Growth and development of
the Nasomaxillary Complex

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Contents
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Introduction
Embryology & Prenatal growth
Natal growth
Post natal growth
Concepts of growt...
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In the closest union there is still some
separate existence of component
parts; in the most complete
separation there s...
Pharyngeal arches

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Early orofacial development
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The development of head depends on
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Prosencephalic centre
Rhombencephalic centre

Pr...
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Formation of the Human Face
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1st characterized by an invagination in the ectoderm
below the forebrain. As it deepens,it ...
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Face develops from 5 prominences
surrounding the stomodeum
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Frontonasal
Two maxillary processes
Two mandibular...
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Frontonasal prominence
4th week iu
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Develops from Cranial stream of neural crest
cells proliferate downwards to form FN ...
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5th week IU
 Face crowded between forebrain and heart
which begins to pulsate & affects development
of face because of im...
Fusion

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Fusion of MNP;LNP and MP –

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Fusion – MNP and MP provides –
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Continuity of upper jaw and lip.
Separati...
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7th week IU
 Shift of blood supply face from ICA to ECA
because of normal atrophy of stapedial artery.
 Potential for de...
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Development of Nose
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derives contribution from
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FN Prominence -Bridge.
MNP’s – Median Ridge and tip
LNP’s – Ala...
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5th week iu
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2 raised areas appear above future mouth.
centers of these raised areas become
depressions as tissues...
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It is separated from stomodeum by oronasal
membrane which disintegrate to form primary
chonae (primitive posterior nare...
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Within FNP –mesenchymal condensation
forms the precartilaginous nasal capsule
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Mesoethmoid-prologue to nasal sep...
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NASOLACRIMAL DUCT
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Between LNP and MP-rods of epithelial cells
sink into adjacent mesenchyme.Rods extend
from conjunctiv...
Upper Lip
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Forms in 3 steps
1-Contact between MP and MNP together
forming lamina nasal fin.

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2- fusion into a single ...
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Cranial Base
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The neurocranium can be divided into
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Calvaria-from desmocranium
Cranial base-from chondrocranium

www...
Chondrocranium
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4th week iu

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Occipital sclerotomal mesenchyme
concentrates around notochord and extends
cephalically ...
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The chondrification centers are

Parachordal cartilages-around notochord

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Sclerotomal cartilages-occipital bone par...
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Capsules around nasal and otic sense organs
ossify and fuse to the cartilages of cranial base
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nasal capsule- c...
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Chondrocranial ossification
 110 ossification centers in human
 45 bones in neonatal skull
 22 bones in adult
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Cen...
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CRANIAL BASE ANGULATION
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prechordal and chordal parts meet at an angle at the
hypophyseal fossa
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Lower angl...
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CRANIAL BASE FORAMEN
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I – determines perforations of cribriform plate

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II and opthalmic artery -orbitosphenoid cartil...
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cartilage between alisphenoid
and otic capsule –Foramen
Lacerum

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VII and VIII - otic capsule
ensures- internal acous...
FACIAL SKELETON
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Upper 1/3 of face –grows rapidly
Middle and lower 1/3 grow slowly and over a
prolonged period

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Facial bones develop intramembranously

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Interaction between neural crest
ectomesenchyme and overlying ectodermal
epi...
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Frontonasal prominence- 8th week – nasal and
lacrimal bone

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Maxillary Prominence – 8th week
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medial pteryg...
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Pre maxilla
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Originates in 7th week on the external surface
of nasal capsule. It extends upwards and
backwards where it ...
Maxilla
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Acc to Jacobson it develops from a condensation of
embryonic mesenchyme within the maxillary process
of t...
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Points of attachment

PM fissure – sphenoid and maxillary bone

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Pterygopalatine fossa – sphenoid and palatine

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Z...
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Growth of maxilla depends upon several functional
matrices that act on different areas and thus allowing
for its subdiv...
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The complexity of action of forces results in
different effects on different sutures
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TZ suture - A-P horizontal grow...
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Eyes
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Its growth provides an expanding force
separating neural and facial skeletons at FM
and FZ sutures therefore incre...
Eye balls
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Grow rapidly following neural pattern of
growth and contributing to rapid widening of
the face.

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half of p...
Nasal Cavity and Septum
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A septomaxillary ligament arises from nasal
septum and inserts into Anterior nasal spine. It
tr...
Palate
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Derived from
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two lateral max palatal shelves
primary palate of F-N prominence

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initially vertically orie...
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Factors influencing change of orientation
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Biochemical transformations in physical consistency of
connective tissue m...
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Fusion occurs initially - anteriorly in hard
palate, combination of degenerating epithelial
cells, and a surface coat a...
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The fusion initially produces a flat, unarched
roof.

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Junction of components -incisive papilla.
Line of fusion- mid ...
Cross-sectional
view of palate at
various ages

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Ossification - 8th week iu

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Anteriorly-primary ossification centre of
maxilla
Posteriorly- primary ossification cent...
Paranasal sinuses
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The 4 sinuses Maxillary ,Ethmoidal ,Sphenoidal
,Frontal- 3rd month iu as outpouchings of mucous
membr...
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AT BIRTH
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Maxilla at birth -contains deciduous teeth in
various stages of completion and buds of
permanent teeth.

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Al...
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Maxillary antrum - at birth has a slight
depression on the lateral wall of nasal cavity
opposite 2nd deciduous molar ge...
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Transverse palatine suture-according to
Woo the palatine process of maxilla and
horizontal parts of palatine bones over...
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Zygoma – anteriorly- joins maxilla through
the 1st deciduous molar.
Posteriorly through calcifying 1st permanent molar....
POSTNATAL GROWTH
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General Methods of Growth :
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Remodelling.
Displacement

Relocation
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Remodeling is a process of reshaping and
resizing a growing bone as it is relocated to
new levels.

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Reason- while pa...
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carried out by the osteogenic membranes and
other surrounding soft tissues

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bone itself contributes by feedback
info...
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Displacement – the whole bone is carried by a
mechanical force
Site -Articular contacts
1° displacement –th...
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2° displacement - movement of bone and soft
tissues not directly related to its enlargement.
Temporal lobe of cerebr...
primary movement-displacement or
remodelling?
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displacement is presently believed by many
researchers to be the primary ...
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Domino effect –
Growth changes are passed on from region to
region to produce a secondary spin off in areas
quite dista...
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Rotation –2 types
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Remodelling rotation
Displacement rotation.

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Nasomaxillary complex- displacement rotation
in ...
NASOMAXILLARY COMPLEX
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Remodeling - Posterosuperiorly
Displacement – Anteroinferiorly
Remodeling –

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Lacri...
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Lacrimal suture- is a bone surrounded by
Osteogenic sutural connective tissue capable
of responding to growth signals

...
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Maxillary Tuberosity :major
growth site

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Post surface -deposition –
lengthens arch
Buccal surface – deposition –
wid...
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Resorptive areas of nasomaxillary complex

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Vertical drift -As the maxilla and mandible
enlarge and develop the teeth drift horizontally
and vertically to keep pac...
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Palatal Remodelling -In a child the maxillary arch
and nasal floor lie very close to the orbital rim.
Remodelling resul...
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The palate widens according to Enlows V principle.

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Also growth at the mid palatal suture widens the
palate and the ...
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Nasal airway remodelingethmoidal concha
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deposition-lateral and inferior surface
resorption-superior and media...
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Displacement- Maxilla
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primary displacement-antero -inferior direction
grows and lengthens- posteriorly

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Maxillary sutures:
Primary displacement-multidirectional and thus
a slide of bones along interface occurs.
 Nasomaxillary...
Cheek bone and Zygomatic Arch
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malar protuberance- relocates posteriorly
Posterior side depository
anterior side resorpt...
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Orbital Growth
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Orbital roof -floor of anterior cranial fossa
remodels antero-inferiorly

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Lateral wall - resorption m...
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Growth of maxilla
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Earliest concept – maxillary growth pushes it
against pterygoid plates causing a resultant
force on i...
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Acc to Moss 3 types of bone growth
changes are to be observed in the maxilla.

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Due to 1)primary expansion of the or...
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Enlow and Bang- principle of “area
relocation”
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As growth continues, “specific local areas come to
occupy new actual ...
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STH-somatomedin

Direct effect-stimulates preosteoblasts
prechondroblasts

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Indirect effect-growth of septal cartila...
2

Septopremaxillary ligament traction effect

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Forward growth of septal cartilage-traction effect
on premaxilla-through...
3

Labionarinary muscle traction effect-

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Septal cartilage growth produces traction on
premaxilla through this muscle c...
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What is the primary growth center or
pacemaker for the maxilla?

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Moss and Greenberg-basic maxillary skeletal unit in...
NEUROCRANIUM
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The original pattern of skeleton-maintained.
Stationary biologic center-body of the
sphenoid

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The Basic...
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endocranial surface-resorptiveReason-sutures cant provide for multiple directions of
enlargement and remodeling

Fos...
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endocranial compartments-separated by bony
partitions
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depository in nature.
reason-fossae expand outward by res...
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Synchondroses- retention from primary
cartilages of chondrocranium after the
endochondral ossification cent...
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Recent research shows SE synchondrosis has
important ramifications in cleft palate
rehabilitation.

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synchondroses ar...
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sphenoid and occipital bones move apart by
primary displacement , and endochondral bone
is laid down by the endosteum w...
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Synchondrosis zones- reserve, cell
division, hypertrophic, and calcified
zones.

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Chondroblasts -aligned in distincti...
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Is displacement caused by growth
expansion, or the endochondral growth a
response to displacement caused by other
force...
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Cranial cartilages-autonomous growth units
that develop in conjunction with the brain, but
somehow independent of it.

...
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synchondrosis relates to the midventral axis
and not the entire cranial floor.

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Enlargement
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Midline-less
middle...
Effect on maxillary complex
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middle cranial fossa-causes
secondary displacement of
nasomaxillary complex

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maxillary c...
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Temporal and frontal
lobes expand (5-6 yrs).
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two fossae- pulled away
tension fields in the frontal,
temporal,...
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Acc to Weinmann and Sicher the sutures are
all oblique and parallel to each other. Thus
causing the maxilla to move dow...
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Hunter and Enlow-growth equivalents theory
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analyzed the effect cranial base growth on facial
growth

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emphasize bo...
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CONCEPTS OF GROWTH
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SUTURAL THEORY
CARTILAGINOUS THEORY
FUNCTIONAL MATRIX CONCEPT
MULTIPLE ASSURANCE
VAN LIMBO...
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Sicher sutural growth theory-

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growth at maxillary sutures-pushes bone apart
causing anteroinferior thrust on maxill...
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Scotts cartilaginous growth theory
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It is specifically adapted to pressure related
growth

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Supported by research b...
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Scott attributed an epiphyseal plate like effect
to the nasal septum.

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Recent research shows- nasal septum seems
mor...
Functional matrix concept
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any given bone grows in response to
functional relationships established by the sum
of all so...
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Brain rests on the chondrocranium and
theoretically exerts the same amount of force
downward as it would on desmocraniu...
Multiple Assurance – by Latham and Scott
1970
The process and mechanisms that function to
carry growth are multifactorial....
Van limborgh’s theory
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synchondroses and endochondral
ossification- controlled by intrinsic genetic
factors.

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intrins...
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sutural growth-controlled by cartilaginous
growth and growth of other structures.

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periosteal bone growth depends on...
Cybernetic theory

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THE DEVELOPMENTAL SEQUENCE
Balanced growth-form and proportion remain
constant
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The face –balanced+ imbalanced craniofac...
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Stage 1-

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remodeling of maxillary
tuberosity

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PTM moves posteriorly

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Maxillary arch length
increases same amou...


Stage2-

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displacement anteriorly

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Amount of fwd
displacement equals
amount of posterior
lengthening
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Stage3-

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temporal lobes and middle
cranial fossa –remodel

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The expansion projects it
beyond reference line

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Stage4-

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All parts anterior to reference
line-displaced forwards

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Reference line moves-same
extent as MCF

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Max...
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Stage5-

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floor ACF and forehead
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Deposition-ectocranium side
Resorption-endocranial side

Nasal bone disp...
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Stage6-

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vertical lengthening of
nasomaxillary region
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Primary displacement
Remodelingresorption-superior part o...
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Stage7-

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bone deposition –maxillary sutures

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equal to –maxillary displacement
inferiorly

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Palate and maxilla
...
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Stage 8

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zygoma and malar arearemodel posteriorly

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Stage 9-

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malar area-primary
displacement-anteriorly
and inferiorly

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Changes in growing face
Postnatally face increases primarily in length,
less in A-P depth and least in lateral width.

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...
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Face height –

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cartilages of nasal septum, upper facial
skeleton and condyle determine the direction
of growth of fa...
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Face depth –
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According to meredith

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the face depth increases at a slower rate
as age increases.

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Avg face dept...
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Sex differences in Face Growth –

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Girls complete A-P growth at puberty while
boys continue till maturity.

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Girls ...
NORMAL VARIATION AND
MALOCCLUSION
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Range of facial differences exists- brainlarge and variable
Broadly divided into


...
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Brachycepahlic

Wider and A-P shorter
basicranium

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Closed basicranial flexure

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Vertically and protrusively
short...
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Nasomaxillary complexretrusively placed


horizontal length short

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Composite result -relative retrusion

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

DolicocephalicLong and narrow basicranium

elongate and open and basicranial
flexure
A-P and vertical elongate facial
p...


nasomaxillary complex-

protrusive position; lowered
relative to the condyle
downward and backward
rotation of mandible...
Male versus female
Dolichocephalic- features parallel those of the
male face
Brachycephalic- features parallel those of th...
Child versus adult


Youthful face- brachycephalic

brain precocious relative to facial development.

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facial and phar...
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face is vertically short because
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Nasal part of the face is still diminutive

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Primary and secondary dentition not ...


Forward and downward
inclined middle cranial
fossa
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maxillary protrusive
mandibular retrusive effect

Maxilla...
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Upwards and
backward inclined
middle cranial fossa
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mandibular protrusion effect

Maxilla- placed backward
Ma...


Nasomaxillary complexvertically long
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Mandible- downward-backward
rotation

Class II molar relationship

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Nasomaxillary region vertically short


mandibular -protrusive effect



Mandible rotates forward and
upward

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Clas...


Maxillary retrusive and mandibular
protrusive effects-

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

Maxillary protrusive and mandibular
retrusive effects-

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

EFFECT OF NASOPHARYNGEAL
AIRWAY
Acc to Moss
functional spaces (oral, nasal, pharyngeal) are
not simply left over areas;...


Theories proposing a relationship between
mouth breathing and dentofacial form-

I. COMPRESSION THEORY
II. DISUSE ATROP...


Compression Theory-Tomes-1872.
Enlarged adenoids
Low tongue position
Unbalanced muscle equilibrium
Excessive force on m...


Disuse Atrophy Theory:
inactivity of nasal cavity causes an alteration
in maxillary arch



Nordlund (1918)- obstructi...


Moss stated that in Congenital Bilateral
Choanal Atresia - absence of Nasorespiratory
function.



Marked underdevelop...


Altered Air Pressure:


alteration of air pressure within nasal and
oral cavities during mouth breathing effects
dento...


Kantorowicz (1916) and James and Hastings
(1932)
In mouth breathing
negative pressure in sealed oral cavity lost
Palate...


Soft Tissue Stretch Hypothesis: Solow and
Kreiborg (1977)



Posturally induced stretching of soft tissue of
facial re...
In adenoid obstruction -increased cranio
cervical angulation.
 changes in Craniofacial morphology
corresponding to this c...
Studies showing association between
nasopharyngeal obstruction and dentofacial
form Experimental studies done on primates...


Critical review of literature- by 0’ Ryan et al-



suggests that simple cause and effect
relationship between nasores...
The Role of Ear in determining facial form


It’s role as space occupying organ ambiguous and minimal. The internal ear
r...
EVOLUTION OF HUMAN FACE


Brain Enlargement,
Basicranial Flexure



cerebrum expands around
smaller and lesser-enlarging...


orbital rotation-



Two separate axes

Vertical; horizontal



forehead- rotated into vertical plane
by brain, the ...
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

Orbital rotation reduces the interorbital
space and the structural base of the bony
nose.

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

Reduction in nasal protrusion
accompanied less equivalent reduction of
the upper jaw

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



Downward rotation of olfactory bulbs and
anterior cranial floor by the frontal lobes has
caused a downward rotation ...





Nasomaxillary
Configuration
Mammals-triangular.
Man-rectangular




rotation of occlusion in a
horizontal plane ...


Face also became markedly
widened of the increased
breadth of the brain.



The face now lies beneath
the frontal lobe...


downward – directed external nares aim the
inflow of air obliquely upward towards
sensory nerve endings in the olfactor...
Growth Field Boundaries




forward boundary of the brain and
nasomaxillary complex is shared
A line is drawn from the f...


Upper boundary



the nasal part of the face relates to the olfactory
bulbs and nerve.

The nasomaxillary complex dev...


Posteriorly 

Direction of growth- established visual
sense. The maxillary tuberosity is located
beneath the floor of ...


The posterior plane of midface extends from
junction between the anterior and middle
cranial fossa,downwards in a direc...


Inferior boundary- established when
growth is complete by inferior surface of the
brain and basicranium

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ANOMALIES


Unilateral, bilateral cleft lip



Oblique facial cleft and cleft
lip



Median cleft lip and nasal
defect
...


Ancephaly
Abs of neural crest cells –
neurocristopathy



Treacher Collins syndrome



Anhidrotic ectodermal
dysplasi...


Cleft palate-



Cleft lip and palate



Fetal alcohol syndrome
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CONCLUSION
Nasomaxillary complex growth is a
process requiring intimate morphogenic
interrelationships among all of it’s
c...
Thank you
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Leader in continuing dental education

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Growth and development of the nasomaxillary complex /certified fixed orthodontic courses by Indian dental academy

  1. 1. Growth and development of the Nasomaxillary Complex www.indiandentalacademy.com
  2. 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  3. 3. Contents            Introduction Embryology & Prenatal growth Natal growth Post natal growth Concepts of growth Developmental sequence Normal variation and malocclusion Nasopharyngeal airway Evolutionary changes Anomalies Conclusion www.indiandentalacademy.com
  4. 4.  In the closest union there is still some separate existence of component parts; in the most complete separation there still is a reminiscence of union. Samuel Butler www.indiandentalacademy.com
  5. 5. Pharyngeal arches www.indiandentalacademy.com
  6. 6. Early orofacial development  The development of head depends on    Prosencephalic centre Rhombencephalic centre Prosencephalic centre -migrates from the primitive streak  Induces    Visual and inner ear apparatus Upper 1/3 of face Caudal Rhombencephalic centre  Induces middle and lower 1/3 of face and middle and ext ears. www.indiandentalacademy.com
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  8. 8. Formation of the Human Face  1st characterized by an invagination in the ectoderm below the forebrain. As it deepens,it forms an outline of the oral cavity.  Prechordal Plate   demarcates the site of the stomodeum( 14th day) endodermal thickening contributes tooropharyngeal membrane. Ectoderm – forms mucosa of mouth.  Endoderm – forms mucosa of pharynx.  Mesoderm – does not intervene.  www.indiandentalacademy.com
  9. 9.  Face develops from 5 prominences surrounding the stomodeum     Frontonasal Two maxillary processes Two mandibular processes 1st Arch Derivatives All prominences and arches arise from neural crest cells-caudal stream www.indiandentalacademy.com
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  11. 11. Frontonasal prominence 4th week iu  Develops from Cranial stream of neural crest cells proliferate downwards to form FN process.  It surrounds the developing forebrain  Nasal placodes arises inferolaterally www.indiandentalacademy.com
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  15. 15. 5th week IU  Face crowded between forebrain and heart which begins to pulsate & affects development of face because of importance of blood supply.  The face grows downwards and forwards.  Face is about 11/2 mm wide. www.indiandentalacademy.com
  16. 16. Fusion  Fusion of MNP;LNP and MP –  Fusion – MNP and MP provides –    Continuity of upper jaw and lip. Separation of nasal pits from stomodeum. Fusion – MNP and MNP – at midline     Median tuberculum Philtrum Tip of nose Primary palate – gives rise to premaxilla. www.indiandentalacademy.com
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  19. 19. 7th week IU  Shift of blood supply face from ICA to ECA because of normal atrophy of stapedial artery.  Potential for defects upper lip and palate. www.indiandentalacademy.com
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  21. 21. Development of Nose  derives contribution from     FN Prominence -Bridge. MNP’s – Median Ridge and tip LNP’s – Alae Cartilage Nasal Capsule – Septum and nasal conchae. Superficial alar field – external alar cartilage. www.indiandentalacademy.com
  22. 22.  5th week iu   2 raised areas appear above future mouth. centers of these raised areas become depressions as tissues around them start growing Nasal pits become nostrils-fusion of MN, MP and LNP .  Distance between pits does not increase but pits increase in height and length. www.indiandentalacademy.com
  23. 23.  It is separated from stomodeum by oronasal membrane which disintegrate to form primary chonae (primitive posterior nares  Definite choane of adult –form by fusion of secondary palatal shelves. www.indiandentalacademy.com
  24. 24.  Within FNP –mesenchymal condensation forms the precartilaginous nasal capsule    Mesoethmoid-prologue to nasal septum Ectethmoid-ethmoid and nasal alar cartilage The primary nasal septum is broad – between primary choane but builds up in a rostrocaudal direction as the palatal shelves fuse. www.indiandentalacademy.com
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  27. 27. NASOLACRIMAL DUCT  Between LNP and MP-rods of epithelial cells sink into adjacent mesenchyme.Rods extend from conjunctival sac of developing eyelid to external nares.They later canalize to form nasolacrimal sacs and ducts and become completely patent after birth www.indiandentalacademy.com
  28. 28. Upper Lip  Forms in 3 steps 1-Contact between MP and MNP together forming lamina nasal fin.  2- fusion into a single sheet.  3-Degeneration of this sheet resulting in connective tissue penetration through it.  www.indiandentalacademy.com
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  31. 31. Cranial Base  The neurocranium can be divided into   Calvaria-from desmocranium Cranial base-from chondrocranium www.indiandentalacademy.com
  32. 32. Chondrocranium  4th week iu  Occipital sclerotomal mesenchyme concentrates around notochord and extends cephalically forming floor for the brain.  Conversion of the mesenchyme to cartilage constituents the beginning of chondrocranium www.indiandentalacademy.com
  33. 33.  The chondrification centers are Parachordal cartilages-around notochord  Sclerotomal cartilages-occipital bone parts  2 Hypophyseal cartilages-fuse to form basisphenoid cartilage  2 presphenoid cartilages- body of sphenoid   Orbitosphenoid and Alisphenoid- wings of sphenoid Mesoethmoid cartilage-fused presphenoid cartilages www.indiandentalacademy.com
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  35. 35.  Capsules around nasal and otic sense organs ossify and fuse to the cartilages of cranial base    nasal capsule- chondrifies in 2nd month to form nasal septum which ossifies into ethmoid and vomer otic capsules chondrify; fuse with parachordal cartilages to ossify as mastoid and petrous part of temporal bone All chondrification centres fuse to into a single irregularwww.indiandentalacademy.com plate porous basal
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  38. 38.  Chondrocranial ossification  110 ossification centers in human  45 bones in neonatal skull  22 bones in adult  Centres of ossification commence with the alisphenoids in 8 week IU  Unossified chondrocranial remanants persist at birth as     alae and septum – nose spheno-occipital and spheno- petrous junction apex – petrous bone between separate parts occipital bone www.indiandentalacademy.com
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  43. 43. CRANIAL BASE ANGULATION  prechordal and chordal parts meet at an angle at the hypophyseal fossa       Lower angle – from nasion to sella to basion 4 week - 150° (cartilage stage) 7-8 week - 130° 10 weeks – 115 - 120° (pre ossification Stage) 10-20 weeks–125–130° maintained postnatally. Flattening – is caused by rapid growth of brain during fetal period as chondrocranium retains its fetal flexure www.indiandentalacademy.com
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  46. 46. CRANIAL BASE FORAMEN  I – determines perforations of cribriform plate  II and opthalmic artery -orbitosphenoid cartilage fuses with basal plate-optic foramen.  III, IV, V, VI and ophthalmic veins-orbitosphenoid and alisphenoid – superior orbital fissure  Junction between alisphenoid and presphenoid cartilages are interrupted by V1 - Formen rotundum V2-Foramen ovale www.indiandentalacademy.com Middle meningeal artery-Formen spinosum
  47. 47.  cartilage between alisphenoid and otic capsule –Foramen Lacerum  VII and VIII - otic capsule ensures- internal acoustic meatus  IX,X,XI and IJV - otic capsule and parchordal cartilage- Jugular foramen  XII-occipital selerotomes – anterior condylar canal  Spinal cord – f. magnum www.indiandentalacademy.com
  48. 48. FACIAL SKELETON   Upper 1/3 of face –grows rapidly Middle and lower 1/3 grow slowly and over a prolonged period www.indiandentalacademy.com
  49. 49.  Facial bones develop intramembranously  Interaction between neural crest ectomesenchyme and overlying ectodermal epithelium is essential for differentiation of facial bones www.indiandentalacademy.com
  50. 50.  Frontonasal prominence- 8th week – nasal and lacrimal bone  Maxillary Prominence – 8th week      medial pterygoid plate vomer Greater wing of sphenoid Lateral pterygoid plate Palatine www.indiandentalacademy.com
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  53. 53. Pre maxilla  Originates in 7th week on the external surface of nasal capsule. It extends upwards and backwards where it joins the maxilla proper at 8th week www.indiandentalacademy.com
  54. 54. Maxilla    Acc to Jacobson it develops from a condensation of embryonic mesenchyme within the maxillary process of the mandibular arch 1° ossification centre-7th wk iu- at termination of infra orbital nerve just above the canine tooth dental lamina. 2° ossification centers – zygomatic orbitonasal nasopalatine www.indiandentalacademy.com intermaxillary
  55. 55.  Points of attachment PM fissure – sphenoid and maxillary bone  Pterygopalatine fossa – sphenoid and palatine  ZT suture – zygomatic bone and temporal  ZF suture -frontal and zygomatic bone  MF suture-frontal and maxillary  FN suture – frontal and nasal www.indiandentalacademy.com
  56. 56.  Growth of maxilla depends upon several functional matrices that act on different areas and thus allowing for its subdivision into skeletal units.  a) Basal body  b) Orbital unit  c) Nasal unit  d) Alveolar unit  e) Pneumatic unit www.indiandentalacademy.com
  57. 57.  The complexity of action of forces results in different effects on different sutures  TZ suture - A-P horizontal growth - brain and s-o synchondrosis.  F-M, F-Z, F-N, E-M,F-E suture - vertical growth eyeball and nasal septum expansion  N-M suture-A-P growth-nasal septum www.indiandentalacademy.com
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  59. 59. Eyes  Its growth provides an expanding force separating neural and facial skeletons at FM and FZ sutures therefore increasing the height.  They migrate medially due to expansion of frontal and temporal lobes of brain www.indiandentalacademy.com
  60. 60. Eye balls  Grow rapidly following neural pattern of growth and contributing to rapid widening of the face.  half of postnatal growth- 2 years adult dimensions- 7 years.  www.indiandentalacademy.com
  61. 61. Nasal Cavity and Septum  A septomaxillary ligament arises from nasal septum and inserts into Anterior nasal spine. It transmits septal growth ‘pull’ on the maxilla.  Facial growth is directed downwards and forwards by the septal cartilage www.indiandentalacademy.com
  62. 62. Palate  Derived from   two lateral max palatal shelves primary palate of F-N prominence  initially vertically oriented  8th week iu transformation from vertical to horizontal  considerable sex difference in timing. Earlier in male than female embryos. www.indiandentalacademy.com
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  64. 64.  Factors influencing change of orientation  Biochemical transformations in physical consistency of connective tissue matrices.  Variation in vasculature and blood flow  Sudden increase in tissue turgor.  Rapid mitotic activity  Intrinsic shelf force  Muscular movements  Withdrawl of face from heart prominence www.indiandentalacademy.com
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  66. 66.  Fusion occurs initially - anteriorly in hard palate, combination of degenerating epithelial cells, and a surface coat accumulation of glycoproteins and desmosomes facilitates epithelial adherence www.indiandentalacademy.com
  67. 67.  The fusion initially produces a flat, unarched roof.  Junction of components -incisive papilla. Line of fusion- mid Palatine suture.   This fusion seam is minimized in soft palate by invasion of extra territorial mesenchyme. www.indiandentalacademy.com
  68. 68. Cross-sectional view of palate at various ages www.indiandentalacademy.com
  69. 69.  Ossification - 8th week iu  Anteriorly-primary ossification centre of maxilla Posteriorly- primary ossification centre of palatine bones.   Mid palatal suture     10 1/2 weeks-fibrous layer in the midline. infancy Y shape in coronal section childhood - T shape adolescence - Interdigitated www.indiandentalacademy.com
  70. 70. Paranasal sinuses  The 4 sinuses Maxillary ,Ethmoidal ,Sphenoidal ,Frontal- 3rd month iu as outpouchings of mucous membrane of nasal meatus and spheno-ethmoidal recess.  primary pneumatisation-growth of mucous membrane sacs into the bone secondary pneumatisation-sinuses enlarge into bones  www.indiandentalacademy.com
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  73. 73. AT BIRTH  Maxilla at birth -contains deciduous teeth in various stages of completion and buds of permanent teeth.  Alveolar process is not developed and lies in same plane with palate.  Is in direct contact with bones of face and forms floor of orbit, roof of mouth and floor and lateral wall of nasal cavity www.indiandentalacademy.com
  74. 74.  Maxillary antrum - at birth has a slight depression on the lateral wall of nasal cavity opposite 2nd deciduous molar germ.  it’s growth displaces the erupting deciduous and permanent teeth www.indiandentalacademy.com
  75. 75.  Transverse palatine suture-according to Woo the palatine process of maxilla and horizontal parts of palatine bones overlap in an anterior direction.  Palate at birth - outer aspect has 2 parallel grooves.   external groove-dental groove inner -gingival groove. www.indiandentalacademy.com
  76. 76.  Zygoma – anteriorly- joins maxilla through the 1st deciduous molar. Posteriorly through calcifying 1st permanent molar.  Zygomatic arch grows by lateral addition and medial resorption. www.indiandentalacademy.com
  77. 77. POSTNATAL GROWTH  General Methods of Growth :    Remodelling. Displacement Relocation www.indiandentalacademy.com
  78. 78.  Remodeling is a process of reshaping and resizing a growing bone as it is relocated to new levels.  Reason- while parts of bone are moved; it maintains the form of the whole bone and causes its enlargement. www.indiandentalacademy.com
  79. 79.  carried out by the osteogenic membranes and other surrounding soft tissues  bone itself contributes by feedback information  Bionator-tries to alter this equilibrium  Fields of remodeling- resorptive and depository on the outside and inside of bone  Clinical significance-distalisation of molar www.indiandentalacademy.com
  80. 80.      Displacement – the whole bone is carried by a mechanical force Site -Articular contacts 1° displacement –the physical carry takes place in conjunction with the bones own enlargement vectors oriented–posteriorly and superiorly bone displaced – anteriorly and inferiorly www.indiandentalacademy.com
  81. 81.   2° displacement - movement of bone and soft tissues not directly related to its enlargement. Temporal lobe of cerebrum  Middle cranial fossa  Displace nasomaxillary complex downwards and forwards www.indiandentalacademy.com
  82. 82. primary movement-displacement or remodelling?  displacement is presently believed by many researchers to be the primary change with rate and direction of bone growth representing a secondary (transformative) response  It is also believed that both may be responding to common signals that separately but simultaneously activate both to operate in unison www.indiandentalacademy.com
  83. 83.  Domino effect – Growth changes are passed on from region to region to produce a secondary spin off in areas quite distant. Such effects are cumulative. www.indiandentalacademy.com
  84. 84.  Rotation –2 types   Remodelling rotation Displacement rotation.  Nasomaxillary complex- displacement rotation in either a clock or counter clock wise direction depending on growth activities of basicranium and sutural system.  Palate- remodeling rotation occurs in a counter direction. www.indiandentalacademy.com
  85. 85. NASOMAXILLARY COMPLEX   Remodeling - Posterosuperiorly Displacement – Anteroinferiorly Remodeling –       Lacrimal suture Max tuberosity Vertical drift of teeth Nasal airway Palatal remodelling. www.indiandentalacademy.com
  86. 86.  Lacrimal suture- is a bone surrounded by Osteogenic sutural connective tissue capable of responding to growth signals  allowing a slide of bones along their sutural surfaces;eg: it allows the maxilla to slide down its orbital contacts and thus displace inferiorly. www.indiandentalacademy.com
  87. 87.  Maxillary Tuberosity :major growth site  Post surface -deposition – lengthens arch Buccal surface – deposition – widens arch posteriorly Alveolar ridge and lateral side -deposition - downward growth Endosteal side -resorptive – sinus enlargement www.indiandentalacademy.com   
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  89. 89. Resorptive areas of nasomaxillary complex www.indiandentalacademy.com
  90. 90.  Vertical drift -As the maxilla and mandible enlarge and develop the teeth drift horizontally and vertically to keep pace in their anatomic positions.  the tooth and its alveolar socket drift together as a unit www.indiandentalacademy.com
  91. 91.  Palatal Remodelling -In a child the maxillary arch and nasal floor lie very close to the orbital rim. Remodelling results in downward relocation of the palate so that the arch lies considerably below the inferior orbital rim.  nasal region of the adult occupies an area where the bony max arch used to be located during childhood. www.indiandentalacademy.com
  92. 92.  The palate widens according to Enlows V principle.  Also growth at the mid palatal suture widens the palate and the alveolar arch In RPE - maxilla is1st displaced laterally; remodelling of the displaced segments follows  www.indiandentalacademy.com
  93. 93.   Nasal airway remodelingethmoidal concha    deposition-lateral and inferior surface resorption-superior and medial surface This moves them downwards and laterally www.indiandentalacademy.com
  94. 94.  Displacement- Maxilla   primary displacement-antero -inferior direction grows and lengthens- posteriorly www.indiandentalacademy.com
  95. 95. Maxillary sutures: Primary displacement-multidirectional and thus a slide of bones along interface occurs.  Nasomaxillary complex undergoes a frontal slide at junction with lacrimal, zygomatic, nasal and ethmoidal bones.  www.indiandentalacademy.com
  96. 96. Cheek bone and Zygomatic Arch  malar protuberance- relocates posteriorly Posterior side depository anterior side resorptive Zygoma -inferior edge-depository. Zygomatic arch -laterally and inferiorly Deposition- laterally downwards  resorption -opposite cortical sides  www.indiandentalacademy.com
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  98. 98. Orbital Growth  Orbital roof -floor of anterior cranial fossa remodels antero-inferiorly  Lateral wall - resorption medially deposition laterally  Floor of the orbit-remodels upwards deposition-superiorly resorption-inferiorly www.indiandentalacademy.com
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  101. 101. Growth of maxilla  Earliest concept – maxillary growth pushes it against pterygoid plates causing a resultant force on it anteriorly  discarded coz - bone’s osteogenic membrane is pressure sensitive and compression of capillary plexus causes necrosis. www.indiandentalacademy.com
  102. 102.  Acc to Moss 3 types of bone growth changes are to be observed in the maxilla.  Due to 1)primary expansion of the orofacial capsule.  2) alterations in maxillary functional matrices eg: orbital mass.  3) maintenance of the form of the bone www.indiandentalacademy.com
  103. 103.  Enlow and Bang- principle of “area relocation”  As growth continues, “specific local areas come to occupy new actual positions 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 proportion of each individual area in maxilla as a whole” www.indiandentalacademy.com
  104. 104.  STH-somatomedin Direct effect-stimulates preosteoblasts prechondroblasts  Indirect effect-growth of septal cartilage 1. Thrust effectgrowth of septal cartilage-thrust on premaxilla-stimulates growth of suture  Histologically-collagen fibers connecting cartilage and bone www.indiandentalacademy.com
  105. 105. 2 Septopremaxillary ligament traction effect  Forward growth of septal cartilage-traction effect on premaxilla-through this ligament  Studies(Petrovic;Stutzmann)-showed greater osteoblastic at this ligament junction with premaxilla  Histologically-ligament not able to provide traction  After resection-it has a local,induction like stimulating effect on subperiosteal growth www.indiandentalacademy.com
  106. 106. 3 Labionarinary muscle traction effect-  Septal cartilage growth produces traction on premaxilla through this muscle causing forward growth of upper jaw.  Cleft lip-absence of muscle attachment on nasal septum-bone malformations  Unilateral resection-unilateral decreased growth of operated side www.indiandentalacademy.com
  107. 107.  What is the primary growth center or pacemaker for the maxilla?  Moss and Greenberg-basic maxillary skeletal unit infraorbital neurovascular triad.basal boneprotection mechanism for the trigeminal nerve.This neurotrophic influence maintains the spatial constancy for the infraorbital canal with respect to the anterior cranial base and produces a similar constancy of the basal maxillary skeletal unit relative to the cranial base. www.indiandentalacademy.com
  108. 108. NEUROCRANIUM  The original pattern of skeleton-maintained. Stationary biologic center-body of the sphenoid  The Basicranium - “template” that establishes the growth fields within which nasomaxillary complex grows www.indiandentalacademy.com
  109. 109.   endocranial surface-resorptiveReason-sutures cant provide for multiple directions of enlargement and remodeling Fossa enlargement- direct remodeling   deposition-outside resorption -inside www.indiandentalacademy.com
  110. 110.  endocranial compartments-separated by bony partitions    depository in nature. reason-fossae expand outward by resorption, the partitions between them must enlarge inward, in proportion, by deposition. Remodeling of basicranium -stability for nerve and vessels . The foramen undergo drift to maintain proper position www.indiandentalacademy.com
  111. 111.       Synchondroses- retention from primary cartilages of chondrocranium after the endochondral ossification centers appear during fetal development Pressure adapted bone growth Sphenoethmoidal-5 to 25 years (max contribution- 6yrs) intersphenoidal- disappears at birth spheno-occipital intraoccipital - 3rd to 5th year www.indiandentalacademy.com
  112. 112.  Recent research shows SE synchondrosis has important ramifications in cleft palate rehabilitation.  synchondroses are primary centers of growth is supported by research of Sarnat, Burdi, Baume, Petrovic, and others.  Koski says these exist primarily to adjust the cranial base to needs of the brain and respiratory area. www.indiandentalacademy.com
  113. 113.  sphenoid and occipital bones move apart by primary displacement , and endochondral bone is laid down by the endosteum within each bone.  cortical (intramembranous) bone formed around the endochondral bone www.indiandentalacademy.com
  114. 114.  Synchondrosis zones- reserve, cell division, hypertrophic, and calcified zones.  Chondroblasts -aligned in distinctive columns along line of growth,with bipolar direction of linear growth www.indiandentalacademy.com
  115. 115.  Is displacement caused by growth expansion, or the endochondral growth a response to displacement caused by other forces?  Does the cartilage have an intrinsic genetic program that actually regulates growth? www.indiandentalacademy.com
  116. 116.  Cranial cartilages-autonomous growth units that develop in conjunction with the brain, but somehow independent of it.  Experimental studies show the independent proliferative capacity of synchondrosis is not greater than epiphyseal plates (more than condylar cartilage) suggesting extrinsic control factors are also required www.indiandentalacademy.com
  117. 117.  synchondrosis relates to the midventral axis and not the entire cranial floor.  Enlargement   Midline-less middle cranial fossae-more because it houses the various lobes which enlarge much more(laterally) www.indiandentalacademy.com
  118. 118. Effect on maxillary complex  middle cranial fossa-causes secondary displacement of nasomaxillary complex  maxillary complex posterior boundary positioned to coincide with the boundary between the anterior and middle cranial fossa www.indiandentalacademy.com
  119. 119.  Temporal and frontal lobes expand (5-6 yrs).     two fossae- pulled away tension fields in the frontal, temporal, sphenoidal, and ethmoidal sutures. Both fossae-enlarge nasomaxillary complex is carried along anteriorly www.indiandentalacademy.com
  120. 120.  Acc to Weinmann and Sicher the sutures are all oblique and parallel to each other. Thus causing the maxilla to move downward and forward (or the cranium upward and backward).  Sutures- increase the circumference bones involved www.indiandentalacademy.com
  121. 121.  Hunter and Enlow-growth equivalents theory  analyzed the effect cranial base growth on facial growth  emphasize both the timing of endochondral and intramembranous growth and the correlation of vectors and increments www.indiandentalacademy.com
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  123. 123. CONCEPTS OF GROWTH       SUTURAL THEORY CARTILAGINOUS THEORY FUNCTIONAL MATRIX CONCEPT MULTIPLE ASSURANCE VAN LIMBORGH’S THEORY CYBERNETIC THEORY www.indiandentalacademy.com
  124. 124.  Sicher sutural growth theory-  growth at maxillary sutures-pushes bone apart causing anteroinferior thrust on maxilla  discarded as - suture growth is tension adapted and is not adapted to pressure.  now believed-displacement of a bone produces tension which acts as a stimulus for sutural bone growth www.indiandentalacademy.com
  125. 125.  Scotts cartilaginous growth theory  It is specifically adapted to pressure related growth  Supported by research by Ohyama on rats In cleft palate cases,nasal septum grows normally   inhibition of sutural growth considered as of lack of cartilage growth –no cartilage growth, no sutural growth, no proliferation of connective www.indiandentalacademy.com tissue.
  126. 126.  Scott attributed an epiphyseal plate like effect to the nasal septum.  Recent research shows- nasal septum seems more important in anteroposterior than vertical growth.  Questioning Scott’s hypothesis –   periosteal growth is controlled by intrinsic factors why the periosteal membrane should be different in its action than sutural growth www.indiandentalacademy.com
  127. 127. Functional matrix concept  any given bone grows in response to functional relationships established by the sum of all soft tissues operating in association with that bone.  functional matrix is apparent in craniostenosis; discontinuation of sutural growth of calvaria, with the brain still growing, pressure is exerted on other areas, causing the eye to bulge, and producing other effects www.indiandentalacademy.com
  128. 128. www.indiandentalacademy.com
  129. 129.  Brain rests on the chondrocranium and theoretically exerts the same amount of force downward as it would on desmocranium.  This apparent high degree of independence of bone growth is further substantiated by the fact that it is very difficult to distort the chondrocranium in contrast to desmocranium.  Thus, there is apparent support for part of the Scott hypothesis while much research supports the Moss functional matrix explanation www.indiandentalacademy.com
  130. 130. Multiple Assurance – by Latham and Scott 1970 The process and mechanisms that function to carry growth are multifactorial. If 1 becomes inoperative other components have a capacity to ‘compensate’ ie: provide alternate means to achieve same developmental and functional and result. www.indiandentalacademy.com
  131. 131. Van limborgh’s theory  synchondroses and endochondral ossification- controlled by intrinsic genetic factors.  intrinsic factors controlling intramembranous bone growth are small in number and of a general nature.  cartilaginous skull parts- growth centers. www.indiandentalacademy.com
  132. 132.  sutural growth-controlled by cartilaginous growth and growth of other structures.  periosteal bone growth depends on the growth of adjacent structures.  intramembranous bone formation can also be influenced by local environmental factors. www.indiandentalacademy.com
  133. 133. Cybernetic theory www.indiandentalacademy.com
  134. 134. THE DEVELOPMENTAL SEQUENCE Balanced growth-form and proportion remain constant  The face –balanced+ imbalanced craniofacial parts  Enlow’s counterpart principle-growth of any given part relates specifically to other structural and geometric parts  Part and counterpart grow equal-balanced growth  Unequal-imbalanced growth www.indiandentalacademy.com 
  135. 135.  Stage 1-  remodeling of maxillary tuberosity  PTM moves posteriorly  Maxillary arch length increases same amount as PTM moves posteriorly www.indiandentalacademy.com
  136. 136.  Stage2-  displacement anteriorly  Amount of fwd displacement equals amount of posterior lengthening www.indiandentalacademy.com
  137. 137.  Stage3-  temporal lobes and middle cranial fossa –remodel  The expansion projects it beyond reference line www.indiandentalacademy.com
  138. 138.  Stage4-  All parts anterior to reference line-displaced forwards  Reference line moves-same extent as MCF  Maxillary tuberosity-constant www.indiandentalacademy.com
  139. 139.  Stage5-  floor ACF and forehead      Deposition-ectocranium side Resorption-endocranial side Nasal bone displaced anteriorly ACF-in balance with maxillary arch Nasal region-equivalent growth increments horizontally www.indiandentalacademy.com
  140. 140.  Stage6-  vertical lengthening of nasomaxillary region   Primary displacement Remodelingresorption-superior part of palate  Deposition-inferior side   Thus relocating it inferiorly ;thereby providing for vertical enlargement of above nasal www.indiandentalacademy.com region
  141. 141.  Stage7-  bone deposition –maxillary sutures  equal to –maxillary displacement inferiorly  Palate and maxilla  1-2- remodeling 2-3 primary displacement and sutural growth   Teeth  1-2 –vertical drift 2-3-displacement of www.indiandentalacademy.com maxilla
  142. 142.  Stage 8  zygoma and malar arearemodel posteriorly www.indiandentalacademy.com
  143. 143.  Stage 9-  malar area-primary displacement-anteriorly and inferiorly www.indiandentalacademy.com
  144. 144. Changes in growing face Postnatally face increases primarily in length, less in A-P depth and least in lateral width.  At birth Width - 57% of adult   Height- 40% Depth - 33% www.indiandentalacademy.com
  145. 145.  Face height –  cartilages of nasal septum, upper facial skeleton and condyle determine the direction of growth of face height.  From mid-fetal life to 5 years facial growth increases by 1/3.  Face shows a sustained and longer duration growth. www.indiandentalacademy.com
  146. 146.  Face depth –  According to meredith  the face depth increases at a slower rate as age increases.  Avg face depth is approx 3% larger in boys than girls. www.indiandentalacademy.com
  147. 147.  Sex differences in Face Growth –  Girls complete A-P growth at puberty while boys continue till maturity.  Girls face grows in height more than males till 15 years.  Males - growth - Depth > Height > Width Female - growth -Depth > Height –(upto 11 yrs) Height > Depth – (11-18yrs) www.indiandentalacademy.com 
  148. 148. NORMAL VARIATION AND MALOCCLUSION  Range of facial differences exists- brainlarge and variable Broadly divided into    Dolichocephalic Brachycephalic www.indiandentalacademy.com
  149. 149.  Brachycepahlic Wider and A-P shorter basicranium  Closed basicranial flexure  Vertically and protrusively shorter ;wider midface  the anterior cranial fossa sets up a wider but shorter and more shallow palate and maxilla. www.indiandentalacademy.com
  150. 150.  Nasomaxillary complexretrusively placed  horizontal length short  Composite result -relative retrusion www.indiandentalacademy.com
  151. 151.  DolicocephalicLong and narrow basicranium elongate and open and basicranial flexure A-P and vertical elongate facial pattern anterior cranial fossa sets up a www.indiandentalacademy.com narrower and deeper maxillary
  152. 152.  nasomaxillary complex- protrusive position; lowered relative to the condyle downward and backward rotation of mandible Occlusal plane rotated in a downward-incline www.indiandentalacademy.com
  153. 153. Male versus female Dolichocephalic- features parallel those of the male face Brachycephalic- features parallel those of the female face. Comparison- is relative whole body and lung size www.indiandentalacademy.com
  154. 154. Child versus adult  Youthful face- brachycephalic brain precocious relative to facial development.  facial and pharyngeal airway is yet small  Anterior cranial fossa is developmentally precocious-nasomaxillary complex- carried to a more protrusive position than the mandible www.indiandentalacademy.com
  155. 155.  face is vertically short because  Nasal part of the face is still diminutive  Primary and secondary dentition not fully established  Jaw bones not yet grown to the vertical extent. www.indiandentalacademy.com
  156. 156.  Forward and downward inclined middle cranial fossa     maxillary protrusive mandibular retrusive effect Maxilla- offset anteriorly Mandible- down and back Class II molar relationship www.indiandentalacademy.com
  157. 157.  Upwards and backward inclined middle cranial fossa     mandibular protrusion effect Maxilla- placed backward Mandible-rotates in a protrusive position. Class III molar relationship www.indiandentalacademy.com
  158. 158.  Nasomaxillary complexvertically long   Mandible- downward-backward rotation Class II molar relationship www.indiandentalacademy.com
  159. 159.  Nasomaxillary region vertically short  mandibular -protrusive effect  Mandible rotates forward and upward  Class III molar relationship www.indiandentalacademy.com
  160. 160.  Maxillary retrusive and mandibular protrusive effects- www.indiandentalacademy.com
  161. 161.  Maxillary protrusive and mandibular retrusive effects- www.indiandentalacademy.com
  162. 162.  EFFECT OF NASOPHARYNGEAL AIRWAY Acc to Moss functional spaces (oral, nasal, pharyngeal) are not simply left over areas; but volumetric growth of these spaces is 1° morphogenetic event in facial skull growth. The functional reality of respiratory and digestive system is patency of these space www.indiandentalacademy.com
  163. 163.  Theories proposing a relationship between mouth breathing and dentofacial form- I. COMPRESSION THEORY II. DISUSE ATROPHY THEORY. III.ALTERED AIR PRESSURE. IV.SOFT TISSUE STRETCH HYPOTHESIS www.indiandentalacademy.com
  164. 164.  Compression Theory-Tomes-1872. Enlarged adenoids Low tongue position Unbalanced muscle equilibrium Excessive force on maxillary arch buccal segments V-shaped dental arches. www.indiandentalacademy.com
  165. 165.  Disuse Atrophy Theory: inactivity of nasal cavity causes an alteration in maxillary arch  Nordlund (1918)- obstruction of nasal respiration due to adenoids nasal cavity undergo disuse atrophy relative elevation of palatal vault as alveolar process grows downward www.indiandentalacademy.com
  166. 166.  Moss stated that in Congenital Bilateral Choanal Atresia - absence of Nasorespiratory function.  Marked underdeveloprment of functional space occurs www.indiandentalacademy.com
  167. 167.  Altered Air Pressure:  alteration of air pressure within nasal and oral cavities during mouth breathing effects dentofacial form.  Bloch (1903) and Michel (1908) upward stream of oral airflow pressure on palate leads to higher palatal vault. www.indiandentalacademy.com
  168. 168.  Kantorowicz (1916) and James and Hastings (1932) In mouth breathing negative pressure in sealed oral cavity lost Palate not carried downward with growth of maxillary alveolar process www.indiandentalacademy.com
  169. 169.  Soft Tissue Stretch Hypothesis: Solow and Kreiborg (1977)  Posturally induced stretching of soft tissue of facial region might influence craniofacial morphological development  Hypothetically an extension of head, i.r.t cervical column - passive stretching of soft tissue enclosing face and neck.  www.indiandentalacademy.com Effect-backward and downward forces
  170. 170. In adenoid obstruction -increased cranio cervical angulation.  changes in Craniofacial morphology corresponding to this changed head posture.  www.indiandentalacademy.com
  171. 171. Studies showing association between nasopharyngeal obstruction and dentofacial form Experimental studies done on primates-  (1973) They blocked the Nasal passages of Rhesus monkeys and the monkeys gradually adapted from Nasal breathing to oral respiration HARVOLD, CHIERICI & VARGERVIK www.indiandentalacademy.com
  172. 172.  Critical review of literature- by 0’ Ryan et al-  suggests that simple cause and effect relationship between nasorespiratory function and dentofacial development does not exist, rather it is a complex interaction between hereditary and environmental influences www.indiandentalacademy.com
  173. 173. The Role of Ear in determining facial form  It’s role as space occupying organ ambiguous and minimal. The internal ear reaches its adult size in- 5-6 month iu.  It is the only organ that reaches full adult size by this age and thus minimises any influence on subsequent growth of facial skeleton. www.indiandentalacademy.com
  174. 174. EVOLUTION OF HUMAN FACE  Brain Enlargement, Basicranial Flexure  cerebrum expands around smaller and lesser-enlarging midventral segment-causes a bending of the whole underside of the brain. The flexure of the basicranium results www.indiandentalacademy.com
  175. 175.  orbital rotation-  Two separate axes Vertical; horizontal  forehead- rotated into vertical plane by brain, the superior orbital rims are carried with it.  temporal lobes- rotate orbits towards the midline www.indiandentalacademy.com
  176. 176. www.indiandentalacademy.com
  177. 177.  Orbital rotation reduces the interorbital space and the structural base of the bony nose. www.indiandentalacademy.com
  178. 178.  Reduction in nasal protrusion accompanied less equivalent reduction of the upper jaw www.indiandentalacademy.com
  179. 179.   Downward rotation of olfactory bulbs and anterior cranial floor by the frontal lobes has caused a downward rotation of the nasomaxillary complex. .The plane of the nasomaxillary region -perpendicular to the olfactory bulbs. www.indiandentalacademy.com
  180. 180.    Nasomaxillary Configuration Mammals-triangular. Man-rectangular   rotation of occlusion in a horizontal plane adapting to the vertical rotation of the midface. suborbital compartmentoccupied by maxillary sinus www.indiandentalacademy.com
  181. 181.  Face also became markedly widened of the increased breadth of the brain.  The face now lies beneath the frontal lobes of the brain. www.indiandentalacademy.com
  182. 182.  downward – directed external nares aim the inflow of air obliquely upward towards sensory nerve endings in the olfactory bulbs www.indiandentalacademy.com
  183. 183. Growth Field Boundaries   forward boundary of the brain and nasomaxillary complex is shared A line is drawn from the forward edge of the brain to prosthion.-MIDFACIAL PLANE www.indiandentalacademy.com
  184. 184.  Upper boundary  the nasal part of the face relates to the olfactory bulbs and nerve. The nasomaxillary complex develops in a growth field out to the edge of the brain perpendicular to the olfactory bulbs. www.indiandentalacademy.com
  185. 185.  Posteriorly  Direction of growth- established visual sense. The maxillary tuberosity is located beneath the floor of the orbit and aligned perpendicular to its axis. www.indiandentalacademy.com
  186. 186.  The posterior plane of midface extends from junction between the anterior and middle cranial fossa,downwards in a direction perpendicular to the neutral axis of the orbit  Posterior maxillary (PM) plane.  developmental interface between counterparts ahead and behind it www.indiandentalacademy.com
  187. 187.  Inferior boundary- established when growth is complete by inferior surface of the brain and basicranium www.indiandentalacademy.com
  188. 188. www.indiandentalacademy.com
  189. 189. ANOMALIES  Unilateral, bilateral cleft lip  Oblique facial cleft and cleft lip  Median cleft lip and nasal defect  Median mandibular cleft  www.indiandentalacademy.com Unilateral microstomia
  190. 190.  Ancephaly Abs of neural crest cells – neurocristopathy  Treacher Collins syndrome  Anhidrotic ectodermal dysplasia  Downs syndrome  www.indiandentalacademy.com
  191. 191.  Cleft palate-  Cleft lip and palate  Fetal alcohol syndrome www.indiandentalacademy.com
  192. 192. CONCLUSION Nasomaxillary complex growth is a process requiring intimate morphogenic interrelationships among all of it’s component growing, changing and functioning soft and hard tissue parts. No part is developmentally independent and self contained. www.indiandentalacademy.com
  193. 193. Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com

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