Effect of maxillary and mandibular extrusion arches on dentoskeletal changes in adults with anterior open bite: a quantitative analysis.

OBJECTIVE: To quantify dentoskeletal changes accompanying the use of extrusion arches during the treatment of anterior open bite (AOB) in adults. MATERIALS AND METHODS: A total of 23 adult patients with an AOB of -3.05 mm +/- 1.27 mm were treated with upper and lower extrusion arches after the alignment phase. Lateral cephalograms were taken before placement of the extrusion arch, immediately after closure of the open bite (T2), and at the end of orthodontic treatment (T3). Data were statistically analyzed using repeated-measures analysis of variance and the Bonferroni post hoc test for pairwise comparisons (alpha = 0.05). RESULTS: Successful closure of AOB, with an overall change in overbite of 4.73 +/- 1.93 mm, was achieved in an average of 3.8 months and remained stable at T3. Upper and lower incisors were significantly extruded by 2.05 mm +/- 0.72 mm and 2.54 mm +/- 1.63 mm, respectively, and significantly retroclined by 6.36 degrees +/- 1.63 degrees and 8.45 degrees +/- 3.83 degrees , respectively, with a resultant increase in the interincisal angle of 12.80 degrees +/- 2.09 degrees . Statistically significant intrusion and mesial tipping (P < .001) of the maxillary and mandibular first molars were observed at T2. Dentoskeletal changes remained stable at T3, except for a significant reduction of the mesial tipping of the maxillary and mandibular first molars. CONCLUSIONS: The combined use of maxillary and mandibular extrusion arches resulted in significant favorable dentoskeletal changes that led to the successful closure of AOB during a short duration of treatment.