Drooling

What Is Drooling?

Drooling is the unintentional loss of saliva from the mouth.

Drooling is a normal phenomenon in children prior to the development of oral muscular control at age 18-24 months. Many children lose control of saliva and drool as they are developing control of gross motor and fine motor movements.

Control of drooling requires developed oral sensation and muscle movements to swallow automatically while focusing attention on new skills. The development of stability is a major component of normal development, and stability of the head, neck and shoulder girdle is prerequisite to fine motor control of the mouth. 

Whilst drooling is a normal occurrence in young children, persistence of drooling beyond four years of age is not considered normal. If a child continues to drool beyond four years old it may be a result of very low muscle tone or the child may have a physical disability or developmental delay. Individuals with a disability may have reduced muscle control. When this control is lacking, drooling is likely to occur.

In an Australian study of people with complex communication needs in a variety of diagnostic groups, 29% were found to experience issues relating to saliva control. Inadequate saliva control is seen in between 10% and 37% of children with Cerebral Palsy.

Causes Of Drooling

Drooling can be a result of hypersecretion (increased secretion) of saliva but more commonly occurs as a result of impaired oral muscle control.

Drooling often occurs as a result of a decrease in the frequency of spontaneous swallowing, and/or a reduction in the sensory awareness necessary for the swallowing.

Swallowing

Swallowing occurs when we eat or drink and when we swallow saliva.

The act of swallowing involves a complex and coordinated sequence of movements. Swallowing requires lip closure, jaw stability and controlled tongue movements. There are three stages in the swallowing of food process: the oral phase, pharyngeal phase and oesophageal phase. The phase most relevant to saliva control is the Oral Phase.

Oral Phase

The oral phase occurs in the mouth and is a voluntary process. During the oral phase the food is chewed in the mouth and prepared before it is swallowed. To do this, the person must be able to move the jaw up and down to chew the food. It is also important to be able to bring the lips together in order to keep the food or fluid from spilling out of the mouth. Control of the tongue is also required to clear food from the teeth and assist in preparing the food for swallowing.

The tip of the tongue is then raised and as the tongue contracts, the food or fluid is pushed towards the back of the throat.

This phase also occurs when we swallow saliva. Every few minutes saliva collects in the mouth and provides a pressure cue needed to trigger a swallow. The same process takes place with the tongue contracting and pushing the saliva to the back of the throat.

Swallowing can contribute to drooling if the person does not swallow frequently enough or if the swallowing is not effective. Delayed or limited oral skills can also influence the development of tongue elevation during the swallow.

Overproduction of saliva and thin, watery saliva

An overproduction of saliva is most often not the cause for drooling. The causes for drooling are varied, but are usually related to decreased control or swallowing of saliva while in the oral cavity. An overproduction of saliva leads to the mouth being constantly bathe with saliva, and may require the individual to frequently spit or swallow excess saliva. It will only result in drooling if the patient's saliva control is also inadequate.

The following are causes for an increase in saliva production, often resulting in excess watery saliva bathing the mouth:

• Medications - In particular, cholinergic drugs can cause an overproduction of saliva. Discuss with your doctor if you believe your medication is causing hyper salivation.
• Toxins - Poisoning from certain toxins can result in hypersalivation as one of the side affects. Your doctor should be consulted immediately if you believe you have ingested any toxins.
• Lesions or infections in the oral cavity - An infection of the mucosal lining of the mouth is referred to as stomatitis. Stomatitis can result from infectious agents (bacteria, viruses, fungi), which can develop when poor oral hygiene is maintained. Physical injury or chemotherapy can also result in lesions and infections in the mouth. Your dentist or doctor can be consulted if you are experiencing any infection in the oral cavity.
• Gastrointestinal causes - Ailments such as reflux, liver disease, gastric ulcers, pancreatitis or gastric distention or irritation can result in an increase of saliva production. If you are experiencing hypersalivation as a symptom of gastrointestinal complaints, please consult your doctor.
• During pregnancy - Hypersalivation is one of the lesser known symptoms of pregnancy. Overproduction of saliva occurs particularly during early stages of pregnancy, when morning sickness is occurring.
• Vegetable agents - Excessive starch intake, tobacco, jaborandi and muscarin are the most common vegetable products that may result in hypersalivation. Generally, the action of these agents is not long lasting. If you have any concerns regarding hypersalivation after ingestion of vegetable agents, please see your doctor.

For a full list of causes view the Family Practice Notebook.

Where hypersalivation is secondary to another condition, an excess amount of saliva is not usually severely limiting or even permanent. The treatment of the primary cause is often the cure for the hypersalivation. Talk to your doctor if you are at all concerned about the cause of hypersalivation and the treatment. 

Social Implications of Drooling

Drooling or dry mouth are not dangerous; they do not cause life threatening medical complications. But drooling and dry mouth can cause problems of both the emotional and physical kind. For some individuals this can be quite serious and dilapidating, ranging from mild embarrassment to complete social alienation and adverse reactions from peers.

There are several implications of drooling which impact upon patients socially every day, causing embarrassment, social isolation and alienation for both the individual and their family:

• The constant exposure of skin to saliva can cause a rash around the mouth, chin or lips, chapping of lips and infections around the mouth. Not only does it cause discomfort or even pain, but the sores are viewed as unsightly by the wider community.
• Chronically irritated facial skin may even develop scars, adding to social exclusion.
• Clothing requires several changes per day, which can become very laborious for the family or carers. They may opt for the patient to wear a bib, which results in stigmatization in the wider community.
• Drooling may limit the use of electronic communication devices or teaching materials, as they can become wet and damaged.
• Drool may also stain, books, furniture, carpet etc. This can not only lead to negative community feelings, but also difficulty with employment.
• The embarrassment felt by the patient may result in their limit of interaction with peers, causing social isolation.
• Many drooling patients have poor oro-motor control and have difficulty transporting food and saliva to the back of the mouth impacting on their ability to eat.
• Smell of stale saliva.