in the present study, the effect of PRP on bone regeneration when applied to the site of removal of cyst of the jaws is evaluated. PRP was delivered to the site combined with gelfoam. Thrombin clot accelerator was not used.

Jaw cysts are common lesions in the oral and maxillofacial region. Enucleation of cyst wall & curettage has evolved as the treatment of choice. In order to reduce infections and to accelerate bone regeneration, by using of Platelet rich plasma.

Platelets are involved in regeneration at sites of pathology, apart from their role in clotting. A preparation composed mainly of platelets (platelet-rich plasma gel) applied to sites of bony pathology, after surgical treatment of lesions, may hasten bone regeneration.

An interesting idea developed that the addition of a concentrate of platelets, to wounded tissues or surgical sites, may enhance the body's natural wound healing mechanisms . Platelet-rich plasma (PRP) is the accepted term to describe the preparation made out of autologous platelets suspended in autologous plasma, in concentration greater than normally found in peripheral blood Because it is autologous, PRP avoids the risk of transmissible diseases such as HIV, Hepatitis B, C or D and other blood-borne pathogens .A clot accelerator such as bovine thrombin is added to gel the PRP or PRP is added to other materials such as collagen, gelfoam, etc.

Inclusion Criteria:

1. Size of the cyst more than 2 cm
2. The lesion could be visualized radiographically
3. Patients within the age range of 20 to 50 years

Exclusion Criteria:

1. Patients who were alcoholics & smokers
2. -Patients with systemic diseases
3. History of bleeding tendencies, blood dyscrasia
4. Low platelet count
5. Patients unable or unwilling to return for follow-up