Skin Care Education

Gummy Smile

A smile in which more gum tissue than is proportionate is visible above the upper front teeth. Also known clinically as excessive gingival display. Can result from several different underlying causes.

What Is a Gummy Smile?

A gummy smile, known in clinical terminology as excessive gingival display, refers to a smile in which the amount of gum tissue visible above the upper front teeth is considered disproportionate to the overall balance of the smile. While some gum visibility is entirely normal and present in many attractive smiles, a gummy smile is generally defined clinically as one in which four millimetres or more of gum tissue is exposed above the upper incisors during a full smile.

The visual impression of a gummy smile arises from the ratio of visible gum to visible tooth. When this ratio is high, the gum tissue dominates the upper smile zone in a way that can draw attention and, for some individuals, create self-consciousness about smiling openly. The condition is entirely benign from a medical standpoint and has no association with dental or general health problems. Its significance is purely cosmetic.

Importantly, a gummy smile is not a single condition with a single cause. Several different anatomical factors can produce the appearance of excessive gingival display, and these factors require different approaches to address. Identifying which underlying cause is responsible is the essential first step before any management is considered, as an approach suited to one cause may be ineffective or inappropriate for another.

Types of Gummy Smile

Hypermobile upper lip (muscular): the most common presentation encountered in aesthetic practice. The upper lip elevator muscles, particularly the levator labii superioris and levator labii superioris alaeque nasi, contract with greater than average force during smiling, pulling the upper lip higher than normal and exposing more gum. The jaw and teeth are structurally normal. This type is a muscular functional characteristic rather than a structural anatomical difference.
Vertical maxillary excess (skeletal): caused by a jaw bone that is vertically longer than average. The greater vertical height of the upper jaw means that more gum is positioned within the smile zone when the mouth opens to a normal smile position. This type has a skeletal basis and generally requires dental or surgical assessment for significant correction.
Altered passive eruption (dental): occurs when the gums have not receded to their normal position following tooth eruption, leaving the crown of the tooth partially covered. The teeth appear shorter than they actually are, and the ratio of gum to tooth is altered. This is a dental condition managed within dentistry.
Short upper lip: a naturally shorter upper lip provides less coverage of the gum tissue in its resting and smiling positions. Even with normal muscle activity and normal jaw and tooth proportions, a shorter lip may reveal more gum when smiling.
Combination: some individuals present with more than one contributing factor simultaneously, such as a hypermobile upper lip in conjunction with a shorter-than-average upper lip length.

Causes and Contributing Factors

Factor	Description
Hyperactive upper lip elevator muscles	In the most common aesthetic presentation, the muscles responsible for lifting the upper lip during smiling contract with greater force or to a greater degree than average. This pulls the upper lip higher, exposing more gum tissue above the teeth. The muscular overactivity is the primary driver in this type, independent of jaw or tooth anatomy.
Vertical maxillary excess	When the upper jaw bone is longer in the vertical dimension than average, more gum tissue sits within the zone exposed during smiling. This skeletal characteristic is present from skeletal development and is not related to muscle activity or dental position.
Altered passive eruption	In normal dental development, the gum tissue recedes to a predictable position on the tooth crown as the tooth erupts. When this recession is incomplete, excess gum covers part of the crown, making teeth appear shorter and the gum margin appear higher. This is a dental developmental variation.
Lip length and anatomy	The natural length of the upper lip is an anatomical characteristic that varies between individuals. A shorter upper lip covers less of the gum tissue in both the resting and smiling positions, contributing to greater gingival visibility regardless of muscle activity or jaw anatomy.
Genetics	The structural characteristics of the jaw, the proportions of the teeth and gums, the anatomy of the lips, and the activity level of the upper lip muscles all have significant hereditary components. Gummy smiles frequently run in families.

Frequently Asked Questions: Gummy Smile

No. A gummy smile is a cosmetic characteristic with no association with dental disease, oral health problems, or any general health condition. The gum tissue itself is entirely healthy. The concern is purely aesthetic and relates to the proportions of the smile rather than to any functional or health-related issue.

Because different causes require fundamentally different approaches. A gummy smile caused by hyperactive upper lip muscles is a muscular functional issue that can be addressed through relaxation of those muscles. A gummy smile caused by vertical maxillary excess is a skeletal structural issue that requires a different type of assessment and management. A gummy smile caused by altered passive eruption is a dental issue addressed within dentistry. Applying an approach designed for one cause to a gummy smile with a different underlying cause will typically produce no improvement or an inappropriate result.

There is a natural spectrum of gum visibility in smiling, and what is considered aesthetically balanced varies with cultural context and individual preference. As a general clinical reference point, one to two millimetres of gum visibility above the upper incisors during a full smile is widely considered within a normal aesthetic range. Visibility of four millimetres or more is the threshold typically used clinically to define excessive gingival display, though individual perception and concern varies considerably and there is no single universally correct measurement.

Yes. Gummy smiles are somewhat more prevalent in women than men, partly because female facial anatomy tends toward a slightly shorter upper lip and partly because of differences in the typical activity level of the upper lip elevator muscles. Vertical maxillary excess, one of the skeletal causes, also tends to be more pronounced in women. The condition is also more common in younger individuals, as the upper lip tends to lengthen slightly with age, naturally reducing gum visibility over time in those whose gummy smile has a lip length component.