Long-term evaluation of maxillary molar position after distalization using modified C-palatal plates in patients with and without second molar eruption.

<bold>Introduction: </bold>The purpose of this study was to analyze the treatment effects after molar distalization using modified C-palatal plates with and without second molar eruption and to evaluate the three-dimensional position of the molars during long-term retention using cone-beam computed tomography.<bold>Methods: </bold>The study sample comprised 74 third molars in 42 patients. Twenty-seven adolescent patients (mean age, 12.6 years) having 48 maxillary third molars were divided into 2 groups according to the eruption of their second molars: 15 patients with second molar eruption (group 1) and 12 patients without second molar eruption (group 2). Pretreatment, posttreatment, and long-term data (mean, 5.2 years) from cone-beam computed tomography were scanned and compared with control groups.<bold>Results: </bold>There was less tipping movement of the first and second molars (0.94° and 3.22°) and distal tipping movement of the third molars (8.91°) in group 1 than in group 2 (4.36°, 7.39°, and 3.08°, respectively), but the treatment time was shorter and the positional change of the third molars was insignificant in group 2. In the long-term, the second molars fully erupted after distalization in group 2, and there was no difference in the third molar position between group 1, group 2, and the control group, except for the vertical position of the third molars in group 1.<bold>Conclusions: </bold>In the long-term, the second molars fully erupted after distalization, and the third molars were in a favorable position. Therefore, these findings suggest that clinicians do not need to extract developing third molars before distalization in adolescents. [ABSTRACT FROM AUTHOR]