fibro- osseous leions of the jaws

1. FIBRO-OSSEOUS LESIONS
“The term fibro-osseous lesion (FOL) is a
generic designation of a group of jaw
disorders” characterized by the
replacement of bone by a benign
connective tissue matrix.
This matrix displays varying degrees of
mineralization in the form of woven bone
or of cementum-like round acellular
intensely basophilic structures.

2. 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
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.

3. Eversole Classification, 2008

4.  By definition, all benign fibro-osseous
lesions possess an osseous and fibrous
tissue component.

5.  The ossifications in BFOL can be quite
heterogeneous even within a specific
disease entity.
 Newly formed bone - woven pattern of
collagen fiber orientation.
 Mature bone - lamellar pattern.
 Many have both irregular trabeculae
as well as spheroidal cementicle
calcifications, so called “ Cemento-ossifying”
lesions.

6.  The ossification patterns represent the
“age” of the lesion.
Early stages- more cellular and
osteoblastic rimming of trabeculae is
more prominent.
Older lesions - stroma is more mature.

7. FIBROUS DYSPLASIA
 Lichtenstein,1938
 It is a disease of bone maturation and
remodeling in which the normal medullary
bone and cortices are replaced by a
disorganized fibrous woven bone.
 The resultant fibro-osseous bone is more
elastic and structurally weaker than the
original bone.
 Caused by postzygotic mutation in the
GNAS1 gene.
 Mutations of the GSa gene
 No hereditary influence.

8. Investigation of the GSa gene in
the diagnosis of fibrous
dysplasia
 Done by direct sequencing of the Gsa
gene.
 High prevalence of GSa gene
mutations in fibrous dysplasia.
Int. J. Oral Maxillofac. Surg. 2004; 33: 498–501
Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:618-
626

9. Types of Fibrous Dysplasia
Forms of presentation of fibrous dysplasia
Bone Involvement
Single Multiple Cafἐ au
Lait Spots
Endocrine
disorders
Soft-tissues
masses
Monostotic X
Polyostotic X
McCune
Albright
Syndrome
X X X
Mazabrau
d disease
X X

10.  If the mutation occurs during early
embryologic life
Multiple bone lesions, Cutaneous
pigmentation and endocrine
disturbances

11.  If the mutation occurs during later
stages
Multiple bone lesions
 If the mutation occurs during postnatal
life
Affects single bone

12. Monostotic Fibrous Dysplasia
 Limited to a single bone.
 Accounts for 80% to 85% of all cases
 M:F = 1:1
 Painless swelling.
 Growth is generally slow but occasionally
rapid.
 Maxilla > Mandible.
 60% of cases causes displacement of
mandibular canal.
 Often detected during the first two
decades of life.
Fibro-osseous Iesions of the jaws. J Oral MaxilIofac Surg 43:249, 1985

13.  Mandibular lesions are truly
monostotic.
 Maxillary lesions often involve
adjacent bones(e.g., zygoma,
sphenoid, occipital)
Craniofacial Fibrous Dysplasia.

14. Polyostotic Fibrous dysplasia;
Jaffe-Lichtenstein Syndrome;
McCune – Albright Syndrome
 Involvement of two or more bones.
 When seen with cafἐ au lait
pigmentation  Jaffe- Lichtenstein
syndrome.
 Polyostotic fibrous dysplasia + cafἐ au
lait pigmentation + multiple
endocrinopathies  McCune Albright
Syndrome.

15.  Causes facial asymmetry.
 Pathologic fractures with pain and
deformity.
 Leg length discrepency is common
due to involvement of upper portion of
the femur ( Hockey Stick deformity).

16. Radiographic Features
 Depends upon the stage of the
disease.
 Early onset lesions are radiolucent
and later progressively calcify,
culminating in a “Ground Glass” or
Mottled Mixed radiolucent/ radiopaque
pattern.
 Critical feature to diagnosis- FD fails
to manifest any discreate margins;
rather, the lesional bone subtly blends
into the surrounding normal appearing

18. Histopathology
 Early formative phase,
pronounced osteogenesis
is seen with thin osteoid
anastomosing trabeculae
that are rimmed with
osteoblast.
Stromal fibroblastic
element - proliferative and
hypercellular, no
pleomorphism.
With time, trabeculae
thicken and osseous
collagen pattern remain
woven and the trabeculae
assume the classic

19.  Long-standing polyostotic FD is
sarcomatous , which can occur in
absence of radiation therapy.
 Most frequent site - craniofacial
skeleton.
 Differentiating features on radiograph
between sarcoma and FD are:
◦ Permeative ill-defined borders,
◦ Destroyed cortical outline and/or spiculated
periosteal new bone formation
◦ Periodontal ligament space widening.

20. Malignant Transformation of
FD:
 Occur in <1% of the cases.
Osteosarcoma is the most common
histologic type, followed by
fibrosarcoma, chondrosarcoma, and
malignant fibrohistiocytoma.
Most common in the maxilla and
mandible
 Calvarium – rare involvement.
Spontaneous Conversion of Fibrous Dysplasia
Into Osteosarcoma(J Craniofac Surg 2011;22: 959 -961)

21. Treatment and Prognosis
 Timing of intervention is based on the
symptoms manifesting as a result of the
disease.
 Recommended treatment options can be
divided into 4 categories:
1. Observation
2. Medical therapy
3. Surgical remodelling
4. Radical excision and reconstruction

22. 1. Observation:
 Monitoring is through serial radiographs,
CT scans, and clinical examinations. In
lesions that present in childhood,
monitoring until skeletal maturity may
allow for ultimately less radical treatment
and less overall morbidity.
 Special attention to cranial nerve
function during monitoring of these
lesions should be exercised
 Decreased nerve function may be an
indication for surgical therapy.

23. 2. Medical treatment
Currently, no medical therapy exists for the
permanent cure of fibrous dysplasia.
1. Biphosphonates.
2. Systemic steroids

24. 3. Surgical Remodelling:
Chen YR, Noordhoff MS: Treatment of craniomaxillofacial fibrous
dysplasia: How early and how extensive? Plast Reconstr Surg 86:835, 1990

25. 4. Surgical Treatment
Indications:

Functional concern

Facial recontouring

Compression of the optic canal, recommended
decompression
Other indications for surgical therapy:

Cosmetic Deformity

Pain

Pathologic Fracture

Hearing Loss

Sinus Or Nasal Obstruction

Epistaxis

Malocclusion and Impeded mastication.

26. Osteitis Deformans( Paget
Disease)
 Rapid turnover remodeling of bone
throughout the skeleton.
 Disease of the elderly.
 Although two Paget-like bone
dysplasias that arise during childhood.

27. Etiology
 Defective function of the
osteoprotegerin/TNFRSF11A or
B/RANKL/RANK pathway, a molecular
regulator of osteoclastogenesis.

28. Classic Paget Disease of Bone
( CPDB)
 Late adult onset.
 Characterized by rapid turnover of bone
remodeling and osseous expansion with
progressive skeleton deformities.
 Tubular bones show bowing and spinal
curvature with vertebral collapse.
 Elevated serum alkaline phosphatase,
 Normal calcium and phosphorus levels.
 Cranial nerve neuropathies can develop
as a consequence of foramina
narrowing.
 Deafness

29. Radiographic Features
 In early stages, radiolucent “ Coin
shaped” lesions appear in the flat
bones of the skull, a condition called
as “ Osteitis Circumscripta”

30.  “Ground glass” trabecular pattern in
the early stage.
 “ Cotton wool” appearance in late
lesions
 Generalized hypercementosis

31. Histological Features
 Lesion shows marked evidence of
bone turnover.
 Resting and reversal lines of lamellar
compact and trabecular bone are
prevalent and haphazardly arranged
into a mosaic pattern.

32. Neoplastic Transformation
 Two neoplastic processes may occur
1. Giant cell tumors
2. Sarcomas( Osteogenic sarcoma,
fibrosarcoma, chondrosarcoma and
undifferentiated sarcoma)

33. Treatment
 Biphosphonates
 Histological appearance also appear
more normal after drug therapy.

34. Juvenile Paget Disease
(Idiopathic Hyperphosphatasia)
 Inherited as an autosomal recessive
trait
 Deformities in the long bones,
kyphosis, acetabular protrusion and
pathophysiologically by rapid turnover.
 Long bone widening with pathologic
fracture and thickening of skull.
 Elevated serum alkaline phosphatase
 Osteopenia and skeletal deformity
with bowed limbs

35. Familial Expansile Osteolysis(
FEO)
 Autosomal dominant trait
 Manifest in the second decade
 Osteoclastic resorption with cancellous
bone expansion and elevated serum
alkaline phosphatase.
 Early tooth loss by external resorption
 Deafness
 Histologically - focal collection of
multinucleated giant cells and viral-like
inclusions.

36. Expansile Skeletal
Hyperphosphatasia(ESH)
 Autosomal dominant trait
 Accelerated bone turnover with
hyperostotic expansion of the long bones
 Pain in phalanges
 Premature tooth exfoliation and deafness
 Episodic hypercalcemia
 Absence of large osteolytic lesions with
cortical thinning.
 Elevated alkaline phosphatase.
 No viral like inclusions.

37. Segmental Odontomaxillary
Dysplasia
 Lesion confined to a single segment of
the maxilla, usually in premolar and
molar.
 Clinical Features:
◦ Teeth fail to erupt
◦ Dental anomalies like- malformed, mis
shapened and/ or teeth of anomalous
size.
 Expansion of alveolar bone

38. Radiographic Features
 Falling Sheet pattern

39. Histological Features
 Minimal osteoblastic rimming and the
fibrous element is represented by
small immature collagen with mild
increase in cellularity.

40. Cemento-Osseus Dysplasia
 These conditions are defined by
specific clinical and pathological
features and have been classified as
Cemento-Osseus Dysplasia
 Periapical Cemental Dysplasia
 Focal Cemento-Osseus Dysplasia
 Florid Osseous Dysplasia

41.  Precise etiology is unknown.
 Disorders of metabolism of cells
normally involved in production of
bone and cementum matrices.
 The aberrant activity of the tissues
may be the result of an unusual
response to undefined local factors.

42. Periapical Cemental Dysplasia
 Seen at the apices of the teeth with vital , non-inflamed
pulps.
 Predominantly involves mandibular incisors.
 Usually detected incidentally on routine
radiographic examination.
Radiographic Examination
 Consist of multiple round to ovoid , radiolucent
lesions at the apex of the vital teeth.
 May mimic periapical pathology of pulpal origin.
 Individual lesions are seldom more than 1.0 cm in
diameter and most are less than 0.5 cm in size.
 The radiolucences maybe discrete with well
defined borders or they maybe large enough to
appear confluent as they overlap and merge.

43. Histopathology
 On Biopsy, they consist of multiple
fragments of moderately cellular,
collagenous tissue.
 Amount and degree of mineralization
component are variable, dependent on the
length of time the lesions present and
therefore the stage of the process.
 The calcified tissue is associated with
osteoblasts and the cementoblasts along
the surface and is deposited in a variety of
configurations.
 Inflammatory cells are present

44. Focal Cemento-Osseus
Dysplasia
Clinical Features :
 Female predominance.
 4th -5th decades of life.
 Solitary lesions , in posterior mandible.

45. Radiographic Features
 Diagnosed in routine radiographs,
characteristically, asymptomatic.
 Most lesions appear as radiolucent – radio-opaque
areas.
 In edentulous areas development of
idiopathic bone cavities, result in bony
expansion of affected area.

46. Histopathology
 Consistency of tissue
removed for biopsies is
important .
 Difficult to curette form
the sockets, is removed
as multiple fragments of
gritty tissues
 Distinction between
ossifying fibroma, which
typically can be
removed as large
fragmented that can be
separated cavity form
bone.
“Ginger root” Pattern

47. Treatment
 Lesions exhibit only limited potential
for progressive growth, more lesion
require no additional treatment
following biopsy.
 Periodic observation

48. Florid Cemento-Osseous
Dysplasia
 Middle-aged females
 Painless non-expansile lesion often
involving two or more jaw quadrants.
 Radiographically - multiple confluent
lobular radiopaque masses in tooth-bearing
areas
 Tendency toward bilateral,
symmetrical involvement
 Asymptomatic and detected incidentally

49.  Jaw expansion - large lesions.
 Dull pain or drainage are always
associated with exposure of the
sclerotic calcified masses to the oral
cavity as the result of progressive
alveolar atrophy under a denture or
after extraction of teeth in the involved
area.

51. Treatment
 Often difficult, not very satisfactory.
 In the asymptomatic patient
observation
 Antibiotics
 Sequestration of the cementum-like
masses will occur slowly and followed
by healing.
 Saucerization or surgical excision

52. Inflammatory/ Reactive
Processes
 This include:
◦ Focal Sclerosing Osteomyelitis(
Condensing Osteitis)
◦ Diffuse Sclerosing Osteomyelitis
◦ Proliferative Periostitis

53. Focal Sclerosing Osteomyelitis
( Condensing Osteitis)
 Mildest and most self-limiting form
 Posterior mandible at apices of molar
teeth
 Bacterial origin
 Pathogenic bacteria are of low
virulence

54. Clinical Features
 Asymptomatic, nonexpansile
periapical lesion
 Early stages, radiolucency is
seen at the apex, simulating
a dental abscess, granuloma
or cyst.
 With time periapical
radiolucency opacifies.
 On histopathology no
inflammatory cells are seen.
 Treatment – Root canal
therapy

55. Differential Diagnosis
 Focal osteosclerosis
 Focal cemento osseous dysplasia

56. Diffuse Sclerosing
Osteomyelitis
 Unilateral diffuse ground glass
opacification without defined boundaries
of the mandibular body.
 Cortical expansion
 H/O dull episodic pain that last for weeks
to subside and later become
symptomatic again.
 Caused by gram negative anaerobic
bacteria of low virulence.
 Definitive anaerobic culture
 Source of infection - Odontogenic

58.  Microscopically, bone exhibits a fibro
osseous pattern with intervening foci
of dense sclerotic bone.
 Osseous elements are trabecular
 Cementifying areas - absent.

59. Differential diagnosis
Lesion Clinical Features Histological
Features
Fibrous Dysplasia Painless lesion Chinese figure
pattern
Florid cememto
osseous dysplasia
Multiquadrant
opaque lesions with
associated
radiolucencies
Show both
trabecular and
cementifying areas
along with hollow
bone cavities

60. Proliferative Periostitis
 Low grade infections
progress of DSO involves
periosteoum.
 Induces neo-osteogenesis
and periosteal layer becomes
redundant, yielding classic
“onion skinning”
phenomenon.
 Histologically, periosteum
discloses a trabecular pattern
that is often reteform with a
tendency for parallel
orientation

61. Treatment
 Removing odontogenic infection
source by extraction or RCT.
 Long term antibiotic therapy.

62. Hyperparathyroidism
 The “brown tumor” of
hyperparathyroidism, a giant cell
lesion, may be encountered anywhere
in the skeleton in both primary and
secondary HPT.
 Reported among patients with renal
osteodystrophy.

63. Clinical Features
 Marked facial deformity
 Thickening of dipole and massive
maxillomandibular enlargement with
protrusion of anterior teeth and wide
diastemas.
 Also known as – Sagliker Syndrome
and the Uglifying Human Face
Syndrome.
 Histologically, trabecular pattern is
seen

64.  Enlarged regions of facial bones, jaws
and skull manifest a dense ground
glass opacification.
 Parathyroidectomy does not result in
resolution of the bony enlargements.

65. Ossifying Fibromas
 Neoplasms with a fibro-osseous
histology represented by the ossifying
fibroma group of lesions.
 Neoplasms in the true sense
exhibiting progressive proliferative
capabilities with bony expansion and
well defined margins radiologically.

66. Types
 Ossifying/ Cementifying Fibroma
 Juvenile Ossifying Fibroma
 Trabecular Juvenile Ossifying Fibroma
 Psammomatoid Juvenile Ossifying
Fibroma
 Gigantiform Cementoma

67. Ossifying/Cementifying
Fibroma
 Most common form of OF occurs in
maxilla and mandible.
 Mutation in HRPT2 gene that encodes
parafibromin protein.
 Painless with expansion of both cortices.
 Larger lesions may expand the inferior
aspect of mandible.
 Teeth are displaced superiorly (
mandibular lesion) and inferiorly(
maxillary lesion) and expand into the
antrum.

68. Radiographic Features
 Early lesions appears radiolucent
 With time it appears radiopaque, as
more matrix calcifies.

69. Histological Features
 Shows three
histological forms
◦ Ossifying
◦ Cementifying
◦ Storiform

70. Juvenile Ossifying Fibroma
 Also known as Juvenile Active
Ossifying Fibroma and Juvenile
Aggressive Ossifying Fibroma.
 2 clinicopathologic entities
1. Trabecular Juvenile Ossifying Fibroma
( TrJOF)
2. Psammomatoid Juvenile Ossifying
Fibroma (PsJOF)

71. Trabecular Juvenile Ossifying
Fibroma(TrJOF)
 Also known as trabecular desmo-osteoblastoma.
 Majority of patients are children and
adolescents.
 Only 20% are over 15 years of age.
 M:F = 1:1
 Maxilla and mandible are dominant
sites.
 Maxilla is slightly more affected.

72. Clinical Features
 Progressive and sometimes rapid
expansion of bone
 In maxilla, obstruction of nasal
passages and epistaxis may be
present.

73. Radiographic Features
 Expansive and well
demarcated
 With cortical thinning
and perforation
 Shows varying
amount of
radiolucency and
opacity depending
upon amount of
calcified tissue.
 Ground glass and
honeycomb
appearance.

74. Histological Features
 Uncapsulated and shows
infiltration of surrounding
bone
 Characteristic loose
structure
 Stroma is cell rich, with
spindle or polyhedral
cells, produce little
collagen
 Cellular, immature
osteoid forms strands.
 Irregular mineralization
takes place at the centre
of the strands
 Local aggregates of
osetoclastic giant cells
are invariably present in
the stroma.

75.  Clinical course is characterized by
infrequent recurrence following
conservative excision.
 Complete cure could be achieved in
those cases without resorting to
radical surgical intervention.
 Malignant transformation not reported

76. Psammomatoid Juvenile
Ossifying Fibroma
 Affects extragnathic craniofacial
bones, particularly periorbital, frontal
and ethmoid bones.
 Gogl,1949, as psammomatoid fibroma
of the nose and paranasal sinuses.
 Margo,1985 described as a distinctive
solitary fibro-osseous lesion that
affects the orbit and shows distinctive
histologic features.

77.  16 to 33 years.
 Range of 3 months to 72 years.
 Majority originates in paranasal
sinuses ( frontal and ethmoid).
 10 % in calvarium
 7% in mandible( Makek in 1983)

78. Clinical Features
 Bone expansion involves orbital or
nasal bones and sinuses.
 Orbital extension- proptosis and visual
complaints including blindness, nasal
obstruction, ptosis, papilledema and
disturbances in ocular mobility.

79. Radiographic Features
 Round, well defined,
corticated osteolytic
lesion with a cystic
appearance.
 In CT scans, appear less
dense than normal bone,
appear multiloculated
 Size range from 2 to 8
cm
 In facial skeleton a well
circumscribed expansive
mass with a thick wall of
bone density on CT scan
is strongly suggestive of
psammomatoid juvenile

80. HISTOPATHOLOGY
 On gross examination tumor is yellowish, white
and gritty.
 Histologically, multiple round uniform small
ossicles (psammomatoid bodies) embedded in
a cellular stroma composed of uniform,
stellate, and spindle shaped cells.
 Psammomatoid bodies are basophilic and bear
superficial resemblance to dental cementum,
but may have an osteoid rim.

81.  Surgical excision is treatment of
choice.
 Recurrence rate of >30% reported.
 No malignant change observed.

82. Familial Gigantiform
Cementoma
 An autosomal dominant variant
usually involving multiple quadrants
with variably expansile lesions.
 Anterior mandible.
 No racial predilection.
 Often evolve during childhood and
can grow rapidly.

83.  Radiographically,
expansion with a
radiolucent mass
containing
floccular
calcifications.
 Microscopically,
benign
hypercellular
stroma with
monomorphic
appearing
fibroblasts and
mature collagen
fibers.
 Ovoid, laminated,
psammomatoid
calcifications are

84.  Treatment is resection with immediate
or staged reconstruction.