Anorexia nervosa, a complex eating disorder characterized by severe restriction of food intake, has profound physical consequences that extend far beyond weight loss. The disorder significantly compromises oral and dental health through two pathways: direct chemical trauma from purging and systemic breakdown caused by chronic malnutrition. Changes to the teeth and mouth are often among the earliest physical manifestations of the condition, making an understanding of these effects important for early detection and management.
Acid Erosion: The Direct Impact of Purging
Frequent self-induced vomiting exposes the teeth to highly corrosive gastric acid, which has a pH as low as 1.5 to 3.5. This repeated chemical attack causes a specific pattern of wear known as perimylolysis, which is the dissolution of tooth enamel and underlying dentin. Although enamel is the hardest substance in the human body, it cannot withstand prolonged exposure to this strong acid.
The erosion typically affects the surfaces that contact the acid first and longest, primarily the lingual and palatal surfaces of the upper front teeth. The lower teeth are often less affected because the tongue acts as a protective barrier against the flow of vomit. As enamel wears away, the teeth may take on a smooth, glassy, and translucent appearance, sometimes leading to yellowish discoloration as the underlying dentin becomes exposed.
Loss of the protective enamel layer leads to increased tooth sensitivity, especially to hot and cold temperatures. In advanced stages, the structural integrity of the teeth is compromised, causing them to become brittle, which can result in chipping or fracture along the biting edges.
A common mistake that compounds this damage is brushing the teeth immediately after purging. Brushing while the enamel is softened and demineralized by acid causes mechanical abrasion, scrubbing away the weakened tooth structure. Individuals should wait at least one hour before brushing to allow saliva to begin the natural remineralization process. The correct immediate protocol involves gently rinsing the mouth thoroughly with plain water or a solution of water mixed with baking soda to neutralize the acid.
Systemic Effects: Nutritional Deficiencies and Salivary Changes
Beyond the localized damage from purging, the chronic state of malnutrition and restricted intake creates systemic problems that weaken the entire oral environment. Deficiencies in micronutrients like calcium and Vitamin D directly affect the body’s ability to maintain strong bone structure, including the jawbones that support the teeth. A lack of calcium can cause the body to draw this mineral from its reserves, potentially weakening the alveolar bone and increasing the risk of tooth looseness or loss.
Inadequate intake of Vitamin C and various B vitamins can lead to compromised soft tissue health, resulting in swollen, tender, or bleeding gums (gingivitis). Over time, this inflammation can progress to periodontitis, which involves the destruction of the tissues and bone supporting the teeth. Iron deficiency, also common with poor nutrition, further diminishes the immune system’s ability to fight off oral infections.
Dehydration and the body’s weakened state frequently cause chronic dry mouth (xerostomia), which is a significant factor in dental disease. Saliva is the mouth’s natural defense mechanism, containing minerals and buffers that neutralize acids and wash away food particles and bacteria. Reduced saliva flow eliminates this protective function, leading to a rapid increase in the risk of dental caries, or cavities. Another common physical sign is the non-inflammatory swelling of the salivary glands, particularly the parotid glands, a condition called sialadenosis.
Strategies for Protecting Dental Health
Managing the dental complications of anorexia nervosa requires a collaborative and specialized approach focused on mitigation and restoration. Individuals should openly communicate their condition with their dental care team, allowing the dentist to implement a tailored, low-abrasion care plan. Dental professionals are often the first to recognize the physical signs of the disorder, and providing this information allows for proper monitoring of erosion and mucosal lesions.
Dentists can prescribe treatments to help remineralize weakened enamel and decrease sensitivity. This often includes in-office fluoride varnish applications and prescription-strength, high-fluoride toothpaste or rinses for daily use. For teeth with significant erosion, restorative procedures like bonding, fillings, crowns, or protective sealants may be necessary to rebuild lost structure and restore function.
Daily oral hygiene habits must be adapted to protect fragile teeth. Using a soft-bristled toothbrush and a low-abrasive toothpaste is recommended. Chewing sugar-free gum containing xylitol can help stimulate saliva production, restoring some of the mouth’s natural buffering capacity. While these dental strategies can manage and limit the progression of oral damage, sustained long-term improvement ultimately depends on addressing the root cause through comprehensive medical and psychological treatment.