Evaluation of the Rate of Anterior Segment Retraction Using Two Types of Mechanics

Study Overview
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Brief Summary
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The rate of anterior segment retraction in bi-maxillary protrusion cases was evaluated comparing the friction and friction-less mechanics. since, there has been a lack of clear cut guidelines for clinicians for the optimum method for retraction, this randomized clinical trial was done.

Detailed Description
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Thirty bi-maxillary protrusion female patients were randomly allocated into either intervention groups. In the Friction group, retraction was accomplished using elastomeric power chains extending from crimpable hooks distal to the lateral incisors, on 0.017x0.025-inch Stainless Steel wires, to the mini-screws . While in the friction-less group with retraction done using T- loop springs made of 0.017x0.025-inch titanium molybdenum wires. Retraction force was set to 160g per side in both intervention groups. Activation was done every four weeks. Rate of anterior segment retraction was evaluated via digital models.

Official Title
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Evaluation of the Rate of Anterior Segment Retraction Using Friction Versus Frictionless Mechanics: A Randomized Clinical Trial

Conditions
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Bimaxillary Protrusion

Intervention / Treatment
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* Other: Friction Mechanics
* Other: Frictionless Mechanics


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female Subjects. Age 13-25 y of age. Skeletal Angle Class I malocclusion with Bimaxillary dentoalveolar protrusion in need of four 1st premolar extractions with maximum anchorage. Fully erupted permanent dentition without crowding. Good oral and general health. Exclusion Criteria: Systemic Diseases or syndromes or on anti-inflammatory medication. Extracted or missing permanent teeth. History of previous Orthodontic Treatment. Parafunctional Habits. Badly decayed teeth.

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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Female

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: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Anterior Segment Retraction using Friction mechanics by elastomeric power chains<br>Elastomeric power chains extending from 8mm crimpable hooks, distal to the lateral incisors, on 0.017x0.025 Stainless Steel WIres, to the mini-screws. The power chains delivered 160g of force per side. | Other: Friction Mechanics<br>* anterior segment retraction using elastomeric power chains<br>* Other names: sliding mechanics;|
| Experimental: Anterior Segment Retraction using Frictionless mechanics by T-loops<br>T shaped closing loops were fabricated on 0.017x0.025 Titanium- Molybdenum wires (TMA) were used to deliver 160g of force per side by 4mm distal activations. | Other: Frictionless Mechanics<br>* anterior segment retraction using closing loops<br>* Other names: segmented mechanics;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Anterior Segment Retraction | The rate of anterior segment retraction per month was measured on monthly digital models. | The start of anterior segment retraction up to complete space closure, an average of 6 months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anchorage Loss | Mesial movement of the first primary molar was evaluated on the digital models | The start of anterior segment retraction up to complete space closure, an average of 6 months. | 
| Pain experienced after each activation of the two mechanics | Patients were asked to complete Visual Analogue Scales of the degree of pain after every intervention. The scale values between 0 to 10, with 0 being no pain experienced by the patient and 10 being the highest level of pain experienced. | The start of anterior segment retraction up to complete space closure, an average of 6 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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digital models, T loops, Friction, Frictionless, power chains, anterior segment retraction