Three-dimensionally Printed Hyrax Versus Conventional Hyrax for Maxillary Arch Expansion in Adolescents

February 8, 2026 updated by: Ain Shams University

Three-dimensionally Printed Hyrax Versus Conventional Hyrax for Maxillary Arch Expansion in Adolescents: A Randomized Controlled Trial

This clinical trial aims to compare the skeletal and dental effects of conventional Hyrax expanders and 3D-printed Hyrax expanders in adolescent patients with maxillary transverse deficiency. Using cone-beam computed tomography (CBCT) and digital models, the study evaluates the precision, customization, and treatment outcomes of both appliance types to inform evidence-based orthodontic treatment planning.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Maxillary transverse deficiency is a common orthodontic problem that often requires skeletal expansion using appliances such as the Hyrax expander. While conventional Hyrax expanders have been widely used, advancements in digital dentistry have introduced 3D-printed alternatives that offer potential benefits in precision, customization, and patient comfort. However, there is currently no clinical evidence comparing the skeletal and dental effects of these two designs.

This study addresses this gap by evaluating and comparing the outcomes of conventional and 3D-printed Hyrax expanders in adolescent patients, a critical developmental stage where maxillary expansion becomes more challenging due to progressive maturation and increased resistance of the mid-palatal suture. The study uses cone-beam computed tomography (CBCT) and digital models to assess skeletal and dental changes, providing clinically relevant data to guide orthodontic treatment planning and appliance selection.

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 Contact Backup

Study Locations

  • Egypt
    • Cairo Governorate
      • Cairo, Cairo Governorate, Egypt, 11566
        • Recruiting
        • Faculty of dentistry, Ain Shams univeristy
        • 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

Yes

Description

Inclusion Criteria:

  1. Patients aged between 12 to 17 years.
  2. Skeletal age ranges from CVMS 3 to CVMS 5.
  3. Skeletal maxillary transverse deficiency with/without crossbite.
  4. Cooperative and able to attend follow-up visits.

Exclusion Criteria:

  1. Previous orthodontic treatment.
  2. Craniofacial syndromes, or cleft lip and/or palate.
  3. Patients with vertical growth pattern.
  4. Very bad oral hygiene and active periodontal disease.
  5. Vulnerable groups such as individuals with cognitive impairments or intellectual disabilities and individuals with severe mental health disorders.

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 A: 3D-Printed Hyrax Expander
Adolescent patients diagnosed with transverse maxillary arch constriction will undergo maxillary expansion using a three-dimensionally printed Hyrax expander.
Device: Three dimensionally printed hyrax expander
Group A : A 3D-printed Hyrax expander designed for rapid maxillary expansion in orthodontic treatment. The device is manufactured using additive manufacturing technology for a customized fit.
Active Comparator: Group B: Conventionally Fabricated Hyrax Expander
Adolescent patients diagnosed with transverse maxillary arch constriction will undergo maxillary expansion using using a conventionally fabricated Hyrax expander.
Device: Conventionally Fabricated Hyrax Expander
Group B: A conventionally fabricated Hyrax expander used for rapid maxillary expansion . The device is made using traditional laboratory techniques.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Amount of mid-palatal suture opening.
Time Frame: Three weeks
The amount of suture separation measured in millimeters in the axial plane through CBCT X-ray
Three weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Amount of dental expansion
Time Frame: Three weeks
Dental expansion will be measured as changes in inter-canine width and intermolar width (in millimeters) on digital dental models.
Three weeks
The amount of tipping of maxillary molars and premolars.
Time Frame: Three weeks
Buccolingual tipping of maxillary molars and premolars will be quantified as angular changes measured on CBCT by comparing pre-expansion and post-expansion images.
Three weeks
Change of buccal alveolar bone thickness.
Time Frame: Three weeks
Changes in buccal alveolar bone thickness in millimeters will be measured on pre-expansion and post-expansion CBCT scans.
Three weeks
Pain assessment
Time Frame: Three weeks
Evaluating the pain experienced during the active expansion phase using the Visual Analogue Scale (VAS; 0-100 mm), where 0 mm represents no pain and 100 mm represents the worst imaginable pain; the higher the value in the VAS scale, the more severe the pain.
Three weeks
Oral health-related quality of life.
Time Frame: Three weeks
Oral health-related quality of life was assessed using the Oral Health Impact Profile-14 (OHIP-14). Items are rated on a 5-point Likert scale (0 = never to 4 = very often). Results are presented as mean scores (0-4); higher values indicate worse oral health-related quality of life.
Three weeks
Stability of transverse skeletal width at 6 months post-expansion
Time Frame: Six months
The transverse skeletal dimension after appliance removal after six months post-expansion will be measured in the axial plane on the CBCT X-ray.
Six months

Collaborators and Investigators

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

Sponsor

Ain Shams 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)

August 1, 2025

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

January 1, 2027

Study Registration Dates

First Submitted

January 24, 2026

First Submitted That Met QC Criteria

February 8, 2026

First Posted (Actual)

February 13, 2026

Study Record Updates

Last Update Posted (Actual)

February 13, 2026

Last Update Submitted That Met QC Criteria

February 8, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • FDASU-Rec IR/D072507

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.

Clinical Trials on Transverse Maxillary Deficiency

Clinical Trials on Three dimensionally printed hyrax expander

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Paraguay

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe