FIBRO-OSSEOUS LESIONS.pptx final year bds

Final year bds

1. FIBRO-OSSEOUS LESIONS FATHIMA FELLAH K 3 RD YEAR

2. CONTENTS Introduction Classifications Common features Fibrous dysplasia - monostotic - polyostotic Ossifying fibroma Cemento ossyfing fibroma Paget’s disease Conclusion Reference

3. INTRODUCTION

4. CLASSIFICATIONS Waldron's classification of fibro-osseous lesions Fibrous dysplasia. Polyostotic Monostotic Reactive (dysplastic) lesions in the tooth bearing area presumably of the periodontal ligament origin Periapical cemento -osseous dysplasia Focal cemento -osseous dysplasia Florid cemento -osseous dysplasia. Fibro-osseous neoplasms Cemento -ossifying fibroma Ossifying fibroma Cementifying fibroma

5. WHO Classification of FOLs, 2005 Ossifying fibroma (OF ) Fibrous dysplasia. Osseous dysplasia Periapical osseous dysplasia Focal osseous dysplasia Florid osseous dysplasia Familial gigantiform cementoma Central giant cell granuloma Cherubism Aneurysmal bone cyst Solitary bone cyst

6. COMMON FEATURES Painless Slow growing Bony hard masses Asymmetry of the affected bone may be evident . Arise from both maxilla & mandible. Mandible > maxilla Females > males Usually occurs in second to fourth decade of life Accidentally found in radiographs.

7. FIBROUS DYSPLASIA

8. Fibrous dysplasia is a condition characterised by re placement of normal bone by an excessive proliferation of fibrous connective tissue intermixed with irregular bony trabeculae. There is arrest of bone development in woven bone stage with failure to mature to lamellar bone. It is a congenital dysplastic disease of bone. It is a benign but ,at times destructive disease.

9. PATHOGENESIS Exact aetiology of this condition is not known . Usually caused by a mutation in the GNAS-1 gene on chromosome 20 - formation of excess CAMP in mutated cells . ( guanine nucleotide binding protein, alpha stimulating ) Gene encodes a G-protein that stimulates the production of CAMP . The increase in CAMP - prevents the differentiation of cells within the osteoblastic lineage.

10. Two forms of fibrous dysplasia have been described Monostotic -where one bone is involved . Polyostotic -where several bones are involved along with cutaneous and endocrine abnormalities

11. MONOSTOTIC FIBROUS DYSPLASIA It is more common than the polyostotic form and accounts for 80% of cases (Fig. 28.3А-Г ) It is characterised by local but poorly circumscribed fibro-osseous replacement of an area of bone. The jaws, particularly the maxilla, is the most frequently affected site Frontal bone is the other bone in the craniofacial skeleton that is commonly involved. Other frequently involved bones: ribs, femur , long bones and skull.

12. CLINICAL FEATURES Onset of the disease usually occurs during the 1stor 2nd decade of life . Males and females are equally affected The lesion forms a diffuse painless, smooth rounded swelling It is usually but not always unilateral. As the lesion grows and expands facial asymmetry develops .

13. Buccal cortical plate expansion is common . Displacement of teeth can cause malocclusion Interference with normal eruption of teeth may occur While the disease develops in the maxilla, outer surface of the alveolar process is extremely enlarged . Normal occlusion is often seen, as normal teeth erupt . Maxillary lesions frequently involve adjacent bones such as zygoma , sphenoid, maxillary sinus and floor of orbit.

14. In the mandible, the mandibular body area is most frequently affected.

15. RADIOGRAPHIC FEATURE Typical appearance is a homogeneous radiopacity with numerous trabeculae of woven bone giving a ground glass or orange peel appearance. An important feature is that the lesion merges imperceptibly with surrounding normal bone without a circumscribed border . The lesion may also present as a radiolucent area with patchy irregular opacities.

16. HISTOPATHOLOGIC FEATURE Consists of areas of loose cellular fibrous tissue interwoven with irregular trabeculae and newly formed bone . The trabeculae are discrete, slender and accurate or branched. Some are slender and C-shaped called 'Chinese characters' trabeculae Osteoblasts are scattered throughout the substance of the trabeculae . Lamellar bone formation is not seen in the classic microscopic picture of fibrous dysplasia

17. POLYOSTOTIC FIBROUS DYSPLASIA Polyostotic fibrous dysplasia is more uncommon (Fig. 28.4A-D ) Several or many bones may be involved . Females are more often affected in a ratio of 3:1. When seen with cutaneous pigmentation (café-au- lait macules), the disease is termed Jaffe-Lichtenstein syndrome . Polyostotic fibrous dysplasia is more frequent in childhood.

18. McCune-Albright syndrome comprises polyostotic fibrous dysplasia, skin pigmentation and endocrine abnormalities. Precocious sexual development and onset of puberty in females is the common endocrine disorder. Involves head and neck region in 50%of cases. A jaw lesion may be the most conspicuous feature Skin pigmentation consists of brown macules 1 cm or more with an irregular outline .

19. Risk of sarcomatous change is greater in polyostotic

20. TREATEMENT Radiotherapy is contraindicated because of its potential for malignant transformation as it may lead to post radiation bone sarcoma Small lesions may only require biopsy for confirmation and periodic follow-up. Lesions that cause functional disability or cosmetic deformity are treated by osseous recontouring .

21. Surgical intervention is generally done following active growth stage and during the period of the disease process of stabilisation . Entire disease cannot be eradicated by surgery, it is only a sculpting manoeuvre to improve the patient's appearance and provide a better functional masticatory apparatus Complete excision of the lesion is not possible because of the diffuse nature of the lesion and poorly defined borders .

22. In many cases, disease tends to stabilise and essentially stops enlarging when skeletal maturation is reached . Adolescents have the potential for continued progression of the dysplastic process after surgery, so treatment is delayed as long as possible. Lesions involving anterior wall of the maxilla and the zygoma can be approached intraorally .

23. Extension of the lesion into the nasal or posterior maxillary areas require an extraoral approach through a Weber-Ferguson facial flap . Lesions of the mandible connected to the alveolar ridges or inner aspect of mandible are approached intraorally , whereas lesions in the posterior mandible are best accessed through a submandibular incision.

24. OSSIFYING FIBROMA

25. COF progressive painless buccal and lingual plate expa n sion . COF affects denute segment of mandible and maxilla They are slow growing in nature in adults, but show aggressiveness in the younger age group. The teeth are generally displaced. The peak age is 3rd and 4th decades of life and very strong female predilection (almost 5:1).

26. Ossifying Fibromas demonstrate a well delineated or encapsulated cellular fibrous connective tissue with varying amounts of osseous products like bone and cementum (spherical calcification ). Lesions are more commonly seen in mandible (77%) especially the molar region and are found exclusively in jaws. The juvenile variant (Juvenile-Ossifying Fibroma), which is also more aggressive , is seen in the younger age group [ 23

27. RADIOGRAPHIC FEATURE It is a well-demarcated radiolucent lesion, in the initial stages, separated from the surrounding healthy bone. Usually , a solitary lesion and is unilocular . The well-demarcated radiolucent/radiopaque appearance is the main differentiating consideration with Fibrous Dysplasia.

28. Appearance is dependent on the maturity of the lesion, i.e. purely radiolucent (initial stages); mixed with radiopaque foci or radiopaque. The radiographic presentation of bowing of mandible with thinning and weakening of the lower border, particularly in large expansive lesions, is seen. Resorption or divergence of roots may result due to continued growth

29. HISTOPATHOLOGIC FEATURE Ossifying fibromas of craniofacial skeleton are divided into two categories depending on the cell of origin . Cemento -ossifying Fibroma (COF): OF with odonto genic origin . Juvenile (aggressive)-Ossifying Fibroma [9, 24-26]: subscategorised as (Table 30.1) (Fig 30.7 ) Juvenile trabecular-Ossifying Fibroma ( JTOF) Juvenile Psammomatoid -ossifying fibroma (JPOF)

30. JTOF JPOF Age 2-30 yrs 3 mouits-72 years ( Female : male 1.2 : 1 1:3:4 Site Maxilla 50 % Mandible 44% Sino nasal 6% Sino-nasal 62% Maxilla 20% Mandible ramus 10% Cranium 8% Radiology Well circumscribed Speckled calcifications Well circumscribed aggressive, expands and occupies the parnasal sinuses histopathology Densely cellular ,immature bone and osteoid in a trabecular pattern, osteoblast rimming seen Densely cellular,spherical cementum-like psammomatoid calcifications Clinical features Progressive and rapid expansion of lesion, pain may not be present, in maxilla can produce nasal obstruction and epistaxis. Affects predominantly extragnathic bones of craniofacial skeleton, particularly the paranasal, orbital, frontal and ethmoid bones. Orbital extension of sino -nasal tumors may present as proptosis visual complaints nasal stuffiness etc

31. TREATEMENT AND PROGNOSIS COF is a slowly growing benign neoplasm, if left untreated can enlarge to a significant size . It is curettage or enucleation a preferred initial treatment option (as it is radiographically as well as microscopically well circumscribed and shells out from the surrounding bone with little effort) An important feature is, it is well defined and can be easily shelled out from the adjoining normal bone, grossly the lesion can be separated out in one piece or a few large chunks.

32. CEMENTO-OSSEOUS DYSPLASIA(Osseous Dysplasia)

33. N eoplastic , commonest, least understood fibro osseous lesion occurring in tooth bearing areas of the jaws. Its due to similarities with o ther fibro-osseous lesions like fibrous dysplasia and ossifying fibroma and even few neoplasias Since these lesions lie in close association with the periodontal ligaments of the tooth-bearing segment of the jaws, and histopathologically as well, they bear close similarity with PDL, the strong suspicion of the origin in PDL cannot be ruled out.

34. Two main types are recognised, based on the clinical and radiological features . Localised Periapical cemento osseous dysplasia (PCOD ) Focal cemento osseous dysplasia (FCOD ) Generalised. Florid cemento osseous dysplasia

35. PCOD FCOD FL .COD At the apica l aspect of vital mandibular anteriorteeth Mostly in black and Asians Women>men >40 yrs Vital teeth Enlarge slowly Radiolographic examination Asyasymptomatic No treatment At apical aspect of posterior teeth Whites and Caucasians Women> men Biopsy and histologic examination Asyasymptomatic No treatment Involves multiple quadrents of both jaws Blacks and Asians Women> men Radiolographic -mixed or radiopaque Well defined with sclerotic border Poor vasular supply Asymptomatic No treatment

36. Treatment/Management The modified osseous tissue is prone to infection, hence any local causes of infection-like periapical pathosis , periodontal disease , ill-fitting dentures can lead to osteomyelitis of the unerlying altered bone and fistula and sequestra formation . It is commended to avoid any surgical intervention for diag nos tic purposes, as the diagnosis is generally made on clinical in radiographic presentation.

37. As for the treatment of symptomatic lesions like the presence of underlying osteomyelitis,conservative care in the form of removal of sequestra and prolonged antibiotic therapy is recommended. Extractions are not mended for the same reason, as the socket heals by replacement with cementum-like tissue, which is mainly avascular. Surgical intervention in terms of the debulking procedures is only recommended where there is obvious facial deformity resulting in reduced quality of life

38. PAGET'S DISEASE OF BONE (OSTEITIS DEFORMANS)

39. Paget's disease of bone is a disease characterised by abnormal and anarchic resorption and deposition of bone, resulting in distortion and weakening of the affected bones. Causes of Paget's disease are unknown, but inflammatory, genetic and endocrine factors may be contributing agents..

40. CLINICAL FEATURES P rincipally affects older people and is rarely encountered in patients below 40 years of age . Men are affected more often than women . Lumbar vertebrae, pelvis, skull and femur are the most commonly affected bones . Affected bones become thickened, enlarged and weakened. . Paget's disease affecting the skull generally leads to a progressive increase in the circumference of the head

41. Maxillary disease, which is far more common than mandibular involvement, results in enlargement of the middle third of the face. In extreme cases, alteration results in a lion-like facial deformity (leontiasis ossea ).

42. Nasal obstruction, enlarged turbinates , obliterated sinuses and deviated septum may develop secondary to maxillary involvement. Alveolar ridges tend to remain symmetric but become grossly enlarged. If the patient is dentulous, enlargement causes spacing of the teeth

43. RADIOGRAPHIC FEATURE Radiographically , early stage of Paget's disease reveals a decreased radiodensity of the bone and alteration of the trabecular pattern . Particularly in the skull, large circumscribed areas of radiolucency may be present. During osteoblastic phase of the disease, patchy areas of sclerotic bone are formed, which tend to become confluent . Patchy sclerotic areas are often described as having a 'cotton wool' appearance

44. HISTOPATHOLOGIC FEATURE S hows an apparent uncontrolled alternating resorption and formation of bone. In the active resorptive stages, numerous osteoclasts surround bone trabeculae and show evidence of resorptive activity . A characteristic microscopic feature is the presence of basophilic reversal lines in the bone . These lines indicate the junction between alternating resorptive and formative phase of the bone and result in a 'jigsaw puzzle' or 'mosaic' appearance of the bone.

45. Diagnosis Patients with Paget's disease show high elevations in serum alkaline phosphatase level and normal blood calcium and phosphorus levels along with elevated urinary hydroxyproline levels. Newer and more sensitive markers of bone resorption as N- telopeptides and pyridinoline cross-link assays are available

46. Treatment and prognosis Although Paget's disease is chronic and slowly progressive , it is seldom the cause of death . Patients with limited involvement and no symptoms , often require no treatment. Use of parathyroid hormone antagonists, such as calcitonin and biphosphonates can reduce bone turnover and improve biochemical abnormalities.

47. In many instances, acceptable control has been obtained with the newer biphosphonates , such as etidronate , pamidronate , alendronate, tiludronate or risedronate . In mild cases, a single infusion of a biphosphonate is often associated with year long remissions . Development of a malignant bone tumour , usually an osteosarcoma is a recognised complication of Paget's disease.

48. CONCLUSION

49. REFERENCE