We instinctively know an attractive smile when we see one. But although our perceptions are subjective ("in the eye of the beholder"), there are understood aesthetic principles that shape them. For smiles in particular, proportionality is one such principle.
More specifically, an attractive smile's visible gum tissue should be proportional to its visible tooth surface. If the gum amount exceeds this, then the smile will appear too "gummy." There's no set measurement, per se, but most dentists peg it at around four millimeters—just over an 1/8 of an inch—or more.
Fortunately, there are options for improving a "gummy" smile. Notice that we said "options," plural: That's because over-exposed gums can occur due to a variety of causes.
Obviously, an actual over-abundance of gum tissue could be one of those causes. It might also result, however, from the teeth appearing and being too small, less than 10 mm of visible crown length, because the teeth are in themselves abnormally small or they failed to erupt completely during development.
There are also causes beyond the actual teeth and gums. The upper lip may move too far upward while smiling—a problem known as hypermobility—revealing too much gum tissue. The upper jaw may also appear too long because of the position of its attachment to the base of the skull. This in turn might result in too much gum tissue displaying while smiling.
Uncovering a gummy smile's underlying cause thus determines the right treatment to pursue. For oversized gums or undersized teeth, a periodontist might choose to perform a plastic surgery technique called crown lengthening. This procedure reduces and reshapes the gum tissues and underlying bone to expose the full length of the teeth.
Lip hypermobility could be limited temporarily by Botox injections administered about every six months. Another option is a surgical procedure that restricts lip movement and can offer a permanent solution. Similarly, surgery to reposition a long upper jaw could minimize gum exposure and improve smile appearance.
If you or a family member has a gummy smile, there may be an effective way to improve it. Understanding why it's gummy will be your first step to a more attractive smile.
If you would like more information on enhancing a gummy smile, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Gummy Smiles.”