Fibro-osseous lesions of the jaws

definition,classification,FD,OF, PCOD, conclusion, references

1. Fibro- Osseous Lesions of the jaws PRESENTER: Dr.Sachidanand giri Jr-3

2. CONTENTS Introduction Classifications Fibrous dysplasia Ossifying fibroma Cemento - osseous dysplasia Central giant cell granuloma Cherubism Aneurysmal bone cyst Solitary bone cyst

3. INTRODUCTION “ The term fibro-osseous lesion ( fol ) is a generic designation of a group of jaw disorders” characterized by the replacement of bone by a benign connective tissue matrix. This matrix displays varying degrees of mineralization in the form of woven bone or of cementum -like round acellular intensely basophilic structures. Describe only a process.

4. Early-stage lesions : fibroblast-like cells in proliferating fibrous connective tissue with interspersed areas of mineralization. Mature lesions: the degree of mineralization increases to dense, sclerotic, acellular , avascular mineralized tissue. The histologic patterns: ubiquitous. The lesions may be developmental( hammartomatous ), reactive, dysplastic or neoplastic .

5. Benign fibro-osseous lesions ( bfol ) of the jaw, facial and skull bones are a variant group of intra-osseous disease processes that share microscopic features. Whereas some are diagnosable histologically , most require A combined assessment of clinical, microscopic and radiologic features.

6. Charles Waldron wrote “ In absence of good clinical and radiologic information a pathologist can only state that a given biopsy is consistent with a FOL. With adequate clinical and radiologic information most lesions can be assigned with reasonable certainty into one of several categories”.(1985)

7. CLASSIFICATION Since 1930’s, numerous classifications have been proposed and varieties of lesions have come under the umbrella of fibro-osseous lesion, which includes developmental lesions, reactive lesions, and benign fibro-osseous neoplasm. 1.Waldron (1985): I . Fibrous dysplasia ( fd ) A. Polyostotic B. Monostotic

8. II. Fibro-osseous ( cemental ) lesions presumably arising in the periodontal ligament Periapical cemental dysplasia B. Localized fibro-osseous- cemental lesion (probably reactive in nature) C. Florid cement-osseous dysplasia ( gigantiform cementoma ) D. Ossifying and cementifying fibroma III. Fibro-osseous neoplasms of uncertain or debatable relationship to those arising in the periodontal ligament A. Cementoblastoma, osteoblastoma and osteoid osteoma B. Juvenile active ossifying fibroma and other so-called aggressive, active ossifying/ cementifying fibromas .

9. 2.Modified Classification by Waldron,1993 1 . Fibrous dysplasia 2. Cemento -osseous dysplasia a. Periapical cemento -osseous dysplasia b. Focal cemento -osseous dysplasia c. Florid cemento -osseous dysplasia 3. Fibro-osseous neoplasm a. Cementifying /ossifying / cemento -ossifying fibroma .

10. 2.WHO Classification of Fibro-osseous Lesions of Jaws (2005) 1) Ossifying Fibroma (OF) 2) Fibrous Dysplasia 3) Osseous Dysplasia a. Periapical Osseous Dysplasia b. Focal Osseous Dysplasia c. Florid Osseous Dysplasia d. Familial Gigantiform Cementoma 4) Central Giant Cell Granuloma 5) Cherubism 6) Aneurismal Bone Cyst 7) Solitary Bone Cyst

11. 3.Eversole (2008): I . Bone dysplasia A. Fibrous dysplasia i . Monostotic ii. Polyostotic iii. Polyostotic with endocrinopathy (McCune-Albright) iv. Osteofibrous dysplasia B. Osteitis deformans C. Pagetoid heritable bone dysplasia of childhood D. Segmental odontomaxillary dysplasia II. Cemento -osseous dysplasia A. Focal cemento -osseous dysplasia B. Florid cemento -osseous dysplasia

12. III . Inflammatory/reactive processes A. Focal sclerosing osteomyelitis B. Diff use sclerosing osteomyelitis C. Proliferative periostitis IV. Metabolic disease: Hyperparathyroidism V. Neoplastic lesions (Ossifying fibromas ) A. Ossifying fibroma NOS B. Hyperparathyroidism jaw lesion syndrome C. Juvenile ossifying fibroma i . Trabecular type ii. Psammomatoid type D. Gigantiform cementomas ( International Journal of Contemporary Dental and Medical Reviews (2014), Article ID 071214, 5 Pages)

13. FIBROUS DYSPLASIA A benign, self-limiting, but nonencapsulated lesion occurring mainly in young subjects, usually in the maxilla, and showing replacement of the normal bone by a cellular fibrous connective tissue containing islands or trabeculae of metaplastic bone. First reported by von recklinghausen in 1891. The term fibrous dysplasia was first mentioned by lichtenstein in 1938 .

14. Fibrous dysplasia is a benign intramedullary fibro-osseous lesion originally described by lichtenstein in 1938 and by lichtenstein and jaffe in 1942. This is a benign dysplastic process of altered osteogenesis that may occur within a single bone ( monostotic ) or multiple bones ( polyostotic ),2 and is best understood as a dysplastic anomaly of bone forming mesenchymal tissue . 5% to 7% of benign bone tumors.

15. Etiology and Pathophysiology The exact cause of fibrous dysplasia is not known. It is classified by W.H.O. as developmental in origin. Fibrous dysplasia is postulated to occur as a result of a developmental failure in the remodeling of primitive bone to mature lamellar bone and a failure of the bone to realign in response to mechanical stress. Failure of maturation leaves a mass of immature isolated trabeculae enmeshed in dysplastic fibrous tissue that are turning over constantly but never (or very, very slowly) completing the remodeling process.

16. In addition, the immature matrix does not mineralize normally. The combination of a lack of stress alignment and insufficient mineralization results in substantial loss of mechanical strength, leading to the development of pain, deformity, and pathologic fractures .

17. THE ETIOLOGY HAS BEEN LINKED WITH A MUTATION IN THE GNAS1 GENE LOCATED AT CHROMOSOME 20Q13.2 GNAS1 (GUANINE NUCLEOTIDE BINDING PROTEIN) GENE ENCODES A G - PROTEIN MUTATION RESULTS IN THE CONTINUOUS ACTIVATION OF THE G - PROTEIN OVERPRODUCTION OF C-AMP IN AFFECTED TISSUES. HYPERFUNCTION OF CELLS AND ORGANS

18. HYPERFUNCTIONS

19. Classification 1 . Monostotic fibrous dysplasia 2. Polyostotic fibrous dysplasia Jaffe's lichtenstein syndrome Mccune - albright syndrome. 3. Craniofacial form 4. Cherubism

20. MONOSTOTIC FIBROUS DYSPLASIA A single bone About 70% to 80%

21. Bony hamartoma made up of an over abundance of fibrous connective tissue replacing normal bone marrow. Age:5 to 70 years, but more common under 30 years of age. Abnormal differentiation of osteoblasts . Maxilla, mandible, frontal, sphenoid and zygoma are the most commonly affected craniofacial bones.

22. CLINICAL FEATURES M:f= 1:1 Swelling involves buccal and labial plate and seldom the lingual plate. Painless and slow growth Occurs in rib (28%) > femur (23%) > tibia > craniofacial bones (10-25%) > humerus . Low plateau, nodular,or dome shaped Firm smoothly contoured, covered with normal mucosa.

23. Oral manifestations : Mal-alignment of teeth. Tipping or displacement of teeth due to progressive expansile lesion. Tenderness is a late feature.

24. POLYOSTOTIC FIBROUS DYSPLASIA two or more bones. A relatively uncommon condition. 20-30% of FD. few to 75% of the entire skeleton. Affects multiple bones like jaws, femur, tibia, pelvis, ribs, skull, clavicle and facial bones. 2 types: Jaffe's lichtenstein syndrome Mccune albright's syndrome

25. Jaffe's lichtenstein syndrome FD, accompanied by pigmented lesions of the skin or "cafe-au- lait " spots of thin light brown color. Mild and non- progressive form. Occurs in about 50% of the cases. Café au lait spots: Flat, pigmented birthmarks Caused by a collection of pigment-producing melanocytes in the epidermis of the skin.

26. M c Cune-Albright syndrome Fuller albright first described this syndrome in 1937. Mccune albright syndrome is defined as the association of Polyostotic fibrous dysplasia, Precocious puberty, Caf ѐ- au- lait spots, and Other endocrinopathies due to hyperactivity of various endocrine gla nds.

27.   Mc CUNE ALBRIGHT SYNDROME NEUROFIBROMATOSIS NEVER CROSS MIDLINE CROSS THE MIDLINE IRREGULAR BORDERS SMOOTH BORDERS COAST OF MAINE COAST OF CALIFORNIA

28. CLINICAL FEATURES 20-30 % cases of FD . It most commonly occurs in childhood. Age: 8-10 years , Structural integrity of the bone is weakened Weight bearing bones become bowed The curvature of the femoral neck and proximal shaft of the femur markedly increase causing a 'shepherd crook deformity ', which is a characteristic sign of the disease. Complication: spontaneous fractures

29. ORAL MANIFESTATIONS OF FIBROUS DYSPLASIA

30. Mazabraud's syndrome Rare disease association of FD and intramuscular myxoma . greater risk of sarcomatous transformation in fd with mazabraud's syndrome. Females may have a greater risk for breast cancer(elevated estrogen level) Etiology: GS alpha gene mutation.

31. CRANIOFACIAL FIBROUS DYSPLASIA Confined to a single anatomical site. Primarily the maxilla. May also cross sutures into the sphenoid, zygoma , frontonasal bones and base of the skull.

32. CLINICAL FEATURES 10-25% of patients with the monostotic form 50% with the polyostotic form. Occurs during 1st and 2nd decades. Common sites of involvement are frontal, sphenoid, maxillary and ethmoid bones.

33. involvement of orbital and periorbital bones Headache Hypertelorism , Cranial asymmetry, Facial deformity, Visual impairment, Exopthalmos AND blindness.

34. INVOLVEMENTOF ethmoid bone or frontal bone : a narrowing and displacement of the orbital cavity. INVOLVEMENTOF nasal and paranasal cavities : lead to respiratory impediments

35. Radiographic Features LOCATION: Maxilla>mandible unilateral PeriphEry : Most commonly is ill defined, with a gradual blending of normal trabecular bone into an abnormal trabecular pattern.

36. Internal structure. The internal aspect of bone may be more radiolucent, more radiopaque , or a mixture of these two variations compared with normal bone .

37. The internal density is more radiopaque in the maxilla and the base of the skull. Early lesions may be more radiolucent than mature lesions and in rare cases may appear to have granular internal septa, giving the internal aspect a multilocular appearance.

38. . The abnormal trabeculae usually are shorter, thinner, irregularly shaped, and more numerous than normal trabeculae . This creates a radiopaque pattern that can vary; it may have a granular appearance ("ground-glass" appearance,), an orange-peel ( peau d'orange ), a wispy arrangement (cotton wool), or an amorphous, dense pattern.

39. A distinctive characteristic is organization of the abnormal trabeculae into a swirling pattern similar to a fingerprint . Occasionally radiolucent regions resembling cysts may occur in mature lesions of fibrous dysplasia.

40. Effects on surrounding structures. Small lesion: no effect on surrounding structures (subclinical variety). The effects on the involved bone may include expansion with maintenance of a thinned outer cortex . Fibrous dysplasia may expand into the antrum by displacing its cortical boundary and subsequently occupying part or most of the maxillary sinus .

41. Often the bone surrounding the teeth is altered without affecting the dentition. distinct lamina dura disappears.

42. Periodontal ligament space become very narrow. Fibrous dysplasia can displace teeth or interfere with normal eruption, complicating orthodontic therapy. In rare cases, some root resorption may occur. Fibrous dysplasia appears to be unique in its ability to displace the inferior alveolar nerve canal in a superior direction .

43. HISTOPATHOLOGIC FEATURES OF FIBROUS DYSPLASIA No distinguishing histological features between the three types of fibrous dysplasia. Vary with the duration of disease and stage of development. Fd replaces normal bone with a cellular, fibrous tissue containing irregularly shaped bony trabeculae . The trabeculae consist of immature, non lamellar (woven) bone without osteoid rims or osteoblasts .

44. Early lesion → characterized by a fibroblastic tissue which is richly cellular, often revealing a whorled pattern with little bone. "Chinese character trabeculae ". Affected bone usually fuses with the adjacent non-affected bone, whether cortical or cancellous . As FD progresses, the amount of lamellar trabeculae increases. These trabeculae are slender and tend to run parallel to each other. They lie very close together in a moderately cellular fibrous stroma . The term osseous keloid has sometimes been used for this type of lesion.

45. Laboratory findings Serum alkaline phosphatase (ALP) is occasionally elevated, But calcium, phosphorus, parathyroid hormone, in most cases of FD are normal.

46. Differential Diagnosis 1.Hyperparathyroidism 2.Ossifying fibroma 3.Periapical cemental dysplasia 4.Paget’s disease 5.Diffuse sclerosing osteomyelitis 6.Osteosarcoma

47. Malignant Transformation Rare 0.5% (in monostotic disease) to 4% in albright's syndrome . Most common of the malignancies → osteosarcoma , followed by fibrosarcoma and chondrosarcoma . Most malignant neoplasms develop in patients who previously have undergone radiation therapy to the affected area .

48. Treatment and Prognosis Smaller lesions → surgically resected in their entirety without too much difficulty, Large lesions → COSMETIC DEFORMITY → SURGICAL RECONTOURING 25% and 50% of patients show some re-growth after surgical shave-down. Surgical intervention should be delayed for as long as possible. Radiation therapy is contraindicated in fd because it carries the risk for development of post irradiation bone sarcoma

49. cementifying fibroma , cemento -ossifying fibroma,fibrous osteoma benign bone neoplasm According to the 1992 world health organization (who)classification, COF is a "demarcated or rarely encapsulated neoplasm consisting of fibrous tissue containing varying amounts of mineralized material resembling bone and/or cementum .“ WHO (2005) edition of the classification of odontogenic neoplasms has replaced the term COF with OF Ossifying Fibroma (OF)

50. OF is further divided into SUBTYPES: Conventional and Juvenile (JOF) : trabecular (JTOF) Psammomatoid (JPOF)

51. CLINICAL FEATURES AGE: 3 rd and 4 th decades → mean age of 32 yrs SEX: female predilection SITE : mandible(90%) ˃maxilla. Mainly arises in the tooth bearing areas. Most common sites : mandibular premolar and molar areas . Asymptomatic and expansile lesion Pain and paresthesia are rarely associated. Small lesions → detected only on radiographic examination. Larger tumors → painless swelling of the involved bone → facial asymmetry. Growth rate is unpredictable and may be slow and steady or rapid

52. RADIOGRAPHIC FEATURES Eversole et al found 2 MAJOR PATTERNS Well-defined unilocular , round, or oval structures. Larger tumors → multilocular radiographic appearance. According to MacDonald- jankowski initial radiolucent Progressively radiopaque Individual radiopacities coalesce Sclerotic

53. Feature in distinguishing OF from FD: COF is a sharply demarcated lesion. The hard tissues of the tumor do not fuse with the surrounding bone , except occasionally in limited areas Pattern of mineralization varies from place to place within the lesion , whereas in fibrous dysplasia, the pattern tends to be uniform throughout the lesion. A soft tissue capsule at the periphery not seen in fd

54. DIFFERENTIAL DIAGNOSIS Fibrous dysplasia Focal cemento -osseous dysplasia Osteoblastoma Cementoblastoma

55. TREATMENT AND PROGNOSIS Uncomplicated jaw cases → simple enucleation /curettage. Aggressive lesions → more extensive surgical resection. Prognosis → very good Recurrence →rarely encountered

56.   JUVENILE OSSIFYING FIBROMA (Active ossifying fibroma or Aggressive ossifying fibroma ) Johnson et al, in 1952 coined the term juvenile active OF → “cellular mass which generates innumerable small uniform-sized osteoid bodies.” An aggressive variants Usually no fibrous capsule can be demonstrated, Well demarcated from the surrounding bone. 2 patterns: Psammomatoid and Trabecular - juvenile ossifying fibroma

57. etiology Overproduction of the myxofibrous cellular stroma These stromal cells secrete hyaline material that ossifies and connective tissue mucin that initiates the cystic areas ( sarode , sarode et al. 2011).

58. Clinical features Psammomatoid juvenile ossifying fibroma (PJOF) Mean age : 22 years Sex: male˃ female Site: 75% → develop in the orbit, paranasal sinuses and calvaria whereas only about 25% of all cases involve the maxilla or mandible. Maxillary predominance.

59. Trabecular juvenile ossifying fibroma (TJOF) Age : mean age; 11 years Sex: male˃ female. Site: 95% within the jaw bones. Maxillary predominance. In most instances, the neoplasms grow slowly, are well ­circumscribed and lack continuity with the adjacent normal bone

60. Complications With persistent growth, lesions arising in the paranasal sinuses penetrate the orbital, nasal and cranial cavities. Nasal obstruction, Exophthalmos , . Intracranial extension → meningitis

61. RADIOGRAPHIC FEATURES Both tumors →`well-demarcated, unilocular or multilocular radiolucencies with a variable amount of radiopacity . Well Circumscribed radiolucencies . A wispy (similar to stretched tufts of cotton) or flocculent pattern (similar to large, heavy snowflakes) Maxillary tumors → often fill and obliterate the maxillary sinus, Mandibular tumors → usually involve the ramus and angle.

62. TREATMENT AND PROGNOSIS Smaller lesions → complete local excision or thorough curettage. Rapidly growing lesions → wider resection may be required. Recurrence rates → 30% to 58% Malignant transformation has not been documented.

63. CEMENTO- OSSEOUS DYSPLASIA Cemento -osseous dysplasia (COD) are benign fols of the jaws closely associated with the apices of teeth and containing amorphous spherical calcifications which makes them resemble an aberrant form of cementum . In cod, the term dysplasia refers to the abnormal development and disordered production of bone and cementum -like tissue. Most common fibro-osseous lesion encountered in clinical practice . All of the cemento -osseous dysplasias occur in tooth-bearing areas.

64. Cemento -osseous dysplasia can be classified into 2 groups: Non hereditary Periapical Focal Florid Hereditary Familial gigantiform cementoma .

65. ETIOLOGY The etiology and pathogenesis of COD are unknown. Periodontal ligament origin. Extraligamentary bone remodeling may be triggered by local factors and possibly correlated to an underlying hormonal imbalance. Numerous authers : reactive in nature.

66. PERIAPICAL CEMENTO-OSSEOUS DYSPLASIA (Synonyms: Osseous dysplasia, Cemental dysplasia, Cementoma , periapical osteofibroma , periapical fibrous dysplasia) Periapical cemental dysplasia (PCD) is a localized change in normal bone metabolism that results in the replacemeqt of the components of normal cancellous bone with fibrous tissue and cementum -like material, abnormal bone (similar to that seen in fibrous dysplasia) , or a mixture of the two.

67. Solitary or multiple. Marked predilection for female patients (ranging from 10:1 to 14:1 ) Approximately 70% of cases affect blacks. Age: 30 and 50 years. Site: mandibular periapical area is the most common site of appearance.

68. The key points for this disease diagnosis, according to brannon & fowler are : Predilection for mid-age black women ; One or more circumscribed lesions → periapical area of vital teeth; Painless non-expansive lesion located usually at mandible’s anterior area ; Radiographic characteristics can be radiolucency of mixed density (radiolucent with opacities), or opaque with a narrow radiolucent margin; Cellular fibrous stroma with lamellar osseous tissue and/or oval calcifications.

69. Radiographic Features Location. The epicenter-apex of a tooth. Predilection for the Periapical bone of the mandibular anterior Periphery and shape . Well defined. Radiolucent border of varying width is present, surrounded by a band of sclerotic bone that also can vary in width.

70. Internal structure . The internal structure varies, depending on the maturity of the lesion. Effects on surrounding structures . Lamina dura -lost Occasionally hypercementosis occurs. Some lesions stimulate a sclerotic bone reaction from the surrounding bone. Larger lesions may cause expansion of the jaw, an area that is always bordered by a thin, intact outer cortex similar to that seen in fibrous dysplasia.

71. DIFFERENTIAL DIAGNOSOS Pulpoperiapical r/l Traumatic bone cyst Focal cod Cof Cementoblastoma P/a rarefying osteitis

72. Focal cemento - osseous dysplasia Exhibits single site of involvement. According to waldron "localized fibro-osseous cemental lesions presumably reactive in nature.” Sex: 90% in females having male : female of 1: 8, whites > blacks AGE: third to sixth decades ,mean age of 38 years SITE: tooth-bearing areas of the posterior jaws( Previous extractions site) Average size of 1.5 cm Asymptomatic, painless and frequently nonexpansile .

73. FLORID CEMENTO-OSSEOUS DYSPLASIA (FCOD) Multifocal involvement not limited to the anterior mandible. Predominantly involves black women Marked predilection for middle aged to the elderly.(>45yrs) Marked tendency for bilateral and often quite symmetric involvement. Most common in the mandibular molar/premolar region Usually asymptomatic, Sometimes alveolar sinus may be present .

74. DIFFERENTIAL DIAGNOSOS Focal sclerosing osteomyelitis Ossifying fibroma

75. TREATMENT AND PROGNOSIS Asymptomatic patient → regular recall examinations with prophylaxis. Biopsy or elective extraction of teeth should be avoided. Saucerization of dead bone may speed healing.

76. Familial gigantiform cementoma WHO defines it as “A mass of dense, highly calcified partly or almost cellular cementum often occurring simultaneously in a number of different locations in the jaw.” Rare autosomal benign dental tumor Unknown etiopathogenesis

77. CLINICAL FEATURES No sexual predilection COMMON IN african blacks PREVALENCE: first decade; usually ceases during 5 th decade Multi-focal involvement of both the maxilla and mandible → facial deformity Impaction, malposition and malocclusion.

78. “ GINGER ROOT APPEARANCE”

79. TREATMENT Extensive resection of altered bone Facial reconstructive procedures Recurrence is rare

80. CONCLUSION Fibro-osseous lesions are a poorly defined group of lesions affecting the jaws and craniofacial bones. Classification and, therefore, diagnosis of these lesions is difficult because there is significant overlap of clinical and histological features. New terminology has emerged that has culminated in the latest who classification. Definitive diagnosis requires correlation of the histopathologic features with the patient’s history, clinical findings, radiographic/imaging analysis, and operative findings because of the histologic similarities among this diverse group of lesions

81. References Rajendran R, sivapathasundharam B. Shafer’s textbook of oral pathology. 6th edition. Elsevier publication;941-1038 Neville et al. Oral & maxillofacial pathology. 2nd edition. Elsevier publication. Fibro-osseous lesions of the jaws: an insight,” int j contemp dent med rev , vol.2014, article ID 071214, 2014. Benign fibro-osseous lesions of the craniofacial complex -A review Roy Eversole Æ Lan Su Æ Samir ElMofty .head and neck pathol (2008) 2:177–202 5. Mervyn shear. Cysts of the oral and maxillofacial regions. 4 TH edition. Dent clin n am 60 (2016) 167–193 International journal of contemporary dental and medical reviews (2014), article ID 071214, 5 pages