Posterior Resin Bite Turbos Effect on Maxillary Expansion Using a HYRAX Expander in Early Adolescents (HYRAX_ RME_SME)

August 13, 2026 updated by: Mansoura University

Effect of Posterior Disarticulatory Resin Bite Turbos on the Rate of Maxillary Expansion Using HYRAX Expander in Early Adolescent Patients: Randomized Controlled Clinical Trial

This randomized controlled clinical trial aims to evaluate the effect of posterior disarticulatory resin bite turbos on the rate of maxillary expansion using a HYRAX expander in early adolescent patients. Participants will be randomly assigned to receive either maxillary expansion with posterior resin bite turbos or conventional expansion without bite turbos. The study will assess and compare the rate and effectiveness of maxillary expansion between the two groups during the treatment period. Clinical measurements will be recorded to evaluate skeletal and dental changes associated with the intervention.

Study Overview

Detailed Description

This study is conducted as part of a Master's thesis in Orthodontics and aims to investigate the influence of posterior disarticulatory resin bite turbos on the rate of maxillary expansion achieved using a HYRAX expander in early adolescent patients.

The study evaluates whether modifying occlusal contacts can affect skeletal and dental responses during rapid maxillary expansion.

Participants will be monitored clinically throughout the expansion phase.

Participants will be assigned in two groups:

group 1: with posterior bite turbos group 2: without posterior bite turbos

Digital intraoral scans will be taken on a weekly basis to assess changes in maxillary dimensions and to accurately measure the rate and pattern of expansion over time.

These serial digital records provide high-resolution, non-invasive documentation of treatment progress.

CBCT will be taken before the expansion and after retention phase for skeletal and dental measurement .

Study Type

Interventional

Enrollment (Estimated)

22

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

      • Al Mansurah, Egypt
        • Recruiting
        • Orthodontic Department - Faculty of Dentistry Mansoura University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients aged 10-14 years.
  2. Bilateral posterior cross bite.
  3. Functional lateral cross bite.
  4. Good general and oral health.
  5. Normal to decreased vertical height )average FMA 29.7 °± 4.2 °).23

Exclusion Criteria:

  1. Patients with cleft lip and palate.
  2. Severe facial asymmetry.
  3. Anterior open bite.
  4. Systemic conditions affecting tooth movement (e.g., diabetes, bone disorders).
  5. Previous orthodontic treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: group 1: HYRAX with posterior bite turbos
Participants in this arm receive a HYRAX rapid maxillary expansion appliance combined with posterior disarticulatory resin bite turbos. The bite turbos are placed on posterior teeth to achieve occlusal disclusion, aiming to minimize occlusal interference during expansion and potentially enhance skeletal response. The HYRAX expander is activated according to a standardized protocol throughout the treatment period, with regular follow-up using clinical assessment and weekly intraoral scans.

Description:

Arm 1:

Participants in this group receive a HYRAX rapid maxillary expansion appliance combined with posterior disarticulatory resin bite turbos. The bite turbos are placed on the posterior teeth to disclude the occlusion, aiming to reduce occlusal interference and potentially enhance skeletal response during maxillary expansion. The HYRAX appliance is activated according to a standardized expansion protocol.

Active Comparator: Group 2 : Expansion without posterior bite turbos
Participants in this arm receive a HYRAX rapid maxillary expansion appliance without the use of posterior disarticulatory resin bite turbos. The appliance is activated according to a standardized expansion protocol similar to the experimental group. Patients are followed throughout the treatment period with regular clinical assessments and weekly intraoral scans to monitor changes in maxillary dimensions.
Participants in this group receive a HYRAX rapid maxillary expansion appliance alone without the use of posterior bite turbos. The appliance is activated following the same standardized expansion protocol as the intervention group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The effect of occlusal disarticulation on the rate of maxillary expansion by linear measurements made on digital models
Time Frame: Baseline and weekly during the active phase of expansion and after 3 months of retention

Dental landmarks and measurements on models :

d3 :Canine tip. d4: Central fissure of first premolar. d6 :Central fissure of first permanent molar. d_3( inter canine width): Distance between left and right d3. d_4 (inter first premolar width) : Distance between left and right d4.

d_6(inter first molar width): Distance between left and right d6.

Baseline and weekly during the active phase of expansion and after 3 months of retention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
-The effect of the posterior disarticulation on alveolar bone changes by CBCT .
Time Frame: baseline and after three months of retention after complete active expansion
Skeletal transverse, vertical, nasal width changes and axial inclination of posterior teeth will be evaluated .
baseline and after three months of retention after complete active expansion
pain felt by the patient after activating the expansion screw
Time Frame: first two weeks in active phase of expansion
ain will be assessed using the Visual Analogue Scale (VAS), a 100 mm line with "no pain" at the left end and "the worst unbearable pain" at the right, which corresponds to a pain score between 0 and 10. All participants will be asked to place a vertical mark indicating the level of pain on the VAS 4 h after each activation for the first two weeks in diary sheet containing the actual size of a 100mm of VAS. 25
first two weeks in active phase of expansion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Donia Alashker, Faculty of Dentistry Mansoura University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 15, 2026

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

July 28, 2026

First Submitted That Met QC Criteria

July 28, 2026

First Posted (Actual)

July 31, 2026

Study Record Updates

Last Update Posted (Actual)

August 17, 2026

Last Update Submitted That Met QC Criteria

August 13, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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