Abstract: cyst is a Pathological cavity containing solid ,liquid,gases substance but not by the pus which does not always with epithelial lining. its is a pathological lesion ,even it is a bengin it required a attention ,large cyst may cause the destruction and displacement of the anatomical structure.killey and kay gave a definition of the cyst in 1966 that was modified by Kramer in 1974 due to the modification found in epithelial lining by Kramer in1974. The treatment planning of the cyst in oral cavity is various according to the location,size and the involvement of the structure that occurs.