Excessive Gingival Display - ""Gummy Smile""
Excessive gingival display, also referred to as a “gummy smile”, can be attributed to one or more of the following factors: 1) gingival overgrowth, 2) altered passive eruption, 3) vertical maxillary excess (VME), 4) short upper lip, 5) hypermobile upper lip, and 6) dentoalveolar extrusion.75 Careful clinical examination can distinguish between these underlying conditions. It is critical that the dental healthcare professional is able to assess clinical crown height, lip length and mobility, and vertical facial third symmetry to identify one or more contributing factors for excessive gingival display.76,77 If the excessive gingival display is associated with gingival overgrowth or altered passive eruption, patients will present with short clinical crowns and either excessive gingival tissues or excessive gingiva and alveolar bone, respectively.2 Patients with altered passive eruption have a periodontal attachment apparatus at a position that is more coronal than anatomic norms, which can be determined radiographically and through bone sounding. These patients should be treated with resective surgical interventions—generally gingivectomy or esthetic crown lengthening—and they should also have an evaluation of potential underlying systemic conditions or medications that may contribute to gingival overgrowth.78 Both VME and a short upper lip may present with lip incompetence, but lip length will be normal in cases of VME.2 VME is associated with a lengthening of the lower facial third, which can be assessed in a facial photograph at rest. VME may be addressed with orthognathic surgery and a short upper lip would require a lip lengthening surgery to reduce gingival display.77 Individuals with excessive gingival display related to lip hypermobility present with normal lip length with increased mobility during dynamic lip movement. This can be assessed using video capture of a patient smiling and/or speaking. Addressing this may require lip repositioning surgery and/or treatment with botulinum toxin to reduce facial muscle hyperfunction.77-79 Dentoalveolar extrusion occurs due to over-eruption of maxillary incisors. In addition to excessive gingival display, patients with dentoalveolar extrusion present with increased clinical crown length, potential lip incompetence, and alteration of tooth arch curvature.77Treatment should include orthodontic intrusion of the supraerupted incisors. In some cases, patients may present with multiple underlying etiologies for excessive gingival display and coordinated interdisciplinary care may be necessary to achieve optimal results.77
Figure 10: Excessive Gingival Display may be due to 1) gingival overgrowth, 2) altered passive eruption, 3) vertical maxillary excess (VME), 4) short upper lip, 5) hypermobile upper lip, and 6) dentoalveolar extrusion.