This study aims at evaluating the effects of mandibular advancement on pharyngeal airway space and nocturnal breathing in children with skeletal class II division1 malocclusion. Fifty patients will be enrolled in the study divided into control and experimental groups.

The purpose of the present research is not only evaluate the effect of functional appliance on the pharyngeal airway space, but also evaluate its effect on nocturnal breathing of children with skeletal class II.

Inclusion Criteria:

1. Skeletal class II division 1 malocclusion due to mandibular retrognathism.
2. Cephalometric angular measurements: SNA ≥ 82, SNB ≤ 78, ANB ≥ 4.
3. Overjet ≥ 6 mm.
4. Patient in circumpubertal stage CVM2 and CVM3.

Exclusion Criteria:

1. History of orthodontic treatment.
2. Presence of craniofacial anomalies or TMJ disorders.
3. Systemic problems that may affect craniofacial growth.
4. Abnormal oral habits.

Will be based on the facility regulations and approval.

Data will be available at the end of the study i.e after 2 years.

Data will be available through the principle investigator and the study chair.