Damage to other teeth: If an impacted wisdom tooth pushes against its neighboring tooth (the second molar), it may damage the other tooth or increase the risk of infection in that area. The pressure and pushing can also cause crowding or shifting of the other teeth, and may require orthodontic treatment to straighten other teeth if the bite and alignment are shifted.
Decay: Partially impacted wisdom teeth appear to be at higher risk of tooth decay (cavities) than other teeth. This is likely because wisdom teeth are harder to clean, being so far back in the mouth, and food and bacteria get easily trapped between the gum and a partially erupted tooth. This build up of food and bacteria often lead to chronic bad breath as well as cavities on both the wisdom tooth and the second molar.
Gum disease: Along with tooth decay, the difficulty of cleaning impacted, partially erupted wisdom teeth increases the risk of developing a painful, inflammatory gum condition called pericoronitis. This can lead to pain and swelling in or around the tooth, jaw or cheeks, and will likely continue to recur if not treated.
Cysts: A wisdom tooth develops in a sac within the jawbone. The sac can fill with fluid, forming a cyst that can damage the jawbone, teeth and nerves. Rarely, a tumor ( usually noncancerous or benign) develops. This complication may require removal of not just the tooth but also tissue and bone.