Posterior CrossbiteNCT07301918
Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite.
A study testing The Leaf expander and Hyrax expander in people with Posterior Crossbite and Maxilla; Hypoplasia, run by Cairo University at 1 site in Egypt.
Trial summary
Design: Two-arm parallel randomized clinical trial in mixed dentition (6-12 years). Arms: (1) 9 mm, 900 g leaf expander; (2) 9 mm Hyrax expander. Follow-up: From appliance insertion → completion of intended expansion → 6-month retention. Read more about this study
- Who is it for?
- Ages 6 to 12 years
- Conditions the study is for
- Posterior Crossbite, Maxilla; Hypoplasia
- What is being tested?
- The Leaf expander and Hyrax expander
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Oct 2025to Mar 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 6 to 12 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Male and female patients
- Mixed dentition stage
- Unilateral or bilateral posterior crossbite.
- Patients in prepubertal stage with cervical vertebral maturation stage 1-3.
- Fully erupted maxillary and mandibular permanent first molars.
- Skeletal class I or II.
Who cannot join
- Previous orthodontic treatment.
- Missing teeth.
- Inadequate oral hygiene.
- Patients with bad oral habits.
- Patients with medical conditions.
- Patients with cleft lip and palate.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Egypt1 site, 1 recruiting
- Recruiting
Cairo University
Cairo
Noura Saleh, Masters in Orthodontics, 122476422, noura.mohamed@dentistry.cu.edu.eg
About this study
Official title: Evaluation of the Effects of the Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite: A Randomized Clinical Trial.
Design: Two-arm parallel randomized clinical trial in mixed dentition (6-12 years).
Arms: (1) 9 mm, 900 g leaf expander; (2) 9 mm Hyrax expander. Follow-up: From appliance insertion → completion of intended expansion → 6-month retention.
Primary outcome: Pain perception during the first 7 days post-insertion (daily patient-reported scale).
Secondary outcomes: Skeletal and dental changes on CBCT.
Read the detailed description
Participants receive a banded maxillary expansion appliance cemented to maxillary first permanent molars, assigned to:
Leaf expander arm: Nickel-titanium leaf-spring expander, 9 mm screw, delivering force of ~900 g.
Hyrax expander arm: Conventional tooth-borne jackscrew expander, 9 mm screw. Standard activation: two turns per week.
Retention: Both appliances kept passively in situ for 6 months of retention following achievement of planned expansion.
- Conditions
- Posterior Crossbite, Maxilla; Hypoplasia
- Being tested
- The Leaf expander, Hyrax expander
- Keywords
- expander, maxillary transverse deficiency, posterior crossbite, mixed dentition
- Medical subject headings
- Retrognathia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
The Leaf expanderDevice
The Leaf expander incorporates Nickel Titanium springs that will not require the patients' home activation
Hyrax expanderDevice
Hyrax expander incorporates a screw that requires the patients' home activation
| Study group | Role | What they receive |
|---|---|---|
| Banded Leaf expander supported on the maxillary first permanent molars | Experimental | 9mm leaf expander delievering 900 gm force will be supported on the upper first permanent molars with the appliance arm extending to the canines Receives: Device: The Leaf expander |
| Banded Hyrax expander supported on the maxillary first permanent molars | Active comparator | 9mm Hyrax expander will be supported on the upper first permanent molars with the appliance arm extending to the canines Receives: Device: Hyrax expander |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain perception
Pain perception during the first week after insertion using Wong-Becker faces scale with minimum value of zero and maximum value of ten, ten score represents the worst pain percieved.
Measured: first week after appliance insertion
Secondary outcomes (3)
skeletal expansion
skeletal expansion using Cone Beam Computed Tomography skeletal expansion: linear distances of the midpalatal suture opening measured in mm between the pre- and post-axial cuts of the CBCT
Measured: 6 months post expansion
dental tipping
Angular measurement of upper first molars angulation measured in degrees between pre- and post-coronal cuts of the CBCT
Measured: 6 months post-expansion
digital models parameters
Intermolar width, intercanine width
Measured: six months post-expansion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Dec 2025
- Study start1 Oct 2025
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Posterior CrossbiteStudies of the same condition, open and under way.
- More trials run by Cairo UniversityThe sponsor's other registered studies.
- 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cairo University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Noura Mohamed Hamza Hassan Saleh, Cairo University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07301918
- Sponsor's protocol ID
- 24619942
- Status last verified
- Oct 2025
- First submitted
- 21 Nov 2025
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Effects of the Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite: A Randomized Clinical Trial.
- ClinicalTrials.gov ID
- NCT07301918
- Acronym / sponsor ID
- 24619942
- Conditions
- Posterior Crossbite, Maxilla; Hypoplasia
- Keywords
- expander, maxillary transverse deficiency, posterior crossbite, mixed dentition
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Cairo UniversityUniversity, hospital or other
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 24 Dec 2025 (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.
Design: Two-arm parallel randomized clinical trial in mixed dentition (6-12 years).
Arms: (1) 9 mm, 900 g leaf expander; (2) 9 mm Hyrax expander. Follow-up: From appliance insertion → completion of intended expansion → 6-month retention.
Primary outcome: Pain perception during the first 7 days post-insertion (daily patient-reported scale).
Secondary outcomes: Skeletal and dental changes on CBCT.
Detailed description
Participants receive a banded maxillary expansion appliance cemented to maxillary first permanent molars, assigned to:
Leaf expander arm: Nickel-titanium leaf-spring expander, 9 mm screw, delivering force of ~900 g.
Hyrax expander arm: Conventional tooth-borne jackscrew expander, 9 mm screw. Standard activation: two turns per week.
Retention: Both appliances kept passively in situ for 6 months of retention following achievement of planned expansion.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Banded Leaf expander supported on the maxillary first permanent molars | Experimental | Device: The Leaf expander9mm leaf expander delievering 900 gm force will be supported on the upper first permanent molars with the appliance arm extending to the canines |
| Banded Hyrax expander supported on the maxillary first permanent molars | Active comparator | Device: Hyrax expander9mm Hyrax expander will be supported on the upper first permanent molars with the appliance arm extending to the canines |
Who may qualify
- Ages
- 6 to 12 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (6 listed)
- Male and female patients
- Mixed dentition stage
- Unilateral or bilateral posterior crossbite.
- Patients in prepubertal stage with cervical vertebral maturation stage 1-3.
- Fully erupted maxillary and mandibular permanent first molars.
Key exclusion criteria (6 listed)
- Previous orthodontic treatment.
- Missing teeth.
- Inadequate oral hygiene.
- Patients with bad oral habits.
- Patients with medical conditions.
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 |
|---|---|---|
| The Leaf expanderThe Leaf expander incorporates Nickel Titanium springs that will not require the patients' home activation | Device | Banded Leaf expander supported on the maxillary first permanent molars |
| Hyrax expanderHyrax expander incorporates a screw that requires the patients' home activation | Device | Banded Hyrax expander supported on the maxillary first permanent molars |
Primary outcome
Pain perception
Time frame: first week after appliance insertion
Pain perception during the first week after insertion using Wong-Becker faces scale with minimum value of zero and maximum value of ten, ten score represents the worst pain percieved.
3 secondary outcomes
skeletal expansion
Time frame: 6 months post expansion
dental tipping
Time frame: 6 months post-expansion
digital models parameters
Time frame: six months post-expansion
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 4 Jun 2026.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing The Leaf expander and Hyrax expander in people with Posterior Crossbite and Maxilla; Hypoplasia, run by Cairo University at 1 site in Egypt.
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 6 inclusion and 6 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 4 Jun 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 Egypt. 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?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pain perception (time frame: first week after appliance insertion). 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 4 Jun 2026.