Orthodontic retention--three methods trialed.

Abstract

Single centre randomised controlled trial. Patients treated by a single orthodontist were randomised to one of three retention methods: removable vacuum-formed retainer (VFR) covering the palate and the maxillary anterior teeth from canine-to-canine and bonded canine-to-canine retainer in the lower arch (group V-CTC); maxillary VFR combined with stripping of the lower anterior teeth (group V-S); prefabricated positioner covering all erupted teeth in the maxilla and the mandible (group P). All retention appliances were provided within one hour of debonding. Dental study casts were taken before treatment, at appliance removal and five years or more out of retention. Little's irregularity index, intercanine and intermolar width, arch length and overbite/overjet were recorded. Twenty-five patients were randomised to each group with 69 completing the two-year retention period (24 in V-CTC group; 23 in V-S group; 22 in P group). Forty-nine patients were available five years post retention (16 in V-CTC group; 17 in V-S group; 16 in P group). No significant differences were found between the groups. After five years or more out of retention, the three retention methods had achieved equally favourable clinical results. Thus a maxillary VFR combined with a bonded canine-to-canine retainer in the mandible, a maxillary VFR combined with stripping of the mandibular anterior teeth and a prefabricated positioner can all be recommended.