A Prospective Randomized Controlled Trial to Evaluate the Effectiveness of the Two Different Appliances in the Treatment of Class II Division 1 Malocclusion

Study Overview
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Brief Summary
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Twin-Block treatment and Dynamax treatment for Class II division 1 malocclusion do not have different effects with regards to treatment duration, the quality of dento-occlusal outcome, skeletal and soft tissue profile, patient discomfort and gingival health.

Detailed Description
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The Dynamax appliance is a relatively new appliance for the treatment of Class II malocclusion and was introduced in 2003. The appliance has the theoretical advantages of incremental mandibular advancement without the need for bite registration, and the ability for the operator to simultaneously provide the functional and fixed appliance phases of treatment. Furthermore, the Dynamax appliance is designed to limit lower both lower incisor proclination and upper incisor retroclination without an increase in lower facial height. There has been limited research into this appliance and only one trial has been carried out. In this study the effects of the Dynamax were compared with the Twin-block, unfortunately, the trial was not carried out to contemporary standards and suffered from severe shortcomings. For example, the non compliance rate was not accounted for in the sample size calculation, the randomisation sequence was not clear, the investigators did not carry out an intention-to-treat analysis, the statistical analysis was simplistic and the study was carried out in a single dental school setting. This raises the question about the efficiency of the Dynamax appliance and whether or not they are effective in a 'real' world setting. The aim of this study is to compare the effectiveness of the Dynamax appliance and the Twin-block appliance for the treatment of Class II Division 1 malocclusion.

Conditions
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Class II Division 1 Malocclusion

Intervention / Treatment
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* Other: Dynamax appliance
* Other: Twin-block appliance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with a Class II malocclusion as defined by British Standards Institute classification. Overjet greater than 6mm Aged 10-14 years Clinical examination indicates a functional appliance is not contraindicated Exclusion Criteria: Orthognathic treatment is required or there is a strong indication it will be required in the future Possession of a craniofacial anomaly Previous orthodontic treatment and/or premolar extraction Hypodontia of more than one teeth in any quadrant excluding third molars Inadequate oral hygiene

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 14 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Functional appliance-Dynamax<br> | Other: Dynamax appliance<br> <br> |
| Other: Functional appliance- twin block<br>Conventional treatment | Other: Twin-block appliance<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of treatment with functional appliance |  | 9 months | 
| Overjet measurement |  | 9 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Harms Breakages Number of treatment visits Total treatment time Quality of occlusal result (PAR Index) Restricted cephalometric (radiograph) analysis Patient perception questionnaire at six months into treatment |  | 9 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Orthodontic treatment of Class II division 1 malocclusion