Patients at the Orthodontic Department of the University of Damascus Dental School will be examined and subjects who meet the inclusion criteria will be included. Then, initial diagnostic records (diagnostic gypsum models, internal and external oral photographs, and radiographic images) will be studied to ensure that the selection criteria are accurately matched.

This study aims to compare two groups of patients with moderate crowding of the lower anterior teeth. Experimental group: the patients in this group will be treated with periodontally accelerated osteogenic orthodontics Control group: the patients in this group will be treated using fixed appliances without any acceleration method.

Correction of irregular teeth can take a long time, and this depends on various factors such as the good compliance of the patient, the amount of dental crowding, and the need for extraction in the course of orthodontic treatment.

Many methods have been used to accelerate tooth movement, and recently the PAOO technique has emerged as an effective therapeutic intervention.

PAOO is a promising procedure but only a few cases were reported in the literature. Controlled clinical and histological studies are needed to understand the biology of tooth movement with this procedure, the effect on teeth and bone, post-retention stability, measuring the volume of mature bone formation, and determining the status of the periodontium and roots after treatment.

Inclusion Criteria:

• skeletal class I malocclusion (ANB=2-4)
• normal vertical growth pattern.
• moderate crowding of lower anterior teeth (i.e., 4-6 millimeters of a tooth size-arch length discrepancy)
• 1 to 3 mm of overjet and 1 to 4 mm of the overbite
• good oral health

Exclusion Criteria:

• medical, social, and psycho contraindications to oral surgery
• presence of periodontal diseases
• poor oral hygiene
• previous orthodontic treatment