A painless cyst that appears on the inside of the lip is known as a mucocele, or a mucous retention cyst. Mucoceles are a harmless, common condition resulting from the collection of clear fluid on the interior surface of the lip. Though these cysts, also known as mucous cysts, normally heal on their own, recurrent mucoceles have the potential to permanently scar the area on which they form. In some cases, certain types of mucocele formation may result in complications requiring medical attention.
Individuals who habitually suck their inner lip between their teeth often experience the formation of a mucocele. The pressure placed on the membranes of the inner lip causes the collection of clear liquid within a thin sac, ultimately forming a cyst. It has been suggested these cysts result from the ductal obstruction or rupture of the salivary glands. The small cysts that form are harmless, but can be quite annoying. Those who have had their tongue or lebret pierced may experience the formation of a cyst in the immediate area of the piercing.
A diagnosis of a mucocele may be confirmed with a visual examination of the affected area. In cases where the cyst causes discomfort, a doctor visit may be necessary. Continued trauma to the affected area can result in delayed healing, and potentially cause the enlargement of the cyst due to the collection of additional fluid. Most often, when the affected area is left alone, the cyst will independently rupture and heal.
To relieve discomfort, it may be necessary to open the cyst to allow drainage and promote healing. An opening of the cyst should be conducted in a doctor's office and performed by a trained health care professional to reduce the risk of infection. In cases where infection does develop, antibiotics are usually administered. The persistent recurrence of a cyst may result in the formation of a permanent, hard nodule on the affected area.
Though most commonly found on the lips, these cysts may form anywhere within the oral cavity. A mucous cyst which forms on the gum, known as an epulis, generally results from repeated trauma to the affected area, as found with individuals who wear dentures. A cyst that forms on the bottom, or floor, of the mouth is referred to as a ranula. Trauma, tissue damage, or ductal obstruction of the salivary glands is usually the genesis of a ranula's formation. Unlike other mucoceles, epulis and ranula cysts frequently require surgical removal to prevent further discomfort and complication.