Extraction therapy in patients with Class II/2 malocclusion.

The aim of this study was to analyze the dynamic development of Class II, Division 2 malocclusion with reference to the untreated patients from the Belfast Growth Study. As a second step, the influences of premolar extraction in all 4 quadrants and of maxillary second molar extraction in the upper jaw in Class II/2 patients were examined, focusing on the cephalometric variables in comparison to those of the untreated patients from the Belfast study. The longitudinal cephalometric values of 20 patients in each group were compared. In addition, the possibility of third molar eruption was evaluated in the extraction patients from the panoramic radiographs. The overbite based on study models at the beginning and end of treatment was calculated. Furthermore, renewed spacing after premolar extraction was assessed. The results derived from cephalometric analysis demonstrated that profile flattening was also observed in untreated Class II/2 patients during the growth period. Comparison of these data with those obtained from the extraction groups revealed a significantly marked recession of the upper lip after premolar extraction. In contrast, only slightly increased flattening after maxillary second molar extraction was observed compared with the untreated patients of the control group. Whereas the interincisal angle was reduced to a value approximating that of untreated Class I patients after maxillary second molar extraction, only a small decrease was recorded after premolar extraction. From our point of view, the claim that premolar extraction facilitates third molar eruption should be seen in an extremely critical light and should not contribute to the decision in favor of extraction. In addition, there is a problem of renewed spacing in the extraction area after premolar extraction.