This document discusses postnatal growth of the maxilla and mandible. It defines growth, development, and the different phases of postnatal growth. For the maxilla, it describes the key growth mechanisms including endosteal and periosteal growth, cortical drift, the "V" principle, and counterparts in other structures. Growth occurs primarily in width early, then length, and lastly height. For the mandible, it discusses growth from birth to 1 year involving the ramus, condyle and body, and remodeling that occurs after age 1. Matrix and intramatrix rotation influence mandibular growth. Anomalies that can affect growth are also summarized.

1. 1
POSTNATAL GROWTH
OF
MAXILLA AND MANDIBLE

2. Content
 Definitions
 Post natal growth of Maxilla
 Post natal growth of mandible
 Anomalies of growth
 Conclusion
 Bibliography
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3. 3
DEFINITIONS:
Growth:-
 According to TODD “Growth is an increase in size .
 According to SALZMANN “Growth is the
physiochemical process of living matter by which
organisms becomes larger”.
 J. S. HUXLEY “The self multiplication of living
substance”.

4. 4
DEVELOPMENT :-
TODD – “Development is a progress towards maturity”
MOYERS - “Development refers to all naturally occurring
unidirectional, changes in the life of an individual from
it’s existence as a single cell to it’s elaboration as a
multifunctional unit terminating in death”
Development = Growth + Differentiation + Translocation

5.  DIFFERENTIATION- It means change from
generalised cells to more specialised kind during
development.
 TRANSLOCATION- It means movement of cells
or tissues from one place to another as a result of
growth and development.
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6. POST NATAL GROWTH MEANS
 Growth occuring in first 20years of
life.
 Can be divided into3 phases
1) Infancy
2) childhood
3)Adolescence
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7. POST NATAL GROWTH OF
MAXILLA
7
Frontal process
Alveolar process
Zygomatic process
Body of maxilla
nasal notch
ANS
Infraorbital
foramen

8. Maxilla
 MAXILLA - cheek in Latin
 Parts of maxilla:
 Body
 zygomatic
 Frontal
 Alveolar
 Palatine
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9. 9
Key factors in growth of maxilla
 Endosteal & periosteal growth
 Cortical drift
 Relocation & remodeling
 The “V” principle
 Surface principle
 Growth field
 Displacement

10. 10
Endosteal & periosteal growth
 Half of the cortical plate of the facial & cranial
bone is formed by the outer surface i.e.
periosteum & other half by endosteum.

11. 11
Cortical drift
 TERMED by Enlow 1963
 Drift is growth movement of an enlarging portion of
bone by remodelling action of its osteogenic
tissues.
 It is brought about by combination of deposition
and resorption on the opposite side of the same
cortical plate.

12. 12

13. 13
“V” principle (Enlow1965)
 Areas grow by bone resorption on outer surface of
the V and bone deposition on the inner side.
 The V moves away from tip & enlarges
simultaneously .

14. Surface principle
 Bone side which face the direction of growth are
subjected to deposition and those opposite it
undergo resorption.
14

15. Concept of growth site and
growth center
Growth site:-any location or
place where growth takes place .
Eg: posterior border of ramus,
sutures, condyles, periosteum,
etc
Growth center:- –it has an
innate growth potential and do
not require the presence of
external stimulus for growth.
E.g.: Epiphyseal plates of long
bones and synchondroses of
basicranium
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16. DISPLACEMENT
 The movement of the whole bone as a unit,
in relation to each other or to a reference
point.
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17. 17
It occurs in the opposite
direction and deposition. parallel
to the direction of growth of the
bone, thus creating space into
which the bone can enlarge. The
degree of displacement equals
the amount of new bone
E.g. The movement of nasomaxillary
complex in the anterior and inferior
direction due to growth in posterior
superior direction.
PRIMARY DISPLACEMENT

18. 18
SECONDARY DISPLACEMENT :
Herein, the movement of the bone is
not directly related to its own
enlargement but by the growth of
the other bones and their soft
tissues.

19. Cranial base contribution
 The expansion at the cranial base has a major
secondary displacement effect on anterior cranial
fossa and nasomaxillary complex causing their
forward displacement.
 As the middle cranial fossa grows,it displaces
maxilla in an anterior and inferior direction.
 It is important growth mechanism till 6-7 years of
age.
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20. 20

21. GROWTH EQUIVALENT
CONCEPT/COUNTERPART
PRINCIPLE
According to Enlow, growth activity in one
region is invariably accompanied by
complementary growth in other regions.
 Thus if the anterior facial height is
long,facial balance is preserved,if posterior
facial height is also large.
 Short posterior height can lead to skeletal
open bite tendency.
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22. Different counterparts
 Nasomaxillary complex- anterior cranial fossa
 Horizontal dimension of pharyngeal space relates
to middle cranial fossa.
 Middle cranial fossa and breadth of ramus .
 Bony Maxilla and corpus of mandible.
 Maxillary tuberosity and lingual tuberosity.
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23. 23
SUTURAL GROWTH
 The sutural theory for bone growth was given by
Weinmann & Sicher in 1955.
 In the maxillary region, there are four main suture
sites.
a.) Fronto maxillary suture.
b.) Zygomatico maxillary suture.
c.) Zygomatico temporal suture.
d.) Pterygo palatine suture.
 Another suture which is of significant importance
is the mid palatine suture.

24. 24

25. 25
CARTILAGENOUS NASAL SEPTUM GROWTH
 Scott postulated that the cartilaginous nasal
septum is primarily responsible for the translation
of the facial bones, permitting growth of the mid-
facial region to proceed in a downward and
forward direction by the mechanism of surface
deposition of new bone matrix.
 The septal cartilage was presumed to act as a
pacemaker which regulates midfacial growth till
the eruption of the deciduous dentition is
completed.

26. ORBIT
 The floor of the orbit faces superiorly, laterally,
and slightly anteriorly. Surface deposition results
in growth proceeding in all three corresponding
directions.
 Resorption from the lateral surface of the orbital
rim functions to make way for the laterally moving
orbital surface of the maxilla in the floor of the
orbital cavity.

27. Remodelling resorption in different skeletal
units of maxilla

28. NASAL CAVITY
 The bony cortex lining the inner surface of the
nasal cavity undergoes periosteal surface removal of
bone as its endosteal side receives simultaneous
deposits of new bone.

29. PALATE
 The palatine processes of the maxilla grow in a
generally downward direction by a combination of
surface deposition on the entire oral side of the
palatal cortex with resorptive removal from the
opposite nasal side .

30. THE MAXILLARY TUBEROSITY
 Bone deposition occurs along the posterior margin
of maxillary tuberosity,causing lengthening of
dental arch.

31. 31
 There are three planes of space in maxilla
& there is a definitive sequence in which
growth is completed.
 Growth in width is completed first
 Growth in length
 Finally growth in height.
TIMING OF GROWTH

32. 32
POST NATAL GROWTH OF
MANDIBLE
 Mandible at birth
 From birth to 1st year of life
 After 1st year till adulthood

33. 33
PARTS OF MANDIBLE

34. 34
Mandible at birth
 At birth two rami of mandible are quite short ,
condylar development is minimal and there is
practically no Articular eminence in the glenoid
fossa.
 A thin line of fibro cartilage and connective tissue
exists at the midline of symphysis and this
cartilage is replaced by bone between 4th month
of age and the end of 1st year.

35. 35
 There is no significant growth between the two
halves before they unite.
 During 1st year of life appositional growth is
especially active at the alveolar border, at the
posterior and superior surfaces of Ramus ,at
condyle, along the lower border of the mandible
and on its lateral surfaces.

36. 36
From birth to 1st year of life
 Appositional growth especially active
at
 Alveolar border
 Distal and superior surface of Ramus
 Condyle
 Lower border of mandible
 Lateral surface of mandible
 After first year growth becomes selective,
remodeling and simultaneous displacement
in a forward and downward direction
proceeds from TMJ

37. 37
Post natal growth of Ramus
 Basic function of Ramus of mandible is that
it provides an attachment base for
masticatory muscles.
 As the mandible grows in length, the Ramus
is extensively remodeled , resorption
occurs at the anterior part of the Ramus
while deposition occurs on the posterior
region.

38. 38

39. 39
Corpus or the Body of mandible
 Body of the mandible grows longer as the Ramus
moves away from the chin by-
 Removal of bone from anterior surface of the
Ramus and deposition on the posterior surface.

40. 40

41. 41
The lingual tuberosity
 Lingual tuberosity is major growth remodeling site
and forms the boundary between the two basic
forms of the mandible : the Ramus and the corpus.
 The tuberosity remodels (relocates) in an almost
directly posterior direction by deposition on its
posteriorly facing surface.

42. 42

43. Coronoid process

45. Growth of condyle
 -Major site of mandibular growth.
 -Growth of condylar cartilage increases length &
height of mandible.

48. chin
 Growth of chin occurs at puberty as age advances.
 There is deposition of bone on anteroinferior
surface and resorption anterosuperiorly at level of
apices of roots of mandibular incisors.
48

49. Alveolar process
 Develops as the tooth erupts in response to
functional needs.
 Where there is partial anodontia,growth of
alveolar process is hampered.
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51. STAGES OF MAXILLARY &
MANDIBULAR GROWTH
1-5YRS 5-10YRS 10-20YRS
MAXILLA 45% 20% 35%
MANDIBLE 40% 25% 35%
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52. 52
Matrix rotation (rotation around the condyle)
it is seen when bite is opened by tooth eruption
or when excess vertical maxillary growth rotates
mandible downwards.
Intra matrix rotation (rotation centered
within the body of the mandible)
 Main contributor here is surface remodelling of
corpus.
 It contributes to development of angle of ramus,
prominence of chin.

53. MATRIX AND INTRAMATRIX
ROTATION
 matrix rotation
 intramatrix rotation
 intramatrix rotation53

54. Total rotation
 It is sum of both matrix + intramatrix rotation
 The two types of rotation may occur in same
direction or opposite direction.
 In most instances intramatrix rotation, accounts
for most of total rotation.
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55. 55
Bjork Solow
Houston
Profit
Rotation of mandibular
core relative to cranial
base
Total rotation True rotation Internal
Rotation
Rotation of mandibular
plane relative to cranial
base (Rotation around
the condyle
Matrix
Rotation
Apparent
Rotation
Total rotation
Rotation of mandibular
plane relative to core of
mandible (Rotation
centered within the
body of the mandible )
Intramatrix
Rotation
Angular
Remodeling of
lower border
External
Rotation

56. 56
 For an average individual with normal vertical
facial proportions
25% from matrix rotation
75% from intra matrix rotation

57. AGE CHANGES IN
MANDIBLE

60. 60
ANOMALIES OF GROWTH
ACHONDROPLASIA
Deficient growth at the synchondrosis
Maxilla is not translated forward
This results in abnormal depression of the bridge
of the nose

61. 61

62. 62
MAXILLARY DEFICIENCY:
 Both antero-posterior and vertical maxillary
deficiency can contribute to classIII
malocclusions.
MAXILLARY EXCESS:
 Excess growth of maxilla in children leads to a
skeletal class II malocclusion which has a vertical
as well as an antero-posterior component i.e. too
much downward and forward growth.

63. 63
TRANSVERSE MAXILLARY
CONSTRICTION:
 Skeletal maxillary constriction is distinguished by
a narrow palatal vault.
 It can be corrected by opening the mid-palatal
suture which widens the roof of the mouth and
floor of nose.
 The growth of this suture helps in arch-widening
and continues till late teens and then ceases

64.  MICROGNATHIA- Diminutive mandible.
 Seen in pierre robin, cri-du-chat
syndrome,treacher collin syndrome.
 MACROGNATHIA-usually an inherited
condition.
 Can occur due to abnormal growth phenomenon
such as hyperpituitarism.
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65. 65
CONCLUSION:
 In view of variability in growth of most facial
dimensions, detailed and accurate individualized
growth prediction is not possible.
 The best can be done is to base the treatment
planning on the existing facial pattern .

66. 66
Bibliography
 Text book of craniofacial growth first edition sridhar
prem kumar page no. 50-56
 .Diagnosis and management ofmalocclusion and
dentofacial deformities by om prakash kharbanda 2nd
edition page no.125-132
 Graber T.M :Orthodontics Principles And Practice,
Third ed., Philadelphia 1996, W.B. Saunders Company,
48-63,68,69,71
 . William R. Proffit: Contemporary orthodontics 4th
edition,elesevier2007 ; pg 29,44-46,111-118,127.
 . Samir E. Bishara: Textbook of orthodontics;1st ed,
Saunders Company2006, pg 45-60

67. 67
 .Bjork A : Prediction of mandibular growth
rotation. Am. J Orthodont1969, 55;589-599,.
 .Enlow, Harvold, Latham, Moffitt, Christiansen
and Hausch: Research on control of craniofacial
morphogenesis – AJO DO,1977 May (509 - 530):
 .Moss ML and Rankow R.M: The role of the
functional matrix in mandibular growth Angle
Orthodont 38:95-103, 1968.
 .Wagemans, van de Velde, and Kuijpers-Jagtman:
Sutures and forces- AJO DO Volume 94,NO 2:
Aug1988 (129 - 141):

68. THANK YOU
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