Clear Orthodontic Expander Versus Hyrax

NCT07362160 | Recruiting DMC

• 2 other identifiers: 11584251158
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This study will be conducted to evaluate the effectiveness of a clear expander fabricated from 2-mm biocompatible polyethylene terephthalate glycol (PETG) thermoforming material integrated with an expansion screw in achieving dental and skeletal expansion in adolescent patients, compared with the conventional Hyrax expander.

Conditions

Narrow Maxilla; Malocclusion

Keywords

clear expander; hyrax; clinical trial; adolescent; thermoplastic material

Outcome Measures

Primary Outcomes (1)

• CBCT evaluation

  Skeletal and dentoalveolar measurements will be assessed using cone-beam computed tomography (CBCT). Skeletal measurements will include nasal width, midpalatal suture gap, and palatal height, measured in millimeters (mm). Dentoalveolar measurements will include vertical dental heights and maxillary width measured in millimeters (mm), as well as dental inclination measured in degrees (°). All measurements will be obtained from CBCT images using dedicated three-dimensional imaging analysis software.

  pre-treatment (T0) and immediately post-treatment (T1) around one to two months

Secondary Outcomes (5)

• Intraoral scan of the maxillary arch evaluation

  pre-treatment (T0) and post-treatment (T1) around one to two months

• Clinical evaluation

  pre-treatment (T0) and immediately post-treatment (T1) around one to two months

• Cephalometric analysis

  pre-treatment (T0) and immediately post-treatment (T1) around one to two months

• Microbial evaluation

  after one month.

• Patient satisfaction with the appliance

  around one to two months

Study Arms (2)

New clear expander

EXPERIMENTAL

After obtaining the 3D-printed maxillary dental cast, a 2 mm PETG (rigid) thermoforming material (Leone® S.p.A., Florence, Italy) will be adapted separately to the maxillary cast using a pressure molding vacuum machine. The clear appliance will then be trimmed and finished. Depending on the degree of maxillary constriction, a Leone® Standard or universal expansion screw (Leone® S.p.A.,Florence, Italy) measuring 6-9 mm will be incorporated into the appliance and positioned in the midline of the maxillary cast after splitting the appliance midpalatally embedded in acrylic composed from Methyl methacrylate monomer and Methyl methacrylate polymer Orthocryl® liquid (monomer), and Orthocryl® EQ-powder (polymer) (Dentaurum GmbH \& Co. KG, Ispringen, Germany)

Device: New clear expander

Hyrax expander

EXPERIMENTAL

After obtaining the 3D-printed maxillary dental cast, patients will be treated with a Hyrax expander using a rapid expander from Leone® S.p.A., Florence, Italy, cemented in the upper first premolars and first molars. If the first premolars had not yet erupted, the Hyrax expander will be cemented in the upper first permanent molars only.

Device: Hyrax expander

Interventions

New clear expander DEVICE

All patients with a clear expander will be instructed to wear the appliance 24 hours a day, except during eating and cleaning. The expander will be activated twice daily (0.2 mm per turn). Patients will be provided with an instruction brochure and advised to use a reminder to ensure compliance. The expansion will continue until the desired amount of the maxillary arch expansion occurs when the maxillary first molars' palatal cusps occlude the lingual side of the mandibular first molar buccal cusps to overcome the expected relapse due to the elasticity of the palatal soft tissue.

New clear expander

Hyrax expander DEVICE

The activation protocol for the Hyrax expander will be the same in all patients, twice daily (0.2 mm per turn). The expansion will continue until the desired amount of the maxillary arch expansion occurs when the maxillary first molars' palatal cusps occlude the lingual side of the mandibular first molar buccal cusps to overcome the expected relapse due to the elasticity of the palatal soft tissue.

Hyrax expander

Eligibility Criteria

• Age: 10 Years - 14 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• Patients' age at the start of treatment will range from 10-14 years.
• Unstable unilateral or bilateral posterior crossbite due to maxillary constriction.
• The first molars are fully erupted.
• Good oral health free from caries and periodontal problems at the start of treatment.
• Good general health.

You may not qualify if:

• Patients with obvious facial asymmetry.
• Patients with orofacial cleft.
• Patients with previous orthodontic treatment.
• Patients with bad oral habits.
• Patients with active periodontal disease.

Sponsors & Collaborators

• University of Baghdad: lead

Study Sites (1)

University of Baghdad/Collage of Dentistry

Baghdad, Al-Rusafa, Bab Al-moadham, Iraq

RECRUITING

MeSH Terms

Conditions

Malocclusion

Condition Hierarchy (Ancestors)

Tooth Diseases; Stomatognathic Diseases

Study Officials

• Yassir A Yassir, Ph.D. (UK)

  University of Baghdad

  STUDY CHAIR

Central Study Contacts

Noor FK Al-Khawaja, BDS, MSc

CONTACT

+9647712222834; noor.alkhawaja@codental.uobaghdad.edu.iq

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: As the study will be conducted in different clinics, all data collection and measurement will be completed with the investigator being masked to the allocation groups, though blinding of the operator will not be possible due to the appliance design/shape difference, and for the cleaning methods, blinding will be applied for the bacteriological specialist, and for the outcome assessor.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: postgraduate/PhD student

Model Details: hyrax expander clear orthodontic expander

Study Record Dates

• First Submitted: January 12, 2026
• First Posted: January 23, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): February 1, 2027
• Last Updated: April 22, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

IR (1)