A “gummy smile” is the colloquial term used to describe an excessive exposure of the gums when you smile. In medical terms this is known as “excessive gingival display” and is usually diagnosed when more than 2mm of the gum is exposed when smiling. It is a common problem that is generally caused by overgrowth of the gum tissue, but the positioning of the jaw and the way the jaw developed can also play a part. People with a gummy smile may feel that their gums look too big or prominent when they smile. It can also impact the aesthetics of the smile in other ways by making the smile look uneven or wonky and by making the teeth appear disproportionately smaller than they are. A gummy smile often goes hand-in-hand with a high lip line and short upper lip too.