Inclusion Criteria:  Patients requiring 1st premolar extraction (e.g bimaxillary dentoalveolar protrusion) Erupted full set of permanent teeth (excluding 3rd molars)  Exclusion Criteria:  Systemic diseases that would interfere with bone metabolism Craniofacial syndromes congenitally missing or extracted permanent teeth. periodontally compromised patients smokers pregnant women previous orthodontic treatment