Drooling is a group of syndromes in which saliva spills out of the corners of the mouth or swallows and exhales frequently and uncomfortably due to high salivary gland secretion or swallowing disorders. In layman’s terms, it means excessive drooling. Physiological salivation is common in infants and usually ends on its own at 15 to 18 months of age. Pathological salivation is often caused by neuromuscular dysfunction, increased salivary secretion and sensory disorders, and anatomical abnormalities. Among them, neuromuscular dysfunction is the most important factor. Cerebral palsy is the most common cause of salivation in children, and Parkinson’s disease is the most common cause of salivation in the elderly. The current treatment for drooling disorder mainly includes the following: 1. Oral drugs: mainly M-choline receptor blockers, such as atropine, benzodiazepine and scopolamine. However, the side effects on the whole body are large and the effect is limited. 2.Local injection of botulinum toxin into salivary glands. 3.Surgical treatment: including removal of large salivary glands, parotid and submandibular gland duct ligation or transposition, parasympathectomy. Are there any side effects after treatment with botulinum toxin for patients with salivary disorders? There are few side effects. Occasionally, there are reactions such as dry mouth, weakness of the occlusal muscles, and localized swelling and pain. If the injection is inappropriate, side effects such as dysphagia and dysarthria have also been reported. However, all of these adverse reactions are transient and can resolve on their own. The current method of botulinum toxin injection in salivary glands is to select local injection in parotid and submandibular glands. For mild to moderate salivation, a single intraparotid botulinum toxin injection can be chosen, while for severe cases, both parotid and submandibular gland injections can be chosen. Ultrasound-guided injections are recommended. Treatment is easy and quick. Transient: “Transient” refers to a clinical symptom or sign that occurs once in a short period of time, often with an obvious trigger, such as after eating certain foods, taking certain medications, receiving certain clinical treatments, or other factors that affect the body. As the trigger is removed, the symptom or sign disappears quickly. The term “transient” literally means that it passes in a flash, such as a transient headache, which is often overlooked. In clinical practice, “transient irritation” and “transient diarrhea” are usually seen.