Pedologic Anatomy

PEDOLOGIC ANATOMY
SARANYA P THANKACHAN
FIRST YEAR PG
Dept. PEDODONTICS
&PREVENTIVE DENTISTRY

CONTENTS
 Definitions
 Introduction
 Fetal growth changes
 General post natal changes
in dimensions &
proportions
 Growth spurts
 Oral features of neonates
 External features of newly
born child
 Reflexes present at birth
 conclusion
 References

PEDOLOGY (children study)
 Pedology (paidology, paedology) is the study of children's behavior
and development (as distinct from pedagogy, the art or science of
teaching).
 G. Stanley Hall (1844-1924) fostered pedology as a separate study,
and also became instrumental in the development of modern
educational psychology.
 An American researcher, Oscar Chrisman, proposed the term
"pedology" in 1893.
Depaepe, M. (1992). "Experimental Research in Education 1890-1940: historical processes behind
the development of a discipline in western Europe and the United States." Aspects of Education,
Journal of the Institute of Education, University of Hull, 42, pp. 67-93.

PEDOLOGIC ANATOMY
THE AMERICAN HERITAGE® STEDMAN'S MEDICAL DICTIONARY COPYRIGHT © 2002, 2001,
1995 BY HOUGHTON MIFFLIN COMPANY. PUBLISHED BY HOUGHTON MIFFLIN COMPANY.
The study of the physical, mental, and social development and
characteristics of children.

INTRODUCTION
 A child may appear as a MINIATURE ADULT to a LAYMAN but the
detail anatomy reveals that he/she is completely different from an adult.
 The growth and development seems MIRACLE in growing child.
 These changes vary progressively till puberty after which permanent
features are established

NORMAL HUMAN GROWTH
PRE NATAL PHASES
The time from conception to birth is described in 3 phase
1.Period of ovum
2.Period of embryo
3.Period of fetes
Principles And Practice Of Pedodontics-3rd Edition- Aarathi Rao

PERIOD OF OVUM (CONCEPTION -10 DAYS )
 This period is from fertilization to implantation(up to 10-14 days)
 Rapid internal development is seen
 Implantation in the uterine wall occurs after about 10 days of fertilization

PERIOD OF EMBRYO -2-8- WEEKS
 Accessory apparatus like placenta , umbilical cord and amniotic sac develop during
this period
 External and internal features start to develop and function
 Sex can be identified
 Growth in the head region is proportionally much greater than the rest of the body
 By the end of this period the embryo measures 1 ½ to 2 inch length

PERIOD OF FETUS ( 8-40 WEEKS)
 Growth continues
 Nerve cells that are present since the third week , increase rapidly in number
during the second , third and fourth months
 Internal organs assume nearly adult positions by fifth lunar month

FETAL GROWTH CHANGES
END OF FIRST MONTH
Head flexed, neck longer and clearly defined
Development of face with upper lip and nostrils
The palate incompletely formed
Enamel organs formed from dental lamina.
The external ears and eyelids are developing and limbs are
forming.
TEXTBOOK OF PEDODONTICS- 3rd Edition-shobha Tandon

Skeletal and visceral tissue begins to form.
Kidney begins to form with tubules.
The back bone and vertebral canal form small buds that will
develop inner and upper extremities.
Heart forms , starts functioning and body system begins to
form.

END OF SECOND MONTH
Eyes are far apart with eyelids fused and nose flat.
Ossification begins and limbs becomes distinct as upper and lower.
Digits are well formed.
Major blood vessels forms.
Internal organs continue to develop

Eyes fully develop but eyelids still fused.
Bridge of nose develop and external ears are formed.
Ossification continues, nails develop.
Head flexion increases and neck becomes proportionately larger.
The umbilical protrusion of the gut is reduced with a proportionate abdominal
volume.
Heart beat is detectable.
END OF THIRD MONTH

Head is large in proportion to rest of the body.
Face takes on human features and hair appear on head.
Skin is bright pink.
Many bones are ossified and joints begins to form with continued development
of the body systems.
The eyes have moved forward to anterior position but are still wide apart.
The external ear is on the side of the head and no longer on upper part of the
neck.
END OF FOURTH MONTH

Head is less disproportionate to the rest of the body.
Fine lanugo hair covers the body.
Rapid development of body systems takes place.
Skin is bright pink and sebaceous glands become active
forming a cheesy covering over the skin.
Fetal movement called “quickening” can be seen
END OF FIFTH MONTH

Head becomes smaller but still less disproportionate to the rest of the
body.
Eyelids separate and eyelashes form.
Skin is wrinkled and pink.
Increase in growth of sebaceous and cutaneous tissue occur
END OF SIXTH MONTH

Head and body becomes more proportionate .
Skin is wrinkled and pink.
Eyebrow hair and eyelashes are developed.
Eyelid separate and the papillary membrane separate.
END OF SEVENTH MONTH
TEXTBOOK OF PEDODONTICS- 3rd Edition- Shobha Tandon

Sub-cutaneous fat deposition takes place.
Skin is less wrinkled.
Testes descends to scrotum.
There is progressive loss of lanugo, except of eyelid eyebrows and
scalp.
END OF EIGHTH MONTH

The shape of body is more infantile.
The thorax and abdomen broaden relative to head.
The umbilicus is gradually centrally located.
Chances of survival is much greater at this period.

Additional subcutaneous fat accumulates.
Lanugo sheds.
Nails extend to tip of finger and even beyond.
END OF NINTH MONTH

Significance in dentistry
 6th week of intrauterine life – tooth formation ( formation of primary epithelial band)
 7th week – primary epithelial band divides into a lingual process called dental lamina & a
buccal process called vestibular lamina
TIMELINE OF TOOTH DEVELOPMENT :
AGE DEVELOPMENTAL CHARECTERISTICS
42-48 days Dental lamina formation
55-56 days Bud stage – deciduous incisors; canine and
molars
14 weeks Bell stage of deciduous teeth;bud stage of
permanent teeth
18 weeks Dentin and functional ameloblast in deciduous
teeth
32 weeks Dentin and functional ameloblast in permanent
first molars
Orban’s textbook of oral histology and embryology

GENERAL POST NATAL CHANGES IN DIMENSIONS &
PROPORTIONS
Neonatal
skeleton
• Neonate – 270
• Ratio between
calvarial and
facial proportion
• Birth – 8:1
• Adult female –
2.5:1
• Adult male – 2:1
Textbook Of Human Anatomy By BD CHOURASIAS - 7th Edition- Volume 1

Frontal bone - at birth - two halves-fuses at 2 years.
Parietal bones – 2
Temporal bone – four parts – fuse by puberty
occipital bone - at birth - four pieces - fuse - 3-4 years
sphenoid bone - Fusion – 1year
Mastoid process - absent in the neonate
stylomastoid foramen lies superficial
Ethmoid bone – four parts – fuse by 5th or 6th year of life
Textbook Of Human Anatomy By BD CHOURASIAS - 7th Edition- Volume 1

BODY PROPORTIONS
 The body proportions are a result of the differential rates of growth of the cephalic
and caudal ends.
 Massive changes in the body proportion occur from the fetal life to adulthood.
MID POINT:
Chilander et al 1985,The mid point of the stature of a two month old embryo is at chest,
close to chin.
At Birth: This may shift to just above the umbilicus.
In Adult : It is at the pubic-symphysis region.

Textbook of orthodontics-Sreedhar premkumar

CEPHALO-CAUDAL GRADIENT
Cephalocaudal gradient of growth simply means that there is an axis of
increased growth extending from head towards the feet.
• The head takes up about 50% of the total body length around the third
month of intra uterine life.
• At the time of birth, the trunk and the limbs have grown more than the
head, thereby reducing the head to about 30% of body length.

 The overall pattern of growth continues with a progressive reduction in the relative
size of the head to about 12% in the adult.
 The lower limbs are rudimentary around the 2nd month of intrauterine life. They
later grow and represent almost 50% of the body length at adulthood
 There is increased gradient of growth evidence even within the head and face
 At birth, cranium is proportionally larger than face , Post natally the face grows more
than cranium.
 Mandible shows more growth than maxilla post natally
 In a new born child the height is measured using measuring tape in a laying position
and referred as LENGTH.[ 40-45 cm]

GROWTH SPURTS
 Growth does not occur uniformly throughout the life
 Certain period of life exhibit faster or more growth compare to
other periods
 This sudden increase in growth is termed as “growth spurts”
Etiology : physiological alteration in hormonal secretion
Orthodontics,the art and science , sixth edition- s j bhalaji

 Onset – sex linked
 Always appear earlier in girls
 Woodside (1968)in his study of Burlington group showed that a
neonatal growth spurt occurs at 3 years of age in both boys and
girls
 Juvenile/mixed dentition growth Spurt
 Girls 6-7yrs
Boys 7-9yrs
 Pre Pubertal/adolescent growth spurt
 Girls 10-11yrs
Boys 12–13yrs lasts for 2- 2 ½ years
 In girls menarche follows the peak velocity of growth spurt
Textbook Of Craniofacial growth- Sreedhar Premkumar

 Girls – 98% of growth completion – 16 ½ years
 Boys - 98% of growth completion – 18 years
 The reason that the average height of a female is less than that of a male,
male grow for a longer period of time during their adolescent growth spurt .
Textbook Of Craniofacial growth- Sreedhar Premkumar

Clinical significance of growth spurts
Pubertal increments in growth offer an ideal time for growth modification
procedure
Biological changes seen during puberty
• A lot of biological changes occur during the prepubertal growth period and
puberty,
• These biological changes differ with boys and girls
Manual of pediatric dentistry – Sreedhar premkumar

IN BOYS : IT COMPRISES OF FOUR STAGES
STAGE I – There is an initial fat spurt characterized by weight gain
This is due to the production of oestrogen before production of testosterone.
STAGE II - 1 year after stage 1
1) Sudden spurt in height gain
2) Development of secondary sexual characteristics
STAGE III – 8 – 10 months after stage II
1) Auxiliary hair growth begins
2) Facial hair appears on upper lip
3) It is also associated with a spurt in muscle growth

IN GIRLS : THERE ARE ONLY 3 STAGES
 STAGE 1 – It is the beginning of growth spurt
Appearance of secondary sexual characteristics
 STAGE II – Occurs after 1 year and coincides with peak
velocity in physical growth
 STAGE III – Appears 1 – 1 ½ years later stage II and is marked
by onset of menstruation

According to Bjork ,based on the variability in timing, a child can be grouped under one of
the following types:
 Average growers : They follow the middle range of the growth chart
comprises about two thirds of all children
 Early maturers : The onset of pubertal growth spurt is early in these patients.
They grow rapidly ; mature early ; completing their growth quickly
 Late maturers : They appear shorter than average during their childhood , since their
onset of their growth spurts are late , but eventually will grow into a average or even a
tall adult
 Myofunctional appliances are usually prescribed during these growth spurt periods
 Orthodontic surgeries such as done for correction of bimaxillary protrusion are done
preferably after cessation of growth , otherwise it may result in relapse and failure
Rao A. Principles and practice of pedodontics. JP Medical Ltd; 2012 Jul 20.

Ashraf soliman et al , 2016
 Puberty is a period of development characterized by partially
concurrent changes which includes growth acceleration, alteration in body
composition and appearance of secondary sex characteristics.
 The initiation, duration and amount of growth vary considerably during the
growth spurt.
 Adolescent growth spurt is the fast and intense increase in the rate of
growth in height and weight that occurs during the adolescent stage of the
human life cycle.
 This growth practically occurs in all of the long bones and most other
skeletal elements.
Soliman A, De Sanctis V, Elalaily R, Bedair S. Advances in pubertal growth and factors influencing it:
Can we increase pubertal growth?. Indian journal of endocrinology and metabolism. 2014 Nov;18(Suppl
1):S53.

Melmed S et al ,2012
 The pubertal growth spurt begins on average at 9-10.0 years for girls and
11-12.0 for boys, however there is considerable variation between
individuals and populations.
 The peak growth rate as well as the duration of this spurt is greater for
boys than for girls, and this accounts for the average difference of 11-13
cm in height between adult males and females.
 Up to 10% of clinically normally girls, usually those who sexually mature
at a late age, experience a reduced or absent growth spurt
Melmed S, Polonsky KS, Larsen PR, Kronenberg HM. Williams textbook of endocrinology.
Elsevier Health Sciences; 2015 Nov 30.

 Arthur B et al1985, ,Examination of median growth increments in cranial
base and mandibular dimensions finds pubertal growth spurts tending to
closely follow peak height velocity and the appearance of the ulnar
sesamoid.
 Franchi et al ,2000,One of the most important factors in orthodontic
treatment planning is the growth potential of the patient.
 Human growth and development are not uniform, with accelerations and
decelerations in the growth velocity of different skeletal components at
various developing maturational stages.
 The onset of puberty varies with sex, population, and the environment.
Franchi L, Baccetti T, McNamara J Jr. Mandibular growth as related to cervical vertebral maturation
and body height. Am J Orthod Dentofacial Orthop. 2000;118:335–340.

POSTURE
 The new born is usually kept in supine posture
 But can be literally folded to its most comfortable position i.e. The posture
simulating the fetal posture of partial flexion.
 Mild lordosis and protuberance of the abdomen is a common finding at 2-3
years of age
 Disappears by 4 years

THE NECK
 Neck - relatively short at birth and its muscles are not
developed for supporting the head.
 Functional development of the muscles begins after 2
months

THE CHEST
 The girth of the chest at birth is smaller than the head
circumference.
 It becomes equal by 2 years and by 15years its ratio becomes 3 : 2
 The final ratio in adult is 5 : 3
 The chest is rounded in newborn.
TEXTBOOK OF PEDODONTICS- 3rd Edition-Shobha Tandon

ABDOMEN
 The umbilicus of new born is shed off around12- 15day.
 The umbilicus is everted and in some cases umbilical hernia may be present.
 At this stage abdomen is quite protuberant but soft.
 Circumference of abdomen is equal to the chest until 2 years
 After 2 years abdominal circumference is less than the chest

EXTREMITIES
AT BIRTH: legs are short , arms long
ARMS
Birth – 2 years : length increase by 6.75%
At 8 years – 50% longer than at 2 years
By 16- 18 years – slow growth, increase development takes place.
LEGS
At birth: short & curved
Birth to 2 years: length increase by 40%
A lot of fat deposits on medial aspect of foot giving flat foot appearance
6 years: straight, the knock knee and flat foot gets corrected
8years: 50% longer than at 2 years
ADOLESCENCE: 4 times longer than birth Early mature : shorter legs than the late maturer
TEXTBOOK OF PEDODONTICS- 3rd Edition- shobha Tandon

CHANGES IN CRANIO FACIAL COMPLEX
 The skeletal portion of craniofacial complex develops as a blend of
morphogenesis of primary skull components.
1. The Neurocranium: it consists of two parts:
a) The desmocranium : comprise the vault of skull or calvarium .It
protects the brain and is formed of intra membranous bone.
b) The Chondrocranium: forms the base of skull which ossifies as an
endochondral bone.
2. The viscerocranium : formed by the bones of facial skeleton which
develop by intra membranous ossification which is derived from brachial
arches

DIMENSIONAL CHANGES IN CRANIO
FACIAL SKELETON
This changes can be appreciated even in intrauterine life.
3 month – Birth: the entire cranium becomes longer and wider in its relation to
height.
At birth:
• craniofacial skeleton undergoes changes between 30%-60% of its total growth.
• Head makes up about a greater part of total body length whereas in ,adult
accounts for about one- eighth of total body height.
Textbook of human anatomy by BD CHOURASIAS - 7th edition- volume 1

After birth: Size of cerebral cranium increase by about 50% while the facial skeleton
will grow more than twice the original size.
By 4 years: This growth is completed.
Cranial circumference increase from about 33cm [ birth] - 50cm [at 3 yrs]. After
which it only increase by 6cm.
After 4years onwards : Facial skeleton increases in all direction.
NOTE : Due to above craniofacial changes features of head and face are observed to
be different at different ages

HEAD
At Birth: The head circumference is around 35 cm.
6 months: It increases by 44 cm.
At 1 year: Head circumference may be more than chest circumference. A total 4
inches increase takes place.
1year onwards: 4 inches increment occurs between 1-2 years.
At 10 years: 95% of total head growth completes with the width of head
completed by 3years while the length of head completes by 17-18 yrs.

FONTANELLES PRESENT AT BIRTH:
 Fontanelles are a regular feature of infant development in which two segments of
bone remain separated, leaving an area of fibrous membrane or a “soft spot” that
acts to accommodate growth of the brain without compression by the skull.
 Of the six fontanelles in the human skull, the anterior fontanelle, located
between the frontal and parietal bones, serves as an important anatomical
diagnostic tool in the assessment of impairments of the skull and brain and
allows access to the brain and ventricles in the infant.
D’Antoni AV, Donaldson OI, Schmidt C, Macchi V, De Caro R, Oskouian RJ, Loukas M, Tubbs
RS. A comprehensive review of the anterior fontanelle: embryology, anatomy, and clinical
considerations. Child's Nervous System. 2017 Jun 1;33(6):909-14.

1. Anterior fontanelle: between two parietal bone & the frontal bone.
2. Posterior fontanelle: between two parietal bone and the occipital bone
3. Sphenoid fontanelle: between the frontal, parietal, temporal, sphenoid
bone.
4. Mastoid fontanelle: between parietal, occipital and the temporal bone

CLINICAL IMPORTANCE OF FONTANELLE :
Enables the fetal skull to modify its size and shape as it passes through the birth
canal and permits rapid growth of brain during infancy.
Helps the physician to assess the degree of brain development by their state of
closure.
Anterior Fontanelle serves as landmark for withdrawal of blood for analysis
from superior sagittal sinus.
Depressed levels of Fontanelle suggests dehydration and increased level
indicate increase in Intra-cranial pressure.

CLOSURE OF FONTANELLE:
a) Anterior Fontanelle [Frontal] : 18-24 months after birth.
b) Posterior Fontanelle [occipital]: 2 months after birth
c) Antero-lateral Fontanelle [Sphenoid] : 3 months after birth (paired)
d) Postero- lateral Fontanelle [mastoid]: begins to close 1-2 months after birth, closed
completely by 12 months

SUTURES OF CRANIUM
Cranial vault sutures, the fibrous tissues uniting the bones of the skull, are the
major sites of bone growth along the leading margins of the cranial bones during
craniofacial development, especially during rapid expansion of the neurocranium
(Baer, 1954).
 The cranial sutures are fibrous joints connecting the bones of the
skull..
 The dense fibrous tissue that connects the sutures is made mostly out
of collagen.
 These joints are fixed, immovable, and they have no cavity.
 They are also referred to as the synarthroses.
 In fetal skull the sutures are wide and allow slight movement during
birth, but later they become rigid and fixed just like in the adults.

1. Coronal Suture: between the frontal and parietal bone. Closes by 24-35 years
2. Sagittal suture: between two parietal bone. Closes by 22-30 years of age.
3. Lambdoidal Suture: Between two parietal and occipital bone. Closes by 29 years of
age.
4. Squamous Sutures and Lateral antero-posterior Sutures: between the squamous
portion of the temporal and parietal bone.
The squamous suture closes late in life.

FACE
At birth , lower third and the middle third of the face are under
developed due to the absence of the teeth.
The fore-head is high and bulging.
The face of the newly born baby is round and flat.
The eye dominate and owing to the absence of the root of the
nose, appear to be widely separated.
After the onset of the puberty the forehead flattens and widens,
lips thicken and face acquires an oval shape, mainly due to growth
of jaws.
The child convex profile is straightened out, owing to the more
anterior position of the jaws.

NASO-MAXILLARY COMPLEX
The maxilla develops in the membranous tissue at the end of the sixth fetal week.
The maxilla is attached to the neurocranium directly with the fronto maxillary
sutures and indirectly by means of various other facial structures such as the nasal,
lacrimal and ethmoid bones, nasal septum including vomer, palatine bones and
zygomatic arch.
Most of the structures mentioned above are joined together in an edged – edge
fashion.
During the early phase of fetal development the sagittal interrelation of the jaws is
characterised by Mandibular protrusion, which is gradually reversed.
At birth the maxilla is placed more anteriorly giving Class II relationship of the
jaws.

Later in course of post-natal development, both maxilla and mandible with their
associated soft tissues grow forward and downward and establish a normal Class I
relationship.
Maxillary sinus at birth are not well developed and present like slits.
Development of orbital cavities is practically complete at birth.
Nasal cavity is located between the two orbits of the eyes and its floor is roughly at
level with their bottoms.
The alveolar process can only be faintly discerned and the palate has a weak
transversal curvature.
The maxillary body is almost entirely filled with the developing teeth.

MANDIBLE
Although still separated by symphysis in the mid-line, the two halves of the mandible fuse
into a single bone by the age of 1-2 yrs.
AT BIRTH:
 The two rami are short.
 Condylar development is minimal.
 A thin line of fibrocartilage and connective tissue exists at the midline of the symphysis
to separate the right and left mandibular bodies.
 The symphysial cartilage is replaced by bone [ between 4 months of age –end of the 1
year].
 Growth is quite general, with all surface showing bone apposition, especially at the
alveolar border, distal and superior surface of the ramus, condyle, lower border and
lateral surface of the mandible.

 The alveolar process and the muscles are poorly developed at his age, so
that its basal arch mainly determines the shape of the mandible in the
neonate.
 At birth the structure of mandible is shell like with 10 alveolar sockets for
developing tooth germ.
 Of all the facial bones, the mandible shows not only the largest amount
of post-natal growth, but also the largest individual variation in
morphology.
 Angle of mandible is more obtuse in young children.

The position of the mandibular foramen
It changes by remodeling , to a more superior position from the occlusal plane as the
child matures into the adult.
 Very young child - foramen is below the occlusal plane
 Period of primary dentition - occlusal plane
 Adult - 7mm above the occlusal plane

TEMPEROMANDIBULAR JOINT [TMJ]
 The temporomandibular joints (TMJ) are the two
joints connecting the jawbone to the skull.
 It is a bilateral synovial articulation between the
temporal bone of the skull above and the mandible
below
STRUCTURE
 The main components are the joint capsule, articular
disc, mandibular condyles, articular surface of the
temporal bone, temporomandibular ligament,
stylomandibular ligament, sphenomandibular
ligament, and lateral pterygoid muscle.

Three phases of development are seen in the intrauterine life period
( Valasco Merida et al. 1999 )
 Blastemic Stage: 7-8 weeks of development corresponding to
the organization of condyle, articular disc and capsule
 Cavitation stage: 9-11 weeks of development corresponding to
the initial formation of inferior joint cavity and then start of
condylar chondrogenesis.
 Maturation stage: after 12 weeks of development

POST -NATAL CHANGES IN TMJ
 At birth the articular disc is flat and develops an accentuated S shaped
profile as the articular tubercle develops.
 Condylar cartilage is approximately 1.5 mm thick at birth, but soon thins
down to 0.5 mm.
 By 20-30 years of life it is completely replaced by endo-chondral
ossification.
 Mandibular condyle grows in a constant posterior, superior and lateral
direction and attains a mature contour by late mixed dentition period.

ORAL FEATURES OF NEONATES
 Alveolar process at the time of birth is gum pads
 Each gum pads divided into 10 segments by a transverse grooves.

Upper Gumpad
HORSESHOE SHAPED
Gingival Groove: separate gum pad from
palate.
Dental Groove: originates in incisive papillae
region and extends backwards to touch the
gingival groove in the canine region and then
laterally to end in the molar region.
Lateral Sulcus : is a deepened groove
separating canine and deciduous first molar
segments.

LOWER GUMPAD
“U” shaped, with its anterior portion everted labially.
Gingival groove- that demarcates the lingual extent of
gum pads.
Dental groove - running from the mandible backwards,
laterally to join the gingival groove in the canine region.
Lateral sulcus- deepened groove separating the canine
and deciduous first molar segments.

RELATIONSHIP OF GUMPADS
At rest gum pads are separated by the tongue lying over
the lower gum pad.
There is no definite antero-posterior relationship of the
gum pads on occlusion, but lower gum pad being smaller,
the lateral sulcus of the lower gum pads lies distal to that
of the upper.
There is no variable overjet with contact only in the first
molar segments.
During function the mandibular movements at this stage
are mainly vertical and to a very small extent in the
antero-posterior direction.
Lateral movement are absent.

During the early phase of fetal development the sagittal interrelationship of
the jaws is characterized by mandibular protrusion which is gradually
reversed.
At birth lower jaw is situated posteriorly.
This relationship has some significances i.e. disturbed post-natal forward
growth of development may result in malocclusion

Growth of Gum pads
At birth the width of gum pads are inadequate to accommodate all the
incisors.
The growth is rapid in first year after birth
Growth is more in transverse direction and in the labio-lingual
direction.
Due to the growth the segments of each gum pads become prominent.
Eruption of deciduous teeth commence at 6 months of age.

TONGUE
It is comparatively large in relation to the small mouth.
Then tongue is flat, thin and blunt tipped, probably due to
short frenum.
The tongue at this stage performs only one function, i.e.
acts as a piston while suckling.
Carlo WA. The newborn infant. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds.
Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 94.

TONSILS & ADENOIDS
 At birth: tonsils and adenoids are small in size.
 Clusters of yellow and white follicles with erythematous
border may appear initially.
 A few days after birth these may regress.
 First few months: the growth of tonsils and adenoids
takes place as lymphoid tissue starts proliferating and
establishing function.
 This growth is more in presence of infection.
Carlo WA. The newborn infant. In: Kliegman RM, Stanton BF, St. Geme JW,
Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA:

 6 months – 2 years: Maximum growth occurs as the primary physiological
enlargement.
 At 6 years: the next hypertrophy, after a period of quiescence, occurs
especially when the child is exposed to infection at school.
 This is secondary physiological enlargement.
 At puberty: the regression and atrophy of naso-pharyngeal lymphoid
tissue finally occurs by the time child attains puberty
Carlo WA. The new-born infant. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds.
Nelson Textbook of Paediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 94.

BUCCAL PAD OF FAT [CORPUS ADIPOSUM /
BICHAT’S FAT PAD]
 It is a child reserve of energy.
 child cheek prominence giving a chubby appearance.
 It is formed of a firm encapsulated mass of fat lying between the
subcutaneous fat and the muscle of the cheek.
 Its exact role in suckling is not known.
 It probably plays no role in suckling, but it has been found to regress
once suckling has ceased

OTHER EXTERNAL FEATURES OF
NEWLY BORN CHILD
 SKIN
 EYES
 NOSE
 LIPS
 EARS

SKIN
The skin of the neonate is often reddish.
A child may have an appearance of CYANOSIS due to thin skin and high
hemoglobin content of blood even when CO2 is high
A deep red purplish appearance may be result of transient anoxia resulting
from closed glottis prior to vigorous cry.
Deep red skin with fine soft immature lanugo hair is a characteristics of
premature infants.
Post-term infants may show whitish, peeling, parchment like skin.

EYES
Size: The eye of the neonate are small at birth, the size being
one third of the adult size.
Maximal growth occurs in 1 year and continues rapidly
decelerating rate till 3 years and further slows down till
puberty.
 Cornea: At birth, cornea is relatively more and nearly fills
the palpebral fissures.
 It reaches an adult size by 2years.
 After which the posterior aspect of the eyes grows ,giving
the eye ball its final spherical shape.

 The Lens: it is more or less spherical with greater refracting power
 The Fundus: It is less pigmented than adults.
It acquire its adult form by 4-6 months.
 The Retina: It has fine peppery mottling.
 The peripheral retina appears pale or greyish since peripheral
vasculature is immature.

NOSE
The nose of the neonate is small and flat with narrow nostrils.
The bridge of the nose is depressed.
Maximal growth of the nasal cartilage occurs till puberty,
after which it attains its final form.
The hair around the nose become thicker around the
puberty

LIPS
The lips of new born is reddish pink, soft and supple.
The midline of upper lip has a small projections, the labial
tubercle, which is said to disappear after cessation of suckling.
It may undergo slow transformation to form the transition
zone between the outer and inner aspect after one year.

EARS
The ears of child are almost developed.
The external auditory canal is short, straight and full of secretion.
The tympanic membrane has a dull grey translucency and the structures
of the middle ear can be easily studied through it.

REFLEXES PRESENT AT BIRTH
Reflex is an involuntary, or an automatic, action that your body does in response
to something, without even having to think about it.
 These are unconditioned reflexes and not learned or developed through
experience
 Normally developing newborn should respond to certain stimuli with these
reflexes

REFLEX ARC
Anatomical pathway for a reflex is called as reflex arc
It has 5 components :
Receptor
Afferent nerve
Center
Efferent nerve
Effector organ

The various reflexes are:
1. General Body
Reflexes
2. Facial Reflexes
3. Oral Reflexes

GENERAL BODY REFLEXES
1.MORO REFLEX
2. STARTLE REFLEX
3. PALMAR REFLEX/
GRASP REFLEX
4. WALKING/ STEPPING
REFLEX
5. LIMB PLACEMENT
REFLEX
6. ASYMMETRIC TONIC
REFLEX
7. BABINISKI’S REFLEX
8. PARACHUTE REFLEX
9. LANDAU REFLEX
10. TENDON REFLEX
11. ABDOMINAL
REFLEX

MORO’S REFLEXE
ELICITED BY :
PLACING THE
BABY IN SEMI
UPRIGHT
POSITION
SUDDEN DROPING
OF HEAD IN
RELATION TO
TRUNK
DISAPPEARS AT 3
TO 6 MTHS
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire
SC, Nowalk AJ, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia,
PA: Elsevier; 2018:chap 3

RESPONSE
Ø OPENING OF HAND
Ø EXTENSION AND ABDUTION OF UPPER
EXTRIMITIES
Ø ANTERIOR FLEXION OF UPPER EXTRIMITIES
Ø AUDIBLE CRY
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire
SC, Nowalk AJ, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed.
Philadelphia, PA: Elsevier; 2018:chap 3

CLINICAL IMPORTANCE:
 This reflex gives an indication of muscles tone.
 The response may be asymmetrical if muscle tone is unequal
on the two sides, or if there is a weakness of arm or an injury
to the humerus or clavicle
 Disappear - 2-3 months.
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC,
Nowalk AJ, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA:
Elsevier; 2018:chap 3

STARTLE REFLEX
It is variant of Moro’s Reflex.
Elicited by: sudden loud noise or by tapping the
sternum
Response is like Moro’s reflex but elbow remain
flexed and hands closed
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk
AJ, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier;
2018:chap 3

PALMER GRASP
 Elicited By: Placing finger or object in open palm of each hand
 Response: Infant grasp the object and with attempted removal grip
reinforced
 Appears at 28 weeks of gestation and
 Disappears at 2-3 months of life
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk
AJ, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier;
2018:chap 3

Clinical Significance:
 An exceptionally strong grasp reflex may be found in the spastic
form of cerebral palsy and in kernicterus.
 It may be asymmetrical in hemiplegia and in cases of cerebral
damage
 Persistence - spastic form of cerebral palsy.
Surveillance of Cerebral Palsy in Europe (SCPE) Collaborative Group. Surveillance of cerebral palsy in
Europe: a collaboration of cerebral palsy surveys and registers. Dev Med Child Neurol. 2000;42:816–24

WALKING / STEPPING REFLEX
 When the sole of the foot is pressed against the couch, the baby
tries to walk.
 It persists as voluntary standing
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk AJ, eds.
Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 3

Clinical significance
Premature infants will tend to walk in a toe-heel fashion
while more mature infants will walk in a heel-toe pattern.
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk AJ,
eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 3

ASYMMETRIC TONIC REFLEX
 When the baby is a rest and not crying, he lies at intervals
with his head on one side, the arm extended to the same
side, and often flexion of the contralateral knee.
 This reflex normally disappears after 2 or 3 months, but
may persists in spastic children

LIMB PLACEMENT REFLEX
 When the front of the leg below the knee, or the arm below the elbow is
brought in contact with the edge of table, the child lifts the limb over the edge.
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC,
Elsevier; 2018:chap 3

BABINSKI'S REFLEX
 Stroking of lateral surface of planter surface of the foot from the heel to
the toe results in flexion of the toe.
Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC, Nowalk AJ, eds. Zitelli and
Davis' Atlas of Pediatric Physical Diagnosis. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 3

PARACHUTE REFLEX
 It appears at about 6-9 months and persists there after.
 This reflex is elicited by holding the child in ventral suspension and suddenly
lowering him in the couch.
 The arms extended as a defensive reaction.

 In children with cerebral palsy, the reflex may be absent or
abnormal.
 It would be asymmetrical in spastic hemiplegia

LANDAU REFLEX
 It is seen in vertical suspension, with the head, spine and legs
extended.
 If the head is flexed, the hips , knees and the elbows also flex.
 It is normally present from 3 months and is difficult to elicit after 1
year.
Rennie JM, Huertas-Ceballos A, Boylan GB, et al. Neurological problems in the newborn. In: Rennie
JM, ed. Rennie and Roberton's Textbook of Neonatology. 5th ed. Philadelphia, PA: Elsevier Churchill
Livingstone; 2012:chap 40.

 Absence of reflex occurs in Hypotonia, hypertonia, or severe
mental abnormality

TENDON REFLEXES
 They are present in neonate.
 They are of great value for the diagnosis of cerebral palsy.
 In spastic children the tendon reflex are exaggerated.
Surveillance of Cerebral Palsy in Europe (SCPE) Collaborative Group. Surveillance of cerebral palsy in
Europe: a collaboration of cerebral palsy surveys and registers. Dev Med Child Neurol. 2000;42:816–24

FACIAL REFLEXES
• NASAL REFLEX
• BLINK REFLEX
• DOLLS EYE REFLEX
• CORNEAL REFLEX
• PUPIL REFLEXES

NASAL REFLEX
 Stimulation of the face or nasal cavity with water or local irritants produce apnea
in neonates.
 Breathing stops in expiration with laryngeal closure and infants exhibit
bradycardia and lowering the cardiac output.
 Blood flow to the skin splanchnic areas, muscles and kidney decrease, whereas
flow to the heart and brain is protected.
 Midwives have for many years blows on the face of neonates to induce the first
breathe.

BLINK REFLEX
 Various stimuli provoke blinking.
 Where the child is awake or asleep, pupils of the eye react to
change in intensity of light.

CORNEAL REFLEX
 It consists of blinking when the cornea is touched.
 The satisfactory demonstration of these reflex shows that the
stimulus, whether sound light or touch has been received, that
cerebral depression is unlikely, and that appropriate muscles can
contract in response.

DOLL’S EYE REFLEX
 Through a complex mechanism, infants hold
fixation of faces, movements or changing intensity
of light within their visual fields.
 When the infants head is slowly turned, the infant’s
eye will remain stationary
 During the first week they are able to maintain
these fixations against passive movement of their
bodies.

PUPIL REFLEXES
 The pupil reacts to the light but in the preterm baby and some full
term babies the duration of exposure to the light may have to be
prolonged to elicit the reflex.
 The light used should not be bright, for a bright light will cause
closure of the eyes.

ORAL REFLEXES
• ROOTING REFLEX
• SUCKING
• SWALLOWING
• GAG REFLEX
• CRY
• MASTICATION

ROOTING REFLEX
 When the infants cheek contact the mother’s breast,
the baby mouth results in vigorous sucking
movements resulting the baby rooting for milk.
 When corner of the mouth is touched, the lower lip is
lowered, the tongue moves toward the point
stimulated.
 When the finger slides away, the head turns to follow
it. When the center of the upper lip is stimulated, the
lips elevates.

Onset: 28 weeks IU
• Well established: 32- 34 weaks IU
• Disappear: 3-4 months
• Elicited by: the “rooting” or “search” reflex is present in normal
full term babies.

Persistence can interfere with sucking
Absence of this is seen in neurologically impaired
infants.

SUCKING
• Onset: 28 weeks IU
• Well established: 32-34 weeks IU
• Disappears: starting around 12 months
• Elicited by: It is tested by introducing a finger or teat into the mouth, when
vigorous sucking will occur.

Clinical significance :
Persistence may inhibit voluntary sucking
Sigmund Freud - Any kind of deprivation of the activity will
lead to fixation resulting in oral habits

SWALLOWING
 Onset: begins around 12 ½ weeks IU life.
 Full swallowing and sucking established 32-
36 weeks of IU life sucking & swallowing
reflexes are present in full term babies.
 Their absence in a full term baby would
suggest a developmental defect.

INFANTILE SWALLOW:
 Until the primary molars erupt, infants swallow with the jaws separated
and tongue thrust forward using facial muscles (Orbicularis oris &
Buccinator).
 This is non conditional congenital reflex.

ACQUIRED CONGINETAL REFLEX:
 After eruption of the posterior primary teeth, from the 18 months
of age onwards the child tends to swallow with the teeth brought
together by the masticatory muscles action, without a tongue
thrust.

GAG REFLEX(Pharyngeal reflex)
 It is seen in 18 ½ weeks. IU life.
 In the buccal cavity and pharynx, the ectoderm / endoderm zone
is towards the posterior third if the tongue.
 Touching here elicits a gag reflex, a protective reflex

Functional significance
It, along with reflexive pharyngeal swallowing, prevents something from
entering the throat except as part of normal swallowing and helps prevent choking
Absence of the gag reflex -- symptom of a number of severe medical conditions
1) Damage to the glossopharyngeal nerve, the vagus nerve,
2) Brain death.

CRY
 It is a non conditional reflex which accounts for its lack of individual
character and is of sporadic nature.
 Its starts as early as 21 - 29 weeks IU life.

Importance of cry
It is infant’s first verbal communication
Can be interpreted as a message of urgency or distress
Indicates:
Hunger
Pain
Discomfort

MASTICATION
 It is a conditioned reflex, learned initially by irregular and poorly
coordinated, chewing movements.
 The proprioceptive response of the TMJ and the periodontal ligament of
the erupting dentition establishes a stabilized chewing pattern, aligned
to the individual dental intercuspation.

IMPORTANTS OF NEONATAL REFLEXES
 Understanding the human development as a whole.
 Application for over all assessment of baby
 Recognition of possible neuro developmental damage in
prenatal and perinatal period.
 Establishment of the prognosis for future
 Predicting the Childs future potential

CONCLUSION
 Knowledge of PEDOLOGIC ANATOMY is very helpful to PEDODONTIST as
it not only serves as an adjunct in DIANOSIS but also aids in TREATMENT
PLANNING.
 The knowledge of different growth spurts helps in planning treatment especially
in Interceptive Orthodontics where growth can be modified or surgery is
indicated. [ e.g. Cleft lip & Palate]

 The knowledge of development of motor skills and language helps to
know whether development is going on proper rate or not.
 The knowledge of reflexes helps to identify whether child is developing
normally or not.
 It also helps to know what abnormalities child may be having if reflexes
are not proper.

REFERENCES
 TEXTBOOK OF PEDODONTICS- 3rd Edition- Shobha Tandon
 AJO-DO 1982 Oct (299-309): Maturation indicators and the pubertal growth spurt - Hägg
and Taranger
 Text book of orthodontics Kharbanda
 TEXTBOOK OF PEDIATRIC DENTISTRY- 4th Edition-nikhil Marwah
 Principles And Practice Of Pedodontics-3rd Edition- Aarathi Rao
 Textbook Of Craniofacial growth- Sreedhar Premkumar
 Manual of pediatric dentistry – Sreedhar premkumar
 Orthodontics , the Art And Science , Sixth Edition- S J Bhalaji
 Inderbir Singh’s Human Embryology-11th Edition
 Lewis AB, Roche AF, Wagner B. Pubertal spurts in cranial base and mandible: comparisons
within individuals. The Angle Orthodontist. 1985 Jan;55(1):17-30.

 Textbook Of Human Anatomy By BD CHOURASIAS - 7th Edition- Volume 1
 Orban’s textbook of oral histology and embryology
 Feldman HM, Chaves-Gnecco D. Developmental/behavioral pediatrics. In: Zitelli BJ, McIntire SC,
Elsevier; 2018:chap 3.
 Lehman RK, Schor NF. Neurologic evaluation. In: Kliegman RM, Stanton BF, St. Geme JW, Schor
NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 590.
 Rennie JM. Rennie & Roberton's Textbook of Neonatology E-Book: Expert Consult: Online and Print.
Elsevier Health Sciences; 2012 Sep 3.
 Surveillance of Cerebral Palsy in Europe (SCPE) Collaborative Group. Surveillance of cerebral
palsy in Europe: a collaboration of cerebral palsy surveys and registers. Dev Med Child Neurol.
2000;42:816–24
 Karen W Krigger. Cerebral Palsy: An Overview. American Family Physician. 2006;73(1):91–100.
 Soliman A, De Sanctis V, Elalaily R, Bedair S. Advances in pubertal growth and factors influencing
it: Can we increase pubertal growth?. Indian journal of endocrinology and metabolism. 2014
Nov;18(Suppl 1):S53.

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