Comparison of three different intraoral anchorage systems used in canine distalization with pg retraction spring.

ABSTRACTThe aim of this thesis is to compare three different intraoral anchorage systems (mini-screw, TPA, banding of second molars) in canine distalization by using PG retraction spring and to analyse the effects of PG retractor spring on different anchorage units.For this aim, 45 patients who are in postpubertal period or completed growth, need maximum or moderate anchorage and first maxillary premolar teeth extraction were included in the study. Patients were divided into three groups according to the anchorage units as mini-screw (8 girls,7 boys), transpalatal ark (TPA) (10 girls,5 boys) and banding of second molars(13 girls, 2 boys). For canine retraction, PG retraction spring was used. Dental casts and cephalometric films were taken at the beginning (T1) and end (T2) of canine distalization. In order to evaluate the changes and the differences in cephalometric films and models, 28 parameters were used. For statistical evaluation; paired sample t-test was used to analyse the intragroup changes in canine distalization (T1-T2), variance analysis and LSD test were used to analyze intergroup differences and clarify from which groups these differences derive.In each three group, significant anchorage loss, more in TPA group and less in micro screw group, was found. Again the mesiopalatal rotation in molars was less in TPA group and more in micro screw group. Changes in monthly distalization speed and the total duration of distalization, distopalatal rotation, distal tipping and vertical movements were similar in all groups. The intergroup changes in these measurements of canines were similar to the other segmental arch systems including spring.Key Words: PG Retraction Spring, Canine Distalization, Anchorage, Mini-screw, TPA, Banding of second molar.