Gummy Smile

A gummy smile, clinically referred to as excessive gingival display, is defined as more than about three millimetres of gum showing above the upper teeth when a person smiles fully. It is a surprisingly common aesthetic concern, affecting roughly one in ten adults to some degree, and the perceived severity varies with cultural expectations and individual lip and tooth proportions. The underlying anatomy can involve any of several contributing factors: an overactive upper lip elevator muscle (the levator labii superioris alaeque nasi and the levator labii superioris, which together lift the central upper lip), a short or hyperactive upper lip, dentoalveolar extrusion (teeth that have erupted too far), excessive gingival tissue (gummy overgrowth that has not receded with age), and in some cases vertical maxillary excess, a skeletal problem where the upper jaw is longer than average. A proper assessment distinguishes between these causes because the treatment differs substantially. Aesthetic injectable treatment is suitable only for cases where the primary driver is lip elevator hyperactivity or a short upper lip. Dental extrusion is managed by orthodontics or crown lengthening. Gingival overgrowth is managed by periodontal gingivoplasty. Skeletal vertical maxillary excess is a maxillofacial surgical indication, typically Le Fort I impaction, and injectable treatment will not resolve it. For the muscular form, small doses of botulinum toxin are injected into the lip elevator muscles, usually at a point known as the Yonsei point, near where the levator labii, levator alaeque nasi and zygomaticus minor converge. Low, carefully titrated doses reduce the upward pull on the central upper lip without impairing smile symmetry or speech. Effects develop over one to two weeks and last about three to four months. Over-correction can cause a flat, asymmetric smile or difficulty pronouncing certain sounds, so restraint in dosing and a staged approach are essential. Some clinicians also use very small amounts of hyaluronic-acid filler in the upper lip to lengthen the vertical height of the lip slightly, reducing the gum show without affecting the muscle. Patients with previous orthognathic surgery, pronounced asymmetry, or a history of lip or gum surgery should be assessed alongside their dentist or maxillofacial surgeon before injectable treatment.