The document defines fibro-osseous lesions and Waldron's classification system. It describes fibrous dysplasia as a benign fibro-osseous condition involving bone replacement by fibrous tissue. Fibrous dysplasia can present as monostotic (single bone) or polyostotic (multiple bones) forms. The polyostotic form is associated with skin pigmentation and endocrine abnormalities in Albright's syndrome and McCune-Albright syndrome.

2. DEFINITION
 Waldron in 1970 described fibro- osseous
lesions as a group of pathological changes
within the jaw – bones in which normal
bone is replaced by fibrous tissue, with or
without calcification.

3. FIBRO-OSSEOUS LESIONS
 Non – neoplastic or neoplastic, and of
 Odontogenic or non – odontogenic
origin.
 Includes
 Developmental (hamartomatous)
lesions,
 Reactive or dysplastic processes, &
 Neoplasms

4. WALDRON
CLASSIFICATION
I. Fibrous dysplasia
- Polyostotic
- Monostotic
-Craniofacial form
-Cherubism
II. Reactive (dysplastic) lesions in the tooth –
bearing area, presumably of PDL origin
-Periapical cemento- osseous dysplasia
-Focal cemento – osseous dysplasia
-Florid cemento – osseous dysplasia
III. Fibro –osseous neoplasms
- Cemento – ossifying fibroma

5. FIBROUS DYSPLASIA
 Benign
 Developmental tumor like condition
 Skeletal developmental anomaly of the
bone – forming mesenchyme that
manifests as a defect in osteoblastic
differentiation and maturation.
 Characterised by replacement of normal
bone by an excessive proliferation of
cellular fibrous connective tissue
intermixed with irregular bony trabeculae

6. FIBROUS DYSPLASIA
 Definition – Edwards 1984
 A benign fibro - osseous condition
involving one or more bones of the
cranial and extracranial skeleton,
consists of non-encapsulated lesions
which show replacement of the normal
bone by cellular fibrous tissue containing
islands of metastatic bone.
 Classified by WHO as developmental in
origin

7. FIBROUS DYSPLASIA -
ETIOLOGY
 Exact cause – not known
 Not hereditary
 Sporadic condition that results from a
postzygotic mutation in the GNAS1
gene(20q13.2)
 GNAS1 gene guanine nucleotide –
binding protein, α – stimulating activity
polypeptide 1 gene

8. FIBROUS DYSPLASIA -
ETIOLOGY
 Clinically, fibrous dysplasia may
manifest as a localised process
involving only one bone, as a condition
involving multiple bones, or as multiple
bone lesions in conjunction with
cutaneous and endocrine abnormalities.
 Clinical severity depends on point in
time during fetal or postnatal life that the
mutation of GNAS1 occurs

9. FIBROUS DYSPLASIA -
ETIOLOGY
 If mutation occurs in one of
undifferentiated stem cells during early
embryologic life,
 the osteoblasts, melanocytes and
endocrine cells that represent the
progeny of that mutated cell all will carry
that mutation and express that mutated
gene
multiple bone lesions, cutaneous
pigmentation, and endocrine
disturbances

10. Osteoblasts
• Multiple bone
lesions
Melanocytes
• Cutaneous
pigmentations
Endocrine
cells
• Endocrine
disturbances

11. FIBROUS DYSPLASIA -
ETIOLOGY
 Skeletal progenitor cells at later stages
of embryonic development are
assumed to migrate and differentiate as
part of process of normal skeletal
formation.
 Mutation during this later period 
progeny of mutated cell will disperse
and participate in formation of skeleton
 multiple bone lesions of FD

12. FIBROUS DYSPLASIA -
ETIOLOGY
 If mutation occurs during post natal life
 progeny of mutated cell confined to
one site  FD affecting a single bone.

13. FIBROUS DYSPLASIA -
ETIOLOGY
 GNAS 1 gene encodes a G –protein
that stimulates the production of cAMP.
 Mutation results in continous activation
of G – protein leading to over production
of cAMP in affected tissues.
 Results in a hyperfunction of affected
endocrine organs, frequently giving rise
to precocious puberty, hyperthyroidism,
growth hormone and cortisol
overproduction

14. FIBROUS DYSPLASIA -
ETIOLOGY
 Secondly  increased proliferation of
melanocytes resulting in large
café–au-lait spots with irregular
margins(regular outlined café-au-lait
spots in neurofibromatosis).
 Thirdly , cAMP is thought to have an
effect on differentiation of osteoblasts
leading to fibrous dysplasia.

15. FIBROUS DYSPLASIA -
ETIOLOGY
 In fibrous dysplasia, medullary bone is
replaced by fibrous tissue, which
appears radiolucent on radiographs,
with classically described ground-glass
appearance.
 Trabeculae of woven bone contain fluid -
filled cysts that are embedded largely in
collagenous fibrous matrix, contributes
to generalised hazy appearance of the
bone.

16. FIBROUS DYSPLASIA
CLINICAL PATTERNS
 Four clinical types of this disease:
1. Monostotic form involving only one
bone
2. Polyostotic forms involving many bones
which can be subclassified as:
1. Jaffe’s type – several bones of skeleton
involved

17. FIBROUS DYSPLASIA
CLINICAL PATTERNS
2. Albrights syndrome , a polyostotic form
accompanied by pigmented skin lesions,
endocrine dysfunction presenting as
precocious puberty in females, and
sometimes other anomalies(Albright et
al.1937);
3. Craniofacial form confined to bones of
the craniofacial complex. A case of
polyostotic dysplasia has been described
in association with dentinal
dysplasia(Wannfor’s et al. 1985).

18. FIBROUS DYSPLASIA
CLINICAL PATTERNS
4. Cherubism - Special variant of FD
An autosomal – dominant disorder of
variable penetrance.

19. MONOSTOTIC FIBROUS
DYSPLASIA
 Disease limited to single bone.
 Appx. 70 – 80% of FD  monostotic
 Most frequently occurs in
Rib – 28%
Femur – 23%
Tibia
Craniofacial bones -10-25%
 & Humerus in decreasing order of
frequency

20. MONOSTOTIC FIBROUS
DYSPLASIA
 Postnatal mutation of GNAS 1 – may
occur during infancy, childhood or
adulthood.
 Most monostotic form diagnosed during
second decade of life
 Male = Female
 Maxilla > Mandible
 Mandibular lesion – truly monostotic

21. MONOSTOTIC FIBROUS
DYSPLASIA
 Maxillary lesions often involve adjacent
bones(e.g. zygoma, sphenoid , occipital)
not strictly monostotic
Craniofacial fibrous dysplasia.
 FIRST CLINICAL SIGN – Painless
swelling or bulging of jaw.
 Pt may present with pain or pathologic
fracture in pts aged 10 – 70 yrs.
 Degree of bone deformity less severe
compared to polyostotic type

23. MONOSTOTIC FIBROUS
DYSPLASIA
 Growth – generally slow, occasionally
rapid.
 Teeth involved in lesion – usually firm
but may be displaced by the bony mass.
 Swelling usually involves labial or
buccal plate
 Outer surface – eggshell- thin cortex of
expanded bone.
 Seldom lingual aspect

24. MONOSTOTIC FIBROUS
DYSPLASIA
 In mandible – protuberant excrescence
(bulging) of lower border.
 Superior displacement of inferior
alveolar canal.
 Malalignment, tipping or displacement of
the teeth due to the progressive
expansile nature of lesion.
 Tenderness may ultimately develop.
 Mucosa intact over lesion

25. MONOSTOTIC FIBROUS
DYSPLASIA
 FD of maxilla – serious form of disease
 Marked predilection – in children
 Almost impossible to eradicate without
radical,mutilating surgery.
 Lesion – not well circumscribed
 Commonly extend locally to involve the
 maxillary sinus,
 the zygomatic process & floor of orbit,
 & even extend back toward the base of
skull

26. MONOSTOTIC FIBROUS
DYSPLASIA
 Severe malocclusion
 Bulging of canine fossa
 Extreme prominence of zygomatic
process
 marked facial deformity, are typical
sequelae of this disease in this location
need not be truly monostotic , but
neither be usually classified as
polyostotic type.
 Referred to as craniofacial FD

27. MONOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 Extremely variable.
 Three basic patterns seen.
1. Small unilocular radiolucency or
somewhat larger multilocular
radiolucency, both with a rather well
circumscribed border and containing a
network of fine bony trabeculae.

29. MONOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
2.Similar pattern except that increased
trabeculation renders the lesion more
opaque & typically mottled in
appearance.
3.Opaque with many delicate trabeculae
gives a “ ground glass” or “ peau
d’orange” appearance to the lesion.
- not well circumsribed but instead
blends into the adjacent normal bone.

31. MONOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 Any of 3 types in either Mx or Md
 In all types , generally cortical bone
becomes thinned because of the
expansile nature of the growth, but
seldom is this bony plate perforated, or
is periosteal proliferation obvious.
 Roots of teeth in involved areas may be
separated or moved out of normal
position but only occassionally exhibit
severe resorption

32. MONOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 Some cases – bone appears so opaque
that the roots of teeth may be indistinct
or not visible.
 In craniofacial fibrous dysplasia , there is
characteristic radiographic thickening of
the base of the skull.

33. MONOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Fibrous lesion made up of proliferating
fibroblasts in a compact stroma of
interlacing collagen fibers.
 Irregular trabeculae of bone scattered
throughout the lesion – no definite
pattern of arrangement.
 Characteristically  trabeculae are C –
shaped, or Chinese character – shaped.

35. MONOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Trabeculae – usually coarse woven
bone but may be lamellar, not as well
organised as normal lamellar bone.
 Large lesions – greater bony reaction
around the periphery of the lesion than
in the central portion.

36. MONOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Earlier literature – represents permanent
maturation arrest in woven bone stage &
 lesions demonstrating lamellar
transformation - not be diagnosed as
fibrous dysplasia.
 However, on basis of work of Waldron &
Giansanti, that lesions of FD of the jaws,
esp . Craniofacial type, will mature over
a period of time & lesional tissue may
show lamellar bone.

37. POLYOSTOTIC FIBROUS
DYSPLASIA
 20 – 30% of FD
 Frequently involves the
 skull and facial bones,
 pelvis,
 spine, and
 shoulder girdle.

38.  Sites of involvement –
 Femur,
 Tibia
 Pelvis
 Ribs
 Skull & facial bones
 Upper extremities
 Lumbar spine
 Clavicle
 & cervical spine
in decreasing order of frequency

39. POLYOSTOTIC FIBROUS
DYSPLASIA
 Unilateral or bilateral
 May affect several bones of a single
limb or both limbs with or without axial
skeleton involvement.
 Tends to occur in a unilateral
distribution.
 When disease is bilateral - involvement
is asymmetric & generalised.

40. POLYOSTOTIC FIBROUS
DYSPLASIA
 Two – thirds of patients – symptomatic
before the age of 10.
 Initial symptom – pain in involved limb
associated with a limp, spontaneous
fracture or both
 Leg – length discrepency  70% pts
with limb involvement.
 Structural integrity of bone is weakened
 Weight bearing bones become bowed

41. POLYOSTOTIC FIBROUS
DYSPLASIA
 Curvature of the femoral neck and
proximal shaft of the femur markedly
increase causing a shepherd’s crook
deformity(hockey stick deformity) –
characteristic sign of the disease.
 Overgrowth of adjacent soft tissues –
may be present.

42. POLYOSTOTIC FIBROUS
DYSPLASIA
 Two types
 Jaffe’s type – involves a variable number
of bones, although most of skeleton is
normal, accompanied by pigmented
lesions of the skin or “ café-au-lait”
(coffee with milk) spots.
 Albright’s syndrome – more severe FD
involving nearly all bones in skeleton &
accompanied by pigmented lesions of
the skin, & endocrine disturbances.

43. POLYOSTOTIC FIBROUS
DYSPLASIA
 Another rare disorder associated with
FD is Mazabraud syndrome,
characterised by FD in combination with
intra muscular myxomas.

44. POLYOSTOTIC FIBROUS
DYSPLASIA
JAFFE-LICHTENSTEIN
SYNDROME
 FD with cutaneous pigmentation ( café-
au-lait spots).
 Cutaneous pigmentation – most
common extraskeletal manifestation in
FD.
 Occurs in more than 50% of cases of
PFD.
 Related to increased amounts of
melanin in the basal cells of the
epidermis.

46. POLYOSTOTIC FIBROUS DYSPLASIA
JAFFE-LICHTENSTEIN
SYNDROME
 Café-au-lait pigmentation
 well defined,
 unilateral tan macules
 on the trunk & the thighs.
 Ipsilateral to the side of bony lesions , a
feature that differentiates this disease
from pigmentation in neurofibromatosis.

47. POLYOSTOTIC FIBROUS DYSPLASIA
JAFFE-LICHTENSTEIN SYNDROME
 May be congenital, & pigmented oral
mucosal macules also may be present.
 Occassionally precede the development
of skeletal & endocrine abnormalities.
Café-au-lait spots Margins Resembles map of the
Fibrous dysplasia Very irregular Coast-line of Maine
Neurofibromatosis Smooth borders Coast of California

48. POLYOSTOTIC FIBROUS DYSPLASIA
JAFFE-LICHTENSTEIN SYNDROME
 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, &
Shoulders.
May occur on the Lips & oral mucosa

49. POLYOSTOTIC FIBROUS DYSPLASIA
McCUNE-ALBRIGHT SYNDROME
 McCune –Albright syndrome or
polyostotic fibrous dysplasia(PFD) is
defined as the association of polyostotic
fibrous dysplasia, precocious puberty,
café-au-lait spots, & other
endocrinopathies due to hyperactivity of
various endocrine glands.
 Fuller Albright first described this
syndrome in 1937

50. POLYOSTOTIC FIBROUS DYSPLASIA
McCUNE-ALBRIGHT SYNDROME
 Postzygotic activating mutation of the
GS alpha gene in the affected tissues.
 GS alpha subunit - component of the G
– protein complex
 Couples hormone receptors to
adenylate cyclase (the intracellular
second messenger) in a submembrane
site.
 Then mediates the cellular effects of
hormone binding.

51. POLYOSTOTIC FIBROUS DYSPLASIA
McCUNE-ALBRIGHT SYNDROME
 Precocious puberty – most common
endocrine manifestation , particularly in
females.
 Menstrual bleeding in first few months.
 Breast development & pubic hair within
first few years of life in affected girls.
 Gonadotrophin independent.

52. POLYOSTOTIC FIBROUS DYSPLASIA
McCUNE-ALBRIGHT SYNDROME
 Endocrine disturbances associated with
this syndrome are
 Hyperthyroidism
 Pituitary adenoma
 Acromegaly
 Gonadotrophin-McCune-Albright
syndrome
 Hyperprolactinemia

53. POLYOSTOTIC FIBROUS DYSPLASIA
McCUNE-ALBRIGHT SYNDROME
 Cushing syndrome
 Hyperparathyroidism
 Hypophosphatemic rickets
 Some severely affected pts may present
with associated
Hepatic,
Cardiac, &
GI dysfunction(i.e. elevated hepatic
transaminases , GI polyposis , &
cardiomyopathy)

54. POLYOSTOTIC FIBROUS
DYSPLASIA
MAZABRAUD’S SYNDROME
 Association of fibrous dysplasia &
intramuscular myxoma.
 Both lesions tend to occur in same
anatomical region.
 Relationship – unclear, whereas an
underlying localised error in tissue
metabolism has been proposed to
explain this occasional coexistence

55. POLYOSTOTIC FIBROUS
DYSPLASIA
MAZABRAUD’S SYNDROME
 Pts with soft tissue myxomas should be
thoroughly examined for FD.
 Greater risk of sarcomatous
transformation in FD with Mazabraud’s
syndrome has been reported.

56. POLYOSTOTIC FIBROUS
DYSPLASIA
 Malignancy occur most commonly in the
setting of therapeutic irradiation
exposure.
 Females – greater risk for breast cancer,
probably due to their prolonged
exposure to elevated estrogen levels.
 Increased risk of thyroid & secondary
osseous malignancies.

57. POLYOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 In long & short tubular bones
 Lucent lesion in the diaphysis or
metaphysis, with endosteal scalloping
 With or without bone expansion
 Absence of periosteal reaction.
 Lucent lesion has a thick sclerotic
border  rind sign

58. POLYOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 Among skull & facial bones
 Frontal bone is involved more frequently
than the sphenoid
 With obliteration of the sphenoid &
frontal sinuses
 Single or multiple
 Symmetric or asymmetric
 Radiolucent or sclerotic lesions in skull
or facial bones may be present

59. CT SHOWING
INVOLVEMENT OF
MAXILLA & SKULL

60. POLYOSTOTIC FIBROUS
DYSPLASIA
RADIOGRAPHIC FEATURES
 Radiolucent or sclerotic lesions in skull
or facial bones may be present.
 Most commonly, maxillary & mandibular
involvement has a
 mixed radiolucent & radiopaque pattern,
 With displacement of the teeth &
 Distortion of nasal cavities.

61. POLYOSTOTIC FIBROUS
DYSPLASIA
ORAL MANIFESTATIONS
 Expansion & deformity of the jaws.
 Eruption pattern of teeth disturbed
because of loss of normal support of the
developing teeth.
 Endocrine disturbance also may alter
the time of eruption of the teeth
( McCune Albright syndrome).

62. POLYOSTOTIC FIBROUS
DYSPLASIA
LABORATORY FINDINGS
 No significant changes in the serum
calcium or phosphorus.
 Serum alkaline phosphatase level
sometimes elevated.
 Premature secretion of pituitary follicle-
stimulating hormone – reported.
 Moderately elevated basal metabolic
rate.

63. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Consists of irregularly shaped
trabeculae of coarse ,immature ( woven)
bone in a cellular, loosely arranged
fibrous stroma.
 Affected bone has areas of fibrous
metaplasia within flat & tubular bones.
 Basic anomaly is a progressively
expanding fibrous lesion of bone forming
mesenchyme.

64. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Lesions typically expand concentrically
from the medullary cavity outwards(i.e.
towards the cortex).
 Well defined, not encapsulated.
 Lesional bone fuses directly to normal
bone at the periphery of the lesion so
that no capsule or line of demarcatiopn
is present.

65. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Trabeculae – not connected to each
other
 Slender & arcuate or branched.
 Assume curvilinear shapes, likened to
chinese script writing
 Bone trabeculae – considered to arise
by metaplasia & are not surrounded by
plump appositional osteoblasts(i.e. no
osteoblastic rimming).

66. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Osteocytes are quite large ,
 & collagen fibres of these trabeculae
are seen extending out into the fibrous
tissue.
 Bone formation by stellate osteoblasts.
 Trabeculae have wide osteoid seams.
 Tiny calcified spherules –rarely seen
 Osteoclastic activity may be seen where
the calcification of osteoid extends to the
surface of the trabeculae.

67. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Lesions are rich in spindle shaped
fibroblasts, with a swirled appearance
within the marrow space and erratically
arranged ‘tongues’ of woven bone.
 Islands of cartilaginous tissue also
interspersed within the lesions.
 Some parts of affected bones may have
cystic lesions lined by multinucleated
giant cells akin to ostitis fibrosa cystica(
of severe hyperparathyroidism)but with
paucity of osteoblasts.

68. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 In contrast to Ossifying fibroma &
Cemento-osseous dysplasia,
 Fibrous dysplasia typically
demonstrates a rather monotonopus
pattern
 rather than being a haphazard mixture
of woven bone, lamellar bone, &
spheroid particles.

69. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 FD of long bones does not undergo
maturation
 Jaw & skull lesions tend to be more
ossified than their counterparts in the
rest of their skeleton.
 Particularly true in specimens from older
pts.

70. POLYOSTOTIC FIBROUS
DYSPLASIA
HISTOLOGIC FEATURES
 Serial biopsy specimens in some cases
have shown that histopathologically
 Classic FD of the jaws undergoes
progressive maturation to a lesion
consisting of lamellar bone in a
moderately cellular connective tissue
stroma.
 The bone lesions in these mature
lesions tend to run parallel to one
another.

71. POLYOSTOTIC FIBROUS
DYSPLASIA
TREATMENT & PROGNOSIS
 Smaller lesions – particularly Md
SURGICAL RESECTION in their
entirety without too much difficulty.
 Diffuse nature and large size of many
lesions , particularly those of Mx
preclude removal without extensive
surgery.
 Many cases disease tends to stabilize &
essentially stops enlarging when
skeletal maturation is reached.

72. POLYOSTOTIC FIBROUS
DYSPLASIA
TREATMENT & PROGNOSIS
 Some continue to grow(generally
slowly).
 Some pts with minimal cosmetic or
functional deformity may not require or
desire surgical treatment.
 Cosmetic deformity with associated
psychologic problems or functional
deformity in younger pts  surgical
reduction of lesion to an acceptable
contour without attempts to remove the
entire lesion.

73. POLYOSTOTIC FIBROUS
DYSPLASIA
TREATMENT & PROGNOSIS
 Cosmetic result – usually good –
regrowth occurs over time.
 25- 50% of pts show regrowth after
surgical shave-down of lesion.
 Regrowth more common in younger pts.
 Many surgeons believe that surgical
intervention should be delayed for as
long as possible.

74. POLYOSTOTIC FIBROUS
DYSPLASIA
TREATMENT & PROGNOSIS
 Few cases with primarily polyostotic
disease managed with bisphosphonate
therapy, such as intravenous
pamidronate & oral alendronate.
 Bisphosphanates provide pain relief &
improve skeletal strength.
 Malignant change –usually development
of osteosarcoma – rarely associated
with FD.

75. POLYOSTOTIC FIBROUS
DYSPLASIA
TREATMENT & PROGNOSIS
 Radiation therapy – Contraindicated .
 Risk for development of postirradiation
bone sarcoma.
 Pts with mazabraud syndrome - slightly
increased risk of sarcoma development ,
even in absence of radiation exposure.

76. CRANIOFACIAL FORM
 Occurs in 10 – 25% of pts with
monostotic form.
 50% with polyostotic form.
 Isolated cranoifacial form.
 Isolated variety – no extracranial lesions

77. CRANIOFACIAL FORM
 Sites of involvement most commonly
include
 Frontal
 Sphenoid
 Maxillary &
 Ethmoid bones.
 Occipital & temporal bones – less
commonly affected.

78. CRANIOFACIAL FORM
 Hypertelorism,
 Cranial asymmetry,
 Facial deformity,
 Visual impairment,
 Exophthalmos &
 Blindness may occur
 Involvement of orbital & periorbital
bones.

79. CRANIOFACIAL FORM
 Involvement of sphenoid wing &
temporal bones may result in
 Vestibular dysfunction,
 Tinnitus &
 Hearing loss
 Cribriform plates – involved
 Hyposmia or
 Anosmia may result.

80. CHERUBISM
 Familial fibrous dysplasia of jaws
 Disseminated juvenile fibrous dysplasia
 Familial multilocular cystic disease of
jaws.
 Familial fibrous swelling of jaws.

81. CHERUBISM
 Disease was first described in 1933 by
Jones, who called it familial multilocular
disease of the jaws.
 The term ‘ cherubism’ , was introduced
by Jones & others to describe the
clinical appearance of affected pts.
 According to WHO classification –
belongs to a group of non –neoplastic
bone lesions affecting only the jaws.

82. CHERUBISM
 Name cherubism - because the facial
appearance is similar to that of the
plump-cheeked little angels (cherubs)
depicted in Renaissance paintings.

83. CHERUBISM
 An autosomal dominant fibro-osseous
lesion of the jaws
 Involving more than one quadrant
 Stabilizes after the growth period,
usually leaving some facial deformity &
malocclusion.

84. CHERUBISM
 A non-neoplastic hereditary bone
lesion
 that is histologically similar to giant cell
granuloma,
 affects the jaws of children bilaterally
&symmetrically,
 usually producing the so –called
cherubic look.

85. CHERUBISM
 Rare benign condition with autosomal
dominant inheritance
 One of the very few genetically
determined osteoclastic lesions in the
human body.
 100% penetrance in males.
 Only 50 – 70 % penetrance in females.
 Great variation in clinical expression.

86. CHERUBISM
 Although hereditary – some cases 
no detectable family history.
 Although bilateral, also cases of
unilateral involvement – because of
incomplete penetrance or new
mutations.
 Some investigators believe that
cherubism arises from the mutation of a
nonsex-linked gene responsible for the
development of jaw bones.

87. CHERUBISM
 Gene related to cherubism located on
chromosome 4p16.3.
 Mutations subsequently were identified
in the SH3BP2 gene within this locus.
 Protein encoded by this gene is believed
 to function in signal transduction
pathways &
 to increase the activity of osteoclasts &
osteoblasts during normal tooth eruption

88. CHERUBISM
 Mutation in SH3BP2 gene may lead to
 Pathologic activation of osteoclasts &
 Disruption of jaw morphogenesis.
MUTATION IN
SH3BP2 GENE
ACTIVATION OF
OSTEOCLASTS CHERUBISM

89. CHERUBISM
 Typically, the jaw lesions of cherubism
remit spontaneously when affected
children reach puberty.
 Reduction in osteoclast formation
caused by sex steroids and the increase
in plasma concentrations of estradiol &
testosterone at puberty both suggest
 that the genetic defect responsible for
localised increase in osteoclast in
cherubism is overridden &

90. PUBERTY
Increased
synthesis
of sex
steroids
Increase in
plasma
concentration
of estradiol &
testosterone
REDUCTION IN
OSTEOCLAST FORMATION
CHERUBISM
REMISSION

91. CHERUBISM
CLINICAL FEATURES
 Affected Children are normal at birth
 Without clinically or radiographically
evident disease until 14 months to 3
years of age.
 At that time symmetric enlargement of
jaws begins.
 Typically earlier the lesion appears more
rapidly it progresses.

92. CHERUBISM
CLINICAL FEATURES
 Self- limited bone growth usually begins
to slow down when the pt reaches 5 yrs
of age
 Stops by the age of 12- 15 yrs.
 At puberty lesion begins to regress.
 Jaw remodelling continues through 3 rd
decade of life, at the end of which
clinical abnormality may be subtle.

93. CHERUBISM
CLINICAL FEATURES
 Signs & symptoms depend on severity
of the condition.
 Range from clinically or radiologically
undetectable features to
 grotesquely deforming mandibular &
maxillary overgrowth with respiratory
obstruction & impairment of vision &
hearing.

94. CHERUBISM
CLINICAL FEATURES
 Jaw lesions are usually painless &
symmetric & have florid maxillary
involvement.
 Cherublike facies arise from bilateral
involvement of the posterior mandible
that produces angelic chubby cheeks.
 ‘Eye to heaven’ or ‘ eyes upturned to
heaven’ appearance  a wide rim of
sclera visible beneath the iris

95. CHERUBISM
CLINICAL FEATURES
 Exposed sclera below iris – due to
involvement of the infraorbital rim and
orbital floor that tilts the eyeballs
upwards, as well as to stretching of the
upper facial skin that pulls the lower lid
downward.
 Lesions - firm & nontender

96. CHERUBISM
CLINICAL FEATURES
 Most commonly involve the molar to
coronoid regions, condyles always
spared
 Often associated with cervical
lymphadenopathy.
 Enlargement of cervical lymph nodes
contributes to pts full faced appearance
& is said to be caused by lymphoid
hyperplasia with fibrosis.

97. CHERUBISM
CLINICAL FEATURES
 Lymph nodes become enlarged before
the pt reaches 6 yrs of age,
 Decrease in size after age of 8 yrs &
 Rarely enlarged after age of 12 yrs.
 Intraoral swelling of alveolar ridges may
occur
 When maxillary ridge is involved, palate
assumes a V shape.

98. CHERUBISM
ORAL MANIFESTATIONS
 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.
 Transpositions & rotation of the teeth.

99. CHERUBISM
ORAL MANIFESTATIONS
 Severe cases  tooth resorption.
 In few cases, cherubism described has
being connected with other diseases &
conditions such as Noonan’s syndrome.
 Noonan’s syndrome – a lesion in the
humerus, gingival fibromatosis,
psychomotor retardation, orbital
involvement & obstructive sleep apnea.

100. CHERUBISM
ORAL MANIFESTATIONS
 Deciduous dentition may be shed
prematurely – as early as 3 yrs of age.
 Permanent dentition – often defective.
 Absence of numerous teeth &
displacement and lack of eruption of
those present.
 Oral mucosa intact & of normal color.

101. CHERUBISM
GRADING SYSTEM
 Arnott (1978) suggested the following
grading system for the lesions of
cherubism:
 Grade I – characterised by involvement
of both mandibular ascending rami
 Grade II – by involvement of both
maxillary tuberosities as well as
mandibular ascending rami

102. CHERUBISM
GRADING SYSTEM
 Grade III –by McCune-Albright
syndrome involvement of whole maxilla
& mandible except the coronoid process
& condyles.

103. CHERUBISM
RADIOGRAPHIC
FEATURES
 Bilateral multilocular cystic expansion of
the jaws.
 Early lesions – occur in posterior body of
mandible & ascending rami.
 Maxillary lesions may occur at same
time but escape early radiographic
detection because of overlap of sinus &
nasal cavities.

104. CHERUBISM
RADIOGRAPHIC
FEATURES
 Displacement of inferior alveolar canal –
reported.
 Presence of numerous unerupted teeth
& destruction of alveolar bone may
displace the teeth, producing a
radiographic appearance referred to as
floating tooth syndrome.

106. CHERUBISM
RADIOGRAPHIC
FEATURES
 With adulthood, cystic areas in jaws
become re-ossified – results in irregular
patchy sclerosis.
 There is a classic( but nonspecific)
ground glass appearance because of
small, tightly compressed trabecular
pattern.

107. CHERUBISM
HISTOLOGIC FEATURES
 Numerous multinucleated giant cells.
 Multinucleated cells show strong
positivity for tartrate-resistant acid
phosphatase – characteristic of
osteoclasts.
 Collagenous stroma – contains a large
number of spindle shaped fibroblasts, is
considered unique because of its water-
logged, granular nature.

108. CHERUBISM
HISTOLOGIC FEATURES
 Numerous small vessels – present.
 Capillaries exhibit large endothelial cells
& perivascular cuffing.
 Eosinophilic cuffing – specific to
cherubism, not presnt in many cases –
doesn’t exclude disease.
 Older, resolving lesions- increase in
fibrous tissue, decrease in no. of giant
cells & formation of new bone.

109. CHERUBISM
DIFFERENTIAL
DIAGNOSIS
 Microscopic finding seldom permit a
specific diagnosis of cherubism in the
absence of clinical & radiological
information.
 DD: - Giant cell granuloma of jaws
-Osteoclastoma
-Aneurysmal bone cyst
-Fibrous dysplasia
-Hyperparathyroidism.

110. CHERUBISM
TREATMENT
 Laskin (1985) stated that “ the treatment
of cherubism should be based on the
known natural course of the disease and
the clinical behaviour of the individual
case”
 Surgery – rarely indicated.
 If necessary , surgery is usually
undertaken after puberty, unless esthetic
considerations or severe functional
problems justify earlier treatment.

111.  Exacerbation – reported after surgery
 It is believed that surgery ultimately
accelarates the involution process.
 Excellent results obtained in some
cases by early surgical intervention with
curettage of the lesions.
 Conversly early surgical intervention
sometimes followed by rapid regrowth
of the lesions & worsening deformity.

112.  A course limited only to observation may
result in extreme & sometimes
grotesque facial deformity with
associated psychologic problems &
functional deformity that may
necessitate extensive surgery..
 Use of calcitonin in severe cases –
suggested.
 Radiation – contraindicated  risk of
development of postirradiation sarcoma

113. CEMENTO-OSSEOUS
DYSPLASIA
 Occurs in the tooth bearing areas of the
jaws .
 Most common fibro-osseous lesion
encountered in clinical practice.
 ORIGIN:
 Arises in close approximation to the PDL
& exhibits histopathologic similarities
with the structure. PDL origin.

114.  Some believe that it represents a defect
in extraligamentary bone remodelling
that may be triggered by local factors &
possibly correlated to an underlying
hormonal imbalance.

115. CLASSIFICATION
 Based on clinical and radiographic
features divided into three groups
 FOCAL
 PERIAPICAL &
 FLORID
 Represent variants of the same
pathologic process.

116. FOCAL CEMENTO-OSSEOUS
DYSPLASIA
 Single site of involvement
 90% in females.
 Mean age – 38 years.
 Predilection for the third to sixth
decades.
 White predilection.
 May occur in any area of the jaws.
 Posterior mandible predominant site.

117.  Asymptomatic & detected only on a
radiographic examination.
 Most lesions –smaller than 1.5 cm in
diameter.
 RADIOGRAPH :
 Varies from completely radiolucent to
densely radioopaque with a thin
peripheral radiolucent rim.

118.  Mixed radiolucent & radiopaque pattern.
 Lesion tends to be well defined, but the
borders are usually slightly irregular.

119.  Occurs in dentulous & edentulous areas,
with many examples in extraction sites.
 Occasionally, an apparently focal lesion
may represent an early stage in the
transition to multifocal involvement.

120. PERIAPICAL CEMENTO-
OSSEOUS DYSPLASIA
 Other names:
 Osseous dysplasia
 Cemental dysplasia
 Cementomas.
 Predominantly involves the periapical
region of the anterior mandible.
 Solitary lesions may occur, but multiple
foci are present more frequently.

121. PERIAPICAL CEMENTO-
OSSEOUS DYSPLASIA
 Predilection for female patients.
 70% cases affects blacks
 Diagnosed initially between ages of 30 &
40, but neverin individuals younger than
age 20
 Associated teeth – invariably vital &
seldom have restorations.
 Asymptomatic discovered during routine
radiographs.

122.  Early lesions appear as circumscribed
areas of radiolucency involving the
apical area of a tooth.
 At this stage DD – Periapical granuloma
or periapical cyst.

123.  With time, adjacent lesions often fuse to
form a linear pattern of radiolucency that
envelops the apices of several teeth

124.  Serial radiographic studies reveal that
the lesions tend to “mature” over time to
create a mixed radiolucent and
radiopaque appearance.
 In end stage, lesions show a
circumscribed dense
calcification surrounded by a
narrow radiolucent rim.
 However PDL is intact, &
fusion to the tooth is not seen.

125.  Individual lesions seldom exceed 1.0 cm
in diameter.
 Each lesion is self-limiting & does not
typically expand the cortex.
 Progressive growth seldom, if ever ,
occurs.

126. FLORID CEMENTO-OSSEOUS
DYSPLASIA
 Appears with multifocal involvement not
limited to the anterior mandible.
 Many cases demonstrate multifocal
lesions only in the posterior portions of
the jaws, many pts also reveal
synchronous involvement of the anterior
mandible.
 Predominantly involves black women.

127.  Marked predilection for middle-aged to
older adults.
 Lesions show a marked tendency for
bilateral & often quite symmetrical
involvement.
 Not unusual to encounter extensive
lesions in all four posterior quadrants.

128.  Completely asymptomatic & discovered
only when radiographs are taken for
some other purpose.
 May complain of dull pain, and an
alveolar sinus tract may be present,
exposing yellowish, avascular bone to
the oral cavity.
 Rarely prominent- some degree of
expansion noted in one or more of the
involved areas.

129.  Radiograph – demonstrate an identical
pattern of maturation noted in other two
forms.
 Initially, lesions are predominantly
radiolucent but with time become mixed,
then predominantly radiopaque with only
a thin peripheral radiolucent rim.
 Occasionally totally radiopaque & blend
with adjacent normal appearing bone.

130.  Commonly radiopacities remain
separated from adjacent teeth with an
intervening intact periodontal ligament
space.
 Some cases- fusion of cemento-
osseous material directly on to the tooth
root surface may be observed in end-
stage lesions  result in thickened root
apices surrounded by radiolucency( or a
“hypercementosis- like” appearance)

131.  Both dentulous & edentulous areas may
be affected
 Involvement - unrelated to presence or
absence of teeth.
 More sharply defined radiolucent areas,
which on surgical exploration prove to
be simple bone cysts, may be
intermixed with other lesional elements.

132.  Cysts may be single or multiple.
 These simple bone cysts arise from
obstruction to drainage of normal
interstitial fluid by the fibro – osseous
proliferation.

133. HISTOPATHOLOGIC
FEATURES
 All 3 patterns demonstrate similar
histopath features.
 Consists of fragments of cellular
mesenchymal tissue
composed of spindle
-shaped fibroblasts &
collagen fibers with
numerous small
blood vessels.

134.  Free haemorrhage noted interspersed
throughout lesion.
 Within this fibrous CT background is a
mixture of woven
bone, lamellar
bone, &
cementum-like
particles.

135.  Proportion of each mineralised material
varies from lesion to lesion & from area
to area in individual sites of involvement.
 As the lesions mature & become more
sclerotic, the ratio of fibrous CT to
mineralised material decreases.
 With maturation, the bone trabeculae
become thick curvilinear structures that
– resemble the shape of ginger roots.

136.  With progression to the final radiopaque
stage, individual trabeculae fuse &
form lobular masses composed of
sheets or fused globules of relatively
acellular & disorganised cemento-
osseous material.

137. DIAGNOSIS
 Periapical dysplasia & florid cemento-
osseous dysplasiadistinct clinical &
radiographic patterns – strong
presumptive diagnosis without the
necessity of biopsy.
 Features of focal cemento-osseous
dysplasia are less specific – mandate
surgical investigation.

138.  Histopathology – also difficult to
distinguish focal cemento-osseous
dysplasia from ossifying fibroma.
 Findings at surgery – very helpful in
discriminating between these two
lesions.

139.  Before final sclerotic stage – COD
consists of easily fragmented & gritty
tissue that can be curetted easily from
the defect but does not separate cleanly
from the adjacent normal bone.
 In contrast , ossifying fibromas tend to
separate cleanly from the bone & are
removed in one or several large
masses.

140.  Several histopath features – help to
confirm impression obtained from
surgical & gross specimens.
 COD & ossifying fibroma demonstrate a
mixture of bone & cementum like
particles,
 the trabeculae in OF – more delicate &
often demonstrate osteoblastic rimming

141.  Cementum like particles
 In COD irregularly shaped & exhibit
retraction from the adjacent stroma
 In OF –more ovoid & demonstrate
brush borders in intimate association
with adjacent stroma.

142.  OF – exhibit haemorrhage along
margins of specimen
 COD –reveals free haemorrhage
throughout the lesion & a sinusoidal
vascularity in close association with
bony trabeculae.

143. TREATMENT &
PROGNOSIS
 Do not appear neoplastic.
 Do not require removal.
 During predominantly radiolucent phase,
the lesions cause few problems.
 Sclerosis present – COD tend to be
hypovascular & prone to necrosis with
minimal provacation.
 Asymptomatic pts – regular recall
examination with prophylaxis

144.  Onset of symptoms usually associated
with exposure of sclerotic masses 
biopsy or elective extraction of teeth
should be avoided.
 Other instances, symptoms begin after
exposure of the sclerotic masses – as a
result of progressive alveolar atrophy
under a denture.

145.  Affected pts should be encouraged to
retain their teeth to prevent development
of symptoms later.
 Management of symptomatic pt – more
difficult.
 At this stage – there is an inflammatory
component to the disease & process is
basically a chronic osteomyelitis
involving dysplastic bone &cementum.

146.  Antibiotics – indicated –but often not
effective.
 Sequestration of sclerotic cementum-
like masses occurs slowly & is followed
by healing.
 Saucerisation of dead bone  speed
healing.

147.  Single case of malignant fibrous
histiocytoma arising within a focus of
florid COD reported, such neoplastic
transformation appears unique.
 Prognosis for pts with COD – good.

148.  When simple bone cysts arise within foci
of COD, surgical exploration  to
establish diagnosis.
 These simple bone cysts often do not
heal as rapidly as those noted in
younger pt who does not have COD.

149.  In some cases cysts persist or enlarge
after surgical intervention; when they fill
in, the bone retains an abnormal
radiographic appearance.
 To assist healing, the cyst & surrounding
fibro-osseous proliferation are usually
curreted throughly.

150. OSSIYING FIBROMA
 Cementifying fibroma
 Cemento-ossifying fibroma
 Central ossifying fibroma of bone
 Central fibro-osteoma
 True neoplasm with significant growth
potential.
 Resemble focal COD radiographically &
to a lesser extent , histopathologically.

151.  Ossifying fibroma & cementifying
fibroma –thought to be two distinct
lesions
 Now widely accepted that they are
benign fibro-osseous lesions of probable
periodontal ligament origin, both lesions
representing histological variations of
the same neoplastic process(Hamner et
al.1968; Waldron & Giansanti 1973b).

152.  Eversole et al.(1985)  no specific
clinical, radiographic, or microscopic
predictor variables to separate these
lesions.
 Eversole & colleagues suggested that all
lesions in this group (viz. ossifying
fibroma, cementifying fibroma, &
cemento - ossifying fibroma)  to be
referred to as ossifying fibromas.
 These are same lesion & are classified
best as osteogenic neoplasms.

153.  Ossifying fibromas can be difficult to
differentiate from the non-odontogenic
lesions of fibrous dysplasia, thus
prompting pathologists to use the term
fibro-osseous lesions(Waldron 1970) as
a general designation for a group of
histologically similar jaw lesions which
can be either reactive or neoplastic in
nature.

154.  Eversole et al. (1985) observed that
‘these lesions share common
microscopic features whereby a
hypercellular fibroblastic vascular
stroma prevails, with elaboration of a
variety of calcifiable matrices
represented by woven bone, lamellar
bone, curvilinear trabeculae, & spheroid
“psammoma-like” calcifications.’

155.  The neoplasm is composed of fibrous
tissue that contains a variable mixture of
bony trabeculae, cementum-like
spherules or both.
 Same progenitor cell produces the
different materials.
 Suggested - Origin of these tumors is
odontogenic or from periodontal
ligament

156.  But microscopically identical neoplasms
with cementum like differentiation also
been reported in – orbital, frontal,
ethmoid, sphenoid, & temporal
bonestheories of origin -?
 Many authorities designate cementum-
like material present in ossifying
fibromas as a variation of bone.

157.  Recently mutation in tumor suppressor
gene HRPT2 – identified in ptswith rare
condition known as hyperparathyroidism
jaw-tumor syndrome, characterised by
 Parathyroid adenoma or carcinoma,
 Ossifying fibromas of the jaws,
 Renal cysts, &
 Wilm’s tumors.

158.  Subsequent finding of HRPT2 gene
mutations in two sporadic casses of
ossifying fibroma of the jaws.
 Function of HRPT2 protein product 
parafibromin & mechanism by which
mutations in this gene lead to tumor
formation- not well understood.

159. CLINICAL & RADIOGRAPHIC
FEATURES
 Occurs at any age.
 Greatest no. of cases diagnosed in third
& fourth decades of life.
 Female predilection.
 Mandible involved more often than
maxilla.
 Mandibular premolar & molar area -
most common site.

160.  In both jaws - lesion is always
associated with the tooth-bearing areas.
 Small lesion – seldom cause symptoms
– detected only on radiographic
examination.
 Larger tumors – painless swelling of
involved bone may cause facial
asymmetry or mild deformity.

161.  Pain & parasthesia – rarely associated
with OF.
 Displacement of teeth – may be an early
clinical feature.
 Relatively slow growing tumor.

162.  Present for some years before
discovery.
 Slow growth cortical plates of bone &
overlying mucosa or skin are almost
invariably intact.

163.  Radiograph – well defined & unilocular.
 Some show - sclerotic border.
 Depending on amount of calcified
material produced in the tumor
 Completely radiolucent
 Varying degrees of radiopacity – noted.
 True ossifying fibromas – largely
radiopaque with only a thin radiolucent
periphery. ( DD:- end stage focal COD)

164.  Root divergence or
 Resorption of roots of teeth associated
with tumor - seen.
 Large ossiying fibromas of mandible
often demonstrate a characteristic
downward bowing of the inferior cortex
of mandible.

165. SURGICAL FINDINGS
 At surgical exploration – lesion is well
demarcated from the surrounding bone.
 Permitting relatively easy separation of
tumor from its bony bed.
 Few ossifying fibromas – show, grossly
& microscopically, a fibrous capsule
surrounding tumor.
 Most – not encapsulated but well
demarcated grossly & microscopically
from the surrounding bone.

166.  On gross examination, tumor is usually
submitted in one mass or as few large
pieces.

167. HISTOPATHOLOGIC
FEATURES
 Exhibit variable microscopic features
depending on the ‘maturity’ of the lesion,
the quantity of calcified tissue present, &
the area of the lesion being examined.
 Predominant features of fibrous CT
component are
 Hypercellularity,
 Moderate vascularity, &
 Haphazard collagen orientation.

168.  Several types of calcified material may
be seen in ossifying fibromas.
 Eversole & colleagues(1985) have
described these as follows:
 Osseous products – consisting of
woven & lamellar trabeculae, often in
dense deposits;
 Spheroid-curvoid products- either
non-polarizable or exhibiting a
sharpey’s fibre-like fringe

169.  Dystrophic- appearing calcifications-
with a spheroidal configuration within a
fasciculated or storiform stroma;
 Anastomosing curvilinear trabeculae-
exhibiting micro-lamellar or quilted
patterns when viewed with crossed
polars, a feature observed in normal
root cementum.

170.  Ossifying fibromas consist of fibrous
tissue that exhibits varying degrees of
cellularity
& contains
mineralized
material.

171.  The hard tissue portion may be in the
form of trabeculae of osteoid & bone or
basophilic & poorly cellular spherules
that resemble cementum.
 Admixtures of the two types are typical.
 The bony trabeculae vary in size &
frequently demonstrate a mixture of
woven & lamellar patterns.
 Peripheral osteoid & osteoblastic
rimming are usually present.

172.  The spherules of cementum-like
material often demonstrate peripheral
brush borders that blend into the
adjacent
connective
tissue.

173.  Significant intralesional haemorrhage is
unusual.
 Variation in types of mineralised material
produced – helpful in DD of fibrous
dysplasia, which has more uniform
pattern of osseous differentiation.

174. TREATMENT &
PROGNOSIS
 Circumscribed nature – permits
enucleation of tumor with relative ease.
 Some – grown large & destroyed
considerable bone – necessitate
surgical resection & bone grafting.
 Prognosis- very good.
 Rare – recurrence.
 No evidence of malignant change.

175. JUVENILE OSSIFYING
FIBROMA
 Juvenile active ossifying fibroma.
 Juvenile aggressive ossifying fibroma.
 Controversial lesion – distinguished from
larger group of ossifying fibroma on
basis of the
 Age of pts,
 Most common sites of involvement,&
 Clinical behaviour.

176.  Two different neoplasms reported under
the term
1. Trabecular &
2. Psammamatoid.
 Among lesions involving craniofacial
skeleton , no. of psammamatoid
exceeds no. of trabecular – by ratio of
appx. 4:1.

177.  Recent study of 3 cases of
psammamatoid variant arising in orbit of
adolescent boys demonstrated the
 presence of nonrandom chromosomal
breakpoints at Xq26 & 2q33 resulting in
(X;2) translocation.
 No similar studies in trabecular variant
 Future insights into cytogenetic
abnormalities of these 2 variants may
aid in defining them in distinct entities.

178. CLINICAL & RADIOGRAPHIC
FEATURES
 Grow rapidly
 Well circumscribed, &
 Lack continuity with adjacent normal
bone.
 Age at diagnosis variesfrom younger
than 6 months to older than 70 years of
age.
 Although both patterns reveal similar
radiographic features & growth patterns,
trabecular form diagnosed initially in

179.  Mean age of
 trabecular JOF – appx. 11 years.
 psammamatoid JOF – 22 years.
 Both forms exhibit
 Slight male predilection.
 Occur in either jaw but reveal a maxillary
predominance.

180.  Although many tumors initially detected
on routine radiograph, cortical
expansion result in clinically detectable
facial enlargement
 Psammamatoid variant frequently
appears outside jaws , with more than
70% arising in orbital & frontal bones &
paranasal sinuses.

181.  Lesions are circumscribed
radiolucencies that in
some cases contain
central radiopacities.
 In some cases “ground
glass” radiopacification
observed.
 Within a sinus – appear
radiodense & often create
clouding that may be confused with
sinusitis

182.  Complications secondary to neoplasm -
as result of impingement on
neighbouring structures.
 With persistent growth, lesions arising in
paranasal sinuses penetrate the orbital,
nasal, & cranial cavities.
 Nasal obstruction,
 Exophthalmos, or
 Proptosis may be seen.
 Rarely temporary or permanent

183.  Intracranial extension – discovered in
cases arising adjacent to cribriform
plates.
 Because of circumscribed growth
pattern frontal lobe – elevated without
any associated neurologic signs.
 Rarely intracranial extension  resulted
in meningitis.( one report of maxillary
tumor leading to convulsions & death
from pneumococcal meningitis)

184.  Some cases of psammamatoid variant -
development of aneurysmal bone cyst
reported.
 Such cystic changes tend to occur in
younger pts in 1st & 2nd decades of life –
associated with large maxillary lesions
exhibiting aggressive behaviour.

185. HISTOPATHOLOGIC
FEATURES
 Both patterns - typically
nonencapsulated but well demarcated
from the surrounding bone.
 Tumor consists of cellular fibrous
connective tissue that exhibits areas that
are so cellular that the cytoplasm of
individual cells is hard to discern
because of nuclear crowding.
 Myxomatous foci – not rare – often
associated with pseudocystic
degeneration.

186.  Areas of haemorrhage & small clusters
of multinucleated giant cells – usually
seen.
 Mineralised component in two patterns
is very different.
 Trabecular variant – irregular strands of
highly cellular osteoid encasing plump &
irregular osteocytes.

187.  Strands often lined by plump osteoblasts
& in other areas by multinucleated
osteoclasts.

188.  Psammamatoid pattern forms
 concentric lamellated and spherical
ossicles that vary in shape &
 typically have basophilic centers with
peripheral eosinophilic osteoid rims.
 A peripheral brush border blending into
surrounding stroma – noted in many
ossicles.

189.  Occasionally, individual ossicles
undergo remodeling & form crescentic
shapes.

190. TREATMENT & PROGNOSIS
 Clinical management & prognosis –
uncertain.
 Many tumors slow, but progressive
growth.
 Some demonstrate rapid enlargement.
 More aggressive neoplasms tend to
arise in infants & young children.

191.  Smaller lesions – complete local
excision or thorough curettage-
adequate.
 Rapidly growing lesions- wider
resection.
 30% - 58% recurrence rate.
 Malignant transformation – not
documented.

192. BIBILIOGRAPHY
 SHAFER’S Textbook Of Oral Pathology
– 6th edition – R RAJENDRAN;B
SIVAPATHASUNDARAM
 Oral & Maxillofacial Pathology – 3rd
edition – NEVILLE : DAMM
 Oral Diseases In The Tropics –
S.R.PRABHU
 Lucas’s Pathology Of Tumors Of The
Oral Tissues – 5th edition – RODERICK
A. CAWSON

194. CENTRAL OSSIFYING FIBROMA OF
BONE
 CENTRAL FIBRO-OSTEOMA
 It now appears that this represents a
definite entity which should be
separated from fibrous dysplasia of
bone & other fibro-osseous lesions
which do not represent true neoplasms.
 This concept has been discussed by
Pindborg, by Waldron & by many others.

195.  There is remarkable similarity in clinical
features between this lesion & the
central cementifying fibroma, a tumor
accepted by most investigators as being
odontogenic in origin.
 Considerable similarity & even overlap
in histologic features of these 2 lesions.

196.  For these reasons it has been
suggested that:
 These are two separate benign tumors,
identical in nature except for the cell
undergoing proliferation,
Osteoblast with bone formation in one case
Cementoblast with cementum formation in
other case.
 These represent simply two facet of the
same basic tumor.

197.  Further investigation necessary to clarify
the relationship, or lack of it, between
the central ossifying fibroma & the
central cementifying fibroma.