growth and development of maxilla

GROWTH AND DEVELOPMENT
OF
MAXILLA
By- jasmine arneja preceptor-dr
payal sharma

CONTENTS
• Introduction
• Prenatal development of maxilla
• Prenatal development of palate
• Postnatal development of maxilla
• Postnatal development of palate
• Anomalies
• Refernces

• The face has 22 bones in an adult
• MAXILLAE are a pair of pneumatic bones and join
together to form the upper jaw
• They house the largest sinus in the body- the
maxillary sinus
• Each maxilla assists in forming the boundaries of
three cavities:
• the roof of the mouth
• the floor and lateral wall of the nasal antrum
• the wall of the orbit

EACH MAXILLA HAS 4 PROCESSES
FRONTAL
ZYGOMA
TIC
PALATINE
ALVEOLA
R

PRENATAL DEVELOPMENT OF MAXILLA

oThe prenatal life may arbitarily divided into 3 periods.
oThe period of ovum(fertilization to 2 weeks)
oThe period of embryo(2 weeks to 8th week)
oThe period of fetus(8th week to 9th month)
Inderbeer singh; human embryology, seventh edition

PRENATAL EMBRYOLOGY OF MAXILLA
• 4TH WEEK OF INTRAUTERINE LIFE

OSSIFICATION OF MAXILLA
• STARTS AROUND THE 8TH WEEK OF IUL
• INTRAMEMBRANOUS TYPE
The centre of ossification appears in the angle between the
division of a nerve i.e. where the anterosuperior dental
nerve is giving off from the inferior branch of infra orbital
nerve, above that part of the dental lamina from which
develop the enamel organ of the canine.
From this centre, the bone spreads :-
• Posteriorly: - Below the orbit toward the developing zygoma
• anteriorly: - Towards the future incisor region
• Superiorly: - To form the frontal process
Enlow’s; Essentials of Facial Growth, 4th Edition

DEVELOPMENT OF THE PALATE
• Palate is formed by the
• 2 palatal shelves of maxillary process
• Frononasal process
But fusion is prevented by the tongue
Around the 7th intra uterine week
Palatal shelves snap horizontally
The entire palate does not contact and fuse at the same
time, initial contact occurs in the region of the
secondary palate just posterior to the anterior or primary
palatine processes and continues both anteriorly and
posteriorly to this point.
The growth at mid palatal suture ceases between 1&2
years of age

• WHY?
• Alteration of the biochemical and the
physcal consistency of connective tissue
in palatal shelves
• Alteration in blood flow
• Muscular movements
• Withdrawl of the face from against the
heart prominence results in jaw opening
and tongue dropping
• Any anomaly in this phase results in non-fusion
of the palatal shelves and the
premaxilla resulting in a CLEFT PALATE

OSSIFICATION OF PREMAXILLA
• PREMAXILLA has two centers of ossification
• The palato-ficial center: Appear at the end of 6 WIU. It starts close to the
external surface of the nasal capsule, in front of the anterior superior dental
nerve and above the germ of the lateral deciduous incisor. From this center
bone formation spreads:
• Above the teeth germ of the incisors.
• Then downward behind them. To form the inner wall of their alveoli & palatal
part of the premaxilla.
• The prevomerine center ( paraseptal center ): It begins at about 8-9 WIU
along the outer alveolar wall. It is situated beneath the anterior part of the
vomer bone.

POSTNATAL DEVELOPMENT OF MAXILLA

POST NATAL DEVELOPMENT OF
MAXILLA
• Postnatal growth of maxilla is a multifactorial process
• According to Moss-
• Translation (displacement)
• Transposition (surface remodeling)

TRANSLATION / DISLOCATION
• Dislocation comprises of movement of the whole
bone as it simultaneously expands
• Displacement can be
• Primary
• Secondary
SCHOOLS OF THOUGHT
• Sutural theory
• Nasal septal theory
• Functional matrix

SUTURAL THEORY
• Sicher believed that craniofacial growth occurs at
sutures.
• Maxilla is attached to the cranium by
frontomaxillary, zygomaticomaxillary,
zygomaticotemporal and pterygopalatine suture,
which are more-or-less oblique and parallel to
each other
• Thus growth in these areas will push the maxilla
downward and forward
• But???
• Suture is a tension adapted tissue
• Suture doesn’t grow when transplanted
• Growth takes place in untreated cases of cleft
palate

NASAL SEPTUM THEORY
• James Scott
• He viewed cartilaginous sites throughout the skull
as primary centres of growth
• cartilage is a pressure-adapted tissue
• Pressure (of the growing brain) accommodating
growth of the nasal septum provides a source of
physical force that displaces the whole maxilla
anteriorly and inferiorly. This sets up field of
tension for the sutures, at which bone deposition
may now take place.
• But???
• Experiments are not decisive

FUNCTIONAL MATRIX THEORY
• Melvin moss
• Researches suggest that if there is no primordium for the eye, the orbit does
not develop
• Acc to him, the functional soft tissue matrix is the epigenic governing
determinant of skeletal growth process and all skeletal growth is secondary,
compensatory and mechanically obligatory to it.
• In achondroplastic dwarfs, the midface shows marked concavity and
retardation owing to deficient cartilage growth

TRANSPOSITION / REMODELLING
• If you see in the picture, The area previously
occupied by the ramus has now been
converted into mandibular body of the adult
• This is REMODELLING
• It is a sequence of differential deposition and
resorption that results in reshaping and resizing
of bone into its adult form
• The surface that faces the direction of
movement is depository and that away from it
is always resorptive

LACRIMAL SUTURE
• Lacrimal bone is a flake of bony island
with its entire perimeter surrounded by
sutures, separating it from many bones
• The lacrimal bone acts a key traffic
control, providing for slippage of multiple
bones along its perimeter
• In itself, the lacrimal bone undergoes
remodelling rotation

MAXILLARY TUBEROSITY AND KEY
RIDGE
• Maxillary arch grows in 3 directions
• Posteriorly deposition on posterior surface of
maxillary tuberosity
• Laterally- deposition on buccal surface of
tuberosity
• Downward- deposition along alveolar ridge
Endosteal surface is resorptive for growth of
maxillary sinus
Reversal occurs at key ridge, where most of the
external surface becomes resorptive

ZYGOMATIC ARCH
• Resorption at anterior surface and
deposition at the lateral and
posterior surfaces
• As a result the zygomatic arches
move posteriorly and bilaterally
outwards

ORBITAL GROWTH
To compensate for resorption in the endocranial side
To make the supraorbital rim more
prominent
V PRINCIPLE= Anterior – lateral- superior
relocation of orbit
To compensate for the downward growth of
nasomaxillary complex

POSTNATAL DEVELOPMENT OF
PALATE

POSTNATAL DEVELOPMENT OF
PALATE
• In early pre natal life the palate is relatively long but from the 4th
month it widens as a result of mid palatal suture growth and
appositional growth along the lateral alveolar margins.

• Growth of the mid palatal suture occurs between 1 and 2 years of
age.it is large in its posterior than in its anterior part, so that the
posterior part of the nasal cavity widens more than the anterior part.
• Lateral appositional growth continues until 7 years of age by this time
the palate achieves its maximum anterior width. Posterior appositional
growth continues after the lateral growth has ceased, so that the
palate becomes longer and wider during late childhood.

• The appositional growth of the alveolar processes contributes to
deepening as well as widening of the vault of the boney palate at the
same time adding to the height and breadth of maxillae.
• Ossification does not occur in the posterior part of the palate, giving rise to
the region of soft palate. Myogenic mesenchymal tissues of the I, II and IV
branchial arch migrates into this facial region supplying the musculature of
facial and palate.

DEVELOPMENTAL ANOMALIES
AFFECTING MAXILLA
• Cleft palate.
• Micrognathia.
• Macrognathia.
• Treacher collins syndrome (first arch
syndrome)
Cleidocranial dyplasia (This is an autosomal
dominant Oral features: - This includes high
arched palate, with or without clefts,
delayed eruption of teeth, malformed roots,
and supernumerary tooth)
Craniofacial dysostosis (premature closure of
the cranial and facial sutures- severe lack of
orbits, nasal, zygomatic and maxillary bone
components. Mandible will be normal and
they exhibit a class iii malocclusion with a ‘v’
shaped palate)

CLINICAL IMPLICATIONS
• Maxillary excessive growth can be reduced by maturation and
increased tonicity of perioral soft tissue. E.g. functional appliance.
• Functional imbalances due to extrinsic factors can be corrected if
excess factors are removed. E.g thumbsucking.

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.
• Orthodontic treatment irrespective of appliance depends to a great extent on
adaptive capacity of alveolar process, growth and remodelling.

REFERENCES
• Enlow’s; Essentials of Facial Growth, 4th Edition.
• Graber; Orthodontics, Current Principles and Practice.
• Inderbeer singh; human embryology, seventh edition

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