مقایسه زوایای tip و torque دندانها در بیماران پس از درمان ارتدنسی و افراد دارای اکلوژن نرمال

The angle of long axis of tooth crown is called tip in mesiodostal and&nbsp;torque in faciolingual direction. Both have special importance for producing&nbsp;an ideal occlusion. The aim of the present study was determination of the&nbsp;average tip and torque of each permanent tooth in well treated patients&nbsp;with edgewise system compare to control group with normal occlusion. In this study, 19 well treated cases through standard edgewise&nbsp;technique with non extraction strategy and 20 students of pre-university&nbsp;schools with normal occlusion according to IOTN were selected. Reference&nbsp;points and lines were marked on facial surface of each tooth on casts.&nbsp;Special device was designed for measuring the faciolingual and mesiodistal&nbsp;inclination of crowns. After 3 times measuring the tip and torque of teeth,&nbsp;student t-test and Kruskal &ndash; Wallis analysis were used for statistical analysis. The mean age of control group was 18.8 &plusmn; 0.5 year and in treated&nbsp;group was 20.3 &plusmn; 0.8. There was significant difference between mean of&nbsp;torque in control group and treated group for upper lateral incisor&nbsp;(4.75&plusmn;5.21 , 8.76&plusmn;5.82 respectively , p<0.03 ) . Also a significant difference&nbsp;was seen in average torque of lower second premolar between control&nbsp;group and treated one ( -23.48&plusmn;5.99 , -26.66&plusmn;4.64 respectively , p<0.05). &nbsp;&nbsp; There were no significant differences in tip of teeth between two groups. In&nbsp;comparison with Andrews study, in normal occlusion group, upper canine &&nbsp;first molar and lower lateral & first premolar had more buccal root torque.&nbsp; Except the torque of upper lateral incisor and lower 2nd premolar, &nbsp;&nbsp; torque and tip of other teeth had no significant difference.