Actively Recruiting
Evaluation of the Effects of the Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite: A Randomized Clinical Trial
Led by Cairo University · Updated on 2026-06-04
30
Participants Needed
1
Research Sites
N/A
Total Duration
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AI-Summary
What this Trial Is About
This research evaluates two types of maxillary expansion devices in children aged 6 to 12 years with posterior crossbite and mixed dentition. The trial compares a leaf expander using nickel-titanium springs with a traditional Hyrax expander that requires manual activation. The study aims to assess differences in pain experienced during the first week after device insertion and observe skeletal and dental changes over time. Conducted as a randomized clinical trial, the study is sponsored by Cairo University. Participants receive an appliance cemented to their upper first permanent molars. One group uses a 9 mm leaf expander delivering approximately 900 g of force without requiring home adjustments. The other group uses a 9 mm Hyrax expander with a screw that participants activate twice weekly. After achieving the planned expansion, both devices remain passively in place for a 6-month retention period to maintain the correction. Throughout the study, children report daily pain levels for the first 7 days following insertion. Researchers also use imaging and digital models to measure skeletal expansion, dental tipping, and other parameters six months after expansion completion. The total follow-up period includes initial treatment and retention, with ongoing assessments to monitor outcomes and device effects.
CONDITIONS
Brief Title
Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite.
Who Can Participate
Eligibility Criteria
You may qualify if you...
- 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
You will not qualify if you...
- Previous orthodontic treatment
- Missing teeth
- Inadequate oral hygiene
- Patients with bad oral habits
- Patients with medical conditions
- Patients with cleft lip and palate
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Appliance activation and adjustment period of approximately 1 week
Participants receive a banded maxillary expansion appliance cemented to the upper first permanent molars, either the Leaf expander or the Hyrax expander.
1 visit for appliance insertion and activation
Duration - Until planned expansion is achieved, typically within a few weeks
Participants undergo maxillary expansion with their assigned appliance. The Leaf expander uses a nickel-titanium spring that does not require home activation. The Hyrax expander requires home activation with two turns per week.
Weekly visits until expansion completion
Duration - 6 months
After achieving planned expansion, the appliance is kept passively in place for retention to stabilize the expansion.
Regular follow-up visits during retention period
Trial Site Locations
Total: 1 location
1
Cairo University
Cairo, Egypt
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
OTHER
Number of Arms
2
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