Dentoalveolar effects produced by different appliances on early treatment of anterior open bite: A randomized clinical trial.

OBJECTIVES: To compare different appliances for early anterior open bite (AOB) correction. MATERIALS AND METHODS: This was a parallel, randomized clinical trial. A prospective sample of patients with AOB was recruited consecutively. Eligibility criteria included angle class I malocclusion with AOB equal to or greater than 1 mm. Participants were allocated by simple randomization to 4 groups: bonded spurs, chin cup, fixed palatal crib, and removable palatal crib. Dentoalveolar changes among the groups were assessed by blinded observers by comparing lateral cephalograms taken before (T1) and 12 months after treatment (T2; analysis of variance followed by Tukey test). Of the measurements, 30% were reassessed for reliability (intraclass correlation coefficient and Bland-Altman agreement test; α = 5%; 95% confidence interval). RESULTS: A total of 99 patients with a mean AOB of 3.7 mm (mean age 8.4 ± 0.8 years, both genders) were recruited. Dropouts occurred in all the groups, yielding a final sample size of 81 analyzed individuals. Intergroup comparisons of differences (T2-T1) showed significant differences for the incisor positioning variables (1.1, 1-PP, 6-PP, IMPA, 1.NB and 1-GoMe). However, there was no significant difference in AOB reduction among the groups, with an average correction of 3.1 mm. CONCLUSIONS: All of the tested devices promoted dental changes, especially in the anterior region, and contributed to AOB reduction during the study period. However, fixed palatal crib demonstrated greater impact on the positioning of the incisors.