The Use of an Esthetic Twin Block for Patients With Mandibular Retrusion

Study Overview
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Brief Summary
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This experimental study will evaluate the effect of an esthetic Twin-block appliance on the correction of class II malocclusion compared with the traditional Twin-block appliance. The study sample will consist of 50 patients with class II malocclusion. The sample will be allocated randomly into two groups: the control group and the experimental group. The traditional Twin-block appliance will be applied for the control group patients, while the esthetic Twin-block appliance will be applied for the experimental group patients. The dentoskeletal, soft tissue changes and esthetic and functional efficacy occurring after functional treatment will be assessed using cephalometric radiographs and profile photographs, pre and post-treatment, and a questionnaire. Changes for each group will be evaluated individually, and the two groups will be compared.

Detailed Description
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Class II malocclusion is one of the most frequent orthodontic problems, and most class II malocclusion cases are the result of mandibular deficiency. Twin block (TB) is one of the most popular functional appliances to treat this condition. Despite excellent treatment results with TB, its acceptance and compliance may be hampered by its wiry structure and appearance. Furthermore, it has a side effect of causing the proclination of lower incisors, which reduces skeletal change. Various modifications were proposed to reduce lower incisors proclination but had no significant effect. Patient cooperation is one of the most important factors for successful functional appliance treatment, and it depends upon comfort and esthetic acceptability, which ensures good patient compliance. so, in order to enhance the esthetic appearance and overcome the disadvantages of a conventional Twin-Block (CTB), a novel esthetic Twin-Block (ETB) was fabricated from a specific material using a pressure molding device and acrylic bite blocks. There is only one study that evaluated this appliance which is a pilot study that compared the treatment effects of the (ETB) and (CTB) in the treatment of Class II malocclusions. However, this study has a lot of limitations, making it difficult to evaluate this appliance's efficiency accurately. The aim of this study is to study the dento-skeletal, soft tissue changes, and esthetic and functional efficacy that result from treatment by this appliance (ETB) and to compare them to the changes in the matched group will be treated with (CTB), by studying the cephalometric radiographs, profile photographs, and a questionnaire.

Official Title
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Dentoskeletal Changes Resulting From Treatment of Skeletal Class II With an Esthetic Twin Block Appliance.

Conditions
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Class II Malocclusion

Intervention / Treatment
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* Device: CTB
* Device: ETB


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Angle class II malocclusion because of mandibular retrognathia O.J > 5 , SNB < 78 Patient during growth spurt Normal or horizontal growth pattern Björk > 402 Exclusion Criteria: TMJ disorders Poor oral hygiene Previous orthodontic treatment. Patients with syndromes, clefts, or craniofacial abnormalities. Reason of contraindication of functional treatment

Ages Eligible for Study
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Minimum Age: 11 Years
Maximum Age: 14 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: Conventional Twin-block appliance<br>The patients in this control group will be treated using the conventional Twin-block appliance (CTB). | Device: CTB<br>* conventional Twin-block (CTB) will be comprised of maxillary and mandibular removable appliances having the labial bows, adam's clasps, and with no incisal capping.<br>|
| Experimental: Esthetic Twin-block appliance<br>the patients in this experimental group will be treated using the esthetic Twin-block appliance (ETB). | Device: ETB<br>* will be comprised of maxillary and mandibular removable 1.5-mm biocryl sheet will be adapted separately on maxillary and mandibular casts with help of vacuum machine, and Acrylic bite blocks with the inclined plane will be fabricated on biocryl sheets sim<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dentoskeletal mandible changes as measured by tomographic | changes of the mandible before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs | Assessment will be done before treatment (T0) and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1). | 
| Lower incisor angle changes | Lower incisor angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs. | Changes will be evaluated before treatment and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1) | 
| ANB angle changes | ANB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs. | Changes will be evaluated before treatment and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dentoskeletal maxilla changes as measured by tomographic superimposition of the cranial base | changes of the maxilla before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs. | Assessment will be done before treatment (T0) and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1) | 
| SNA angle changes | SNA angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs. | Assessment will be done before treatment (T0) and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1) | 
| SNB angle changes | SNB angle changes before and after treatment will be assessed and compared with those of the control group using lateral cephalometric radiographs. | Assessment will be done before treatment (T0) and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1). | 
| Soft tissue changes | Soft tissue changes before and after treatment will be assessed and compared with those of the control group (Facial convexity angle, Nasolabial angle, Z-Merrifield angle, …etc) using profile photography. | Assessment will be done before treatment (T0) and after obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months (T1) | 
| The duration of functional treatment | The duration of the functional treatment will be measured and compared between groups. | After obtaining 0-1.5 mm overjet and the occlusion settled into a class I or superclass I molar relationship which will be approximately obtained after 8 months | 
| Levels of pain | The level of pain will be assessed and compared with those of the control group using a questionnaire with a Visual Analog Scale (VAS). The VAS is a 10-cm horizontal line with two focal points at its beginning and end (0: there is no pain - 10: the worst pain). | A questionnaire will be given to the patients five times during treatment; after 1 week, after 1 week, after 6 weeks, after 3 months and at the end of the application of the appliance. | 
| Levels of discomfort | The level of discomfort will be assessed and compared with those of the control group using a questionnaire with a Visual Analog Scale (VAS). The VAS is a 10-cm horizontal line with two focal points at its beginning and end (0: there is no discomfort - 10: the worst discomfort). | A questionnaire will be given to the patients four times during treatment; after 1day, after 1 week, after 6 weeks, after 3 months and at the end of the application of the appliance. | 
| Levels of acceptance | The level of acceptance will be assessed and compared with those of the control group using a questionnaire with a Visual Analog Scale (VAS). The VAS is a 10-cm horizontal line with two focal points at its beginning and end (0: no acceptance - 10: the best acceptance). | A questionnaire will be given to the patients four times during treatment; after 1day, after 1 week, after 6 weeks, after 3 months and at the end of the application of the appliance. | 
| Number of broken appliances | The number of broken will be counted and compared with those of the control group . | During the treatment time which will take approximately 8 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Class II, Twin Block, Functional Therapy