IADR Abstract Archives
Analysis of Orthodontic Treatment Outcomes with using 3-dimensional Digitizer
Objectives: The aim of this study was to compare the outcomes of maxillary dentoalveolar protrusion treated with 3 different anchorage system.
Methods: All patients were treated by retracting the maxillary dentoalveolar process using the extraction space of bilateral first premolars. They were subdivided into 3 groups according to the type of anchorage used. Group 1 (n=16) received a traditional anchorage preparation with a transpalatal arch and headgear; group 2 (n=15) received miniscrews; and group 3 (n=9) received miniplates for skeletal anchorage. We used a 3-dimensional (3D) digitizer to assess the positional changes of the maxillary teeth relative to the stable palatal rugous structures on the serial dental models. The 3D coordinates representing pretreatment and posttreatment maxillary dental casts were superimposed by investigating the positional changes of 18 landmarks.
Results: 3D analysis of dental models, in the buccopalatal, anteroposterior, and vertical directions, revealed significant differences in the amount of tooth movements between the headgear and the mini-implant groups. Both groups using skeletal anchorage had greater incisor retraction (6.9 mm for the miniscrew and 7.3 mm for the miniplate) than did the headgear group (5.5 mm).Tooth movements in the anteroposterior and buccopalatal directions did not reach a statistically significant difference between the headgear and miniscrew groups, whereas the maxillary posterior teeth of the cases receiving miniplates showed greater intrusion than those receiving miniscrews anchorage.
Conclusions: This 3D analysis through serial dental models demonstrated that compared to headgear, skeletal anchorage achieved better performance in the treatment of maxillary dentoalveolar protrusion and significant intrusion of the maxillary posterior teeth was noted in the miniplate group. Greater retraction of the maxillary anterior teeth, less anchorage loss of the maxillary posterior teeth, and the possibility of maxillary molar intrusion all facilitated correction of the Class II malocclusion, especially for cases with a hyperdivergent face.
Methods: All patients were treated by retracting the maxillary dentoalveolar process using the extraction space of bilateral first premolars. They were subdivided into 3 groups according to the type of anchorage used. Group 1 (n=16) received a traditional anchorage preparation with a transpalatal arch and headgear; group 2 (n=15) received miniscrews; and group 3 (n=9) received miniplates for skeletal anchorage. We used a 3-dimensional (3D) digitizer to assess the positional changes of the maxillary teeth relative to the stable palatal rugous structures on the serial dental models. The 3D coordinates representing pretreatment and posttreatment maxillary dental casts were superimposed by investigating the positional changes of 18 landmarks.
Results: 3D analysis of dental models, in the buccopalatal, anteroposterior, and vertical directions, revealed significant differences in the amount of tooth movements between the headgear and the mini-implant groups. Both groups using skeletal anchorage had greater incisor retraction (6.9 mm for the miniscrew and 7.3 mm for the miniplate) than did the headgear group (5.5 mm).Tooth movements in the anteroposterior and buccopalatal directions did not reach a statistically significant difference between the headgear and miniscrew groups, whereas the maxillary posterior teeth of the cases receiving miniplates showed greater intrusion than those receiving miniscrews anchorage.
Conclusions: This 3D analysis through serial dental models demonstrated that compared to headgear, skeletal anchorage achieved better performance in the treatment of maxillary dentoalveolar protrusion and significant intrusion of the maxillary posterior teeth was noted in the miniplate group. Greater retraction of the maxillary anterior teeth, less anchorage loss of the maxillary posterior teeth, and the possibility of maxillary molar intrusion all facilitated correction of the Class II malocclusion, especially for cases with a hyperdivergent face.