Impacted wisdom teeth

DEFINITION

Impacted wisdom teeth are third molars at the back of the mouth that don’t have enough room to emerge or develop normally.

Wisdom teeth are the last adult teeth to come into the mouth (erupt). Most people have four wisdom teeth at the back of the mouth — two on the top, two on the bottom.

Impacted wisdom teeth can result in pain, damage to other teeth and other dental problems. In some cases, impacted wisdom teeth may cause no apparent or immediate problems. But because they’re hard to clean, they may be more vulnerable to tooth decay and gum disease than other teeth are.

Impacted wisdom teeth that cause pain or other dental complications are usually removed. Some dentists and oral surgeons also recommend removing impacted wisdom teeth that don’t cause symptoms to prevent future problems.

CAUSES

Wisdom teeth (third molars) become impacted because they don’t have enough room to come in (erupt) or develop normally.

Wisdom teeth usually emerge sometime between the ages of 17 and 25. Some people have wisdom teeth that emerge without any problems and line up with the other teeth behind the second molars. In many cases, however, the mouth is too crowded for third molars to develop normally. These crowded third molars become trapped (impacted).

An impacted wisdom tooth may partially emerge so that some of the crown is visible (partially impacted), or it may never break through the gums (fully impacted). Whether partially or fully impacted, the tooth may:

• Grow at an angle toward the next tooth (second molar)
• Grow at an angle toward the back of the mouth
• Grow at a right angle to the other teeth, as if the wisdom tooth is “lying down” within the jawbone
• Grow straight up or down like other teeth but stay trapped within the jawbone

SYMPTOMS

Impacted wisdom teeth don’t always cause symptoms. However, when an impacted wisdom tooth becomes infected, damages other teeth or causes other dental problems, you may experience some of these signs or symptoms:

• Red or swollen gums
• Tender or bleeding gums
• Jaw pain
• Swelling around the jaw
• Bad breath
• An unpleasant taste in your mouth
• Difficulty opening your mouth

When to see a doctor

See your dentist if you experience symptoms in the area behind your last molar that may be associated with an impacted wisdom tooth.