Mucoceles are common lesions of the oral mucous membrane involving minor salivary gland tissue. The lower lip is the site most frequently affected, the remainder occur in the cheek, palate, floor of the mouth, tongue, and retromolar fossa. The upper lip is rarely affected.
Mucoceles occur most often in children and young adults.
The mucocele, a mucus accumulation phenomenon of the salivary gland, is a common lesion of the oral cavity.
In the past it was believed that oral mucoceles arise from obstruction of an excretory duct, which caused back pressure of mucus and the formation of an epithelial-lined cyst. It is now, however, generally accepted that most mucoceles are caused by trauma-injury or severing of an excretory duct and subsequent escape of mucus into the adjacent tissue.
Histopathologically, there are two types of mucoceles:
1) Mucous extravasation cyst, generally regarded as being of traumatic origin, such as lip biting.
2) Mucous retention cyst result from obstruction of the duct of a minor or accessory gland.