• NEONATAL SKULL Has got 270 bones as compared to an adult

who has 206 bones. Skull bones in neonate are 45(due to

incomplete ossification),adults have 22. Frontal bones at birth is in two halves,which

fuses at 2 years. There are two parietal bones. Occipital bone at birth consists of 4

pieces,fuses by 3-4 years of life. Mastoid process is asbsent in neonate,thus

stylomastoid foramen lies superficial.

Mid point : mid-point of stature of a two-month-old embryo is at chest , close to chin.

At birth : This may shift to just above umbilicus. In adults : It is at pubic-symphysis region. Lengths of head doubles by adulthood, but rest of body

grows still more, hence at birth 22% of body area is covered by head.

This decreases to 13% at 12 years and only 10% in an adult.

There is an axis of increased growth extending from head towards feet.

In a newborn child height is measured using a measuring tape in a lying down position and hence it is referred to as LENGTH.

Normal value of length in new born child is 45-50 cm.

The newborn is usually kept in a supine posture but can be literally ‘folded’ to its most comfortable posture i.e., posture simulating fetal posture of partial flexion.

Mild lordosis and protuberance of abdomen is a common finding at 2-3 years of age , but this disappears by 4 years.

Neck is relatively short at birth and its muscles are not developed for supporting the head.

Functional development of these muscles begins from two months onwards.

The girth of chest at birth is smaller than head circumference.

It becomes equal at 2 years and 15 years its ratio becomes 3:2.

Final ratio in adults is 5:3.

The chest is rounded in newborn.

Its final shape is attained by the time puberty is reached.

The umbilicus of a newborn is shed-off around 12th to 15th day.

The umbilicus is everted and in some cases umbilical hernia may be present.

At this stage abdomen is equal to chest until two years.

After two years the abdominal circumferences is less than the chest’s.

At birth: Legs are short , arms long. Arms : Birth to 2 years-length increases by 6.57%. At 8 years-50% longer than at two years By 16 to 18 years-slow growth , increases

development takes place , thus an early maturer has shorter arms than a late maturer.

Legs: At birth-short and curved. Birth to 2 years-length increases 40%.A lot of fat

on medial aspect of foot gives appearance of a flat foot. 6 years-straight , knock-knee and flat foot

appearance gets corrected. 8 years-50% longer than at birth. Adloescence-4 times longer than birth.

At birth : head circumference is around 35 cm

Head shape is rounded but sometimes it may get molded during parturition as over-riding of parietal bone takes place when head gets engaged in birth canal.

Six months : increases to 44 cm. One year : circumference may be more

than chest circumference. A total 4 inches increase takes place(2

inches first 4 months and then 2 inches next 8 months)

One year onwards : b/w 1 to 2 years 4 inches increase takes place.

o They bridge gap b/w bones that limit them.o Are made up of dura mater,the primitive periosteum and

aponeurosis from inside outwards.

FONTANELLES AT BIRTH

a) Anterior fontanelles , b/w 2 parietal bones and frontal bones.

b) Posterior fontanelle , b/w 2 parietal bones and occipital bone.

c) Sphenoid fontanelle , b/w frontal, parietal, temporal and sphenoid bone.

d) Mastoid fontanelle , b/w parietal , occipital and temporal bone.

1. Enables fetal skull to modify its size and shape as it passes through birth canal and permits rapid growth of brain during infancy.

2. Helps physician to gauge degree of brain development by their state of closure.

3. Anterior fontanelles serves as a landmark for withdrawal of blood for analysis from superior sagital sinus.

• Cranial synchondroses play an important role in craniofacial growth.

• Spenoccipital : closes by 17-20 years. sphenoethamoidal : closed by 2-4

years;may persists and fuse later in adolesence,but is of little importance in postnatal growth.

Mid sphenoid:close shortly after birth.

• Other synchondrosis : Intraoccipital Sphenopetrosal Petrooccipital.

At birth lower 3rd and middle 3rd of face are underdeveloped due to absence of teeth.

Forehead is high and bulging. Face of newly born baby is round and flat.

Eyes dominate and owing to absence of root of nose, appear to be widely separated.

Child’s convex facial profile is straightened out, owing to more anterior position of jaws.

Development of chin prominance and deeper position of eyes through growth of orbital ridges and ridge of nose enhances this impression.

• It is comparatively large in relation to small mouth.

• Tongue is flat, thin and blunt tipped, probably due to short frenum.

• Tongue , at this stage performs only one function, i.e.; acts as a piston while sucking.

REFLEXES PRESENT AT BIRTH

INTRODUCTION

• A REFLEX is defined as an involuntary, or automatic, action that your body does in response to something, without even having to think about it.

• Types of reflexes present at birth:

1.General body reflexes2.Facial reflexes3.Oral reflexes

MORO REFLEXES

• Any sudden movement of the neck initiates this reflex.

• A way of eliciting the reflex is to pull the baby half-way to sitting position from supine and suddenly let head fall back to a short distance.

• Reflex consists of rapid abduction and extension of arms with opening of hands.

CLINICAL SIGNIFICANCE

PALMER/ GRASP REFLEX

• When the baby’s palm is stimulated, the hand closes.

• There is also a corresponding planter reflex.

• Both normally disappear by 24 months.

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.

• It should have disappeared in 2-3 months and persistence may indicate the spastic form of cerebral palsy.

ASYMMETRIC TONIC NECK REFLEX• When the baby is at rest and

not crying, he lies at intervals with his head on one side, the arm extended to the same side, and often with a flexion of the contra lateral knee.

• This reflex normally disappears after 2 or 3 months, but may persist in spastic children.

PARACHUTE REFLEX

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.

• Absence of reflex occurs in hypotonia, hypertonia or severe mental abnormality.

FACIAL REFLEX

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 of cardiac output.

• Blood flow to skin, splanchic areas, muscles and kidney decreases, whereas the flow to the heart and brain is protected.

ORAL REFLEXES

ROOTING REFLEX

• When the infant’s cheek contacts the mother’s breast, the baby’s mouth results in vigorous sucking movements resulting in baby rooting for milk.

• When the corner of mouth is touched, the lower lip is lowered, the tongue moves towards the point stimulated.

• When the finger slides away, the head turns to follow it.

SUCKING

SWALLOWING

• Begins around 12 and half weeks IU life.

• Full swallowing and sucking is established by 32-36 weeks of IU life.

• Their absence in full-term baby would suggest a developmental defect.

GAG REFLEX

CRY

Conclusion

Appropriate knowledge of reflexes enables a paedodontist

to identify whether the child is developing normally or not

to identify whether development is going on at a proper rate or not

Knowledge of abnormalities if all reflexes are not proper

REFERENCE

• SHOBHA TONDON (FOR PEDIATRICS DENTISTRY) 2nd EDITION.