Cephalometric Evaluation of a Clear Mandibular Advancement Appliance Based on the Twin-block Design

Study Overview
=================
Brief Summary
-----------------
This study evaluates the cephalometric effects of a clear mandibular advancement appliance for the treatment of skeletal class II growing patients suffering from mandibular deficiency.

Detailed Description
-----------------
A Clear mandibular advancement appliance is constructed comprised of a clear dental splint of 1.5 mm thickness adapted on the patient's teeth. This is followed by the construction of acrylic bite ramps bonded over the splints. The bite ramps are constructed as such when the patient bites into occlusion, he/she has to advance the mandible to bring the two parts of the appliance together. Lateral cephalometric radiographs were obtained pre and post-treatment to evaluate the effects on the patient's maxilla, mandible and dentition.

Official Title
-----------------
Cephalometric Evaluation of a Clear Mandibular Advancement Appliance Based on the Twin-block Design

Conditions
-----------------
Skeletal Malocclusion

Intervention / Treatment
-----------------
* Device: Clear Mandibular Advancement Appliance


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Gender: Female subjects. Chronological age: All recruited subjects were between the ages of 8-12 years. Anteroposterior skeletal relationship: Subjects with skeletal Class II malocclusion with normal maxilla and retrognathic mandible were selected. This was confirmed using lateral cephalometric radiographic analysis with the following parameters: decreased effective mandibular length (Co-Gn) according to McNamara composite , SNB<78, SNA=82+2. Dental characteristics: Angle Class II molar relationship ranging from edge to edge to full unit Class II. Overjet ranging between 5-10 mm. Absence of posterior crossbite and/or tendency for posterior crossbite. Skeletal maturation stage: The growth stage for all subjects was selected to be before or at the prepubertal growth spurt. This was confirmed by cervical vertebral maturation analysis from the lateral cephalometric radiograph. The cervical vertebrae maturation stage required was Cervical Vertebrae Maturation stage 2-3 according to the cervical vertebrae maturation index by Baccetti et al. allowing sufficient time before the end of the growth spurt. No previous history of orthodontic treatment. Absence of systemic diseases affecting growth or craniofacial development. - Exclusion Criteria: -

Ages Eligible for Study
-----------------
Minimum Age: 8 Years
Maximum Age: 12 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment arm<br>Subjects receiving the clear mandibular advancement appliance | Device: Clear Mandibular Advancement Appliance<br>* Clear Mandibular Advancement Appliance for treatment of skeletal class II patients with retrognathic mandible<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effective Mandibular Length | Condylion-Gnathion | 12 months | 
| Mandible to cranial base | Sella-Nasion-B point | 12 months | 
| Effective maxillary length | Condylion-A point | 12 months | 
| Maxilla to cranial base | Sella-Nasion-A point | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lower incisor inclination | Lower incisor to mandibular plane | 12 months | 
| Lower incisor AP position | Lower incisor Anteroposterior position | 12 months | 
| Upper incisor inclination | Upper incisor to palatal plane | 12 months | 
| Upper incisor AP position | Upper incisor Anteroposterior position | 12 months | 
| Profile convexity | N'Sn/Sn-Pog' | 12 months | 
| Lip protrusion | Ls-E plane | 12 months | 
| Chin position | Soft tissue Pogonion position | 12 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Functional appliance, skeletal class II, mandibular deficiency, twin-block, Growing patients, Clear appliance, Aligner