Evaluation of the Rate of En-masse Retraction in Orthodontic Patients With Maxillary Protrusion

Study Overview
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Brief Summary
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There's a scarcity in literature concerning en-masse retraction and its effect on the rate of tooth movement. The purpose of this study is to determine, In orthodontic patients with maxillary protrusion, which form of mechanics in en-masse retraction offers a faster rate of retraction; Friction or Frictionless Mechanics.

Detailed Description
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The en-masse technique can be done in one of two ways: through friction or frictionless mechanics. Both are viable options, but, ideally, we want to retract and complete the orthodontic treatment as quickly as possible, in order to decrease the negative effects that may occur during treatment. Which of these mechanics results in a decreased treatment time is still up for debate.

Official Title
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Evaluation of the Rate of En-masse Retraction in Orthodontic Patients With Maxillary Protrusion Using Friction Versus Frictionless Mechanics: A Randomized Clinical Trial

Conditions
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Bimaxillary Protrusion

Intervention / Treatment
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* Procedure: Power chain and Crimpable hook for En-Masse Retraction
* Procedure: T- Loop


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults and Adolescent patients (both genders) Age range (14-24) Patients with maxillary protrusion requiring first premolars extraction (Bimaxillary Protrusion or Class II division 1 cases). Patients with fully erupted permanent teeth (not necessarily including the third molar). Cases requiring maximum anchorage during retraction. Good general and oral health Exclusion Criteria: Patients suffering from any systemic diseases interfering with tooth movement. Patients with extracted or missing permanent teeth. (except for third molars). Patients with badly decayed teeth. Patients with any parafunctional habits (i.e. Bruxism, tongue thrusting, mouth breathing, etc…). Patients with previous orthodontic treatment

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 24 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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 |
| --- | --- |
| Experimental: En-Masse Retraction using sliding mechanics (Friction)<br>6 anterior teeth (en-Masse) retracted using a crimpable hook distal to the upper lateral incisor and a power chain | Procedure: Power chain and Crimpable hook for En-Masse Retraction<br>* Retraction will start on a 0.017x0.025 Stainless steel wire using elastomeric chain (force applied will be 212 g per side) extending between the crimpable hooks and the miniscrew<br>|
| Experimental: En-Masse Retraction using segmental mechanics (Frictionless)<br>6 anterior teeth (en-Masse) retracted using a T- loop | Procedure: T- Loop<br>* Closing retraction T-loops will be fabricated using 0.017 x 0.025 TMA wire. The loop will be positioned halfway the extraction space and the canine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retraction Rate | The antero-posterior movement of anterior teeth and first molars will be assessed by measuring the digitilized study models taken of the patients monthly (measured in mm) | From pre to post retraction (an average of 6 - 8 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anchorage Loss | Digitilized dental models taken before and after the completion of retraction will be measured by identifying landmarks and reference lines and planes (measured in mm) | From pre to post retraction (an average of 6 - 8 months) | 
| Molar Rotation | Study models that are taken pre and post retraction (then digitilized) will be used to assess the rotation of the maxillary first molars in relation to a reference line (measurement of the angles in degrees) | From pre to post retraction (an average of 6 - 8 months) | 
| Pain of intervention | Each patient will fill a questionnaire regarding his treatment experience in a VAS scoring from 1-10 | From pre to post retraction/intervention (an average of 6 - 8 months) | 
| Anterior teeth torque, extrusion/intrusion | The principle investigator will examine pre and post lateral cephalometric radiographs in relation to lines and reference planes (measurements in degrees and mm) | From pre to post retraction (an average of 6 - 8 months) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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En-masse Retraction, Friction, Fricitionless, Lateral Cephalometric, Rate, Dental Models