Wisdom teeth

      image taken from www.enginesystem.com
Wisdom teeth are the third and final set of molars that most people get in their late teens or early twenties. Sometimes these teeth can be a valuable asset to the mouth when healthy and properly aligned, but more often, they require removal. Wisdom teeth present potential problems when they are misaligned – they can position themselves horizontally, be angled toward or away from the second molars or be angled inward or outward. In addition, they can be entrapped completely within the soft tissue and/or the jawbone or only partially break through or erupt through the gum. Teeth that remain partially or completely entrapped within the soft tissue and /or the jawbone are termed "impacted."

The removal, or extraction, of wisdom teeth is generally recommended when:

The jaw isn't large enough to allow all the wisdom teeth to fully erupt in an alignment that is useful for chewing and crushing food.
Wisdom teeth only partially erupt. This allows an opening for bacteria to enter around the tooth and cause an infection, which results in pain, swelling, jaw stiffness, and general illness. Partially erupted teeth are also more prone to tooth decay and gum disease because their hard-to-reach location and awkward positioning makes brushing and flossing difficult.
Poor alignment of wisdom teeth crowds or damages adjacent teeth, the jawbone, or nerves. Wisdom teeth that lean toward the second molars make those teeth more vulnerable to decay by entrapping plaque and debris.
Cysts (fluid-filled sacs) form or to minimize their potential for forming. Cysts destroy surrounding teeth, jawbone, and nerves. If untreated, a tumor could develop from the walls of the cysts, requiring a more complicated surgical procedure for removal.