Two interceptive approaches to palatally displaced canines: a prospective longitudinal study.

This study evaluated the effectiveness of two interceptive approaches to palatally displaced canines (PDCs), ie, extraction of the deciduous canines alone and in association with the use of a cervical pull headgear. The prospective longitudinal design of the investigation included 46 subjects with PDC (62 maxillary canines) who were randomly assigned to one of three groups (1) a group that underwent the extraction of the deciduous canine only, (2) a group that received in addition the use of a cervical pull headgear, and (3) an untreated control group. Panoramic radiographs were evaluated at initial observation (T1) and after an average period of 18 months (T2). Cervical vertebral maturation was assessed on lateral cephalograms at T1. Successful or unsuccessful canine eruption was assessed 48 months after T1. The between-group statistical comparisons were performed on the T1-T2 changes in the diagnostic parameters on panoramic radiographs, the prevalence rates of successful canine eruption, and the amount of time for canine eruption. The removal of the deciduous canine as an isolated measure to intercept palatal displacement of maxillary canines showed a prevalence rate of 50% success, which was not significantly greater than the success rate in untreated controls. The use of a headgear in addition to the extraction of the deciduous canine induced successful eruption in 80% of the cases, with a significant improvement in the measures for intraosseous canine position. There was no significant difference between the two interceptive approaches in the time required for canine eruption.