By Dr Ng Chee Hon

Q: I'm a young woman and I drool every time I am asleep. It can be embarrassing, so I don't participate in sleepovers or camps with my friends.

Why does this happen and what can I do to prevent it? I also wear dentures which I remove at night.

A: Hypersalivation or drooling is defined as salivation beyond the margins of the lips. This condition, normal in infants, usually stops by 15 to 18 months of age. The complications of drooling range from mild and inconvenient symptoms to severe problems.

Physical complications include chapping around the mouth and broken skin with secondary infections, dehydration and bad breath.

Generally the causes of drooling can be divided into neuromuscular and sensory dysfunction, hypersecretion and anatomy causes.

Treatment is directed at the underlying cause.

Neuromuscular and sensory dysfunction can result in decreased clearance of saliva. In adults, Parkinson's disease is the most common cause.

Excessive secretion is caused by inflammation such as teething, dental caries and infections. Other causes include side effects from drugs like tranquilisers and anti-convulsants, pregnancy, excessive starch intake, intoxication and rabies infection. Anatomy causes such as a large tongue, crowded teeth, poor lip closure and enlarged adenoids and tonsils may predispose a patient to salivary spill.

Treatment ranges from simple observation, postural changes, biofeedback and orthodontics to more radical measures such as medication, radiation and surgery.

In your situation, do seek an initial opinion from your general dental practitioner to eliminate dental causes and for a restorative option for the missing teeth.

You can also institute self-help measures like the frequent use of mouthwash and reduction of food containing starch prior to bedtime. Medications such as glycopyrrolate and scopolamine patch can be effective when engaging in outdoor activities. However there are side effects to these agents like constipation, urinary retention, blurred vision and irritability.

For a long-term solution, you can consider the injection of botulinium toxin into the salivary glands. Surgery including salivary gland excision and salivary duct ligation may be performed if all else fails.

Dr Ng Chee Hon is a consultant oral and maxillofacial surgeon at Raffles Hospital.

This story was first published in Mind Your Body, The Straits Times, on Dec 18, 2008.