الفهرس 
ENGLISH ABSTRACTOnly 14 pages are availabe for public view
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Abstract
This retrospective study was carried out to evaluate the effect of maxillary sinus proximity to maxillary molars root apices on molar angulation, inclination, rotation, root resorption and treatment time. It also aimed to assess the changes in maxillary molars angulation, inclination, rotation and root length before and after distalization movement.
Thirty-eight CBCTS and digital models pre-treatment (T0) and post-treatment (T1) were obtained from 19 adult patients who underwent maxillary molar distalization using Invisalign aligners (Align Technology, Inc., San José, CA, USA) with a minimum of 2mm distalization were evaluated in this study. At least 22 hours per day wear of the aligners was a main inclusion criterion. Sinus proximity and the changes in tip, torque, rotation, and root resorption were measured for 61 molars (183 roots).
Spearman coefficient analysis was used for assessing the correlation between sinus proximity and each of the other measured variables. Paired t-test was used to evaluate the differences between pre- and post-treatment readings. The level of significance was set at p ≤ 0.05. The intraclass correlation coefficient (ICC) assessed the reproducibility of measurements.
Results revealed an ICC with excellent reproducibility for linear and angular measurements. Spearman coefficient revealed a significant positive correlation between maxillary sinus proximity to root apices and molar inclination (buccal crown torque). Palatal root proximity to the sinus was the only individual root eliciting a positive correlation with molar inclination. No significant correlation was found between sinus proximity and molar angulation (tipping), rotation nor root resorption. Molar angulation did not show significant change after distalization however, there was significant increase in buccal molar inclination and mesiobuccal molar rotation. As regards root resorption; mesiobuccal, distobuccal and palatal mean root lengths significantly decreased with molar distalization using CAT, with a value that is considered clinically insignificant.