Limited treatment options are available for young patients that have ankylosis of teeth after traumatic avulsion and re-implantation. Generally, we choose to treat these patients by extracting the ankylosed tooth prior to the patient entering their growth phases so as to minimize the potential bony defect. However, since many variables exist each situation must be evaluated individually to determine the most appropriate treatment option.
Take for instance the 14-year-old female in the photograph; she had a traumatic injury at the age of nine that caused her right central to be avulsed. What the literature reveals is that the longer the tooth is kept out of the mouth, the incidence of ankylosis increases dramatically. Ideally, the tooth should be re-implanted within 15-18 minutes to help decrease the chances of ankylosis. In this situation, the tooth was found and re-implanted within an hour.
Now, at age 14 it can be verified radiographically that the tooth has ankylosed as well as esthetically by comparing the discrepancies in the gingival margin and the incisal edge positions. The good news is the ankylosis is occurring at a very slow rate (this was verified by comparing radiographs and clinical images taken from the age of nine through the age of 14). What treatment options do we have for this patient?
What this patient currently has is an esthetic problem because of the discrepancies in the incisal edge and gingival margins. What we know is that at the age of 14, she is near the completion of her growth phase, meaning that most of the damage from the ankylosis and eruption during growth has already taken place. We've also established that although replacement resorption is occurring, it is occurring at a very slow rate.
In evaluating her smile line, it was noticed that she has a low smile line with less than average lip mobility. Her lip mobility was such that she didn't show the gingival margin of the teeth during either a posed or spontaneous smile. Given this information, the treatment option chosen was not to extract the tooth, but rather keep the tooth and add length to the incisal edge. Simply bonding composite or placing a veneer on the tooth will address the esthetic component in this case. The tooth can later be extracted and the ridge grafted for implant placement at any time (either after growth is complete or at a later date when the progression of the replacement resorption necessitates treatment).
What I hope you're realizing is that rather than just “extracting” the ankylosed tooth, many factors need to be taken into consideration when treating young patients that have undergone traumatic avulsion. We not only have to manage the site at the time of the trauma, but also continue to manage the area until the patient has reached an age suitable for implant placement whether the tooth has been extracted or maintained. However, it must be noted that depending on the age of the patient and the potential for growth, it is typically advisable to extract the tooth (or decoronate the tooth) before the patient enters their growth phase so as to minimize the potential bony defect.