An interventional study of Friction mechanics and Frictionless mechanics in En-masse Retraction , Class I Bimaxillary Protrusion, sponsored by Cairo University. Status unknown. Open to participants aged 18 Years to 30 Years. Per ClinicalTrials.gov, last updated 2017-08-24.
Sponsored by Cairo University · Not applicable, Interventional, and Treatment
This study is a Randomized clinical trial comparing the effectiveness of two different mechanics during maxillary en-masse retraction in adult patients. Patients will be randomly divided into two groups:Friction and frictionless mechanics. Mini screws will be used in both group to ensure maximum anchorage during retraction. Lateral cephalometric radiographs and dental models will be taken for each patients pre and post -retraction. Following complete anterior segment retraction, the rate and duration of retraction will be evaluated for both groups as well as patient satisfaction with treatment. Changes in incisors inclination and soft tissue as well as anchorage loss will be also assessed.
Adult patients with Class I bimaxillary dentoalveolar protrusion will be recruited. All the patients need extraction of upper first premolars followed by anterior segment retraction and maximum anchorage.
The patients will be randomly allocated to one of two groups; either Friction or Frictionless group. In friction group, Nickel Titanium coil spring will be used for retraction of anterior segment while in frictionless group, T-loops will be used for retraction. All the patients will receive two miniscrews , one on each side to achieve maximum anchorage during retraction.
The patients will be seen on a monthly basis for follow up visit for activation of the appliance to maintain constant force during the study. An impression will be taken for the patients every visit, poured into stone for fabrication of dental models. The models will be used to monitor the rate of retraction of anterior teeth.
Every patient will be asked for lateral cephalometric radiograph before and after complete retraction. After data collection, two assessors will carry on the measurements blindly and independently. Statistical analysis of the data will be done and the results will be compared to evaluate the effectiveness of both techniques for en-masse retraction.
Exclusion Criteria:
Upper and lower arches will be bonded, leveled and aligned until reaching 0.019 x 0.025 st st archwires. Miniscrews will be inserted in the buccal alveolar bone between second premolars and first molars bilaterally. Miniscrews will be connected to the molar bands by rigid wire. Extraction of upper first premolars. Upper anterior teeth will be ligated together. Hook between upper laterals and canines will be fixed on the main archwire. Nickel Titanium coil spring ( friction mechanics of retraction)will be used for maxillary en-masse retraction by extending the spring from the hook to the molar bands. Re-activation of the coil spring will be done in the follow up visits to maintain a constant force through the study.
Device: Friction mechanics
Upper and lower arches will be bonded, leveled and aligned until reaching 0.019 x 0.025 st st archwires. Miniscrews will be inserted in the buccal alveolar bone between second premolars and first molars bilaterally. Miniscrews will be connected to the molar bands by rigid wire. Extraction of upper first premolars. Upper anterior teeth will be ligated together. T-loops retraction arch ( frictionless mechanics of retraction)will be used for maxillary en-masse retraction. The wire will be cinched distal to the molar bands. Re-activation of the retraction loops will be done in the follow up visits to maintain a constant force through the study
Device: Frictionless mechanics
Nickel Titanium will be extended from the hook between the lateral incisors and canines to the first molar bands, to allow frictional en-masse retraction of anterior segment.
Also known as: Nickel Titanium coil spring
T-loops retraction arch will be placed distal to the upper canines and cinched distal to the first molar bands, to allow frictionless en-masse retraction of anterior segment.
Also known as: T-loops archwire
Duration of retraction
months through clinical examination of the retracted anterior teeth
Time frame: After complete retraction, average 9 months
Rate of retraction
millimeters through dental models taken for each patient monthly at the follow up visit
Time frame: Average 9 months, recorded from the begin of retraction till the complete retraction of anterior teeth
Patient Satisfaction
Questionnaire will be filled by every patient at the end of the study regarding his experience and acceptance to the treatment, scale from 0 to 5 .
Time frame: After complete retraction , average 9 months
Change in incisors inclination
Degree and millimeter through lateral cephalometric analysis
Time frame: After complete retraction, average 9 months
Change in soft tissue profile
Degree and millimeter through lateral cephalometric analysis
Time frame: After complete retraction, average 9 months
molar anchorage loss
Degree and millimeter through lateral cephalometric analysis
Time frame: After complete retraction, average 9 months
No study locations are listed for this record.
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Plan to share: Undecided — Participant information won't be used outside the study except with written permission of the participant
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Cairo University