Treatment stability after total maxillary arch distalization with modified C-palatal plates in adults.

Introduction: The purpose of this study was to evaluate skeletal, dentoalveolar, and soft tissue changes at 3 years posttreatment in patients with Class II Division 1 malocclusion treated with modified C-palatal plates (MCPPs).

Methods: The sample consisted of 69 lateral cephalograms of 23 patients Class II Division 1 malocclusion (9 men, 14 women; average age, 20.1 years) who underwent bilateral distalization of their maxillary dentition. The lateral cephalograms were taken immediately before the placement of the MCPPs (T1); at the end of orthodontic fixed appliance therapy (T2); and at the posttreatment observation period (3 years posttreatment; T3). Twenty-three variables were measured. Repeated measures ANOVA followed by post hoc analysis using Bonferroni test was used to identify significant differences between time points.

Results: Maxillary first molars showed a distal movement of 3.44 ± 1.08 mm (P <0.001) distal crown tipping of 2.35° ± 6.74°, and intrusion of 1.42 ± 1.12 mm from T1 to T2. However, from T2 to T3, there was an average of 0.41 ± 0.25 mm of mesial movement, 0.50 ± 0.46 mm of extrusion, and insignificant mesial crown tipping (0.92° ± 2.46°; P = 0.06). The nasolabial angle increased 9.36° ± 6.04° from T1 to T2 (P <0.001) but then decreased 1.55° ± 1.54° from T2 to T3.

Conclusions: MCPPs are a viable treatment option for maxillary total arch distalization with minimal changes in treatment effects 3 years posttreatment.