Lip augmentation is most commonly done by injection techniques. While effective lip injections are limited by either the temporary duration of their effects or the unpredictability of injected fat survival. Other materials have been implanted into the lip (dermal grafts/substitutes) but they all suffer similar outcome fates. Despite the limited effects of injectable lip fillers, this is always a good place to start to determine if volumetric addition alone produces the desired lip augmentation effect.
The only assured volumetric augmentation method are lip implants. Contemporary lip implants are made of an ultrasoft solid silicone material. They are available in 3, 4 and 5mm diameters (centrally) and of varying lengths to fit different lip lengths. (mouth corner to mouth corner) The advantage of a non-tissue adhering implant surface is that it makes their introduction and retrieval/removal uncomplicated. Past lip implant history has shown that the concept of tissue ingrowth into an implant material is a flawed one should removal or adjustment be needed.(which is not rare)
Placement of lip implants requires a special passing instrument whose use is a necessity to properly place them. The curved passer is placed through the lip from one corner to the other. Onto the opened instrument goes one end of the implant which is grasped and then pulled through to the other side. While this sounds simple enough the reality is that it is very sensitive technique as getting placement of a lip implant at an even level across the curved shape of the lip is trickier than it looks. Unevenness of lip implant placement is the number #1 aesthetic complication of their use.
Another potential aesthetic complication is a lip implant that is too short for the lip length and moves around afterwards. (slides back and forth) While this theoretically is avoided by having an adequately long implant between the two corners of the mouth, small discrepancies in length can make for some buckling (slightly too long) or sliding. (slightly too short) This is the one downside to having an implant that lacks tissue adherence. It is important once the implant is passed into the lip that the ends are still grasped on both sides and the lip is stretched out over the implant. This allows for a better appreciation of the lip vs implant length.
Lip implants have a unique set of aesthetic complications because of their soft tissue location in a highly sensitive and tactile facial feature. While effective for creating a permanent volume effect, they have a relatively high rate of aesthetic issues which ultimately are often only solved by their removal. While tissue adherence may solve some these issues, it is far better to not have tissue adherence which can make secondary adjustment/removal complicated.
Dr. Barry Eppley