Post-natal Growth and development of face

POST-NATAL
GROWTH OF
FACE
Presenter: Dr. Prachee Rishi

Contents
• Introduction
• Post-natal growth
• Growth spurts
• A cornerstone of growth process
• Enlow’s “V” principle of growth
• Enlow’s counterpart principle
• Growth of craniofacial complex
 Growth of cranium
 Growth of upper face
 Growth of nasomaxillary complex
 Growth of mandible
• Growth patterns
• Growth rotations
• Facia forms and anatomic basis of
malocclusion
• Conclusion
• References

Introduction
• Growth may be defined as an increase in size
by natural development and is the consequence
of cellular proliferation and differentiation.
• "Growth" is a general term implying simply that
something changes in magnitude.
• “Development" is a maturational process
involving progressive differentiation at the
cellular and tissue levels.

• Morphogenesis is a biologic process having
an underlying control system at the cellular
and tissue levels.
• The clinician intervenes in the course of this
control process at some appropriate stage
and substitutes (augments overpowers, or
replaces) some activities of the control
mechanism with calculated clinical
regulation.

Post-Natal Growth
• Post-natal growth in humans is defined as the
growth occurring in first twenty years of life.
Post-natal
Growth
First 20 years
Infancy
First year of life
Childhood
1-14 years
Early
1-6 years
Middle
6-10 years
Late
10-14 years
Adolescence
14-20 years

Growth Spurts
• Growth of the body doesnot occur in a linear
fashion.
• Instead, periods of relative quiescence are
interrupted by periods of rapid skeletal growth,
which are called growth spurts.
• In humans, two major growth spurts are
documented:
1). Pre-pubertal growth spurt.
2). Pubertal growth spurt.

Growth spurts before and after birth
• Rapid rates of growth seen during infancy
are sometimes called as growth spurts of
infancy.
• Post-natal studies have shown increase in
1.6cm in 24 hours interspersed between
periods of very little measurable growth for
intervals as long as 2 months.

Pre-pubertal growth spurt
• Also known as childhood growth spurt.
• It is a small and inconsistent spurt seen in both
sexes at around 6-7 years of age.
The mid childhood spurt is associated with adrenarche,
an endocrine event related to increase in release of
androgenic hormones.
Transient spurt in height, accelerated bone maturation,
redistribution of body fat and appearance of pubic and
axillary hair.

Pubertal growth spurt
• Also known as adolescent spurt, pre-pubertal
acceleration, circumpubertal acceleration.
• It is the more predictable spurt and occurs
earlier in females than in males.
• This spurt is linked to increased secretion of
sex steroids (oestrogen in females and
testosterone in males) in conjuction with
growth hormones
• This spurt is itself divided into two stages:
Stage I and Stage II.

Stage I
• Period of accelerated growth.
• Females: 10.5-11 years.
• Males:13 years.
• It lasts for about 2-3 years in both sexes (11-13
years in females and 13-15 years in males).
• The peak height velocity (PHV) during this stage
may reach 9.8 cm per year for males (at around
14 years of age) and in females around 8.1 cm
per year (at 12-13 years of age).

Stage II
• Phase of deceleration of growth.
• Lasts for about 3 years (13-16 years in females and
15-18 years in males).
• Both sexes gain about 6 cm in height, most of which
is contributed by lower limbs.
• Following conclusion in the spurt rapid reduction in
height velocity occurs.
• Females attain 98% of their final height by about 16
years and males attain the same by around 18 years.
• In females, menarche generally occurs one year
after PHV and little skeletal growth takes place
after onset of menarche.

Mini growth spurts
• Everyday, periods of exaggerated growth may
be interspersed with times of little or no
activity, known as mini growth spurts.
• Growth cycles have been found on a weekly as
well as daily basis corresponding to rhythmic
changes in the levels of circulating hormones.
Daily basis
• A person may be slightly taller in
morning and by evening, due to
effect of gravity causing compression
of intervertebral disc he or she may
measure slightly shorter.
Weekly basis
• Small but rapid burst of growth may
be seen interspersed with time of
little activity.
• Dual effector hypothesis.

A Cornerstone of growth
process
• A grasp of how facial growth operates begins with
distinction between the two basic kinds of growth
movement.
Deposition of bone on any surface pointed
toward the direction of enlargement of a
given area; resorption usually occurs on
the opposite side of that particular bony
cortex (or cancellous trabecula).
Remodelling
Separate movement of the whole bone by
some physical force that carries it, in
toto, away from its contacts with other
bones, which are also growing and
increasing in overall size at the same time.
Displacement

Click icon to add picture
Two-phase
remodeling-
displacement
process takes place
virtually
simultaneously.

As the bone enlarges
in a given direction
within the joint, it is
simultaneously
displaced in the
opposite direction

Remodelling
The functions of remodeling are to:
1. Progressively create the changing size of each whole bone .
2. Sequentially relocate each of the component regions of the
whole bone to allow for overall enlargement.
3. Progressively shape the bone to accommodate its various
functions.
4. Provide progressive fine-tune fitting of all the separate
bones to each other and to their contiguous, growing,
functioning soft tissues.
5. Carry out continuous structural adjustments to adapt to
the intrinsic and extrinsic changes in conditions.

• The surface that faces toward the direction of
movement is depository (+).
• The opposite surface, facing away from the
growth direction, is resorptive (- ).
• If the rates of deposition and resorption are
equal, the thickness of the cortex remains
constant.
• If deposition exceeds resorption, overall size
and cortical thickness gradually increase.
• The change in position of a bony structure owing
to remodelling of that structure is called drift.

Black arrows are
surface
resorptive,
and white arrows
are depository.

The pattern of growth fields
results in a rotation of the
skeletal part.
The cortex on the right was
formed by the periosteum and
the cortex on the left by the
endosteum as both sides shifted
(drifted) in unison to the right.

Why do
bones
remodel as
they grow?
The key factor is the
process of
relocation.
The mandible does not grow by a
simple symmetrical enlargement
rather the condyle and ramus
elongate in a posterior and
superior direction, whilst the
body of the mandible lengthens

Displacement
• The displacement movement is believed to be the
pacemaking (primary) change, with the rate and direction
of bone growth representing a trans formative
(secondary) response.
• As a bone enlarges, it is simultaneously carried away from
other bones in direct articulation with it.
• This creates the "space" within which bony enlargement
takes place at the interface between bone-to-bone joint
contacts. The process is termed displacement (also called
'translation").
• It is a physical movement of a whole bone and occurs
while the bone simultaneously remodels by resorption and
deposition (to an equivalent extent).

Primary
displacement
In primary displacement, the process of physical
carry takes place in conjunction with a bone's own
enlargement
Growth at condyle leads
to primary displacement
of mandible in
anteroinferior direction
Two principal remodeling vectors in
the maxilla, posterior and superior,
leads to displacement of maxilla in
opposite anterior and inferior
directions.

Secondary
displacement
Click icon to add picture
In secondary
displacement, the
movement of bone and
its soft tissues is not
directly related to its
own enlargement
The anterior direction of
growth by the middle cranial
fossae and the temporal lobes
of the cerebrum secondarily
displaces the entire
nasomaxillary complex
anteriorly and inferiorly

Enlow’s V principle of
growth
According to this principle,
bone deposition occurs on
the inner side of the V while
resorption takes place on the
outside surface, which leads
to widening of the V
configuration; at the same
time, the structure translates
from its original position and
moves towards the wide end
of the V.

Enlow’s counterpart
principle
Growth of any
given facial or
cranial part relates
specially to other
structural and
geometric
counterparts in the
face or cranium.
Counter
part
Regional
part
Balanced
growth
Regional part Counter part
Palate Anterior cranial
fossa
Middle cranial
fossa
Ramus of the
mandible
Maxillary arch Mandibular arch
Maxillary
tuberosity
Lingual
tuberosity
Bony maxilla Corpus of
mandible

Post-natal Growth and development of face

Growth of
Craniofacial complex
Anatomically, the craniofacial skeleton can be
divided into the viscerocranium and the
neurocranium.
• Represented by skull vault and
cranial base, which surrounds the
brain, eyes and middle or inner ear.
Neurocranium
• Includes the bones of the face and
jaws.
Viscerocranium

Bones of craniofacial complex: their
ossification and derivation

Growth of cranium
Cranial vault
• At birth, the sutures of the cranial bones do not
inter-digitate, as they are separated from each
other by areas of interposed connective tissue.
These areas are called fontanelles.
• There are six fontanelles at the time of birth: two
unpaired and two paired.
• The unpaired fontanelles include the anterior and
the posterior fontanelles.
• The anterior fontanelle is large and square in shape,
while the posterior fontanelle is smaller and
triangular in shape.

• The paired fontanelles include the sphenoidal and
mastoid fontanelles, both of which lie on the lateral
sides of the skull.
• All the fontanelles are occluded with fibrous
connective tissue except the mastoid fontanelle which
is occluded by cartilage (also known as synchondrosis).
• Fontanelles allow deformation of the head and thus
help the large head of the foetus pass through the
birth canal.
• They also help in accommodating the rapidly enlarging
brain in early childhood.
• They close at different times after birth.

Fontanelle Type Adjacent bone
anlagen
Time of fusion
(after birth)
Anterior Unpaired Both frontal and
parietal
36th
month
Posterior Unpaired Both parietal and
occipital
3rd
month
Sphenoidal Paired Frontal, parietal and
sphenoid
6th
month
Mastoid Paired Sphenoid, temporal
and occipital
18th
month

• With the fusion of the fontanelles, the remaining
growth and remodelling of the cranial vault occur
mainly at the sutures.
• Increase in the size of the brain creates tension at the
sutures, which leads to new bone deposition in the area.
• Remodelling of the outer and inner surfaces of cranial
bones also occurs to allow contour changes with growth.
• The cranial cavity achieves 87% of its adult size by the
age of 2 years, 90% by 5 years and 98% by 15 years of
age.
• Between 15 years and adulthood, additional growth
changes occur secondary to pneumatisation of the
frontal sinuses and thickening of the anterior part of
the frontal bone.

Bone growth in the
cranial vault.
As growth of the brain
passively expands the
flat bones, compensatory
bone growth at the
sutures maintains
patency (A). Whilst
external and internal
surface remodelling
reduces the curvature
and adjusts their
relationship as they
are displaced radially (B).

Cranial base
• Cranial base is the most stable structure among
the facial structures, and its growth is affected
least by functional matrices.
• It provides the points of articulation between
the skull and both the vertebral column and
mandible.
• It supports the brain and provides a platform
from which the face grows.
• It also tethers the pharynx, a structure common
to both the face and neck.

• Cranial base synchondroses are important
growth centres of the craniofacial skeleton and
the last sites in the cranium to terminate
growth.
• They mediate pressure-adapted primary
endochondral growth and act directly to
increase the anteroposterior dimension of the
skull base.
• Once growth in the synchondroses has ceased,
the cartilage is replaced by bone to form a
synostosis.

• There are five major synchondroses in the cranial
base: intraethmoidal, intra-sphenoidal, intra-
occipital, sphenooccipital and sphenoethmoidal.
• The intra-ethmoidal and intra-sphenoidal
synchondroses close before birth.
• The intra-occipital synchondrosis closes at 5 years,
while the sphenoethmoidal synchondrosis closes
around 6 years of age.
• The spheno-occipital synchondrosis persists for
longer.
• Direct histological examination of autopsy material
suggests that in females it closes around 13–15 years
of age, whilst in males it remains patent until 15–17
years.

• The spheno-ethmoidal and spheno-occipital
synchondroses make the most significant
contributions to postnatal growth of the cranial
base.
• Growth at the sphenooccipital synchondrosis
causes elongation of the middle portion of the
cranial base as a result of primary displacement
• While growth at the posterior part leads to
flexion in the cranial base since the posterior
part of sphenooccipital synchondrosis has a
greater amount of bone formation in its inferior
part than its superior part.

Surface
remodelling
within the
cranial base.

The cranial base
expands in a
three-dimensional
format due to
angulation of the
sutures and
synchondrosis at
the cranial base.

Resoption and
deposition
patterns

Any degree of cranial base flexion between articulating part
will directly affect the skeletal pattern of the jaws. As the
cranial base angle becomes more obtuse, the mandible
becomes more retrognathic relative to the maxilla (left
panel). Conversely, a more acute angle makes the mandible
more prognathic (right panel).

• As the cranial base elongates and expands via
cartilaginous growth and surface remodelling,
compensatory intermembranous growth at the
sutures maintains patency of the bony
articulations within this region.
• Sutures with a coronal orientation
(frontosphenoid, sphenotemporal,
occipitomastoid) contribute to anteroposterior
growth, whilst the sagittal-orientated sutures
(frontoethmoid, sphenotemporal,
occipitomastoid) are responsible for some
growth in width.

Craniosynostosis
(Premature closure of
sutures)

Growth of face
• The face or viscerocranium is
one of the more complex
regions of the skull.
• It incorporates many different
anatomical and functional
spaces and is composed of
almost a dozen individual
bones, many of which are
paired and most of which
develop intramembranously.
• The face as a whole grows
downwards and forwards in
relation to the cranial base.
FACE
Upper face
Nasomaxillary
complex
Mandible

Growth of upper face
• Growth of this region is dominated by the
frontal bone and orbits.
• The frontal bone contributes to the base of the
anterior cranial fossa, roof of the orbits and
the surface of the forehead.
• As a membrane bone, it grows via sutural and
(predominantly) surface remodelling and is
therefore influenced by growth of the brain,
eyeballs within the orbits and midface.

• The orbits have contributions
from the frontal, zygomatic,
maxilla, lacrimal, ethmoid,
palatine and sphenoid bones.
• Early growth of this region
occurs through relocation and
displacement secondary to
growth of the eyeball itself.
• Later growth produces
inferior and lateral expansion
secondary to accompanying
changes in the anterior
cranial fossa and maxilla.

Growth of Nasomaxillary
complex
• The nasomaxillary complex forms the middle part
of the facial skeleton and is dominated by the
orbits, nasal cavity, upper jaw and zygomatic
processes.
• A number of bones make contributions to this
region, including the frontal, sphenoid, zygomatic,
lacrimal, nasal, maxillary, palatine, ethmoid and
vomer.
• Growth of the nasomaxillary complex occurs by
primary growth, secondary displacement and
surface remodelling.

Composite
growth and
direction of
displacement of
maxilla.

Cranial base contribution
Growth of the cranial base has
a major secondary displacement
effect on the anterior cranial
fossa and nasomaxillary
complex causing their forward
displacement.
As the middle cranial fossa
grows, it displaces the maxilla in
an anterior and inferior
direction.

Growth at sutures
• The maxillary complex is attached to the cranium by
zygomaticomaxillary sutures, frontomaxillary sutures,
zygomaticotemporal sutures and pterygopalatine
sutures.
• Growth at these sutures leads to anterior and
vertical descent of the maxilla.
• Growth at the median palatine suture enhances
transverse dimensions of the maxilla.
• Following the cessation of cranial base development at
6–7 years, growth at the sutures and nasal septal
cartilage are the primary contributors to further
growth of the maxilla.

Role of nasal septum
• Growth of the cartilaginous part of the vomer and
the perpendicular plate of the ethmoid contribute
to downward and forward growth of the maxilla.
• This growth also creates space in the posterior
region in the area of a tuberosity for the eruption
of the permanent molars.
• Nasal cartilage has innate growth potential and
serves as a primary growth centre, in contrast to
the mandibular condyle.

Removal of nasal
septum
Mid-face deficiency

Surface remodelling and growth at
alveolar process
Deposition at the
posterior end of the
maxilla (tuberosity)
causes an increase in
anteroposterior
dimensions (length),
while surface resorption
at the facial surface gives
the maxilla its
characteristic contour as
a result of its functional
needs.

Deposition on the
palatal surface and
resorption at the
nasal surface of the
palatal process lead
to downward drift
of the palate, which
increases the size
of the nasal cavity.
Palatal growth

At the same time, growth of the alveolar process
contributes to enhancing the depth of the palate.
Surface remodelling also contributes to increase in the
width of the maxilla and expansion of the nasal airway.
Deposition on the buccal aspect of the alveolar process
along with growth across the mid-palatine suture
contribute to increase in width.

Growth at
anterior surface
of maxilla

Growth of sinuses
• The sinuses are air-filled cavities within the
craniofacial skeleton.
• They have important biological functions such as
pneumatisation of the skeleton and humidification
of inspired air.
• The sinuses grow by resorption of adjacent bony
surfaces.
• While most sinuses achieve near adult size by 12
years, the frontal sinus continues to enlarge till 20
years, which may contribute to the forward shift
of the nasion.

The Lacrimal Suture: A
Key Growth Mediator
• The lacrimal bone and the sutural
system surrounding it, according to
Enlow, are the key for midfacial
growth and development.
• It is the lacrimal sutural connective
tissue which allows for slippage of
the bones at the interfaces.
• The slippage is probably responsible
for net downward and forward
growth of nasomaxillary complex.
• One bone slides along the suture as
new bone tissue is laid down at
suture margins.

Myofibroblasts Contractile fibre
Tension in the
suture
Bone displacement
Pull one bone
across the suture
towards another
Downward and
forward growth of
nasomaxillary
complex

The Cheekbone and Zygomatic Arch
The growth changes
of the malar complex
are similar to those
of the maxilla itself.
This is true for the
remodeling process
as well as the
displacement
process

The Maxillary Tuberosity and the Key
Ridge
• It lengthens posteriorly by
deposition on the posterior-
facing maxillary tuberosity.
• It grows laterally by deposits
on the buccal surface (this
widens the posterior part of
the arch).
• It grows downward by
deposition of bone along the
alveolar ridges.
The bony
maxillary
arch is
moving in
three
directions
by bone
deposition
on the
external
surface :

• A major change in surface contour occurs
along the vertical crest just below the
malar protuberance (small arrow). This
crest is called the "key ridge.“
• A reversal occurs here.
• Anterior to it most of the external
surface of the maxillary arch (the
protruding "muzzle“ in front of the
cheekbone) is resorptive.
• The resorptive nature of this surface
provides an inferior direction of arch
remodeling in conjunction with the
downward growth of the palate.
• This is in contrast to area a , which grows
downward by periosteal disposition.

The Vertical Drift of Teeth: An
Important Clinical Consideration
• As the maxilla and mandible enlarge
and develop, the dentition drifts both
vertically and horizontally to keep
pace in respective anatomic positions.
• The process of drift moves the whole
tooth and its socket; that is, the
tooth does not drift vertically out of
its alveolar housing as it does in
eruption (or as implicit in the term
"extrusion").
• Rather, in vertical drift, the socket
and its resident tooth drift together
as a unit.

Summary of Maxillary remodelling

Growth of Mandible
Mandibular growth occurs
by a combination of:
Surface remodelling
Growth at the condylar
cartilage

Condylar growth
• The mandibular condyle is an important site for mandibular
growth.
• It is a secondary fibrocartilage and is covered with poorly
vascularised fibrous connective tissue.
• Growth of the condyle occurs by proliferation of
fibrocartilage, which subsequently gets ossified into bone.
• This causes an increase in the overall length of the
mandible, while displacing the chin downwards and forwards.
• It is important to note that condylar cartilage is a site of
growth but not a growth centre as it has little innate
growth potential.

Growth at the condyle
leads to anterior and
inferior displacement of
the mandible due to
increase in the ramus
and body length.

Ramus to Corpus remodelling
• Growth of the ramus occurs in all three
dimensions: superiorly, posteriorly and
transversely.
• The growth vector of the mandible is posterior
and superior, and ramus remodelling occurs in a
similar direction.
• Superior growth leads to increase in ramus height,
which is primarily due to growth at the condyle.
• Posterior growth of the ramus occurs by cortical
drift and surface remodelling at the junction of
the ramus and the body of the mandible (corpus).

• The ramus grows posteriorly by selective
deposition at the posterior border and resorption
at the anterior border.
• This also lengthens the corpus and provides space
for the developing molars.
• The pattern is continued up to the beginning of
the coronoid notch, where the anterior surface
becomes depository in response to functional
demands imposed by the temporalis muscle.
• The lingual tuberosity forms the boundary
between the ramus and the corpus of the
mandible.

• Transversely, the ramus widens as it grows
posteriorly.
• This is caused both by growth of the corpus, V-
shape configuration of which pushes the ramus
outwards as it grows backwards, as well as by
selective deposition and resorption patterns on the
posterior and anterior surfaces of the ramus.
• Below the inferior alveolar canal and along the
posterior border of the ramus, the medial surface
is resorptive, while the lateral surface is
depository.
• Above the alveolar canal, along with the anterior
border up to the coronoid notch, the medial surface
is depository, while the lateral surface is
resorptive.

Coronoid process
• Remodelling of the
coronoid process also
follows the V principle, just
like the ramus.
• There is resorption on the
buccal side and deposition
on the lingual side of the
coronoid process under the
action of the temporalis
muscle.

Body of the mandible
• Increase in the length of
the mandible occurs by
remodelling at the anterior
border of the ramus, while
increase in height occurs
by development of the
alveolar process in
response to tooth eruption.
• When seen from the side,
the entire inferior border
is depository, while
resorption is seen in the
antegonial notch area.

• Laterally, on the buccal
surface, the mandibular
foramen drifts backwards and
upwards as deposition takes
place on the anterior rim and
resorption takes place on the
posterior rim of the foramen.
• When the body of the mandible
is seen in cross-section,
remodelling patterns widen the
base of the mandible laterally.
• On the medial side, below the
inferior alveolar canal,
resorption occurs, while on the
buccal side, the process of
deposition continues.

Alveolar process
• The alveolar process develops
as the teeth erupt in
response to functional
demands.
• Where there is partial
anodontia, growth of the
alveolar process is hampered.

Growth at the chin
• Growth at the chin occurs primarily by surface
remodelling, which usually has an inconsistent pattern
depending significantly on the growth pattern of the
individual.
• Chin prominences are due to deposition of bone on the
anteroinferior surface and resorption anterosuperiorly
at the root apices of the mandibular incisor and due to
late mandibular rotation in a forward direction.
• The entire remodelling process and growth rotation along
with development of the alveolar process give the
anterior surface of the chin an S-shaped contour.

Summary of Mandibular remodelling

Pathological causes of abnormal mandibular growth

Comparison
between adult and
new-born infant
skulls.
o The infant face is wide because
of the large cranium and orbits,
but also short because of a lack
of development within the
nasal complex and jaws.
o The floor of the nasal cavity is
sandwiched between the orbits
and there is little vertical
development of the maxilla
and mandible in the neonate.
o The adult skull is characterized
by a nasal cavity situated
below the orbits and significant
vertical elongation of the jaws.

Sequence of growth in
different planes
Growth in width-
transverse plane
Growth in length -
anterio-posterior plane
Growth in height-
vertical plane
TRANSVERSE PLANE
• Growth completed before
adolescent growth spurt
• Minimally affected by
adolescent growth changes
ANTERO-
POSTERIOR
PLANE
Jaws to continue
throughout puberty
VERTICAL PLANE
Growth occurs upto 18-19
years
Width
Depth
Height

Growth patterns
• A tendency for the mandible to rotate
upward and forward.
• The lower anterior facial height is
relatively short with a tendency for
deep bite.
• Squarish face, a low mandibular plane
angle, well-developed jaw elevators,
increased biting force, and broad dental
arches.
• Jaw bones are dense and hence
orthodontic tooth movement through
this bone may sometimes become
difficult, especially in adult cases.
Horizont
al growth
pattern

• The growing mandible rotate
downwards and backwards.
• Anterior facial height is increased
especially the lower anterior face
height.
• The muscular forces of the jaw
elevators such as the temporalis
and masseter are weak compared
with horizontal growers, and
there is a tendency for anterior
open bite.
• The dental arches are narrower
and jaw bone density is relatively
less.
Vertical
growth
pattern

Growth rotations
Forward rotation:
• Counter-clockwise
rotation
• Three types according
to site of centre of
rotation: type I, type
II and type III.

Type I
• COR: TMJ
• With mandible
rotation,the condyles
and the lower incisors
move superiorly.
• Reduced depth of the
antegonial notch, a
brachycephalic head
type, anterior deep bite
and strong muscular
pattern of the face.
Type II
• COR: incisal edges of
lower anterior teeth.
• Posterior face height
increases
disproportionately in
relation to anterior face
height
• Excessive loading of
masticatory forces leads
to wearing away of the
anterior teeth, thus
resulting in loss of
anterior face height.
Type III
• COR: between condyle
and incisor edge.
• Subjects with large
anterior overjet.
• COR displaced
backwards to the level of
the premolars.
• Such cases present with
basal anterior deep bite.

Downward and clockwise
rotation of mandible.
Backward rotation
Type I
• COR: TMJ.
• Increase in anterior facial height.
• Normal mandible.
Type II
• COR: most distal occluding molar.
• Condylar cartilage shows less growth than the rest
of the structures.
• Small vertical height of the ramus.
• This pattern leads to chin rotation.

Effect of mandibular rotation on occlusion
Forward rotation
Increase
interpremolar and
intermolar angles
Posterior teeth more
upright
Lower anterior teeth
guided forward
Alveolar
prognathism
Mesial migration of
mandibular teeth
Lower anterior
crowding

Backward rotation
Premolars and
molars are inclined
forward
Small
Interpremolar and
intermolar angles
Important
consideration while
planning anchorage
Uprighted lower
teeth
Reducing alveolar
prognathism
Lower anterior
crowding

Facial forms and anatomic
basis of malocclusion
DOLICOCEPHALIC FACIAL FORM:
• Brain is long and relatively narrow.
• Basicranium more flat and longer.
• Nasomaxillary complex in a protrusive position relative to
mandible.
• Mandible – downward and backward rotation of entire mandible.
• Occlusal plane rotated to a downward-inclined plane.
• Retrognathic profile--- Class II molar relation.

BRACHYCEPHALIC FACIAL FORM
• Brain – rounder and wider.
• Basicranium more upright and short.
• Nasomaxillary complex is short horizontally.
• Retrusive maxilla and a more relatively prognathic
mandible.
• Prognathic profile, Class III molar relationship.
• Interrelationship among brain form, facial profile &
occlusal type predisposes --- facial form and
malocclusion.

Conclusion
• Growth of the craniofacial complex correlates
well with general growth of the body.
• Body growth can be individualised into the growth
of various functional complexes such as the
cranial vault, cranial base, nasomaxillary complex
and mandible.
• Individual bones grow by a variety of processes
such as sutural growth, symphyseal growth,
displacement and surface remodelling.
• The mandible is a peculiar bone, which behaves
like a long bone bent at both ends.

• Orthodontic therapeutic interventions and
prognosis are influenced by the growth status and
growth trend of a patient.
• For all orthodontic patients, growth assessment
should be carried out as routine and a due
consideration should be integrated on remaining
hard and soft tissue growth, pattern of growth,
sexual dimorphism of growth and growth with
aging in planning the treatment.
• Functional jaw orthodontic therapy takes
advantage of the remaining growth of the
craniofacial region to change, alter or redirect
growth of the developing jaws.

References
• Essentials of facial growth: Enlow and Hans.
• Handbook of orthodontics: Couborne and DiBiase.
• Orthodontics- Diagnosis and management of malocclusion
and dentofacial deformities: OP Kharbanda.
• Contemporary orthodontics: Proffit.

Post-natal Growth and development of face

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