NCT07301918

Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients 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.

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: Cairo University · Academic / Other
• Sex: All
• Age: 6 Years – 12 Years
• Healthy volunteers: Not accepted

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. 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.

Conditions

• Posterior Crossbite
• Maxilla; Hypoplasia

Interventions

Type	Name	Description
DEVICE	The Leaf expander	The Leaf expander incorporates Nickel Titanium springs that will not require the patients' home activation
DEVICE	Hyrax expander	Hyrax expander incorporates a screw that requires the patients' home activation

Timeline

• Start date: 2025-10-01
• Primary completion: 2027-03-01
• Completion: 2027-03-01
• First posted: 2025-12-24
• Last updated: 2026-03-18

Locations

1 site across 1 country: Egypt