En masse retraction of anterior teeth through rapid periodontal distraction by a retraction screw: A randomized control trial.

BACKGROUND

Rapid distraction of the periodontal ligament is an effective method to shorten the orthodontic treatment time. The objectives of the present study were to assess the effects of an HYCON device (Adenta GmbH, Germany) on the rate of en masse retraction of the anterior teeth, duration of retraction, anchorage loss, root resorption, and soft tissue changes.

METHODS

This study was conducted on 60 female patients aged >18 years, divided randomly into two equal groups: Group 1 comprised 30 patients with HYCON, and group 2 comprised 30 patients with nickel-titanium closed coil springs. Skeletal, dental, and soft tissue changes were evaluated on pre- and post-retraction lateral cephalograms, and the rates of anterior tooth movement and anchorage loss were assessed monthly on the dental casts of the patients. Root resorption was assessed using intraoral periapical radiograph. Student's t test was used for the analysis of parametric data, and the Mann-Whitney U test was used for nonparametric data.

RESULTS

HYCON significantly shortened the retraction duration by 3 months. The rate of anterior teeth retraction was two times faster in group 1, compared with group 2. There was a significant difference in the anchorage loss between the groups in only first 2 months of treatment. Group 2 showed significantly more root resorption and soft tissue changes than group 1 (P < 0.05).

CONCLUSIONS

HYCON is an effective device for significantly shortening the duration of retraction with anchorage loss of 2 to 2.5 mm. However, careful monitoring for possible root resorption should be performed.