Department of Pedodontics and Preventive dentistry

1. GROWTH AND DEVELOPMENT
OF MAXILLA AND PALATE
-D. Shri Mahalakshmi
I year PG
Department of Peodontics and
Preventive Dentistry

2. CONTENTS
• Introduction
• Definitions
• Pre-organogenesis Period
• Embryonic Period
• Fetal period
– Pre natal development of maxilla
– Pre natal development of palate
• Postnatal development of maxilla
1. Displacement.
 Primary displacement.
 Secondary displacement.
2. Growth of sutures.
3. Surface remodeling.

3. • Postnatal development of palate
• Age changes
• Developmental anomalies
• Conclusion
• References

4. MAXILLA
• Maxilla is the second
largest bone in face,
first being mandible.
• Maxillae are a pair of
pneumatic bone that
houses the largest sinus
in the body- the
maxillary sinus.

5. PROCESSES OF MAXILLA

6. Definitions
• GROWTH :
Krogman (1950) – Increase in size, change in
proportion and progressive complexity.
Proffit (1986) –Increase in size or number.
Moyer(1988) -Change in any morphologic
parameter which is measurable.

7. DEVELOPMENT
Todd (1931) – Progress towards maturity.
Moyers (1988) – Naturally occurring
unidirectional changes in the life of an
individual from its existence as a single cell
to its elaboration as a multifunctional unit
terminating in death.

8. OSSIFICATION
INTRAMEMBRANOUS OSSIFICATION
• Bone laid down directly in a fibrous membrane
known as membrane bones and the process is
known as intramembranous ossification
ENDOCHONDRAL OSSIFICATION
• Bone formation is preceded by the formation of
cartilaginous model that closely resembles the bone
to be formed. This cartilage is subsequently
replaced by bone.

9. Pre-natal growth and development
• Divided into 3 periods
1) Period of ovum (fertilizaton - 2 weeks)
2) Embryonic Period (14th day - 56th day)
3) Foetal period (56th day - till birth)

10. PRE ORGANOGENESIS PERIOD EMBRYONIC PERIOD FOETAL PERIOD

11. PRE-ORGANOGENESIS PERIOD

13. EMBRYONIC PERIOD

14. Epiblast
Hypoblast
Hypoblast
Trophoblast

16. epiblast
hypoblast
hypoblast

17. EPIBLAST

20. The embryo at the completion of folding

21. PHARYNGEAL ARCHES

23. Structures seen in Pharyngeal arch

25. PHARYNGEAL ARCH DERIVATIVES

26. GENETICS
• Both maxillary and mandibular primordia
originate from similar NCCs and possess
similar molecular features, they develop into a
different structural entities.
• A gradient of gene expression the Dlx family of
transcription factors promotes and regulates
jaw patterning.
• Maxilla (Dlx1/2) and Mandible (Dlx1/2/5/6).

27. FOETAL PERIOD

28. PRE-NATAL EMBYOLOGY OF
MAXILLA

29. AROUND 4TH WEEK IUL

30. At the beginning of 5th week
• At this time cartilaginous septum is being
constructed from the mesenchymal cells of
the frontal prominence and medial nasal
process.
• The medial nasal process and the maxillary
process grows towards each other and are
almost in contact.

31. During 6th week
• Centre of ossification appears and is
associated closely with the cartilage of nasal
capsule.
• No primary cartilage exists.

32. PRIMARY OSSIFICATION CENTRE

33. • Secondary cartilage – Malar cartilage.
• The fusion of the maxillary process occurs in 14.5
mm embryo during the seventh week.

34. Between eighth and twelfth weeks
• The foetus triples in length from 20 to 60 mm.
• The maxillary sinus starts first at 10 weeks
post conception, appears as a shallow groove
near the middle meatus on the medial surface
of maxilla.

35. In the last half of fetal period
• The maxilla increases in height through bone
growth between the orbital and the alveolar
regions.
• As a result of medial growth of maxillary
prominences, the two medial nasal
prominences merge not only at surface but
also at deeper level.

36. • The structures formed by two merged
prominences is the intermaxillary segment.

37. PRE-NATAL EMBRYOLOGY OF
PALATE

38. • Primary palate – primary anterior mesenchymal
mass extends posteriorly from intermaxillary
process.
• Secondary palate – paired lateral palatine
process arises as a medial mesenchymal
projections from each maxillary process.
• Palatogenesis is concerned with two main
events.
• Palatal shelf elevation.
• Fusion of palatal shelves.

40. Drawings from below show the development of the palate from 6 to 7 weeks (A), 7 to 8 weeks
(B), and 8 to 10 weeks (C).

41. Fusion of palatal shelves

42. SOFT PALATE
• The most posterior part of the palate does not
ossify and remains as soft palate.
• Myogenic mesenchymal tissues of the first
and fourth pharyngeal arches migrates into
this faucial region, supplying the musculature
of the soft palate and fauces.

43. Muscles of Soft Palate

44. AT BIRTH

46. POST-NATAL DEVELOPMENT OF
MAXILLA

47. • The upper face under the influence of cranial base moves
upwards and forwards.
• The lower face moves downwards and forwards on an
“expanding V principle”.

48. • Growth of nasomaxillary complex is produced
by following three mechanisms
1. Displacement.
 Primary displacement.
 Secondary displacement.
2. Growth of sutures.
3. Surface remodeling.

49. PRIMARY DISPLACEMENT
Posterior directional
movement due to
growth in maxillary
tuberosity causes
maxilla to move
anteriorly.

50. PRIMARY DISPLACEMENT :
• Enlow and bang apply the principle of
“area relocation” to the complex and
multidirectional growth movements.
• As the dynamic process continues, “specific
local areas come to occupy new actual
position in succession, as the entire bone
enlarges.
• These growth shifts and changes involve
corresponding and sequential remodeling
adjustments in order to maintain the same
shape, relative position and constant
proportions of each individual area in the
maxilla as a whole”.

51. • Secondary displacement :
As the cranial base grows, it exerts
pressure on the nasomaxillary complex
displacing it in a downward and forward
direction.

52. GROWTH OF SUTURES
• Maxilla is attached to cranium by sutures which are
oblique and more or less parallel to each other.
• The 4 main sutures are :-
Frontomaxillary suture
Zygomatico-temporal suture
Zygomatico-maxillary suture
Pterygopalatine suture

54. SURFACE REMODELING
• Surface remodeling by bone deposition and
resorption occurs to bring about :
1. Increase in size
2. Change in shape of bone
3. Change in functional relationship

56. DEVELOPMENT OF MAXILLARY SINUS

57. POST NATAL GROWTH OF PALATE

58. • The appositional
growth of the alveolar
processes contributes
to the deepening and
widening of the vault
of the bony palate,
• Adding to the height
and breadth of the
maxillae at the same
time.

59. • The lateral alveolar processes help to form an
anteroposterior palatal furrow, which is ideally
suited to receive a nipple.
• The palatal furrow is well marked during the
1st year of life (i.e., the active suckling period)
• It normally flattens out into the palatal arch
after 3 to 4 years of age when suckling has
been discontinued.

60. AGE CHANGES

61. DEVELOPMENTAL ANOMALIES

62. • Cleft lip :
Defective fusion of the medial nasal process
with the maxillary process.
Types :
• Central.
• Lateral.
• Simple or compound.
• Complete or incomplete.

63. Cleft palate

64. Treacher Collins syndrome

65. • Pierre Robin sequence :
• Cleft palate
• Mandibular micrognathia
• Glossoptosis
• Van der Woude syndrome :
lower lip pits
cleft lip with or without cleft palate or
cleft palate alone

66. • Palatal cysts of the newborn :
Epstein’s pearls
Common finding on the palate of newborn.
As the palatal shelves meet and fuse in the
midline during embrynic life to form the secondary
palate, small islands of epithelium may become
entrapped below the surface along the median
palatal raphe and form cysts.

67. • Bohs nodules
• Keratin filled cysts found at the junction of
had and soft palate and along the buccal and
lingual parts of the alveolar ridges away from
the midline, and the remnants of salivary
glands.

68. CONCLUSION
• It is important for the clinician to know the
normal and the abnormal ranges of growth for
proper diagnosis, treatment planning and
selecting appropriate clinical procedures.

69. • REFERENCES:
1. Craniofacial development, Sperber.
2. Textbook of Pediatric Dentistry, Nikhil
Marwah.
3. Textbook of

70. THANK YOU