MalocclusionCOE-HyarxNCT07362160
Clear Orthodontic Expander Versus Hyrax
A study testing New clear expander and Hyrax expander in people with Malocclusion and Narrow Maxilla, run by University of Baghdad at 1 site in Iraq.
Trial 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… Read more about this study
- Who is it for?
- Ages 10 to 14 yearsHealthy volunteers can take part
- Conditions the study is for
- Malocclusion, Narrow Maxilla
- What is being tested?
- New clear expander and Hyrax expander
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteIraq
- Study dates
- 1 Feb 2026to 1 Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 14 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- 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.
Who cannot join
- Patients with obvious facial asymmetry.
- Patients with orofacial cleft.
- Patients with previous orthodontic treatment.
- Patients with bad oral habits.
- Patients with active periodontal disease.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Iraq1 site, 1 recruiting
- Recruiting
University of Baghdad/Collage of Dentistry
Baghdad, Al-Rusafa, Bab Al-moadham
Noor FK Al-Khawaja, BDS, MSc, +9647712222834, noor.alkhawaja@codental.uobaghdad.edu.iq
About this study
Official title: Evaluating the Clinical Performance of a Novel Clear Orthodontic Expander Versus Hyrax: A Randomized Clinical Trial
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.
Read the detailed description
This will be a multicenter randomize clinical trial with two-arm parallel groups, and will be conducted at the Department of Orthodontics, College of Dentistry, University of Baghdad, as well as different specialized dental centers affiliated with the Iraqi Ministry of Health, and some private clinics.
The sample size will be calculated based on previous studies with similar aim to measure the skeletal expansion. A minimum sample size of 17 patients was required, and in order to account for a 15% dropout, a total of 20 patients will be recruited for each group (new clear expander and hyrax expander). The amount of 2.5 mm or greater of maxillary sutural opening will be considered clinically effective.
Two randomizations will be employed, one for the expander type and the other for the cleaning method of the new expander, a computer random generator will be used to develop a simple randomization with an equal allocation ratio (1:1) and without stratification.
Data Collection and Measurements will be include, CBCT evaluation, Intraoral scan of the maxillary arch evaluation, overjet and overbite, CBCT-derived cephalometric images will be used to measure the maxillary mandibular plane angle, Microbial evaluation after using two different methods for cleaning the new clear expander and at the end of the treatment, the patient will be asked to fill out a questionnaire about the treatment, giving information about their experience and satisfaction during treatment.
Data will be analyzed using the Statistical Package for Social Sciences for Windows, version 26.0, including Descriptive Statistics 9numbers, frequencies, percentages, mean, median, and standard deviations), Reliability Statistics (an intraclass correlation coefficient), and Inferential Statistics (Levene's test, Shapiro Wilk test, Paired samples t-test and Independent samples t-test).
- Conditions
- Malocclusion, Narrow Maxilla
- Being tested
- New clear expander, Hyrax expander
- Keywords
- clear expander, hyrax, clinical trial, adolescent, thermoplastic material
- Medical subject headings
- Malocclusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
New clear expanderDevice
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.
Hyrax expanderDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| 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) Receives: 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. Receives: Device: Hyrax expander |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
Secondary outcomes (5)
Intraoral scan of the maxillary arch evaluation
Maxillary transverse dental measurements will be assessed using a digital intraoral scan. The parameters evaluated will include intercanine width, interpremolar width, intermolar width, and intermolar transpalatal width, all measured in millimeters (mm) using three-dimensional digital dental model analysis software.
Measured: pre-treatment (T0) and post-treatment (T1) around one to two months
Clinical evaluation
Overjet and overbite will be evaluated clinically using a calibrated orthodontic ruler, with measurements recorded in millimeters (mm).
Measured: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
Cephalometric analysis
CBCT-derived cephalometric images will be used to measure the maxillary mandibular plane angle in degrees (°) to evaluate the vertical relationship using cephalometric analysis software.
Measured: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
Microbial evaluation
Patients will be allocated into two groups according to the cleaning method: brushing with a toothbrush and aligner foam (China) or using Efferdent cleaning tablets (USA). Biofilm samples will be collected using sterile swabs with Amies transport medium (Boen Healthcare Co., Ltd., China). The outcome measure will be bacterial biofilm accumulation, assessed by bacteriological analysis based on bacterial colony counting, expressed as colony-forming units per milliliter (CFU/ml).
Measured: after one month.
Patient satisfaction with the appliance
At the end of treatment, patient-reported experience and satisfaction will be assessed using a structured questionnaire. Responses will be recorded as questionnaire scores using a 3-point Likert-type scale.
Measured: around one to two months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2026
- Study start1 Feb 2026
- Primary completion1 Nov 2026 (estimated)
- Study completion1 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MalocclusionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- hyrax expander clear orthodontic expander
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Baghdad
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Noor Falah Kadhim Al-Khawaja, University of Baghdad
- Investigators
- Yassir A Yassir, Ph.D. (UK), Study chair, University of Baghdad
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07362160
- Sponsor's protocol ID
- 1158425
- Other IDs
- 1158
- Acronym
- COE-Hyarx
- Status last verified
- Apr 2026
- First submitted
- 12 Jan 2026
- Last updated
- 22 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluating the Clinical Performance of a Novel Clear Orthodontic Expander Versus Hyrax: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07362160
- Acronym / sponsor ID
- COE-Hyarx / 1158425
- Conditions
- Malocclusion, Narrow Maxilla
- Keywords
- clear expander, hyrax, clinical trial, adolescent, thermoplastic material
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of BaghdadUniversity, hospital or other
- Study start
- 1 Feb 2026 (actual)
- Primary completion
- 1 Nov 2026 (estimated)
- Study completion
- 1 Feb 2027 (estimated)
- First posted
- 23 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This will be a multicenter randomize clinical trial with two-arm parallel groups, and will be conducted at the Department of Orthodontics, College of Dentistry, University of Baghdad, as well as different specialized dental centers affiliated with the Iraqi Ministry of Health, and some private clinics.
The sample size will be calculated based on previous studies with similar aim to measure the skeletal expansion. A minimum sample size of 17 patients was required, and in order to account for a 15% dropout, a total of 20 patients will be recruited for each group (new clear expander and hyrax expander). The amount of 2.5 mm or greater of maxillary sutural opening will be considered clinically effective.
Two randomizations will be employed, one for the expander type and the other for the cleaning method of the new expander, a computer random generator will be used to develop a simple randomization with an equal allocation ratio (1:1) and without stratification.
Data Collection and Measurements will be include, CBCT evaluation, Intraoral scan of the maxillary arch evaluation, overjet and overbite, CBCT-derived cephalometric images will be used to measure the maxillary mandibular plane angle, Microbial evaluation after using two different methods for cleaning the new clear expander and at the end of the treatment, the patient will be asked to fill out a questionnaire about the treatment, giving information about their experience and satisfaction during treatment.
Data will be analyzed using the Statistical Package for Social Sciences for Windows, version 26.0, including Descriptive Statistics 9numbers, frequencies, percentages, mean, median, and standard deviations), Reliability Statistics (an intraclass correlation coefficient), and Inferential Statistics (Levene's test, Shapiro Wilk test, Paired samples t-test and Independent samples t-test).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- hyrax expander clear orthodontic expander
| Arm | Type | Receives |
|---|---|---|
| New clear expander | Experimental | Device: New clear expanderAfter 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) |
| Hyrax expander | Experimental | Device: Hyrax expanderAfter 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. |
Who may qualify
- Ages
- 10 to 14 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- 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.
Key exclusion criteria (5 listed)
- Patients with obvious facial asymmetry.
- Patients with orofacial cleft.
- Patients with previous orthodontic treatment.
- Patients with bad oral habits.
- Patients with active periodontal disease.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| New clear expanderAll 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. | Device | New clear expander |
| Hyrax expanderThe 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. | Device | Hyrax expander |
Primary outcome
CBCT evaluation
Time frame: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
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.
5 secondary outcomes
Intraoral scan of the maxillary arch evaluation
Time frame: pre-treatment (T0) and post-treatment (T1) around one to two months
Clinical evaluation
Time frame: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
Cephalometric analysis
Time frame: pre-treatment (T0) and immediately post-treatment (T1) around one to two months
Microbial evaluation
Time frame: after one month.
Patient satisfaction with the appliance
Time frame: around one to two months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Yassir A Yassir, Ph.D. (UK) study chair
University of Baghdad
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing New clear expander and Hyrax expander in people with Malocclusion and Narrow Maxilla, run by University of Baghdad at 1 site in Iraq.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 22 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iraq. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Noor FK Al-Khawaja, BDS, MSc (+9647712222834, noor.alkhawaja@codental.uobaghdad.edu.iq), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
CBCT evaluation (time frame: pre-treatment (T0) and immediately post-treatment (T1) around one to two months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Apr 2026.