Botulinum Toxin:A new and unlikely hero in the battle against drooling

 Botulinum toxin, more famous in its cosmetic avatar 'Botox ' has been a cosmetologist's delight. The toxin when injected in small amounts causes muscular rigidity thereby countering the effects of ageing. However research over the past decade has seen developments that could alter the management of drooling of sali


What is Drooling?
 Drooling is basically the escape of excess saliva from the mouth. Drooling is seen commonly in normal infants, it usually subsides by 15-18 months of age as a consequence of physiological maturity of oro-facial motor function.Although drooling may, in some rare cases, persist in a normal child, its presence beyond the age of 4 years must be considered abnormal. Some investigators believe that individuals may have both an increased salivation and decreased or ineffective swallowing  , while other studies and reviews of literature show that drooling is mainly due to a swallowing defect caused by poor neuromuscular coordination. Drooling of saliva is seen in a wide spectrum of disorders most of which have poor neuromuscular neuromuscular coordination such as Cerebral Palsy, Parkinsons disease or Amyotrophic lateral sclerosis (ALS).




 ^{Why Treat Drooling ?}

<sup>Drooling of saliva has been shown to cause both psychological problems and problems such as irritation or maceration of the skin, increased perioral infection, a foul smelling odor and dehydration due to fluid and nutrient loss. Drooling can also cause impairment of speech and masticatory function and leads to an increased chance of peri-oral infection especially Candida albicans. Severe drooling may also result in aspiration pneumonia. Traditional methods of controlling drooling such as Surgically repositioning salivary gland ducts or drugs to control drooling have often lead to serious side effects such as dryness of mouth, severe dental caries, dysphagia or burning mouth. Methods that do not reduce salivary flow such as biofeedback and appliances while promising have not been tested on a large scale.


What is Botulinim Toxin ?
Botulinim toxin or neurobotulinum toxin serotype A (NBS)is a toxin produced by the Gram negative anaerobic  bacteria Clostriduim botulinum. It's action is based on the inhibition of acetylcholine release at the pre-synaptic level. While the resultant loss of neuronal tone causes muscle flacidity and is responsible for the disappearance of wrinkles it's actions on the salivary glands is quite different.

Botulinum toxin in the treatment of drooling</sup>
The cholinergic system stimulates the production of saliva. Systemic Anticholinergic drugs such as atropine have long been used to control excessive salivation for short periods of time such as during dental treatment. However the use of these drugs have a systemic component thus inhibiting their use in long term therapy. Botulinum toxin by means of it's anticholinergic action inhibits the salivary flow. However when injected into the the desired site it has an almost completely local action with minimal systemic complications.
Technique
Neurobotulinum toxin serotype A (NBS) is commercially marketed in two forms, the older Botox (Allergan inc. Irvine USA) and a more recent formulation Dysport (Speywood pharma Maindenhead UK). One unit of Botox is equivalent to 3 or 4 units of Dysport. 
Site of Injection The toxin may be injected into the Parotid or Submaxillary salivary gland. Some authors have advocated injection into both the parotid and submaxillary gland.
Dose The total dose varies from 10- 100 Units of Botox or 30 to 450 units of Dysport divided between the glands and the sites of injection. The toxin is injected in divided doses in two separate sites of the gland using ultrasound guidance under general anesthesia. 
Is it effective?
Studies on children with cerebral palsy and on individuals with Amyotrophic Lateral Sclerosis (ALS) have shown promising results.
While all research has shown a decrease in drooling and improvement in quality of life few authors have pointed out the risk of dry mouth at doses higher than 40 U of Botox ( 120 U Dysport). One study study on patients with cerebral palsy found a complaint of Dysphagia in 2 patients while another study on patients with ALS reported one case of recurrent mandibular luxation after injection into the parotid gland.
Each injection was effective for between 3 to 6 months.


While there is still much research to be done in this field Botulinum toxin looks to offer hope to patients with the embarrassing and sometimes dangerous problem of drooling of saliva.

Oral and Dental Problems of Children With Cerebral Palsy III - The Drooling of Saliva

The drooling of saliva is an embarrassing situation for both patient and care giver. An accompanying condition, seen in many forms of Cerebral Palsy, drooling can not only reduce the quality of life of your child but also have an adverse psychological impact.

What is Drooling?

Drooling is the spilling of saliva onto the lips, chin or in severe cases even onto the child's clothing. Drooling in cerebral palsy is not due to the production of excess saliva, it is caused because the child's muscles do not allow for a proper swallow. 

What are the effects of drooling?

Apart form the obvious social embarrassment, drooling can lead to a foul smell due to the accumulation of saliva in the corners of the mouth, soiling of the clothes and in very severe cases aspiration pneumonia. Aspiration pneumonia occurs when the lack of muscle coordination results in saliva entering the child's lungs. This saliva then acts as a source of infection that causes pneumonia. This condition can be life threatening.

Does drooling depend on the severity of CP?

To some extent it does. The worse the co-ordination between your child's nerves and  muscles, the worse is the drooling. But surprisingly drooling has no correlation with the intelligence or learning ability of your child. Children who have no intellectual disability often suffer from drooling. This makes drooling a particularly embarrassing problem. Drooling may prevent children from making friends at school or prevent them from expressing themselves.

How can we treat drooling?

In Many cases the severity of drooling reduces with age, even completely regressing in a few cases. The primary aim of the treatment of drooling should be to improve the strength and co-ordination of the child's facial muscles. In many western countries, drugs or injections to reduce the flow of saliva have been tried. These methods are described as successful because they reduce the flow of saliva and thus improve the quality of life of the patient. However these drugs can have a devastating effect on the teeth of the child.

If not drugs then what?

Drugs are not the only form of treating drooling. Parents must remember that since drooling is a neuromuscular problem, it will often get better as your child's muscles get stronger. In many children the severity of drooling reduces with age. Therefore it is not advisable to start the child on medications early. Exercises to help the child achieve closure of the mouth greatly help reduce the severity of drooling.  Speech therapy improves the child's control over the muscles of the tongue and also reduces the severity of drooling. 

Will my child require surgery to control the problem?

Surgery is often viewed as a last resort, when all other treatment has failed, in order to prevent aspiration pneumonia. Surgery may be of two types, firstly the surgeon may reduce the secretion of saliva, by repositioning the duct of the salivary gland or by removing the gland itself. This reduces the production of saliva, but leaves the child's mouth prone to infection, as it is devoid of the protective nature of the saliva. The second, more complicated surgery, involves the bypass of the oral cavity during feeding, ensuring that the child is fed directly through a tube inserted into the stomach; a procedure called a gastrostomy. This type of surgery is reserved for children who have had multiple episodes of aspiration pneumonia and is the exception and not the rule.

What the future holds

The use of Botox  for the management of drooling has been receiving a lot of attention in western countries. The drug more famous for its cosmetic uses, has a selective action on salivary glands. And even though it reduces the salivary flow, researchers claim that it is safer and has fewer side effects on the mouth than routinely used drugs. 

Another interesting  approach has been the use of oral appliances. Dentists often use the forces of the muscles to promote growth of the bones or help a child over come  habits like thumb sucking. Research shows that modified versions of these appliances can promote muscle coordination in Cerebral Palsy. While they cannot be used in the severe forms of Cerebral Palsy, they are said to be effective in milder forms. They are especially useful in children with no intellectual disability, who can understand the purpose of the appliance.

For Further Queries you can contact me;

Dr Sharat Chandra Pani

Consultant Pediatric and Preventive Dentist

Senior Lecturer

KVG Dental College

Sullia India

+919886374024

sharatpani@hotmail.com