The true science of lip augmentation requires an understanding of the upper and lower lip relationship, lip style, and lip contour. Historically practitioners are treating lips with little understanding of lip forms. They simply fill them like tires causing sausage lips or the famous trout mouth or duck bill appearance seen all to often in Hollywood tabloids.  The first principle is the relationship between the upper and lower lip, the most basic aesthetic point. The next principle is lip style or shape like the Cupid’s style. The final principle is lip contour, the height of the vermillion lip border viewed from the side silhouette.The goal with lip augmentation is to avoid making both upper and lower lips the same size. It is more aesthetically pleasing depending on the patients face and natural lip shape to have the upper lip slightly larger than lower lip, or most common the lower lip slightly more pouted the the upper lip. Either one of these styles is natural and attractive in appearance, especially if it hits the ‘golden mean’ or ‘golden proportion’ of 1 to 1.618 the magic number that seems to elicit a pleasing aesthetic to the human eye.