Three-Dimensional Evaluation of Pharyngeal Airway and Facial Dimension Changes in Skeletal Class II Patients Treated With Twin Block Versus Myobrace Appliances

NCT06976749 | Enrolling By Invitation DMC

• 1 other identifier: 1033425
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

This study is intended primarily to compare the effects of two Class II correction appliances, namely Twin block and Myobrace appliances, on pharyngeal airway dimensions during the treatment of class II division 1 adolescent patients, also evaluates three dimensional (3D) changes of pharyngeal airway including: minimum cross-sectional area and volume using Cone Beam Computed Tomography (CBCT), skeletal, dentoalveolar, and soft tissue changes using cephalometric analysis, and three dimensional (3D) soft tissue changes using facial scans. The hypothesis being a consideration of no significant difference in the changes of pharyngeal airway and facial dimensions in skeletal class II patients before and after treatment with Twin block and Myobrace.

Conditions

Class II Division 1 Adolescent Patients

Keywords

class II division 1 malocclusion; mandibular retrognathism; retrognathic mandible; Pharyngeal Airway; Twin block; Myobrace; Three-Dimensional Evaluation; facial scan

Outcome Measures

Primary Outcomes (1)

• minimum cross-sectional area of the pharyngeal airway in (mm^2) using Cone Beam Computed Tomography (CBCT)

  3D measurements of pharyngeal airway minimum cross-sectional (mm\^2) will be performed for all participants of both groups at two stages before treatment and at the end of the study using CBCT

  From enrollment to the end of treatment at 6 months

Secondary Outcomes (6)

• three dimensional changes in the volume of the pharyngeal airway using CBCT

  From enrollment to the end of treatment at 6 months

• Skeletal changes using cephalometric analysis

  From enrollment to the end of treatment at 6 months

• Soft tissue changes using cephalometric analysis

  From enrollment to the end of treatment at 6 months

• Dentoalveolar changes using cephalometric analysis

  From enrollment to the end of treatment at 6 months

• Dental changes using study models

  From enrollment to the end of treatment at 6 months

Study Arms (2)

Twin block appliance

EXPERIMENTAL

It consists of maxillary and mandibular appliances that fit tightly against the teeth, alveolus, and adjacent supporting structures. Adams' clasps will be used bilaterally to anchor them to the first permanent molars and lower first premolars. A short passive labial bow will be added to the upper arch and ball end clasps to the interproximal areas of the lower arch for retention. The appliance will be fabricated after a symmetric protrusive bite registration using pink modeling wax sheets, in which the patients will rehearse many times before registration. The inclined bite blocks (ramps) will be at 70 which acts as a guiding mechanism for forward displacement of the mandible. The working bite will be taken with the incisors in an edge-to-edge relationship if possible and 2 to 3 mm bite opening between the central incisors. All the subjects will be instructed to wear the appliance 24 hours/day except for brushing. If further advancement

Device: Twin block

Myobrace appliance

EXPERIMENTAL

The appropriate size of Myobrace is chosen by using a special ruler to measure the distance between the distal portion of the lateral upper right incisor and the left, regardless of any crowding or diastema. The measure is based on the mesial-distal dimensions of the upper incisors, and not on their position. This distance is used to determine the correct size using a special table. Once chosen and inserted in patient's mouth, upper canines, even if not yet erupted, must be in their slots, so that the dental mildines coincided with the appliance's midline. In the first week, the patients will be instructed to gradually increase the wearing time of the appliance during the daytime. By the start of the second week, the patients will be instructed to wear the appliance achieving at least 8 hours during sleeping. By the end of the first 4 weeks, the patients will wear the appliances minimum of 1- 2 hours during the day plus the overnig

Device: myobrace appliance

Interventions

myobrace appliance DEVICE

functional appliance

Myobrace appliance

Twin block DEVICE

functional appliance

Twin block appliance

Eligibility Criteria

• Age: 10 Years - 14 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Age: 10-14 years, at growth spurt phase as determined by the cervical vertebrae maturation stage (C3- C4 ) assessed by lateral cephalograms.
• Skeletal relationship: skeletal class II (ANB angle \> 4°) with normal maxilla (SNA angle 78°- 84°), and retrognathic mandible (SNB angle \< 77 °).
• Dental relationship: Moderate to severe dental class II division 1 malocclusion with overjet 6 -10 mm.
• Convex facial profile.
• Well aligned/mild crowding (\< 4 mm) of dental arches.
• Good to fair oral hygiene status as based on a simplified oral hygiene index (OHI-S).
• Normal or decreased lower facial height (SN-MP angle ≤ 32).

You may not qualify if:

• Previous orthodontic/orthopedic treatment.
• Patients with dental open bite
• Patients with obvious facial asymmetry.
• Patients with orofacial cleft.
• Previous extractions.
• Presence of mandibular shifts.

Sponsors & Collaborators

• University of Baghdad: lead

Study Sites (1)

University of Baghdad, College of Dentistry

Baghdad, Iraq

Location

Related Publications (1)

• Kim SS, Kim YI, Park SB, Kim SH. Three-dimensional evaluation of the pharyngeal airway space in patients with anterior open bite. Korean J Orthod. 2023 Nov 25;53(6):358-364. doi: 10.4041/kjod22.187. Epub 2023 Jan 31.

  PMID: 36718119 BACKGROUND

Related Links

• Related Info

MeSH Terms

Conditions

Malocclusion, Angle Class II

Condition Hierarchy (Ancestors)

Malocclusion; Tooth Diseases; Stomatognathic Diseases

Study Officials

• Lubna M Hussein, B.D.S., M.Sc. (Orthodontics)

  University of Baghdad

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: statistician
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: two-parallel arms with equal allocation ratio of 1:1

Study Record Dates

• First Submitted: March 19, 2025
• First Posted: May 16, 2025
• Study Start: May 20, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: May 16, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: starting 6 months after publication.

Locations

IR (1)