Comparison of orthodontic treatment duration and Peer assessment index scores of class II patients

The purpose of this retrospective study was to evaluate and compare the treatment duration and occlusal effectiveness of the nonextraction and extraction treatment protocol in patients with Class II malocclusion. The records of 157 Class II patients were collected from the archive of Orthodontic Department of Yeditepe University. The patients were allocated into two groups regarding treatment modality. The nonextraction group was composed of 81 patients (42 females, 39 males) with a mean age of 12.5±2.5 years and the extraction group was composed of 76 patients (25 females, 51 males) with a mean age of 14.5±3.7 years. Pre- and post-treatment dental models were evaluated using Peer Assessment Rating index (PAR) and the treatment duration was noted. Initial PAR (iPAR), final PAR (fPAR), PAR difference (DifPAR), percentage PAR reduction (PcPAR) and treatment efficiency index (TEI) were calculated. Pretreatment cephalometric measurements were performed. The data was statistically evaluated. In both groups, mean fPAR scores were statistically significantly lower than the mean iPAR scores (p<0.001). There was no statistically significant difference between groups in DifPAR, PcPAR, TEI and treatment duration (p>0.05). However, fPAR of the extraction group were statistically higher compared to that of the nonextraction group (p<0.05). In the extraction group, the boys showed higher treatment duration and iPAR scores compared to the girls (p<0.05). There was a significant and positive correlation between iPAR and fPAR as well as PcPAR. No significant correlations were revealed between cephalometric variables and PAR scores. Nonextraction and extraction treatment of Class II malocclusion showed similar occlusal improvement, treatment efficiency and duration. The initial severity of the malocclusion seems to affect the final outcome but has no influence on treatment duration.