Maxillary Skeletal Changes Concomitant With Different Levels of Force Application for Maxillary Protraction in Growing Class 3 Patients

Objective: to evaluate maxillary skeletal changes concomitant with different three levels of force application for maxillary protraction in growing orthodontiv patients with skeletal class 3 malocclusion. subjets and Methods: The current study was conducted on 30 class 3 patients (19 boys and 11 girls) with maxillary difficieny. The age of the recrutted sample ranged from 7-10 years. The patients were randomely allocated into three equal groups. The point of protraction force application varied among the three groups; groupA at the occlusal plane, group B 20 mm above the occlusal plane and group C at the infraorbital foramen. The duration of the treatment laste for 8 months, the patients were instructed to werethe appliance 16 hour/day with the applied 550gs protraction force. The analysis of the outcomes of this study was doneusing CBCT images were taken before and after maxillary protraction. Results: The average amount of maxillary advancement in the three groups 2.5mm with non-significant difference. The pattern of rotation accompanied with maxillary advancement as demonstrated by PP-TVP; in group A it was counterclockwise rotation (2.8 ̊ )in group B it was minimum (0.35 ̊) and in group C it was clockwise rotation (-1.8 ̊). Conclusions: Varying the point of force application was an efficient tool in order to control the rotation of the maxilla during protraction facemask therapy without affecting the amount of maxillary advancement.