ASYMMETRIC ROTATION OF UPPER FIRST PERMANENT MOLARS AND RELATIONSHIP WITH ARCH DISCREPANCIES

Abstract

Aim of the study: The aim of this study was to evaluate the rotation of the upper first permanent molars and the relationship with transverse and sagittal asymmetries of dental arch in patients with dental malocclusions. Material and Method: Thirty tree pairs of cast models were evaluated. Measurements were taken after the dental casts were scanned. The angle formed between a line crossing the mesio-buccal and mesio-palatal cusps of the right and left upper first molars and midsagittal plane were measured in all samples. The statistical evaluation of obtained data was done by descriptive statistics, Chi-square, Pearson Tests, Fischer exact tests. Results: In study group molar rotation had mean value 59.030 in right side and 58.200 in left side and the asymmetric rotation of molars was found in 58.49% patients and was more frequent in class I malocclusion (28%). Statistically significant associations were found between the asymmetric rotation of the upper first permanent molars and the Angle classes of malocclusion (p = 0.043) and with the sagittal asymmetry of the dental arch (p=0.019). Conclusions: The asymmetric upper first molars’ rotation is a common finding in orthodontic patients. The early evaluation and correction of the molars’ rotation in the start of orthodontic treatment allows to obtain a correct inter-occlusal sagittal molar relationship and space for an adequate eruption of permanent teeth.

Keywords

• ANGLE MALOCCLUSION
• MOLAR ROTATION
• SAGITTAL ASYMMETRY
• TRANSVERSE ASYMMETRY