Smiling is natural, tracing more than 30 million years of evolution and exceeding the language barrier as a means of communication and a universal sign of happiness.
When meeting someone new, your smile is the first thing people notice. Smiles rank the second most attractive attribute by men and women next to personality. In fact, people consider smiling people to be more likable, courteous, and competent.
An aesthetic smile is one that meets the following criteria:
- The symmetrical exposure of the anterior teeth with the maxillary midline is aligned with the face midline
- The teeth should meet the rule of golden proportion that is the perceived width of the anterior maxillary teeth, as viewed from the direct anterior. They should have a ratio of 1 to 0.618 with the tooth adjacent to it.
- The smile arc should be formed with the incisive edges of the maxillary teeth parallel to the lower lip.
- The gingival crest of the maxillary incisors and cuspids should be at the same level.
- The lateral incisors are slightly coronal at about one millimeter.
- The gingival display between the inferior border of the upper lip and the gingival margin of the anterior maxillary teeth during a posed smile should be one to two millimeters apart.
Most dentists prefer that the lip elevation during a posed smile stops at the gingival margins of the maxillary incisors. Some believe that an excessive display of the gums or “gummy smile” is unattractive.
A gummy smile is officially known as an excessive gingival display, a condition where the gum tissue is overexposed. In fact, many consider large gums to be distracting or displeasing. An unattractive smile tends to have more than four millimeters of the gingiva exposed. However, this is not always the case.
The excessive gingival display is more common in women than in men. According to A.H. Tjan et al., only seven percent of men have a gummy smile. On the other hand, women constitute twice the number of men at 14 percent.
Notable personalities that have gummy smiles are American journalist Katie Couric, actress Nicole Kidman, and singer Gwen Stefani.
Age and sex influence the gingival display. As a person ages, the gingival smile line diminishes. Men typically have a lower smile line while women have higher smile line.
Aside from age and sex, etiological factors can cause a gummy smile or excessive gingival display.
Etiological factors include:
- Vertical maxillary excess or protrusion where the lower third of the face is long, or there is lip incompetence
- Overeruption of maxillary incisors where there is an excessive vertical growth of maxillary anterior dentoalveolar
- Short upper lip where the philtrum is shorter relative to the commissures
- Hypermobile upper lip where there is an external elevation of the upper lip or smile due to the hyperfunction of the elevator muscles
- Altered or delayed passive eruption where there is a delayed migration of the gingival margin in an apical direction or a failure of the gingival tissue to adequately recede to the proper level relative to the cementoenamel
- The compensatory eruption of the maxillary teeth with the concomitant coronal migration of the gingival margins
Treatment for excessive gingival display depends on the diagnosis and cause of the excessive gingival display. Additionally, treatment depends on the perception and expectation of the patient. Some patients may find their gums aesthetically-pleasing and may not wish to seek out treatment.
Nevertheless, there are various options available to address the issue if one wishes. This includes the control or the modification of the particular aspects of facial growth, maxillary incisor intrusion by orthodontic means, surgical maxillary impaction, gingivectomy and apically repositioned flap, and the restriction of the upper lip elevation when smiling like Botox.