The gums, or gingivae, are made up of the soft, mucosal tissue that lies over the upper and lower jaws inside the mouth. They surround the teeth of the upper and lower jaws and provide a protective seal for the teeth. The gums are securely bound to the bone that lies beneath them, helping them remain resilient against the friction of drinking and eating, unlike the other soft tissues that line the mouth inside the lips and cheeks. When they are healthy, the gums help protect the tissues that are deeper in the mouth. One of the first indications of ill health of the gums is often a change in color. In lighter-skinned people, the gums are usually a light pink color, and they may be darker in people with more melanin pigmentation; therefore, the color of unhealthy gums is measured in relation to their individual ideal color. Inflammation is also indicated by swelling and increased predisposition to bleeding and is often due to the accumulation of dental bacteria. The health of the gums can both reflect and affect a person’s overall health. When gum tissue is unhealthy, it can allow disease to enter the deeper tissues of the mouth, which can lead to the loss of the teeth over the long term.

The gums are categorized into three anatomical categories: marginal, attached, and interdental. Marginal gums are the gums that surround the teeth, in the scallop shape that characterizes the gumline. Marginal gums are more translucent than the other types of gingiva, though they otherwise have similar visual characteristics. The tissue of the marginal gums is not connected to the underlying tooth surface and is stabilized only by gingival fibers; there is no bone supporting them. The free gingival crest demarcates the outermost part of the marginal gingiva. The attached gums are bound to the underlying alveolar bone and are a continuation of the marginal gum. Sometimes, the attached gum appears to have a slight bumpy texture, referred to as surface stippling. The amount of attached gum tissue varies depending on its location in the mouth, though a certain amount of attached gum is necessary to maintain the stability of the roots of the teeth. The interdental gums lie between the teeth. They are usually shaped like the notch in between two mountains, in a shape that is called a “col.” The size of the col varies based on the spacing and shape of the teeth and may extend fully between the facial and lingual sides of the jaw, with no interruption by contact between teeth.

Discolored gums may indicate inflammation or pathology. Smoking and the use of drugs may also cause discoloration of the gums. Variations in the color healthy gums may also appear, depending on the thickness of the tissue, the amount of blood that flows to the tissue, certain medications, and natural variations in pigmentation. If these natural discolorations are unwanted, they can be addressed in a cosmetic dental procedure called gum depigmentation. In addition to color, gum pathologies can be indicated by the shape of the tissue in relation to the teeth; the texture of the gums; and their reaction to irritation, such as during brushing or dental probing. An overgrowth of bacterial plaque in the mouth, due to inadequate oral hygiene, is one of the primary causes of gum disease and also one of the most easily remedied with regular, proper oral care.