Contents
INTRODUCTION
FUNCTIONS OF SALIVA
PROBLEMS
TOOTH PHYSIOLOGY
1. Acidic foods and drinks
2. Dental Decay
MANAGEMENT
Fluid replacement and Mouth Moistening
1. Gustatory sialogogues
2. Glandular massage
3. Saliva substitutes
Dental decay
1.Overview
2. Avoid acid juices and avoid acid oral swabs
3. Oral hygiene
Dentures
Infections
Some commercially available products to assist in
the management of xerostomia
Example protocol for the management of a dental
patient with xerostomia which could be expected from a dentist
SUMMARY
INTRODUCTION
Every day, over a 24 hour period, the average person produces at
least 500ml of saliva. This material, which is a very complex fluid,
is secreted mainly by three paired salivary glands. The largest, the
parotid glands, are situated just below the ear and behind the angle
of the lower jaw. The sub-mandibular glands are sited just in front
of the angle of the lower jaw on its inner surface and the sub-lingual
glands which are situated toward the front of the floor of the mouth
between the tongue and the inside of the lower jaw. There are also
many minor salivary glands under the mucosal surfaces throughout the
oral cavity. Salivary flow rates vary considerably during any one
24 hour period depending on the demand or the current physiological
status of the patient, for example:
In Sjogren's Syndrome the production of saliva diminishes in proportion
to the degree of progressive destruction of the salivary gland tissue.
Diagnostic tests for xerostomia [pronounced 'zerro-stow-meeuh'] may
include measuring the flow rate of the saliva; scintigraphy [where
a dye is absorbed through the duct of the gland and is then measured
in the gland substance]; microscopic examination of some of the salivary
gland tissue usually removed from either the lower lip or the parotid
gland. These special tests, when combined with the patient's history
is usually sufficient to confirm the diagnosis. The spectrum of other
signs and symptoms associated with the Sjogren's Syndrome may also
be present to a variable degree.
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FUNCTIONS OF SALIVA
Saliva is an important component of the environment of the oral cavity
for many reasons. It is a natural cleansing agent of the teeth and
gums helping to wash away accumulated food, debris, bacteria and plaque.
It lubricates the soft tissues of the mouth including the gums, tongue,
palate, floor of the mouth, cheeks and lips and, more importantly,
the throat enabling swallowing to easily occur.
Saliva contains numerous proteins such as amylase [one of the digestive
enzymes which starts the break-down of starch in some foods] and immunoglobulins
which help to counteract infections and the stickiness of bacteria
adhering to the teeth and soft tissue. In xerostomia some proteins
may be missing or may be altered in their composition and function.
Saliva contains many inorganic elements, such as calcium and phosphate,
which help to remineralise the teeth making them less susceptible
to dental decay.
Saliva also contains buffering ['acid soaking up'] systems which
neutralise and inhibit the effects of acids produced by the oral bacteria
or which are included in the diet.
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PROBLEMS
Xerostomia and hyposalivation [less salivary flow than normal] may
be a most unpleasant and devastating problem for the patient with
Sjogren's Syndrome. Decreases in the quality as well as alterations
in the composition of the beneficial constituents of saliva predispose
the patient to many problems.
The lips may become dry, sore and cracked. A common complaint is
a dry and burning tongue. Swollen, tender salivary glands and angular
cheilitis [a cracking of the corners of the mouth] can be unpleasant.
All the soft tissues of the oral cavity may have a thinner layer of
cells than normal and, therefore, may be more susceptible to damage.
Taste sensation can be altered because there is inadequate liquid
to dissolve tastants in the food so that the taste buds can be activated.
Sjogren's patients may be prone to secondary oral infections, principally
from the yeast-like organism, Candida albicans, which produces the
condition candidosis [thrush]. Candidosis may present clinically in
a variety of forms, the most common being a generalised inflammation
of the mucosal [skin] surfaces of the mouth and tongue on which there
can be small superficial whitish patches. These may be removed leaving
a red area underneath which often bleeds easily. The corners of the
mouth may be infected [angular cheilitis] and this is a common problem
especially in denture wearers. Candidosis may be associated with a
tender/burning sensation which can be aggravated by hot or spicy foods.
Lack of saliva may affect the nutritional status of the individual
because eating and swallowing becomes such a time-consuming ordeal,
while talking and conversing may become impossible without frequent
sips of water or alternative lubricants.
Denture wearing may become difficult because dry mouth can significantly
add to the problem of retaining and eating with the dentures, which
invariably become loose.
Of particular importance is the problem of greatly increased dental
decay which can occur in patients who have their own natural teeth.
In order to understand why the teeth can demineralise or decay so
rapidly when there is a dry mouth some understanding of the physiology
of the oral cavity is necessary.
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TOOTH PHYSIOLOGY
Tooth structure is rather like reinforced concrete. There is a framework
of tough, strong collagen fibres [like the steel framework of a building],
around which is deposited the crystalline minerals of the tooth [concrete]
that gives the structure its rigidity and toughness. The crystal/mineral
part can be dissolved out by acids. In a patient with normal
salivary function there is a balance between the minerals contained
in the saliva [which is saturated with calcium salts] and tooth structure.
That is, should a small amount of mineral be dissolved out of the
tooth, then calcium crystals will tend to be deposited back into the
tooth via the saliva. This process is greatly enhanced by the presence
of 'fluoride ion' [which is the reason for the incorporation of fluoride
in water and toothpastes] and the re-formation of tooth mineral crystals
is rather like the way in which crystals of alum or copper sulphate
can be built up in a school chemistry experiment.
The structure of the teeth will actually start to dissolve away in
solutions where the pH [acidity] is 5.5 or less! The scale which measures
degrees of acidity or alkalinity is known as the 'pH' scale, where
pH 7 is neutral, pH 14 is highly alkaline and pH 0 is highly acid.
Thus,
normal salivary flows with normal mineral content and normal buffering
capacity [normal 'acid soaking up' properties], is a most important
physiological mechanism for maintaining the integrity of tooth structure.
When saliva is reduced or absent then mineral replacement of tooth
structure does not occur, any acid attack on the tooth lasts for longer
and, as a consequence, there is a net loss of calcuim salts from the
tooth structure and dental decay rapidly supervenes.
Under what conditions does the tooth environment become sufficiently
acid to cause mineral loss? There are, in fact, two ways in which
this can occur.
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1. Acidic foods and drinks
Food and beverages which are part of the normal diet can vary considerably
in acidity or alkalinity. It is important to know that commercially
available carbonated fizzy drinks and fruit juices, eg Coke, Fanta,
Lemonade, L&P, Fresh Up, Just Juice, McCoy, Twist, Arano etc [this
is not a complete list], range from pH 3.8-2.4. Although some fruit
juices have a natural acidity all products are adjusted to have pH
3.8 or less in order to prevent bacterial contamination and to prolong
shelf life. Lemon and Glycerine Mouth Swabs, designed to 'freshen
up the mouth', also have pH 2.4.
In other words all these products are capable of
dissolving tooth structure and can demineralise the teeth. Such beverages
tend to be drunk, sipped frequently or used during the day by people
with dry mouth to keep the mouth moist. Usually, in a person with
normal salivary flow, not much damage occurs [unless the materials
are used habitually or excessively] because the normal compensatory
mechanisms described above are active and any adverse effects of food
or beverage acids is rapidly eliminated. But tooth mineral loss in
a person who has xerostomia can be significant under these conditions
because the compensatory mechanisms are absent or reduced. This does
not mean that such drinks should be completely avoided.
It does mean that they should not be used continually
as mouth moisteners or oral lubricants.
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2. Dental Decay
In the mouth there are some 27 species of microorganisms [bacteria]
to be found. These are considered to be normal inhabitants of the
oral cavity in the same way that all parts of the body have a normal
resident microflora. In the mouth these microorganisms grow rapidly
over the tooth surfaces forming 'dental plaque'. Plaque is usually
partially removed by regular oral hygiene methods such as tooth brushing
and flossing but it is impossible to remove every vestige of plaque
from all the nooks and crannies of the teeth and gums and after tooth
cleansing plaque builds up again quite rapidly by bacterial cell division
and multiplication.
Some species [families] of plaque microorganisms use sugars in the
diet for their own energy and metabolic requirements. Their waste
products are strong organic acids which are excreted into the plaque
thus creating an environment around the teeth which is acidic enough
to dissolve the minerals out of the tooth. In fact, the acidity of
the plaque may fall as low as pH 2.5!
In a patient with normal salivary flow the effects of this acid production
are, again, quite quickly neutralised by the diluting and buffering
action of saliva. When there is reduced or absent saliva the acids
remain undiluted, the buffering systems do not work and the tooth
structure is exposed to the effects of acid for much longer which,
in turn, leads to greatly increased tooth decay. Careful attention
to oral and tooth hygiene is important in all patients but is mandatory
in those who have xerostomia where plaque control is of vital significance
in the prevention of dental decay. Plaque control may be enhanced
by the regular use of antiseptic mouthrinses [eg chlorhexidine gluconate
0.2% (products: Savacol by Colgate or Chlorhexidine Mouthwash by Delta
West)]. The use of a fluoride containing toothpaste is also recommended.
Hence, the action of the oral bacteria on the sugar sweeteners
in foods and drinks to produce acidic plaque together with the acidity
of the drinks themselves can cause an additive effect and the end
result can be an increase in dental decay and tooth demineralisation.
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MANAGEMENT
Xerostomia and its sequelae are managed according to severity.
Fluid replacement and Mouth Moistening
The most pressing need so far as the patient is concerned is the
need for some sort of fluid replacement in the mouth to diminish oral
discomfort and aid speech and swallowing and for the patient to maintain
good hydration at all times.
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1. Gustatory sialogogues
If there is some secretory glandular tissue working, it can be stimulated
by chewing gums for example. This may be sufficient to maintain adequate
lubrication in the mouth between meals for talking and normal activities.
However, it is vital that if you have your own natural teeth, such
gums or sweets are sugar free [otherwise dental decay via conversion
of sugar to acids by the microflora in the mouth will occur]
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2. Glandular massage
When salivary flow rates are diminished, the secretions may frequently
become viscous and can be retained within the ductal system. This
may cause glandular swelling and tenderness which, of course, needs
to be distinguished from infection. There are two pairs of large saliva
glands which pour most of the saliva into the mouth. The parotid glands
are below the ears and just behind the lower jaw. The submandibular
glands are tucked under the lower jaw towards the back.
The parotid gland may be ‘milked’ by placing the tips
of the fingers on the cheeks just in front of the ear, then pressing
firmly whilst dragging the fingers forward over the cheek skin. This
has the effect of emptying the parotid duct as it lies just beneath
the skin in this region. The manoeuvre can be repeated several times
with the fingers being positioned more ‘down and back’
with each stroke, in order to compress and progressively empty the
parotid gland. This often clears the gland enabling saliva to flow
from the ductal system more freely and can be repeated as often as
required.
The submandibular gland is more difficult to clear in this fashion.
To empty, for instance, the right submandibular gland, the left index
finger is placed as far back as possible along the floor of the mouth
under the tongue, whilst the index and third fingers of the right
hand compress the body of the gland by pressing on the skin under
the lower jaw just in front of the angle. The left index finger is
then drawn along the floor of the mouth towards the midline, compressing
the duct as it lies in this position, expressing secretions from the
duct orifice just behind the lower front teeth. Again, this may repeated
several times and the positioning reversed for the other submandibular
gland.
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3. Saliva substitutes
These are used when there is insufficient or no functioning glandular
tissue or when the previous methods are still inadequate.
a) Water
It is highly acceptable at the present time to carry, and sip frequently
from, a plastic bottle containing liquid. In patients with xerostomia,
water sipped frequently, still remains a very effective, innocuous
mouth moistener and doing so in public does not attract attention.
Water, however, is a poor lubricant.
b) Other oral lubricants/saliva substitutes
A number of preparations have been designed to both moisten and
coat the oral tissues in an attempt to mimic saliva but these are
surprisingly unsuccessful with respect to consumer compliance. Part
of the problem is that of product cost [for commercial products],
part because the covering agent in many products is carboxymethylcellulose
or related materials which have a ‘greasy’ texture in
the mouth that is unacceptable to many patients.
c) Recent Anticariogenic materials.
A new nontoxic product based on milk casein designed for use as
a mouth moistener, Dentacal Mouth Moistener has very recently become
available. This material contains calcium and phosphate and has
been shown to be equivalent to a standard fluoride mouth rinse in
its ability to reduce dental decay.
d) Pilocarpine
The drug Pilocarpine appears to be a useful sialogogue [salivary
stimulant] but, as with all drugs, there are side effects and the
patient needs to be carefully screened for heart disease, diabetes
and other medications first. Although this drug may increase salivary
flow, patients can find the side effects unacceptable.
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Dental decay
1.Overview
It can be seen that in order to prevent, as much as possible, the
problem of extensive and rapid dental decay and to ensure that dentures
are maintained, regular dental examinations are a priority. In the
case of those who have their natural dentition a dentist should be
able to advise in appropriate oral hygeine techniques eg brushing
flossing, antiseptics, fluoride applications/rinses. Use F' toothpastes.
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2. Avoid acid juices and avoid acid
oral swabs.
Many people resort to using fruit juices/carbonated fizzy drinks
to make the mouth feel nice and to keep it damp. Unfortunately, if
used habitually, all of these drinks will demineralise the teeth.
3. Oral hygiene
In patients with their own teeth, immaculate dental hygiene is mandatory
in order to minimise tooth destruction.
Plaque control:
VERY regular dental recall
Patients may need to be reviewed as frequently as every 4 months.
Calculus accumulation is seldom a problem in xerostomia because of
the reduction in calcium salts being secreted into the mouth.
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Dentures
Attention must be given to diet which should be palatable, edible
and nutritious. Xerostomia can lead to patients becoming socially
compromised because of their inability to eat certain foods - those
often nominated as the worst are bread and chicken. Many people will
not go out to eat because they feel that they may offend their host
if they are unable to eat the prepared food or because it takes so
long to consume the meal. This can be acutely embarrassing.
A dietician may be part of the management team and can offer individual
advice concerning suitable food preparation/food types. It must also
be noted that many people with xerostomia are unwell and the diet
must be practical and within their abilities to prepare. In-between-meals
snacks for dentate patients should be minimised as these often tend
to be carbohydrate in nature and contain sugars which encourages dental
plaque, acid production and demineralisation.
A patient information booklet ‘Cooking Solutions: For people
with dry mouthsã’ has recently been compiled which describes
the role of saliva, causes and problems of xerostomia and offers hints
about diet and food preparation. This is available on application
to: Dr David Hay, Oral Health Regional Service, Green Lane Hospital,
Green Lane, Auckland ($10.00 per copy).
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Infections
Infections of the salivary glands require antibiotic therapy or,
if persistent, consideration may need to be given to surgical removal
of the gland/s. Candidosis may require prolonged courses of antifungal
agents such as nystatin, amphotericin or miconazole. These pharmacological
agents should only be prescribed by a doctor or dentist.
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Some commercially available products to assist
in the management of xerostomia
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Example protocol for the management of a dental
patient with xerostomia which could be expected from a dentist
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SUMMARY
The general management of the oral problems associated with this
extremely unpleasant and inconvenient disease have been outlined in
this paper and the importance of regular dental maintenance has been
emphasised.
