This study will evaluate the effect of locally applied Calcitriol on dental and skeletal changes during upper canine retraction. It is a split-mouth randomized clinical trial, where Calcitriol will be locally applied on one side of the maxilla, and the other side will serve as control.

Orthodontic tooth movement depends on bone remodeling. This study investigates if Calcitriol, the active form of vitamin D3, can affect this process when applied locally during upper canine retraction. The study is designed as a split-mouth randomized clinical trial. Patients needing maxillary first premolar extraction will be included. Calcitriol will be locally applied on one side, and the other will serve as a control. The study will evaluate dental and skeletal changes to see if Calcitriol improves treatment outcomes.

Inclusion Criteria:

1. Presence of class I malocclusion requiring bilateral extraction of the maxillary first premolars and subsequent canine retraction.
2. Presence of class II malocclusion requiring bilateral extraction of the maxillary first premolars and subsequent canine retraction.
3. Age range between 13 and 35 years to include both adolescent and adult patients suitable for orthodontic treatment.
4. Presence of permanent dentition.
5. Good oral hygiene.

Exclusion Criteria:

1. History of chronic systemic disease.
2. Presence of active gingival or periodontal disease.
3. Known allergy or hypersensitivity to vitamin D.
4. Pregnancy or lactation.
5. History of previous orthodontic treatment.
6. Presence of craniofacial anomalies affecting bone physiology.

This is a university-based academic study conducted as part of a master's thesis. There is no plan to share individual participant data due to the absence of a data-sharing agreement or external funding