Discovering an unexpected bump on the inside lining of your cheek, known as the buccal mucosa, often causes concern. While any new growth should be observed, the vast majority of these oral lesions are benign and result from simple, identifiable causes. The mouth lining is highly sensitive to injury and inflammation, frequently reacting to trauma by forming protective tissue or fluid-filled pockets. Understanding the underlying mechanism of the bump can guide the next steps toward resolution or professional consultation.
Bumps Caused by Chronic Irritation
The most frequent cause of a persistent bump inside the cheek is chronic physical trauma, which leads to the formation of a traumatic fibroma or irritation fibroma. This growth is essentially a localized buildup of scar tissue, representing the body’s attempt to protect a repeatedly injured area. These fibromas commonly develop along the bite line, where the upper and lower teeth meet, often resulting from habitual cheek biting or friction.
The source of the irritation can also be a sharp tooth edge, a poorly fitting dental appliance, or the roughness of an old filling. A traumatic fibroma presents as a firm, smooth, and dome-shaped lump, typically the same color as the surrounding mucosa. These lesions are usually painless, slow-growing, and may reach about one centimeter in diameter.
Fibromas do not disappear on their own and do not pose a risk of turning into oral cancer, but they can become bothersome if trauma continues. Definitive treatment often involves minor surgical excision performed by a dentist or oral surgeon under local anesthesia. To prevent recurrence, the source of the chronic irritation must be eliminated, such as adjusting a dental appliance or smoothing a sharp tooth.
Fluid-Filled Swellings from Salivary Glands
Another distinct type of bump is a mucocele, a soft, fluid-filled swelling originating from the minor salivary glands beneath the cheek lining. These cysts form when a salivary gland duct is accidentally severed or blocked, causing mucus-like saliva to leak and pool into the surrounding connective tissue. The accumulation of this fluid creates a blister-like, dome-shaped lesion.
Mucoceles often appear blue or translucent due to the thin tissue covering the trapped fluid, distinguishing them from firmer fibromas. They usually range from one millimeter to two centimeters and are typically painless, though they can interfere with chewing and speaking. A characteristic feature is their tendency to spontaneously rupture, often while eating, only to reappear later as the gland continues to leak saliva.
While many mucoceles resolve naturally within a few weeks, persistent or frequently recurring lesions may require treatment. If the lesion does not heal within three to six weeks, a dental professional may recommend surgical removal, laser ablation, or cryosurgery. The procedure often involves removing the cyst along with the affected minor salivary gland to prevent recurrence.
Temporary Swellings Due to Infection or Inflammation
Bumps that appear quickly, cause significant pain, and are temporary are often the result of an acute infectious or inflammatory process. One common presentation is an aphthous ulcer, commonly known as a canker sore, which begins as a small, raised, painful bump before rupturing to form a crater-like lesion. These ulcers usually appear on non-keratinized surfaces like the inner cheek and are characterized by a painful, round or ovoid shape with a red border and a central yellowish-gray base.
Minor aphthous ulcers are self-limiting and typically heal without scarring within ten to fourteen days. Patients may experience a prodromal burning or tingling sensation in the area before the ulcer forms. Unlike chronic lesions, the pain and acute nature of canker sores usually signal an inflammatory response.
Another cause of a painful, temporary swelling is a localized abscess, which is a collection of pus caused by a bacterial infection. A cheek abscess may originate from a severe dental infection, such as an untreated cavity, where pus spreads from the tooth root into the surrounding soft tissue. These bumps are often red, swollen, warm, and tender to the touch, sometimes accompanied by fever or difficulty opening the mouth. Abscesses require prompt professional attention for drainage and antibiotics, as they will not resolve on their own and can spread infection.
When to Seek Professional Evaluation
While most oral bumps are benign, professional evaluation by a dentist or doctor is warranted for any lesion that exhibits concerning characteristics. It is recommended to seek a review for any bump or sore that persists for longer than two or three weeks. Lesions symptomatic of a potential problem will not resolve after the removal of obvious irritants, such as sharp foods or cheek biting.
Specific warning signs include rapid growth, a change in color or texture, or noticeable bleeding from the site. Other concerning symptoms are numbness, difficulty swallowing, or the presence of a firm lump that is fixed to the underlying tissue. A professional examination allows for proper diagnosis, and in some cases, a biopsy may be necessary to confirm the nature of the bump and rule out serious conditions, such as oral cancer.