الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
The current study was a Randomized Controlled Trial that was performed to investigate three dimensionally, using Cone Beam Computed Tomography imaging, the effect of Miniplates assisted maxillary posterior segment intrusion on skeletal, dental and soft tissue changes in Class II hyperdivergent adolescents.
Sample size calculation was carried out and resulted in enrolment of 20 patients requiring intrusion of maxillary posterior segment due to increase in the dento-alveolar height of upper posterior segment. The sample was recruited from the outpatient clinic of the Orthodontic Department, Faculty of Dentistry, Cairo University. The sample was randomly divided into two groups; an intervention group and a control group to roll out the growth factor.
After cementation of a trans-palatal arch away from palate by 5mm and placement of a passive wire of 0.017”× 0.025” stainless-steel in the upper posterior fixed orthodontic appliance. Surgical placement of the miniplate in the zygomatic arch then after 3 weeks an intrusion force of (250-300)gm was applied using NiTi closing coil spring. The lower posterior teeth was reinforced by a passive stainless steel wire to prevent its over eruption.
Data were collected from pre and post maxillary intrusion CBCT imaging. A questionnaire was given to each patient first day after surgery then after one week and finally after intrusion of posterior segment. The assessed outcomes were the improvement of the total and lower facial heights, the 3D skeletal and dental effect, the amount of posterior segment intrusion, tipping, torque , posterior segment root resorption and finally the pain related to miniplate placement procedure and its effect on different daily activity. Statistical analysis was performed on the gathered data and results were withdrawn.
Paired sample t test for pre and post comparison within each group and independent sample t test for comparing the changes post-pre between groups. For not normally distributed variables Wilcoxon signed rank test was applied.
from the results of the clinical and statistical analyses, and within the limitations of this study, the following conclusions could be drawn:
1. Intrusion of posterior segment using miniplates was able to significantly improve the anterior facial height and decrease the interlabial gap.
2. Mandibular anticlockwise rotation was found which accompanied by significant improvement of the facial convexity.
3. Overjet was decreased significantly while overbite had a significant increase after molar intrusion.
4. Using miniplate was effective in intruding the posterior segment which was statistically significant.
5. Despite using a transpalatal arch molars showed buccal rolling with a non-significant mesio- distal tipping.
6. Patients of the intervention group experienced pain which was comparable to the anesthesia injection during miniplate insertion however it was minimal after one week.
7. Swelling was the chief complaint after the surgery which lasted 5 days in average.
8. All the patients in the intervention group was satisfied by the treatment and about 90% would recommend the same kind of treatment to their relatives.