Comparison of the effects of CNA mushroom loop and compound retraction arcwires on dentofacial structers

ABSTRACT Comparison of the Effects of CNA Mushroom Loop and Compound Retraction Archwires on Dentofacial Structers The aim of this study was to investigate and compare the effects of the "CNA Mushroom Loop" and "Compound Retraction Archwires" on dentofacial structures. Thirty patients were included in this study. In order to retract four upper incisors, "CNA Mushroom Loop" (Group I) was applied to 15 patients with an average age of 15.7±0.7 and "Compound Retraction Archwire" to 15 patients with an average age of 16.4±1.1. From all the subjects, lateral cephalograms, periapical radiographs and intra-extra oral photos were taken at initiation and at end of the retraction procedure. On average, upper incisor retraction time (T2-T1) for Group I and II were 161±33 and 215±53 days, respectively. Although "CNA Mushroom Loop" archwire had no skeletal effect, the A point was replaced sagitally and vertically in "Compound Retraction Archwire" group. In group I, on avarage, the upper first molars moved 1.4mm forward, the upper incisors tipped 5° lingually and intruded lmm. In group II, on average, the upper first molars moved 1.4 mm forward and the upper incisors showed parallel movement lingually. In both group, there was no statistically significant effect on profile. In the first group, the root resorption of laterals was 0.8±1.0mm and of centrals l.l±l.lmm, on average. In the second group, the root resorption of laterals was 1.3±1.6mm and of centrals 0.6±1.5mm, on average. There was no statistically significant difference for root resorption of upper incisors between the 2 groups. Consequently, each archwire constitutes different movements on upper incisors. The amount of anchorage loss in the posterior segment is almost the same in both groups. Also, there is no statistically significant difference between the first and second group on soft tissue profile and root resorption. Key Words: "CNA Mushroom Loop", "Compound Retraction Archwire", upper incisor retraction, paralel movement, anchorage, root resorption, soft tissue profile. XIV