The document summarizes the development of the maxilla bone from the 4th week of gestation through postnatal growth. During the 4th week, maxillary processes develop from the mandibular arches on either side of the frontonasal process and stomodeum. The maxilla ossifies from mesenchyme in the maxillary processes. Postnatally, the maxilla grows through displacement by growth of the maxillary tuberosity, growth at sutural connections to the cranial base, and surface remodeling through bone deposition and resorption.

1. BY,
ANANTHESH H S
IV BDS

2. INTRODUCTION
 Maxilla is the 2nd largest bone of the face. It is a paired bone.
 Body of maxilla is pyramidal in shape, with its base directed medially at
the nasal surface, and the apex directed laterally at the zygomatic
process.
 It has four surfaces and encloses a large cavity; the maxillary sinus.
 Anterior or facial
 Posterior or infratemporal
 Superior or orbital
 Medial or nasal
• It has four processes,
 Zygomatic Process
 Frontal Process
 Alveolar Process
 Palatine Process

3. INTRODUCTION
Growth and development of an individual can be divided into
prenatal and postnatal periods with the former being more dynamic as
the growth in prenatal period being 5000 times more than what
happens in postnatal era.
Prenatal period can be divided into three periods:
1. Period of ovum
2. Period of embryo(1st to 8th week)
 Presomite
 Somite
 postsomite
3. Period of fetus.

4. FORMATION OF MAXILLARY AND MANDIBULAR PROCESS

5. DEVELOPMENT OF MAXILLA
 Around the fourth week of intrauterine life, a prominent bulge appears on
the ventral aspect of the embryo corresponding to the developing brain.
 Below the bulge a shallow depression which corresponds to the primitive
mouth appears called “ STOMODAEUM”.

6.  By around the 4th week of intra-uterine life, five branchial arches form in
the region of the future head & neck. Each of these arches gives rise to
muscles, connective tissue, vasculature, skeletal components & neural
components of the future face.
 The mesoderm proliferates and forms a projection that overlaps the
stomodeum. This projection is called as fronto-nasal process.
 The mandibular process gives off a bud from its dorsal surface called as
MAXILLARY PROCESS.

7.  The mandibular arch gives off a bud from its dorsal end called the
maxillary process which grows ventro-medio-cranial to the mandibular
process.
 At this stage the stomodeum is overlapped from above by the frontal
process, below by the mandibular process & on either side by the
maxillary process.

8.  Maxilla develops from a center of ossification in mesenchyme Of
maxillary process
 From this center bone formation spreads posteriorly below the orbit
towards developing zygoma and anteriorly towards incisor region.
 Downward extension also extends to form alveolar plate.
 Medial alveolar plate forms body of maxilla
 Lateral alveolar plate forms bony trough for tooth germ.

9. POSTNATAL GROWTH OF MAXILLA
The postnatal growth of maxilla occurs by,
Displacement
Growth at sutures
Surface remodelling
Displacement : -
It is divided into two types, 1. primary
2. secondary
 Primary type of displacement is seen in forward direction, this occurs
by growth of maxillary tuberosity in posterior direction.

10. DISPLACEMENT
 Primary type of displacement is seen in
forward direction, this occurs by growth
of maxillary tuberosity in posterior direction.
 As the cranial base grows it exerts pressure
on the nasomaxillary complex displacing it
in a downward and forward direction

11. GROWTH AT SUTURES
 The maxilla is connected to cranial base through many sutures. They
include
 fronto-nasal suture
 Fronto-maxillary suture
 Zygomatico- temporal suture
 Zygomatico-maxillary suture
 Pterygo-palatine suture

12. GROWTH AT SUTURES
 These sutures are oblique and more or less parallel to each other.
 As the growth occurs at these sutures, the maxilla is carried
downwards and forward.
 This leads to opening up of space at the sutural attachments.
 New bone is formed on either side of the suture. Thus the overall
size of the bones on either side increases. Hence a tension related
bone formation occurs at sutures

13. REMODELING
 The surface remodelling of the bone brings various changes. They
are,
 Increase in size.
 Change in shape.
 Change in functional relationship.
These changes are brought by bone deposition and resorption.

14. REMODELING
Following remodeling changes are seen in nasomaxillary coplex,
1. Resorption on lateral surface and deposition on external surface of
orbital rim—for lateral movements of eyeball.
2. Surface deposition on superior, lateral and Anterior surface of floor
of orbit.
3. Deposition along posterior aspect of maxillary tuberosity

15. REMODELING
4. Resorption along lateral wall of nose—increase
size of nasal cavity.
5. Resorption on anterior and deposition on posterior surface of
zygomatic bone.
6. Bone deposition along alveolar margins—to accommodate
teeth.

16. REFERENCES
 Orthodontics, Current Principles and Techniques – By Graber
 Orthodontics, The Art and Science – By S.I. Bhalajhi
 Textbook of Pediatric Dentistry – By Nikhil Marwah
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