Leaf expander versus Hyrax expander for widening the upper jaw in children with posterior crossbite.
Evaluation of the Effects of the Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite: A Randomized Clinical Trial.
This trial will test whether a nickel-titanium leaf-spring expander causes less pain and achieves similar upper-jaw widening than a conventional Hyrax expander in children aged 6–12 with posterior crossbite.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 30 (estimated) |
| Ages | 6 Years to 12 Years |
| Sex | All |
| Sponsor | Cairo University Academic / other |
| Locations | 1 site (Cairo) |
| Trial ID | NCT07301918 on ClinicalTrials.gov |
What this trial studies
This is a two-arm, parallel randomized trial in mixed-dentition children comparing a 9 mm nickel-titanium leaf-spring expander (≈900 g force) with a 9 mm tooth-borne Hyrax jackscrew expander. Appliances are banded to the maxillary first permanent molars and activated until the planned expansion is reached, then left passively in place for six months of retention. The primary outcome is daily patient-reported pain during the first seven days after appliance insertion, and secondary outcomes are skeletal and dental changes measured on CBCT. Participants are prepubertal (CVM stage 1–3), have fully erupted first molars, and present with unilateral or bilateral posterior crossbite and skeletal class I or II relationships.
Who should consider this trial
Good fit: Children aged approximately 6–12 in mixed dentition with unilateral or bilateral posterior crossbite, prepubertal skeletal maturity (CVM 1–3), fully erupted maxillary and mandibular first molars, and skeletal Class I or II relationships.
Not a fit: Patients with prior orthodontic treatment, missing teeth or first molars, poor oral hygiene or bad oral habits, cleft lip/palate, systemic medical conditions, or those beyond the prepubertal stage are unlikely to be eligible or to benefit from this protocol.
Why it matters
Potential benefit: If successful, the leaf expander could reduce insertion and early activation pain while delivering comparable maxillary expansion, making treatment more comfortable for children.
How similar studies have performed: Smaller clinical series and some comparative studies have reported effective expansion and reduced early discomfort with spring-based leaf expanders versus conventional Hyrax devices, but high-quality randomized evidence remains limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 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. Exclusion Criteria: * Previous orthodontic treatment. * Missing teeth. * Inadequate oral hygiene. * Patients with bad oral habits. * Patients with medical conditions. * Patients with cleft lip and palate.
Where this trial is running
Cairo
- Cairo University — Cairo, Egypt (Recruiting)
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.