Temporal hollowing, also known as narrow or indented temples, gives the face (head actually) an unnatural hourglass shape. Rather than a convex transition from the side of the head into the upper cheek area, temporal hollowing shows a concave or sunken contour. Temporal hollowing occurs due to a variety of reasons. Most commonly, it occurs after neurosurgery where a long scalp (bicoronal) incision is used to perform a craniotomy either for tumors or skull fractures. It can also occur as part of certain diseases or medication use that causes facial fat loss. (e.g., HIV) Less commonly, it may also exist as one’s natural anatomy in thinner faces.
Such hollowing can be aesthetically improved through a procedure known as temporal augmentation. There are different materials and methods for changing the tenmporal contour from concave to convex.The key to choosing a successful augmentation method that has a low risk of complications is the condition of the temporalis muscle. Is the muscle completely normal as in the aesthetic patient or is it contracted and thinned from prior surgery or irradiation? The origin of the temporal hollowing, combined with physical examination, will reveal the condition of the muscle.
The temporalis muscle is a large fan-shaped muscle that originates from the temporal line of the skull and extends to insert onto the moveable lower jaw down below. Even in severe atrophy (shrinkage), the temporalis muscle is still moderately thick down near the zygomatic arch. The condition of the muscle higher up is where temporal augmentation takes place and is where the muscle may be most abnormal.
There is no implant material that is universally agreed upon for temporal augmentation. In cases of temporalis muscle atrophy, I prefer in my Indianapolis plastic surgery practice a bone-based approach to implant placement and try and get as much muscle pulled up over it as possible. I prefer a bone paste (hydroxyapatite cement) which is well tolerated and allows for intraoperative custom shaping. I have also used synthetic meshes (most commonly used in abdominal hernia repairs) folded into many layers to achieve the same effect. Given that the implant should ideally end up under the muscle, it is likely that the choice of material is not that important. Also, this type of temporal contouring uses a long scalp incision (which is likely already present from prior surgery) as direct vision and wide open access is needed for their placement and muscle resuspension.
Cosmetic temporal augmentation, however, is different. With a normal muscle, an implant material can be placed under the unscarred and normal fascia which covers the outer part of the muscle. Thus, a much smaller incision isolated to the temporal region can be used through which  a solid implant can be inserted. To keep the incision small, I prefer a silicone shell implant which is solid enough to slide into the subfascial plane and flexible enough to fit through a more limited incision. Cosmetic augmentations do not usually require as much fill as a reconstructive one. It can be surprising how powerful an effect a relatively thin implant can be. Plus it is important to not overdo the size of the augmentation as a bulge is just as unnatural as a concavity.
There are some off-the-shelf temporal implants available from certain manufacturers but they are usually too large and require a lot of downsizing during surgery. They are more ideally suited to reconstructive cases of temporal hollowing after surgery. New temporal silicone implants are available that are more appropriate for the smaller hollowing in the cosmetic patient.
Fat injections can also be used for cosmetic augmentation but are not appropriate for cases in which the temporalis muscle is not normal. In addition the survival of fat injections in the temporal area is highly variable and this is why a permanent implant in even a cosmetic patient is my preferred approach for temporal augmentation.
Dr. Barry Eppley
Indianapolis, Indiana