Cephalometric Effects of Class III Treatment: A Comparison of ORTATM and Protraction Facemask
Moore, Kristin N.
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Many appliances have been used to treat Class III malocclusion. Numerous studies have been completed on the effects of the protraction facemask but no study has evaluated the effects of the Orthodontic Removable Traction Appliance (ORTA). The purpose of this study was to determine whether treatment of Class III malocclusion with an ORTA had similar outcomes as a protraction facemask. Specifically, the objectives were 1) to compare the anterior movement of the maxilla, 2) to compare dental and skeletal effects, and 3) to compare effects on the mandible. This retrospective study evaluated the patients’ pre-treatment and post-treatment lateral cephalometric radiographs from 2 treatment groups. Each group consisted of Caucasian patients, ages 5 to 12 years with an initial diagnosis of a dental and skeletal Class III malocclusion. The radiographs were uploaded and traced with Dolphin software. Skeletal and dental measurements were taken in order to compare outcomes of the appliances. The results of this study showed that there were no statistical difference in skeletal and dental values at T1 and T2 between groups when comparing the ORTA and the protraction facemask in treatment of Class III malocclusion. This indicates that the initial severity of malocclusion was the same in both treated groups. A statistical difference was found in length of treatment between groups. The mean treatment time in the ORTA group was 6.96 months while the mean treatment time in the protraction facemask group was 10.96 months. Furthermore, there was no statistical difference in dental effects when comparing the ORTA and the protraction facemask in treatment of Class III malocclusion. The only statistically significant difference found between groups in skeletal effects was SNA. SNA was greater in the protraction facemask group when compared to the ORTA group. The mean increase in SNA was 0.456 degrees in the ORTA group and 1.812 degrees in the protraction facemask group. This demonstrates that the maxilla moved more anteriorly in the facemask group. These findings support the idea that the ORTA provides orthodontists with another useful Class III treatment modality.
orthodontic removable traction appliance
Class III malocclusion