Effects of buccal mini screw support on upper first permanent molars during palatally bone anchored distalization

The aim of this study is to compare the effects of additional buccal force supported by a mini screw to premolar anchorage during the distalization of upper first molars with palatal bone anchorage with two palatal mini screws.Study was carried on 24 subjects with bilateral Class II molar relation. Mean age was 15.7 years at the beginning of the study and mean distalization period was 0.68 years. Palatal force was induced by NİTİ open coils on a 0.9 mm palatal arch fixed to two palatal mini screws. Additional buccal force was induced by modified lokar appliance supported with a buccally placed mini screw on one side; NİTİ open coils placed on a segmental arch wire was extended from the tube with a step-down bend soldered to the premolar band and palatal arch on other side. Total buccal and palatal forces applied to the upper first molars were 200 grams. Nineteen angular, 26 linear measurements on lateral sefalograms; 2 angular and 15 linear measurements on upper orthodontic model photocopies taken at beginning and after distalization were evaluated. Paired t test and Wilcoxon test in intragroup comparison, student t test in comparison of left and right sides were used.Regarding to the distalization of the upper molars no significant difference was found between the methods on two sides where distal movement of the upper first premolars were significantly different.As a result, there was no significant difference found in additional buccal force supported by a mini screw compared to premolar anchorage during the distalization of upper first molars with palatal bone anchorage with two palatal mini screws. However, on the side where additional buccal force supported by a mini screw distal movement of the first premolars were not restricted providing a decrease in the total treatment time.