Ankylosis Part III: Treating Children With Ankylosed Permanent Teeth

As was mentioned in Ankylosis Part I and Part II, several factors need to be taken into consideration when deciding on the appropriate treatment option for an ankylosed tooth. When ankylosis is diagnosed in a child, these factors are even more important to evaluate prior to making the treatment decision.

These factors include:

• Whether the ankylosed tooth is deciduous or permanent
• The time/age of the onset of ankylosis
• The time/age at diagnosis
• Patient gender
• The location of the affected tooth
• The patient's smile line

Here we have a female patient that presented to the office at the age of 15 with tooth #8 ankylosed. (Figure 1)

This tooth was avulsed when she was 11 years old and re-implanted after being out of the mouth for approximately one hour. The desire of the patient and her family was to improve the esthetics. As you can see, the incisal edge and gingival margin are more apically positioned compared to the adjacent teeth.

The Ankylosis Patient

• The tooth most likely ankylosed at age 11 to 12
• The patient is now 15
• The patient is female

Prior to figuring out what we should do, there are still a few questions that we need to address:

• How fast is the resorption occurring? As can be seen from the radiographs that the patient brought, the rate of resorption seems to be progressing very slowly. (Figure 2)

• Where is the smile line? The patient has a very low smile line and does not show the FGM. (Figure 3)
• Where is she in relationship to her growth? Females generally are done growing at the age of 17. Given that she is 15 years of age now, it is anticipated that she is near the end of her growth phase.

Treatment Options and Concerns For the Ankylosed Tooth

The treatment options are:

• Extract the tooth and prepare for implant placement
• Subluxate the tooth and orthodontically reposition
• Use a segmental osteotomy to orthodontically reposition to the desired area
• Leave the tooth in its current position and restore the esthetics

If the tooth is extracted, she will need hard tissue augmentation, will have to wait until she is 17-years-old to have an implant placed, and we will need to provide an interim tooth replacement option throughout this time period. The downside of this option, as far as the ankylosis patient and her family are concerned, is that this is a very formidable time in her life. Managing appointments, schedules and interim tooth replacement would be difficult.

Subluxating the tooth and orthodontically repositioning it into the desired position will have limited success depending on how much of the tooth is ankylosed. This option typically works better on teeth that only have partial or spot ankylosis.

Using a segmental osteotomy to reposition the desired tooth can be successful depending on the surgical approach, but could be very problematic if necrosis of the segment were to occur.

What about leaving the ankylosed tooth for now and improving the esthetics by adding to the incisal edge? Will this create more problems? What we already know is:

• The replacement resorption is occurring slowly (so it could possibly be maintained for another 5-10 years)
• The patient is 15 and near the end of her growth phase (so the defect created by the ankylosis shouldn’t appreciably increase)
• The patient has a low smile (so you don’t see the gingival margin discrepancy)

Although the tooth could be extracted now in preparation for a single tooth implant, the decision was made to leave the tooth and restore the incisal edge length with composite. (Figure 4)

The ankylosis patient and her family knew that the composite was an interim restoration and that the tooth would require extraction and implant placement in the future. The question of when depends on the rate that the resorption progresses. In this patient, the tooth lasted another 10 years before it required extraction. (Figure 5)

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Gregg Kinzer, D.D.S., M.S., Spear Faculty and Contributing Author