Not only should a lip augmentation pass the "Kiss" Test, it should also pass the "K.I.S.S." Test...
I responded to a patient question on the website realself.com wondering what injectable lip options passed the Kiss Test, meaning a smooth natural result without lumps. I responded along with some of the other physicians responding that Juvederm, Restylane, and fat injections passed the Kiss Test. But I mentioned that it would be wise for plastic surgeons and dermatologists to also consider the K.I.S.S. Test when considering lip augmentation: Keep It Simple Stupid.
Where does this apply? To "permanent" fillers or implants. The good thing about permanent fillers and implants is that they're permanent... the bad thing about them is, they're permanent! If you have a problem with one of these and it needs to be removed, your lip is never going to be the same.
I have seen horrible problems with lip implants - infected implants, broken implants, displaced implants, permanent scar tissue. Even when none of those problems happen, they tend to distort the lip during certain expressions, and they can be felt... so they definitely do not pass the Kiss Test or the K.I.S.S. Test. Don't get them!