engleski

Long-term rotational changesof anterior teeth 20 years posttreatment

AIM: to investigate rotational changes of upper and lower anterior teeth 20 years after orthodontic treatment. MATERIALS AND METHODS: Sample was consisted of 103 patients (73 female and 30 male), with class I and class II malocclusions. 48 patients were treated nonextraction and 55 were treated with premolar extractions. All patients were treated with fixed orthodontic appliances by one experienced orthodontist. Retention period lasted for 3 years. Dental casts were obtained before treatment (T1), after treatment (T2) and at long-term postretention period (T3). They were scanned with Ortho Insight 3D Scanner (Motion View LLC, Hixon, USA). Using custom software developed in Matlab programing environment, rotational angles (RA) of upper and lower 6 anterior teeth were measured in 3 periods. RESULTS: Rotational angles in nonextraction cases showed slightly higher initial values than extraction. Only RA of teeth 13, 12, 33, 41, 42, 43 show statistically significant difference based on treatment modality (ANOVA). CONCLUSION: Long-term rotational changes were stable 20 years posttreatment in both extraction and nonextraction cases with postretention changes of only 1-3 degrees.

rotation ; long-term changes ; orthodontics

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