Friction Versus Frictionless Mechanics During Maxillary En-masse Retraction in Adult Patients

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Friction Versus Frictionless Mechanics During Maxillary En-masse Retraction in Adult Patients With Class I Bimaxillary Dentoalveolar Protrusion: A Randomized Clinical Trial

Conditions
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En-masse Retraction , Class I Bimaxillary Protrusion

Intervention / Treatment
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* Device: Friction mechanics
* Device: Frictionless mechanics


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female adult patients with age range 18-30 yrs old. Class I bimaxillary dentoalveolar protrusion . Full permanent dentition. Good oral hygiene. Maximum anchorage is required. Healthy bone between first molars and second premolars is needed. Exclusion Criteria: Systemic disease. Severe crowding. Extracted or missing upper permanent tooth/teeth (except for third molars). Any signs or symptoms or previous history of temporomandibular disorders (TMD). Previous orthodontic treatment.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Friction mechanics<br>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<br>* 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.<br>* Other names: Nickel Titanium coil spring;|
| Active Comparator: Frictionless mechanics<br>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<br>* 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.<br>* Other names: T-loops archwire;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of retraction | months through clinical examination of the retracted anterior teeth | After complete retraction, average 9 months | 
| Rate of retraction | millimeters through dental models taken for each patient monthly at the follow up visit | 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 . | After complete retraction , average 9 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in incisors inclination | Degree and millimeter through lateral cephalometric analysis | After complete retraction, average 9 months | 
| Change in soft tissue profile | Degree and millimeter through lateral cephalometric analysis | After complete retraction, average 9 months | 
| molar anchorage loss | Degree and millimeter through lateral cephalometric analysis | After complete retraction, average 9 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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En-masse retraction , Class I bimaxillary protrusion