The subnasal lip lift is a well known upper lip reshaping procedure. By removing an irregular pattern of skin from the nasal base area, the upper lip is vertically shortened. With that comes an increase in the size of the cupid’s bow region with some increase in upper tooth show as well.
But it is important to recognize that the subnasal lip lift is not a total upper lip reshaping procedure. The horizontal distance of the subnasal skin excision vs the length from one mouth corner to the other is not a 1: 1 ratio. It is always less which results in the mouth corners for sure and usually the outer third of the upper lip unaffected by the more central upward pull to close the skin excision site.
For this reason subnasal lip lift patients are at risk for creating an upper lip vermilion size mismatch, known as the rabbit look, in certain situations. The most common reason is if too much of the philtral skin distance is reduced. (always safe to keep the amount of vertical skin excision no more than 25% to 33% of the philter length. It can also occur when the upper lip vermilion is very thin on the sides and becomes out of balance when the center gets bigger. It is also a risk when secondary subnasal lip lifts are performed which, by definition, may exceed the 1/3 vertical distance excision guideline.
When the risk of a vermilion imbalance exists in a subnasal lip lift this can he avoided with the addition of lateral vermilion advancements. By directly advancing the vermilion edges that lie outside the influence of the subnasal lip lift, vermilion height balance is maintained from one mouth corner to the other. This is done immediately after the lip lift is completed. It has a tapered skin excision design from a medial point established by a vertical line dropped down from the side of the nostrils. The excision pattern gets larger as it approaches the mouth corners before acutely tapering to it.
There is a fine line scar tradeoff but it usually does well if carefully executed and with this small amount of skin removal.
Dr. Barry Eppley