GERD is the acronym for GastroEsophageal Reflux Disease. It is also known as ARD–Acid Reflux Disease. Bulimia, on the other hand, is the name given to an eating disorder in which a person binges on food and then vomits it up in order to loose weight. Although these diseases have vastly different etiologies (root causes), they are covered here on the same page because, for all practical purposes, they have nearly identical clinical effects on the palatal aspects of the anterior incisors and canines. Both GERD and bulimia are caused by the reflux of stomach acid, either intentionally as in bulimia, or unintentionally as in acid reflux disease.
Bulimia has the worst effects on the lingual aspects of the anterior teeth, while GERD effects the posterior teeth more than the anterior. The pattern of the erosion in bulimia and GERD corresponds to the position of the tongue during episodes of regurgitation. A patient bent over the toilet vomiting tends to cover the back teeth with the tongue, while allowing the vomit to flow out over the anterior teeth. This protects the posterior teeth from the stomach acid while fully affecting the anteriors. In GERD, the patient tends to bring up stomach acid and then reswallow it, and this set of reflexes allows the acid to affect the lingual aspects of the posterior teeth as well as the anterior teeth.
GERD and Bulimia both effect the lingual aspects of the anterior maxillary (upper) teeth in about the same way. As the palatal surfaces of the maxillary incisors erode, the incisal edges become more and more thin and translucent, eventually producing a knife-edge which is easily crazed and chipped. In the image above, nearly all of the palatal enamel has been dissolved by the acidic stomach contents. The patient’s posteriors are nearly unaffected. Note especially that the erosion stops abruptly at the gingival margin.
Compare the image below with the ones above. This is also an image of the palatal aspects of the maxillary incisors in a patient who grids their teeth (bruxes). The severe wear might be mistaken for bulimia or GERD, but the position of the wear is above the free gingival margin, unlike bulimia in which the erosion goes exactly to the free gingival margin. Also note the irregularity of the margins themselves. These correspond to the shape and position of the lower incisors. Plaster models of the upper and lower teeth would show that the lower incisors fit exactly into the defects at the gingival margins.
As an interesting aside, it is very difficult to come by images of the teeth of bulimia patients while there is no shortage of images of acid reflux. This has much less to do with the frequency of their appearance, than it has to do with the personalities of the respective patients. Most bulimia patients are very self conscious of their disorder, and very few will permit pictures to be taken of their teeth.