Bone disorders- Dr PC Anila Namboodiripad, Professor and PG guide-Royal Dental College, Chalissery, Palghat District, Kerala

1. Cleidocranial dysplasia

2. Etiology
 a rare congenital disorder of bone with
 an autosomal dominant hereditary
mode of inheritance with complete
penetrance, but variable expressivity

3.  caused by mutation in the CBFA1gene
mapped on chromosome 6p21
 encoding transcription factor RUNX2
 responsible for osteoblast
differentiation

4. Clinical features
 Moderately short stature, and
 They tend to have a short head from
front to back (brachycephaly) and
 a prominent forehead (frontal bossing).
 delayed closure of fontanels, and some
adults with CCD have open fontanels.
 The eyes are widely spaced, and
 the nasal bridge is often flat.

5.  one or both clavicles are frequently
partially or in 10% cases completely
absent.
 The neck appears long, and the
shoulders are narrow and down-
sloping
 hypermobility of shoulders with
tendency to approximate shoulders
anteriorly

8. Oral manifestations
 prolonged retention of deciduous
dentition and delayed eruption of
permanent teeth.
 Adults have mixed dentition in their
oral cavities.
 show a large number of unerupted
supernumerary teeth, often mimicking
a premolar.

9.  Delayed and imperfect ossification of
the cranium,
 Maxilla is also underdeveloped along
with ill-formed paranasal sinuses.
 Skeletal Class III tendency /
mandibular prognathism in CCD->
uninterfered growth due to hypoplastic
maxilla and upward and forward
mandibular rotation.

10. Treatment
 No specific treatment suggested

12. Cherubism

13. Etiology
 SH3-binding protein SH3BP2 mapped
to 4p16.3, an important molecule in
cell signaling
 There is bone loss followed by the
accumulation of fibrous tissue that
causes facial swelling especially
around the cheeks, hence the
disease's name.

14. Clinical features
 Age: in children
 Sex: M=F
 Site: Mand>max

15.  severe bone degradation of both the
upper and lower jaws beginning at
about age three.
 In adult life, complete involution of the
lesions

16.  In some cases, the enlargement of the
floor of the orbit (the bones
surrounding the eye socket) causes
the eyeball to tip upward.
 The name derived from cherub
(angelic looking, as depicted in
Renaissance paintings)

17. Oral manifestations
 Abnormal patterns of teeth eruption
 teeth agenesis and the presence of
ectopic or retained teeth.

18. X-ray
 multilocular radiolucencies->near the
angle of the mandible and spreading
to the mandibular ramus and body.

20. HP
 The histology is limited for diagnosis,
showing fibrous hyperplasia and
multinucleated giant cells.
 similar to those other bone diseases
such as
 brown tumor of
hyperparathyroidism,
 giant cell tumor, and
 central and peripheral giant cell
granuloma

21. Lab diagnosis
 the bone markers
 phosphorous,
 serum calcium, and
 alkaline phosphatase are usually
at normal levels with respect to age.

22.  cherubism may be associated with
other genetic diseases, such as
Noonan’s syndrome and Ramon
syndrome.

23. Treatment
 multinucleated cells in cherubic
lesions ->osteoclasts from a structural
and biochemical standpoint so
calcitonin is the treatment of choice.

24. Pagets disease of bone

25. Pathogenesis
 Paget disease occurs when there is a
disturbance in the bone remodeling
 that characteristically begins with
unwarranted bone resorption followed by an
increase in bone formation.
 This osteoclastic hyper activity followed by
substituted osteoblastic activity leads to the
formation of a structurally disordered mosaic
of bone which is still a woven bone,
 and which is mechanically larger, weaker,
more vascular, less compact, and more prone
to fracture than normal adult lamellar bone

26.  Slow virus:
 paramyxovirus
 respiratory synctial virus
 Sequestrome 1 gene on chromosome
5.

27. Clinical features
 Age: occurs in the aging skeleton
 Sex:M=F
 Site skull, spine, pelvis, and long
bones of the lower extremity.

28. Presentation
 The bone pain is dull, constant,
boring, and deep below the soft
tissues.
 It may persist or exacerbate during the
night.
 Pathologic fractures commonly result
from weakened pagetic bone.

29.  Nonspecific headaches,
 impaired hearing, and tinnitus commonly
result from skull involvement and
compression of the 8th cranial nerve
 The patient's hat size may increase (or,
less commonly, decrease) as a result of
skull enlargement or deformity.
 These may manifest as nausea,
dizziness, syncope, ataxia, incontinence,
gait disturbances, or dementia.

30.  3 phases:
 Lytic
 Mixed
 Sclerotic

31. Oral manifestations
 Facial disfigurement and
malocclusion may be observed
following enlargement of the maxilla or
mandible.
 Tooth loss may occur with progressive
root resorption.

32. X-Ray
 Absent periodontal membranes and
lamina dura are associated with
hypercementosis.

33.  Both osteolysis (seen as radiolucency)
and excessive bone
formation(radiopacity) and a mixed state
occurs.
 There are specific X-ray features of
Paget's disease that include:
◦ A classical V-shaped pattern between healthy
and diseased long bones known as 'the
blade of grass' lesion.
◦ The 'cotton wool' pattern in the skull that is
also characteristic (multifocal sclerotic
patches).-osteitis circumscripta

34. HP
 woven bone and irregular broad
trabeculae with disorganized cement lines in
a mosaic pattern. Woven bone seperated by
reversal lines
 fibrous vascular tissue interspersed between
trabeculae
 profound bone resorption - numerous
large osteoclasts with multiple nuclei per cell
◦ virus-like inclusion bodies in osteoclasts
◦ Paget's osteoclasts larger, more nuclei than
typical osteoclasts
 Multinucleated giant cells-3-30 as opposed to
1-3 in normal osteoclasts

35. Treatment
 NSAIDs
 Bisphophonates
 Calcitonin
 Surgery

36. Lab investigations
 Bone-specific alkaline phosphatase
(BSAP) levels are raised.
 Urine hydroxyproline ↑.
 Serum calcium, phosphorus, and
parathyroid hormone levels are
usually normal but immobilization may
lead to hypercalcaemia.