Vertical periodontal ligament distraction--a new method for aligning ankylosed and displaced canines.

Objective: In the course of a clinical pilot study we tested the vertical periodontal ligament (V-PDL) distraction as a means of aligning ankylosed upper canines. The objective of this study was to analyze the appropriateness und effectiveness of this method.
Method and Materials: The ankylosed upper canines of five female patients aged between 16 und 19 years were surgically exposed, luxated, and after a latency period of 5 to 7 days, distracted at a rate of 0.5 mm per day. The installed distractors were borne by the periodontal-mucosa, the periodontal-mucosa and the bone, or by the bone exclusively. We evaluated the distraction distance and time and degree of hard and soft tissue generation present in the region surrounding the distracted teeth.
Results: All canines were aligned after a mean distraction period of 43.2 days (+/- 3.6 days). The mean distraction distance was 10.8 mm. Three canines had defects at the cemento-enamel junction, and one canine had to be extracted due to a large defect at the root.
Conclusions: Vertical PDL distraction is a minimally-invasive therapy to align ankylosed impacted canines. Even if the long-term prognosis of distracted canines with defects is uncertain, the patient benefits from the vertical PDL distraction because both hard and soft tissues are generated in the vicinity of the distracted canine.