Sore and Burning Mouth
A Sore and Burning mouth is a relatively common clinical complaint in dental practice. It describes a range of uncomfortable sensations — including burning, tingling, pain, dryness, and soreness — affecting the oral mucosa, often without obvious clinical abnormalities. This symptom can have a complex and multifactorial etiology, requiring careful evaluation to determine the underlying cause.
One well-recognized form of this condition is Burning Mouth Syndrome (BMS), but it is important to differentiate primary (idiopathic) burning mouth from secondary burning sensations caused by systemic or local factors.
Understanding the causes, diagnosis, and management of sore and burning mouth is essential for dental professionals to provide effective patient care.
Definitions
- Sore Mouth: General term for oral discomfort that can include pain, tenderness, or irritation.
- Burning Mouth: Specifically refers to a burning or scalding sensation, often without visible mucosal lesions.
- Burning Mouth Syndrome (BMS): Defined as a chronic burning sensation of the oral mucosa without identifiable local or systemic causes, persisting for more than three months.
Epidemiology
- BMS affects approximately 1–5% of the general population.
- It is more common in women (especially postmenopausal women), with a female-to-male ratio of around 7:1.
- Peak incidence is between 50 and 70 years of age.
Common Symptoms
Patients with sore or burning mouth may report:
- Burning or scalding sensation, typically affecting the tongue, lips, palate, or entire mouth
- Dry mouth (xerostomia) or altered saliva consistency
- Altered taste sensations (dysgeusia), such as metallic or bitter taste
- Tingling or numbness
- Soreness exacerbated by talking, eating spicy foods, or stress
- Minimal or no visible lesions on examination in BMS cases
Etiology
The causes of sore and burning mouth can be divided into primary (idiopathic) and secondary.
1. Primary (Idiopathic) Burning Mouth
- No identifiable clinical or laboratory abnormalities.
- Thought to involve neuropathic mechanisms, such as:
- Small fiber sensory neuropathy
- Dysfunction in the central or peripheral nervous system
- Altered pain perception
- Possible association with psychological factors like anxiety or depression
2. Secondary Causes
Secondary sore/burning mouth is due to identifiable local or systemic factors:
A. Local Factors
- Oral candidiasis (fungal infection)
- Irritation from dental appliances (e.g., ill-fitting dentures)
- Allergic reactions (e.g., to dental materials, flavorings in toothpaste)
- Lichen planus or other mucosal diseases
- Trauma (from sharp teeth or biting)
B. Systemic Factors
- Nutritional deficiencies (iron, vitamin B12, folate, zinc)
- Diabetes mellitus (leading to neuropathy)
- Thyroid dysfunction (hypothyroidism)
- Hormonal changes (menopause)
- Medications (ACE inhibitors, antidepressants, chemotherapy agents)
- Psychological conditions (stress, anxiety, depression)
Diagnosis
Accurate diagnosis involves a systematic approach, given the wide range of potential causes.
History Taking:
- Onset, duration, and progression of symptoms
- Relationship to meals, stress, and sleep
- History of systemic diseases, medications, and lifestyle habits (e.g., smoking, alcohol use)
- Symptoms like dry mouth, taste disturbances, or mucosal changes
Clinical Examination:
- Thorough intraoral examination for signs of infection, trauma, or mucosal disease
- Denture evaluation (fit, hygiene)
- Assessment of salivary flow
Investigations:
- Blood tests:
- Complete blood count (CBC)
- Blood glucose levels
- Iron studies, Vitamin B12, Folate levels
- Thyroid function tests
- Fungal culture/smear to rule out candidiasis
- Allergy testing if indicated
- Sialography or salivary flow rate testing for xerostomia
If no cause is found, a diagnosis of primary BMS is considered.
Management
Management depends on whether the burning or soreness is primary (idiopathic) or secondary.
A. Management of Secondary Sore/Burning Mouth
Treat underlying causes:
- Fungal infections: Antifungal agents (e.g., nystatin, fluconazole)
- Nutritional deficiencies: Vitamin or mineral supplementation
- Diabetes/Thyroid disorders: Medical management in collaboration with physicians
- Local irritants: Adjust dentures, replace offending dental materials
- Allergies: Identify and eliminate allergens
Symptomatic treatments:
- Topical anesthetics (e.g., lidocaine gel) for temporary relief
- Saliva substitutes in xerostomia
B. Management of Primary (Idiopathic) Burning Mouth Syndrome
1. Patient Education and Reassurance
- Essential to explain the benign nature of the condition.
- Emphasize the importance of stress management and realistic expectations.
2. Pharmacologic Treatments
- Topical clonazepam (a benzodiazepine): Applied as a mouth rinse; reduces pain perception.
- Alpha-lipoic acid: An antioxidant that may improve neuropathic pain.
- Low-dose tricyclic antidepressants (e.g., amitriptyline) or gabapentin/pregabalin: Neuropathic pain modulators.
- Capsaicin rinses: Desensitize oral mucosal nerves.
3. Non-Pharmacological Approaches
- Cognitive-behavioral therapy (CBT): Effective in addressing psychological contributors.
- Stress management programs
- Mindfulness and relaxation techniques
- Acupuncture (some evidence supports benefit)
Prognosis
- Secondary burning mouth usually resolves once the underlying cause is treated.
- Primary BMS can be more challenging, often requiring long-term symptom management rather than a cure.
- Many patients achieve partial or complete symptom relief over time with combined therapy and psychological support.
Recent Advances and Research Directions
Emerging areas of research in sore and burning mouth include:
- Neuroimaging studies: Reveal altered brain activity in pain-processing regions in BMS patients.
- Genetic studies: Explore polymorphisms linked to pain perception.
- Salivary biomarkers: Investigating oxidative stress markers for diagnosis and monitoring.
- Novel treatments: Such as transcranial magnetic stimulation (TMS) for neuropathic pain.
Summary Table: Causes of Sore and Burning Mouth
| Category | Examples |
|---|---|
| Local factors | Candidiasis, trauma, allergies, denture irritation |
| Systemic factors | Diabetes, hypothyroidism, nutritional deficiencies, hormonal changes |
| Medications | ACE inhibitors, antidepressants |
| Psychological factors | Anxiety, depression |
| Primary BMS | Idiopathic, neuropathic dysfunction |
A sore or burning mouth is a symptom with diverse causes, ranging from simple local infections to complex idiopathic neuropathies like Burning Mouth Syndrome. A systematic diagnostic approach, identifying and managing any underlying conditions, combined with symptomatic relief and psychological support, is key to effective management.
For dental practitioners, understanding the multifactorial nature of this condition enhances patient care, builds trust, and improves long-term outcomes.