Drooling (Sialorrhea)

Updated: Mar 23, 2022
  • Author: Neeraj N Mathur, MBBS, MS, DNB, MAMS, FAMS; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Practice Essentials

Drooling (sialorrhea) is the unintentional loss of saliva from the mouth. The term drooling commonly refers to anterior drooling and should be distinguished from posterior drooling, in which saliva spills over the tongue through the faucial isthmus. Drooling is a significant disability for a large number of pediatric and adult patients with cerebral palsy and for a smaller number of patients with other types of neurologic or cognitive impairment.

The following image demonstrates bilateral submandibular duct transposition, which is the most commonly surgical procedure performed for drooling.

Floor of mouth, as seen after bilateral submandibu Floor of mouth, as seen after bilateral submandibular duct transposition. Image courtesy of Dr Neeraj N Mathur.

Drooling is a normal phenomenon in children prior to the development of oral neuromuscular control at age 18-24 months. However, drooling after age 4 years is uniformly considered abnormal. Children with neurologic impairment may be slow to mature their oral neuromuscular control and may continue to improve their control until approximately age 6 years, which prompts physicians to delay any aggressive intervention until that time.


Laboratory studies include the following:

  • Salivary flow rate (mL/min) - Increase in weight of dental rolls/time of collection
  • Drooling Quotient - 40 observations in 10 minutes (every 15 minutes)
  • Teacher Drooling Scale - 1-5

Imaging studies include the following:

  • Lateral neck film - Adenoid hypertrophy can be confirmed if the patient has a history of nasal obstruction; complete the  adenoidectomy prior to further surgical intervention to neutralize the effects of mouth breathing on drooling.
  • Modified barium swallow - Some authors recommend performing this study to help rule out the contraindications to surgical therapy, including esophageal motility disorders, esophageal spasm, and aspiration
  • Radiosialography - For some authors and for research purposes, these scans using radioisotope are useful for evaluating the secretory function of the salivary gland when assessing the success of surgical therapy

Additional tests include the following:

  • Audiogram - Perform this study on patients being considered for tympanic neurectomy or chorda tympani nerve section, because unilateral hearing impairment is a contraindication (owing to the risk of hearing loss associated with the procedures)
  • Flexible nasopharyngoscopy - This is an alternative method of assessing the amount of adenoid tissue if the patient has history findings suggestive of nasal obstruction


Medical management is directed towards correcting oral motor dysfunction and decreasing the secretory volume of salivary glands. It can include use of the following:

  • Oral motor training
  • Behavioral therapy
  • Pharmacologic therapy - Anticholinergics, botulinum toxin
  • Radiotherapy

Three surgical approaches by an otologist can help to decrease salivary flow, including removal of the salivary glands, ligation of the salivary ducts, and sectioning of the nerves in the middle ear, which are responsible for salivary production.

Procedures to redirect the salivary flow have the positive effect of preserving salivary production and taste. Bilateral transposition of the submandibular ducts is the most commonly performed surgical procedure for drooling in many centers.



Because of the associated cerebral palsy, drooling causes functional, social, psychological, and clinical burdens on patients, their families, and caregivers.

Patients who drool often experience repeated perioral skin breakdown and infections. Clothing and bibs become soiled and need frequent changing, which can become very laborious and limit the family's ability to be active and out of the home. In addition, teaching materials and communicative devices may become wet and damaged, impairing educational efforts. In severe cases of drooling, dehydration may even become a problem. Social embarrassment may make it difficult for patients who drool to interact with their peers and can lead to isolation.

Posterior drooling, however, causes congested breathing, coughing, gagging, vomiting, and, at times, aspiration into the trachea that results in recurrent pneumonia. [1]

Because the lifespan of cerebral palsy patients is often shortened, more than 85% of patients with problems controlling drooling are younger than 21 years.




The actual prevalence rate for patients who drool is unknown. However, 0.5-0.7% of all children born are diagnosed with cerebral palsy. From 10-37% of patients with cerebral palsy have been reported to have difficulty with drooling because of neurologic impairment. Reportedly, 10% of Swedish, 37% of Belgian, and 13% of Indian children with cerebral palsy have severe drooling. However, this is not an affliction that is particular to any specific ethnic background. Most of the patients requiring help for drooling belong to this group.



Drooling may be a result of hypersecretion (primary sialorrhea) of the salivary glands but is more commonly due to impaired neuromuscular control with dysfunctional voluntary oral motor activity that leads to an overflow of saliva from the mouth (secondary sialorrhea). Patients often have inefficient and infrequent swallowing, which further compounds the problem. Furthermore, problems with positioning due to poor head control and decreased neck strength magnify the effects. An enlarged tongue or tongue thrusting with poor control can contribute to the problem of drooling. Finally, dental caries and infection and diseased gingival tissues with gingivitis can markedly increase drooling.

The salivary glands secrete an average of 1-1.5 L of saliva per day. The 3 groups of major paired salivary glands, the submandibular, sublingual, and parotid glands, along with the minor salivary glands located throughout the surface of the palate, tongue, and oral mucosa, secrete saliva. The submandibular gland produces 70% of resting secretions. The 20% from the parotid glands is a result of external stimuli such as food. The remaining 10% of saliva secreted is from the sublingual and remaining minor salivary glands. Saliva serves many functions. It protects the teeth and gingival tissues from infection, lubricates the oral mucosa to aid in swallowing and speech, deters foul breath by cleansing the oral cavity, and promotes digestion by breaking down proteins and carbohydrates with amylase.

The secretory control of the salivary glands is mostly parasympathetic. Innervation of the parotid gland is from the salivary nucleus via the glossopharyngeal nerve, the tympanic plexus in the middle ear, the otic ganglion, and the auriculotemporal nerve. The submandibular and sublingual glands receive fibers carried by the facial nerve and chorda tympani, which originate in the superior salivatory nucleus.

Hypersecretion is a rare cause of drooling. Most often, this occurs as an adverse effect of medications such as some tranquilizers, anticonvulsants, and anticholinesterases that increase activity at the muscarinic receptors of the secretomotor pathway and result in hypersecretion.

Any impairment of the oral phase of deglutition secondary to neuromuscular disorders, trauma, surgical resection, or facial nerve paralysis can result in spillage of saliva from the oral cavity. Most patients who drool have impaired oral neuromuscular control due to cerebral palsy or severe mental retardation.




A thorough history is invaluable prior to treatment. Make an assessment of the severity and frequency of drooling, and inquire about the effect on the quality of life for the patient and family. Importantly, identify factors contributing to drooling. Caregivers or parents can assist in assessing the characteristics of drooling, such as peak time of day, changes in volume with specific activities, consistency of saliva (ie, thick, mucinous, watery), and the frequency of drooling.

Quantitative measurements can be difficult, but classification schemes for drooling have been developed to give a general idea of the magnitude of the problem. Multiple classification schemes have been used by different authors to report the severity of drooling.

The severity of drooling can be classified with the following scale:

  • Dry - Never drools

  • Mild - Only lips wet

  • Moderate - Lips and chin wet

  • Severe - Clothing soiled

  • Profuse - Clothing, hands, and tray moist and wet

The frequency of drooling can be quantitated based on the following scale:

  • Never drools

  • Occasional drooling - Not every day

  • Frequent drooling - Every day

  • Constant drooling

These types of classifications can be helpful for guiding treatment decisions and for preoperative and postoperative comparisons to determine the outcome of surgery. They can also be helpful for reporting purposes to compare results of techniques between institutions.

Some specific points to address when assessing the magnitude of the problem with caregivers include the following:

  • Number of bib or clothing changes per day

  • Difficulties with keyboards or other communication devices

  • Severity of perioral skin maceration and infections.

The system used by Wilkie and Brody to classify the results of drooling procedures is as follows:

  • Excellent - Normal salivary control

  • Good - Slight loss of saliva with or without dried froth on the lips

  • Fair - Improved, but with significant residual saliva loss or with thickened, offensive, brown, gummy froth

  • Poor - Failure to control or too dry

Other clinical factors that could contribute to drooling and spillage of oral contents should be explored while taking the patient's history. Nasal obstruction with chronic mouth breathing can exacerbate drooling. The most common cause of obstruction is adenoid hypertrophy, but consider anterior obstruction of the nose due to other causes, such as allergic rhinitis. Malocclusion, gingivitis, and dental caries can contribute to drooling and should be addressed by a pediatric dentist at the outset of the evaluation.

Physical examination

Perform a thorough head and neck examination. Give special consideration to those anatomic factors that could contribute to or exacerbate drooling so that these issues can be addressed prior to surgical intervention. Some key points to evaluate during the physical examination include the following:

  • Head position and control

  • Condition of perioral skin

  • Tongue size and control and the presence of thrusting behaviors

  • Tonsil and adenoid size

  • Occlusion: Malocclusion, particularly an open bite deformity, is a common finding in patients with cerebral palsy. This can make proper oral hygiene very difficult. Open bite deformities can prohibit closing of the mouth and can mimic nasal obstruction in these patients.

  • Dentition: Caries may be noted.

  • Gingival tissues

  • Mandible and palatal position

  • Gag reflex and intraoral tactile sensitivity

  • Presence of mouth breathing

  • Nasal obstruction and the appearance of tissues upon anterior rhinoscopy

  • Swallowing efficiency: Determine this by observation, barium swallow, or fiberoptic endoscopic evaluation of swallowing.

  • Neurologic examination: Pay particular attention to cranial nerve examination findings.



Indications for surgery include (1) persistent drooling following at least 6 months of conservative therapy and (2) moderate to profuse drooling in a patient whose cognitive function precludes participation with conservative oral and physical therapy.


Relevant Anatomy

Parasympathetic innervation of the parotid gland is from the inferior salivary nucleus via the glossopharyngeal nerve, the tympanic plexus on the medial wall of the middle ear, the lesser superficial petrosal nerve, the otic ganglion, and the auriculotemporal nerve. The submandibular and sublingual glands are innervated by fibers from the superior salivary nucleus via the facial nerve, chorda tympani in the middle ear, lingual nerve, and submandibular ganglion.



1. Patients at high risk for surgery because of other medical concerns.

2. Tympanic neurectomy and chorda tympani nerve sections are contraindicated in patients with unilateral hearing loss because of the small risk of hearing loss associated with these procedures.

3. Posterior rerouting of the submandibular or parotid ducts is controversial in patients who have difficulties with chronic aspiration due to their neurologic status. Associated conditions may include esophageal motility disorders, esophageal spasm, or aspiration. Some authors believe this procedure puts the patient at increased risk of aspiration because of the increased burden of secretions in the hypopharynx. Other authors have demonstrated no increased difficulty with aspiration in this patient population.

4. In patients with athetoid disorders with constant tongue thrusting, surgical procedures to correct drooling may result in an unpleasant, thick, discolored, malodorous residue being deposited on the teeth and lips. This may prove to be more offensive than the constant, watery drooling.