Early orthodontic treatment of Class III malocclusions with skeletal and dentoalveolar imbalances, represents a continuous dilemma. This difficulty starts from their meticulous diagnosis and treatment planning till reaching satisfactory results and finally stability. Some appliances could be used to correct growing skeletal Class III patients, improving the skeletal and dentoalveolar relationships, creating proper conditions for final orthodontic treatment, more importantly avoiding surgery. These appliances remove patient compliance from the equation.

Aim of the work: Evaluate the skeletal, dentoalveolar and soft tissue effects of two different force application systems which are the pulling force (CS 2000® appliance/ CS appliance) and the pushing force (Reversed Forsus fatigue-resistant device/ RF appliance).

Materials and methods: A randomized controlled clinical trial will be conducted to address the aim of the study. Thirty three growing skeletal Class III patients (9-11 years) will be recruited upon a lateral cephalometric x-ray. Subjects complying with the inclusion criteria will be randomly assigned using a computer-generated list to one of the three groups Group I: Eleven patients treated with CS2000 appliance, Group II: Eleven patients treated with reversed Forsus Fatigue Resistant device and Group III: control group of Eleven untreated patients with a ratio of 1:1:1 allocation. A CBCT will be made before installing the appliances. After gaining a 2 mm positive overjet or a 6 months period, alginate impressions will be poured and dental casts will be made. Photographs and CBCTs will also be performed to record the dentofacial effect of the used appliances.

Keywords: Cone beam computed tomography, growing skeletal Class III, CS 2000® appliance, Reversed Forsus Fatigue resistant device.

Inclusion Criteria:

• Age range from 8 years to 11 years.
• Cervical vertebrae maturation index (CVMI 2 and 3) identified on the lateral cephalometric radiograph.
• Angle Class III molar relation.
• Skeletal class III ANB ranges between (-4) - (0).
• Wits appraisal ranges between (0) - (-5).
• Patients with good oral hygiene, and a healthy periodontal condition.
• Reversed over jet (-1) - (-6).
• Normal vertical growth pattern (SN/MP angle 28˚-38˚).

Exclusion Criteria:

• A discrepancy between centric relation and maximum intercuspation.
• Patients who underwent previous orthodontic treatment.
• Patients currently receiving drug therapy that may affect orthodontic tooth movement.
• Congenitally missing teeth or extracted teeth.
• History of systemic disease or craniofacial syndromes or presence of cleft.

TREATMENT OF GROWING SKELETAL CLASS III PATIENTS

Participants and statistician will be blinded (double blind) to the intervention group. After data collection is completed, the randomization code will be broken to reveal the allocation group. The operator will be blinded during recording of the measurements.