Teeth angulations after class II treatment with the Jones Jig followed by fixed appliances: A retrospective panoramic analysis.Int Orthod. 2020 Sep; 18(3):436-442.IO
The purpose of this study was to compare the maxillary mesiodistal dental angulations of Class II malocclusion patients treated with the Jones Jig, followed by fixed appliances, with normal values of a historical control group, on panoramic radiographs.
MATERIAL AND METHODS
The sample comprised 80 panoramic radiographs of 40 patients divided into two groups. Eligibility criteria included patients with predominantly dental Class II malocclusion; the presence of all teeth up to the second molars and no previous orthodontic treatment. The experimental group was composed of 60 radiographs of 20 patients treated with the Jones Jig distalizer followed by fixed appliances. The radiographs were taken at pre-treatment (T0), post-distalization (T1), and post-treatment (T2). The historical control group comprised 20 radiographs of 20 subjects with untreated normal occlusion. The mesiodistal axial angulations of all maxillary erupted teeth were evaluated with the Dolphin Imaging software. Intragroup comparisons in the experimental group were performed with repeated measures analysis of variance (ANOVA), followed by Tukey tests. The experimental group at T2 versus the control group were compared with t tests.
After distalization, significant distal angulation of the molars (110.58°±8.54, P<0.000) and mesial angulation of the second (86.43°±8.08, P<0.000) and first premolars (80.11°±8.01, P<0.000) was observed. However, this was corrected after comprehensive fixed orthodontics (100.54°±6.53; 98.95°±7.00; 94.92°±6.44; P<0.000, for these teeth, respectively). Intergroup comparisons resulted in first molars, premolars, canines, and central incisors significantly more distally angulated in the experimental group, when compared to the control.
In general, at the end of orthodontic treatment, patients treated with the Jones Jig distalizer followed by fixed appliances presented more distally angulated maxillary teeth when compared to an untreated group with normal occlusion.