Skeletal and dentoalveolar changes after extraction of the second molars in the upper jaw

The aim of this study was to evaluate treatment results after extraction of maxillary second molars. Since this therapy was chosen in patients with class II malocclusion, deep overbite and counterclockwise growth pattern, its effects on overbite and correction of the malocclusion were examined. For this purpose pre- and post-treatment models of 25 patients with 48 extracted upper second molars were measured and lateral cephalograms were appropriately superimposed in order to determine maxillary and mandibular skeletal and dentoalveolar changes. Our results indicate an average overbite reduction from 4.7 mm to 2.7 mm. None of the patients showed a posttreatment overbite increase. Despite the considerable initial Class II relation in many cases, a Class I occlusion was achieved in 92% of the patients. Primarily, the correction was achieved by distalization of the upper first molars. Furthermore, the mesial migration of the lower first molars, skeletal changes in the lower jaw, and the growth inhibition in the upper jaw contributed to the correction of the class II malocclusion.