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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03824574
Recruitment Status : Completed
First Posted : January 31, 2019
Last Update Posted : January 31, 2019
Information provided by (Responsible Party):
Ahmed Mostafa Zaky, Ain Shams University

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.

Condition or disease Intervention/treatment Phase
Skeletal Malocclusion Device: Clear Mandibular Advancement Appliance Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Cephalometric Evaluation of a Clear Mandibular Advancement Appliance Based on the Twin-block Design
Actual Study Start Date : September 20, 2016
Actual Primary Completion Date : December 15, 2017
Actual Study Completion Date : March 4, 2018

Arm Intervention/treatment
Experimental: Treatment arm
Subjects receiving the clear mandibular advancement appliance
Device: Clear Mandibular Advancement Appliance
Clear Mandibular Advancement Appliance for treatment of skeletal class II patients with retrognathic mandible

Primary Outcome Measures :
  1. Effective Mandibular Length [ Time Frame: 12 months ]

  2. Mandible to cranial base [ Time Frame: 12 months ]
    Sella-Nasion-B point

  3. Effective maxillary length [ Time Frame: 12 months ]
    Condylion-A point

  4. Maxilla to cranial base [ Time Frame: 12 months ]
    Sella-Nasion-A point

Secondary Outcome Measures :
  1. Lower incisor inclination [ Time Frame: 12 months ]
    Lower incisor to mandibular plane

  2. Lower incisor AP position [ Time Frame: 12 months ]
    Lower incisor Anteroposterior position

  3. Upper incisor inclination [ Time Frame: 12 months ]
    Upper incisor to palatal plane

  4. Upper incisor AP position [ Time Frame: 12 months ]
    Upper incisor Anteroposterior position

  5. Profile convexity [ Time Frame: 12 months ]

  6. Lip protrusion [ Time Frame: 12 months ]
    Ls-E plane

  7. Chin position [ Time Frame: 12 months ]
    Soft tissue Pogonion position

Information from the National Library of Medicine

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Ages Eligible for Study:   8 Years to 12 Years   (Child)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Gender: Female subjects.
  2. Chronological age: All recruited subjects were between the ages of 8-12 years.
  3. 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.
  4. 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.
  5. 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.
  6. No previous history of orthodontic treatment.
  7. Absence of systemic diseases affecting growth or craniofacial development. -

Exclusion Criteria:



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Responsible Party: Ahmed Mostafa Zaky, Lecturer of Orthodontics, Ain Shams University Identifier: NCT03824574    
Other Study ID Numbers: AinShamsUOrthodontics
First Posted: January 31, 2019    Key Record Dates
Last Update Posted: January 31, 2019
Last Verified: January 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Ahmed Mostafa Zaky, Ain Shams University:
Functional appliance
skeletal class II
mandibular deficiency
Growing patients
Clear appliance
Additional relevant MeSH terms:
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Tooth Diseases
Stomatognathic Diseases