This document discusses the prenatal and postnatal development of the maxilla and palate. During prenatal development, the maxilla forms from the maxillary prominences. The palate develops from the maxillary processes and palatal shelves. The palatal shelves initially grow vertically but then reorient horizontally and fuse in the midline. Postnatally, the maxilla grows through processes like displacement, growth at sutures, and surface remodeling. Displacement includes primary displacement from growth of structures like the maxillary tuberosity, and secondary displacement from growth of structures it is attached to like the cranial base. Growth occurs at sutures connecting the maxilla. Surface remodeling increases the size, shape

1. A.MAHESH KUMAR
PG 1ST year
Dept of PEDODONTICS

2. CONTENTS
1.Prenatal development of Maxilla & palate
 Embryonic development
 Meckel’s cartilage
 Development of palate
 Mechanism of palate elevation
 Palate remodeling
2.Post natal development of Maxilla & palate
 Displacement
 Remodeling
 Growth at sutures
 Growth in height , width & length
 Maxillary sinus
Reference

3. Growth definitions
 According to “TODD” “Growth is an increase in size.” &“Development is
progress towards maturity .”
 The self multiplication of living substance – JX Huxely
 Increase in size, change in proportion & progressive complexity.
- Krogman
 Entire series of sequential anatomic & physiological changes taking place
from the beginning of prenatal life to senility –Meredith
 Quantitative aspect of biologic development per unit of time-Mayers.
 Change in any morphological parameter, which is measurable-Moss.

4.  Growth and development of an individual can be
divided into:-
1) PRENATAL & POSTNATAL periods.
-The pre-natal period of development is a dynamic
phase in the development of a human being.
-During this period, the height increases by almost 5000
times as compared to only a threefold increase during
the post-natal period.
Embryonic phase

5. Pre natal period

6. Anatomy of Maxilla

7.  Around the 4th wk of intra-uterine life , the developing brain
and the pericardium forms two prominent bulges on the ventral
aspect of the embryo . These bulges are separated by the
primitive oral cavity or stomodeum.
 The floor of stomodeum is formed by the buccopharyngeal
membrane which separates it from the foregut.

8. 8

9. Development of maxilla

10. DEVELOPMENT OF MAXILLA
 Maxilla forms with in the maxillary prominences
 Ossification of maxilla occurs slightly later than in the mandible
 Primary ossification centre appears – 7th week
 Secondary centers
zygomatic,
orbitonasal,
nasopalatine .

11.  It lies in the angle formed by the infra orbital nerve
and anterior superior alveolar nerve , above the part of
the dental lamina from which the tooth germ
develops.
 Ossification spreads by
Bony trough formed for infra orbital nerve and
palatine process
 Maxillary sinus-16th week

12.  The pharyngeal arches are laid down on lateral and ventral
aspects of the cranial most part of the foregut which lies in
close approximation with the stomodeum
 Initially, there are 6 pharyngeal arches , but 5th usually
disappears as soon as it is formed and separated by 4 brachial
grooves.

13.  The first arch is called MANDIBULAR ARCH
 The second arch - HYOID ARCH

14. Meckel’s cartilage
 It is derived from the first branchial arch around the 41st-45th
day of intra- uterine life.
 Extends from the cartilaginous otic capsule to the symphysis
and provides a template for guiding the growth of the
mandible.

15. The mandibular arches of both the sides form the lateral
walls of the stomodeum
 The mandibular arch gives of a bud
from its dorsal end called the
Maxillary Process.
 The Maxillary Process grows ventro-
medio-cranial to the main part of the
Mandibular arch which is now called
the Mandibular Process.
15

16.  Thus at this stage the primitive mouth is
overlapped from above by the Fronto-nasal
Process, below by the Mandibular process and on
either side by the maxillary process
16

17.  The ectoderm overlying the
Fronto-nasal Process shows
bilateral localized thickenings
above the stomodeum. These
are called the Nasal Placodes.
 These placodes soon sink and
form the Nasal Pits.
17

18.  The formation of these Nasal
Pits divides the Fronto-nasal
process into two parts :
 a.The Medial nasal process
 b.The lateral nasal process
18

19.  The two mandibular processes grow
medially and fuse to form the lower
lip and lower jaw.
 As the Maxillary Process undergoes
growth the Fronto-nasal process
becomes narrow so that the two
Nasal Pits come closer.
 The line of fusion of Maxillary
Process and the Medial nasal
Process corresponds to the Naso-
lacrimal duct.
19

20.  The stomodaeum is thus
overlapped superiorly by the
fronto-nasal process.
 The mandibular arches of
both sides form the lateral
walls of the stomodaeum.
 The mandibular arch gives off
a bud from its dorsal end
called the “MAXILLARY
PROCESS”.
20

21. DEVELOPMENT OF PALATE
 The palate is formed by
contribution of the :
a. Maxillary process
b. Palatal shelves given off by the
maxillary process
c. Fronto-nasal process
21

22. Prenatal development -Palate
 Formation of primary and secondary palate
 Elevation of palatal shelves
 Fusion of palatal shelves
22

23. PALATOGENESIS 5-12 WEEKS
6-9 WEEKS IS CRITICAL
PALATE
PRIMARY SECONDARY
23

24. Primary palate
 Frontonasal process
Medial nasal
Mesenchyme
Wedge shaped mass
between internal surface
of maxillary prominencePrimary palate
24

25. Secondary palate
 Maxillary prominence
Two horizontal mesenchymal projections
Lateral palatine process
Fuse With each other
Primary palate
Nasal septum
Secondary palate
25

26. Secondary palate
 6th week– 2 lateral palatal shelves develops
 Secondary nasal septum grows
7th week– palatal shelves grow & lie vertically
26

27.  Sometimes during the seventh week of intrauterine
life, a transformation in the position of the palatal
shelves occurs. They change from a vertical to
horizontal position.
 This transformation is believed to take place within
hours. Various reasons are given to explain how this
transformation occurs. They are :
a. Alteration in biochemical and physical consistency of
the connective tissue of palatal shelves.
27

28.  b. Appearance of an intrinsic shelf area.
 c. Rapid differential mitotic activity.
d. Alteration in vasculature and blood supply to
the palatal shelves.
28

29.  8th week IUL
Stomodeum enlarge
Tongue drops
Vertically inclined palatal shelves -horizontal
Shelves contact each other in midline
By 12th week, fusion of palatal processes is complete
29

30. 30

31. Withdrawal of embryos face from
against the heart prominence by
uprighting of head facilitates jaw
opening
31

32. 32

33. 33

34. Elevation of palate
Nasal
septum
Palatal
shelves
tongue
Histological section
34

35. Theories of palatal shelf elevation
EXTRINSIC FORCES
Descent of tongue
Myoneural activity with in tongue
Shelves pushed up by tongue
Mouth opening reflexes
35

36. INTRINSIC FORCES
Hydration and polymerisation of intercellular substance
Differential growth on one side of palatal shelf
Turgor produced by build up of HYALURONIC ACID
SEROTONIN release from neural tissue.
Mesenchymal cell biosynthetic activity
Changing amounts of GLYCOSAMINOGLYCANS(GAG)
36

37. Palatal fusion
37

38.  The fronto-nasal process gives rise to the premaxillary
region while the palatal shelves form the rest of the
palate.
As the palatal shelves grow medially, their union is
prevented by the presence of the tongue. Thus initially the
developing palatal shelves grow vertically downwards
towards the floor of the mouth
38

39.  Sometimes during the seventh week of intrauterine
life, a transformation in the position of the palatal
shelves occurs.They change from a vertical to
horizontal position.
39

40. 40

41.  The two palatal shelves, by 8 ½ weeks of intrauterine
life , are in close approximation with each other.
Initially the two palatal shelves are covered by an
epithelial lining. As they join, the epithelial cells
degenerate.
The connective tissue of the palatal shelves
intermingle with each other resulting in their
fusion.
41

42.  The entire palate does not contact
and fuse at the same time. Initially
contact occurs in the central region
of the secondary palate posterior to
the premaxilla. From this point,
closure occurs both anteriorly and
posteriorly.
42

43.  The mesial edges of the palatal
processes fuse with the free lower
end of nasal septum and thus
separates the two nasal cavities from
each other and the oral cavity.
43

44. FUSION OF PALATAL SHELVES
 9-10 WEEK.
 EPETHLIUM THICKENS AND CONTACTS.
 ROLE OF GLYCOPROTEINS AND DESMOSOMES
 DEGENERATION OF EPITHELIUM.
 CONECTIVE TISSUE PENETRATION AND
INTERMINGLING.
 ENTIRE PALATE DOES NOT FUSE AT SAME
TIME, INTIAL CONTACT ,CENTRL REGION OF
SECONDARY PALATE, THEN CLOSURE
CONTINUES BOTH ANT. AND POSTERIORLY.
44

45. OSSIFICATION OF PALATE
• Ossification of the palate occurs from the 8th week of intra-
uterine life. This is an intramembranous type of ossification
• The palate ossifies from a single centre derived from the
maxilla
• The most posterior part of the palate does not ossify. This
forms the soft palate
• The mid palatal suture ossifies by 12-14 yrs

46. Post natal growth of maxilla

47.  Maxilla is a membranous bone and
development/growth of maxilla is completed early
when compared to mandible.
 Maxilla (especially width) also follows closely neural
growth curve more than the general growth curve in
scammon’s curve.
 Maxilla cannot be considered as a separate bone,it has
to be nasomaxillary complex because of close
association or attachment of maxilla to cranial base.
47

48.  The growth of the naso-maxillary complex is produced
by the following mechanisms :
• Displacement
• Growth at Sutures
• Surface Remodeling
48

49.  Two basic growth movements;
Drift(cortical remodelling);
Combination of simultaneous deposition and resorption
resulting in a growth movement towards the depositing
surface has been described as cortical drift by
Enlow(1963).
Dispacement ;movement of entire bone.
Classified as:
Primary
secondary
49

50.  DISPLACEMENT
 Maxilla is attached to the cranial base by means of number of
sutures, thus the growth of the cranial base has a strong
influence on the naso-maxillary growth.
 Primary displacement(translation) is the movement of bone
due to its own growth.
 A passive or Secondary Displacement of the naso-maxillary
complex occurs in a downward and forward direction as the
cranial base grows.
50

51.  Primary Displacement
is also seen in a forward
direction. This occurs by
growth of the maxillary
tuberosity in a posterior
direction. This results in the
whole maxilla being carried
anteriorly.
This is a primary type of displacement as the
bone is displaced by its own enlargement
51

52. The naso-maxillary complex is simply moved anteriorly as the
middle cranial fossa grows in that direction
SECONDARY DISPLACEMENT OF MAXILLA
52

53. Growth at sutures
 It is a complex system of sutures through which all the bones are in
contact.
 GROWTH AT SUTURE
 The maxilla is connected to the cranium and the cranial base by a
number of sutures.
 These sutures include :
 a. Fronto - nasal suture.
 b. Fronto – maxillary suture.
 c. Zygomatico – maxillary suture.
 d. Pterygo – palatine suture.
 e. Zygomatico – temporal suture
53

54. Sutural growth
54

55. 55

56.  Weinmann and sicher have pointed out that these
sutures are all oblique and more or less parallel to each
other. This allows the downward and forward
positioning of the maxilla as growth occurs at this
sutures.
56

57.  As the growth of the soft tissue occurs, the maxilla is
carried downward and forward. This leads to opening up
of space at the sutural attachments. New bone is formed
on either side of the suture.
 Thus overall size of the bones increases on either side.
Hence a tension related bone formation occurs at the
sutures.
57

58.  SURFACE REMODELING
 In addition to the growth occurring at the sutures,
massive remodeling by bone deposition and
resorption occurs to bring about :
• Increase in size.
• Change in shape of bone.
• Change in functional relationship
58

59.  Growth in height - vertical
 Growth in width - transverse
 Growth in length - A - P
59

60. HEIGHT
 ENLOW AND BANG ‘V’ PRINCIPLE
DEPOSITION ON THE
ORAL SIDE
RESORPTION ON
THE NASAL SIDE
60

61. APPOSITION IN
THE ALVEOLAR
PROCESS
ERUPTION OF
TEETH
61

62.  PRIMARY DISPLACEMENT
SUTURAL THEORY
CARTILAGENOUS THEORY
FUNCTIONAL MATRIX
HYPOTHESIS
62

63. SUTURAL THEORY
 SUTURES HAVE
INNATE GROWTH
POTENTIAL
 OBLIQUE NATURE
 SLIDING EFFECT
63

64. CARTILAGENOUS THEORY-SCOTT
 NASAL SEPTUM –INNATE GROWTH
POTENTIAL
 THRUST EFFECT– SEPTOPREMAXILLARY
LIGAMENT
 MORE ROLE IN A-P THAN VERTICAL
 SURGICAL REMOVAL OF NASAL SEPTUM
64

65. Removal of nasal septum –mid face
deficiency
65

66. FUNCTIONAL MATRIX HYPOTHESIS ---
MOSS
 SKELETAL UNITS FUNCTIONAL MATRIX
 BASAL BODY INFRAORBITAL
NERVE
 ORBITAL UNIT EYEBALL
 NASAL UNIT SEPTAL CARTILAGE
 ALVEOLAR UNIT TEETH
66

67. FUNCTIONAL MATRIX HYPOTHESIS
 REMODELING
CHANGES IN THE ORBIT
ENLARGING
ORO FACIAL
CAPSULE
67
Height

68. WIDTH
 Finished earlier in postnatal life,followed by depth and
height is achieved last.
 WIDTH GROWTH IN MID PALATINE suture
 REMODELING IN THE LATERAL SURFACE OF
ALVEOLAR PROCESS.
68

69.  Begins rapidly in the 2 nd year of life
Maxillary
tuberosity
Palato -
maxillary
suture
primary secondary
displacement
69

70. Remodelling pattern of anterior surface of maxilla
 Bone deposition seen at entire inner aspect
of maxillary arch & at tuberosity.
 At anterior concave surface of maxilla
periosteal concavity from ANS to point A is
depository and periosteal surface from point
A to alv.margin-resorptive.
 Reverse occurs in endosteal side of
cortex,upper half resorptive and lower half
depository.
 Key ridge-important site for reversal
&remodelling.
70

71. Maxillary tuberosity
 Established by the posterior limit of anterior cranial base .
This is called posterior maxillary plane(PM) plane.
 Deposition-posterior surface –increases length of arch-
room for erupting molars.
 Endosteal surface-resorptive-contributes to maxillary
sinus enlargement.
 Anterior displacement
 = posterior lengthening
71

72. Maxillary tuberosity
Tuberosity-major growth
site.
Cortical deposition at
these site pushes against
the posterior structures
with a counter anterior
thrust that leads to
primary displacement.
72

73. (Approximately first molar
region)Important site of reversal
and remodeling.
anterior surface of maxilla till the
region of key ridge – resorptive
,and concave ,facing downward
and growing inferiorly.
At region of key ridge-reversal
occurs-lateral surface of maxilla
posterior to key ridge & lateral
surface of tuberosity – depository ,
growing laterally facing upward.
73

74. All internal surfaces
resorption
[expect medial]-depository
this is selective remodelling
as compensation for laterallly
expanding nasal fossa.
Rapid continues downward
growth close proximity to
buccal maxillary teeth.
Maxillary sinus
74

75. Bone remodeling changes seen in
the Naso - maxillary complex
 Resorption occurs on the lateral surface of the orbital rim
leading to lateral movement of the of the eye ball. To
compensate, there is a bone deposition on the medial rim
of the orbit and on the external surface of the lateral rim.
75

76. 1)Bone deposition occurs
along the posterior margin
of the maxillary tuberosity.
This causes lengthening of the
dental arch and enlargement
of the antero- posterior
dimension of the entire
maxillary body.
This helps to accommodate the
erupting molars.
76

77. 77
 2) Bone resorption occurs on the
lateral wall of the nose leading to
an increase in the size of the nasal
cavity.
 3) Bone resorption is seen on the
floor of the nasal cavity. To
compensate there is a bone
deposition on the palatal side.
Thus a net downward shift occurs
leading to increase in maxillary
height.

78. 78
 4) The zygomatic bone moves in
a posterior direction. This is
achieved by resorption on the
anterior surface and deposition
on the posterior surface.
 5) The face enlarges in width by
bone formation on the lateral
surface of the zygomatic arch
and resorption on its medial
surface.

79.  6) The anterior nasal spine
prominence increases due to bone
deposition. In addition there is
resorption from the periosteal
surface of labial cortex. As a
compensatory mechanism, bone
deposition occurs on the endosteal
surface of the labial cortex and
periosteal surface of the lingual
cortex.
79

80.  7) As the teeth start erupting,
bone deposition occurs at the
alveolar margins. This
increases the maxillary
height and the depth of the
palate.
8) The entire wall of the maxillary sinus
except the medial wall undergoes
resorption. This results in increase in size
of the maxillary antrum.
80

81. 81
 9) Specifically mentioning, the vertical
growth of the maxillary complex is due to
the continued apposition of alveolar bone
on the free borders of the alveolar process
as the teeth erupt.
 10) Transversely, additive growth on the
free ends increases the distance and thus
the buccal segments move downward and
outward.
The expanding ‘V’
in the downward
and forward
growth of the
maxilla

82. Shift in circulation
 IMPORTANT SHIFT IN CIRCULATION IN THIS
REGION DURING CRITICAL TIME PERIOD OF
7-8 WEEK.
 6TH WEEK –STAPEDIAL ARTERY –ICA.
 7THWEEK –STAPEDIAL ARTERY SEVERES ITS
CONTACT WITH ICA.
 SAME TIME ITS BRANCHES TO MAXIILLA AND
MANDIBLE GETS ATTACHED TO ECA.
ICA ECA
82

83. Ossification of palate
 Ossification of the palate occurs from 8th week of intra-
uterine life.
 This is an Intramembranous type of an ossfication.
 The palate ossifies from a single center derived from
the maxilla.
 The most posterior part of the palate does not
ossify.This forms the Soft palate.
 The mid-palatal suture ossifies by 12-14 years.
83

84. Ossification of palate
 8th wk
10th wk
Premaxillary centres
Primary ossification centres of each palatine
bone
Y shaped midpalatal suture
Single ossification centre
– at junction of horizontal and perpendicular plates.
Mid-palatal suture is first evident at 10 1/2 weeks.
84

85. Musculature of palate
 Tensor veli palatini 40 days 1st arch
 Palatopharyngeous 45 days
 Levator veli palatini 8th week 2nd arch
 Palatoglossus 9th week
 Uvular muscle 9th week 2nd arch
85

86. Growth in dimensions-palate
 Pre natal life (appositional growth in the alveolar
margin)
length > width
 At birth (appositional growth in the maxillary
tuberosity)
length = width
 Post natal life
width > length
86

87.  Height
 Width Arched palate
Length
Length increases - 7-18 weeks IUL
Width increases - 4th month onwards
Lateral alveolar process together with a concave floor
produced by tongue – palatal tunnel to receive a nipple
Thumb and finger sucking- accentuated palatal furrow
87

88.  Growth at mid palatal suture ceases at 1-2 years
 Apposition
inferior surface
alveolar process
 Resorption –superior{nasal} surface
88

89. V principle of Bang and Enlow
 Remodeling of palate
Entire ‘v’ shaped
structure moves in a
direction towards the
wide end of the ‘v’
89

90.  Factors affecting growth of palate
Elevation of head and lower jaw
Oxygen and nutritional deficiency
Excess endocrine substances
Drugs
Irradiation
Vascularity
90

91.  Principles and practice of orthodontics –GRABER 3rd
edition.
 Textbook of craniofacial growth-sridhar premkumar .
 Contemporary orthodontics- PROFFIT,
 oral histology and embryology-orbans
 Craniofacial embryology- SPERBER.
 Text book of orthodontics – G singh.