In the oral and maxillofacial surgery clinic, we often see anxious parents with their children, telling the doctor that their child has a blister inside the lip, which is big and small, small and big again, repeatedly, and often bitten while eating and talking. This is usually a case of a small salivary gland mucus cyst. Broadly speaking, salivary gland mucous cysts include minor salivary gland mucous cysts and sublingual gland cysts, which are the more common salivary adenoma-like lesions. A large number of minor salivary glands exist beneath the oral mucosa, and these minor salivary glands usually secrete small amounts of saliva to keep the oral mucosa moist. When these minor salivary glands rupture, leakage into the interstitial space, or partial obstruction of the ductal system, or bending of the ductal system, mucus outflow is blocked, causing mucus retention. Therefore, they often appear clinically as small oral masses. Small salivary gland mucous cysts are found on the ventral side of the lower lip and tongue, because the submucosal glands are often injured by the friction of the lower front teeth and by the conscious or unconscious action of biting the lower lip. The cysts are located in the submucosa, and the surface is only covered with a thin layer of mucosa, so they appear as translucent, light blue blisters, resembling blisters. Most of them are soybean to cherry size, soft and elastic in texture. The cysts are easily ruptured by bites and flow out clear egg-white like sticky liquid, and the cysts disappear. After the rupture heals, it is filled with mucus and forms cysts again. Repeated ruptures no longer have the clinical features of cysts, but instead show thicker white scar-like protrusions with reduced cyst transparency. Therefore, treatment for minor salivary gland mucous cysts can be conservative or surgical. The principle of conservative treatment is to use drugs to destroy the salivary epithelial cells so that they lose their secretory function and no longer form cysts. However, the efficacy of conservative treatment is not exact and there are often recurrences, and the most common treatment method is still surgical excision. The core of surgical treatment is the removal of the regional minor salivary gland including the mass so that it no longer secretes mucus and avoids the formation of cysts. Most of the minor salivary gland mucous cysts are formed due to bad habits such as rubbing or lip biting, so prevention of their occurrence requires first of all the cessation of bad habits. Of course, in pediatric patients there are often cases of recurrence even after surgical treatment. The reason for this is that, on the one hand, the small salivary glands that cause mucus retention are not removed during surgery. On the other hand, it may be due to the formation of new mucous cysts in the minor salivary glands due to mucous retention in the previously normal minor salivary glands as a result of unabated habits.