disorder. There are three such disorders to be aware of: anorexia nervosa; bulimia
nervosa; and, more rarely, rumination (this is a condition of unknown aetiology in
which food is voluntarily regurgitated into the oral cavity and either expelled or
swallowed again).
Anorexia nervosa is a sociocultural disease mainly affecting middle-class, intelligent,
females between 12 and 30 years of age. Like bulimia nervosa it is a secretive disease
with sufferers denying illness and refusing therapy. People with anorexia exhibit
considerable weight loss (up to 25% of their body weight in severe cases), have a fear
of growing fat, and a distorted view of their body shape. While those with bulimia
suffer characteristic binges on 'junk foodstuffs' and follow this with self-induced
vomiting, overzealous exercise, and the use of laxatives to prevent weight gain⎯they
may subsequently develop GORD, which causes typical signs of heartburn and
oesophagitis.
The pattern of erosive tooth loss seen in all patients who suffer from chronic gastric
regurgitation is similar, with marked erosion of the palatal surface of upper incisors
and premolars. There is a surprising lack of tooth sensitivity. Over time, the buccal
and occlusal surfaces of the lower molars and premolars also become affected (569HFig.
10.19 (a) and (b)).
As a result of the asymptomatic nature of some of the gastrointestinal disorders and
the secretive nature of the eating disorders, dentists may well be the first professionals
to see the signs of gastric regurgitation. The presence of erosive tooth surface loss
may be the only sign of an underlying disorder, and such a finding should be taken
seriously and handled carefully in communication with medical colleagues.
Parafunctional activity
Localized, tooth surface loss frequently occurs in patients who exhibit abnormal
parafunctional habits. The excessive grinding that is a feature of this problem is not
always apparent to the patient; however, apart from the marked tooth tissue loss, other
signs of bruxism may be evident including hypertrophy of the muscles of mastication,
cheek biting, and tongue faceting. An example of erosion and parafunction having a
disastrous effect on the dentition may be seen (and heard) in children who have
cerebral palsy. These children often have chronic gastric regurgitation and also severe
bruxism resulting in excessive tooth surface loss.