Evaluating Facial Esthetics: Lip Fullness

In a recent article, I discussed the importance of evaluating lip symmetry when planning esthetic treatment, specifically focusing on the ramifications of having an asymmetric upper or lower lip. In this article we are going to look at another variable that impacts the final esthetic result, lip thickness or fullness. Of course it is important to recognize that today lip fullness is something that can be altered by a number of different procedures, so I will simply focus on the ramifications of different lip thicknesses, not how they got there.

An easy analogy to use for understanding lip thickness is to think about taking a piece of art to be framed. At most frame shops they have a large selection of frames you can place on the corner of your artwork to see the impact. The first thing I always notice when I do this is the difference between trying on a thick frame compared to a thin one. The thick frame will always make the art seem smaller and less dominant, while the thin frame can make the art appear to dominate, and leaves the frame looking very small.

The same is true for lips and teeth, the thicker the upper lip, the smaller the teeth will appear. This is why if a patient is going to consider having any procedure done to enhance the thickness of their lips, that procedure should be done prior to any esthetic dental procedures. So how do we alter teeth to compensate for variations in lip thickness? By altering tooth size and shade. First we'll discuss size.

As I have discussed in previous articles the range of size of unworn human central incisors varies from 9 to 12mm, with 10.5mm being the average. For patients with an extremely full upper lip it may be necessary to use 11 or even 12mm centrals to create a pleasing balance to the full lip. The reverse is true for patients with extremely thin lips, where a 9.5 or even 10mm central may be more appropriate. All of this of course must be tried in the provisional restoration and refined there.

The other challenge of an extremely full upper lip is shade, more specifically brightness or value. An extremely full upper lip will cast a heavy shadow onto the upper anterior teeth anytime there is an overhead light source; this shadow can make even normal shades look quite dark.

The solution to the challenge of choosing the right size and shade that I use is quite simple. Start by having a diagnostic wax-up done at what you believe will match the largest central you may consider, for me typically that would be somewhere between 11 to 12mm. This way after placing a mock-up or provisional you can see how the largest size looks, and if you don't like it, it is easy to shorten the provisional as compared to adding length. Second make the provisionals brighter then you think they should be, by 1 or 2 shades, you now get to see how the full lip impacts the appearance of the teeth relative to their apparent brightness. If they appear too bright, it is a simple task to tone them down with a little external color. The other option of course is to forego the diagnostic wax-up and do a direct mock-up in the mouth, which I know is a choice many prefer.

A full lower lip isn't as challenging as a full upper lip since the lower lip has no impact on apparent brightness. A full lower lip does have the same impact on the apparent size of the teeth, just as the thick frame does on a piece of artwork, the fuller the lower lip the smaller the teeth will appear.

The patient in figure 1 is a female with natural, but quite full upper and lower lips. Her chief complaint is she thinks her teeth are too small, and too dark, even though the centrals measure 10mm and they are shade A-1. To determine if we could satisfy her desires I would go through the same procedures I outlined above concerning a diagnostic wax-up, but I would make a putty matrix of the wax-up and using a light shade of provisional material load the matrix and seat it on her teeth. After it was hard you can remove the matrix and she is now wearing a tooth colored version of the wax up in the form of a mock-up. This will allow us to communicate the potential tooth size and shade options with her prior to any treatment.

The patient in figure 2 is an example of a very thin upper lip, and average to thin lower lip. I performed the reconstruction of his upper arch, the premolars are shade A-2, the canines and molars A-3, and the maxillary centrals are only 10mm long, yet the thin lip makes them appear brighter and larger then they really are.