Impacted wisdom teeth occur when they grow in the wrong position due to insufficient space. Because the crown of the wisdom tooth covers the gums and the food debris and bacteria that accumulate between the gums, patients cannot properly clean it themselves. This untreated food and bacteria can lead to cavities in the wisdom tooth and adjacent teeth, making the periodontal tissues prone to inflammation (pericoronitis). This causes symptoms such as swelling and pain in the gums around the wisdom tooth, bad breath, swelling of the jaw lymph nodes, and even difficulty opening the mouth and pain when swallowing. To avoid various oral diseases, dentists will recommend extraction of impacted wisdom teeth.
Increased risk of tooth decay: Impacted wisdom teeth are often difficult to clean, easily accumulating food debris and bacteria, which can lead to tooth decay in wisdom teeth and adjacent teeth.

Swollen and painful gums: Impacted wisdom teeth are difficult to clean, leading to infection of nearby gums or periodontal disease, a condition known as "pericoronitis." Infection can cause symptoms such as red, swollen, and painful gums, bad breath, and pus discharge.

Tooth displacement: Impacted wisdom teeth may exert pressure on surrounding teeth, causing them to shift or become compressed.
Cyst formation: In some cases, cysts may form around impacted wisdom teeth. A cyst is a fluid or solid mass, and in some cases, impacted wisdom teeth can develop into dentigerous cysts or even invasive keratocysts. This can cause pain, swelling, and facial enlargement, and may require extensive bone resection for treatment.