Fibro osseous lesions

definitions, lesions in detail

1. FIBRO-OSSEOUS LESIONS DR. Ratna . Samudrawar III YEAR PG DEPARTMENT OF ORAL MEDICINE & RADIOLOGY RCDSR, BHILAI

2. CONTENTS: Introduction Definitions Classifications Fibrous dysplasia Cherubism Ossifying fibroma Juvenile ossifying fibroma Cemento -osseous dysplasia Central giant cell granuloma Aneurysmal bone cyst Radiological differential diagnosis of fibroosseous lesions Conclusion references

3. INTRODUCTION: All fibro-osseous lesions are characterized by replacement of normal bone by fibrous tissue containing a newly formed mineralized product. The designation fibro-osseous lesion is not a specific diagnosis and describes only a process. Fibro-osseous lesions of the jaws include developmental ( hamartomatous ) lesions, reactive or dysplastic processes, and neoplasms . From a clinical stand point, the fibro-osseous lesions may vary from the extensive, and cosmetically or functionally disturbing lesions detected only during a routine radiographic examination.

4. DEFINITION: Waldron in 1970 described fibro osseous lesions as a group of pathological changes with in the jaw bones in which normal bone is replaced by fibrous tissue ,with or with out calcification . Fibro osseous lesions are a group of conditions that replace normal bone with benign fibrous tissue containing variable amount of mineralization.

5. Fibro – osseous lesion may be non neoplastic or neoplastic & of odontogenic or non odontogenic origin. Regardless of the subtype, all fibro-osseous lesions demonstrate replacement of normal bone by fibrous connective tissue with an admixture of the mineralized product including osteoid , mature bone, and/or cementum like calcifications.

6. Classification : Charles Waldron Classification Of The Fibro-Osseous Lesions Of The Jaws (1985) 1. Fibrous Dysplasia a. Monostotic b. Polyostotic 2. Fibro-Osseous ( Cemental ) Lesions Presumably Arising In The Periodontal Ligament a. Periapical Cemental Dysplasia b. Localized Fibro-Osseous- Cemental Lesions (Probably Reactive In Nature) c. Florid Cement-Osseous Dysplasia ( Gigantiform Cementoma ) d. Ossifying & Cemenifying Fibroma

7. 3. Fibro-Osseous Neoplasms Of Uncertain Or Detectable Relationship To Those Arising In The Periodontal Ligament (Category II) a. Cemetoblastoma, Osteoblastoma & Osteoid Osteoma b. Juvenile Active Ossifying Fibroma & Other So Called Aggressive, Active Ossifying / Cementifying Fibromas .

8. Working Classification Of Fibro-Osseous Lesions By Mico M. Malek (1987) In 1987 from the viewpoint of diagnostic pathologist, a working classification of fibro-osseous lesions was given by Mico M. Malek which is as follows 1. Developmental Disorders A. Fibrous Cortical Defects (Non Ossifying Fibroma ) B. Fibrous Dysplasia 2. Reactive Reparative Lesions A. Traumatic Periosteitis B. Periosteitis Ossificans C. Osseous Keloid D. Periapical Cemental Dysplasia & Florid Cemento -Osseous Dysplasia E. Sclerosing Osteomyelitis (Focal & Diffuse Type) F. Osteitis Deformans

9. 3. Fibromatosis A. Desmoplastic Fibroma ( Intraosseous Fibromatosis ) 4. Neoplasms A. Tooth Bearing Areas Only i . Cementoblastoma ii. Periodontoma 1. Central 2. Peripheral B. All Cranio -Facial Bones (Including Tooth Bearing Areas) i . Osteoma 1. Trabecular 2. Compact ii. Osteoid Osteoma iii. Psammous Desmo-Osteoblastoma iv. Trabecular Desmo-Osteoblastoma

10. Peiter J. Slootweg & Hellmuth Muller (1990) In 1990 Peiter . J. Slootweg & Hellmuth Muller gave a classification that laid emphasis primarily on the histopathological features , and they underscore that this classification requires inclusion of adjacent normal bone to make diagnosis. However in the absence of this, the clinical & radiological features have to be taken in to consideration. Group I: Fibrous Dysplasia Group II: Juvenile Ossifying Fibroma Group III: Ossifying Fibroma Group IV: Periapical Cemental Dysplasia & Florid Osseous Dysplasia

11. WHO Classification (1992) But the identification of identical cementum like tissues in lesions in extra- gnathic sites suggested that this tissues may be a merely normal variant of bone, and that dental cementum itself is a specialized form of “bundle-bone”. Therefore, in the second edition of the who’s classification in 1992, three of the “ cemental ” lesion were transferred to the “neoplasm and other tumors related to bone “group, leaving the benign cementoblastoma as the sole true neoplasm of dental cementum .

12. This second edition of the WHO Histological Typing of odontogenic tumors in 1992 recognized them as the group of cement-osseous dysplasia which included “florid cement-osseous dysplasia” that form with “ Periapical cemental dysplasia” & “other cemento -osseous dysplasia” 1. Osteogenic Neoplasms A.Cemento -Ossifying Fibroma ( Cementifying Fibroma , Ossifying Fibroma )

13. 2. Non- Neoplastic Bone Lesions a. Fiberous Dysplasia Of Jaws b. Cemento -Osseous Dysplasia I. Periapical Cemental Dysplasia ( Periapical Fiberous Dysplasia), II. Florid Cemento -Osseous Dysplasia ( Gigantiform Cementoma , Familial Multiple Cementomas ) III. Other Cemento -Osseous Dysplasia c. Cherubism (Familial Multilocular Cystic Disease Of The Jaws) d. Central Giant Cell Granuloma e. Aneurismal Bone Cyst f. Solitary Bone Cyst (Traumatic, Simple, Hemorrhagic Bone Cyst)

14. Waldron Modified Classification Of Fibro-Osseous Lesions Of Jaws (1993) Later on, to overcome the demerits of his own classification, Waldron reviewed the subject of benign fibro-osseous lesions of jaws (BFOL) in 1993 and suggested a modification of his earlier classification. 1. Fibrous Dysplasia 2. Cement-Osseous Dysplasia a. Periapical Cement-Osseous Dysplasia b. Focal Cement-Osseous Dysplasia c. Florid Cement-Osseous Dysplasia 3. Fibro-Osseous Neoplasm a. Cementifying Fibroma , Ossifying Fibroma , Cement-Ossifying Fibroma

15. Brannon & Fowler Classification (2001) In 2001, Brannon & Fowler gave another classification which was quite different from that of Waldron & WHO classification. this was done to include more number of lesions which were also showing features like FOL: 1. Osseous Dysplasia (OD) (Reactive) a. Nonhereditary i . Periapical ii. Focal iii. Florid b. Hereditary (Developmental) i . Familial Gigantiform Cementoma 2. Fibro-Osseous Neoplasm a. Ossifying Fibroma (OF) b. “Juvenile”, “Active” or “ Aggresive ” Varients of OF

16. 3. Fibrous Dysplasia a. Polyostotic FD b. Monostotic FD c. Craniofacial FD 4. Giant Cell Lesions a. Central Giant Cell Granuloma b. Aneurismal Bone Cyst c. Cherubism 5. Miscellaneous Benign Fibro-Osseous Lesions a. Cementoblastoma b. Tori / Exostoses c. Osteoma

17. WHO Classification Of Fibro-Osseous Lesions Of Jaws (2005) In the latest WHO’s classification of odontogenic tumors in 2005, COD has been therefore called osseous dysplasias (Barnes Et Al.). Because the discussions during these last decades about whether cementum -like tissues is present, it has been decided to give up the term of “cement”. The core of this classification is the concept of a spectrum of clinicopathological entities in which the diagnosis can only be made on the basis of a full consideration of clinical, histological and radiological features. Ossifying Fibroma (OF) 2) Fibrous Dysplasia

18. 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

19. Paul M. Speight & Roman Carlos Classification (2006) In 2006, Paul M. Speight & Roman Carlos gave a classification based on new WHO classification & also from Waldron, Slootweg , Brannon and Fowler and El- Mofty . A number of workers have tried to clarify the classification of these lesions and although that may not have agreed on an exact terminology, a concept has emerged which has culminated in the latest WHO classification. Although the terminology is still problematic, this new classification concentrated on the histopathological features that may guide the working surgical pathologist towards a diagnosis. 1. Fibrous Dysplasia a. Monostotic FD b. Polyostotic FD c. Craniofacial FD

20. 2. Osseous Dysplasia a. Periapical Osseous Dysplasia b. Focal Osseous Dysplasia c. Florid Osseous Dysplasia d. Familial Gigantiform Cementoma 3. Ossifying Fibroma a. Conventional Ossifying Fibroma b. Juvenile Trabecular Ossifying Fibroma c. Juvenile Psammomatoid Ossifying Fibroma

21. Eversole 2008 Classification : Further, a much more comprehensive classification has been suggested by Eversole et al in 2008 and this suggests that the classification of these disease is likely to evolve still further. This classification includes neoplasm, developmental dysplastic lesions and inflammatory/reactive processes. The basis of this classification is that definitive diagnosis can rarely be rendered on the basis of histopathological features alone rather; procurement of a final diagnosis is usually dependent upon assessment of microscopic, clinical and imaging features together. Classification of Benign Fibro-Osseous Lesions of the Craniofacial Complex: 1.Bone dysplasias a. Fibrous dyspla i . Monostotic ii. Polyostotic

22. iii. Polyostotic with endocrinopathy (McCune-Albright) iv Osteofibrous dysplasia b. Osteitis deformans c. Pagetoid heritable bone dysplasias of childhood d. Segmental odontomaxillary dysplasia 2. Cemento -osseous dysplasias a. Focal cemento -osseous dysplasia b. Florid cemento -osseous dysplasia 3.Inflammatory/reactive processes a. Focal sclerosing osteomyelitis b. Diffuse sclerosing osteomyelitis c. Proliferative periostitis

23. 4. Metabolic Disease: hyperparathyroidism 5. Neoplastic lesions (Ossifying fibromas ) a. Ossifying fibroma b. Hyperparathyroidism jaw lesion syndrome c. Juvenile ossifying fibroma i . Trabecular type ii. Psammomatoid type

24. FIBROUS DYSPLASIA (FD): ( ‘fibrocystic disease’, ‘ osteitis fibrosa localisata’,‘focal osteitis fibrosa ’ and ‘fibro- osteodystrophy ’ The term FD was first suggested by Lichtenstein in 1939. FD is a benign fibro-osseous disease frequently affecting the jaw bones and represents about 5% of all benign bone tumors. It is postulated to occur as a result of a developmental failure in the remodeling of primitive bone to mature lamellar bone leaving a mass of immature isolated trabeculae enmeshed in dysplastic fibrous tissue that undergo turn over constantly but never (or very, very slowly) complete the remodeling process. In addition, the immature matrix does not mineralize normally.

25. Pathophysiology : Fibrous dysplasia (FD) is a benign dysplastic disease with a well-known genetic basis. FD is a condition that results from a mutation in (Guanine nucleotide binding protein alpha stimulating activity polypeptide 1 (GNAS 1) gene. The clinical severity of the condition depends upon the time of GNAS 1 mutation occurrence during fetal or postnatal life.

26. If mutation occurs during the early embryonic life , the osteoblast , melanocyte and endocrine cells carry the mutation and express the mutated gene in form of multiple bone lesions, cutaneous pigmentation and endocrine disturbances (McCune Albright syndrome). Mutations in the alpha subunit of a G stimulatory protein lead to constitutive activation of adenylyl cyclase , resulting in a persistent elevation of cyclic adenosine monophosphate ( cAMP ) and stimulation of endocrine receptors.

27. The increase in cAMP as a result of the genetic mutation has several so-called downstream effects . The constitutive elevation in cAMP level caused by Gsα mutations results in abnormal expression of several target genes such as c- fos , c- jun , interleukin-6 (IL-6) which contain cAMP -responsive elements in their promoter which in turn affects. The transcription and expression of several down stream genes and therefore leads to osteoblast recruitment and function disturbance in dysplastic bone lesions.

28. Increased number of osteoclasts and bone resorption observed in fibrous dysplasia have been attributed to IL-6 . In a study accomplished by Candeliere et al., bone marrow spaces of FD-affected bones were shown to contain high levels of c- fos , while healthy subjects bones or uninvolved bones of FD patients showed no c- fos expression. Intracellular c- AMP raises in bone marrow osteo -progenitor cells of FD-affected bones, leading to cell proliferation together with differentiation defects.

29. FD is classified by Waldron as being monostotic when it affects a single bone or, less commonly, polyostotic when it involves multiple bones concomitantly. Two apparently separate types of polyostotic FD are described: FD involving a variable number of bones although most of the skeleton is normal, accompanied by pigmented lesions of the skin or cafe-au- lait spots (Jaffe- lichtenstein type). 2. An even more severe porous dysplasia involving nearly all bones in the skeleton and accompanied by pigmented lesionsof the skin, and in addition, endocrine disturbances of varying types (McCune Albright syndrome).

30. According to shafer’s text book of oral pathology – Apart from the above mentioned types of FD – Craniofacial form and cherubism were also included. C/F FD is diagnosis before the age of 30 years . Equally distributed in both the gender. Monostotic forms at least 6 times more common than polyostotic form.

31. a ) Monostotic FD Monostotic presentation is more frequent, and lesions enlarge in proportion to skeletal growth accounting for 80-85% of cases of FD. This is seen with approximately equal frequency in males and females in their first or second decades of life. It is usually insidious in onset and manifests clinically as a slow growing, painless expansion of the involved bone monostotic FD commonly occurs in the rib (24%), femur (17%), tibia (13%), mandible (12%), and maxilla (12%). In the skull, it commonly involves the ethmoid , sphenoid, frontal, and temporal bones in decreasing order, respectively.

32. The clinical term “ leontiasis ossea ” has often been applied to cases of FD which affects the maxilla or facial bones and give the patient a leonine appearance.

33. Maxillary involvement , specifically posterior maxilla is more common than mandibular .

34. There may be some malalignment , tipping or displacement of the teeth due to the progressive expansile nature of the lesion and tenderness may develop. The mucosa is almost invariably intact over the lesion. Radiological features: The radiographic appearances of FD of jaws is extremely variable Three basic patterns are seen Type 1- the lesion is generally a rather small unilocular radiolucency or a somewhat larger multilocular radiolucency , both with a rather well-circumscribed border and containing a network of fine bony trabeculae .

35. Type one Type two Second type - the pattern is similar except that increased trabeculation renders the lesion more opaque and typically mottled in appearance. Type 1- the lesion is small unilocular radiolucency with well-circumscribed border

36. Type three - peau d’orange ’ / orange peel appearance Third type of quite opaque with many delicate trabeculae gives a ‘ groundglass ’ or ‘ peau d’orange ’ appearance to the lesion.

37. 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, resembling the small fragments of a shattered windshield, a pattern resembling the surface of an orange “ peau d'orange ,

38. Monostotic maxillary fibrous dysplasia, (b) CT showing extensive maxillary involvement, (c) PNS Radiograph showing maxillary sinus obliteration. The CT showed thickening of the frontal and parietal regions with deposition of bone on the inner aspect, at the expense of the cranial contents b-c. The frontal area showed thinning and perforation with loss of the anterior wall of the frontal sinus. Craniofacial fibrous dysplasia: Surgery and literature review, menon .S etal . Annals of maxillofacial surgery. 2013;3(1):66-71

39. (a) An orthopantomogram of case 1 revealing groundglass appearance in the left mandible and having a fusiform shape. (b) A mandibular right lateral cross-sectional occlusal radiograph of case 2 showing ground-glass appearance. (c) An intraoral periapical radiograph of case 2 showing ground-glass appearance and dilacerations of the roots. (d) An orthopantomogram of case 3 revealing ground-glass appearance in the right premolar -- molar region

40. (a) Mandibular right lateral cross-sectional occlusal radiograph of case 10 revealing orange peel appearance. (b) Orthopantomogram of case 10 revealing orange peel appearance with a cystic variety. (c) Orthopantomogram of case 11 revealing cotton wool appearance in the mandible and maxilla involving the craniofacial complex. (d) Mandibular left lateral cross-sectional occlusal radiograph of case 13 showing sunray appearance

41. Orthopantomogram of case 12 revealing sacromatous transformation in the mandible and maxilla involving the craniofacial complex. (b) Axial computed tomography of case 13 showing sun spicule pattern. (c) Maxillary left lateral cross-sectional occlusal radiograph of case 14 revealing thumb print appearance in the molar region

42. Histologic Features: The lesion is essentially a fibrous one made up of proliferating fibroblasts in a compact stroma of interlacing collagen fibers Irregular trabeculae of bone are scattered throughout the lesion with no definite pattern of arrangement. Characteristically, some of these trabeculae are C-shaped/Chinese character-shaped. These trabeculae are usually coarse woven bone but may be lamellar, although not as well organized as normal lamellar bone.

43. POLYOSTOTIC FIBROUS DYSPLASIA Approximately 20–30% of fibrous dysplasias are polyostotic . Polyostotic fibrous dysplasia more frequently involves the skull and facial bones, pelvis, spine, and shoulder girdle. The disease apparently has a distinct tendency to occur in women with a male: female ratio of 1:3 Two-thirds of patients are symptomatic before they are 10 years of age.

44. The sites of involvement are the femur, tibia, pelvis, ribs, skull and facial bones, upper extremities, lumbar spine, clavicle, and cervical spine in decreasing order of frequency. The dysplasia may be unilateral or bilateral

45. Although the polyostotic variety tends to occur in a unilateral distribution, involvement is asymmetric and generalized when disease is bilateral The initial symptom is pain in the involved limb associated with a limp(stiff), spontaneous fracture, or both. In one series, pathologic fracture was present in 85% of polyostotic fibrous dysplasias .

46. Leg-length discrepancy of varying degrees occurs in about 70% of patients due to involvement of upper portion of femur - Hockey-stick deformity The structural integrity of the bone is weakened, and the weight-bearing bones become bowed. The curvature of the femoral neck and proximal shaft of the femur markedly increase causing a Shepherd’s crook deformity, which is a characteristic sign of the disease

47. Philip (1997) polyostotic type of FD is divided in to three subtypes: Craniofacial FD – in which only the bones of craniofacial complex are affected including the mandible and maxilla. Lichtenstein and jaffe type of FD – in which multiple bones of the skeleton with café au lait pigmentation. Albright syndrome type of FD – has a traid of severe polyostotic FD, café au lait pigmentation and various endocrinopathies .

48. Craniofacial form. This pattern of the disease occurs in 10– 25% of patients with the monostotic form and in 50% with the polyostotic form . It also occurs in an isolated craniofacial form. In the isolated variety, no extracranial lesions are present . Sites of involvement most commonly include the frontal, sphenoid, maxillary, and ethmoidal bones. The occipital and temporal bones are less commonly affected.

49. Hyper telorism , cranial asymmetry, facial deformity, visual impairment, exophthalmos , and blindness may occurbecause of involvement of orbital and periorbital bones. Involvement of the sphenoid wing and temporal bones may result in vestibular dysfunction, tinnitus, and hearing loss. When the cribriform plate is involved, hyposmia (reduced ability to smell) or anosmia may result.

50. CT images of fibrous dysplasia. A. Coronal section shows craniofacial type of fibrous dysplasia with involvement 1. frontal, temporal, 2. zygomatic , 3. maxilla, and 4. mandible. B. Another coronal section shows maxillofacial type with involvement of 1. maxilla and 2. zygomatic bone

51. Lichtenstein and jaffe type of FD: In which multiple bones of the skeleton with café au lait (coffee with milk) pigmentation. The hyperpigmentation tends to be on same side and on the skin overlying the lesions of FD. The hyperpigmented macules are well defined and have irregular borders . The color can be medium to dark brown.

52. McCune-Albright syndrome: McCune-Albright syndrome (MAS) is classically defined by the clinical triad of fibrous dysplasia of bone (FD), café-au- lait skin spots, and precocious puberty (PP). In addition to PP (vaginal bleeding or spotting and development of breast tissue in girls, testicular and penile enlargement and precocious sexual behavior in boys), other hyperfunctioning endocrinopathies may be involved including hyperthyroidism, growth hormone excess, Cushing syndrome, and renal phosphate wasting.

53. Therefore, a more clinically relevant definition of MAS, broader than the original triad of FD + PP + café-au- lait is: MAS = FD + at least one of the typical hyperfunctioning endocrinopathies and/or café-au- lait spots, with almost any combination possible. Epidemiology MAS is a rare disease and reliable data of prevalence are not available (the estimated prevalence ranges between 1/100,000 and 1/1,000,000).

54. Pathophysiology : McCune-Albright syndrome has been shown to be due to a postzygotic activating mutation of the GS alpha gene in the affected tissues. The GS alpha subunit is the component of the G-protein complex, which couples hormone receptors to adenylate cyclase (the intracellular second messenger) in a submembrane site. It then mediates the cellular effects of hormone binding.

55. Clinical Features. Precocious puberty associated with the condition is gonadotrophin -independent. Among the endocrine disturbances described in association with Albright syndrome are: Hyperthyroidism Acromegaly Gonadotrophin —McCune-Albright syndrome Hyperprolactinemia Cushing syndrome Hyperparathyroidism Hypophosphatemic rickets.

56. The pigmented macules or café-au- lait spots are related to increased amounts of melanin in the basal cells of the epidermis. They tend to be arranged in a linear or segmental pattern near the midline of the body , usually overlying the lower lumbar spine, sacrum, buttocks, upper back, neck, and shoulders.

57. Similar lesions may occur on the lips and oral mucosa. Pigmentation may occur at birth , and precede the development of skeletal and endocrine abnormalities.

58. Café-au-lait skin pigmentation. A typical lesion on the face, chest, and arm of a 5-year-old girl with McCune-Albright syndrome which demonstrates jagged " coast of Maine " borders, and the tendency for the lesions to both respect the midline and follow the developmental lines of Blashko .

59. Malignancies in MAS While malignancies associated with MAS are distinctly rare occurrences. This occurs in probably less than 1% of the cases of FD/MAS. While some have suggested that sarcomatous transformation of skeletal lesions may occur more commonly in patients with Mazabraud's syndrome ( benign intramuscular myxomas in association with long standing FD)

60. Radiographic features: In general, lesions in the long bones have a " lytic " appearance . The lesions usually arise in the medullary cavity and expand outward replacing normal bone, which results in thinning of the cortex . It is usually the metaphysis and/or the diaphysis that are involved, with sparing of the epiphysis

61. The appearance of FD may vary from entirely lytic (probably due to cystic degeneration) to entirely sclerotic.  On the left images of a patient with polyostotic fibrous dysplasia, with lucent lesions in the proximal and mid- diaphyseal femur, and lesion with groundglass density and calcifications in the fibula The lesion may be surrounded by a layer of thick, sclerotic reactive bone ( rind sign )

62. Anteroposterior radiograph of the hip of a twenty-two-year-old man who presented with a two-year history of hip pain. The radiograph demonstrates a fatigue fracture of the femoral neck with the characteristic “parrot’s beak” deformity.

63. a wispy arrangement “cotton wool”, or an amorphous, dense pattern Occassionally,organization of the abnormal trabeculae into a swirling pattern similar to a fingerprint

64. DIFFERENT APPEARENCES IN FD (ACC TO HM WORTH) Thumb print appearance: it occurs at the lower margin of the jaw as if, when it was soft the imprint has been made, squashing out a portion of the bone, causing it to protrude. This picture is pathognomic of fibrous dysplasia. Part of a panoramic radiograph showing the ‘‘thumb print’’ pattern of the lesion in the mandible . Note that the inferior dental canal has been displaced inferiorly Fibrous dysplasia—a 13-year retrospective radiographic analysis in a south Indian population. DMFR 2011

65. Over a localized area the cortex is lost and the site there is smooth and curved projection downward of the inferior margin of the bone, the convexity downward. The appearance resembles thumbprint, as if the bone had been soft and pressed upon by the thumb. Ribbon like cortex : when present next to thumb print stamps the diagnosis of FD. Stippled appearance of the bone: pathognomic orange peel appearance:

66. FINGERPRINT PATTERN GROUND GLASS PATTERN COTTON WOOL PATTERN ORANGE PEEL PATERN

67. EFFECTS TO SURROUNDING STRUCTURE: If small- no effect (subclinical variety) Expansion of bone with maintanence of thinned cortex May expand into antrum Bone surrounding the teeth may get affected without affecting the dentition. Lamina dura may get disappear. PDL space become narrow Has unique ability to displace IAN canal to superior direction.

68. OTHER RADIOLOGICAL FEATURES : Cyst like Peau d’ orange Finger print pattern Cotton ball pattern in adult monostotic fibrous dysplasia Sclerotic Smoky & cloudy appearance( Waldron & Giansanti ) Chalky appearance Whorled Diffuse sclerosis ( Obisesan & coworkers)

69. Obisesan et al classified the lesions of fibrous dysplasia radiographically into 6 types. • ‘ Peau d’ orange’ or orange peel— in this type, there are alternating areas of granular density and lucency giving a radiographic appearance resembling the ring of orange. Whorled plaque like type —in this type, the matrix of the well circumscribed lesion is composed of plaques of amorphous material of intermediate radiodensity , which on close examination are seen to be arranged in whorled onion peel appearance. Diffuse sclerotic type —the lesions of this show as homogeneous dense area, which gradually merges with the normal bone.

70. Cyst like type —in this type, the lesions are radiolucent. It is unilocular or multilocular , more often multilocular with well defined margins. Pagetoid type —in this type of lesions, the affected area of bone markedly expands and shows alternating areas of radiopacities and lucency , as those seen in Paget’s disease of bone. Chalky type —it manifests itself as a well circumscribed lesion consisting of an amorphous dense radiopaque material. Text book of oral medicine – anil ghom 2/e

71. RADIOLOGICAL FINDINGS IN CRANIOFACIAL REGION : Cortical plate expansion Tooth root displacement Lamina dura is obscured, because this bone is changed into the abnormal bone pattern. Thinned cortical plates Inferior alveolar canal is displaced superiorly and laterally, which helps to distinguish from ossifying fibroma. Skull lesions – bulging of outer table Typical sclerotic density in the base of the skull.

72. SKULL LESIONS : Wilner has classified into three types- Lytic Mixed (localized, regional, diffuse) Sclerotic. LONG BONES : Femur – Shepherd’s crook or Hockey stick deformity Long bones – Candle flame appearance Iliac lesions – Smudged appearance.

73. BONE SCAN : Technetium diphosphonate – increased uptake of radionuclide. Described as “Hot”. Increased uptake is seen in ground glass & cystic appearing lesions and bowed bones.  COMPUTED TOMOGRAPHY : Shows typical ground glass appearance To assess fluid-fluid levels To assess full thickness cortical destruction.

74. MAGNETIC RESONANCE IMAGING : Best tool to assess intraosseous extent. To define the internal architecture. Typical abnormal dark gray marrow signal of fibrous tissue on T1 weighted images changes on T2 weighted images. On T2 – increase intensity is in cystic areas or fractures & less in calcified area

75. Laboratory investigations: Serum alkaline phosphatase levels  . Serum calcium, phosphate, and vitamin D levels = N Thyroid function tests, including triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) levels, are performed to exclude hyperthyroidism. Pituitary gonadotropins and Sex hormone levels are assessed . There are no consistent significant changes in the serum calcium or phosphorus, although the serum alkaline phosphatase level is sometimes elevated. Premature secretion of pituitary follicle-stimulating hormone has been reported, as well as moderately elevated basal metabolic rate.

76. COMPLICATIONS Fracture Deformity Malignant transformation occurs in fewer than 0.5% - 1% of cases. Formation of aneurysmal bone cysts Osteomyelitits

77. D/D: Ossifying fibroma Neurofibromatosis : Cutaneous pigmentation in polyostotic fibrous dysplasia is ipsilateral to the side of bony lesions, a feature that differentiates this disease from pigmentation in neurofibromatosis. Chronic sclerosing osteomyelitis Pagets disease: serum alkaline phosphate levels are elevated Osteosarcoma : Cortical bone destruction, Invasion into surrounding structures

78. Features Fibrous dysplasia Ossifying fibroma Margins Not demarcated Well demarcated Shape Fusiform Spherical or elongated Cortices Replaced by disease Expanded –present or partially present Medullary pattern Homogenous Heterogenous

79. Management: • Surgical—surgical removal of the lesion should be carried out. Osseous contouring—it is necessary for correcting the deformity for esthetics or pre-esthetic purposes.

80. CHERUBISM (Familial fibrous dysplasia of jaws, disseminated juvenile fibrous dysplasia, familial multilocular cystic disease of jaws, familial fibrous swelling of jaws) First described by Jones in 1933. An autosomal dominant fibro-osseous lesion of the jaws involving more than one quadrant that stabilizes after the growth period, usually leaving some facial deformity and malocclusion. Affects the jaws of children bilaterally and symmetrically, usually producing the cherubic look

81. According to the WHO classification, cherubism belongs to a group of non- neoplastic bone lesions affecting only the jaws. It is a rare, benign condition with autosomal dominant inheritance. Lesion remits after puberty. Genetic basis – The locus for the cherubism gene in 4p16 . Ueki etal detected point muations causing amino acid substitutions in the SH3-binding protein SH3BP2.

82. C/F Affected children are normal at birth and are without clinically or radiographically evident disease until 14 months to 3 years of age. At that time, symmetric enlargement of the jaws begins. Typically, the earlier the lesion appears, the more rapidly it progresses

83. The self-limited bone growth usually begins to slow down when the patient reaches five years of age, and stops by the age of 12–15 years. Respiratory obstruction and impairment of vision and hearing. The lesions, which are firm to palpation and nontender , most commonly involve the molar to coronoid regions, the condyles always being spared , and are often associated with cervicaL lymphadenopathy Profound swelling of maxilla, may results in streching of skin of cheeks, which depresses the lower eyelids giving ‘eye raised to heaven apperance ’

84. Oral manifestations: When maxilla is involved, the palate assumes V shape. Agenesis of the second and third molars of the mandible, displacement of the teeth, premature exfoliation of the primary teeth, delayed eruption of the permanent teeth, and transpositions and rotation of the teeth. In severe cases, tooth resorption occurs. In few cases cherubism has been described as being associated with other diseases and conditions such as Noonan’s syndrome, gingival fibromatosis , psychomotor retardation, and obstructive sleep apnea

85. . Facial appearance of the patient showing symmetrical swelling of the mandibular angles. B , Intraoral image showing thickening of the alveolar processes, with partial obliteration of the palatal vault Peñarrocha et al. Cherubism . J Oral Maxillofac Surg 2006.

86. Arnott’s grading system grade I: by involvement of both mandibular ascending rami , grade II: involvement of both maxillary tuberosities as well as the mandibular ascending rami , and grade III : McCune- Albright syndrome involvement of the whole maxilla and mandible except the coronoid process and condyles .

87. In order to over come the limitations of arnott’s classification system, kalantar Motamedi developed a different classification system which addresses both the involvement and aggressive behaviour of the disease. Grade- I : lesions of mandible without signs of root resorption . Grade –II: lesions of mandible and maxilla without signs of root resorption .

88. Grade – III : aggressive lesions of mandible with signs of root resorption Grade – IV: lesions involving mandible and maxilla with signs of root resorption . Grade – V : massively growing , aggressive and extensively deforming juvenile cases involving the maxilla and the mandible and which may include the coronoid process and condyles

89. R/F Characterized by bilateral multilocular cystic expansion of the jaws. Early lesions occur in the posterior body of the mandible and the ascending rami . Maxillary lesions may occur at the same time but escape early radiographic detection because of overlap of the sinus and nasal cavities. Displacement of the inferior alveolar canal.

90. The presence of numerous unerupted teeth and the destruction of the alveolar bone may displace the teeth, producing a radiographic appearance referred to as floating tooth syndrome

91. With adulthood, the cystic areas in the jaws become re-ossified, which results in irregular patchy sclerosis. There is a classic (but nonspecific) ground glass appearance because of the small, tightly compressed trabecular pattern. Location. - This lesion is bilateral and often affects both jaws. When it is present in only one jaw, the mandible is the most common location.

92. The epicenter is always in the posterior aspect of the jaws , in the ramus of the mandible, or the tuberosity of the maxilla The lesion grows in an anterior direction and in severe cases can extend almost to the midline. Periphery - The periphery usually is well defined and in some instances corticated.

93. Internal structure. The internal structure resembles that of CGCG, with fine, granular bone and wispy trabeculae forming a prominent multilocular pattern. Effects on surrounding structures. Expansion of the cortical boundaries of the maxilla and mandible by cherubism can result in severe enlargement of the jaws.

94. Maxillary lesions enlarge into the maxillary sinuses. Because the epicenter is in the posterior aspect of the jaws, the teeth are displaced in an anterior direction. The degree of displacement can be severe, and with some lesions the tooth buds are destroyed

95. Histological features: Numerous multinucleated giant cells Various spindle shaped fibroblasts Numerous small vessels are present, and the capillaries exhibit large endothelial cells and perivascular cuffing.

96. D/D Giant cell granuloma of jaws – usually unilateral , affects 20-40 years of age . Osteoclastoma – occurs rarely in jaws unlike cherubism Aneurysmal bone cyst – may also exihibit giant cells but its main feature is a cavity lined with tissue other than endothelium. Fibrous dysplasia- mostly 2 or 3 decade of life. elevated level of serum alkaline phospatasae , histopathology shows chinese characters with proliferating stroma . Hyperparathyroidism- rarely affects jaws. Serum concentration of calcium and PTH can help in distinguishing

97. Treatment : The condition is selflimiting and generally regresses by puberty. Surgery to correct the jaw deformities of cherubism .

98. OSSIFYING FIBROMA ( cementifying fibroma ; cemento -ossifying fibroma ) Introduction : OF is most common fibroosseous neoplasm of the jaw. It is bone producing , slowly growing asymptomatic, well demarcated, bening lesion common in maxilla and mandible. The tumor is defined as demarcated and occasionally capsulated consisting of fibrous tissue containing variable amounts of mineralized material resembling bone or cementum or both.

99. The term OF is used if the predominant component is bone . Cementifying fibroma is used when the predominat component is cementum - like spherical calcifications . The lesions characterised by presence of bone and cementum are refferred as cemento – ossifying fibroma . Etiology – OF occuring in jaws seems to arise from periodontal membrane which contains pluripotential cells capable of forming cementum , bone and fibrous tisssue .

100. C/F There is a definite female predilection . Seen in third and fourth decade of life. OF predominantly affects the craniofacial bone and rarely involves the long bones. Mandible is involved more than maxilla. Mandibular premolar and molar area is the most common site. The lesion appears as hard , localized and slow growing , painless mass that may displace adjacent structures and cause root resorption .

101. R/F The lesion appears to be well defined. Initially lesions are radiolucent representing an osteolytic image followed by gradual transformation into a mixed lesion and eventually becoming radioopaque . The periodontal ligament space of the involved teeth is clearly seen unlike FD. Eversole et al described 2 basic patterns – Unilocular radiolucency with /without radiopaque foci A multilocular radiolucency . The unilocular pattern is more common. Expansion of cortical plates are common finding. Lamina dura of involved teeth usually missing, teeth displacement and root resorption may be seen

102. Well-delimited mixed radiographic image causing displacement of the involved teeth  Ossifying Fibroma of the Jaws: A Clinicopathological Case Series Study, andrade M, Braz. Dent. J. 2013;24(6). OF shows a well-demarcated mixed radiolucent and radiopaque image as observed in all cases from this series, which were well-circumscribed and separated from the cortical bone.

103. H/F It shows fibrous and osseous tissue with former tissue predominating . The fibrous stroma is highly cellular with spindle shaped fibroblastic cells arranged in whorls . Osteoblastic rimming along the trabeculae are seen . The spherules of cementum like material often demonstrates peripheral brush borders that blend into the adjacent connective tissue.

104. D/D In fact,the differential diagnosis depends on the radiographic features of the lesion. In OF, it appears as a radiolucent image , odontogenic cysts, ameloblastoma , central giant cell lesions and idiopathic bone cavity. For mixed lesions , osteoblastoma , calcifying cystic odontogenic tumor and calcifying epithelial odontogenic tumor should be considered in the differential diagnosis. Finally, for radiopaque OF, complex odontoma and idiopathic osteosclerosis are the main differential diagnoses.

105. OF may also resemble a cementoblastoma if it occurs around the tooth root however, cementoblastoma is fused to the tooth root. Management : excision

106. JUVENILE OSSIFYING FIBROMA- (juvenile active ossifying fibroma Or Juvenile aggressive ossifying fibroma ) JOF is an uncommon lesion that affects the jaw of children under 15 years of age. Etiology : JOF is considered to develop from undifferentiated cells of periodontal ligament. Two histologic variants of juvenile ossifying fibroma are : Trabecular psammomatoid

107. C/F: The lesion characteristically occurs under the age of 15 years. The psammomatoid variant occurs exclusively in the extragnathic craniofacial region especially in the orbit bones and paranasal sinuses (61.6%), maxilla (19.7%) and mandible (7%). In mandible ,the tumor occurs more commonly in the ramus than in the body of the mandible No gender predeliction . Patients often present with symptoms such as exopthalmus , bulbar displacement and proptosis when affecting the orbital bones and paranasal sinuses.

108. Development of aneurysmal bone cyst in psammomatoid juvenile ossifying fibroma is commonly reported . Trabecular variant is characterized by a progressive and sometimes rapid aggressive growth. The tumor expands the affected bone, leading to facial asymmetry. It occurs more commonly in maxilla as compared to mandible

109. R/F- The psammomatoid variant shows well defined expansion of affected bone having mixed radolucent , radiodense and ground glass appearance. The lesion is partially or completely surrounded with thin, corrugated margins. Sometime multilocular appearances may be seen representing the small cystic spaces .

110. The trabecular variant is expansive , well defined and unilocular or multilocular with cortical thinning and perforation . The tumor mass is radiolucent with variable calcification induced radiopacities , occasionally demonstrating fine specks and producing ground glass appearance. Increase in radiodensity may be observed over time Root resorption and displacement of involved teeth are also observed.

111. pattern An expansile growth in lower right anterior region with mixed radiolucent and radiopaque Trabecular Juvenile Ossifying Fibroma of the Craniofacial Skeleton: Etiopathogenesis and a Case Report of the Rare Entity,   Kadam.R et al i nternational Scientific Journali 2014;4(1):51-55.

112. H/F Psammomatoid juvenile ossyfing fibroma shows well demarcated but uncapsulated lesion composed of numerous small rounded mineralised collagenase bodies ( psammomatoid ossicles ). Uniformly distributed within a cellular fibroblastic stroma . Occasional shrunken cells , representing neucli of osteocytes , are embedded within the ossicles , there is usually a collagen outer band to these mineralised bodies.

113. Trabacular variant – shows an uncapsulated tumor mass infilterating into the surrounding bone and reactive bone formation at the periphery . The tumors show a characteristic loose structure with cell rich stroma composed of fibroblastic spindle cells that produced little collagen. Anastomosing trabaculae of osteoid is seen in a pattern that resembles pain brush strokes .

114. Aggregates of osteoclastic giant cells are commonly present and seen in association with the bony trabeculae and in separate foci in the fibrous stroma . Management : excision Recurrence reported to a range of 30-50% in both the types. Malignant change has not been reported.

115. CEMENTO-OSSEOUS DYSPLASIA The jaws can be affected by several non- neoplastic cementum -containing lesions. Collectively, these are referred to as cemento -osseous dysplasias . In these cases, the term dysplasias are used to designate abnormal development. All are presumed to be derived from the periodontal ligament.

116. These are classified into: Focal Cemento Osseous Dysplasia Periapical Cemental Dysplasia Florid Cemento Osseous Dysplasia

117. Periapical Cemental Dysplasia Synonyms Cementoma , fibrocementoma , sclerosing cementoma , periapical osteofibrosis , periapical fibrous dysplasia, and periapical fibroosteoma . DEFINITION: Periapical cemental dysplasia (PCD) is a localized change in normal bone metabolism that results in the replacement 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. By definition the lesion is located near the apex of a tooth.

118. Etiopathogenesis Irrespective of the cause, the initial lesion of PCD is thought to occur as a result of a proliferation of the principal fibers of the periodontal ligament in the apical region of a tooth root. Thoma has described three stages in the development of this entity.

119. The first osteolytic stage is characterized by proliferation of the principal fibers of the periodontal ligament, resulting in the destruction and replacement of the contiguous bone by a well- Circumscribed mass of fibrous connective tissue that may or may not contain small, isolated nests of cementum and or bone.

120. In the second cementoblastic stage, larger islands of cementum or bone are deposited within the fibrous stroma. The third mature stage is characterized by fusion of the previously formed nests of cementum or bone, eventuating in the formation of a calcified mass. It has been estimated that this calcification process may take from 1 to 20 years or from 3 to 10 years. In some instances, however, the lesion may remain static or even regress.

121. Clinical features PCD is a common bone dysplasia that typically occurs in middle age; the mean age is 39 years. It occurs nine times more often in females Three times more often in blacks than in whites. The involved teeth are vital, and the patient usually has no history of pain or sensitivity.

122. The lesions usually come to light as an incidental finding during a periapical or panoramic radiographic examination made for other purposes. The lesions can become quite large, causing a notable expansion of the alveolar process, and may continue to enlarge slowly.

123. R/ F Location - The epicenter of a PCD lesion usually lies at the apex of a tooth. In rare cases the epicenter is slightly higher and over the apical third of the root. Radiolucent Stage. Two periapical films showing loss of lamina dura ; however, the periodontal membrane space can still be seen around some of the teeth.

124. Predilection for the periapical bone of the mandibular anterior teeth, although any tooth can be involved, and in rare cases the maxillary teeth may be involved. Examples of periapical cemental dysplasia in the maxilla. A mixed lesion. B Mature lesions

125. In most cases the lesion is multiple and bilateral, but occasionally a solitary lesion arises. If the involved teeth have been extracted, this lesion can still develop but the periapical location is less evident . In these cases the term cemental dysplasia may be more appropriate.

126. Periphery and shape . In most cases the periphery of a PCD lesion is well defined. Often a radiolucent border of varying width is present, surrounded by a band of sclerotic bone that also can vary in width.

127. The sclerotic bone represents a reaction of the immediate surrounding bone. The lesion may be irregularly shaped or may have an overall round or oval shape centered over the apex of the tooth. Internal Structure . The internal structure varies, depending on the maturity of the lesion. In the early stage, normal bone is resorbed and replaced with fibrous tissue that usually is continuous with the periodontal ligament ( causing loss of the lamina dura ). Radiographically , this appears as a radiolucency at the apex of the involved tooth

128. In the mixed stage , radiopaque tissue appears in the radiolucent structure. This material usually is amorphous; has a round, oval, or irregular shape; and is composed of cementum or abnormal bone

129. Sometimes the cementum -like material forms a swirling pattern. These structures sometimes are called cementicles .

130. In the mature stage, the internal aspect may be totally radiopaque without any obvious pattern. Usually, a thin radiolucent margin can be seen at the periphery because this lesion matures from the center outward.

131. Effects on surrounding structures . The normal lamina dura of the teeth involved with the lesion is lost, making the periodontal ligament space either less apparent or giving it a wider appearance.

132. The tooth structure usually is not affected, although in rare cases some root resorption may occur. Also, occasionally hypercementosis occurs on the root of a tooth positioned within the lesion. Some lesions stimulate a sclerotic bone reaction from the surrounding bone. Small lesions do not cause expansion of the involved jaw. However, 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. This lesion may elevate the .floor of the maxillary antrum .

133. Differential diagnosis Periapical rarefying osteitis : PCD cannot be differentiated from inflammatory lesions in the early stage by radiographs alone. Final diagnosis rely on clinical examination and final diagnosis. Benign cememtoblastoma In the case of a solitary mature form of PCD, the differential diagnosis may include a benign cementoblastoma , especially when the lesion is periapical to the mandibular first molar

134. This tumor is usually is attached to the surface of the root, which may be partly resorbed . Also, the peripheral soft tissue capsule is better defined and there may be a unique pattern to the internal structure, such as a radiating pattern. The presence or absence of clinical symptoms may help distinguish PCD from benign cementoblastoma .

135. BENIGN CEMENTOBLASTOMA PCOD

136. FOCAL CEMENTOOSSEOUS DYSPLASIA It is a recently described entity that is thought to fall between P.C.D. and florid osseous dysplasia in the biologic spectrum of C.O.D. The term focal cementoosseous dysplasia was first suggested by Tomich and Summerline in 1989. The etiology and precise pathogenesis are unknown, but it is thought to be a reactive lesion. Clinical features: (1) Most common in females and a higher incidence in whites.

137. Seen in 4 th to 5 th decades of life Seen in edentulous areas Lesions are typically solitary involving the bone in posterior mandible. Characteristically asymptomatic and frequently discovered during routine radiographic examination.

138. R/F Most lesions are mixed radiolucent – radio opaque areas, although the radiographic appearance may very from well defined radiolucent lesion to a densely radio opaque area. Most of lesions < 1.5 cm in size H/F Microscopically areas of cellular fibrous tissue containing numerous small blood vessels, irregular trabaculae of woven bone or cemetum like calcifications are seen .Scattered foci of multinucleate giant cells may seen.

139. Focal cementoosseous dysplasia masquerading as a residual cyst. Bhandari .R Contemp Clin Dent. 2012 ; 3: S60–S62.

140. D/D PCD FCOD frequently occurs in edentulous as well as dentulous areas, whereas PCD is always found apically to teeth Treatment and prognosis: As lesions exhibits only limited potential for progressive growth, most lesions require no additional treatment. Partial removal of the lesion also advocated in cases. .

141. FLORID CEMENTO-OSSEOUS DYSPLASIA Synonyms Florid cemento -osseous dysplasia, gigantiform cementoma , familial multiple cementomas , sclerotic cemental masses, sclerosing osteitis . Florid osseous dysplasia (FOD) is a widespread form of PCD. The term Florid cemento osseous dysplasia was first suggested by Melrose et al in 1976. Normal cancellous bone is replaced with dense acellular cemento -osseous tissue in a background of fibrous connective tissue.

142. Etiology - is unknown Waldron has proposed reactive or dysplastic changes in periodontal ligament may be a cause The lesion has a poor vascular supply, a condition that likely contributes to its susceptibility to infection. In some cases a familial trend can be seen.

143. C/F Most patients with FOD are female (blacks) and middle aged Striking tendency for bilateral occurance often presenting symmetry of the jaws. Many patients are partially or completely edentulous when the conditions are detected. Occasionally patients complain of low-grade, intermittent, poorly localized pain in the affected bone, especially when a simple bone cyst has developed within the lesion.

144. Extensive lesions often have an associated bony swelling. If the lesions become secondarily infected, features of osteomyelitis may develop, including mucosal ulceration, fistulous tracts with suppuration, and pain.

145. R/F Location. FOD lesions usually are bilateral and present in both jaws). However, when they are present in only one jaw, the mandible is the more common location. The epicenter is apical to the teeth, within the alveolar process and usually posterior to the cuspid . In the mandible, lesions occur above the inferior alveolar canal .

146. Periphery. The periphery usually is well defined and has a sclerotic border that can vary in width, very similar to PCD. Soft tissue capsule may not be present in mature lesions.

147. Internal Structure. The density of the internal structure can vary from an equal mixture of radiolucent and radiopaque regions to almost complete radiopacity . Some prominent radiolucent regions, which usually represent the development of a simple bone cyst, may be present. These cysts may enlarge with time, even beyond the boundary of the lesion into the surrounding normal bone, or may fill in with abnormal dysplastic cemento -osseous tissue.

148. The radiopaque regions can vary from small oval and circular regions (cotton-wool appearance) to large, irregular, amorphous areas of calcification. These calcified masses are similar in appearance to those seen in mature PCD lesions.

149. Two examples of florid osseous dysplasia (FOD) associated with multiple simple bone cysts.

150. Effect on the sourrounding structure Large lesions may displace inferior alveolar nerve canal Floor of antrum in superior direction Expansion of cortices Hypercementosis irt involved tooth, which may fuse with the adjacent teeth (extraction difficult) Histopathological features: FCOD shows admixtures of woven bone trabaculae and droplets of cementum like calcifications in a fibroblastic stroma . The cementum like calcifications often fuse to form coalescing masses.

151. D/D PAGET’S DISEASE: PD also shows cotton wool appearance and hypercmentosis , but PD affects entire bone whereas FOD is centered above the inferior alveolar nerve canal. Also PD is polystotic .

152. Paget' Disease (PD) Florid Cemento -Osseous Dysplasia (FLCOD) Generalized changes that are apparent throughout the jaws Alterations confined to tooth-bearing areas. Maxilla preferentially affected Mandible is favored. May cause displacement and separation of teeth. No effect on tooth alignments More common in females More Common males Accompanied by increase in serum alkaline phosphatase levels. Alkaline phosphatase levels are within normal limits Often polyostotic and frequently involves the skull. Disease limited to the jaw.

153. Chronic diffuse sclerosing osteomyelitis Regions of cementum -like masses may appear similar to the sequestrum seen in osteomyelitis . This is not to be confused with a situation where FOD has become secondarily infected, resulting in osteomyelitis . The cemental -like masses that are secondarily infected have a wider and more profound radiolucent border CT imaging is essential for the diagnosis and to determine the extent of the osteomyelitis within the FOD.

154. A, Axial CT of a case of florid osseous dysplasia (FOD); multiple foci of cemental dysplasia are bordered by a soft tissue capsule (white arrow) and a cemental mass has become secondarily infected with a wider and more pronounced radiolucent border (black arrow). B, Axial CT image of a different casae of osteomyelitis from secondarily infected FOD; note the break in the outer cortex where the lesion is draining into the surrounding soft

155. CENTRAL GIANT CELL GRANULOMA Synonyms Giant cell reparative granuloma , giant cell lesion, and giant cell tumor Central giant cell granuloma (CGCG) is thought to be a reactive lesion to an as-yet-unknown stimulus and not a neoplastic lesion. C/F CGCG is a common lesion in the jaws that affects mostly adolescents and young adults; at least 60% of cases occur in individuals younger than 20 years.

156. The most common presenting sign of CGCG is painless swelling. The overlying mucosa may have a purple color. Some of these lesions cause no symptoms and are found only on routine examination. The lesion usually grows slowly, although it may grow rapidly, creating the suspicion of a malignancy.

157. Depending on clinical and radiographic features, central giant cell granuloma can be classified into two types. The first type of lesion is non-aggressive, slow growing, does not show root resorption or cortical perforation, and often shows new bone formation. The second type is an aggressive type which grows quickly, shows pain, cortical perforation, and root resorption .

158. R/F Location- Lesions develop in the mandible twice as often as in the maxilla. In the first two decades there is a tendency for the epicenter of the lesion to be anterior to the first molar in the mandible and anterior to the cuspid in the maxilla. However, in older individuals this lesion can occur in greater frequency in the posterior aspect of the jaws

159. Periphery.- Because this grows relatively slowly, it usually produces a well-defined radiographic margin in the mandible. In most cases the periphery shows no evidence of cortication. Lesions in the maxilla may have ill-defined, almost malignant-appearing borders.

160. Internal Structure. Some CGCG lesions show no evidence of internal structure, especially small lesions. Other cases have a subtle granular pattern of calcification. granular bone is organized into ill-defined, wispy septa If present, these granular septa are characteristic of this lesion. especially if they emanate at right angles from the periphery of the lesion. In some instances the septa are better defined and divide the internal aspect into compartments, creating a multilocular appearance.

161. Effects on Surrounding Structures. Giant cell granulomas often displace and resorb teeth with irregular outline. The lamina dura of teeth within the lesion usually is missing. The inferior alveolar canal may be displaced in an inferior direction. This lesion has a strong propensity to expand the cortical boundaries of the mandible and maxilla.

162. Histologic Features. Central giant cell granuloma is made up of a loose fibrillar connective tissue stroma with many interspersed proliferating fibroblasts and small capillaries. The collagen fibers are not usually collected into bundles; however, groups of fibers will often present a whorled appearance. Multinucleated giant cells are prominent throughout the connective tissue , but not necessarily abundant.

163. In addition, there are usually numerous foci of old extravasated blood and associated hemosiderin pigment , some of it phagocytized by macrophages. Foci of new trabeculae of osteoid or bone also are often seen, particularly around the periphery of the lesion.

164. Treatment and Prognosis. The treatment of the giant cell granuloma is curettage or surgical excision. The lesions so treated almost invariably fill in with new bone and heal with no difficulty. Occasional lesions recur, but this is seldom sufficient cause for more radical procedures. X-ray radiation is contraindicated.

165. Interim intralesional steroids definitely helped to prevent the progression of this lesion and avoided extensive bony destruction.( MOA-It has been shown that osteoclast -like multinucleated giant cells decrease their lysosomal protease extracellular production, which mediates bone resorption , in the presence of steroids. An Unusual Presentation of a Central Giant Cell Granuloma and Initial Treatment with Intralesional Steroids– A Case Report and Review of the Literature. Richard M Graham et alJ Oral Health Comm Dent 2008;2(3):65-69

166. Successful examples of the use of intralesional steroids are as follows: In Kurtz’s case; 12 injections of intralesional Triamcinalone Acetonide were given, in total, for a 15cm lesion, 150mg each for at least 6 of these, which resulted in complete re-ossification of the area affected by a central giant cell granulomas . In addition, Carlos et al. have reported 4 cases of central giant cell granulomas , which were treated successfully in the same way (the average dose was 25mg of Triamcinalone Acetonide for the paediatric patients). Khafif et al.’s case of a central giant cell granuloma of the maxilla was successfully treated with intralesional corticosteroids; there was no lesion recurrence and the defect calcified (average dose of 40mg Triamcinalone Acetonide + 0.5% Bupivacaine weekly for 6 weeks).

167. Aneurysmal Bone Cyst Aneurysmal bone cyst (ABC) has been recognized since 1893 when it was described as an ossifying hematoma by Van Arsdale . An aneurysmal bone cyst (ABC) usually is considered to be a reactive lesion of bone rather than a cyst or true neoplasm. It represent an exaggerated proliferative response of vascular tissue in bone.

168. The cause of this strange process in bone is unknown but several examples apparently arose after a fracture. It is similar to and probably related to other reactive non- neoplastic processes, including giant cell reparative granuloma of the jaws, traumatic reactions in periosteum and bone and even florid heterotopic ossification. Aneurysmal bone cyst may arise denovo in bone; that is, a definite preexisting lesion cannot be demonstrated in the tissue. Rarely malignant tumors of bone contain such benign areas as well. Obviously, recognition of an underlying process is important.

169. C/F Fifty percent of ABCs arise in the long bones and 20% in the vertebral column. It accounts for 1.5% of the nonodontogenic , nonepithelial cysts of the mandible Younger than 30 years. predilection for females. It is found more frequently in the mandible than the maxilla (3:1) with preponderance for the body, ramus and angle of the mandible. An ABC in the jaw usually manifests as a fairly rapid bony swelling . Pain is an occasional complaint, and the involved area may be tender on palpation

170. R/F Location - The mandible is involved more often than the maxilla (ratio of 3 : 2), and the molar and ramus regions are more involved than the anterior region Periphery and Shape. The periphery usually is well defined, and the shape is circular or “ hydraulic. ” Aneurysmal bone cyst of the mandible: A case report and review of literature, parvathi devi J Oral Maxillofac Pathol ; 15(1): 105–108.

171. Often the internal aspect has a multilocular appearance. The septa bear a striking resemblance to the wispy, illdefined septa seen in giant cell granulomas . Another similar finding is septa positioned at right angles to the outer expanded border.

172. Effects on Surrounding Structures.: After an ABC becomes large, expansion of the outer cortical plates and root reeorption may be seen. Histologic Features. The aneurysmal bone cyst consists of a fibrous connective tissue stroma containing many cavernous or sinusoidal blood-filled spaces. These spaces may or may not show thrombosis.

173. Young fibroblasts are numerous in the connective tissue stroma , as well as multinucleated giant cells with a patchy distribution similar to that in the giant cell granuloma . But in the latter lesion the cavernous spaces are not found . Varying amounts of hemosiderin are present and, invariably, new osteoid and bone formation

174. D/D The multilocular appearance of ABCs most resembles that of giant cell granulomas ; in fact, the radiographic appearance of the two lesions may be identical. However, ABCs may expand to a greater degree, and they are more common in the posterior parts of the mandible.

175. Ameloblastoma may be considered, but this lesion usually occurs in an older age group. ABCs may show a similarity to cherubism , which has giant cell – like features, but cherubism is a multifocal bilateral disease. Hemorrhagic aspirate is seen in abc Treatment Surgical curettement or excision is the treatment of choice,

176. Differential diagnosis of fibro-osseous lesions Radiolucent lesions - Unicystic radiolucency with sclerotic margin- Cyst- radiolucency will be smooth, thin and sharply defined. Tooth will be vital and aspiration shows positive response. Unilocular radiolucency without sclerotic margin with ill defined margins should be differentiated with malignancies. Root resorption will also be seen in all malignant lesions. Multilocular radiolucent lesion Locules of trabeculae might be few in number and of poor density like central giant cell granuloma or it may be coarse and thick resembling like ameloblastoma

177. Mixed radiolucent and radioopaque lesions - Periapical cement osseous dysplasia Malignant metastatic lesions like osteogenic sarcoma and osteoblastic carcinoma Fibrous dysplasia Condensing osteitis Cement-ossifying fibroma Periapical cement osseous dysplasia- radiolucent lesion surrounds the apex of the tooth, with either sclerotic margin or opaque masses within the lucent lesion. Tooth will be vital, absence of pain, no expansion of cortices

178. Malignant metaststic lesions like osteogenic sarcoma and osteoblastic carcinoma appears as mixed radiolucent – radioopaque lesions but they are usually irregular and ill defined along with root resorption which is not seen in fibro-osseous lesions. Odontoma - it is usually located above the crown of an unerupted tooth and seldom it is found in the apical region . these are more radioopaque compared to fibroosseous lesions.

179. Fibrous dysplasia- common in maxilla, seen in 1 st and 2 nd decade of life. Has equal predilection for both male and female. Jaw expansion is seen which is of fusiform type. there is no line of demarcation between normal bone and defective bone. Condensing osteitis - clinically pain, inflammation, drainage, tenderness on palpation and regional lymphadenitis will be present. Cement-ossifying fibroma - predilection for premolars and molars. Seen under 30 years . Attains size of 2 to 4 cm, produces discernible expansion.

180. Mixed radiolucencies and radioopacities not necessarily contacting teeth Fibrous dysplasia Chronic osteomyelitis Cement-ossifying fibroma Pagets disease Chondrosarcoma Radio-opaque lesions- Fibrous dysplasia Focal sclerosing osteomyelitis Diffuse sclerosing osteomyelitis Focal cement-osseous dysplasia.

181. Conclusion : The Fibro- osseus lesions of the jaws comprise a diverse, interesting, and challenging group of conditions that pose difficulties in classification and treatment. Common to all is the replacement of normal bone by a tissue composed of collagen fibers and fibroblasts that contain varying amounts of mineralized substance, which may be bony or cementum -like in appearance. A definitive diagnosis of a Fibro- osseus lesion requires correlation of the histologic features with the clinical, radiographic, and intraoperative findings. Despite the advances in the understanding of these conditions, fibro-osseous lesions continue to present problems in classification, diagnosis, and management due to multiple histological and radiographic similarities.

182. References : A textbook of oral pathology: shafer , hine and levy: 5 th edition Burket’s oral medicine: 11 th edition Differential diagnosis of oral lesions: wood and goaz : 3 rd edition . Oral pathology . Regezi & scuibba.4 th edition. Oral & maxillofacial pathology. Neville 2 nd edition Oral radiology, principles and interpretation, 4 th edition, white and pharoah . Current concepts review fibrous dysplasia pathophysiology , evaluation, and treatment mathew r etal . The journal of bone and joint surgery 2005 The radiological versatility of fibrous dysplasia: An 8-year retrospective radiographic analysis in a north Indian population , praksah.R etal ,  journal of dentistry 2014; 5(3):139-145. Peñarrocha et al. Cherubism . J Oral Maxillofac Surg 2006.

183. Fibro-osseous lesions of the jaws: An insight. Chauhan I etal International Journal of Contemporary Dental and Medical Reviews (2014), Article ID 071214, Fibrous Dysplasia and Ossifying Fibroma - an advent in their diagnosis Gulati A J Clin Exp Dent. 2011;3(4):e297-302. Fibro Osseous Lesions – Classifications, Pathophysiology and Importance of Radiology: a Short Review Srichinthu.KK Int. Biol. Biomed. J. Winter 2016; Vol, 2 No 1:1-10. Aneurysmal bone cyst of the mandible: A case report and review of literature Devi PJ Oral Maxillofac Pathol . 2011;15(1): 105–108. An Unusual Presentation of a Central Giant Cell Granuloma and Initial Treatment with Intralesional Steroids– A Case Report and Review of the Literature. Richard M Graham et alJ Oral Health Comm Dent 2008;2(3):65-69