuk further recommends fixing porous implants to the skeleton with screws. This way, he says, the implant adapts to the skeleton and eliminates gaps between the two surfaces that could result in unpredictable and unanticipated increases in augmentation. Such an approach, he adds, allows precise augmentation and prevents the implant from moving over time.
"The screw fixation also allows me to custom tailor the implant once it's in place," Dr. Yaremchuk says.
Cheeks, chins and eyes
A common procedure he performs involves placing malar implants in patients who desire more prominent cheekbones.
In such cases, he says, "I make sure to put the implants on the bone, not beneath the malar bones, so that the resulting contours appear normal."
Chin augmentation with porous implants also ranks among the more common procedures Dr. Yaremchuk performs. In this area, he begins by determining how much projection the patient requires.
"I do that by looking at frontal and lateral views and comparing them to normal values for chin projection in both men and women," he says. "In general, men have more projecting chins, so one must be careful not to make a woman's chin project too far. A mistake some surgeons make is that in order to get better neck definition in a facelift, they'll put a chin implant in a woman's face. It may improve their neck contour, but if the chin projection is already adequate the chin implant may have a masculinizing effect."
Dr. Yaremchuk tells Cosmetic Surgery Times he always performs chin implants through a submental incision, not through the mouth.
"If one goes through the mouth, one can damage the mentalis muscle, which can lead to malpositioning of the lower lip and chin pad," he says. Furthermore, he employs a wide subperiosteal exposure so he can see all the surface contours of the chin, as well as the position of the mental nerve, which one must avoid impinging.
Using a two-piece implant allows each piece to conform to the border of the mandible in a way that a one-piece implant rarely does, Dr. Yaremchuk adds. After fixing the implant with screws, he custom tailors it.