In addition to complicated and uncomplicated tooth injuries, there are specific types of injuries classified by the damage caused by trauma. They include:

• Concussion. Minor injury to the periodontal ligament, which is a bundle of connective tissue fibers that anchors the teeth to the jaws. Typically, such injuries do not cause the tooth to be knocked out of alignment.
  
  
• Subluxation. Injury that causes a tooth to become loose in the socket but is not knocked out of position.
  
  
• Intrusive luxation. Injury that causes the tooth to be pushed deep into the socket, sometimes to the point that the tooth is no longer visible. The tooth may appear knocked out.
  
  
• Extrusive luxation. Injury that displaces the tooth from its position. These teeth require immediate treatment to keep them from becoming permanently fixed in this position.
  
  
• Avulsion. An injury that completely knocks a tooth out of place. Immediate replantation of the tooth is necessary to save it.