Third year bds

1. Fibro-osseous lesions
I. Bone dysplasias
a. Fibrous dysplasia
i. Monostotic
ii. Polyostotic
iii. Polyostotic with endocrinopathy
(McCune-Albright)
iv. Osteofibrous dysplasia
b. Osteitis deformans
c. Pagetoid heritable bone
dysplasias of childhood
d. Segmental odontomaxillary
dysplasia
II. Cemento-osseous dysplasias
a. Focal cemento-osseous dysplasia
b. Florid cemento-osseous dysplasia
III. Inflammatory/reactive processes
a. Focal sclerosing osteomyelitis
b. Diffuse sclerosing osteomyelitis
c. Proliferative periostitis
IV. Metabolic Disease:
Hyperparathyroidism
V. Neoplastic lesions (Ossifying
fibromas)
a. Ossifying fibroma NOS
b. Hyperparathyroidism jaw lesion
syndrome
c. Juvenile ossifying fibroma
i. Trabecular type
ii. Psammomatoid type
d. Gigantiform cementomas

2. FIBROUS DYSPLASIA
 Condition in which normal medullary bone is gradually
replaced by an abnormal fibrous connective tissue
proliferation
 This mesenchymal tissue contains varying amounts of
osteoid that presumably arises through metaplasia.
 Due to a defect in osteoblast differentiation and
maturation

3. ETIOLOGY: -
1. Hamartomatous
2. Abnormal reaction of bone to a localized traumatic
episode
3. Mutation of GNAS1 gene – which codes for a G protein
which stimulates cAMP production. This leads to :-
- effect on differentiation of osteoblasts
- hyperfunction of affected endocrine glands
- increased prolifearation of melanocytes

4. TYPES OF FIBROUS DYSPLASIA: -
1. Monostotic: Fibrous dysplasia (FD) limited to one
single bone. Accounts for 70% – 80% of all cases
2. Polyostotic: FD affects several bones. 20-30% cases
(a) Jaffe type – severe FD with almost entire
skeleton involved.
(b) McCune-Albright syndrome – along with
polyostotic FD, multiple cutaneous pigmentations
and hyperfunction of one or more endocrine glands.

5. 3. Craniofacial form
4. Cherubism

6. MONOSTOTIC FIBROUS DYSPLASIA
Clinical Features : -
Age incidence: 1st or 2nd decade of life.
Sex incidence: equal
Site predilection:
 Ribs, tibia, femur, craniofacial bones
 Maxilla involved more than mandible.
 Maxillary lesions often involve adjacent bones like
zygoma, sphenoid etc

7. Signs & symptoms:
 First clinical sign is a painless,
gradually enlarging swelling
 Usually involves buccal cortical plate
 Causes protuberance of inferior border
of mandible
 Teeth may be displaced by the mass
 Maxillary lesions – more complications

8. POLYOSTOTIC FIBROUS DYSPLASIA
Clinical Features : -
Age incidence: 1st decade of life, earlier
Sex incidence: Equal
Site predilection: Skull and facial bones, pelvis, spine
and shoulder girdle

10. Signs & symptoms: -
 Pathological fractures, other bone
symptoms
 Patients with McCune-Albright
syndrome have café-au-lait (coffee
with milk) pigmentation.
 Typically, margins of the spots are
irregular, unlike those of
neurofibromatosis, where the spots
have smooth borders
( Also occurs ipsilateral to the side of
bone involvement )

11. Coast of Maine –
Irregular borders –
McCune Albright
syndrome
Coast of California –
Smooth borders –
Neurofibramatosis

12.  Hyperthyroidism
 Acromegaly
 Precocious puberty
 Hyperparathyroidism
 Hypophosphatemic rickets
 Severe cases – hepatic (increased hepatic transaminases)
- cardiac (cardiomyopathy)
- GI polyposis
 Mazabraud’s syndrome – association b/w FD and
intramuscular myxoma

13. RADIOGRAPHIC FEATURES: -
 Early stages – mixed radiopaque-
radiolucent appearance.
(well-defined radiolucency containing
network of fine bony trabaculae)
 Later stages show a characteristic
“ground glass / orange peel (peau d’
orange)” appearance of affected bones.
- opaque with many delicate trabaculae

14.  Lesions not well defined and blend into adjacent bone –
limits of lesion cannot be defined.
 Lesions in jaws displace roots of teeth
 Distortion of nasal cavity and obliteration of paranasal
sinuses
 Rind sign – lucent lesions with sclerotic borders

15. HISTOLOGICAL FEATURES: -
 Lesion shows typical irregularly
shaped trabeculae of immature
woven bone in a cellular, loosely
arranged fibrous stroma
 Theses trabeculae are not
connected to each other
 They often assume curvilinear
shape, which have been linked to
Chinese script writing or
Cuneiform pattern

16.  These trabeculae are believed to arise due to
metaplasia and are not bordered by plump,
functional osteoblasts
 The surrounding stroma is highly cellular and
vascular
 Tiny calcified spherules maybe seen in some areas
 Lesional bone fuses directly with normal bone at the
periphery, no demarcation

17. Irregular trabaculae of woven bone in a fibrous matrix

18.  Long standing lesions of jaws and skull, esp in old
patients, tend to be more ossified
 May show lamellar deposition of trabculae
 Not seen in long bones

19. Lamellar maturation of bone

20. DIFFERENTIAL DIAGNOSIS: -
 Clinically, FD must be differentiated from
1. Ossifying fibroma
2. Paget’s disease.
 Though, its radiographic appearance is typical, it must
be distinguished from
1. Hyperparathyroidism.
2. Paget’s disease (early stage).

21. CHERUBISM
Rare developmental jaw condition, first
described by Jones in 1933.
- called it familial multilocular disease
of the jaw.
Transmitted as an autosomal dominant
trait.

22.  Causes characteristic bilateral posterior
mandibular swelling
- the child appears as a plump cheeked angels
called “Cherub” in Renaissance paintings.

23. Pathogenesis
 The gene for cherubism was mapped to chromosome
4p16 ( SH3BP2 gene )
 The protein encoded by this gene is believed to function in
signal transduction pathway and to increase the activity of
osteoclasts and osteoblasts during growth phase
 It has been suggested that mutation in SH3BP2 gene may
lead to pathologic activation of osteoclasts and disruption
of jaw morphogenesis

24.  The appearance of people with the disorder is
caused by a loss of bone, which the body replaces
with excessive amounts of fibrous tissue.

25. CLINICAL FEATURES: -
Age incidence: Affected children, are normal at the birth and
are without any clinically or radiographically evident disease
until 14 months to 3 yrs of age
The jaw lesion remit spontaneously when the child reaches
puberty, but reason for this remission is still unknown.
Sex incidence: males = females

26. Site predilection:
 Mostly bilateral involvement
 Painless and symmetrical expansion
 Mandible affected more commonly than maxilla
 In maxilla, tuberosity region is affected frequently
- resulting in respiratory obstruction and
impairment of vision & hearing
 Cervical lymphadenopathy contributes to the
patients full faced appearance

27.  Skin of upper face is stretched
 A rim of sclera may be seen beneath the
iris, giving a classical “eyes upturned
to heaven” appearance
- due to involvement of the
infraorbital rim and orbital floor that
tilts the eyeball upwards, as well as to
stretching of the facial skin that pulls
the lower lid downwards.

28.  Developing teeth displaced, fail to
erupt.
 Numerous dental abnormalities have been
reported, such as agenesis of the 2nd & 3rd
mandibular molars, premature exfoliation of
the primary teeth, delayed eruption of the
permanent teeth, displacement of the teeth
and transposition and rotation of the teeth.
 The permanent dentition is often defective.
 In severe cases root resorption occurs.

29.  It is been connected to NOONAN’S SYNDROME
- short stature, cherubic facies, congenital heart defect,
chest deformity, low I.Q.
 Grading system, Arnott (1978)
Grade I: involvement both ascending rami of mandible
Grade II: involvement both maxillary tuberosities as well as
both ascending rami of mandible
Grade III: involvement of the whole maxilla and mandible
except the coronoid process and condyles

30. RADIOGRAPHIC FEATURES
 Appear as expansile, multilocular
radiolucency.
 The presence of numerous unerupted
teeth and the destruction of the
alveolar bone may displace the teeth,
producing a radiographic appearance
referred as floating tooth syndrome.
 With adulthood, the cystic areas in the
jaws become re-ossified, which results
in irregular patchy sclerosis.
 There is classic but non specific
ground glass appearance because of
the small, tightly compressed
trabecular pattern.

31. HISTOLOGICAL FEATURES
 Normal bone is partly replaced by
pathologic tissue
 Numerous randomly distributed
multinucleated giant cells and
vascular spaces within a fibrous
connective tissue stroma
 An increase in osteoid and newly
formed bone matrix is found in the
peripheral region
 An eosinophilic perivascular cuffing
is seen

32. Multinucleated giant cells are scattered
in vascular fibrous stroma. Osteoid and
newly formed bone matrix are visible
Multinucleated giant cells are
scattered around blood vessels

33. Multinucleated giant cells in cherubism are
positive for tartrate resistant acid
phosphatase (TRAP)

34. DIFFERENTIAL DIAGNOSIS
 Giant cell granulomas of the jaw
 Osteoclastomas
 Aneurysmal bone cyst
 Fibrous dysplasia
 Hyperparathyroidism

35. TREATMENT
 It is based on the known natural course of the disease
and the clinical behaviour of the individual case.
 If necessary surgery is undertaken only after puberty.

36. PAGET’S DISEASE OF BONE
(Osteitis deformans)
 Characterized by excessive and abnormal remodelling of
bone, resulting in distortion and weakening of bone.
 Sir James Paget
 Pagetic bone - extensively vascularized, weak, enlarged
and deformed with subsequent complications.

37. ETIOLOGY: -
 Unknown, but predisposing factors could be –
Genetic – 7 to 10 fold increase in relatives
Slow virus infection – inclusion bodies in Pagetic osteoclasts
Inflammatory - response to NSAIDs
Endocrine factors – PTH levels

38. CLINICAL FEATURES
Age incidence: Middle aged individuals
Sex incidence: Male to female ratio is 2:1
Site predilection: Bones of skull, lumbar vertebrae,
pelvis, femur and tibia
Common in England, France and Germany.
Rare in Middle and Far East Asia and Africa.

39.  Severe bone pain and limitation of
joint movements
- dull, constant aching pain ,may exacerbate
at night
 Pathologic fractures
 Affected bones – thickened, enlarged and
weak
 Weight bearing joints/bones become
bowed – Simian stance
 Rise in temperature on the skin overlying
involved bone

40.  Skull involvement – increase in head circumference
 Platybasia – softened bone at base of skull
– descend of cranium into cervical spine
 Non-specific head aches, dizziness, dementia, tinnitus,
impaired hearing, changes in vision, cranial nerve
palsies
 Back and neck pain – affects spine

41.  Maxilla affected more than mandible
 Maxilla – enlargement of middle third
of face (leontiasis ossea)
 Nasal obstruction, obliterated sinuses
and deviated septum also occur
 Mandible involved rarely – may cause
prognathism
 In dentulous patients spacing of teeth
is seen, while edentulous patients
complains of tightness of the dentures

42. RADIOGRAPHIC FEATURES
 Early stage (osteolytic) -
radiolucency and alteration of
trabecular pattern
Isolated areas (osteoporosis
circumscripta)-diffuse areas
 Late stage (osteoblastic) – patchy
areas of sclerotic bone is formed,
called “cotton wool” appearance

43.  Dental radiographs also
show the classical cotton
wool appearance
 Extensive hypercementosis
can be noted

44. DIFFERENTIAL DIAGNOSIS: -
 Acromegaly.
 Florid cemento- osseous dysplasia.
 Sclerosing osteomyelitis (diffuse type).
 Osteosarcoma.
 Adult osteopetrosis

45. LABORATORYFINDINGS: -
 Abnormally elevated serum alkaline
phosphatase level upto 250 Bodansky units
(normal – 30 to 40);
but normal calcium and phosphorous levels.
 Increased urinary calcium and hydroxyproline
levels.

46. HISTOLOGICAL FEATURES
 Alternating bone resorption and
deposition seen
 Depends on stage of the disease
1) Osteolytic phase
 Disordered areas of resorption
 Increased number of abnormally
large osteoclasts
(upto 100 nuclei)

47. 2) Osteoblastic phase
 Haphazard laying of new
bone matrix (woven bone)
 Repeated bone removal &
deposition – formation of
many small irregularly shaped
bone fragments – joined
together in jigsaw or mosaic
pattern (hallmark H/P
feature)
 Basophilic reversal lines
 High vascularity, increased
number of capillaries, dilated
arterioles and venous sinuses

48.  Pagetic bone is coarse and fibrous with distortion of
normal trabecular arrangement
 Shows no tendancy to form Haversian systems or to
center on blood vessels
3) Osteoporotic phase
 Burned-out phase
 New bone is disordered, poorly mineralized and lacks
structural integrity
 Proliferation of bone and concomitant
hypercementosis may result in obliteration of PDL

49. Treatment
 It is a chronic and slow growing diease, it is seldom the
cause of death.
 Bone pain is mostly controlled by anti-inflammatory
drugs.

50. OSTEOGENESIS IMPERFECTA
 Most common type of developmental bone disorder,
showing both autosomal dominant and recessive pattern.
 Comprises heterogeneous group of heritable CT disorder in
which bone fragility is the primary feature.
 Synonyms- Brittle bone disease
- Fragilitas ossium
- Osteopsathyrosis
- Lobstein’s disease