There is a lot of discussion re “the perfect lips” in the media and magazines. There is ethnic variability clearly and after that …? Should the ratio of upper lip to lower lip be more 1/1 or 1/1.6? Should the distance between the nose and cupids bow and the bottom lip to chin be the same or a ratio of 1/3? Should the lips be no wider than the distance between the pupils? Some plastics surgeons believe that beauty can be expressed mathematically through these ratios.
My vote is that since we are individuals, the proportions of our lips should be individual, i.e. they should fit our faces, ages, and be modified only to improve the whole picture not just one element. To me, beauty is very individual.