Anorexia and bulimia and the effects on your teeth

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Anorexia and bulimia and the effects on your teeth

Eating disorders are bad news for teeth

Eating disorders affect around 15% of young girls to varying degrees, around five to ten times more than men. These illnesses involve a constant preoccupation with food, a distorted body image and excessive measures taken to control weight… excessive to the point of harming your body’s health, as well as, your mental health and interpersonal relations.

The most common eating disorders are anorexia nervosa (restriction of food intake) and bulimia (episodes of compulsive eating). These two illnesses can alternate or follow one another. They are often accompanied by purges or compensatory behavior intended to limit weight gain (making yourself sick, use of laxatives, fasting and physical hyperactivity). In its most severe form, anorexia nervosa leads to a BMI of less than 17.5 and hormonal disruption. It affects between 0.9% and 1.5% of women and 0.2 to 0.3% of men.

Professor Pierre Colon, a dental surgeon teaching restorative dentistry and endodontics, describes the havoc eating disorders wreak in your mouth: “In the first few years of the illness, teeth will become worn and cracked. Most of this damage is due to vomiting, and anorexia, where food is restricted, can also have harmful effects on the teeth. The lifestyle habits peculiar to these patients are always taken into account.”

Dental damage characteristic of eating disorders

Damage to the teeth associated with eating disorders are usually signs of both mechanical and chemical wear. As Professor Colon explains: “The enamel is weakened (eroded) by an excess of acid from diverse origins in the body, and gets thinner until it almost disappears, exposing the dentine which is sensitive. At the same time, this phenomenon is exacerbated by the action of the teeth against each other (attrition) or by inappropriate brushing and even by certain foods (abrasion). The area where the damage is worst indicates the cause.”

Logically, the damage caused by vomiting will be where the stomach acid has come into contact with teeth, mostly affecting the backs of the teeth, facing the palate and at the gum line around the incisors. Over time, the enamel will disappear totally on the insides of the teeth. Teeth wear down into a point and lose their height.

Bulimic episodes and also certain types of food can also mean those suffering from eating disorders may be exposing their teeth to gastroesophageal reflux, often during the night, which means acid erosion can take place without the sufferer even being aware of it. “The damage caused by acid reflux is usually around one side of your jaw according to your sleeping position”, Professor Colon comments.

However, damage can also be caused to the front of the teeth, through drinking a lot of acidic drinks. Professor Colon explains this further: “To fill up an empty stomach or help provoke vomiting, certain patients swallow almost six liters of soda a day. It is actually a well-known fact that these drinks are one of the key causes of acid erosion. You also have to be careful of salad dressings, often acidic like, vinaigrettes with contain lemon juice and mustard…”

The chewing surface of the molars does not escape damage either. There is often not enough saliva present in the mouth, and it is often in bad shape due to malnourishment, so your spit cannot neutralize the acidity in your mouth. The damage to the edges of your teeth which jut out will be worn down into wells which spread and grow. Your molars will end up losing their shape and height.

Finally, in extreme cases of anorexia, the gums can recede so far that they expose the roots of your teeth to acid and to the damaging brushing action of your toothbrush. With the idea of cleansing the body, or to get rid of the taste of vomit, some patients brush their teeth ten or fifteen times a day, sometimes for twenty minutes!

Different types of decay and dental pain

Teeth are weakened by acid erosion, they are not protected properly by saliva and the body’s immune defenses are down, but on top of all this, people who suffer from eating disorders consume more sugary foods, as well, during an attack of compulsive eating. They also drink more fizzy drinks and sugary things in order to make themselves vomit. Tooth decay is therefore rapidly increased.

Due to enamel loss, teeth become more painful and sensitive to the cold, acid, sugar and even brushing. The dentine, naturally more yellow than enamel, stains easily on contact with food and will affect your smile.

After ten years, often at around 28 or 32 years old, the wearing down of your teeth becomes visible, ruining your appearance and affecting your ability to eat, so much so, teeth will even start to crack. “In some patients, the incisors will only be a few millimeters tall, and the molars will barely clear the edge of the gums with gaping holes in the dental arches”, explains Professor Colon. This loss of surface can lead to pain when articulating your jaw, and even trigeminal neuralgia which is an extremely painful condition.”

Stopping the damage to your appearance and dental function

When patients are still battling these disorders, Professor Colon recommends rinsing the mouth after vomiting with tap water, and waiting at least twenty minutes before brushing your teeth. This advice is also applicable after eating acidic food or having fizzy drinks.

Teeth should be brushed vertically, from the gum line towards the ends, and using a technique which allows the bristles of the toothbrush to reach in between the teeth. Use a flexible toothbrush and a non-abrasive toothpaste, ideally formulated for protecting the enamel. “Electric toothbrushes can be useful as certain models cut out when the pressure on the teeth is too strong”, Professor Colon points out. There are also dental treatments available which specifically target erosion.

Often, people who are affected by eating disorders are also smokers, drinkers and often take different drugs which also have an effect on teeth (staining, acid erosion, reduced saliva production and general poor health). On the other hand, chewing sugar-free gum from time to time will stimulate the production of saliva and limit acid reflux.

“The feelings of guilt and shame mean many sufferers do not go to the dentist”, Professor Colon says regretfully, but consulting a dentist means the damage can be limited. When the illness is not being fought off, a dentist might suggest a local administration of fluoride and replacement of lost enamel and dentine with resin which will build the teeth back up, preserving the natural shape and colour of your teeth. “Restorative materials have the advantage of preserving the healthy part of the tooth” Professor Colon points out. Once patients begin treatment, it is possible to achieve perfect results with restorative dental work.”


  • This figure, provided by Dr. Nathalie Godard (at the Institut Mutualiste Montsouris) comes from a literature review dated June 2008, and concerns all eating disorders. Anorexia and Bulimia represent 5% of cases.
  • These diagnostic criteria are taken from the International Statistical Classification of Illnesses and Related Health problems (ICD-10 code by the World Health Organization) and the Handbook of Diagnosis and Treatment of DSM-IV Personality Disorders. Refer to Anorexia Nervosa: Treatment, Official definition by the French National Authority for Health, June 2012, p. 13-14.

*Pierre Colon is a professor at the Paris Diderot University, and a clinical practitioner in restorative dentistry and endodontics for the Garancière dental practice at the Rothschild Hospital (AP-HP, Paris). He is researching the chemistry of materials as part of the Biomaterials and Biological Interfaces team at the Multimaterials and Interfaces Laboratory UMR CNRS 5615 at Lyon 1 University.