Allergies, often viewed as a respiratory nuisance, can affect oral health and the teeth. The systemic inflammatory response triggered by allergens leads to effects on the mouth. These impacts generally fall into two categories: referred pain from congestion and the pathological consequences of a reduced protective environment. Understanding these mechanisms is the first step in protecting your smile during peak allergy season.
Referred Pain from Sinus Congestion
The maxillary sinuses, the largest facial air cavities, are positioned directly above the roots of the upper back teeth. When an allergic reaction causes inflammation and fluid buildup, or congestion, within these sinuses, the internal pressure increases considerably.
This elevated pressure pushes downward on the thin bony floor of the sinus cavity, which is close to the nerve endings of the upper dental roots. The sensation is often misinterpreted by the brain as coming from the tooth itself, a phenomenon known as referred pain. As a result, many people experience a dull, throbbing ache across several upper teeth, feeling exactly like a severe cavity or dental infection.
Sinus-related tooth pain typically affects multiple teeth on one or both sides of the upper jaw, rather than being localized to a single tooth. This discomfort often intensifies with changes in head position, such as bending over or lying down, due to the shifting fluid pressure within the sinus. When a dentist examines these teeth, diagnostic tools usually reveal no actual dental pathology.
Xerostomia and Increased Risk of Dental Decay
One damaging effect of allergies on oral health is the development of xerostomia, or chronic dry mouth. Saliva plays a fundamental role in maintaining oral health by neutralizing acids, washing away food particles, and providing minerals for enamel remineralization. When saliva flow is reduced, the mouth loses its primary defense mechanism.
Allergies lead to dry mouth through two main pathways: mechanical and pharmacological. Nasal congestion often forces an individual to breathe through their mouth, especially during sleep, which causes the constant evaporation of moisture from the oral tissues. This mechanical drying significantly reduces the protective layer of saliva.
The use of common allergy medications, particularly older generation antihistamines, also contributes to dryness. These drugs have anticholinergic properties that inhibit saliva production by blocking the nerve signals that stimulate the salivary glands. Even some newer second-generation antihistamines and decongestants can contribute to reduced salivary flow.
The consequence of persistent xerostomia is a shift in the oral microbiome, allowing harmful bacteria to thrive. Without the acid-buffering capacity of saliva, the mouth becomes more acidic, accelerating the process of enamel erosion and tooth decay. Reduced saliva also increases the risk of gingivitis, gum irritation, and plaque accumulation, making the teeth more vulnerable to long-term damage.
Managing Oral Health During Allergy Season
Mitigating the dental side effects of allergies requires a proactive approach focused on maintaining moisture and reinforcing dental protection.
Hydration and Saliva Stimulation
Staying thoroughly hydrated by drinking water throughout the day is an effective way to counter the effects of dry mouth. Using a cool-mist humidifier at night can also help introduce moisture into the air, reducing the drying effect of mouth breathing.
To directly stimulate saliva production, chewing sugar-free gum or sucking on sugar-free lozenges containing xylitol is beneficial. Xylitol promotes salivary flow and helps reduce harmful bacteria in the mouth. Patients should also consider using specialized, alcohol-free dry mouth rinses or moisturizing gels, as alcohol-based products can worsen dryness.
Hygiene and Diagnosis
Maintaining rigorous oral hygiene is particularly important when saliva is compromised. Brush twice daily with fluoride toothpaste and floss meticulously.
For localized, sharp pain, a dental check-up is necessary to rule out a true cavity or infection. However, if the pain is dull, affects multiple upper teeth, and is accompanied by nasal congestion, addressing the underlying allergy with an allergist or primary care physician is the appropriate first step to relieve the referred dental discomfort.