Lip Mobility

When a patient smiles, the upper lip will elevate and display the maxillary incisors. Symmetry of movement in this case allows for uniform display and is considered esthetic.²³Mean lip mobility results in a reduction of 80% of the original lip length and a subsequent display of maxillary anterior teeth of approximately 10mm with a natural smile.²³ Physiologic lip mobility ranges from 2-12mm, but considerable heterogeneity is present among individuals.²⁶Lip mobility is greater in women compared to men and women are more likely to have excessive lip mobility.²³ Such excessive lip mobility may cause excessive gingival display during full smile despite normal lip length (Figure 6).

Figure 6: Excessive gingival display related to lip mobility during full smile.

Figure 6: Excessive gingival display related to lip mobility during full smile.