Discomfort felt inside the cheeks, medically known as the buccal mucosa, is a frequent experience. This pain can range from a minor sting to a persistent ache that interferes with daily activities like eating and speaking. The mouth lining is delicate and constantly exposed to various physical, chemical, and biological stressors, making it susceptible to injury. Identifying the source of the pain is the first step toward finding relief, as causes vary widely from simple mechanical trauma to complex inflammatory responses.
Physical Causes of Cheek Injury
Mechanical damage is the most common cause of inner cheek soreness. Accidental cheek biting, often occurring while eating or speaking quickly, creates a break in the mucosal tissue that develops into a painful sore. This initial trauma leaves a raw spot that is often repeatedly re-injured by subsequent chewing, prolonging the healing process.
A repetitive, subconscious habit known as Morsicatio buccarum, or chronic cheek chewing, also causes physical injury. This compulsive behavior involves repeatedly gnawing on the inner cheek lining, leading to thickened, rough, or shredded white patches on the mucosa. These lesions are typically located along the occlusal plane where the teeth meet and cause chronic discomfort.
Dental hardware or irregularities in the mouth can create persistent friction or sharp irritation. Poorly fitting dentures, broken fillings with sharp edges, or protruding orthodontic wires and brackets can rub against the soft cheek tissue. This constant friction wears down the protective lining, resulting in localized inflammation and painful ulceration. Misaligned teeth or teeth deflected toward the cheek, such as erupting wisdom teeth, may also contribute to regular, involuntary biting.
Inflammatory Conditions and Infections
Pain arising without direct physical injury often stems from an underlying inflammatory or infectious process. Aphthous ulcers, commonly known as canker sores, are a frequent cause of non-traumatic inner cheek pain. These sores are shallow, round, or oval lesions characterized by a white or yellowish center and a distinct red border. Unlike cold sores, aphthous ulcers are not contagious and do not result from the Herpes Simplex Virus.
The development of aphthous ulcers is often linked to a disturbed immune response. Triggers include emotional stress, hormonal fluctuations, or minor trauma. Nutrient deficiencies, particularly low levels of B vitamins, iron, or folic acid, may also predispose individuals to recurrent outbreaks. These ulcers typically form on the soft tissues of the cheek and can be intensely painful for four to seven days before healing begins.
Infections can also manifest as painful cheek lesions, such as oral candidiasis, or thrush. Thrush is a fungal infection caused by an overgrowth of Candida albicans. This condition is characterized by creamy white patches that can be scraped off, sometimes revealing raw, red tissue underneath. Thrush is more common in individuals with weakened immune systems, those using inhaled corticosteroids, or people who have recently taken broad-spectrum antibiotics.
While less common on the buccal mucosa than the lips, certain viral infections can cause painful blisters. For example, Herpes Simplex Virus causes clusters of small blisters that eventually rupture to form ulcers.
Immediate Relief and Home Care
For minor injuries and common sores, several accessible home care strategies can help manage pain and encourage healing. Rinsing the mouth several times a day with a warm salt water solution helps keep the area clean and reduce inflammation. A mixture of one teaspoon of salt dissolved in warm water acts as a mild antiseptic rinse that can soothe the irritated tissue. Another effective rinse uses a solution of baking soda and water, which helps neutralize the mouth’s acidity and promotes healing.
Over-the-counter topical oral anesthetics, often containing benzocaine, can be applied directly to the sore to numb nerve endings and provide temporary pain relief. These gels create a barrier over the lesion, which is particularly helpful before mealtimes. For broader discomfort, systemic pain relievers like acetaminophen or ibuprofen can be taken to reduce pain and inflammation.
While a sore is healing, it is beneficial to avoid foods that can cause further irritation or physical abrasion. Highly acidic items like citrus fruits and tomatoes, spicy foods, and salty snacks can sting and aggravate the open tissue. Crunchy foods, such as chips or hard candies, should also be avoided, as they can inadvertently re-injure the delicate mucosal lining.
Warning Signs Requiring a Doctor Visit
While most inner cheek pain resolves within one to two weeks, certain red flags indicate the need for professional evaluation by a dentist or physician. Any sore or ulcer that persists and does not show signs of healing after 10 to 14 days should be examined. Prolonged, non-healing lesions may suggest a more serious underlying condition, such as a localized infection or, in rare cases, an early sign of oral cancer.
Severe symptoms that extend beyond the mouth also warrant immediate attention. These include intense swelling of the cheek or face, pain that impedes swallowing or breathing, or the presence of a fever or chills. These signs may indicate a serious infection that has spread beyond the mouth lining. Additionally, the appearance of persistent, unusual white or red patches, known as leukoplakia or erythropllakia, which cannot be wiped away, should be promptly assessed.