Definition :• intraosseous lesions in which there is replacement of normal bone by tissuecomposed of collagen , fibers & fibroblasts that contain varying amounts of mineralized substances , which may beosseous or cementum-like in appearance .
1- solitary bone cyst• The traumatic bone cyst (TBC) is an uncommon nonepithelial lined cavity of the jaws.• The lesion is mainly diagnosed in young patients most frequently during the second decade of life.• The majority of TBCs are located in the mandibular body between the canine and the third molar.• Clinically, the lesion is asymptomatic in the majority of cases and is often accidentally discovered on routine radiological examination usually as an unilocular radiolucent area with a "scalloping effect".• The definite diagnosis of traumatic cyst is invariably achieved at surgery. Since material for histologic examination may be scant or non-existent, it is very often difficult for a definite histologic diagnosis to be achieved..
Preoperative panoramic X-ray showing the left lower semi-impacted 3rd molar. Panoramic X ray taken four years later showing a unilocular radiolucent area in the left ramus.
CT scans showed a cyst like low density area in the left ramus region. CT scans showed a cyst like low density area in the left ramus region.
Normal appearing bone spicules with parts of vascular connective tissue (haematoxylin-eosin, original magnification × 40). Higher magnification (haematoxylin-eosin × 160).
2- Gigantiform cementoma• Gigantiform cementoma is a rare, benign fibro-cemento-osseous disease of the jaws, seen most frequently in young girls.• Radiographically, it typically presents as multiquadrant, expansile, mixed radiolucent-opaque lesions that cross the midlines of the jaws.• Although cases with a familial pattern are noted in a few publications, sporadic cases have been reported without a family history.
(a) Massive mixed radiolucent/radioopaque expansile lesions in both jaws. (b) Fibro-osseous pattern with cementicles and boney trabecuae, the former often appearing much larger that those seen in cemento-ossifying fibroma
3- cherubism• It is a autosomal dominant fibro-osseous• *benign hereditary condition which affects only the jaw bones and it is• characterized by “bilaterally symmetrical enlargement” of mandible sometimes maxilla
Cherubism is a hereditary disease which is histologically similar to Central Giant cell granuloma
1- aneurysmal bone cyst• Aneurysmal bone cyst (ABC) is an uncommon non- neoplastic lesion of the bones, usually affecting the long bones and spine.• The rare jaw lesions are encountered in the body and ramus of the mandible.• Commonly reported in the second and third decades of life,• ABCs are characterized by a rapid growth pattern with resultant bony expansion and facial asymmetry.• Surgical management usually consists of surgical curettage or resection.• The treatment of aneurysmal bone cyst is complete surgical excision of the lesion.• Sometimes, the lesion regresses even after incomplete removal. Prognosis is excellent and recurrences are rare.
Aneurysmal bone cyst. Expansile multilocular "soap bubble"-like osteolysis with soft tissue extension transversed by intralesional bony septa.Although barely visible, the extraosseous component is well-delineated. Root resorption of included teeth.
Prominent osteoblastic activity is seen along anastomosing bony trabeculae
2- central giant cell granuloma• (CGCG) is a benign lesion of the jaws with an unknown etiology.• Clinically and radiologically, a differentiation between aggressive and non-aggressive lesions can be made.• The incidence in the general population is very low and patients are generally younger than 30 years.• Histologically identical lesions occur in patients with known genetic defects such as cherubism, Noonan syndrome, or neurofibromatosis type 1.• Surgical curettage or, in aggressive lesions, resection, Is the most common therapy.
3- Garres osteomylitis• Inflammatory periosteal hyperplasia• -Periosteal reaction to inflammation: forms several rows of reactive vital bone parallel to each other.• -Primarily in children and young adults (avg~13 yrs)• -Most frequent cause: caries w/ assoc Periapical disease
4- osseous dysplasia• periapical OD/COD: dysplastic lesions occurring in the anterior mandible and involving only a few adjacent teeth• focal OD/COD: similar to periapical OD/COD, but with the limited number of lesions occurring in a posterior jaw quadrant (rather than in the anterior mandible)• florid OD/COD and familial gigantiform cementoma: more extensive forms, occurring bilaterally in the mandible or in all jaw quadrants
1- benign cementoblastoma• The benign cementoblastoma is a relatively rare odontogenic neoplasm of the jaws• The lesion is considered as the only true neoplasm of cementum origin• generally occurs in young persons, comprises less than 1% to 6.2% of all odontogenic tumours• characterized as being attached to the roots, most frequently tends to be associated with an erupted permanent tooth, most often the first molar or second premolar in the lower jaw: only rarely has an association with an impacted or partially impacted tooth been reported• The recommended treatment is complete enuclation of the tumor mass with extraction of the involved tooth
2- ossifying fibroma• Ossifying fibroma develops from the multipotential mesenchymal cells of periodontal origin which are able to form both bone and cementum. Although the precise pathogenesis is still unknown, it has been suggested that trauma induced stimulation may play a role.• Juvenile ossifying fibroma is a fibro-osseous neoplasm that arises within the craniofacial region in young individuals below 15 years of age.• It is described in the World Health Oraganisation histological typing of odontogenic tumours as an actively growing lesion consisting of a cell rich fibrous stroma, containing bands of cellular osteoid without osteoblastic lining, together with trabeculae of more typical woven bone. Small foci of giant cells may also be present.• The lesion is non – encapsulated but well demarcated from surrounding bone
3- osteoid osteoma• Osteomas are benign, slow-growing osteogenic tumours rarely occurring in the craniofacial bones.• Osteomas are characterised by the proliferation of compact and/or cancellous bone.• It can be of a central, peripheral, or extra skeletal type.• The peripheral type arises from the periosteum and is rarely seen in the mandible.• The lingual surface and lower border of the body are the most common locations of these lesions.• They are usually asymptomatic and can be discovered in routine clinical and radiographic examination.
- Limited growth pattern (1.5- 2.0 cm).- Sharp circumscription near cortical surface (forming nidus).- Composed of anastomosing bony trabeculae with variable mineralization.- Bony trabecules lined by plump osteoblast.- Vascularized connective tissue: surrounded by sclerotic bone.- Benign giant cells may be present.
4-Osteoblastoma• Benign osteoblastoma is an uncommon, solitary, osteoid and bone-producing tumor which is characterized by prevalent active osteoblasts and rich vascularized delicate fibrous stroma, previously regarded as malignant.• The term benign osteoblastoma was recently proposed by different authors to separate this lesion from other solitary benign bone tumors.• It most often involves long bones and vertebral column and other bones, and also occurs in jaw bones.• There is a close histopathologic similarity between benign osteoblastoma and osteoid osteoma; consequently, much debate about them exists.• Benign osteoblastoma has a good prognosis and is best treated by curettage or conservative surgical excision. Recurrence is rare.
Cellular connective tissue containing delicate collagen fibres and irregular bone-like trabeculae.Plump osteoblasts and multinucleated osteoclasts are present on the trabeculae.
Radiolucent lesion with small calcifications and irregular, indistinct margins in the 33-46 area.
brown tumor of hyperparathyroidism• excess secretion of parathyroid hormone due to parathyroid hyperplasia compensating for a metabolic disorder that has resulted in retention of phosphate or depletion of the serum calcium level.• The radiologic features of both forms of hyperparathyroidism are similar. These include generalized osteoporosis, unilocular or multilocular cystic radiolucencies in bone (Brown tumor), attenuation or loss of lamina dura surrounding the teeth, and calcifications in muscles and subcutaneous tissues.• It is often considered that histopathologic study of a biopsy specimen is the basis for diagnosis of "cystic" lesions of the jaws• . Unfortunately, the Brown tumor provides no definitive histologic answer. Nuclear medicine or serologic confirmation is usually needed.
fibrous dysplasia• non-neoplastic, primary disorder of bone in which normal medullary bone is replaced by a variable amount of structurally weak fibrous and osseous tissue.
Pagets disease• a chronic progressive disease of the bone characterized by abnormal bone resorption and deposition affecting either single bone (monostotic) or many bones (polyostotic) with uncertain etiology.• Clinical symptoms include pain, deformity, and may lead to fracture of the affected bone, even though the initial course of the disease may be asymptomatic.• The enlarged and deformed bones may compress surrounding nerves and vessels causing neurological symptoms like hearing loss; inexplicably, it is quite unusual in the facial bones.• Facial disfigurement may be consequence of enlargement of the maxilla and/or mandible• Therapeutic agents commonly used include calcitonin, bisphosphonate, and mithramycin. A recent clinical trial suggested that second and third generation bisphosphonate, such as pamidronate and alendronate, were more effective than calcitonin and editronate, the first generation bisphosphonate.