The word impaction, when referring to teeth, means a tooth that is blocked, stuck, or for any other reason fails to fully erupt to be functional. The most commonly impacted permanent (adult) teeth are the 3rd molars, otherwise known as wisdom teeth. The second most common teeth to be impacted are the upper canines, otherwise known as “eye teeth” owing to their anatomic position directly below the eyes. Upper canines normally erupt into full position around the age of 13. Unlike 3rd molars, which serve a very limited to no functional role, canine teeth have very significant functional roles. Canines are thought of as the cornerstone of peoples’ smile, they are the last teeth of the “esthetic 6”. Canines have the longest root of any tooth in the mouth, and thus serve as an important foundation to the spacing and alignment of the rest of the teeth in that jaw. When chewing food, the canine teeth, because of their length and position are normally the first teeth to touch and bite into food.
While upper canines are in fact the second most commonly impacted teeth behind wisdom teeth, it is still considered rare, with an incidence in the U.S. population of approximately 2%. Impacted canines are far more common in females than in males. There are some well-documented causes of canine impaction. Failure of the primary tooth or baby canine to be appropriately lost is one of the most common reasons for upper canine impaction. Improper jaw growth, leading to inadequate space to accommodate all the adult teeth, the canine then often is the tooth that is displaced and blocked from erupting. If there is a pathologic process in the area of the upper canine, such as a cyst, this may block the canine and its proper eruption path. There are many cases however, where there is no identifiable reason that the canine tooth is impacted.
Impacted canines, once identified, are usually observed for a period of time to assess for any progression. This is done by routine x-rays and clinical exams. Normally the second step in treatment of impacted canines is addressing the possibility of the baby canine obstructing the eruption, this is done by extraction of the baby canine tooth. If extraction of the baby canine, or relief of any other obstruction to eruption does not allow for progress in the eruption of the upper canine, the next treatment to consider is orthodontic traction to force eruption, a procedure commonly referred to as an exposure and bonding. This procedure is performed by an oral surgeon, normally under sedation in the office setting. The impacted tooth is accessed by moving the gum tissue out of the way and fully exposing the crown of the tooth. Once exposed, a traction appliance, normally a bracket with an attached chain is bonded to the tooth with composite material. This appliance will then be used to add light traction force to the impacted tooth to help guide it into position over time. Expose and bond procedures are most effective if performed prior to complete root formation of the canine tooth. Failure of the canine tooth to properly erupt following a course of treatment indicates the tooth for extraction. The reason to consider extraction of an impacted canine that fails treatment is because there is increased risk of development of cysts or other pathologic lesions around the impacted tooth.
Planning and treatment of impacted teeth, including third molars and canines is best initiated by one’s general dentist, and often involves evaluation by an orthodontist and possibly an oral surgeon.