Effectiveness of Modified Functional Appliance With Expander

A Modified Removable Orthodontic Appliance for Maxillary Expansion and Treatment of Class II Malocclusion: A Randomized Clinical Trial

This clinical trial compares the effectiveness of a myofunctional appliance that uses a clear and modified twin block appliance with an expander made from 2mm biocompatible polyethylene terephthalate modified with Glycol thermoplastic material with a conventional twin block appliance with an expander. The trial will be conducted on adolescent patients with class II division 1.

Study Overview

• Status: Active, not recruiting
• Conditions: Class II Malocclusion
• Intervention / Treatment: Device: Modified twin block appliance with expander; Device: Conventional twin block appliance with expander

Detailed Description

In a multicenter single-blinded randomized clinical trial study with two-arm parallel groups, a computer random generator will develop a simple randomization with an equal allocation ratio (1:1) and without stratification. The investigator will initially assess the patients for eligibility to be included in the study. Those who will meet the inclusion criteria, the parents will be informed about the nature of the study verbally to get the initial approval for participation. Then they will be provided with the patient information sheet and consent form.

According to the sample size calculation, 48 patients will be recruited (24 for each group), and impressions and lateral cephalometric radiography will be taken before treatment and bite registration then the appliance inserted, and the patient will be checked every two weeks for expansion and every four weeks for overjet recording. The treatment will be continuing for 6 months to take final records. The collected data will include cephalometric evaluation, clinical evaluation, scanned upper model evaluation, and finally patient satisfaction from the appliance.

Data will be analyzed using Statistical Package for Social Sciences for Windows, version 26.0 including descriptive statistic (number, mean, and standard deviation), Reliability statistic (interclass correlation coefficient), and Inferential statistics (independent samples t-test).

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Iraq
  • Al-Rusafa, Bab Al-moadham
    • Baghdad, Al-Rusafa, Bab Al-moadham, Iraq, 10011
      • University of Baghdad, Collage of Dentistry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Patients' age at the start of treatment: at growth spurt [in stage 2 (Acceleration) - 3 (Transition) of cervical vertebral maturation].
2. Skeletal and dental relationships: skeletal class II with normal maxilla and retrognathic mandible. Moderate to severe dental class II division 1 malocclusion with overjet ≥ 8 mm.
3. Horizontal/normal growth pattern.
4. Convex profile with decreased or normal lower facial height (clinically and radiographically).
5. Well-aligned/mild crowding of maxillary and mandibular dental arches.
6. Good oral health free from caries and periodontal problems at the start of treatment.

Exclusion Criteria:

1. Patients with vertical growth pattern or backward mandibular rotation tendency.
2. Patients with open bite
3. Patients with obvious facial asymmetry.
4. Patients with orofacial clefting.
5. Patients with bad oral habits.
6. Active periodontal disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Modified twin block appliance with expander group; For 24 patients with class II division malocclusion in their growing stages, using a 2 mm biocompatible and rigid PET-G thermoforming material to create two clear appliances for each patient. The material will be adapted separately on maxillary and mandibular casts using a pressure molding vacuum machine. Then, the appliances will be trimmed and finished and transferred to the articulator with the aid of a pre-existing working wax bite. The ramps will be made of cold cure acrylic on the thermoplastic sheets. Next, the expansion screw will be placed in the midline of the maxillary cast, and the maxillary appliance will be split midpalatally to fit the patient's individual needs.	Device: Modified twin block appliance with expander; These appliances are myofunctional appliance used for treating class II division growing adolescents.; Device: Conventional twin block appliance with expander; These appliances are myofunctional appliances used for treating class II division growing adolescents.
Experimental: Conventional twin block appliance with expander group; For 24 patients in a growing stage with class II division 1 malocclusion, these appliances will consist of removable maxillary and mandibular appliances. These will have a labial bow, Adam's clasps on the first molars, ball end clasps with incisal capping and expansion screw. The inclined bite blocks (ramps) will act as a guide to move the mandible forward.	Device: Modified twin block appliance with expander; These appliances are myofunctional appliance used for treating class II division growing adolescents.; Device: Conventional twin block appliance with expander; These appliances are myofunctional appliances used for treating class II division growing adolescents.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anteroposterior skeletal changes	Skeletal changes using cephalometric radiographs including different angular measurements to estimate the changes between dental bases before and after treatment.	T0 (before treatment), T1 (at end of the study) around 6-9 months
Vertical skeletal changes	Skeletal changes using cephalometric radiographs including different linear measurements to estimate the changes between dental bases before and after treatment.	T0 (before treatment), T1 (at end of the study) around 6-9 months.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Soft tissue change	Measurements using cephalometric radiographs including different angular measurements to estimate the soft tissue changes before and after treatment.	T0 (before treatment), T1 (at end of the study) around 6-9 months
Dentoalveolar changes	Measurements using cephalometric radiographs include different angular measurements to estimate the changes between teeth before and after treatment.	T0 (before treatment), T1 (at end of the study) around 6-9 months
Study model evaluation	The scanned upper study model will be used to calculate the amount of expansion before and at the end of the study.	T0 (before treatment), T1 (at end of the study) around 6-9 months.
Patient satisfaction from the appliance	Patient satisfaction with both appliances will be estimated using a questionnaire at the middle of treatment.	around 4 months.

Collaborators and Investigators

• Sponsor: University of Baghdad
• Investigators: Study Chair: Yassir A Yassir, Ph.D. (UK), Baghdad University, Collage of Dentistry

Study record dates

Study Major Dates

• Study Start (Actual): May 9, 2023
• Primary Completion (Estimated): May 9, 2024
• Study Completion (Estimated): June 9, 2024

Study Registration Dates

• First Submitted: October 21, 2023
• First Submitted That Met QC Criteria: October 31, 2023
• First Posted (Actual): November 3, 2023

Study Record Updates

• Last Update Posted (Actual): November 7, 2023
• Last Update Submitted That Met QC Criteria: November 3, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: adolescent; clinical trial; twin block; thermoplastic material; clear expander,
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Malocclusion; Malocclusion, Angle Class II; Overbite
• Other Study ID Numbers: 664422

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No