Bone /cosmetic dentistry courses

Bone , itsBone , its
disorders anddisorders and
treatmenttreatment
INDIAN DENTAL ACADEMYINDIAN DENTAL ACADEMY
Leader in Continuing Dental EducationLeader in Continuing Dental Education
www.indiandentalacademy.com

AGENDAAGENDA
 IntroductionIntroduction
 EmbryologyEmbryology
 Development of boneDevelopment of bone
 Classification of boneClassification of bone
 CompositionComposition
 Gross histologyGross histology
 Ultrastructure of boneUltrastructure of bone
 Bone cellsBone cells
 Bone remodellingBone remodelling
 Bone disorders and treatmentBone disorders and treatment

INTRODUCTIONINTRODUCTION
 Bone is a hard, specialized connective tissue with aBone is a hard, specialized connective tissue with a
calcified collagenous intercellular substancecalcified collagenous intercellular substance
 Functions of bone includeFunctions of bone include
- skeletal support of the body- skeletal support of the body
- protection to internal organs- protection to internal organs
- increases efficiency of muscle action- increases efficiency of muscle action
- reservoir of minerals- reservoir of minerals
- hosts hematopoietic cells- hosts hematopoietic cells

EMBRYOLOGYEMBRYOLOGY
 Skeletal systemSkeletal system
develops fromdevelops from
1.1. paraxial & lateralparaxial & lateral
plate mesoderm -plate mesoderm - axialaxial
& appendicular bones& appendicular bones
2. Neural crest -2. Neural crest -
cranial bonescranial bones

EMBRYOLOGYEMBRYOLOGY (cont..)(cont..)
 Somites differentiate intoSomites differentiate into
1. Dorsolateral part – dermomyotome1. Dorsolateral part – dermomyotome
2. Ventromedial part – sclerotome2. Ventromedial part – sclerotome
 End of 4End of 4thth
week – sclerotome cells –week – sclerotome cells –
condensation – mesenchymecondensation – mesenchyme

DEVELOPMENT OF BONEDEVELOPMENT OF BONE
 Bone development is calledBone development is called osteogenesis orosteogenesis or
ossificationossification
 Two mechanisms -Two mechanisms - intramembranous
- endochondral

Intramembranous ossification:Intramembranous ossification:
Mesenchymal condensationMesenchymal condensation
Increased vascularityIncreased vascularity
A membrane is formed ( collageA membrane is formed ( collage
fibres)fibres)

Mesenchymal cells enlargeMesenchymal cells enlarge
to become osteoblastto become osteoblast
Secretion ofSecretion of
gelatinous matrixgelatinous matrix
Fibres swellFibres swell
up(osteoid)up(osteoid)

INTRAMEMBRANOUS OSSIFICATIONINTRAMEMBRANOUS OSSIFICATION

Intramembranous ossification(cont..)Intramembranous ossification(cont..)

Intramembranous ossification(cont..)Intramembranous ossification(cont..)
Deposition of calcium saltsDeposition of calcium salts
Layer of osteoid becomes lamellasLayer of osteoid becomes lamellas
of bone (trabeculae)of bone (trabeculae)
Anastomosing network of trabeculaeAnastomosing network of trabeculae
form spongy or cancellous boneform spongy or cancellous bone
Continuing appositional growth &Continuing appositional growth &
remodelling of bony trabeculae -remodelling of bony trabeculae -
convert cancellous bone intoconvert cancellous bone into
compact bonecompact bone

Endochondral ossificationEndochondral ossification
Mesenchymal condensation –Mesenchymal condensation –
differentiation intodifferentiation into
chondroblasts – cartilagechondroblasts – cartilage
model with perichondriummodel with perichondrium
Capillaries grow intoCapillaries grow into
perichondrium – inner layerperichondrium – inner layer
differentiates into osteoblastsdifferentiates into osteoblasts
– thin collar of bone matrix– thin collar of bone matrix
formsforms
Perichondrium is now calledPerichondrium is now called
periosteumperiosteum
Thin collar of bone –Thin collar of bone –
subperiosteal bonesubperiosteal bone

EndochondralEndochondral
ossification(cont..)ossification(cont..)
 osteogenic cells & periosteal capillariesosteogenic cells & periosteal capillaries
invade cartilage model - periosteal budinvade cartilage model - periosteal bud
forms – initiate primary centre offorms – initiate primary centre of
ossification ( primary areolae)ossification ( primary areolae)
 Osteogenic cells give rise toOsteogenic cells give rise to
osteoblasts- arranged along secondaryosteoblasts- arranged along secondary
areolaeareolae
 Layer of ossein fibrils embedded inLayer of ossein fibrils embedded in
gelatinous intercellular substancegelatinous intercellular substance
 Osteoid is calcified and a lamellae ofOsteoid is calcified and a lamellae of
bone is formedbone is formed

ENDOCHONDRAL OSSIFICATIONENDOCHONDRAL OSSIFICATION
(cont..)(cont..)
 At this stage, forming boneAt this stage, forming bone
consists ofconsists of
1. Elongating collar of bone1. Elongating collar of bone
along the midsectionalong the midsection
–– diaphysisdiaphysis
2. Cartilaginous ends –2. Cartilaginous ends –
epiphysesepiphyses
 Secondary centre ofSecondary centre of
ossification develops inossification develops in
epiphyses – ossificationepiphyses – ossification
spreads from this centre in allspreads from this centre in all
directionsdirections

ENDOCHONDRAL OSSIFICATIONENDOCHONDRAL OSSIFICATION
(cont..)(cont..)
 Cartilage remains asCartilage remains as
1. Articular cartilage – covers1. Articular cartilage – covers
articular surfacearticular surface
2. Epiphyseal plate – transverse disc2. Epiphyseal plate – transverse disc
of hyaline cartilageof hyaline cartilage
 Epihyseal plate enables bone toEpihyseal plate enables bone to
grow until full adult stature isgrow until full adult stature is
attainedattained
 The zones of epiphyseal plate areThe zones of epiphyseal plate are
- zone of resting cartilage- zone of resting cartilage
- zone of proliferating cartilage- zone of proliferating cartilage
- zone of maturing cartilage- zone of maturing cartilage
- zone of calcifying cartilage- zone of calcifying cartilage

MINERALIZATION OF BONEMINERALIZATION OF BONE
 Bone tissue that is uncalcified is called osteoidBone tissue that is uncalcified is called osteoid
 calcification front - interface between osteoid &calcification front - interface between osteoid &
surrounding calcified bone - calcification beginssurrounding calcified bone - calcification begins
 Critical factor determining mineralization is localCritical factor determining mineralization is local
[Ca[Ca2+2+
] x [P] x [Pii
] ion into crystalline hydroxapatite] ion into crystalline hydroxapatite
[Ca[Ca55(PO(PO44))33OH]OH]

(cont..)(cont..)
 Three theories of calcification are:Three theories of calcification are:
1. Phosphatase theory1. Phosphatase theory – by Robison– by Robison
- Alkaline phosphatase releases inorganic phosphate ionsAlkaline phosphatase releases inorganic phosphate ions
from organic phosphatesfrom organic phosphates
- Phosphate ions react with Ca ions in tissue fluids leadingPhosphate ions react with Ca ions in tissue fluids leading
to precipitation of insoluble calcium phosphateto precipitation of insoluble calcium phosphate

MINERALIZATION OF BONEMINERALIZATION OF BONE (cont..)(cont..)
2. Seeding theory2. Seeding theory - by Glimcher et al- by Glimcher et al
-- Certain substances like collagen & chondroitin sulfateCertain substances like collagen & chondroitin sulfate
acts as a seed which induce crystallization ofacts as a seed which induce crystallization of
hydroxyapatitehydroxyapatite
- Regions in these molecules might have distribution of- Regions in these molecules might have distribution of
electric charges or spatial configuration for attachment ofelectric charges or spatial configuration for attachment of
ionsions

(cont..)(cont..)
3. Matrix vesicle theory3. Matrix vesicle theory – by Anderson– by Anderson
-- Matrix vesicles are membrane bound structures, 25nm toMatrix vesicles are membrane bound structures, 25nm to
250nm in diameter250nm in diameter
- Rounded outgrowths of cell membrane that bud from- Rounded outgrowths of cell membrane that bud from
chondrocytes, osteoblasts & odontoblastschondrocytes, osteoblasts & odontoblasts
- Contain alkaline phosphatase & ATPase- Contain alkaline phosphatase & ATPase
- Act as calcification initiators- Act as calcification initiators

Decalcification:Decalcification:
 Nitric acid – 5 -10%, rapid but damage to tissueNitric acid – 5 -10%, rapid but damage to tissue
and inhibit nuclear staining.and inhibit nuclear staining.
 Formic acid – 10-30%, slow but less damage toFormic acid – 10-30%, slow but less damage to
tissue structures and staining.tissue structures and staining.
 EDTA – 20%, slow but superior to other agentsEDTA – 20%, slow but superior to other agents

CLASSIFICATION OF BONECLASSIFICATION OF BONE
 BasedBased on shapeon shape
FlatFlat - skull- skull
Tubular /longTubular /long - femur, humerus- femur, humerus
IrregularIrregular - facial bones- facial bones
 Based on locationBased on location
Axial skeleton - skull, vertebral columnAxial skeleton - skull, vertebral column
Appendicular skeleton - pectoral, pelvisAppendicular skeleton - pectoral, pelvis

CLASSIFICATION OF BONECLASSIFICATION OF BONE (cont..)(cont..)
 Based on MatrixBased on Matrix
arrangementarrangement
Lamellar boneLamellar bone
woven bonewoven bone

 Based on cross sectionBased on cross section
spongy bonespongy bone

 Based onBased on
developmental origindevelopmental origin
intramembraneousintramembraneous
intracartilagenousintracartilagenous

COMPOSITION OF BONECOMPOSITION OF BONE
 Bone : 67% inorganicBone : 67% inorganic
33% organic – 28% collagen33% organic – 28% collagen
- 5% noncollagen- 5% noncollagen
 Inorganic mineral:Inorganic mineral:
- consists of calcium phosphate salt in form ofconsists of calcium phosphate salt in form of
hydroxapatitehydroxapatite
--

COMPOSITION OF BONECOMPOSITION OF BONE (cont..)(cont..)
 Organic matrix:Organic matrix:
1. Collagen – primarily type I1. Collagen – primarily type I
trace amounts of type III,V,XI,XIIItrace amounts of type III,V,XI,XIII
2. Noncollagenous ground substance:2. Noncollagenous ground substance:
I.I. Structural components:Structural components:
a. proteoglycans – chondroitin sulfate, heparan sulfatea. proteoglycans – chondroitin sulfate, heparan sulfate
- incorporated as decorin & biglycan- incorporated as decorin & biglycan
- organizes collagen fibres- organizes collagen fibres
- seed for mineralization- seed for mineralization

COMPOSITION OF BONECOMPOSITION OF BONE (cont..)(cont..)
b. gylcoproteins – fibronectin, thrombospondin,b. gylcoproteins – fibronectin, thrombospondin,
osteonectin, osteopontin,osteonectin, osteopontin,
bone sialoproteinbone sialoprotein
c.c. γγ carboxy glutamic acid containing proteins – matrix glacarboxy glutamic acid containing proteins – matrix gla
proteins, osteocalcinproteins, osteocalcin
II.II. Non structural components:Non structural components:
a. enzymes – alkaline phosphatase, collagenasea. enzymes – alkaline phosphatase, collagenase
b. growth factors – FGF, GF, TGFb. growth factors – FGF, GF, TGFββ
c. bone morphogenetic proteins – BMP-2, BMP-7c. bone morphogenetic proteins – BMP-2, BMP-7

GROSS HISTOLOGY OF BONEGROSS HISTOLOGY OF BONE
 DenseDense outer sheet of compact bone & aouter sheet of compact bone & a
central medullary cavitycentral medullary cavity
 Medullary cavityMedullary cavity filled with yellow or redfilled with yellow or red
marrow – interrupted by network of bonymarrow – interrupted by network of bony
trabeculae (cancellous/spongy bone)trabeculae (cancellous/spongy bone)

COMPACT BONECOMPACT BONE

(cont..)(cont..)
 Mature bones consist of microscopic layers ofMature bones consist of microscopic layers of
calcified bone matrixcalcified bone matrix – lamellae– lamellae
 3 distinct types of lamellae are:3 distinct types of lamellae are:
 Circumferential lamellaeCircumferential lamellae ::
- circular lamallae lining external surface of- circular lamallae lining external surface of
cortex adjacent to periosteum & innercortex adjacent to periosteum & inner
surface of cortex next to endosteumsurface of cortex next to endosteum

COMPACTCOMPACT BONEBONE

GROSS HISTOLOGY OF BONEGROSS HISTOLOGY OF BONE (cont..)(cont..)
 Concentric lamellae :Concentric lamellae :
- make up bulk of compact bone- make up bulk of compact bone
- form basic unit of bone (osteon)- form basic unit of bone (osteon)
 Interstitial lamellaeInterstitial lamellae ::
- interspersed between adjacent concentric- interspersed between adjacent concentric
lamellae & fill spaces between themlamellae & fill spaces between them
- represent fragments of preexisting concentric- represent fragments of preexisting concentric
lamellaelamellae

 Outer aspect of compact bone is connective tissueOuter aspect of compact bone is connective tissue
membrane –membrane – periosteumperiosteum
 2 layers of periosteum are:2 layers of periosteum are:
a.a. Outer fibrous layer-Outer fibrous layer- dense irregulardense irregular
connective tissueconnective tissue
b.b. Inner osteogenic layerInner osteogenic layer – bone cells &– bone cells &
rich microvascular supplyrich microvascular supply

PERIOSTEUMPERIOSTEUM

 Functions of periosteumFunctions of periosteum are :are :
- provides a medium for attachment of- provides a medium for attachment of
muscles, tendons & ligamentsmuscles, tendons & ligaments
- nutritive function- nutritive function
- form bone when required- form bone when required
- fibrous layer is a limiting membrane- fibrous layer is a limiting membrane

(cont..)(cont..)
 Internal surfaces of compact & cancellous boneInternal surfaces of compact & cancellous bone
covered bycovered by endosteumendosteum
 Consists of a layer of loose connective tissue withConsists of a layer of loose connective tissue with
osteogenic cellsosteogenic cells
 Physically separates bone surface from thePhysically separates bone surface from the
marrow withinmarrow within

CANCELLOUS BONE
 CANCELLOUS BONE:CANCELLOUS BONE:
- large volume of soft tissue- large volume of soft tissue
space than bonespace than bone
matrixmatrix
- made up of bony plates or- made up of bony plates or
rods calledrods called
trabeculaetrabeculae
- trabeculae enclose wide- trabeculae enclose wide
spaces filled by bonespaces filled by bone
marrowmarrow
- lamellae, osteocytes &- lamellae, osteocytes &
canalicules similar tocanalicules similar to

(cont..)(cont..)
 BONE MARROW:BONE MARROW:
- F- Fills the medullary cavity in living boneills the medullary cavity in living bone
- Framework of reticular tissue- Framework of reticular tissue
- Reticular cell turn into osteoprogenitor cell- Reticular cell turn into osteoprogenitor cell
- Red marrow in child- Red marrow in child
- Yellow in adult - more of fat cells- Yellow in adult - more of fat cells

BONE CELLSBONE CELLS
 Two cell lineages each withTwo cell lineages each with
specific functions:specific functions:
1. Osteogenic cells – form &1. Osteogenic cells – form &
maintain bonemaintain bone
- osteoprogenitors,- osteoprogenitors,
preosteoblasts,preosteoblasts,
osteoblasts, osteocytes, boneosteoblasts, osteocytes, bone
lining cellslining cells
2. Osteoclasts – resorb bone2. Osteoclasts – resorb bone

BONE CELLSBONE CELLS (cont..)(cont..)
 BONE LINING CELLS:BONE LINING CELLS:
- inactive/postproliferative osteoblasts- inactive/postproliferative osteoblasts
- flat cells extending along bone surfaces- flat cells extending along bone surfaces
- primary site for mineral exchange- primary site for mineral exchange
between blood & bonebetween blood & bone

 OSTEOBLASTS:OSTEOBLASTS:
- large, nondividing cells that is polygonal or- large, nondividing cells that is polygonal or
slightly flattened in shapeslightly flattened in shape
- cytoplasm is deeply basophilic- cytoplasm is deeply basophilic
- nucleus is ovoid & eccentrically placed- nucleus is ovoid & eccentrically placed
- cytoplasmic processes are in contact with one- cytoplasmic processes are in contact with one
another & with processes of osteocytesanother & with processes of osteocytes
Functions:Functions:
- synthesize organic- synthesize organic
constituents of boneconstituents of bone
- participate in mineralisation- participate in mineralisation

 OSTEOCYTES:OSTEOCYTES:
- osteoblasts entrapped within- osteoblasts entrapped within
bone matrixbone matrix
Functions:Functions:
- maintain bone matrix- maintain bone matrix
- release calicum ions from- release calicum ions from
bone matrix during demandbone matrix during demand
- participate in local- participate in local
degradation of bonedegradation of bone
(osteocytic osteolysis)(osteocytic osteolysis)

 OSTEOCLASTS:OSTEOCLASTS:
- derived from monocyte-- derived from monocyte-
macrophage systemmacrophage system
- large, multinucleated- large, multinucleated
nondividing cellnondividing cell
- present within Howship’s- present within Howship’s
lacuna or resorptionlacuna or resorption
baysbays
- ruffled border & sealing zone- ruffled border & sealing zone

 OSTEOCLASTSOSTEOCLASTS - resorb bone- resorb bone
Sequence of resorptive events are:Sequence of resorptive events are:
1.1. Attachment of osteoclasts to bone surface viaAttachment of osteoclasts to bone surface via
integrinsintegrins
2.2. Creation of sealed acidic microenvironment – protonCreation of sealed acidic microenvironment – proton
pump – demineralizationpump – demineralization
3.3. Degradation of exposed matrix – acid phosphataseDegradation of exposed matrix – acid phosphatase
& cathepsin B& cathepsin B
4.4. Endocytosis of degradation products at ruffledEndocytosis of degradation products at ruffled
borderborder
5.5. Translocation & extracellular releaseTranslocation & extracellular release

 Regulators of bone resorption are:Regulators of bone resorption are:
1.1. Stimulators:Stimulators:
- parathyroid harmone- parathyroid harmone
- vitamin D- vitamin D
- interleukin 1, TNF- interleukin 1, TNF
- thyroid harmones- thyroid harmones
- TGF, EGF, FGF- TGF, EGF, FGF
- bacterial endotoxin- bacterial endotoxin
- thrombin, heparin- thrombin, heparin
- bradykinin- bradykinin www.indiandentalacademy.com

2. Inhibitors:2. Inhibitors:
- calcitonin- calcitonin
- interferon- interferon γγ
- glucocorticoids- glucocorticoids
- estrogen, androgens- estrogen, androgens
3. Possible agonits3. Possible agonits – effects not established– effects not established
- interleukin 6- interleukin 6
- M-CSF- M-CSF

Effect of hormones on boneEffect of hormones on bone
 Androgens, estrogens, and somatotrophin exert a definiteAndrogens, estrogens, and somatotrophin exert a definite
influence on growing boneinfluence on growing bone
 Parathyroid hormone has a direct action on bone it is responsibleParathyroid hormone has a direct action on bone it is responsible
for the maintenance of normal blood calciumfor the maintenance of normal blood calcium

1. Androgens, estrogens, and1. Androgens, estrogens, and
somatotrophin exert a definitesomatotrophin exert a definite
influence on growing boneinfluence on growing bone
2.2. Parathyroid hormone has aParathyroid hormone has a
direct action on bone it isdirect action on bone it is
responsible for theresponsible for the
maintenance of normal bloodmaintenance of normal blood
calciumcalcium
3.3. PTH secretion is controlledPTH secretion is controlled
by a negative feedbackby a negative feedback
mechanism.mechanism.
4. A fall in serum calcium4. A fall in serum calcium
stimulates the cells in thestimulates the cells in the
parathyroid gland to increaseparathyroid gland to increase
secretion of PTH, which insecretion of PTH, which in
turn stimulates target cells.turn stimulates target cells.
SystemicSystemic factors in alveolar bone lossfactors in alveolar bone loss ;; david.j.baylink jpd 1974 vol 31david.j.baylink jpd 1974 vol 31

Effect of vitamin on boneEffect of vitamin on bone
 Vitamin A( not proved totally)Vitamin A( not proved totally)
 Vitamin C; calcification depends on collagenVitamin C; calcification depends on collagen
production, deficiency is characterized by a decreasedproduction, deficiency is characterized by a decreased
activity of fibroblasts, osteoblasts, and odontoblastsactivity of fibroblasts, osteoblasts, and odontoblasts
 Vitamin D; the maintenance of normal plasma levels ofVitamin D; the maintenance of normal plasma levels of
calcium and phosphoruscalcium and phosphorus

 OSTEOCLASTOSTEOCLAST
DIFFERENTIATION:DIFFERENTIATION:

BONE REMODELLINGBONE REMODELLING
 Replacement of old bone by new is called boneReplacement of old bone by new is called bone
turnover or remodellingturnover or remodelling
 In healthy individual, this turnover is in a steadyIn healthy individual, this turnover is in a steady
state – amount of bone lost is balanced bystate – amount of bone lost is balanced by
formationformation

BONE REMODELLINGBONE REMODELLING (cont..)(cont..)
 Cemental/reversal lines:Cemental/reversal lines:
- deeply basophilic straight lines which- deeply basophilic straight lines which
indicate normal bone turnoverindicate normal bone turnover
- acts as cohesive mineralized layer- acts as cohesive mineralized layer
betweenbetween
old & new boneold & new bone
- indented cemental lines seen in- indented cemental lines seen in
acceleratedaccelerated
remodellingremodelling
e.g. Paget’s diseasee.g. Paget’s disease
 In osteoporosis & old age, resorptionIn osteoporosis & old age, resorption
exceeds formation – overall loss ofexceeds formation – overall loss of
bonebone

 The most common form of osteoporosis isThe most common form of osteoporosis is
known as “known as “primary osteoporosis.”primary osteoporosis.”
 It is the result of the cumulative impact of boneIt is the result of the cumulative impact of bone
loss and deterioration of bone structure asloss and deterioration of bone structure as
people age.people age.
 This bone loss can be minimized andThis bone loss can be minimized and
osteoporosis prevented through adequateosteoporosis prevented through adequate
nutrition, physical activity, and, if necessary,nutrition, physical activity, and, if necessary,
appropriate treatment.appropriate treatment.

Secondary osteoporosisSecondary osteoporosis

Bone disordersBone disorders
OsteodystrophyOsteodystrophy is defined as convenient term for boneis defined as convenient term for bone
diseases which are neither inflammatory nor neoplastic in nature,diseases which are neither inflammatory nor neoplastic in nature,
but which are genetic, metabolic or are of unknown cause.but which are genetic, metabolic or are of unknown cause.
Normal bone development requiresNormal bone development requires
 Formation of collagenous organic matrixFormation of collagenous organic matrix
 Deposition of bone salts (Calcium and phosphorus)Deposition of bone salts (Calcium and phosphorus)

Introduction…Introduction…
Normal bone development can be disturbed byNormal bone development can be disturbed by
 Intrinsic DefectsIntrinsic Defects
 Defect in bone matrix formation (scurvy)Defect in bone matrix formation (scurvy)
 Defect in mineralisation (rickets)Defect in mineralisation (rickets)
 Extrinsic DefectsExtrinsic Defects
 Deficiency diseases (calcium and phosphorous)Deficiency diseases (calcium and phosphorous)
 Endocrine disturbances (parathyroid)Endocrine disturbances (parathyroid)

Classification of OsteodystrophiesClassification of Osteodystrophies

Classification of OsteodystrophyClassification of Osteodystrophy
A. Genetic Disorders of BoneA. Genetic Disorders of Bone
1.1. Osteogenesis ImperfectaOsteogenesis Imperfecta
2.2. Marfan syndromeMarfan syndrome
3.3. OsteopetrosisOsteopetrosis
4.4. Cleidocranial DysplasiaCleidocranial Dysplasia
5.5. CherubismCherubism
6.6. Treacher Collins syndromeTreacher Collins syndrome
7.7. Tricho-dento-osseous syndromeTricho-dento-osseous syndrome
8.8. AchondroplasiaAchondroplasia
B. CraniosynostosisB. Craniosynostosis
1.1. Crouzon syndromeCrouzon syndrome
2.2. Apert syndromeApert syndrome www.indiandentalacademy.com

Classification of Osteodystrophy…Classification of Osteodystrophy…
C. Fibro-osseous LesionsC. Fibro-osseous Lesions
1.1. Fibrous DysplasiaFibrous Dysplasia
2.2. Cemento-osseous DysplasiaCemento-osseous Dysplasia
D. Metabolic Disorders of BoneD. Metabolic Disorders of Bone
1.1. RicketsRickets
2.2. ScurvyScurvy
3.3. HypophosphatasiaHypophosphatasia
E. Endocrine DisturbancesE. Endocrine Disturbances
1.1. HyperparathyriodismHyperparathyriodism
2.2. DwarfismDwarfism
3.3. GigantismGigantism
4.4. AcromegalyAcromegaly

Classification of Osteodystrophy…Classification of Osteodystrophy…
F. MucoploysaccharidosisF. Mucoploysaccharidosis
1.1. Hurler syndromeHurler syndrome
2.2. Hunter syndromeHunter syndrome
G. Renal OsteodystrophyG. Renal Osteodystrophy
1.1. OsteomalaciaOsteomalacia
2.2. OsteosclerosisOsteosclerosis
3.3. Osteitis FibrosaOsteitis Fibrosa
H. Bone pathology of unknown etiologyH. Bone pathology of unknown etiology
1.1. Paget’s DiseasePaget’s Disease
2.2. Massive OsteolysisMassive Osteolysis
3.3. Idiopathic OsteosclerosisIdiopathic Osteosclerosis
4.4. Pierre Robin syndromePierre Robin syndrome

Osteogenesis ImperfectaOsteogenesis Imperfecta

Osteogenesis ImperfectaOsteogenesis Imperfecta
 Heterogeneous group of heritable disordersHeterogeneous group of heritable disorders
characterized by impairment of collagen maturation,characterized by impairment of collagen maturation,
resulting in thin cortex, fine trabeculation and diffuseresulting in thin cortex, fine trabeculation and diffuse
osteoporosis.osteoporosis.
 Mainly inherited as AD (AR and sporadic cases hasMainly inherited as AD (AR and sporadic cases has
been reported).been reported).

Osteogenesis Imperfecta…Osteogenesis Imperfecta…
 Mutations in one of two genes that guide formation of type IMutations in one of two genes that guide formation of type I
collagen.collagen.
 COL1A1 = 17q21.3-q22.COL1A1 = 17q21.3-q22.
 COL1A2 = 7q22.1.COL1A2 = 7q22.1.
 Defect in cross linking of collagen molecules resulting in failureDefect in cross linking of collagen molecules resulting in failure
of fetal collagen to be transformed into mature collagen.of fetal collagen to be transformed into mature collagen.
 Calcification proceeds normally.Calcification proceeds normally.

Clinical FeaturesClinical Features
 Angulations and shortening of long bones – multiple fractures.Angulations and shortening of long bones – multiple fractures.
 Large head size with frontal and temporal bossngLarge head size with frontal and temporal bossng
 Blue scleraBlue sclera
 Xray of long bones show thin cortex with fine trabeculation andXray of long bones show thin cortex with fine trabeculation and
micro fractures.micro fractures.
 Wormian bonesWormian bones
 Oral ManifestationsOral Manifestations
 Class III malocclusion – maxillary hypoplasiaClass III malocclusion – maxillary hypoplasia
 Impacted teeth – 1Impacted teeth – 1stst
and 2and 2ndnd
molarsmolars
 Opalescent teethOpalescent teeth

Sillence, Senn and Danks classificationSillence, Senn and Danks classification
(1979)(1979)
Type IType I Type IIType II Type IIIType III Type IVType IV
Most common and mildestMost common and mildest
formform
Type I AType I A withoutwithout
opalescent teeth;opalescent teeth; Type I BType I B
associated with opalescentassociated with opalescent
teeth (DI is due to mutationteeth (DI is due to mutation
of DSPP gene 4q21.3)of DSPP gene 4q21.3)
Moderate bone fragilityModerate bone fragility
with 10% showingwith 10% showing
fracturesfractures at birth; 10%at birth; 10%
never show any fracture;never show any fracture;
frequency of fracture reducesfrequency of fracture reduces
after puberty.after puberty.
Blue scleraBlue sclera
Hearing lossHearing loss before thebefore the
age of 30age of 30
Hypermobility ofHypermobility of
JointsJoints (TMJ dysarthrosis)(TMJ dysarthrosis)
Easy bruisingEasy bruising
Most severeMost severe
form; 90% die atform; 90% die at
birth, rest withinbirth, rest within
4 weeks of age.4 weeks of age.
Extreme boneExtreme bone
fragility withfragility with
all casesall cases
showingshowing inin
uteroutero fractures.fractures.
Blue sclera.Blue sclera.
Moderately severe boneModerately severe bone
fragility; 50% showfragility; 50% show inin
uteroutero fractures.fractures.
Normal to pale blueNormal to pale blue
sclera; fades as the childsclera; fades as the child
grows.grows.
Hearing loss,Hearing loss,
hypermobility of joints,hypermobility of joints,
easy bruising.easy bruising.
Opalescent teeth may orOpalescent teeth may or
may not be present.may not be present.
Majority of affectedMajority of affected
individuals die duringindividuals die during
childhood due tochildhood due to
cardiopulmonarycardiopulmonary
complications.complications.
Mild to moderatelyMild to moderately
severe bone fragility.severe bone fragility.
50% show no50% show no
fractures at any timefractures at any time
of life.of life.
Normal to pale blueNormal to pale blue
sclera; fades as thesclera; fades as the
child grows.child grows.
Hearing loss and easyHearing loss and easy
bruising are rare.bruising are rare.
Opalescent teeth mayOpalescent teeth may
or may not be present.or may not be present.

 Type V, VI, VII has been reported, but theType V, VI, VII has been reported, but the
genetic causes has not been identified.genetic causes has not been identified.

TreatmentTreatment
No specific treatmentNo specific treatment

•Bone graft augmentation and dental implant treatment in a
patient with osteogenesis imperfecta: review of the literature
with a case report.
Lee CY, Ertel SK.
Implant Dent. 2003;12(4):291-5
•Dentofacial rehabilitation by osteodistraction,
augmentation and implantation despite
osteogenesis imperfecta.
Binger T, Rucker M, Spitzer WJ.
Int J Oral Maxillofac Surg. 2006 Jun;35(6):559-62.

OsteopetrosisOsteopetrosis

 Marble bone disease; Albers-Schonberg disease (GermanMarble bone disease; Albers-Schonberg disease (German
radiologist)radiologist)
 Exact molecular defect or site of mutation is not known.Exact molecular defect or site of mutation is not known.
 Marked increase in bone density due to failure of osteoclast toMarked increase in bone density due to failure of osteoclast to
resorb bone. Osteoclast number is normal but bone remodelingresorb bone. Osteoclast number is normal but bone remodeling
doesn't occur due to failure of osteoclast function.doesn't occur due to failure of osteoclast function.
 Clinically classified intoClinically classified into
 Infantile (malignant) osteopetrosisInfantile (malignant) osteopetrosis
 Adult (benign) osteopetrosisAdult (benign) osteopetrosis

Infantile (malignant)Infantile (malignant)
osteopetrosisosteopetrosis
Adult (benign) osteopetrosisAdult (benign) osteopetrosis
ARAR
At birth or early infancyAt birth or early infancy
Nasal stuffiness due toNasal stuffiness due to
mastoid and paranasalmastoid and paranasal
sinus malformation maysinus malformation may
be the earliest presentingbe the earliest presenting
complaint.complaint.
Diffuse sclerosis ofDiffuse sclerosis of
bone with growthbone with growth
retardation.retardation.
ADAD
Less severe manifestations; discovered later in life.Less severe manifestations; discovered later in life.
40% are asymptomatic; discovered as increased bone opacity on routine40% are asymptomatic; discovered as increased bone opacity on routine
radiographs.radiographs.
IntermediateIntermediate
TransientTransient
Less severe variant ofLess severe variant of
infantile osteopetrosisinfantile osteopetrosis
Asymptomatic atAsymptomatic at
birthbirth
Frequent fracturesFrequent fractures
after the 1after the 1stst
decade ofdecade of
lifelife
Marrow failure isMarrow failure is
AsymptomaticAsymptomatic
Diffuse sclerosis withDiffuse sclerosis with
marrow failuremarrow failure
Resolve withoutResolve without
specific therapyspecific therapy

Osteopetrosis…Osteopetrosis…
 Defective bone remodeling leads to obliteration ofDefective bone remodeling leads to obliteration of
marrow space, resulting in marrow failure andmarrow space, resulting in marrow failure and
pancytopenia.pancytopenia.
 Anemia leads to compensatory hepatosplenomegalyAnemia leads to compensatory hepatosplenomegaly
 Recurrent infections due to granulocytopeniaRecurrent infections due to granulocytopenia
 Easy bruising and bleeding due to thrombocytopeniaEasy bruising and bleeding due to thrombocytopenia
 Even though bone is thickened and sclerotic it has poorEven though bone is thickened and sclerotic it has poor
mechanical properties, and is fragile leading to frequentmechanical properties, and is fragile leading to frequent
pathological fractures (40%).pathological fractures (40%).www.indiandentalacademy.com

 Cranial nerve neuropathies due to compressionCranial nerve neuropathies due to compression
(narrowing of foramina) leads to blindness, deafness or(narrowing of foramina) leads to blindness, deafness or
facial palsy.facial palsy.
 Facial deformity – broad face, frontal bossing,Facial deformity – broad face, frontal bossing,
hypertelorism, snub nose.hypertelorism, snub nose.
 Delayed tooth eruption due to bone sclerosis.Delayed tooth eruption due to bone sclerosis.
 Osteomyelitis common after tooth extraction (10%).Osteomyelitis common after tooth extraction (10%).

RadiographicRadiographic
FeaturesFeatures
LaboratoryLaboratory
DiagnosisDiagnosis
HistopathologicHistopathologic
al Featuresal Features
Skull and jaws showSkull and jaws show
dense diffuse radiopacity.dense diffuse radiopacity.
Due to increasedDue to increased
density the roots of thedensity the roots of the
teeth are nearly invisible.teeth are nearly invisible.
Rugger-jersey sign –Rugger-jersey sign –
alternate bands ofalternate bands of
radio-dense and normalradio-dense and normal
bone densitybone density
appearance ofappearance of
vertebrae.vertebrae.
RBCs <1 millionRBCs <1 million
cmmcmm
Serum calcium,Serum calcium,
phosphorous andphosphorous and
alkaline phosphatasealkaline phosphatase
levels are normal;levels are normal;
acid phosphatase andacid phosphatase and
creatinine kinasecreatinine kinase
(CK-BB) are(CK-BB) are
elevated.elevated.
Abnormal endosteal boneAbnormal endosteal bone
formation.formation.
Cancellous bone is replaced byCancellous bone is replaced by
torturous lamellar bone.torturous lamellar bone.
Marrow spaces show globularMarrow spaces show globular
amorphous bone deposition.amorphous bone deposition.
Persistence of cartilaginousPersistence of cartilaginous
core in endochondrial bones.core in endochondrial bones.
Numerous osteoclast are seenNumerous osteoclast are seen
with no evidence of Howship’swith no evidence of Howship’s
lacunae.lacunae.

TreatmentTreatment
 Bone marrow transplantBone marrow transplant
 Interferon gamma 1b along with calcitriolInterferon gamma 1b along with calcitriol
 Corticosteriods; PTH; MCSFCorticosteriods; PTH; MCSF
 Administer antibiotics (lincomycin,Administer antibiotics (lincomycin,
fluoroquinolone) before extraction.fluoroquinolone) before extraction.

Cleidocranial DysplasiaCleidocranial Dysplasia

Cleidocranial DysplasiaCleidocranial Dysplasia
 AD; 40% cases represent spontaneous mutationAD; 40% cases represent spontaneous mutation
 Mutation in CBFa1 (core binding factor alpha -1) located on 6p21Mutation in CBFa1 (core binding factor alpha -1) located on 6p21
 Rearrangement in 8q22 and 6q has also been reportedRearrangement in 8q22 and 6q has also been reported
 Short statureShort stature
 10% shows absence of clavicle – unilateral or bilateral; 90% have10% shows absence of clavicle – unilateral or bilateral; 90% have
clavicle showing varying degree of hypoplasia and malformationclavicle showing varying degree of hypoplasia and malformation
 Narrow drooping shoulders with long neck; can approximateNarrow drooping shoulders with long neck; can approximate
shoulders in frontshoulders in front
 Arnold head – large globular head with frontal, parietal and occipitalArnold head – large globular head with frontal, parietal and occipital
bossingbossing
 Frontanelles may remain open till adulthood; wormian bonesFrontanelles may remain open till adulthood; wormian bones

Cleidocranial Dysplasia…Cleidocranial Dysplasia…
Oral ManifestationsOral Manifestations
 Maxillary hypoplasiaMaxillary hypoplasia
 Underdeveloped lacrimal and zygomatic bonesUnderdeveloped lacrimal and zygomatic bones
 High arched narrow palateHigh arched narrow palate
 Increased prevalence of cleft palateIncreased prevalence of cleft palate
 Retention of deciduous teeth with delayed or failure of eruption ofRetention of deciduous teeth with delayed or failure of eruption of
permanent teethpermanent teeth
Radiographic FeaturesRadiographic Features
 Numerous unerupted permanent and supernumerary teeth – lackNumerous unerupted permanent and supernumerary teeth – lack
cementumcementum
 Mandible shows increased bone density with narrow ramus andMandible shows increased bone density with narrow ramus and
pointed coronoid processpointed coronoid process

Cleidocranial Dysplasia…Cleidocranial Dysplasia…

TreatmentTreatment
 Multidisciplinary approach-Multidisciplinary approach-
 pedodontist,orthodontist,oral surgeon andpedodontist,orthodontist,oral surgeon and
prosthodontistprosthodontist

Bone grafting and osseointegratedBone grafting and osseointegrated implants in the treatment ofimplants in the treatment of
cleidocranial dysplasia.cleidocranial dysplasia.
Lombardas PLombardas P, Toothaker RW., Toothaker RW.
 Bone grafts and endosseous implants were usedBone grafts and endosseous implants were used
in the maxillary arch in an attempt to provide ain the maxillary arch in an attempt to provide a
retentive and esthetic overdenture for a youngretentive and esthetic overdenture for a young
patientpatient
Compend Contin Educ Dent. 1997 May;18(5):509-12, 514.Compend Contin Educ Dent. 1997 May;18(5):509-12, 514.

Cleidocranial dysplasia:
modern concepts of treatment and a report of an orthodontic resistant case
requiring a restorative solution.
- Butterworth C.
•A case is presented of a young boy with cleidocranial dysplasia,
whose multiple supernumerary teeth prevented the eruption of
most of his permanent teeth
• His maxillary incisor teeth failed to erupt following removal of
anterior supernumerary elements and orthodontic traction.
•Lack of abutment teeth and a difficult maxillary base made
prosthetic treatment almost impossible.
• A horseshoe acrylic denture retained by milled crowns bonded
to the deciduous canines and a maxillary first molar proved a
very successful restoration
Dent Update. 1999 Dec;26(10):458-62.

Treatment of a patient with cleidocranial dysplasia using
osseointegrated implants: a patient report.
Petropoulos VC, Balshi TJ, Balshi SF, Wolfinger GJ.
•This patient report describes the treatment of a 42-year-old woman with
cleidocranial dysplasia.
•Endosseous implants were used to restore the mandibular and maxillary
arches with fixed prostheses.
•Six implants were placed in the mandible and immediately loaded with an
acrylic resin fixed prosthesis.
• In the maxillary arch, 10 implants were submerged for 4 months prior to
functional loading.
•A transitional denture was relined and placed in the maxilla 10 days after
implant placement.
•Three months later, a definitive mandibular prosthesis was fabricated.
•The definitive maxillary restoration was delivered 6 months after surgery.
The most recent follow-up, 6 months after delivery, confirmed a
satisfactory treatment result to date
Int J Oral Maxillofac
Implants. 2004 Mar-Apr;19(2):282-7

Fibrous DysplasiaFibrous Dysplasia

Fibrous DysplasiaFibrous Dysplasia
 Not a hereditary diseaseNot a hereditary disease
 Mutation in GNAS1 (guanine nucleotide binding protein,Mutation in GNAS1 (guanine nucleotide binding protein, αα
stimulating activity polypeptide) located on 20q13.2stimulating activity polypeptide) located on 20q13.2
 Cause continuous activation of G-protein leading to overCause continuous activation of G-protein leading to over
production of cAMP.production of cAMP.
 Clinical severity depends on point in time mutation of GNAS1Clinical severity depends on point in time mutation of GNAS1
occursoccurs
 Early embryological life – osteoblast, melanocytes, endocrine cells areEarly embryological life – osteoblast, melanocytes, endocrine cells are
affectedaffected
 Later in life – osteoblast – multiple boneLater in life – osteoblast – multiple bone
 Post natal – mutated cells confined to one site – single bonePost natal – mutated cells confined to one site – single bone

Fibrous Dysplasia (FD)…Fibrous Dysplasia (FD)…
VariantsVariants
 Monostotic Fibrous Dysplasia – 80%Monostotic Fibrous Dysplasia – 80%
 Limited to a single boneLimited to a single bone
 Polyostotic Fibrous DysplasiaPolyostotic Fibrous Dysplasia
 Jaffe-Lichenstein syndrome – FD of bone + café-au-Jaffe-Lichenstein syndrome – FD of bone + café-au-
lait spotslait spots
 McCune-Albright syndrome – FD + café-au-laitMcCune-Albright syndrome – FD + café-au-lait
spots + endocrine disturbancesspots + endocrine disturbances

Monostotic Fibrous DysplasiaMonostotic Fibrous Dysplasia
 Age: 2Age: 2ndnd
decade; mean age – 30yrsdecade; mean age – 30yrs
 Gender: no predilectionGender: no predilection
 Site: ribs, femur, tibia, craniofacial bones (25%)Site: ribs, femur, tibia, craniofacial bones (25%)
 Maxilla along with zygoma, sphenoid or occiputMaxilla along with zygoma, sphenoid or occiput
 Slow growing asymptomatic swelling causing facial deformity ofSlow growing asymptomatic swelling causing facial deformity of
varying degrees.varying degrees.
 When maxilla involved obliteration of max. sinus is commonWhen maxilla involved obliteration of max. sinus is common
 Ground glass appearanceGround glass appearance
 Not well demarcated from normal adjacent boneNot well demarcated from normal adjacent bone
 Narrowing of PDL space with ill-defined lamina duraNarrowing of PDL space with ill-defined lamina dura
 Early lesion may appear radiolucent or mottledEarly lesion may appear radiolucent or mottled

Polyostotic Fibrous DysplasiaPolyostotic Fibrous Dysplasia
Jaffe-Lichenstein syndromeJaffe-Lichenstein syndrome
 Asymptomatic before 10yrs of ageAsymptomatic before 10yrs of age
 Most commonly affected are long bones – leg length discrepancy dueMost commonly affected are long bones – leg length discrepancy due
to multiple pathological fractures; bowed legsto multiple pathological fractures; bowed legs
 Upto 75% of the skeletal bones maybe involvedUpto 75% of the skeletal bones maybe involved
 Facial asymmetry when jaws involvedFacial asymmetry when jaws involved
 Café-au-lait spots – 50% casesCafé-au-lait spots – 50% cases
 Increased melanocytes in basal layer of skin/mucosaIncreased melanocytes in basal layer of skin/mucosa
 trunk, thighs, abdomen, buttocks, neck, oral mucosatrunk, thighs, abdomen, buttocks, neck, oral mucosa
 Irregular outlineIrregular outline
 Usually on same side as bone lesion and near midline of bodyUsually on same side as bone lesion and near midline of body
 May occur at birth and precede development of skeletal and endocrineMay occur at birth and precede development of skeletal and endocrine
abnormalitiesabnormalities

Polyostotic Fibrous DysplasiaPolyostotic Fibrous Dysplasia
McCune-Albright syndromeMcCune-Albright syndrome
 Fuller Aibright 1Fuller Aibright 1stst
described this syndrome in 1937described this syndrome in 1937
 Associated with endocrinopathies along with bone involvementAssociated with endocrinopathies along with bone involvement
and café-au-lait spotsand café-au-lait spots
 Sexual precocity – menstrual bleeding, breast development and pubic hairSexual precocity – menstrual bleeding, breast development and pubic hair
growth within 1growth within 1stst
few yrs of lifefew yrs of life
 Pituitary adenomasPituitary adenomas
 HyperthyroidismHyperthyroidism
 Maybe associated with intramuscular myxomas – Mazabraud’sMaybe associated with intramuscular myxomas – Mazabraud’s
syndromesyndrome

Fibrous Dysplasia…Fibrous Dysplasia…
Histopathological FeaturesHistopathological Features
 Irregularly shaped trabeculae of woven bone not connected toIrregularly shaped trabeculae of woven bone not connected to
each other in cellular, loosely arranged fibrous stroma –each other in cellular, loosely arranged fibrous stroma –
curvilinear or Chinese letter shapedcurvilinear or Chinese letter shaped
 Lesionl bone fuses directly to normal bone at periphery of lesionLesionl bone fuses directly to normal bone at periphery of lesion
 Bone trabeculae are not lined by osteoblast and are thought toBone trabeculae are not lined by osteoblast and are thought to
arise by metaplasiaarise by metaplasia
 Tiny calcified spherules may be seen rarelyTiny calcified spherules may be seen rarely
 Long standing lesion undergoes progressive maturation toLong standing lesion undergoes progressive maturation to
lamellar bonelamellar bone

TreatmentTreatment
 Most stop enlarging when skeletal maturation is reachedMost stop enlarging when skeletal maturation is reached
 Cosmetic surgery for large lesionsCosmetic surgery for large lesions
 25-50% show re-growth after cosmetic shaving; especially25-50% show re-growth after cosmetic shaving; especially
in younger patientsin younger patients
ComplicationsComplications
0.1 - 4% has shown malignant transformation0.1 - 4% has shown malignant transformation
 OsteosarcomaOsteosarcoma
 FibrosarcomaFibrosarcoma
 ChondrosarcomaChondrosarcoma
 LiposarcomaLiposarcoma
 Breast carcinomas (Females)Breast carcinomas (Females)

Dental characteristics of fibrous dysplasia and McCune-AlbrightDental characteristics of fibrous dysplasia and McCune-Albright
syndrome.syndrome.
Akintoye SOAkintoye SO,, Lee JSLee JS,, Feimster TFeimster T,, Booher SBooher S,, Brahim JBrahim J,, Kingman AKingman A,,
Riminucci MRiminucci M,, Robey PGRobey PG,, Collins MTCollins MT..
((Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Sep;96(3):275-82Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Sep;96(3):275-82))
Malocclusion (81%) and other prevalent dental anomalies (41%)Malocclusion (81%) and other prevalent dental anomalies (41%)
included tooth rotation, oligodontia, and taurodontism. Theincluded tooth rotation, oligodontia, and taurodontism. The
expansion of the maxilla or mandible by FD did not distort theexpansion of the maxilla or mandible by FD did not distort the
dental arch curvature, anddental arch curvature, and routine dental therapies such as extractions,routine dental therapies such as extractions,
restorations, and orthodontic treatment did not exacerbate FD lesionsrestorations, and orthodontic treatment did not exacerbate FD lesions

CherubismCherubism

CherubismCherubism
 AD inherited disease; sporadic cases have been reportedAD inherited disease; sporadic cases have been reported
 Mutation in 4p16Mutation in 4p16
 Age: 2-5 yrsAge: 2-5 yrs
 Gender: equal predilectionGender: equal predilection
 Site: Posterior mandible; all four quadrants maybe affectedSite: Posterior mandible; all four quadrants maybe affected
 Asymptomatic slow growing bilateral swelling in posteriorAsymptomatic slow growing bilateral swelling in posterior
mandible and / or maxilla – plump cheeked cherubsmandible and / or maxilla – plump cheeked cherubs
 May develop within 6months; stabiles by 10-12yrs; slowly regressMay develop within 6months; stabiles by 10-12yrs; slowly regress
after pubertyafter puberty

Cherubism…Cherubism…
Clinical Features…Clinical Features…
 Eyes upturned to heaven appearanceEyes upturned to heaven appearance
 eyeballs tilted upwards – involvement of infra orbital rim and flooreyeballs tilted upwards – involvement of infra orbital rim and floor
 Rim of sclera seen beneath iris – stretching of upper facial skin pulls lowerRim of sclera seen beneath iris – stretching of upper facial skin pulls lower
eyelid downwardseyelid downwards
 Cervical lymphadenopathyCervical lymphadenopathy
 Loss of vision / hearingLoss of vision / hearing
 V shaped palate with widened alveolar ridgesV shaped palate with widened alveolar ridges
 Premature loss of deciduous teeth and delayed or failure of eruptionPremature loss of deciduous teeth and delayed or failure of eruption
of teethof teeth
 Displacement of teethDisplacement of teeth

Arnott (1978) grading systemArnott (1978) grading system
 Grade I – involvement of both mandibular ramusGrade I – involvement of both mandibular ramus
 Grade II – involvement of both mandibular ramus and maxillaryGrade II – involvement of both mandibular ramus and maxillary
tuberositiestuberosities
 Grade III – involvement of whole maxilla and mandible exceptGrade III – involvement of whole maxilla and mandible except
coronoid and condylescoronoid and condyles
 Bilateral multilocular radiolucencyBilateral multilocular radiolucency
 Numerous unerupted teethNumerous unerupted teeth
 Teeth appear floating because of alveolar bone lossTeeth appear floating because of alveolar bone loss

 Fibro-vascular connective tissue with numerous small bloodFibro-vascular connective tissue with numerous small blood
vessels showing eosinophilic cuffingvessels showing eosinophilic cuffing
 Multinucleated giant cells (osteoclast)Multinucleated giant cells (osteoclast)
 Older resolving lesion show increased fibrous tissue, less giantOlder resolving lesion show increased fibrous tissue, less giant
cells, and new bone formationcells, and new bone formation
TreatmentTreatment
 Tends to becom static,and shows regression as patientTends to becom static,and shows regression as patient
approaches puberty.approaches puberty.
 Cosmetic surgery if deformity persists after growth completionCosmetic surgery if deformity persists after growth completionwww.indiandentalacademy.com

RicketsRickets

RicketsRickets
 Rickets is common term for any disorder affecting Vit. DRickets is common term for any disorder affecting Vit. D
metabolism, leading to derangement of Vit. D-calcium-metabolism, leading to derangement of Vit. D-calcium-
phosphate axis, resulting in failure of endochondralphosphate axis, resulting in failure of endochondral
calcification.calcification.
 Depending on derangement rickets can beDepending on derangement rickets can be
1.1. Vit. D Deficient RicketsVit. D Deficient Rickets
2.2. Adult Rickets (Osteomalacia)Adult Rickets (Osteomalacia)
3.3. Vit. D Resistant RicketsVit. D Resistant Rickets
4.4. Vit. D dependent Rickets (Renal Rickets)Vit. D dependent Rickets (Renal Rickets)

Vit. D MetabolismVit. D Metabolism
Dietary ergosterol
from vegetables
7 dehydrocholestrol
from acetyl-CoA
UV Light UV Light
Ergocalciferol (Vit. D2) Cholecalciferol (Vit. D3)
25 hydoxycholecalciferol
Hepatic 25 hydroxylase
Renal 1 α hydroxylase
1, 25 dihydrocholecalceferol
Increased Ca absorption from gut
Increased Ca re-absorption from kidney
Increased Ca deposition in bone

Vit. D deficient ricketsVit. D deficient rickets
 Deficiency of Vit. D in children – 400IU daily requirementDeficiency of Vit. D in children – 400IU daily requirement
 Growth retardationGrowth retardation
 Bowed legsBowed legs
 Enlarged jointsEnlarged joints
 Rachitic rosaryRachitic rosary
 Abnormal enamel & dentin formation – wide predentin zone,Abnormal enamel & dentin formation – wide predentin zone,
increased interglobular dentin; higher caries indexincreased interglobular dentin; higher caries index
 Delayed eruption of teethDelayed eruption of teeth
 MalocclusionMalocclusion

Adult Rickets (Osteomalacia)Adult Rickets (Osteomalacia)
 Deficiency of Vit. D in adults, leading toDeficiency of Vit. D in adults, leading to
reduced calcium absorptionreduced calcium absorption
 Most common in postmenopausal womenMost common in postmenopausal women
 Normal remodeling of bone, but due to CaNormal remodeling of bone, but due to Ca
deficiency bones are fragile – pelvisdeficiency bones are fragile – pelvis
 Increased susceptibility to fracturesIncreased susceptibility to fractures
 Radiographs of long bones may showRadiographs of long bones may show
longitudinal hairline fractureslongitudinal hairline fractureswww.indiandentalacademy.com

Vit. D resistant ricketsVit. D resistant rickets
 Inherited as X-linked dominant traitInherited as X-linked dominant trait
 Mutation in PHEX gene (phosphate regulating gene with endopeptidaseMutation in PHEX gene (phosphate regulating gene with endopeptidase
activity on X chromosome) which encodes for zinc metalloproteinase enzymeactivity on X chromosome) which encodes for zinc metalloproteinase enzyme
– precise mechanism unknown– precise mechanism unknown
 Males more affectedMales more affected
 Clinical symptoms of rickets but does not respond to therapeutic doses ofClinical symptoms of rickets but does not respond to therapeutic doses of
Vit. DVit. D
 Hyocalcemia and hypophosphatemia due to decreased absorption from gutHyocalcemia and hypophosphatemia due to decreased absorption from gut
and renal re-absorptionand renal re-absorption
 Short stature; bowed legsShort stature; bowed legs
 Large pulp horns extending to DEJ causing pulp exposure and periapicalLarge pulp horns extending to DEJ causing pulp exposure and periapical
infection in otherwise normal appearing teeth.infection in otherwise normal appearing teeth.

Vit.D dependent rickets (Renal Rickets)Vit.D dependent rickets (Renal Rickets)
 Rare AR conditionRare AR condition
 Chronic renal disease causing deficiency in 1Chronic renal disease causing deficiency in 1 αα
hydroxylase enzyme needed to convert 25hydroxylase enzyme needed to convert 25
hydoxycholecalciferol to 1,25hydoxycholecalciferol to 1,25
dihydoxycholecalciferoldihydoxycholecalciferol
 Patients respond to replacement therapy withPatients respond to replacement therapy with
calcitriolcalcitriol

HypophosphatasiaHypophosphatasia

HypophosphatasiaHypophosphatasia
 Rare inherited metabolic disease of bone (AR / AD).Rare inherited metabolic disease of bone (AR / AD).
 Deficiency of tissue-nonspecific alkaline phosphataseDeficiency of tissue-nonspecific alkaline phosphatase
(TNSALP).(TNSALP).
 Mutation in ALPL gene located at 1p36.1Mutation in ALPL gene located at 1p36.1
VariantsVariants
 PerinatalPerinatal
 InfantileInfantile
 ChildhoodChildhood
 AdultAdult
 Odonto-hypophosphatasiaOdonto-hypophosphatasia

Hypophosphatasia…Hypophosphatasia…
PerinatalPerinatal
 Most severeMost severe
 Diagnosed at birth and infant dies within hours due toDiagnosed at birth and infant dies within hours due to
respiratory failurerespiratory failure
InfantileInfantile
 Child appear normal till 6 months of age; show failure of growthChild appear normal till 6 months of age; show failure of growth
 Skeletal malformationSkeletal malformation
 Short bowed legs – short statureShort bowed legs – short stature
 Rachitic chest – respiratory failureRachitic chest – respiratory failure
 Craniosynostosis – increased intracranial pressureCraniosynostosis – increased intracranial pressure
 Hypercalcemia – renal stones; failureHypercalcemia – renal stones; failure

ChildhoodChildhood
 Child grows up to childhood without any symptomsChild grows up to childhood without any symptoms
 Delayed milestones – walking, speech, motor skillsDelayed milestones – walking, speech, motor skills
 CraniosynostosisCraniosynostosis
 Short stature, bowed legs, enlarged jointsShort stature, bowed legs, enlarged joints
 Premature loss of deciduous teeth – anterior teeth; alveolar bonePremature loss of deciduous teeth – anterior teeth; alveolar bone
loss; enlarged pulp chamberloss; enlarged pulp chamber
 Skull radiograph – uniformly placed, poorly defined, smallSkull radiograph – uniformly placed, poorly defined, small
radiolucencies – beaten copper appearanceradiolucencies – beaten copper appearance

AdultAdult
 Mildest form – symptom less till middle ageMildest form – symptom less till middle age
 Foot pain / thigh pain due to pseudo-fractures of metatarsals /Foot pain / thigh pain due to pseudo-fractures of metatarsals /
femurfemur
 Premature loss of deciduous and permanent teethPremature loss of deciduous and permanent teeth
Odonto-hypophosphatasiaOdonto-hypophosphatasia
 AsymptomaticAsymptomatic
 Premature loss of deciduous and permanent teethPremature loss of deciduous and permanent teeth

Laboratory DiagnosisLaboratory Diagnosis
 Serum calcium and phosphorous – normalSerum calcium and phosphorous – normal
 Serum alkaline phosphatase – decreasedSerum alkaline phosphatase – decreased
 Serum and urine phosphoethanolamine – elevatedSerum and urine phosphoethanolamine – elevated
 Normal bone or abundant woven boneNormal bone or abundant woven bone
 Osteoblast and osteoclast appear morphologically normal; noOsteoblast and osteoclast appear morphologically normal; no
Howship’s lacunaeHowship’s lacunae
 Increased width of proliferating cartilage; Numerous cartilageIncreased width of proliferating cartilage; Numerous cartilage
islands within marrowislands within marrow
 Reduced or absence of cementumReduced or absence of cementum

TreatmentTreatment
 Therapeutic measures unsuccessful.Therapeutic measures unsuccessful.
 High doses of phosphates results in moderateHigh doses of phosphates results in moderate
improvement.improvement.

Paget’s DiseasePaget’s Disease

Paget’s DiseasePaget’s Disease
 Abnormal resorption and deposition of bone, resulting inAbnormal resorption and deposition of bone, resulting in
distortion and weakening of affected bonesdistortion and weakening of affected bones
 Exact cause is unknownExact cause is unknown
 InflammatoryInflammatory
 GeneticGenetic
 EndocrineEndocrine
 Slow virus infection – paramyxovirusSlow virus infection – paramyxovirus
 VariantsVariants
 MonostoticMonostotic
 Polyostotic – most commonPolyostotic – most common

Paget’s Disease…Paget’s Disease…
 Age: older people; rare in patients younger than 40yrsAge: older people; rare in patients younger than 40yrs
 Gender: MaleGender: Male
 Site: lumbar vertebrae, pelvis, skull, femur, skullSite: lumbar vertebrae, pelvis, skull, femur, skull
 Jaws affected in 17% of casesJaws affected in 17% of cases
 Bone painBone pain
 Bowing deformity of weight bearing bones – simian stanceBowing deformity of weight bearing bones – simian stance
 Pagetic bone forms near joints and promotes osteoarthriticPagetic bone forms near joints and promotes osteoarthritic
changes – joint pain, limited mobilitychanges – joint pain, limited mobility

 Skull circumference will progressively increaseSkull circumference will progressively increase
 Cranial nerve compression leads to deafness or visualCranial nerve compression leads to deafness or visual
disturbancesdisturbances
 Maxilla more affected; cause enlargement of middle 3Maxilla more affected; cause enlargement of middle 3rdrd
of theof the
face – leontiasis osseaface – leontiasis ossea
 Nasal obstruction, obliterated sinus, deviated nasal septumNasal obstruction, obliterated sinus, deviated nasal septum
 Alveolar ridges enlarge symmetricallyAlveolar ridges enlarge symmetrically
 If dentulous – spacing between teethIf dentulous – spacing between teeth
 If edentulous – dentures no longer fitIf edentulous – dentures no longer fit
 Extractions maybe difficult due to hypercementosisExtractions maybe difficult due to hypercementosis
 Extensive hemorrhage due to increased vascularityExtensive hemorrhage due to increased vascularity
 Osteomyelitis in sclerotic phaseOsteomyelitis in sclerotic phase

 Decreased radio-density of bone; skull show large circumscribedDecreased radio-density of bone; skull show large circumscribed
areas of radiolucency – osteoporosis circumscriptaareas of radiolucency – osteoporosis circumscripta
 Alteration in tabecular pattern – cotton wool appearanceAlteration in tabecular pattern – cotton wool appearance
 Teeth show hypercementosisTeeth show hypercementosis
 Bone scintigraphy – entire mandible show marked uptake fromBone scintigraphy – entire mandible show marked uptake from
condyle to condyle - Lincoln’s sign or black beardcondyle to condyle - Lincoln’s sign or black beard

 Uncontrolled alternating resorption andUncontrolled alternating resorption and
deposition of bonedeposition of bone
 Basophilic reversal lines indicating junctionBasophilic reversal lines indicating junction
between alternating resorptive and formativebetween alternating resorptive and formative
phases of bone – mosaic or jigsaw patternphases of bone – mosaic or jigsaw pattern
 Numerous osteoblast and osteoclast in lacunaeNumerous osteoblast and osteoclast in lacunae
rim bone trabeculaerim bone trabeculae

Laboratory DiagnosisLaboratory Diagnosis
 Serum calcium and phosphorous levels are normalSerum calcium and phosphorous levels are normal
 Serum alkaline phosphatase levels are elevatedSerum alkaline phosphatase levels are elevated
 Bone resorption markersBone resorption markers
 Urinary hydroxyprolineUrinary hydroxyproline
 N-telopeptides assayN-telopeptides assay
 Pyridinoline cross-link assayPyridinoline cross-link assay
TreatmentTreatment
 Analgesics for bone painAnalgesics for bone pain
 Calcitonin and bisphonatesCalcitonin and bisphonates
 Dentures to be remade periodically to accommodate increase inDentures to be remade periodically to accommodate increase inwww.indiandentalacademy.com

PrognosisPrognosis
 < 1% show malignant transformation< 1% show malignant transformation
 Osteosarcoma of pelvis and lower extremities;Osteosarcoma of pelvis and lower extremities;
jaw ostesarcomas are rarejaw ostesarcomas are rare
 Associated with poor prognosisAssociated with poor prognosis

To conclude…To conclude…

References(cont..)References(cont..)
 Ham’s histology ; 9Ham’s histology ; 9thth
edition; David H. Cormackedition; David H. Cormack
 Textbook of human histology;Inderbir singhTextbook of human histology;Inderbir singh
 Color atlas of histology;2Color atlas of histology;2ndnd
edition;M.B.L.Craigmyleedition;M.B.L.Craigmyle
 Langman’s medical embryology;7Langman’s medical embryology;7thth
edition;T.W.Sadleredition;T.W.Sadler
 Wheater’s functional histology;B. young,J.W.HeathWheater’s functional histology;B. young,J.W.Heath
 Bone remodeling and its disorders;2Bone remodeling and its disorders;2ndnd
edition;Gregoryedition;Gregory
R. MundyR. Mundy
 www. eMedicine .comwww. eMedicine .com
 www.cytochemistry.netwww.cytochemistry.net
 www.bonehistologylab.comwww.bonehistologylab.com

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