revathi growth & developmentof maxilla n mandible.ppt

growth and development of maxilla

2. GROWTH AND
DEVELOPMENT OF
MAXILLA AND MANDIBLE
AND RELATED AGE
CHANGES
Dr. K. Revathi

3. •INTRODUCTION
•TERMINOLOGIES
•THEORIESOFGROWTH
•ENLOW’SVPRINCIPLE
•TRAJECTORIESOFBONE
•OSSIFICATION----TYPES
•MAXILLA-PRENATALANDPOSTNATALDEVELOPMENT
•MANDIBLE-PRENATALANDPOSTNATALDEVELOPMENT
•DEVELOPMENTAL ANOMALIES
•DIFFERENCESANDSIMILARITIES
•AGECHANGES
•CONCLUSION
•REFERENCES

5. •Maxilla(upperjaw):anirregularlyshapedpairedbonethat
makesupamajorpartofthebonyframeworkofthefacial
skeleton.Consistsofbodyofmaxilla,thezygomatic,nasal,
palatine&alveolarprocess.
•Mandible(lowerjaw):consistsofacurvedhorizontalportion,the
body,andtwoperpendicualrportions,therami.Eachramus
carriesacoronoidandcondylarprocess.
•Growth:agerelatedincreaseinsizeormassinvolvingchangesin
amountoflivingsubstances.

6. Development:is considered the area of
differentiation and maturation that leads to increase in
skill, more comprehensive function and sexual
dimorphism in progress towards maturity.
Remodeling:is shaping of the outline of a bone by
selective resorption in some areas and apposition in
others.
Ossification:formation and development of bone is
termed ossification
Endochondral ossification:bone formation taking
place on a cartilage matrix, the cartilage immediately
preceding bone in development.

7. Intramembranous ossification:bone formation
directly within a connective tissue membrane
without any intermediate formation of cartilage.
Displacement:movement away from a certain
position or place.
Primary displacement:occurring in conjunction
with a bone’s own growth.
Secondary displacement:bone displacement
caused by enlargement of adjacent or remote
bones or tissues but not of bone itself.

8. Theories of growth

9. The Remodeling Theory Of Craniofacial
Growth
J.C.Brash (1930’s)
TheresearchbyBrashonboneprovidedthe
foundationforthedevelopmentofthefirst
generaltheoryofcraniofacialgrowth.

10. Genetic theory
•Growthiscontrolled
bygeneticinfluence
and is pre-
determined.

11. Sichers’ sutural theory
•Craniofacialgrowthoccursatsutures.
•Pairedparallelsuturesthatattachfacial
areastotheskullandcranialbaseregion
pushthenaso-maxillarycomplaex
forwardstoplaceitsgrowthwiththatof
mandible.

13. Functional matrix theory
ByMelvinMoss
Claimstheorigin,form,position,growthand
maintenanceofallskeletaltissuesandorgansare
alwayssecondaryresponsestopriorevents.
Independentfunctionsarecarriedoutinthe
cranio-facialregion.
Functionalcranialcomponentconsistsof:
Functionalmatrix
Skeletalunit

14. E.g. Coronoid –temporalis
Angular –Masseter and
medial pterygoid
Alveolar –Presence and
position of teeth.
Skeletal Units:

16. 1. The Neurocranial
capsule
2. The Orofacial
capsule

17. Van Limborgh theory
•Multifactorialtheory
•5factorscontrollinggrowth
•Intrinsicgeneticfactors
•Localepigeneticfactors
•Generalepigeneticfactors
•Localenvironmentalfactors
•Generalenvironmentalfactors.

19. Enlow’s V principle
•Manyfacialbones
haveavshaped
growthpattern.
•Regions include:
palate,bodyof
mandible,corronoid
process,condyle,
ramus.

21. Trajectories of bone
GivenbyBenninghoff.
Localandepigeneticfactorsresponsible
forfinalbonestructure.
Verticalpillarsinmaxilla:canine,
zygomaticandpterygoid
Mandible:coronoid,ramusandbody.

23. Types of ossification

24. Chondrogenesis
Chondroblasts produce matrix
Cells become encased in matrix
Chondrocytes enlarge, divide, and produce matrix
Matrix remains uncalcified
Membrane covers the surface but is not essential

25. Endochondral bone formation
Hypertrophy of chondrocytes and matrix calicifies
Invasion of blood vessels and connective tissue
cells
Osteoblast differentiate and produce osteoid tissue
Osteoid tissue calcifies
Membrane covers bone and is essential

26. INTRAMEMBRANOUS BONE
FORMATION
Osteoblast produce osteoid tissue
Cells and blood vessels are encased
Osteoid tissue is produced by membrane cells
Osteoid calcifies
Essential membrane covers bone

27. Theundifferentiatedmesenchymalcellsofthe
membranousconnectivetissuechangeto
osteoblastsandelaborateosteoidmatrix.The
matrixorintercelluarsubstancebecomescalcified
andboneresults.
Bone tissue laid down by
periosteum, endosteum, sutures,
and the periodontal membrane
are intramembranous in origin.

28. Herein, the formation of
bone is not preceded by
the formation of a
cartilaginous model.
Instead, bone is directly
laid down into a fibrous
membrane.
Intramembranousboneformationisthe
predominantwayofformationofboneintheskull.

30. MAXILLA

31. •Orbital
•Alveolar
•BasalBody
•Nasal
•Pneumatic
Developing elements of maxilla:

32. Maxillaarisesfromasinglecentreofossificationinthe
mesenchymeofthemaxillaryprocessofthe1
st
arch.
Noprimarycartilageexistsinthemaxillaryprocess.
The centre of ossification appears in theangle between the
division ofan nerve (i.e. where theanteriosuperior dental
nerveis given off from theinferior orbital nerve)just above
the canine tooth.
Pre-natal development of maxilla

33. Center of ossification

34. Spread of ossification

35. POST NATAL DEVELOPMENT OF
MAXILLA
Growthatthenaso-maxillarycomplexis
complex.
Mechanisminvolvedinplacingthemaxilla
forward
Growthatthesutures
Displacement
Surfaceremodelling

36. Growth at the sutures
Maxillaconnectedtocraniumbyfollowingsutures:
1.Frontonasal
2.Frontomaxillary
3.Zygomatico-temporal
4.Zygomatico-maxillary
5.Pteryopalatine
–Allthesesuturesareobliqueandparalleltoeachother.
–Growthatthesesuturesisgreatestuntilageof4
years.

38. Displacement

39. Displacement
•Movementofmaxillaintoananterior
positionoccursduetodisplacement
–Primarydisplacement
–Secondarydisplacement

40. Primary displacement

41. Secondary displacement

42. DEPOSITION AND RESORPTION

43. Surface remodeling
Massiveremodelingoccursi.e.,
depositionandresorptionbring
about:
•Increaseinsize
•Changeinshape
•Changeinfunctionalrelationship

44. Orbit and maxillary sinus

45. Maxillary tuberosity

46. Nose and Palate

47. Zygomatic bone

48. Development of mandible

49. Development of mandible
•Largestandstrongestboneofface.
•Undergoesconsiderableamountofchanges
amongthefacialbones.
•Itissecondbonetoossifyafterclavicle.
•Appearsasasingleboneinadult.
•Oneoftheunpairedbonesoffacialskeleton.

50. Prenatal Development of Mandible
•Derivedfromossificationofan
osteogenicmembraneat36to38days
ofdevelopment.
•At6
th
week,asingleossificationcenter
foreachhalfofmandiblearisesat
bifurcationofinferioralveolarnerve.

51. Center of ossification

53. Fate of Meckel’s cartilage
Posteriormostpartossifies
toform:malleus&incus.
Disappearsby24
th
week
afterconception
Partstransforminto:
sphenomandibular,
ant.malleolarligament.
Ventralendformsaccessory
endochondralossicles.

54. Between10
th
-14
th
weeks,
secondary accessory
cartilagesappeartoform
Headofcondyle
Partofcoronoid
process
Mentalprotruberance

55. Secondary cartilages
Cartilageofcoronoidprocess
developswithintemporalismuscle.
incorporatedintodevelopingramus.
disappearsbeforebirth.
Symphysealcartilage
1or2,mesialtoMeckelscartilage.
7
th
month,ossifiestoformmentalossicles.
incorporatedintosymphysismentiat1
st
postnatal
year.

56. 10
th
weeks-coneshapedinramalregion
14
th
weeks-endochondralboneformation
20
th
weeks(midfetallife)-completebonearticular
cartilagepersistsatupperend
121/2and14years(puberty)-condylargrowthrate
peaks
20
th
years-ceases
Specialproperty–potentialtogrow
Condylar cartilage

57. Thus, mandible is membrane bone developed in
relation to the nerve of the 1
st
arch& almost
independent of Meckel’s cartilage. The mandible has
neural, alveolar & muscular elements & its growth is
assisted by the development of secondary cartilages

58. Postnatal development of Mandible
•Mandibleundergoesthelargestamountofgrowth
post-natallyandalsoexhibitsthelargestvariability.
•Atbirth:Obtuseshape,Rudimentarycondyles
Ascendingramus–Low&wide
Coronoid–Large& projectsabove
thecondyle.
Body–OpenShell
MandibularCanal–Runslow.

59. Postnatal development of Mandible
The functional parts include-
Ramus
Corpus
Angle of mandible
Lingual tuberosity
The alveolar process
The chin

60. Corpus
•Asanteriorborderoframusresorbs–posterior
drift.
•Conversionofearlierramusintoposteriorpartof
thebody.
•Thusbodyofthemandiblelengthens.
•Growthofalveolarprocessincreasestheheight.

61. Ramus:
•Movesposteriorly;combinationofresorptionand
deposition
•Resorption–anteriorramuswhiledepositionposteriorly---
driftposteriorly
Functionsofremodeling-
•Accommodatetheincreasingmass
ofmasticatoryapparatus
•Enlargedbreadthofpharyngealspace
•Lengtheningofcorpus

62. Coronoidprocess
•FollowsVprinciple.
•Lingualsurface:deposition.
•Lengthensvertically-Vorientedvertically.

63. •Resorptiononbuccalsurface.

64. Angleofthemandible
•Lingualside-resorptionposterio-inferiorlywhile
depositionantero-superiorly.
•Buccalsideviceversa.
•Thisresultsinflaringofmandible.

65. Alveolarprocess
•Developsinresponsetotoothbuds.
•Asteetheruptthealveolarprocesserupt.
•Addsheight&thicknesstobodyofmandible.

66. Chin
•Aspecifichumancharacteristic;recentmanonly
•Asageadvancesthegrowthofchinbecomes
significant
•Sexualandgeneticfactors

67. Condyle
•Anatomicpartofspecialsignificance.
•Earlierthoughttobethemastercenter;nowa
regionalfieldofgrowth–regionaladaptive
growth

68. Mechanism
•Clearcutprocess
•Cartilageisspecialnon-vascular
tissue
•Secondarytypeofcartilage
•Endochondralmechanismofboneformation
duetovariablelevelsofcompression
•Proliferativeprocess–upwardand
backwardgrowthofcondyle

69. Height
•Ramusheightincreasescorrelatewithcorpus
lengthandheight.
•Alveolarprocessheight----eruption
•Anteriormandibularheightisrelatedtodental
developmentandoveralldownwardandforward
growthofmandible

70. Width
Bigonialandbicondylardiameterincrease–
divergenceofmandible.
Mostwidthincreasesasitgrowslonger(Enlow’sV
principle).
Length
Bycombinationofresorptionanddepositionatthe
ramus-corpusinterface.

71. Anomalies
1)Agnathia:mandible/maxillagrosslydeficient/
absent.
2)Macrognathia
3)Micrognathia
4) Facial hemihypertrophy

72. Developmental relation of maxilla & mandible
Fetal life:
•Initial–mandible>maxilla
•8
th
weeks–maxilla overlaps mandible
•11
th
weeks–approximately equal size
•13
th
–20
th
weeks–mandible lags behind
At birth:
•Mandible–Retrognathic, corrected early in post
natal life.

73. Similarities in maxilla and
mandible
Derivativesoffirstpharyngealarch.
Innervatedbyfifthcranialnerve.
Bothremodelpredominantlyinposterior
mannerandhencebecomedisplacedin
anantero-inferiormode

74. Differences between maxilla and
mandible
Mandibleisasinglebone,whereasnaso
maxillarycomplexisanelaborategrouping
ofmanyseparatebones.
Mandibleisamovablearticulationwithbasi
cranium,whilemaxillaisfixedwithcranial
floor.
Maxilla develops entirelyby
intramembranousossificationwhereas
mandibularcondyleexihibitsendochondral
ossification.

75. Maxillaryteethdriftinferiorly,mandibular
teethsuperiorly.
Positionofmandibularbodyisaresultof
functionofremodelingadjustmentand
alignmentofverticalheightandantero-
posteriordimensionsoframus,while
maxillaisplacedprimarilybybasi-cranium.

76. Age changes in maxilla &
mandible

77. MAXILLA
•Incisivepapilla:movesmoreclosetocrest
ofridge
•Maxilla:becomesinclinedinwards&
upwards
•Becomesprogressivelysmaller
•Supportareais24sq.cm.

79. MANDIBLE
ININFANTS&CHILDREN
Twohalvesofmandiblefuseatfirst
year.
Mentalforamen:opensbelowthe
socketsof2deciduousmolars.Nearer
tolowerborder.
Mandibularcanal:runsnearlower
border.
Gonialangle:obtuse.
Inferioralveolarforamen:

83. Conclusion….

84. References
CraniofacialDevelopment------Sperber
ContemporaryOrthodontics----Proffit
Essentialsoffacialgrowth---Enlow-Hans
Facialgrowth----Enlow–Poston
Tencate,soralhistologydevelopmentstructureandfunction-----
AntonioNanci
Humanembryology-----I.B.Singh.
Oraldevelopmentandhistology------JamesAvery.
Boucher,sprosthodontictreatmentforedentulouspatient------Zab
Bolender,Carlsson.
Prosthodonticsforelderly------Odont.
Gerodontology--------IanBarnes,AngusWall.
Oralanatomyhistoloyandembryology----Berkowitz.
OrthodonticsPracticeandPrinciples–TM.Graber.

86. Next seminar
•Surveyorandsurveyingprocedures…….
By
Dr.MayurAnand.
18.08.06