Aneurysmal bone cyst, unlike ossifying fibroma and fibrous dysplasia, occurs less frequently in the jaw bones than in the long bones and usually involves the mandible rather than the maxilla.Eighty percent of aneurysmal bone cysts occur in patients younger than 30 years of age; both sexes are equally affected. Microscopically, curetted material from the cavity resembles giant cell reparative granuloma but has more prominent vascular spaces, with evidence of old and recent hemorrhages and thrombosis and hyalinization of some of the vascular spaces. Like giant cell granuloma, it has no epithelial lining despite the common use of the word “cyst” to describe it. Aneurysmal bone cyst is to be differentiated from two other pseudocysts of the jaw: the so-called traumatic bone cyst
(the name given to solitary and usually asymptomatic cavities that are found in the mandible, that are without any epithelial or other distinguishing lining and that contain only serum or are apparently empty), for which a traumatic etiology seems to be less convincingly established, and the submandibular salivary gland depression (static or latent bone cyst, or Stafne’s cyst), located below the inferior mandibular canal just anterior to the angle of the mandible, where it presents as a well-delineated radiolucency that may contain salivary gland tissue.A similar defect can be seen in the anterior mandible apical to the canine, where the sublingual gland resides, and is termed a sublingual salivary gland depression. For both the aneurysmal and traumatic bone cysts, a thorough curettage of the lesion and its walls and packing with bone chips result in the healing of the defect.