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2. •INTRODUCTION
•DEFINITIONS
•FACTORS AFFECTING GROWTH
•GROWTH:CONCEPTS,METHODS OF GATHERING
DATA AND STUDYING GROWTH
•BONE DEVELOPMENT AND GROWTH
•THEORIES OF GROWTH
•PRENATAL GROWTH AND DEVELOPMENT OF MAXILLA
•POST NATAL GROWTH AND DEVELOPMENT OF MAXILLA
•DEVELOPMENT OF THE PALATE
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3. DEFINITIONS OF GROWTH
• J.S.Huxely: The self multiplication of living
substance.
• Krogman:Increase in size, change in proportion
and progressive complexity.
• Todd:An increase in size.
• Meridith:Entire series of sequential anatomic and
phisiologic changes taking place from beginning
of prenatal life to senility.
• Moyers:Quantitative aspect of biologic
development per unit time.
• Moss: Change in any morphological parameter
which is measurable.
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4. DEFINITIONS OF
DEVELOPEMENT
• Todd:Development is progress towards maturity.
• Moyers: Development refers to all the naturally
occuring unidirectional changes in the life of an
individual from its existence as a single cell to its
elobaration as a multifunctional unit terminating
in death. Thus it encompasses the normal
sequential events between fertilization and death.
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5. FACTORS AFFECTING
PHYSICAL GROWTH
• Heredity
• Nutrition
• Illness
• Race
• Race
• Socioeconomic factors
• Family size and birth order
• Secular trends
• Climatic and seasonal effects
• Psychological disturbances
• Exercise www.indiandentalacademy.com
16. THEORIES OF GROWTH AND
DEVELOPMENT
• Genetic theory
• Sutural theory
• Cartilagenous theory
• Functional matrix theory
• Van Limborgh’s theory
• Enlow’s expanding “V” principle
• Enlow’s Counterpart principle
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17. PRENATAL DEVELOPMENT
OF THE MAXILLA
The prenatal life may be divided into three periods :
The period of the ovum [fertilization to the end of fourteenth
day]
The period of the embryo [14th
to 56th
day ]
The period of the foetus [56th
to Birth ]
THE PERIOD OF OVUM:
This period consists primarily of cleavage of the ovum and
attachment to the uterine wall . At the end of this period the
ovum is only 1.5 mm in length and cephalad differention has
not yet begun. www.indiandentalacademy.com
18. THE PERIOD OF THE EMBRYO:
This period is charecterised by the following events:
Formation of the three germ layers
Formation of the pharyngeal arches
Differentiation of the mesenchyme to signal beginning
of endochondral and intramembranous bone formation
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19. FORMATION OF THE THREE GERM LAYERS
The blastocyst [day 5 ] has cells arranged in two layers :
1.The outer cell mass which will form the trophoblast
2.The inner cell mass which will give rise to the embryo
proper “embryoblast”
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21. --At the 8th
day of development the trophoblast has differenti
ated into two layers:
Inner layer: Cytotrophoblast
Outer layer:Syncytiotrophoblast
The cells of embryoblast also differentiate into two layers:
---A layer of small cuboidal cells : hypoblast
---A layer of high columnar cells : epiblast
The hypoblast and the epiblast together constitute the
bilaminar germ disc
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23. --A small cavity is formed within the epiblast . This is
called the AMNIOTIC CAVITY
--Around the 13th
day of development the following
structures are seen:
Secondary yolk sac
Extraembryonic coelom [ Chorionic cavity ]
Connecting stalk [ Future embryonic stalk ]
Prochordal plate [ Where the epiblast cells are firmly
attached to the hypoblast cells ……The future
Buccopharyngeal membrane ]
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25. During the 3rd
week there is appearance of the “primitive
streak” with the “ primitive node”
In the region of the node and the streak, the epiblast cells
invaginate a new cell layer between the hypoblast [ now
called the ENDODERM ] and the epiblast [now called the
ECTODERM]
This third layer is called the MESODERM
The process of mesoderm formation is called the
GASTRULATION
These cells form a tube like process called the
NOTOCHORDAL PROCESS which gets filled in by cells to
form the NOTOCHORD
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26. Notochord forms the midline axis which serves as the basis
for axial skeleton . It extends from the prochordal plate in
the cephalic region to the cloacal membrane in the region
caudal to the primitive streak .
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29. ECTODERM MESODERM ENDODERM
Central Nervous System Myotome {muscle} Epithelial lining for GIT,
Respiratory tract and
Bladder.
Peripheral Nervous System Sclerotome {Cartilage and
Bone}
Parenchyma of tonsil,
thyroid,parathyroid,thymus
,liver and pancreas.
Sensory Epithelium of the
Ear, Nose and Eye
Dermatome {Subcutaneous
tissue of skin}
Epithelial lining of
tympanic cavity and
Eustachian tube
Skin, Hair, Nails Vascular System
Pituitary, Mammary and
Sweat Glands
Uro-genital System
{excluding the bladder}
Enamel of the Tooth Spleen and Supra Renal
glands
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30. THE NEURAL CREST CELLS
They give rise to
1. Sensory ganglia
2. Schawnn cells
3. Pigment cells
4. Odontoblasts
5. Meninges
6. Cartilage cells of branchial arches
They have a possible important function in the formation
of face
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33. When the embryo is 41/2 weeks old five mesenchymal
swellings can be recognized:
The Mandibular Swellings [ 1st
Pharyngeal Arch ]
The Maxillary Swellings [ Dorsal portion of 1st
Arch]
The Frontal Prominence
Each Pharyngeal Arch is thus characterized by its
own :
Muscular Component
Cranial Nerve Component
Arterial component
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35. The mesenchyme of the maxillary process subsequently
gives rise to the following:
Premaxilla
Maxilla
Zygomatic bone
Temporal bone in part
All these bones undergo intramembranous
ossification.
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38. BRANCHIAL AND
PHARYNGEAL ANOMOLIES
CONGENITAL AURICULAR SINUS AND CYSTS:
They are found in a triangular area of skin anterior to ear.
They are remnants of the 1st
branchial groove.
BRANCHIAL SINUSES:
Open on the side of the neck and result from the failure of
the 2nd
branchial groove to close. The blind pit or sinus
that remains opens along the anterior border of the
sternocleidomastoid.
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39. FORMATION OF THE
PHARYNGEAL ARCHES
The most typical feature in the development of the head and
neck is formed by the BRANCHIAL or the PHARYNGEAL
ARCHES
They appear in the 4th
and 5th
week of development and
contribute greately to the characteristic appearance of the
embryo.
With this a number of outpocketings the PHARYNGEAL
POUCHES appear along the lateral walls of the pharyngeal
gut-the most cranial part of the foregut.
At the end of 4th
week the centre of the face is formed
STOMODEUM ,surrounded by the first pair of pharyngeal
arches . www.indiandentalacademy.com
41. When the embryo is 4 ½ weeks old, five
mesenchymal swellings can be seen:
Two Mandibular Swellings [1st
Pharyngeal Arch ]
Two Maxillary Swellings[Dorsal Portion of the 1st
Arch]
The Frontal Prominence
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42. BRANCHIAL FISTULA:
It is a communication between the intratonsillar cleft and
the side of the neck- persistence of the 2nd
branchial
groove and the 2nd
pharyngeal pouch.
BRANCHIAL CYST:
Remnants of part of cervical sinus and/or the 2nd
branchial groove may persist and form this cyst …..it is
located along the anterior border of the
sternocleidomastoid.
FIRST ARCH SYNDROME:
Due to insufficient migration of the neural crest cells
into the 1st
arch. Some of the more common are:
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43. TREACHER COLLINS SYNDROME:
Malar hypoplasia
Antimongoloid palpebral fissures
Defects of lower eyelids
Deformed external ears
Abnormalities of middle and internal ears
PIEERE ROBIN SYNDROME:
Hypoplasia of mandible
Cleft palate
Defects of the eye and the ear
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45. CONTROL PROCESSES AND
FACTORS IN FACIAL GROWTH
VAN LIMBORGH’S CLASSIFICATION
Intrinsic genetic factors:Inherent in skeletal tissues
themselves.They exert influence inside the cell to which
they are inherent.
Local Epigenetic factors:Epigenesis includes the sum
total of all biochemical and biophysical events produced
by the functioning of the cells and organs ……Petrovic
General Epigenetic factors
Local environmental factors
General environmental factorswww.indiandentalacademy.com
46. LO CAL
G enetic controloriginating
from adjacent structure and provide localactions
Exam ple:Em bryonic induction influences sk. growth Brain,eye
G ENERAL
G enetic controloriginating from distant structure
and provide generalactions
Exam ple: Horm ones
EPIG ENETIC FACTO RS
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47. L O C A L
N o n g e n e tic in flu e n c e e v o k e d b y s tim u li
o rig in a tin g fro m e x te rn a l e n v iro n m e n t
E x a m p le :h a b its ,fo rc e s o f m u s c .c o n tra c tio n
G E N E R A L
T h e s e a re G e n e ra l n o n g e n e tic
in flu e n c e s
E x a m p le :N u tritio n ,fo o d ,o x y g e n .
E N V IR O N M E N T A L F A C T O R S
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48. THE CONTROL PROCESSES
THE GENETIC BLUE PRINT:
Genes have a fundamental and perhaps an overriding
influence in establishing basic facial pattern but they are
NOT exclusive determinants of all growth parameters.
BIOCHEMICAL FORCES:
The play of physical forces acting on a bone to regulate its
development, morphologic configuration, histological
structure and physical properties.
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49. WOLFF’S LAW: The architecture of bone is such that it can
best resist the forces that are brought to bear upon it with the
use of as little tissue as possible.
It has a flaw in that the law doesn’t distinguish between
physical forces acting on a bone and forces acting on the
osteogenic connective tissue that actually produce any
remodelling of the bone.
SUTURES,CONDYLES AND SYNCHONDROSES:
Growth,form and dimensions of a bone are governed by
intrinsic genetic programming residing within that bone’s
own bone –producing cells of periosteum,sutures and bone
related cartilages –provide inclusive growth regulation for
each of the whole bones they serve.
Modern research discounts such a concept .
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50. CONTROL MESSENGERS:
Growth control is essentially a localised developmental
process working with local function as it responds to
multiple developmental interplay with other growing parts.
FORCE/PRESSURE/TENSION
BIOPHYSICAL REACTIONS-Bone deformation,compression
of periodontal ligament,tissue injury
PRODUCTION OF FIRST MESSENGERS
Hormones[PTH],Prostaglandins,Neurotransmitters
PRODUCTION OF 2nd
MESSENGERS[Camp,Cgmp,Ca]
INCREASE IN CELLS OF RESORPTION/DEPOSITIONwww.indiandentalacademy.com
51. POSTNATAL GROWTH AND
DEVELOPMENT OF
MAXILLA
The growth of maxilla depends on influence of several
functional matrices that act upon different areas of the bone
thus allowing its subdivision into skeletal units:
The BASAL BODY beneath the INFRAORBITAL
NERVE, later surrounding it to form the infraorbital canal.
The ORBITAL UNIT responds to the growth of the eyeball
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52. The NASAL UNIT depends on the SEPTAL CARTILAGE
for its growth.
The TEETH provide the functional matrix for the
ALVEOLAR UNIT
The PNEUMATIC UNIT reflects maxillary sinus
expansion,which is more a responder than a determiner of the
skeletal unit.
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54. THE 3 PRINCIPLE REGIONS OF
FACIAL AND NEUROCRANIAL
DEVELOPMENT
THE BRAIN AND THE BASICRANIUM:
The above said determines the persons headform and type
Ex:A long and narrow basicranium gives rise to
dolicocephalic facial form while a brachycephalic facial
form gives a wider facial configuration
BASICRANIUM is the template that establishes the shape
and perimeter of the facial growth field.
THE AIRWAY:
The configuration and dimensions of the airway are a productwww.indiandentalacademy.com
57. of the composite growth of many hard and soft tissues
along its pathway from nares to glottis.
These parts are again dependent upon the airway for
maintanance of their own functional and anatomic position.
It functions as a key stone for the face.
THE ORAL REGION:
Compensatory adjustments by the remodelling process
occur throughout growth and development in many ways.
The oral region is one of the areas around which these
changes take place.
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58. A CORNERSTONE OF
GROWTH PROCESS
Remodelling
Displacement
REMODELLING:
Refers to a process where bone deposition and resorption
occur so as to bring about change in size , shape and
relationship of the bone .
FUNCTIONS OF REMODELLING:
Progressively create the changing size of bonewww.indiandentalacademy.com
60. Sequentially relocate each of the component regions of
the whole bone to allow for overall enlargement.
Shape the bone to accommodate its various functions
Provide fine tune fitting of all the separate bones to each
other and to their contiguous soft tissues.
DISPLACEMENT:
It is the physical movement of the whole bone and occurs
while the bone simultaneously remodels by resorption and
deposition.
Bone deposition doesn’t push the articular contact surface
of another bone and provide growth….rather bone is carried
by the expansive force of all growing soft tissues around it
and attached to it by anchoring fibres.
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63. PRIMARY DISPLACEMENT:
Movement of a bone because of its own growth .
SECONDARY DISPLACEMENT:
Movement of a bone passively or secondary to growth of
contiguous bone/s.
DRIFT:
The combination of bone deposition and resorption
resulting in a growth movement towards the depositing
surface is called drift.
RELOCATION:
The progressive sequential movement of component
parts as a bone enlarges is relocation.www.indiandentalacademy.com
64. THE GROWTH AND DEVELOPMENT OF THE
NASOMAXILLARY COMPLEX
The maxillary tuberosity and arch lengethening
The lacrimal suture-a key growth mediator.
The maxillary tuberosity and the key ridge
The vertical drift of teeth
The nasal airway
Palatal remodelling
Downward maxillary displacement
The cheekbone and the zygomatic arch
Orbital growth
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65. THE MAXILLARY TUBEROSITY AND ARCH
LENGETHINING:
The horizontal lengethening of maxilla is produced by
remodelling at the maxillary tuberosity
Back facing periosteum of tuberosity has continuous
deposits of new bone as long as srowth in this part
continues.
The lateral surface is also depositiory …the arch widens.
The endosteal side of the cortex is resorptive …the
maxillary sinus expands as a result.
The whole maxilla undergoes primary displacement in
an anterior and inferior direction as it grows.
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68. THE LACRIMAL SUTURE A KEY GROWTH MEDIATOR
The lacrimal bone is a diminutive flake of a bony island
which is surrounded by sutural connective tissue.
The sutural system of the lacrimal bone provides for the
slippage of multiple bones along sutural interfaces with the
pivotal lacrimal as they all enlarge differentially.
The lacrimal sutures allow maxilla to slide downward along
its orbital contacts which facilitates inferior displacement of
the maxilla.
THE MAXILLARY TUBEROSITY AND THE KEY RIDGE:
Major change occurs in surface contour along the vertical
crest below malar protruberance called the key ridge.
A reversal occurs here where by external surface of
maxillary arch anterior to it is resorptive.
Similarly reversal is seen at Point A as well.
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70. THE VERTICAL DRIFT OF TEETH: AN IMPORTANT
CLINICAL CONSIDERATION
The term vertical drift denotes the displacement of the
whole tooth along with its alveolar housing in an occlusal
direction.
As the jaws grow the dentition drifts both vertically and
horizontally to keep phase in the respective anatomic
positions.
THE NASAL AIRWAY
The lining surfaces of the bony walls and floor of the
nasal chambers are resorptive accept for the nasal side of
the olfactory fossae.
This produces a lateral and anteiror expansion of the
nasal chamber and a downward relocation of the palate.
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72. The breadth of the nasal bridge in the region just below
the frontonasal sutures does not markedly increase from
childhood to adult hood. More inferiorly in the inter
orbital area the medial wall of each orbit expands and
balloons out considerably in a lateral direction.
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74. PALATAL REMODELING
Even though the labial side of the whole anterior part of
the maxillary arch is resorptive, the arch none the less
increases in width and the palate becomes wider (the ‘V’
principle).
DOWNWARD MAXILLARY DISPLACEMENT
The primary displacement of the whole ethmomaxillary
complex in a downward direction is accompanied by
simultaneous remodeling in all areas.
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75. New bone added at the following sutures
-Frontomaxillary
-Zygotemporal
-Zygosphenoidal
-Zygomaxillary
-Ethmomaxillary
-Ethmofrontal
-Nasomaxillary
-Nasofrontal
-Frontolacrimal
-Palatine
-Vomerine www.indiandentalacademy.com
77. THE CHEEK BONE AND ZYGOMATIC ARCH
The posterior side of malar protuberance within the
temporal fossae is deposited in while the anterior
surface is resorptive. Thus the cheek bone relocate
posteriorly as it enlarges.
This results in a protrusive appearing nose and an
anteroposteriorly much deeper face.
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79. ORBITAL GROWTH
The remodeling changes in orbit are complex as it
comprises of a number of bones including
1. Maxilla
2. Ethmoid
3. Lacrymal
4. Frontal
5. Zygomatic
6. Greater and lesser wings of sphenoid
There is bone deposition along much of the walls of
the orbit except the lateral wall which is resorptive.
The orbit also grows by ‘V’ principle, so that the
cone shaped orbital cavity moves in a direction
towards its wide opening.
In the child the floor of nasal and orbital cavities are
at about the same level. But in the adult the nasalwww.indiandentalacademy.com
80. SEX DIFFERENCES
The females have
1. More upright and bulbous forehead
2. Lesser eyebrow ridges
3. Small and less protrusive nose
4. Lower nasal bridge
5. A more rounded nasal tip
6. Flatter face
7. Wider appearing face with more prominent appearing
cheek bones.
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81. DEVELOPMENT OF PALATE
The palate is formed from three components
a) The two palatal process
b) The primitive palate formed from frontonasal process.
The definitive palate is found by the fusion of these three
parts
The transition from vertical to horizontal position is
completed within hours.
Some of the mechanisms are
- Biochemical transformation in the physical consistency
of the connective tissue matrix of the shelves.
- Variation in vasculature and blood flow to this
structures
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82. - The sudden increase in tissue turgor
- Intrinsic shelf force
- Muscular movements
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87. ANAMOLIES OF PALATAL DEVELOPMENT
Epstein’s pearls and Bohn’s nodules
The entrapment of epithelial rests or pearls in the
line of fusion of the palatal shelves may give rise
to median palatal rests cysts.
II. Dental lamina cysts
Epithelial remnants of dental lamina that develop
on the crest of alveolar ridge.
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88. III. Torus palatinus:
IV. Oblique facial cleft
Failure of maxillary swelling to merge with its
corresponding lateral nasal swelling results in this
deformity.
V. Cleft lip and Palate
Successful fusion of the three embryonic components
of the palate involves complicated synchronization of
1. Shelf movements with growth
2. Withdrawal of the tongue
3. Growth of the mandible and headwww.indiandentalacademy.com
89. CLASSIFICATION OF CLEFT LIP AND PALATE
Davis and Ritchi (1922) and Veau (1931) have given the
following classification
Class I – Cleft of soft palate only
Class II – Cleft of hard and soft palate till the incisive
foramen
Class III – Complete unilateral cleft of the soft palate,
hard palate, the alveolar ridge and the lip on one side.
Class IV – Complete cleft of soft palate, hard palate,
alveolar ridge and the lip on both sides.
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91. INCIDENCE
Cleft lip : 1:1000 Births, More in males
Cleft palate : 1:2500 Births, More in females
PROSTHODONTIC TREATMENT
If it is decided the surgery will be unsuccessful for the
treatment of cleft soft palate then the first obturator is
given at 2 years
There are three types:
1. Fixed pharyngeal
2. Hinged pharyngeal
3. Meatal
The cleft of hard palate can be so easily covered by
means of a simple acrylic or metallic palate.www.indiandentalacademy.com
92. PHARYNGE
AL ARCH
NERVE MUSCLES SKELETON
Mandibular V-Mandibular div. Muscles of mastication, Ant.
Belly of Digastric,Tensor
Palatini,Tensor Tympani.
Incus,Malleus, Ant.
Ligament of
Malleus,Sphenomandibular
ligament ,Portion of
mandible.
Hyoid VII-Facial Muscles of facial expression,
Post. Belly of Digastric,
Stylohyoid,Stapedius.
Stapes,Styloid
process,Stylohyoid
Ligament, Smaller horn
and Superior body of
Hyoid.
III IX-Glossopharyngeal Stylopharyngeus Greater horn, Lower part
of Body of Hyoid.
IV-VI Sup.Laryngeal,
Rec.Laryngeal.
Muscles of Pharynx, Soft
Palate and Larynx.
Laryngeal Cartilages.
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93. ENDODERMAL POUCH DERIVATIVES
I Tubo tympanic recess-Auditory
tube,middle ear cavity,tympanic
antrum.
II Tonsil.
III Inferior Parathyroids,Thymus.
IV Sup.parathyroids.
V Ultimo Branchial body-
Parafollicular cells of thyroid.
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94. TIMING OF PRIMARY CLEFT LIP AND PALATE PROCEDURES.
{After Delaire}
CLEFT LIP ALONE
UNILATERAL
↓
One operation at 5-6 months.
BILATERAL
↓
One operation at 5-6 months.
CLEFT PALATE ALONE
SOFT PALATE
ALONE
↓
One operation at 5-6 months.
SOFT + HARD
PALATE
↓
Two operations
↓
Soft palate –6 months
↓
Hard palate- 12- 15 months
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95. CLEFT LIP AND PALATE
UNILATERAL
↓
Two operations
↓
Cleft lip + soft palate – 5-6 months
↓
Hard palate + gum pad +/- lip revision –
12-15 months
BILATERAL
↓
Two operations
↓
Cleft lip + soft palate – 5-6months
↓
Hard palate + gum pad +/- lip revision –
12-15 months
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