engleski

EVALUATION OF ARCH WIDTHS AS PREDICTORS FOR LONG TERM STABILITY AFTER ORTHODONTIC TREATMENT WITH AND WITHOUT EXTRACTIONS

Aim: To establish predictors of long term stability after orthodontic treatment with and without extractions. Materials and methods: Retrospective study comprised dental casts from 103 patients with Class I and II malocclusions treated with comprehensive orthodontic treatment with fixed appliances. Sample was collected from private orthodontic office's database in Arlington, USA and treated by one experienced orthodontist. Casts were obtained in 3 stages: pretreatment (T1), posttreatment (T2), and long term postretention (T3), digitalized with 3D scanner and converted to STL files. Intercanine width(IK), intermolar(IM) width, Little irregularity index(II) were evaluated in Mathlab software for upper and lower arches. Results: Class I in 71.8% of cases and class II in 28.2%. Average postretention time was 17.2±6.5 years with average retention time 3.4±1.17 years. Extraction was performed in 55 patients while 48(46.6%) received nonextraction treatment. Bonferroni Post Hoc test showed that average II in upper and lower arch in T1 was statistically significant higher in extraction group (p=0, 001). In T3 in upper and lower arch II was slightly higher in extraction cases, but remained under 2.05mm. II T3 in upper and lower arch showed negative correlation with IM T3 in upper arch (Pearson, N=103, p=0.047), while IK in upper and lower arch in T3 correlate with IM T3 in upper and lower (N=103, p=0, 000) Conclusion: Clinically relevant long term stability under 3 mm was found in extraction and nonextraction cases in upper and lower arches. Intermolar width and its change during orthodontic treatment can be a good predictor of stability in extraction cases.

stability, dental arch, width

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