Leaf Expander Versus Hyrax Expander in Mixed Dentition Patients With Posterior Crossbite.

Cairo University (CU)

Status: Not yet enrolling

Conditions: Posterior Crossbite; Maxilla; Hypoplasia

Treatments: Device: Hyrax expander; Device: The Leaf expander

Study type: Interventional

Funder types: Other

Identifiers

NCT07301918

24619942

Details and patient eligibility

About

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.

Full 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.

Enrollment: 30 estimated patients

Sex: All

Ages: 6 to 12 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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30 participants in 2 patient groups

Banded Leaf expander supported on the maxillary first permanent molars

Experimental group

Description:

9mm leaf expander delievering 900 gm force will be supported on the upper first permanent molars with the appliance arm extending to the canines

Treatment:

Device: The Leaf expander

Banded Hyrax expander supported on the maxillary first permanent molars

Active Comparator group

Description:

9mm Hyrax expander will be supported on the upper first permanent molars with the appliance arm extending to the canines

Treatment:

Device: Hyrax expander