The sudden appearance of a lump or localized swelling in the inner cheek can be alarming. This “ball in the cheek” sensation is common, prompting concern because the cheek area contains a complex arrangement of muscle, salivary glands, and soft tissue. While many causes are minor and self-limiting, others require professional medical or dental attention. Understanding the characteristics of the swelling is the first step in determining its origin, which can range from simple trauma to infectious processes or structural issues.
Minor Injuries and Temporary Swelling
The most frequent causes of a cheek lump relate to simple mechanical trauma, often resolving spontaneously. Accidentally biting the inside of the cheek or lip, known as masticatory trauma, quickly creates localized swelling and inflammation. This injury causes fluid accumulation in the tissue, typically accompanied by immediate pain, but the swelling usually subsides within a few days as the tissue heals.
Another benign cause is an oral mucocele, a small, fluid-filled cyst that forms when the duct of a salivary gland is damaged or blocked. These cysts appear as soft, dome-shaped bumps, commonly on the inner cheek or lower lip, and are usually painless unless irritated. Mucoceles frequently rupture and drain on their own, disappearing and sometimes recurring until the underlying gland fully heals.
Canker sores, or aphthous ulcers, also present as painful lesions on the soft lining of the mouth, including the cheek mucosa. Unlike a mucocele, a canker sore is an open ulcer with a white or yellowish center and a red border, causing pain or a burning feeling. These ulcers are not contagious and tend to resolve within one to two weeks, with the pain diminishing as they heal.
Infections and Abscess Formation
A more serious cause of cheek swelling stems from infectious processes, particularly those originating from the teeth. A dental abscess, a pocket of pus caused by a bacterial infection, can lead to significant swelling projecting into the cheek tissue. If the infection is near the root tip (periapical) or in the gum (periodontal), the resulting pus can track through the bone and soft tissues, causing a noticeable and tender cheek mass.
The infectious mass is characterized by throbbing pain that can radiate to the ear or jaw, sensitivity to hot or cold temperatures, and sometimes a foul taste if the abscess is draining. Cellulitis is a related, widespread bacterial infection of the deeper skin layers and soft tissues of the face, presenting as a warm, red, and diffusely swollen area. This type of infection requires prompt intervention, often involving antibiotics and drainage, as untreated dental infections can spread rapidly to other areas of the head and neck.
Salivary Gland and Structural Causes
The cheek area houses major and minor salivary glands, and issues with these structures can manifest as a localized lump. The parotid gland, the largest salivary gland, is located in front of the ear and extends over the cheek. Inflammation of this gland is termed sialadenitis. This condition, typically due to bacterial or viral infection, causes painful, firm swelling in the cheek region that may be accompanied by fever and a foul-tasting discharge.
Another salivary gland problem is sialolithiasis, where calcified deposits (stones) form within the ducts, obstructing saliva flow. This blockage causes the gland to swell, with symptoms often worsening just before or during meals as the gland attempts to produce more saliva. Although more common in the submandibular gland, these stones can also affect the parotid gland duct, leading to intermittent cheek swelling until the obstruction is relieved.
Beyond the glands, the cheek contains the buccal fat pad, a mass of deep adipose tissue that acts as a cushioning layer. Benign tumors of this fatty tissue, such as a lipoma, present as a soft, slow-growing, and usually painless lump under the cheek skin. Fibromas, which are firm, smooth lumps resulting from fibrous tissue overgrowth, are also common in the inner cheek lining as a response to chronic irritation.
Urgent Symptoms and Seeking Medical Care
While many cheek lumps are benign, certain accompanying symptoms warrant immediate medical evaluation. Rapidly increasing swelling, especially if accompanied by difficulty breathing or swallowing, suggests a quickly spreading infection that could compromise the airway. A high fever, chills, or a general feeling of being unwell indicates a systemic infection requiring urgent treatment.
Any lump that persists without change for longer than one to two weeks should be examined by a healthcare professional, even if it is painless. A hard, fixed, or painless mass is particularly concerning and requires prompt investigation to exclude the possibility of a tumor, which, while rare, can occur in the salivary glands or soft tissues. Facial numbness or weakness on the same side as the swelling also necessitates an urgent medical consultation.