evaluate the effect of periodontal distractor with and without interseptal bone cuts on the displacement of the maxillary canines, to assess the effect of two approaches on the pain intensity and on the pulp vitality of the retracted canines.

The sample of the study consisted of 32 canines in 16 female patients (16- 21 years old) requiring extraction of bilateral maxillary first premolars and canine retraction. They were divided into two groups: canine retraction was done by buccal periodontal distractor with distal interseptal bone cuts (Group I), canine retraction was done by buccal periodontal distractor without distal interseptal bone cuts (Group II). After bilateral maxillary premolar extraction in both groups inter septal bone cuts was done in group I only. Then the periodontal distractor was cemented and activated twice per day in both groups. Rate of canine retraction was evaluated before and after complete canine retraction direct in patient's mouth with digital caliper. Pain intensity was evaluated at 1st ,2nd ,4th and 7th days after activation through visual analog scale (VAS). An electrical vitality test was evaluated before and after the distraction procedure.

Inclusion Criteria:

• Patient age: 16-21 years.
• patients required bilateral extraction of maxillary first premolars followed by maxillary canine retraction (class I malocclusion as excessive overjet, bimaxillary protrusion, class II malocclusion).
• The dentition didn't exhibit any gross anatomic root anomalies as assessed from panoramic radiographs.
• No systemic disease that may affects the bone.
• No periodontal disease.
• Good oral hygiene.
• Very good patient compliance.
• Absence of any previous orthodontic treatment.

Exclusion Criteria:

• The dentition exhibit any gross anatomic root anomalies as assessed from panoramic radiographs.
• Cases with deep carious lesions or endodontic lesions involving the maxillary canines and buccal segments.
• Cases with severly rotated or grossly malpositioned canines.
• Systemic disease that may affects the bone.
• Periodontal disease and poor oral hygiene.
• Presence of previous orthodontic treatment.