Occlusal characteristics of Class II division 1 patients treated with and without extraction of two upper premolars*

Introduction: The purpose of this study was to identify initial occlusal characteristics of Class II, division 1 patients treated with and without extraction of two upper premolars. Methods: For this purpose, 62 patients presenting with Class II, division 1 malocclusion were selected and divided into two groups according to treatment type. Group 1 consisted of 42 patients (23 females and 19 males) with a mean age of 12.7 years, who were treated without extractions, with fixed appliance and headgear. Group 2 was composed of 20 patients (6 females and 14 males) with a mean age of 13.5 years, also treated with fixed appliance combined with the use of headgear, but Group 2 treatment plan indicated the extraction of two premolars. In order to observe initial and final occlusal characteristics as well as changes throughout treatment the Treatment Priority Index (TPI) was used. TPI values were subjected to statistical analysis by the independent t-test to compare variables between groups. Results and Conclusions: The results showed that the degree of initial malocclusion was different in the two groups when assessed by the TPI, which was higher in the group treated with extraction of two upper premolars.