115
7/21/2019 1.Bone and Cartilage-final http://slidepdf.com/reader/full/1bone-and-cartilage-final 1/115 1 Good morning….

1.Bone and Cartilage-final

Embed Size (px)

DESCRIPTION

ppt

Citation preview

Page 1: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 1/115

1

Good morning….

Page 2: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 2/115

2

Bone And Cartilage  

By   Navya P.

Page 3: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 3/115

3

BONE

Page 4: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 4/115

In the evolutionary ladder bone is just young to cartilage

!uite young com"ared to a nerve and much younger than acell. Bone evolved just about #$$ millions years ago

in this %&$$ million years old earth

4

Page 5: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 5/115

'hen li(e began All li(eresided in the ocean .

Almost every creature"resent then )ould be)earing some sort o( an

e*ternal armor.

But this armor or

e*os+eleton)as o( either a mi*ture o("rotein , chitin or o( calciumcarbonate e*tracted (romsea )ater.

Ref: SCIENTIFIC AMERICAN; Understanding Origins: SEP 2009:Pg 75 5

Page 6: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 6/115

  -rue bone

It all started )ith (ishes.

6

Page 7: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 7/115

• -hus the /st evidence o( e*ternal bone )as about #%$

million years ago

• -he (irst to develo" internal bones then (ollo)ed.

• Eventhough evolved later bone no) is one o( the mostim"ortant o( its (unctions.

• -o us )ho are in the orthodontic (ield it matters evenmore.

7

Page 8: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 8/115

• Bone is a living tissue )hich ma+es u" the body

s+eleton and is one o( the hardest structure o( the

animal body.

• In an adult the s+eleton com"rises around /%0 o( the

total body )eight.

8

Page 9: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 9/115

• -he biggest bone in the body is the (emur and the

smallest is the sta"es bone in the middle ear.

• An adult human has around 1$& bones.

• -hese bones are organi2ed into a longitudinal a*is thea*ial s+eleton to )hich the a""endicular s+eleton is

attached

9

Page 10: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 10/115

AIA! S"E!ETON

It consists o( the 3$bones in the head andtrun+ o( the human body#

APPEN$ICU!AR S"E!ETON

Is com"osed o( /1& bones in the human body.

10

Page 11: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 11/115

 FUNCTIONS OF S"E!ETON SUPPORT 

•  4ha"e

•  Protection

•  Assisting In 5ovement

•  4torage O( 5inerals

•  Production O( Blood Cells

•  5aintenance O( Acid6base Balance

•  7eto*i(ication

-ransduction O( 4ound 11

Page 12: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 12/115

C8A44I9ICA-ION O9 BONE

BA4E7 ON -:EI; 4:APE8ong bones4hort bone9lat bone

Irregular bone4esamoid bone<Bones that develo" in s"eci(ictendons

BA4E7 ON -E=->;E O9 C;O44 4EC-ION

CorticalCancellous

12;e(? Orban@s Oral :istolo , Embr olo Edited b G.4.umar 5osb Elsevier /1th edt

Page 13: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 13/115

BA4E7 ON 5A-;I= A;;ANGE5EN- 8amellar

'ovenCom"actBundle

BA4E7 ON 5A->;I-Immature bone5ature bone

BA4E7 ON 7EDE8OP5EN-A8 O;IGIN

Intramembraneous boneIntracartilagenous bone

13;e(? Orban@s Oral :istology , Embryology Edited by G.4.umar 5osby Elsevier /1th edt

Page 14: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 14/115

Long bones

Short bones 14

Page 15: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 15/115

%ROSS STRUCTURE OF !ON% &ONE

-he gross structure o( a long bone can be divided intoseveral regions.

E"i"hysis? In the long bones the e"i"hysis is the regionbet)een the gro)th "late and the e*"anded end o( bonecovered by articular cartilage.

An e"i"hysis consists o( abundant trabecular bone and athin shell o( cortical bone.

15

Page 16: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 16/115

E"i"hysis is "resent at eachend o( the long limb bones.

•  It is (ound at only one endo( the 5etacar"als

metatarsals "halangesclavicles and ribs.

• -he e"i"hysis is the location

o( secondary ossi(icationcenters during develo"ment.

16

Page 17: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 17/115

5eta"hysis? -he junctional region bet)een the gro)th "lateand the dia"hysis.

-he meta"hysis contains abundant trabecular bone but thecortical bone thins here relative to the dia"hysis.

-his region is a common site (or many "rimary bone tumorsand similar lesions.

17

Page 18: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 18/115

7ia"hysis? -he dia"hysis is the sha(t o( long bones andis located in the region bet)een meta"hyses com"osed

mainly o( com"act cortical bone.

-he medullary canal contains marro) and a small amounto( trabecular bone.

Physis e"i"hyseal "late gro)th "lateF? -he "hysis is theregion that se"arates the e"i"hysis (rom themeta"hysis.

It is the 2one o( endochondral ossi(ication in an activelygro)ing bone or the e"i"hyseal scar

18

Page 19: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 19/115

9lat bone

• F'at ()nes are bones )hose "rinci"al (unction iseither e*tensive "rotection or the "rovision o(broad sur(aces (or muscular attachment.

•  -hese bones are e*"anded into broad (lat "latesas in the cranium.

19

Page 20: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 20/115

20

-hese bones are com"osed o( t)o thin layerso( com"act bone enclosing bet)een them a variable!uantity o( cancellous bone )hich is the location o(red bone marro)

In an adult most red blood cells are (ormed in (latbones.

9lat bones in human s+ull

Page 21: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 21/115

9lat bones

21

Irregular bones

Page 22: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 22/115

Irregular bones

• -he irregular bones are bones )hich (rom their"eculiar (orm cannot be grou"ed as long bone shortbone (lat bone or sesamoid bone

• Irregular bones serve various "ur"oses in the bodysuch as "rotection o( nervous tissue a((ordingmulti"le anchor "oints (or s+eletal attachment

maintaining "haryn* and trachea su""ortand tongue attachment.

22

Page 23: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 23/115

23

• -hey consist o( cancellous tissue enclosed )ithina thin layer o( com"act bone.

 Irregular bones can also be used (or joining all"arts o( the s"inal column together.

Irregular bones in human s+ull.

Page 24: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 24/115

 Cortical BoneHCom"act Bone H7ense Bone 

• It is one o( t)o main ty"es o( osseous tissue.

•  Cortical bone is dense and (orms the sur(ace o(bones.

• It is solid in a""earance and constitutes 3$0 o( totalbone mass.

24

Page 25: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 25/115

25

• Com"act bone is com"osed o( many cylinder sha"edunits called osteons or :aversian 4ystems and

transverse channels bet)een them called Dol+mannsCanal.

• -here are cavities inside com"act bones )here bone

marro) is stored.

Page 26: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 26/115

Cancellous Bone H4"ongy Bone H-rabecular

Bone • It is one o( t)o ty"es o( osseous tissue that

(orm bones. • Com"ared to com"act bone it has a higher

sur(ace area but is less dense so(ter )ea+erand less sti((.

• It ty"ically occurs at the ends o( long bones"ro*imal to joints and )ithin the interior o(vertebrae.

26

Page 27: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 27/115

27

• Cancellous bone is highly vascular and (re!uentlycontains red bone marro) )here hemato"oiesis the"roduction o( blood cells occurs.

•  -he "rimary anatomical and (unctional unit o(cancellous bone is the trabecula.

Page 28: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 28/115

28

8amellar Bone

• 5ature bone.

•  4trong highly organi2ed )ell minerali2ed tissue.

  5a+es u" more than JJ0 o( the adult humans+eleton.

• 9ull strength o( lamellar bone that su""orts anorthodontically moved tooth is not achieved untila""ro*imately / year a(ter com"letion o( activetreatment.

Page 29: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 29/115

29

 'oven Bone

It is ne)ly (ormed bone later re"laced by lamellarbone. In contrast to mature bone it does not have alamellar structure.

Bundles o( collagen (ibers run randomly in di((erentdirections interlacing )ith each other.:ence name)oven )eave (abric interlacing threadsF.

;elatively )ea+ disorgani2ed and "oorly minerali2ed.

Page 30: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 30/115

30

• Crucial role in )ound healing by

• ;a"idly (illing osseous de(ects.

• Provides initial continuity (or (ractures and

osteotomy segments.

• 4trengthening a bone )ea+ened by surgery or

trauma.

Ne)ly or (irst (ormed bone in res"onse to

orthodontic load.

Page 31: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 31/115

31

Com"osite Bone

• Osseous tissue (ormed by the de"osition o( lamellar

bone )ithin a )oven bone lattice a "rocess calledcancellous com"action.

 

Kuic+est means o( "roducing relatively strong bone.

• An im"ortant intermediary ty"e o( bone in "hysiologicres"onse to orthodontic loading.

• It usually is the "redominant osseous tissue (orstabili2ation during early "rocess o( retention.

Page 32: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 32/115

32

• Although the com"osite bone may be o( high !uality load

bearing osseous tissue is eventually remodeled into

secondary osteon.

;e(? -. 5 . Graber ;.8. Danarsdall orthodontics current "rinci"les and techni!ues Lrd edition

Page 33: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 33/115

33

 Bundle bone

• It is a (unctional ada"tation o( lamellar structure toallo) attatchment o( tendons and ligaments.

Per"endicular striations called 4har"ey (ibers are themajor distinguishing characteristics o( bundle bone.

• Bundle bone is the mechanism o( ligament and tendonattachment throughout the body

Page 34: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 34/115

34

Immature Bone Primary Bone -issueF

Immature bone is )oven bone.

5ature bone secondary bone tissueF

 5ature bone is characteristically lamellar bone.

 Almost all bones in adults are lamellar bones.

Page 35: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 35/115

35

Intramembranous Bone 5esenchymal BoneF

Intramembranous bone develo"s (rom directtrans(ormation o( condensed mesenchyme.

 9lat bones are (ormed in this )ay.

Intracartilaginous Bone Cartilage Bone EndochondralBoneF

Intracartilaginous bone (orms by re"lacing a

"re(ormed cartilage model.

8ong bones are (ormed in this )ay

Page 36: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 36/115

36

:istology o( bone 

• -he osteon is the (undamental (unctional unit o(com"act bone.

• Each osteon consists o( concentric layers or lamellaeo( com"act bone tissue that surround a central canal

the haversian canal.

•  -he haversian canal contains the bones nerve andblood su""lies.

Page 37: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 37/115

37

• -he boundary o( an osteon is the cement line.

• 4ome o( the osteoblasts develo" into osteocytes each

living )ithin its o)n small s"ace or lacuna.

• Osteocytes ma+e contact )ith cyto"lasmic "rocesseso( their counter"arts via a net)or+ o( small transverse

canals or canaliculi. -his net)or+ (acilitates thee*change o( nutrients and metabolic )aste.

•  Collagen (ibers in a "articular lamella run "arallel toeach other

• Osteons are connected to each other andthe "eriosteum by obli!ue channels called Dol+mannscanals.

Page 38: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 38/115

38

Parts O( Bone

Periosteum

Periosteum is the highly vascular membranous tissuecovering the bone that brings blood and lym"h vessels

as )ell as nerves to it .

 9unctions o( "eriosteum

Bone nutrition8ongitudinal and transverse gro)th o( bone;egeneration

Page 39: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 39/115

39

Periosteum has t)o layers

M E*ternal<(ibrous made o( dense irregular

connective tissue.

M Internal<cellular contains many osteoblasts andblood vessels some osteocytes as )ell.

Page 40: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 40/115

40

Endosteum

• It is a lining covering a bone (rom the marro) side

made o( loose irregular connective tissue )ithosteoblasts and osteoclasts in addition to morecommon cell ty"es o( this tissue.

It is a highly vascular condensation o( areolar tissuelining the various medullary s"aces

Page 41: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 41/115

41

Com"act bone 

• Consists o( dense de"osits o( minerals<chie(ly calcium"hos"hate and -y"e I collagen.

• -hese are arranged in concentric circles around acentral :aversian canal through )hich blood lym"h

vessels as )ell as nerves "ass through.

4"ongy bone

• -he mineral de"osits are arranged as a system o(struts.

•  Bone marro) (ills the s"aces bet)een.

Page 42: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 42/115

42

Bone marro)• 4ome bones such as the (emur also contain a central

cavity (illed )ith bone marro).

• Bone marro) contains the stem cells that give rise to allthe ty"es o( blood cells.

E"i"hyseal "late

• >ntil the end o( "uberty this dis+ o( cartilage "roducesmore cartilage )hich then is converted into bone.

• In this )ay the bone gro)s length)ise.

Page 43: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 43/115

43

4chematic re"resentation o( structure o( a ty"ical long bone

Page 44: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 44/115

44

Com"osition O( Bone

Cellular com"onents/$0F

OsteoblastOsteoclast

Osteocytes8ining cellsosteo"rogenitors

E*tracellular com"onentsJ$0F

OrganicL#0FGround substance

Collagen (ibers

Inorganic&#0FCalciumPhos"horous

4odiummagnesium

Page 45: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 45/115

45

Osteo"rogenitors

-hese are stem cells o( mesenchymal origin , they canconvert into osteoblast )hen ever there is a need.

• ;esemble young (ibroblasts.

• -hey are more in (etus at the site )here bone

(ormation is to ta+e "lace.

In adult they are "resent over both "eriosteal ,endosteal sur(aces.

Page 46: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 46/115

46

• Also "resent in "erichondrium

• -)o ty"es

• Committed osteo"rogenitor 6 di((erentiate into

"reosteoblasts6osteoblasts

• Inducible osteo"rogenitor may di((erentiate

into (ibroblasts myoblasts adi"ose cellschondroblasts etc

Page 47: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 47/115

47

Osteoblast

7erived (rom osteo"rogenitor cells o( mesenchymalorigin )hich are "resent in bone marro)

• Periosteum serves as the im"ortant reservoir o(osteoblasts es"ecially in gro)ing children.

• Are baso"hilic varied in sha"es oval triangularCuboidalF.

-hey are res"onsible (or synthesis de"osition andminerali2ation o( bone matri*

Page 48: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 48/115

48

Osteoclasts 

• Osteoclasts arise by (usion o( monocytes derived (rom

bone marro).

•  -y"e o( bone cell that removes bone tissue.

•  8arge cell %6/$$ m in diameter.

•  Numerous nuclei ? u" to 1$ or more.

•  Dariable in sha"e due to their motility.

Page 49: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 49/115

49

 Osteocyte

• -he osteocyte is estimated to ma+e u" more than J$0o( the bone cells in an adult s+eleton.

• -hey "lay an essential role in maintenance o( bone.

• 5ore in young decreasing )ith age.

Page 50: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 50/115

B 8i i C ll

Page 51: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 51/115

51

Bone 8ining Cells

• Bone lining cells are thin elongated cells that cover most

bone sur(acesE,PF in the mature s+eleton .

• Cyto"lasmic e*tensions or ga" junctions o(ten lin+ them

to each 

other or to osteocytes.

• 5etabolically inactive cells.

•  ;esting osteoblastsQ or Qsur(ace osteocytes.

Page 52: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 52/115

52

• In the "resence o( "arathyroid hormone these  cells

secrete en2ymes that remove the osteoid covering o( the 

bone matri* in "re"aration (or osteoclastic removal o(

bone.

• Bone lining cells may be "recursors  (or osteoblasts

regulate the crystal gro)th in bone or (unction  as a

barrier bet)een e*tracellular (luid and bone.

Page 53: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 53/115

53

Organic constituents

CO88AGEN

• -y"e I collagen (ibers about J#0F

-y"e D R#0• -he elasticity o( these im"arts ;E4I8IENC to the

tissue and hel"s to resist (racture.

.

Page 54: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 54/115

I i C tit t

Page 55: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 55/115

55

Inorganic Constituents

• Consists mainly hydro*ya"atite crystals )ith

carbonate content .

• :ydro*ya"atite crystals are thin "late or lea( li+estructure "ac+ed "arallel to collagen (ibrils.

• Ga"s bet)een crystals contains )ater and organicmolecules .

• 4mall amount o( calcium "hos"hate magnesium(luoride sodium "otassium (luoride iron 2inc etc.

• -hese minerals give bone its characteristic hardness and

Page 56: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 56/115

56

• -hese minerals give bone its characteristic hardness and

the ability to resist com"ression.

• Bone has to be #$0 minerali2ed to be seen in

radiogra"hs.

• Pea+ bone mass is reached bet)een ages 1$6L$ A(ter

this age bone loss begins.

• 3$0 o( the (actors that determine "ea+ bone mass are

genetic.

Page 57: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 57/115

57

BONE 7EDE8OP5EN- 

BONE 9O;5A-ION H O4-EOGENE4I4 H O44I9ICA-ION

Page 58: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 58/115

58

BONE 9O;5A-ION H O4-EOGENE4I4 H O44I9ICA-ION 

Bone (ormation occurs by three co6ordinated "rocesses?-he "roduction o( osteoid matri*-he maturation o( osteoid matri*5inerali2ation o( the matri*. 

In the embryo bone tissue arises through t)o "rocesses

Intramembraneous Endochondral

Page 59: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 59/115

59

• In both ossi(ication "rocesses "re6e*isting connectivetissue is re"laced by bone.

•  In intramembranous ossi(ication 6 some mesenchyme cellsare trans(ormed into osteoblasts and start laying do)nbone.

•-his is an ossi(ication "rocess that trans(orms membraneinto bone.

• Intramembraneous ossi(ication is seen in areas li+eCranial vault5a*illa5andible e*ce"t condylar cartilage

• Occurs in areas e*"osed to tension.

• In endochondral ossi(ication 6 a hyaline cartilage model o(

Page 60: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 60/115

60

In endochondral ossi(ication 6 a hyaline cartilage model o(the bone is ossi(ied.

Endochondral ossi(ication is the "rocess associated )ith(oetal bone develo"ment day6to6day bone gro)th and to acertain e*tent 6 (racture re"air.

•  -his is the ty"e o( bone (ormation (ound in

8ong bones such as the (emur and humerus4ynchondroses o( cranial baseCondylar cartilageNasal se"tal cartilage.

• Occurs in regions e*"osed to high level o( com"ression.

Page 61: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 61/115

61

• -hese t)o +inds o( ossi(ication do not lead to di((erencesin the structure o( mature bones.

• -hey sim"ly indicate di((erent methods a bone (ormation.

• Both mechanisms involve the re"lacement o( a "ree*istingconnective tissue )ith bone.

Page 62: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 62/115

62

• -he (irst stage in the develo"ment o( bone is themigration o( mesenchymal cellsembryonic connective

tissue cellsF into the area )here bone (ormation isabout to begin.

•  -hese cells increase in number and si2e.

•  In some s+eletal structures )here ca"illaries arelac+ing they become chondroblasts.

• -he C:ON7;OB8A4-4 )ill be res"onsible (orcartilage (ormation.

4-EP4 O9 IN-;A5E5B;ANO>4 O44I9ICA-ION

Page 63: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 63/115

63

4-EP4 O9 IN-;A5E5B;ANO>4 O44I9ICA-ION

/. 4elected mesenchymal cellscluster and (orm osteoblasts.

1. -his (orms an ossi(icationcenter.

L. Osteoblasts begin to secrete

osteoid )hich minerali2ed.%. -he osteoblasts are tra""ed

di((erentiate into osteocytes.

Page 64: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 64/115

64

#. Accumulating osteoid islaid do)n bet)een

embryonic blood vessels.&. -his (orms a net)or+ o(trabulae.

S. Dasculari2ed mesenchymecondenses on the e*ternal

sur(ace o( the )ovenbone and becomes the"eriosteum.

Page 65: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 65/115

65

3. -rabeculae just dee" tothe "eriosteum thic+en(orming a bone collar.

J. -he bony collar is laterre"laced )ith maturecom"act bone.

/$. 4"ongy bone consistingo( distinct trabeculaeare "resent internally.Blood vesselsdi((erentiate into redbone marro).

4-EP4 O9 EN7OC:ON7;A8 O44I9ICA-ION

Page 66: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 66/115

66

• Early in embryonic li(e a cartilage model or tem"late o(the (uture bone is laid do)n. -his model is covered by amembrane called the PE;IC:ON7;I>5.

• 5id)ay along the sha(t o( this model a blood vessel"enetrates the "erichondrium stimulating cells in the

internal layer o( the "erichondrium to enlarge andbecome osteoblasts.

• -he osteoblasts begin to (orm a collar o( com"act bone

around the middle o( the dia"hysis o( the cartilagemodel.

• Once the "erichondrium starts to (orm bone it is calledthe PE;IO4-E>5.

Page 67: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 67/115

67

/. -he "erichondriumcovering the hyalinecartilage model o(boneTis in(iltrated )ith bloodvessels.

1. Osteoblasts secreteosteoid against thehyaline cartilage

dia"hysis encasing it ina bony collar.

Page 68: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 68/115

68

L. Chondrocytes )ithin thedia"hysis hy"ertro"hyand signal thesurrounding cartilagematri* to calci(y.

%. -he chondrocytesho)ever die and the

matri* begins todeteriorate.

Page 69: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 69/115

69

#. In month L the

(orming cavities areinvaded by a collectiono( elements called the"eriosteal bud.

&. -he enteringosteoclasts "artiallyerode the calci(ied

cartilage matri*.

Page 70: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 70/115

70

S. Osteoblasts secreteosteoid around the

remaining (ragmentso( hyaline cartilage(orming trabeculae.

3. As the "rimaryossi(ication centerenlarges osteoclastsbrea+ do)n the ne)ly(ormed s"ongy bone

and o"en u" amedullary cavity in thecenter o( thedia"hysis.

Page 71: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 71/115

71

J. -he e"i"hyses remain(ormed o( cartilage until

shortly be(ore or a(terbirth.

/$. 4econdary ossi(icationcenters (orm in the

e"i"hyses. -he eventso( ossi(ication are li+ethe events o( thedia"hysis e*ce"t thats"ongy bone mains in theinternal and nomedullary cavity (orms.

Page 72: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 72/115

72

5inerali2ation 

-he matri* is initially laid do)n as unminerali2ed osteoid

• 5inerali2ation involves osteoblasts secreting vesiclescontaining al+aline "hos"hatase.

• -his cleaves the "hos"hate grou"s and acts as the (oci (orcalcium and "hos"hate de"osition.

• -he vesicles then ru"ture and act as a centre (or crystals

to gro) on.

Page 73: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 73/115

73

MEC*ANISM OF &ONE %RO+T*

-here are three basic mechanisms by )hich gro)th ta+es"lace at the cellularHtissue level. -hey are?

M :y"er"lasia ? Gro)th due to increase in number o( cells.

M :y"ertro"hy ? Gro)th due to increase in si2e o( the cells.

M E*tracellular 5atri* 4ecretion ? In this "rocess there 

is increase in si2e because o( the secretions o( thecells into the e*tracellular matri*

Post natal gro)th o( bone ta+es "lace in the (ollo)ing

Page 74: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 74/115

74

Post natal gro)th o( bone ta+es "lace in the (ollo)ingthree )ays?

M Chondral gro)th6achieved by interstitial gro)th o(cartilage originating in cartilage. E*am"le includessynchondroses.

M 4utural gro)th is a""ositional gro)th and occurs inthe s+ull and (acial sutures on the edge o( bones.

M Periosteal gro)th )hich is also a""ositional and occursin the "eriosteum. Periosteal gro)th unli+e the

chondral and sutural gro)th continues into advancedage.

Page 75: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 75/115

75

5EC:ANI45 O9 BONE G;O'-:

5odeling and remodeling7ri(t7is"lacement

Primary4econdary

-rabecular and cortical bone gro) ada"t and turn over bymeans o( t)o (undamentally distinct mechanisms modelingand remodeling.

Page 76: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 76/115

76

• Bone modeling is a mechanically mediated ada"tive"rocess (or changing a bones si2e sha"e or "osition.

• It is an uncou"led "rocess meaning anabolic and catabolicsites are controlled inde"endently.

• Its an im"ortant element o( s+eletal gro)th (unctions asa li(elong o"timi2ation "rocess (or ada"ting bone mass andarchitecture to (unctional needs.

• 5odeling also called as macro modeling by some authors is

an activity "rimarily (ound during gro)th and is res"onsible(or the (inal sha"e o( the bones.

Page 77: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 77/115

77

• Bone remodeling is the "hysiologic term (or internalturnover o( a minerali2ed tissue )ithout a change in its

overall (orm.

• It is a cou"led se!uence o( catabolic resor"tiveF andanabolic osteogenicF events to su""ort calcium homeostasisand re"air rene)F aged or damaged minerali2ed tissue.

Page 78: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 78/115

78

• Both modeling and remodeling are the result o( thecontrolled activity o( osteoblasts and osteoclasts.

• -he di((erence is in modeling both these t)o cells actover a large sur(ace area removing or (orming largevolumes o( bone mass )hich is active during gro)th "eriod.

• ;emodeling on the other hand is active throughout li(e and

serves to modi(y sha"e o( s+eleton architecture bonevolume and to re"air microdamage.

Page 79: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 79/115

79

+)'ff,s 'a- is a theory develo"ed by the German

anatomist and surgeon Uulius 'ol((/3L&/J$1F

It that states that bone in a healthy "erson or animal )illada"t to the loads under )hich it is "laced.

 I( loading on a "articular bone increases the bone )illremodel itsel( over time to become stronger to resist thatsort o( loading.

Page 80: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 80/115

80

-he internal architecture o( the trabeculae undergoes

ada"tive changes (ollo)ed by secondary changes to thee*ternal cortical "ortion o( the boneV "erha"s becomingthic+er as a result.

-he inverse is true as )ell? i( the loading on a bonedecreases the bone )ill become )ea+er due to turnover.

Page 81: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 81/115

81

• Cortical dri(t is gro)th movement relocation or

shi(tingF o( an enlarging "ortion o( a bone by theremodeling action o( its osteogenic tissues.

•   -he cortical "late can be relocated by simultaneousa""osition and resor"tion "rocesses on the o""osing

"eriosteal and endosteal sur(aces

• -he bony cortical "late dri(ts by de"ositing and resorbingbone substance on the outer and inner sur(aces

res"ectively in the direction o( gro)th.

• I( resor"tion and de"osition ta+e "lace at the same rate

Page 82: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 82/115

82

" " " the thic+ness o( the bone remains constant. i( more boneis de"osited than resorbed the thic+ness o( the structure

increases

• 7uring the develo"mental "eriod de"osition ta+es "lace ata slightly (aster rate than resor"tion so that the individualbones slo)ly enlarge.

7i l

Page 83: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 83/115

83

7is"lacement

• 7is"lacement is movement o( the )hole bone as a unit.

• It is a translatory movement o( the )hole bone caused bythe surrounding "hysical (orces and is the second

characteristic mechanism o( s+ull gro)th•  -)o ty"es

• Primary dis"lacement• 4econdary dis"lacement

Primary dis"lacement

Page 84: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 84/115

84

• As a bone enlarges it is simultaneously carried a)ay (romthe other bones in direct contact )ith it.

• -his creates s"ace )ithin )hich bony enlargement ta+es"lace.

 It is the "hysical movement o( the )hole bone as thebone gro)s and remodels by resor"tion and a""osition.

4econdary dis"lacement

Page 85: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 85/115

85

4econdary dis"lacement

•  It is the movement o( a )hole bone caused by the

se"arate enlargement o( other bones )hich may be nearbyor !uite distant.

• It is the movement o( bone related to enlargement o(

other bones. 

Page 86: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 86/115

86

  CA;-I8AGE

Page 87: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 87/115

87

Cartilage is a s"ecial ty"e o( connective tissue that has asti(( (irm but not hard intercellular matri*.

•  It "rovides rigid su""ort but it is so so(t that it can becut )ith a (ingernail.

• Cartilage is a nonvascular connective tissue and it isordinarily noncalci(ied.

• Cartilage is com"osed o( cells and an intercellular matri*containing (ibers and ground substance.

Page 88: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 88/115

88

9unctions o( cartilage

• 9le*ible su""ort in a""ro"riate anatomic "laces the nasal

ti" ear lobe thoracic cage tracheal ringsF

• Pressure tolerant tissue located in s"eci(ic s+eletal areas

)here direct "ressure occurs articular cartilageF

• Gro)th cartilage in conjunction )ith certain enlargingbones synchondrosis condylar cartilage e"i"hyseal "lateF.

Page 89: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 89/115

Inter cellular matri*

Page 90: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 90/115

90

• ;ich in "roteoglycans consisting o( a core "rotien6

+eratin sul(ate or chondrotin sul(ate )ith numerous

glycosaminoglycans attached around it in bottle brush

"attern

• Proteoglycans themselves are attatched by hyaluronic

acid.

Page 91: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 91/115

91

• Bet)een &$ and 3$ "ercent o( the net )eight o(

cartilage is )ater and this large com"onent o( )ateraccounts (or the resilient nature o( cartilage.

•  'ater is attracted to the negative charges in the

abundant sul(ate and carbo*yl grou"s on the GAGs.

• -his hydration "ermits di((usion o( )ater6solublemolecules in the ground substance.

Page 92: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 92/115

92

Perichondrium

• :as 1 layers?

  E*ternal 6 (ibrous made o(dense irregular connective

tissueInternal 6 cellularchondrogenicF contains many(ibroblasts and blood

• 9unctions?  cartilage nutritiona""ositional gro)th andregeneration

Page 93: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 93/115

93

Chondroblast

• 8ess di((erentiated cartilagecell

• Originate (rom non6

di((erentiated mesenchyme.

• :ave a (lattened sha"e

• A )ell6develo"ed roughendo"lasmic reticulum in abaso"hilic cyto"lasm Cb Chondroblasts

PC 6 Perichondrium

Chondrocyte

Page 94: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 94/115

94

Chondrocyte

•  Chondroblasts mature intochondrocytes

• 7i((erentiated cartilage cells

• 'ith advancing cellular agechondrocytes "rogressively losetheir rough endo"lasmicreticulum

• Chondrocytes reside in thede"th o( matri* 6 )ithin minutes"ecial cavities lacunaes

Page 95: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 95/115

95

-y"es o( cartilage

-here are three +inds o( cartilage de"ending u"on the

amount and nature o( (ibers in the connective tissue

  6 :yaline cartilage

  6 Elastic cartilage

  6 9ibro cartilage

:yaline cartilage

Page 96: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 96/115

96

:yaline cartilage

• 9ine collagen (ibers dis"ersed throughout the ground

substance

• 5ost abundant cartilage

• 9ound in joints )here it covers the ends o( bones

)ith a smooth sur(ace

• Involved in bone (ormation and gro)th

Page 97: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 97/115

97

• Amor"hous (irm matri* )ithim"erce"tible net)or+ o(collagen (ibers

• Chondrocytes lie in lacunae

• 4u""orts rein(orces cushionsand resists com"ression

• 9orms the costal cartilage

• 9ound in embryonic s+eletonend o( long bones nose tracheaand laryn*

El stic c til

Page 98: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 98/115

98

Elastic cartilage

• :as elastic (ibers

• Can be bent and then resume

  its original sha"e

• 9ound in the e*ternal ear and e"iglottis

4imilar to hyaline cartilage but )ith more elastic (ibers

• 5aintains sha"e and structure )hile allo)ing (le*ibility

9ibrocartilage• :as more collagen (ibers than hyaline cartilage

Page 99: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 99/115

99

• :as more collagen (ibers than hyaline cartilage

• 9ibers are organi2ed into bundles

• 9ound bet)een vertebrae in the +nee "ubic sym"hyses

-5U

• 5atri* similar to hyaline cartilage but less (irm )ith

thic+ collagen (ibers

• Provides tensile strength and absorbs com"ression shoc+

Page 100: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 100/115

100

Articular Cartilage

It is a s"ecialised (orm o( hyalinecartilage

• It is not surrounded by a"erichondrium and is "artly

vascularised

• -rans(orms the articulating endso( the bones into lubricated)ear6"roo( slightly com"ressible

sur(aces )hich e*hibit very little(riction

Page 101: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 101/115

101

-he main source o( nourishment(or articular cartilage is thesynovial (luid )hich (ills the

 joint cavity.

 Additional small amounts o(nutrients are derived (rom bloodvessels that course through thecalci(ied cartilage close to thebone.

Page 102: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 102/115

102

Primary Cartilage

• -hey are derivatives o( "rimordial cartilage.

•  In "rimary cartilage chondroblasts divide and

synthesi2e intercellular matri*.

• -he dividing chondroblasts are surrounded bycartilaginous matri*.

• Cells arranged in columnar (ashion

Page 103: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 103/115

103

• 4ince surrounded by cartilaginous matri* "rimarycartilage is not in(luenced by local environmental(actors.

• Gro)th is interstitial. :ence L dimensional gro)th

•  Considered to be a genetic "acema+er (or gro)th.

4econdary cartilage

Page 104: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 104/115

104

• 4econdary cartilage (orms on a membranous bone

•  No intercellular matri*

• Not surrounded by cartilaginous matri*

• Cells are arranged in ha"ha2ard manner

• A((ected by e*ternal in(luences )hich )ill stimulategro)th o( cartilage e.g. condylar cartilage

• Only "eri"heral gro)th ta+es "lace

• Contributes only to regional ada"tive gro)th

4 h d i

Page 105: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 105/115

105

4ynchondrosis

-he structure in the cranial base )hich resemblesthe gro)th "lates are synchondroses.

•  A synchondrosis is a ty"e o( immovable joint in

)hich the articulating structures are joinedtogether by hyaline cartilage.

• 4ynchondroses are (ormed bet)een the e"i"hysesendsF and dia"hyses sha(tsF o( long bones

Page 106: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 106/115

106

• It includes the numerous tem"orary cartilaginous junctions bet)een dia"hysis and e"i"hysis in the

immature "ost cranial s+eleton and also in theregions o( unossi(ied cartilage bet)een s+ullcom"onents develo"ing in the chondrocranium.

7iagrammatic re"resentation o(synchondrosis

Nasal Cartilage

Page 107: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 107/115

107

• Nasal cartilage is a thin cartilaginous "late located

bet)een vomer "er"endicular "late o( the ethmoid andnasal bone

• It "rovides a thrusting (orce )hich carries the ma*illa

(or)ard and do)n)ard during gro)th.

Cross section o( nasal cartilage

Condylar Cartilage

Page 108: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 108/115

108

Condylar Cartilage

-he condylar cartilage is a secondary ty"e o(cartilage )hich )as trans(ormed "hylogenetically(rom the "eriosteum

• -his cartilage is not a "art o( the 5ec+els cartilage

•   -he condylar cartilage gro)s not nterstitiallybuta""ositionally.

CARTI!A%E AN$ &ONE STRUCTURE COMPARE$#

Page 109: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 109/115

109

• Both o( these tissues re"resent s"eciali2ed s+eletalvariations o( ordinary connective tissue and theirres"ective (eatures sho) a number o( structuralsimilarities.

• Both are com"osed o( connective tissue cells )ith an

intercellular matri* containing collagenous (ibers andground substance.

•  -hey both have an enclosing vascular membrane and this

covering tissue is characteri2ed by a mar+ed gro)th"otential.

.

Page 110: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 110/115

110

• -he matrices o( cartilage and bone are rece"tive to

calci(ication although cartilage sho)s much variabilityin this regard.

• -he (irm rigidity o( both tissues is ada"ted to

(unctions o( su""ort

• Cartilage is noncalci(ied.

• Dascular canal system is lac+ing in cartilage direct

di((usion through its so(t matri* readily occurs.

Page 111: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 111/115

111

• E*trinsic "ressures may be involved in the many(unctional relationshi"s o( cartilage the lac+ o( blood

vessels )ithin this tissue is an ada"tation to the so(tnature o( its matri*.

• Bone in contrast has a calci(ied matri* housing a system

o( rigid6)alled vascular canals )ith their continuingelaborate net)or+ o( canalicular channels.

• Cartilage utili2es both a""ositional and interstitial"rocesses o( gro)th. Bone ho)ever can enlarge only by

an a""ositional mode o( gro)th

Page 112: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 112/115

112

Conclusion

Eugene ;oberts re(erred orthodontists ascranio(acial bone s"ecialists and hence a thorough+no)ledge about bone and cartilage )ill hel" theorthodontist to deal )ith the "atients moree((ectively and e((iciently.

;e(erences

Page 113: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 113/115

113

• 9acial gro)th?Enlo) Lrd edition

• Grays anatomy ?Lrd edition.

• Orban@s Oral :istology , Embryology /1th edt.

• -. 5 . Graber ;.8. Danarsdall orthodontics current"rinci"les and techni!ues Lrd edition

• -e*tboo+ o( cranio(acial gro)th 4ridhar Prem+umar

• 4cienti(ic american understanding origins? se" 1$$J?"gS#

Page 114: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 114/115

114

• :arold 5. 9rost A 1$$L u"date o( bone "hysiologyand )ol((@s la) (or cliniciansangle orthodontist vol

S% no / 1$$%

• '. Eugene roberts etal bone modeling? biomechanicsmolecular mechanisms and clinical "ers"ectives

seminars in orthodontics vol /$ no 1 juneF 1$$%? ""/1L6/&/

Page 115: 1.Bone and Cartilage-final

7/21/2019 1.Bone and Cartilage-final

http://slidepdf.com/reader/full/1bone-and-cartilage-final 115/115

-han+ you…………….