The Effect of Functional Treatment of Patients With Backward Positioned Chins on the Jaw Joint and Movements

Study Overview
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Brief Summary
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Patients with class II malocclusion and retrognathic mandibles will be treated using functional appliances and asses the remodeling that is expected to occur in the temporomandibular joint (TMJ) using cone-beam computed tomography (CBCT) images and we will register mandibular movements using electronic axiograph ( a specific apparatus used to record jaw movements in three dimensions). There are three groups : Activator Group Twin block Group Control Group with no treatment. Patients will be allocated to the three groups randomly. Data will be collected using three different approaches: CBCT images before treatment and 12 months after treatment Axiograph registrations before treatment and 12 months after treatment

Detailed Description
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The main purposes of this project are: to evaluate the remodeling effects that would take place in the bone structures of the temporomandibular joint (TMJ) during functional treatment. to evaluate the possible change that may occur in mandibular movements following functional treatment. to evaluate the possible change in the spatial relationship between centric occlusion (CO) and centric relation (CR) following functional treatment

Official Title
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The Effect of Functional Treatment Using the Activator Versus the Twin Block on the Temporomandibular Joint and the Mandibular Movements in Skeletal Class II Patients: A Randomized Controlled Clinical Trial

Conditions
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TMJ, Malocclusion, Angle Class II, Retrognathism

Intervention / Treatment
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* Device: Activator
* Device: Twin Block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Class II malocclusion Skeletal class II with retruded mandibles. Old between 10-13 years Healthy TMJ Horizontal or normal growth pattern Exclusion Criteria: Patients who have been treated previously Patients with syndromes or congenital deformities Signs or symptoms of temporomandibular disorders.

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 13 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: Activator<br>Patients will be treated using the Activator appliance for one and a half year | Device: Activator<br>* This appliance is constructed in one piece to guide the position of the mandible on closure<br>* Other names: Andresen Appliance;|
| Experimental: Twin Block<br>Patients will be treated using the Twin Block appliance for 18 months on average | Device: Twin Block<br>* This appliance is constructed in two pieces to guide the position of the mandible on closure<br>* Other names: Clark's appliance;|
| No Intervention: Control<br>Patients will be monitored until the last assessment times in the other groups. This group will serve as a control group | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Glenoid Fossa Height | Glenoid fossa height: the vertical space between the roof and lowest edge of the fossa. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Glenoid Fossa Width | Glenoid fossa width: the horizontal space between the anterior and posterior wall of the fossa. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Articular Eminence Inclination | Articular Eminence inclination: the angle between a horizontal plane and the posterior slope of the articular eminence. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Condylar Height | Condylar Height: the vertical height of the head of the condyle. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Condylar Width | Condylar Width: the horizontal width of the head of the condyle. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Condylar Length | Condylar Length: the mesio-distal length of the head of the condyle. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Condylar Circumference | Condyle circumference: the outer circumference of the head of the condyle. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in the Anterior Joint Space | Anterior Joint Space: the space between the anterior edge of condyle and the posterior slope of the articular eminence. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in the Superior Joint Space | Superior Joint Space: the space between the superior edge of the condyle and the roof of the fossa. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in the Posterior Joint Space | Posterior joint space: the space between the posterior edge of the condyle and the posterior board of the fossa. This measurement will be done on the 3D software (3D OnDemand) using CBCT images | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in Border Mandibular Movements | Border mandibular movements will be measured on the axiograph apparatus (called Arcosdigma(R)). | T1: at one day before the commencement of treatment; T2: after 12 months of treatment | 
| Change in the Discrepancy between CO and CR | CO-CR discrepancy: we will measure distance between centric relation and centric occlusion in three dimensions (sagittal, coronal and axial ). These measurements will be done by an electronic axiograph (Arcosdigma(R)) | T1: at one day before the commencement of treatment; T2: after 12 months of treatment |