This document provides information on fibro-osseous lesions of the jaw, specifically focusing on fibrous dysplasia. It discusses the classification, etiology, pathogenesis, clinical features, radiographic features, and histological features of fibrous dysplasia. Key points include that fibrous dysplasia is caused by a mutation in the GNAS1 gene, it can present as monostotic, polyostotic, or craniofacial forms, and radiographically demonstrates a "ground glass" or "peau d'orange" appearance with thinning of the cortical bone. Histologically there is replacement of normal bone by proliferating fibroblasts in a compact stroma.

1. FIBRO-OSSEOUS LESIONS OF
THE JAW
Guided by- Dr. Himanshu Chauhan
(Sr. Lecturer OMFS)
Presented by- Dr. Mrinalini Mathur

2. INTRODUCTION
- Fibro- osseous lesions of the jaws include developmental (hamartomatous)
lesions, reactive or dysplastic processes, and neoplasms.
- Histologically, these group of fibro-osseous lesions are characterised by the
replacement of normal bone by fibrous connective tissue matrix. The fibrous
tissue displays variable features like varying degree of mineralization in the
form of woven bone or cementum like basophilic structures .

3. DEFINITION
-Waldron described fibro osseous lesions as a group of pathological changes
within the jaw bones in which the normal bone is replaced by fibrous tissues
with or without calcification.
-Goaz and White stated that fibro osseous lesions are a group of conditions that
replace normal bone with benign fibrous tissues containing variable amount of
mineralization.

4. CLASSIFICATION SCHEMES OF
FIBRO-OSSEOUS LESIONS
1. Charles Waldron Classification Of The Fibro-Osseous Lesions Of The Jaws(1985)
2. Working Classification Of The Fibro-Osseous Lesions By Mico M. Malek(1987)
3. Peiter J. Slootweg And Hellmuth Muller(1990)
4. WHO Classification (1992)
5. Waldron Modified Classification Of Fibro-Osseous Lesions Of Jaws(1993)
6. Brannon And Fowler Classification (2001)
7. WHO Classification Of Fibro- Osseous Lesions Of Jaws( 2005)
8. Paul M. Speight And Roman Carlos Classification( 2006)
9. Eversole Classification ( 2008)

5. CHARLES WALDRON CLASSIFICATION OF THE FIBRO-OSSEOUS
LESIONS OF THE JAW(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 Lesion
c. Florid Cement-Osseous Dysplasia
d. Ossifying And Cementifying Fibroma
3. Fibro- Osseous Neoplasms Of Uncertain Or Detectable Relationship To Those Arising In The
Periodontal Ligament( Category II)
a. Cementoblastoma, Osteoblastoma And Osteoid Osteoma
b. Juvenile Active Ossifying Fibroma And Other Aggressive, Active Ossifying/ Cementifying
Fibromas

6. WORKING CLASSIFICATION OF FIBRO-OSSEOUS LESIONS BY MICRO M.
MALEK(1987)
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 And Florid Cemento- Osseous Dysplasia
e. Sclerosing Osteomyelitis( Focal and Diffuse Type)
f. Osteitis Deformans
3. Fibromatosis
Desmoplastic Fibroma ( Intraosseous Fibromatosis)

7. 4. Neoplasms
a. Tooth Bearing Areas Only
i) Cementoblastoma
ii) Periodontoma
-Central
- Peripheral
b. All Cranio- Facial Bones( Including Tooth Bearing Areas)
i)Osteoma
- Trabecular
-Compact
ii) Osteoid Osteoma
iii) Psammous Desmo- Osteoblastoma
iv) Trabecular Desmo- Osteoblastoma

8. PEITER J. SLOOTWEG AND HELLMUTH MULLER(1990)
In 1990 Peiter J. Slootweg And Hellmuth Muller gave a classification that laid emphasis
primarily on the histological features, and they underscore that this classification requires
inclusion of adjacent normal bone to make diagnosis.
However in the absence of this, the clinical and radiological features have to be taken in
consideration.
Group 1: Fibrous Dysplasia
Group 2 : Juvenile Ossifying Fibroma
Group 3: Ossifying Fibroma
Group 4: Periapical Cemental Dysplasia And Florid Osseous Dysplasia

9. WHO CLASSIFICATION(1992)
1. Osteogenic Neoplasms
Cemento- ossifying fibroma( Cementifying Fibroma, Ossifying Fibroma)
2. Non- Neoplastic Bone Lesions
a. Fibrous Dysplasia Of Jaws
b. Cemento- Osseous Dysplasia
- Periapical Cemental Dysplasia
- Florid Cemento- Osseous Dysplasia
- Other Cemento- Osseous Dysplasia
c. Cherubism ( Familial Multilocular Cystic Disease Of The Jaws)
d. Central Giant Cell Granuloma
e. Aneurysmal Bone Cyst
f. Solitary Bone Cyst ( Traumatic, Simple, Haemorrhagic Bone Cyst)

10. WALDRON MODIFIED CLASSIFICATION OF FIBRO-OSSEOUS LESIONS
OF THE JAWS(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 Fibroma
b. Ossifying Fibroma
c. Cemento- Ossifying Fibroma

11. BRANNON AND FOWLER CLASSIFICATION
1. Osseous Dysplasia( Reactive)
a. Nonhereditary
- Periapical
-Focal
-Florid
b. Hereditary( Developmental)
Familial Gigantiform Cementoma
2. Fibro- Osseous Neoplasm
a. Ossifying Fibroma
b. “Juvenile” ,” Active” or “ Aggressive” Variants Of Ossifying Fibroma

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

13. WHO CLASSIFICATION OF FIBRO-OSSEOUS LESIONS OF JAWS( 2005)
1. Ossifying Fibroma
2. Fibrous Dysplasia
3. Osseous Dysplasia
-Periapical Osseous Dysplasia
-Focal Osseous Dysplasia
-Florid Osseous Dysplasia
-Familial Gigantiform Cementoma
4. Central Giant Cell Granuloma
5. Cherubism
6. Aneurysmal Bone Cyst
7. Solitary Bone Cyst

14. PAUL M. SPEIGHT AND ROMAN CARLOS
CLASSIFICATION(2006)
1. Fibrous Dysplasia
a. Monostotic Fibrous Dysplasia
b. Polyostotic Fibrous Dysplasia
c. Craniofacial Fibrous Dysplasia
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

15. EVERSOLE CLASSIFICATION (2008)
1. Bone Dysplasia
a. Fibrous Dysplasia
-Monostotic
-Polyostotic
-Polyostotic With Endocrinopathy( McCune-Albright)
-Osteofibrous Dysplasia
b. Osteitis Deformans
c. Pagetoid Heritable Bone Dysplasia Of Childhood
d. Segmental Odontomaxillary Dysplasia
2. Cemento-Osseous Dysplasia
a. Focal Cemento-osseous Dysplasia
b. Florid Cemento-osseous Dysplasia

16. 3. Inflammatory/ Reactive Processes
a. Focal Sclerosing Osteomyelitis
b. Diffuse Sclerosing Osteomyelitis
c. Proliferative Periostitis
4. Metabolic Disease: Hyperparathyroidism
5. Neoplastic Lesions
a. Ossifying Fibroma
b. Hyperparathyroidism Jaw Lesion Syndrome
c. Juvenile Ossifying Fibroma
- Trabecular Type
- Psammomatoid Type
d. Gigantiform Cementomas

17. FIBROUS
DYSPLASIA

18. INTRODUCTION
-Term coined by LOUIS LICHENSTEIN in 1938
- First described by VON RECKLINGHAUSEN in 1891
- "It is a nonheritable, genetic disorder characterized by the replacement of normal
bone by immature, randomly distributed bony and fibrous tissues”.
-The resultant fibro-osseous bone is more elastic and structurally weaker than the
original bone.
- It is also known as:
i.) Fibrocystic disease
ii.)Osteitis fibrosa localista
iii.)Focal osteitis fibrosa
iv.)Fibro-osteodystrophy

19. CLASSIFICATION OF FIBROUS
DYSPLASIA

21. ETIOLOGY
- Exact cause of fibrous dysplasia is not known.
- Usually caused by a mutation in the GNAS 1 gene.
- Gene encodes a G- protein that stimulates the production of cAMP.
- Continuous activation of the G- protein leading to overproduction of cAMP in the affected
tissues.
- cAMP is thought to have an effect on the differentiation of osteoblasts leading to fibrous
dysplasia.

22. PATHOGENESIS OF FIBROUS
DYSPLASIA(MOLECULAR BASIS)

23. GENETIC DEFECTS
The time at which the genetic alterations occur is before the sixth week of foetal life.
- If the genetic defect occurs during postnatal life = monostotic fibrous dysplasia.
- If the genetic defect occurs late in embryonic development = polyostotic fibrous dysplasia.
-If the genetic defect occurs during early embryonic life = McCune-Albright syndrome or the
Jaffe- Lichtenstein type of polyostotic fibrous dysplasia.

26. THREE DISEASE PATTERNS ARE RECOGNISED
1. Monostotic Form
2. Polyostotic Form
3. Craniofacial Form
FIBROUS
DYSPLASIA
MONOSTOTI
C
FIBROUS
DYSPLASIA
POLYSTOTIC
FIBROUS
DYSPLASIA
70% 30%

27. MONOSTOTIC FIBROUS DYSPLASIA
-Involves a single focus in one bone.
- Seen frequently in the rib(28%), femur(23%), tibia, craniofacial bones( 10- 25%), and humerus.
- Seen most frequently in the body of the mandible or in the premolar- molar regions of the
maxilla.

28. CLINICAL FEATURES
- Equal predilection for males and females.
-Mean Age of occurrence is 27-34 years.
-The first clinical sign of the disease is a painless swelling or bulging of the jaw.
- The swelling usually involves the labial or buccal plate, seldom the lingual aspect.
- Tipping or displacement of the teeth due to the progressive expansile nature of the lesion.
-Mucosa is almost invariably intact over the lesion.

29. RADIOGRAPHIC FEATURES
Three basic patterns are seen:
- In one type, the lesion is a small unilocular radiolucency or a somewhat multilocular
radiolucency both with a rather well-circumscribed border and containing a network of fine bony
trabeculae.
-In the second type, the pattern is similar except that increased trabeculation renders the lesion
more opaque and typically mottled in appearance.
-The third type shows a ‘ground glass’ or ‘ peau d’ orange’ appearance to the lesion. It is not well
circumscribed but instead blends into the adjacent normal bone.
( In all types, the cortical bone becomes thinned because of the expansile nature of the growth
but the bone is seldom perforated. Roots maybe separated or moved out of normal position.)

30. TYPE- 1
TYPE-2

31. EARLY AND ADVANCED LESIONS
MONOSTOTIC FIBROUS DYSPLASIA:
GROUND GLASS CHANGE WITH AREAS OF SCLEROSIS
AND ILL
DEFINED BORDERS

32. A- EXPANSILE NONMARGINATED
GROUND GLASS OPACIFICATION IN
THE MANDIBLE
B- GROUND GLASS PATTERN IN THE
MAXILLA
A- GROUND GLASS PATTERN
B- COTTON WOOL
C- ORANGE PEEL

33. AN OCCLUSAL VIEW OF FIBROUS DYSPLASIA WILL SHOW ITS DIFFUSE”
GROUND-GLASS” APPEARANCE, EXPANSION AND FIBROUS DYSPLASIA
REPLACEMENT OF THE CORTICAL OUTLINE

34. HISTOLOGICAL FEATURES
- Proliferating fibroblasts in a compact stroma of interlacing collagen fibers.
- Irregular trabeculae of bone( woven bone) scattered throughout the lesion with no definite
pattern of arrangement.
- Some trabeculae are typically C, S shaped, Jig Saw puzzle or has Chinese letter
appearance.

37. POLYOSTOTIC FIBROUS
DYSPLASIA
- Involves the skull and facial bones, pelvis, spine and shoulder girdle.
-Mostly unilateral.
-Initial symptom is pain in the involved limb associated with a limp, spontaneous fracture, or
both.
-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.

38. SHEPHERD’S CROOK DEFORMITY COXA VARA

39. TYPES-
There are two types of polyostotic fibrous dysplasia-
1.Fibrous dysplasia involving a variable number of bones, although most of the skeleton is
normal, accompanied by pigmented lesions of the skin or
‘’CAFÉ-AU-LAIT” spots( Jaffe’s type).
2. Fibrous dysplasia involving nearly all bones in the skeleton accompanied by pigmented lesions
of the skin along with endocrine disturbances of varying types
( Albright’s syndrome).

40. MCCUNE – ALBRIGHT SYNDROME
- Described by Fuller Albright in 1937.
- Occurs due to a post zygotic activating mutation of the GS alpha gene in the affected tissues.
- Clinical features-
:Precocious puberty
:Hyperthyroidism
:Acromegaly
:Hyperprolactinemia
:Cushing syndrome
:Hyperparathyroidism

42. MAZABRAUD’S SYNDROME
- Association of fibrous dysplasia and intramuscular myxoma.
- Occurs due to underlying localized error in tissue metabolism.
- Greater risk of sarcomatous transformation in fibrous dysplasia with Mazabraud’s syndrome has
been reported.

43. RADIOGRAPHIC FEATURES
-Radiolucent lesion in the diaphysis or metaphysis, with endosteal scalloping with or without
bone expansion and the absence of periosteal reaction.
- The lucent lesion has a thick sclerotic border and is called the RIND SIGN.

44. RIND SIGN

45. ORAL MANIFESTATIONS
- Mostly seen in maxilla.
-Expansion and deformity of the jaw.
-Eruption pattern of the teeth is disturbed because of the loss of normal support of the
developing teeth.
-Time of eruption is also altered.

46. HISTOLOGIC FEATURES
-Fibrillar connective tissue which has numerous trabeculae of coarse, woven
immature bone which is irregular in shape.
-Large osteocytes are seen whereas osteoblasts are absent( no osteoblastic
rimming).

47. CRANIOFACIAL FIBROUS
DYSPLASIA
- Involves two or more bones of the jaw-midface-skull complex in continuity.
- Mostly involves the frontal, sphenoid, maxillary and ethmoid bones.
- Presents at 10 years of age and then progress throughout adolescence.
- It ranges from a mild local swelling with little or no pain to a gross deformity.

48. DIAGNOSIS OF FIBROUS
DYSPLASIA
1. Imaging studies including CT Scan and MRI.
2. Nuclear scintigraphy.
3. Biopsy
4. Analysis of GNAS1 gene.
5. Lab studies to document endocrine disturbances.

49. DIFFERENTIAL DIAGNOSIS
1- Ossifying fibroma: mostly in old age
: spherical to egg shaped
: well demarcated from normal bone
2- Chronic sclerosing osteomyelitis: common in adults
: constantly and severely painful
: history of endodontic therapy, an abscessed
tooth or some other infection.
: presence of sequestrum.
3- Paget’s Disease : in individuals older than 40 years
: increased alkaline phosphatase levels.

50. TREATMENT
1. Observation
2. Medical therapy
3. Surgical Remodelling
4. Radical excision and reconstruction

51. OBSERVATION:
- Serial radiographs, CT Scan and clinical examination.
-Monostotic fibrous dysplasia and craniofacial fibrous dysplasia require no treatment.
-Most children adapt well to the facial expansion and do not desire osseous contouring surgery.
-If osseous contouring surgery is desired, it is ideal to defer it until adulthood ( 18-21 years).

52. MEDICAL TREATMENT:
1. Bisphosphonates
2. Systemic steroids
-Bisphosphonate therapy has been utilized for patients with symptomatic polyostotic disease.
-Pamidronate given i.v. in 500ml of normal saline at a dosage of 30mg over 4 hours for 3
consecutive days. Response to this therapy lasts for 3 to 6 months.
-The major effect of bisphosphonate therapy was decreased bone pain and improved skeletal
bone strength, can also slow down bony expansion.

53. BISPHOSPHONATES

54. SURGICAL RECONTURING

55. RADICAL EXCISION AND RECONSTRUCTION:
-Shows episodic growth, high chances of regrowth to occur post surgically.
- So surgery is avoided during a period of active expansion.
- Resection is avoided unless neural compression threatens vision or hearing. In such cases local
resection around the area of the nerve compression is done.
- In the jaws there is mostly no functional impairment therefore jaw resection and
reconstruction is not done unless the patient’s function and appearance are significantly altered
and osseous contouring is not an option.

56. ZONE 1- Radical excision and reconstruction with bone grafts
ZONE 2- Conservative or resection
ZONE 3- Observation
ZONE 4- Conservative management, shaving and recontouring

57. REFERENCES
-Shafer’s textbook of oral pathology.
-Textbook of Oral Medicine- Anil Govindrao Ghom.
-Neville, Damm,Allen, Bouquot. Oral And Maxillofacial Pathology.

58. THANK
YOU