In fact, closed mouth is also called closed acne, and most of this condition will slowly disappear on its own. The formation of closed acne is actually due to the fact that the cortical fat secreted by the sebaceous glands cannot be effectively discharged from the surface of the skin, and thus deposited in the ducts of the sebaceous glands; after being concentrated or mixed with other shed cells, closed acne, also called whitehead acne, is formed. Closed acne is mostly related to improper diet, improper skin hygiene, excessive oil secretion and other factors; after it occurs, you can adjust your diet and lifestyle appropriately; drink more water, eat more vitamin-rich foods, rest on time and avoid staying up late. In most cases, this condition can subside on its own; if it does not subside for a long time, it can be treated with some medications, usually with topical adapalene gel. The medication should be used under doctor’s instruction. If there is any abnormality, you should go to the hospital for examination in time.