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.
Eligibility
Sex
ALL
Min age
6 Years
Max age
12 Years
Healthy volunteers
No
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.
Primary outcome measure(s)
Pain perception — 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.
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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