• Other types of problems: There is the unlikely chance (less than 1%) that a blood   vessel may be hit or blocked during an injection. If this occurs a bruise may form at the   site or a scab may occur with subsequent sloughing or shedding of the skin. This   could result in a shallow scar. Because this is more likely to occur when treating the   vertical creases between the eyebrows some dermatologists are now opting to use   localized muscle relaxants (Botox: botulinum exotoxin). The relaxants, when injected   into the muscles above the eyebrow cause a temporary paralysis so an individual can   no longer frown. The temporary muscle inactivity reduces the wrinkles.

If collagen is injected into a vein near the eye, visual loss could occur. Only one incident of this happening out of millions of injections has been reported so the risk is extremely low.

At the time of implant therapy it is wise to avoid the use of aspirin or other types of nonsteroidal anti-inflammatory drugs that reduce the clotting of the blood. This will help control bleeding and bruising at the treatment site. If there is a history of herpes simplex, the trauma caused by the injection of the collagen may stimulate the eruption of a herpes cold sore at the site of the injection.

• Safety with pregnancy: Whether or not implants can be safely injected during   pregnancy or breast feeding has not been established, so it is better to wait until after   the postnatal period before embarking on an implant therapy program.

What about inorganic implants?
Artecoll is the most promising of the inorganic implants because it is easy to deliver through injections and the results are permanent. The limitations however include: excessive swelling and hardening of the area injected, asymmetry, the permanent feel of the microspheres under the skin and the results cannot be undone.

Silicone implants are controversial. If incorrectly used, silicone has many potential complications, largely because it is unforgiving. Once silicone is in place, it is permanent. This is good, if properly placed. On the other hand, if a low-grade silicone solution or an unnecessarily large amount is used by an unskilled clinician, the error is permanent. This is because silicone is not slowly absorbed by the body as in the case of theorganic implants. Silicone may be perceived by the body as "foreign", and reactions may occur in the form of an allergic granuloma (or bump). Tracking or