The main objective of this randomised clinical trial is to is to compare the frequency of recurrence between patients who received nasal spray calcitonin after curettage of Central Giant Cell Granuloma and without it.

A total of 24 patients with aggressive Central Giant Cell Granuloma (CGCG )will be selected . All examinations were performed by calibrated clinicians and gender, age, medical history, symptoms, lesion size and site, disease duration and form of treatment were recorded for all participant. Radiographic examination with cone beam computed tomography (CBCT) and panoramic radiograph was done for all patients. All patients were randomly assigned to one of two treatment groups; 2 weeks after the biopsies were taken.

The case group (n =12 with) underwent 200 IU/day ones a day for 3 months after the surgeries. conservative curettage surgical procedure was done for them. while placebo was treated by curettage of CGCGs and received a placebo ones a day for 3 months after surgeries.. Patients were followed up by a maxillofacial surgeon who did not participated in surgeries.None of surgeons did not aware about the research before and during the operations.Patients were blinded from the drugs which they received after surgeries.

All patients were follow up for 5 years after operations. Recurrence lesions were documented by clinical and radiographical examinations and proved by histopathological evaluation.

Inclusion Criteria:

• clinical and histopathological diagnosis of aggressive CGCG based on accepted criteria established by chuong etal normal level of calcitonin and serum Parathyroid hormone(PTH) Patients of both sexes between 13 to 30 year's old Patients who gave written informed consent Patients who were willing for evaluation in the fallow up session Primary size of the lesion should be more than 5 cm in CBCT

Exclusion Criteria:

• Participants demonstrating a systemic disease which affects bone healing,brown tumor ,pregnancy , recently corticosteroid therapy , previous surgical intervention for CGCG or refused study enrollment and whom they could not continue the study for private or social reasons were excluded from the study sample.