The document discusses various reflexes seen in infants and their significance. It begins by defining a reflex and describing the basic reflex arc involving receptors, afferent nerves, centers, efferent nerves and effectors. Reflexes are then classified based on whether they are inborn or acquired, their neurological pathway, purpose and clinical presentation. Several important reflexes seen in newborns like the moro, rooting and babinski reflexes are explained in detail. The document emphasizes that assessment of infant reflexes helps identify normal development and potential abnormalities.
3. Introduction
A reflex is an involuntary or automatic action that your
body does in response to something without even
having to think about it
Neonatal reflexes – inborn reflexes present at birth &
occur in a predictable fashion
Normally developing newborn should respond to
certain stimuli with these reflexes
4. Reflex arc
Anatomical pathway for a reflex is
called as reflex arc
It has 5 components :
Receptor
Afferent nerve
Center
Efferent nerve
Effector organ
5. Classification of reflexes
Depending upon whether inborn or acquired
Unconditioned reflexes, inborn reflex
Conditioned reflexes/acquired reflexes
6. Depending upon the situation of the center
Cerebellar reflexes
Cortical reflex
Midbrain reflex
Bulbar or medullary reflexes
Spinal reflexes
7. Depending upon the purpose
Protective/flexor reflexes
Antigravity/extensor reflexes
Depending upon clinical basis
Superficial reflexes
Mucus membrane
Cutaneous reflex
Deep reflexes
Visceral reflexes
Pathological reflexes
8. Significance of reflexes
Helps a paedodontist to identify whether the child is
developing normally or not
Tells about what abnormalities the child may be
having if all reflexes are not proper
Knowledge of development of motor skills – helps to
identify whether development is going on at a proper
rate or not
13. General body reflexes
Moro reflex/ startle reflex
Begins at 28 weeks of gestation
Initiated by any sudden movement of
the neck
Elicited by -- pulling the baby halfway
to sitting position from supine &
suddenly let the head fall back
Consists of rapid abduction & extension
of arms with the opening of hands,
tensing of the back muscles, flexion of
the legs and crying
14. Within moments, the arms come together again
Clinical significance
Its nature gives an indication of muscle tone
Failure of the arms to move freely or the hands to open
fully indicates hypotonia.
It fades rapidly and is not normally elicited after 6
months of age.
15. Palmar/grasp reflex
Begins at 32 weeks of gestation
Light touch of the palm produces
reflex flexion of the fingers
Most effective way -- slide the
stimulating object, such as a finger
or pencil, across the palm from the
lateral border
Disappears at 3-4 months
Replaced by voluntary grasp at 45
months
16. Clinical significance
Exceptionally strong grasp reflex -- spastic form of cerebral
palsy & Kernicterus
May be asymmetrical in hemiplagia & in cases of cerebral
damage
Persistence beyond 3-4 months indicate spastic form of
palsy
17. Plantar/grasp reflex
Placing object or finger beneath the
toes causes curling of toes around the
object
Present at 32 weeks of gestation
Disappears at 9-12 months
• Clinical significance :
This reflex is referred to as the
"readiness tester".
Integrates at the same time that
independent gait first becomes
possible.
18. Walking/stepping
reflex
When sole of foot is pressed
against the couch, baby tries to
walk
Legs prance up & down as if baby
is walking or dancing
Present at birth, disappears at
approx 2-4 months
With daily practice of reflex,
infants may walk alone at 10
months
20. Limb placement reflex
When the front of the leg below the
knee or the arm below the elbow is
brought into contact with the edge
of a table, child lifts the limbs over
the edge
Present at birth, fades away rapidly
in early months of life
• Clinical significance
Reflex is readily demonstrable in the
newborn and persistent failure to
elicit it at this stage, is thought to
indicate neurological abnormality
21. Withdrawal reflex
Protective reflex
Stimulus : a pinprick or a sharp
painful stimulus to sole of foot
Response : flexion & withdrawal of
stimulated leg
Present at birth, persists throughout
life
Clinical significance – Absence of
this is seen in neurologically impaired
infants.
22. Asymmetric tonic neck reflex
Most evident between 2-3 months of age
• Clinical significance
The reflex fades rapidly and is not normally
seen after 6 months of age.
Persistence is the most frequently observed
abnormality of the infantile reflexes in
infants with neurological lesions
Greatly disrupts development
23. Symmetric tonic neck
reflex
Extension of the head causes
extension of the fore limbs and
flexion of the hind limbs
Evident between 2-3 months of age
Clinical significance
Not normally easily seen or elicited in
normal infants
May be seen in an exaggerated form
in many children with cerebral palsy.
24. Babinski’s reflex
Stimulus consists of a firm painful stroke
along the lateral border of the sole from heel
to toe
Response consists of movement (flexion or
extension) of the big toe and sometimes
movement (fanning) of the other toes
Present at birth, disappears at approx 9-10
months
Presence of reflex later may indicate disease
25. Babkin reflex
Deep pressure applied simultaneously
to the palms of both hands while the
infant is in supine position
Stimulus is followed by flexion or
forward bowing of the head, opening of
the mouth and closing of the eyes
Fades rapidly and normally cannot be
elicited after 4 months of age.
26. • Clinical significance
Reflex can be demonstrated in the newborn, thus showing
a hand-mouth neurological link, even at that early stage
27. Parachute reflex
Reflex appears at about 6-9 months &
persists thereafter
Elicited by holding the child in ventral
suspension & suddenly lowering him to the
couch
Arms extend as a defensive reaction
• Clinical significance
Absent or abnormal in children with
cerebral palsy
Would be asymmetrical in spastic
hemiplagia
28. Landau reflex
Seen in horizontal suspension with the
head, legs & spine extended
If the head is flexed, hip knees &
elbows also flex
Appears at approximately 3 months,
disappears at 12-24 months
• Clinical significance
Absence of reflex occurs in hypotonia,
hypertonia or mental abnormality
29. Trunk incurvation reflex
Stroking one side of spinal column
while baby is on his abdomen causes
Crawling motion with legs
Lifting head from surface
Present in utero, seen at
approximately 3rd or 4th day
Persists for 2-3 months
30. Gallant’s reflex
Firm sharp stimulation along sides of
the spine with the fingernails or a pin
produces contraction of the underlying
muscles and curving of the back.
Response is easily seen when the infant
is held upright and the trunk
movement is unrestricted
Best seen in the neonatal period and
thereafter gradually fades.
31. Tendon reflexes
Simple monosynaptic reflexes, which are elicited by a
sudden stretch of a muscle tendon
Occurs when the tendon is tapped
Present throughout life
33. Clinical significance
Useful diagnostically for :
Detection of upper motor neuron lesions (exaggerated
response)
Myopathic conditions (depressed or absent response)
Localization of the segmental lesions of the cord.
34. Tonic labyrinthine reflex
Labyrinths -- most important organs
concerned with the development of
anti-gravity postures and balance
Movement of the head in any
dimension stimulates the labyrinths;
and produces the appropriate
responses
Arms & legs extend when head moves
backwards, & will curl in when the
head moves forward
Emerges in utero until approximately
4 months postnatally
35. Facial reflexes
Nasal reflex
Stimulation of the face or nasal cavity with water or local
irritants produces apnea in neonates
Breathing stops in expiration with laryngeal closure in
infants – bradycardia & lowering of cardiac output
Blood flow to skin, splanchnic areas muscles & kidney
decreases
Flow to the heart & brain remains protected
36. Blink reflex
A bright light suddenly shone into the eyes, a puff of air
upon the sensitive cornea or a sudden loud noise will
produce immediate blinking of the eyes
Purpose – to protect the eyes from foreign bodies & bright
light
May be associated tensing of the neck muscles, turning of
the head away from the stimulus, frowning and crying
Reflexes are easily seen in the neonate and continue to be
present throughout life
37. Clinical significance
Examination is a part of some neurological exams,
particularly when evaluating coma
Satisfactory demonstration of these reflexes indicate –
No cerebral depression
Contraction of appropriate muscles in response
38. Doll’s eye reflex
(Oculocephalic reflex)
Passive turning of the head of
the newborn leaves the eye
“behind”
A distinct time lag occurs before
the eyes move to a new position
in keeping with the head position
Disappears at within a week or
two of birth
Failure of this reflex to appear
indicates a cerebral lesion
Head
Eye
39. Auditory orienting reflex
A sudden loud and unpleasant noise :
May produce the blink reflex
Infant may remain still and show increased alertness
Quieter sounds usually cause reflex eye and head turning to the
side of the sound, as if to locate it
Seen first at about 4 months of age
Thereafter, head turning towards sound stimuli occurs and the
accuracy of localization increases rapidly by 9-10 months
40. Clinical significance
Reflex responses are made use of in tests of infants for
hearing loss
Pattern of the localization responses indicates the level of
neurological maturity
41. Oral reflexes
Rooting reflex
Baby’s cheek is stroked :
They respond by turning their head
towards the stimulus
They start sucking, thus allowing for
breast feeding
When corner of mouth is touched, lower
lip is lowered, tongue moves towards the
point stimulated
When finger slides away, head turns to
follow it
When center of lip is stimulated, lip
elevates
42. Onset -- 28 weeks IU
Well established – 32-34 weeks IU
Disappears – 3-4 months
Clinical significance
Persistence can interfere with sucking
Absence of this is seen in neurologically impaired
infants.
43. Sucking / Swallowing
reflex
Touching lips or placing something in
baby’s mouth causes baby to draw
liquid into mouth by creating vacuum
with lips, cheeks & tongue
Onset – 28 weeks IU
Well established – 32-34weeks IU
Disappears around 12 months
44. Clinical significance :
Persistence may inhibit voluntary sucking
Sigmund Freud - Any kind of deprivation of the
activity will lead to fixation resulting in oral habits
45. Gag reflex
(Pharyngeal reflex)
Seen in 19 weeks of IU life
Reflex contraction of the back
of the throat
Evoked by touching the roof of
the mouth, the back of the
tongue, the area around the
tonsils and the back of the
throat
46. Functional significance
It, along with reflexive pharyngeal swallowing, prevents
something from entering the throat except as part of
normal swallowing and helps prevent choking
Clinical significance
Absence of the gag reflex -- symptom of a number of
severe medical conditions :
Damage to the glossopharyngeal nerve, the vagus nerve,
Brain death.
47. Cry reflex
Non conditioned reflex which
accounts for its lack of its
individual character
Sporadic in nature
Starts as early as 21-29 weeks of IU
life
48. Importance of cry
It is infant’s first verbal communication
Can be interpreted as a message of urgency or distress
Indicates:
Hunger
Pain
Discomfort
49. 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
50.
51. References
Shobha Tandon. Textbook of Paedodontics
MS Muthu. Paediatric Dentistry, Principals & practice