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Lee et al. Plast Aesthet Res 2018;5:43 I http://dx.doi.org/10.20517/2347-9264.2018.39 Page 7 of 9
[14]
Temple - volume loss in the temples leads to prominence of the bony orbital rim and lateral brow ptosis .
A more robust product with a high G’, such as Juvederm Voluma®, Restylane Lyft®, or Radiesse® (a calcium
hydroxylapatite product), is preferable in this area. When introducing filler in this region, care must be
taken to avoid both the blood vessels and branches of the facial nerve coursing through this area. Recall that
the path of the facial nerve as it courses through the superficial temporal fascia may be roughly estimated by
[15]
drawing a line from 0.5 cm inferior to the tragus to 1.5 cm superior to the lateral brow . Injection should
be initiated in the area of greatest volume loss and typically at least 1 cm lateral to the lateral orbital rim. A
deep plane under the fascia of the temporal muscle on the periosteum is generally safe and also provides a
nice cosmetic result. Injection volume varies from less than 1 to over 2 mL per side depending on the degree
of correction required.

Filler may also be used to address static rhytids in combination with toxin injection, as well as to restore
volume and arch to the lateral brow, crows’ feet and glabella.

Potential complications
Complications of dermal filler injections include Tyndall effect (a bluish hue to the skin resulting from
superficial filler injection), irregular surface contour, hypersensitivity reaction and/or granulomatous
inflammation, and the development of festoons or chronic fluid collections. The most serious potential side
effects include vascular occlusion leading to tissue necrosis or worse, blindness from retrobulbar hemorrhage
or central retinal artery occlusion. In general, proper injection technique and depth minimize the risk
of poor cosmetic outcomes such as the Tyndall effect or contour irregularities. As mentioned above, the
choice of filler with low water affinity is important to avoiding the development of chronic fluid collections.
Vascular occlusions are discussed in more depth below.

Vascular occlusion and ocular ischemia: the most devastating potential complications of
dermal filler injection
Intra-arterial injection of filler may result in vascular occlusion with either anterograde or retrograde
embolus of product. Local embolus can lead to soft tissue necrosis or a distant embolus can lead to
permanent blindness. If the force of intra-arterial injection is greater than mean arterial blood pressure,
retrograde flow can potentially introduce filler into the ophthalmic or central retinal artery, or long and short
posterior ciliary arteries, leading to visual loss. More proximal flow may introduce filler into the middle
cerebral artery resulting in cerebral infarction. If tissue necrosis should occur, there are several important
steps to take to restore perfusion. First, warm compresses can be used to promote local vasodilation (this
low risk treatment is theoretically helpful, although there is no data to support its efficacy and there is some
worry that vasodilation can encourage an embolus to flow further distally). Topical nitroglycerin may also
be used to promote vasodilation, with the same theoretical advantages and disadvantages. Again, there is
[16]
no evidence proving its effectiveness . Second, the area should be flooded with injected hyaluronidase;
this is the only proven treatment for this complication. Generally, subcutaneous injection is thought to be
sufficient, but intra-arterial administration may also be considered if possible and time allows. Practically,
reintroduction of the needle into the occluded artery may not be possible, and prior studies have shown that
[17]
extravascular hyaluronidase is effective on the intravascular material .
It is important to have a large volume of hyaluronidase easily accessible for prompt treatment; we
recommend at least 10 (unexpired) vials. There are a variety of hyaluronidase formulations available, which
may be of human recombinant or animal derived origin. Characteristics such as storage parameters,
preservatives, units per vial, and reconstitution requirements vary. Although different types of filler
may respond to hyaluronidase differently, there is no evidence to suggest that a specific hyaluronidase
[18]
formulation is more effective . Although there are rare reports of allergic reactions to hyaluronidase, skin