basic concepts of growth and development of face and craniofacial structures, terminologies related and factors affecting it.

1. CONCEPTS OF GROWTH AND
DEVELOPMENT
Presented by:
Dr.Anjali Rajeshkumar Jaiswal
P.G. 1st year
Department of Orthodontics

2. CONTENTS
 Introduction
 Methods of studying growth
 Measuremental approach
 Experimental approach
 Basic tenets of Growth
 Pattern
 Variability
 Timing
 Terminologies related to growth

3. CONTENTS
Nature of skeletal growth
Endochondral
Intramembranous
Mechanisms of bone growth
Remodelling
Drift
Displacement
Factors affecting growth

4. Introduction
• Since dentists and orthodontists are heavily
involved in the development of not just the
dentition but the entire dentofacial complex, a
thorough background in craniofacial growth and
development is necessary.
• Growth usually refers to an increase in size or
number. It is largely an anatomic phenomenon.
• Development connotes an increase in degree of
organization; increase in complexity. It is
physiologic and behavioral.

5. GROWTH
• Growth is an increase in size- Todd
• The self multiplication of living substance- JX Huxley
• Increase in size, change in proportion and progressive
complexity- Krogman
• Entire series of sequential anatomic and physiological
changes taking place from the beginning of prenatal
life to senility- Meredith
• Quantitative aspect of biologic development per unit of
time- Moyers
• Change in any morphological parameter which is
measurable- Moss

6. DEVELOPMENT
• Development is progress towards maturity-
Todd
• All natural occurring unidirectional changes in
the life of an individual from the existence as a
single cell to its elaboration as a
multifunctional unit terminating in death-
Moyers

7. Methods of studying physical growth
• Measurement approach
1) Craniometry
2) Anthropometry
3) Cephalometric radiography
4) Three dimensional imaging
• Experimental approach
1) Vital staining
2) Autoradiography
3) Implant radiography

8. Craniometry
• It is based on the measurements of skulls found
among human skeletal remains.
• It was originally used to study the Neanderthal
and Cro-Magon peoples whose skulls were found
in European caves in the 18th and 19th centuries.
• It has been possible to piece together a great deal
of knowledge about extinct populations and to
get some idea of their pattern of growth by
comparing one skull with another.

10. • Advantage- precise measurements can be
made on dry skulls
• Disadvantage- all growth data must be cross-
sectional; the same individual can be
measured at only one point in time.

11. Anthropometry
• Measure skeletal dimensions on living individuals.
• Various landmarks established in the studies of
dry skulls are measured in the living individuals
simply by using soft tissue points overlying these
bony landmarks.
• E.g.: length of the cranium
– From a point at the bridge of the nose to a point at
the greatest convexity of the rear of the skull.
– Can be made on a dried skull or living individual.
– Results would be different because of soft tissue
thickness overlying both landmarks.

13. • Advantage-
– Subject not damaged
– longitudinal data produced
– makes it possible to follow the growth of an
individual directly, making the same
measurements repeatedly at different times.
• Disadvantage- soft tissue overlying the bony
landmarks introduces variations

14. Cephalometric radiography
• The technique depends on precisely orienting
the head in a cephalostat before making a
radiograph, with equally precise control of
magnification.
• Growth studies are done by superimposing a
tracing or digital model of a later on an earlier
one, so that changes can be measured.

16. • Advantage-
– Both location and amount of growth can be
observed
– Combines the advantage of craniometry and
anthropometry
– Allows the same individual to be followed over
time
• Disadvantage- it produces a 2-dimensional
representation of a 3-dimensional structure

17. Three dimensional imaging
• Computed tomography (CT) allows 3-D
reconstruction of the cranium and face.
• Magnetic resonance imaging (MRI) also
provides 3-D images with the advantage that
there is no radiation exposure.

18. CT scan MRI scan

19. Vital staining
• Introduced by John Hunter in the 18th century.
• Dyes that stain mineralizing tissues (or
occasionally, soft tissues) are injected into the
animal.
• These dyes remain in the bones and teeth and
can be detected later after sacrifice of the
animal.
• Examples of stains are: alizarin S, procion,
tetracycline, tryphan blue, fluorochrome.

20. • Alizarin strongly reacts with calcium at sites
where bone calcification is occurring.
• Since these are the sites of active skeletal
growth, the dye marks the locations at which
active growth was occurring when it was
injected.

22. Autoradiography
• The gamma-emitting isotope 99mTc can be
used to detect areas of rapid bone growth in
humans.
• These radioactive materials can be detected
by placing a film emulsion over a thin section
of tissue containing the isotope and then
exposing in the dark by the radiation.

24. Implant radiography
• It was developed by professor Arne Bjork and
coworkers.
• Inert metal pins are placed in bones anywhere in the
skeleton, including face and jaw.
• The metal pins become permanently incorporated in
the bones in the absence of infection or inflammation.
• Superimposing the cephalometric radiographs on
implanted pins allows precise observation of both
changes in the position of one bone relative to another
and changes in the external contours of individual
bones.

25. Sites of implantation
• In Mandible
– Symphysis in the midline below roots
– Right body of the mandible: one below the first
premolar and another below first molar
– Outer surface of ramus on right side in the level of
occlusal plane
– Left body of the mandible (under second premolar
or first molar)
– Using small pins on the right side and larger ones
on the left, the can be recognized easily.

27. • In Maxilla
– Inferior to anterior nasal spine
– Bilaterally in the zygomatic process
• In hard palate
– Behind canines
– Front of first molar in the junction between
alveolar process and palate

29. Basic tenets of growth
• Pattern
• Variability
• Timing

30. Growth: Pattern
• Pattern reflects proportionality.
• Pattern in growth is still more complex, because it
refers not just to a set of proportional relationship at a
point in time, but to the change in these proportional
relationship over time.
• The physical arrangement of the body at any one time
is a pattern of spatially proportioned parts. There is a
higher level pattern, the pattern of growth, which
refers to the changes in these spatial proportions over
time.
 Growth pattern: i) Cephalocaudal growth gradient
ii) Scammon’s growth curve

31. Cephalocaudal growth gradient
• There is an axis of increased growth extending from
the head towards the feet.
Changes in
the overall
body
proportions
during
normal
growth and
development
.

32. • In fetal life- about the third month of intrauterine
development, head occupies 50% of the total
body length and the head the cranium is larger
relative to the face. The trunk and limbs are
rudimentary.
• At birth:
– head- 39% of total body length
– Legs- 1/3rd of total body length
• In adults:
– Head-12% of total body length
– Legs- ½ of the total body length
• Therefore, with growth, trunk and limbs grow
faster than the head and face

33. Cephalocaudal growth in face
• At birth, the face
(nasomaxillary complex and
mandible) is less developed,
with the cranium representing
more than half of the total
head.
• Maxilla being closer to the
brain/head grows faster and
its growth is completed before
mandibular growth.
• Mandible being away from the
brain, completes its growth
later than the maxilla.
Changes in proportions of
craniofacial region.

34. Scammon’s growth curve
The body tissues can be
broadly classified into
four types.
a. Neural tissue
b. Lymphoid tissue
c. General tissue
d. Genital tissue
Different tissues in the body grow at different times and different rates.
Therefore, the amount of growth accomplished at a particular age is variable.

35. • Neural tissues complete 90% of their growth by 6
yrs and 96% by 10 yrs of age.
• Lymphoid tissues reach 100% adult size by 7 yrs:
proliferate far beyond the adult size in late
childhood (200% by 14 yrs) and involute around
the onset of puberty.
• Somatic tissues show an S-shape curve with the
definite slowing of growth rate during childhood
and acceleration at puberty going on till age 20.
• Growth of the genital tissues accelerate rapidly
around the onset of puberty.

36. Effect of Scammon’s growth in facial
region
• The maxilla follows neural growth pattern and its
growth ceases earlier in life.
• Skeletal problems of the maxilla should be treated
earlier than that of mandible. Eg: growth modification
procedures (facemask) should be given earlier in life
(6yrs) to promote growth of maxilla.
• Mandibular growth follows general growth pattern. Its
growth occurs until about 18-20yrs. Growth
modification treatment (chin cup) should be extended
until cessation of mandibular growth so as to prevent
relapse of class III malocclusion due to continued
growth of mandible.

37. Growth: Variability
• Everyone is not alike in the way that they
grow.
• Variability indicates the degree of difference
between two growing individuals in all four
planes of space including the all-important
time.
• One way to express variability quantitatively is
to evaluate a given child relative to peers on a
standard growth chart.

38. Standard growth chart
• An individual who stood
exactly at midpoint of
normal distribution would
fall along the 50% line of
the graph.
• One who was larger than
90% of the population
would plot above the
90%line.
• One who was smaller
than 90% of the
population would plot
below the 10% line.

39. Application of growth chart
• Location of an individual relative to the group can
be established.
• Used to follow a child over time to evaluate
whether there is an unexpected change in growth
pattern.
• Therefore if the position of an individual relative
to his or her peer group changes and especially if
the changes are marked the clinician should
suspect some growth abnormalities and should
investigate further.

40. Growth: Timing
• Variation in timing arises because the same event
happens for different individuals at different times; the
biologic clock of different individuals is set differently.
• Some children grow rapidly and mature early,
completing their growth quickly and thereby appearing
on the high side of developmental charts until their
growth ceases and their contemporaries begin to
catch-up.
• Others grow and develop slowly and so appear behind,
even though, given time, they will catch up with and
even surpass children who once were larger.

43. Growth spurts
• There are periods of sudden accelerated
growth interspersed with periods of relative
quiescence.
• Such rapid increase in growth rate is termed s
“growth spurt”.
• The timing of growth spurts differ in boys and
girls. Generally, girls precede boys by
approximately 2yrs.

44. Name of spurt Female Male
Infantile/ childhood
growth spurt
3yrs 3yrs
Mixed dentition/
juvenile growth spurt
6-7yrs 7-9yrs
Pre-pubertal/
adolescent growth spurt
11-12yrs 14-15yrs

45. Clinical significance
• To differentiate whether growth changes are
normal or abnormal.
• Treatment of skeletal discrepancies(eg: class II) is
more advantageous if carried out in the mixed
dentition period, especially during growth spurt.
• Arch expansion is carried out during maximum
growth period.
• Orthognathic surgery should be carried out after
the growth ceases.

46. Terminologies related to growth
• Growth fields
• Growth sites
• Growth centers

47. Growth fields
• The outside and inside surfaces of bone are
blanketed by soft tissues, cartilage or
osteogenic membranes.
• Within this, blanket areas are known as
growth fields, which are spread all along the
bone in mosaic pattern, responsible for
producing alteration in the growing bone.
• They have either depository or resorptive
activity.

49. Growth sites
• A site of growth is merely a location at which
growth occurs.
– E.g.: mandibular condyle, maxillary tuberosity
• Show marked response to external influences.
• Do not control the overall growth of the bone.

50. • Sutures of the face
(a,b,c,d,f)
• Mandibular condyle (e)
• Maxillary tuberosity (h)
• All synchondrosis of
cranial base (i)
• Alveolar bone (g)

51. Growth centers
• Growth centre is a location at which
independent (genetically controlled) growth
occurs.
• These are special growth sites which control
the overall growth of bone.
• Respond to functional needs, however show
little response to external influences.
• All centers of growth are sites, but the
converse is not true.

53. Growth at cellular level
• At cellular level, there are three possibilities of
growth.
– Hypertrophy- increase in the size of individual cell
– Hyperplasia- increase in the number of cells
– Secrete extracellular material- thus contributing to an
increase in size independent of the number or size of
cells themselves.
• Secretion of extracellular material is particularly
important in the growth of skeletal system as it
later mineralizes.

54. Growth at tissue level
• Interstitial growth:
– Combination of hypertrophy and hyperplasia
– Occurs at all points within the tissue
– Not possible after mineralization
• Appositional growth:
– Direct addition of new bone to the surface of
existing bone

55. Modes of bone formation
• Endochondral ossification
• Intramembranous ossification
– Bones developed from endochondral ossification
are referred to as cartilagenous bones
– Bones formed by intramembranous ossification
are called membranous bones

56. Endochondral ossification

57. Endochondral ossification
Mesenchymal
condensation
• At site of bone formation
Chondroblast
• Mesenchymal cells differentiate
into chondroblast
• Lay down hyaline cartilage
Perichondrium
• Surrounds cartilage
• Highly vascular
• Contains osteogenic cells

58. Calcification
• Intercellular substance calcified due to
influence of alkaline phosphatase secreted
by cartilage cells
Primary
areolae
• Cell death due to nutrition cut off
• Forms empty spaces called primary areolae
Secondary
areola
• Blood vessels and osteogenic cells invade
calcified matrix which is reduced to bars
and walls due to eating away of matrix
• Leaves large empty spaces

59. Osteoblast
• Cells from perichondrium become
osteoblast
• Arrange along surface of secondary areolae
Osteoid
• Laid down by osteoblast
• Gets calcified to form lamellar bone
Continued
apposition
• Another layer of osteoid secreted
• Goes on to form bone

61. Intramembranous ossification
Mesenchymal cells aggregate at the
site of bone formation
Soma lay down collagen fibers and
some form osteoblasts
Osteoblasts secrete gelatinous matrix
called osteoid around collagen fibers

62. Deposit Ca salts into osteoid
Osteoid bone lamella
Osteoblast move away from lamella
New layer of osteoid secreted and
calcified
Some osteoblasts get entrapped into
lamellae called osteocytes

63. Modes of ossification of the bones of
the skull
Endochondral Intramembranous Both
•Ethmoid
•Inferior nasal conchae
•Sphenoidal base
•Petrous part of temporal
bone
•Occipital basalis
•Malleus
•Incus
•Stapes
•Maxilla
•Zygomatic bone
•Palatine bone
•Vomer
•Lacrimal bone
•Frontal bone
•Parietal bone
•Squamous and
petrous part of
temporal bone
•Squamous occipitalis
•Occipital
•Sphenoid
•Temporal
•Mandible

64. Mechanisms of bone growth
• Bone remodeling
• Cortical drift
• Displacement
– Primary
– secondary

65. Bone remodeling
• Remodeling is a process of reshaping and
resizing each level within a growing bone as it
is relocated sequentially into a successions of
new levels.
• It is differential growth activity involving
deposition and resorption on the inner and
outer surfaces of bone.

66. Downward relocation of whole palate
Ramus remodeled- bone at the tip of the
condyle at an early age can be found at the
anterior surface of ramus.

67. Types of bone remodelling
• Biomechanical remodelling:
– At molecular level
– Constant deposition and removal of ions to maintain blood
calcium levels and carryout other homeostasis functions.
• Harvesian remodelling:
– Secondary reconstruction of bone
– Rebuilding of cancellous trabecular
• Traumatic remodelling:
– Regeneration and reconstruction of bone
• Growth remodelling:
– Change in size and shape of bone
– Change in proportion and relationship of bone with adjacent
structures

68. Cortical drift
• A combination of bone deposition and
resorption resulting in a growth movement
towards the depositing surface is called as
cortical drift.
– Rate of deposition and resorption equal- thickness
remains constant
– Deposition exceeds resorption- thickness
gradually increases
– Resorption exceeds deposition- thickness
decreases

69. combination of bone deposition and
resorption resulting in a growth
movement towards the depositing surface

70. Displacement
• It is a 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 the
overall size at the same time.
• Two kinds of displacement:
– Primary displacement
– Secondary displacement

72. Primary displacement
• Bone gets displaced as a
result of its own growth

73. Secondary displacement
• Bone gets displaced as a
result of growth and
enlargement of an
adjacent bone.

74. Factors affecting physical growth
• Genetic
• Growth hormones and growth factors
• Nutrition
• Illness
• Race
• Socio-economic status
• Secular trends
• Season and circadian rhythm
• Psychological stress
• Family size and birth order
• Exercise

75. Genetic
• The genes have the basic control of growth
including rate, timing and magnitude.
• However, the final outcome depends on the
interaction between the genetic potential and
environmental factors.
• The homeobox gene is important in the
establishment of body plan, pattern formation
and morphogenesis.
• The whole family of transforming growth factor-
beta genes is known to be important in
regulating cell growth and organ development.

76. Twin study
• Useful in study of population genetics.
• Began in 1870’s by Sir Francis Galton-article stating that
nature was a stronger factor than nurture in
determining respective characteristics of twins.
• This method is one of the most effective methods
available for investigating genetically determined
variables in orthodontics as well as in other medical
fields, depending on the variance in the shape and the
size of skull and teeth on genetic and environmental
influences.
• Twins:
– Monozygotic
– Dizygotic

77. • Markovic (1992)
– Carried out cephalometric study of 114 class II div 2
malocclusions, 48 twin pairs and 6 sets of triplets.
– MZ twins- 100% concordance
– DZ twins- 90% discordant
• Evidence from study by Lauweryns et al, 1995 has
indicated strong genetic influence in masticatory
muscle pattern in class II div 2 malocclusion.

78. • Schulze and Weise 1965, studied mandibular
prognathism in MZ and DZ twins and reported
that concordance in MZ twins was 6 times higher.
• Watnick 1972
– Studied 35 pairs of MZ and 35 pairs of DZ like-sexed
twins using lateral cephalogram.
– He concluded that certain areas such as the lingual
symphysis, lateral surface of ramus and frontal
curvature of mandible are predominantly under
genetic control.
– Other areas such as antegonial notch are
predominantly affected by environmental factors.

79. • Various developmental dental disorders,
which are under the influence of genes,
include
– Hypodontia
– Supernumerary teeth
– Abnormal tooth shape
– Submerged primary molars
– Ectopic eruption and transposition of canines

80. • Grahnen in 1956 in his familial and twin studies
concluded that in children with missing teeth, upto half
of their siblings or parents also had missing teeth.
• Dermaut and Smith in 1986 studied the prevalence of
tooth agenesis correlated with jaw relationship and
dental crowding in 185 patients and found that
hypodontia occurred more often in girls than in boys.
• Alvesalo and Portin 1992 found that missing and
malformed lateral incisors may be result of a common
gene defect.
• Helpin and Ducan 1986 found that in MZ twins there is
high rate of concordance of submerged primary
molars.

81. • Robert S. Corruccini, Rosario Potter
– Conducted a study on the occlusal characteristics in
32 pairs of monozygotic twins and 28 pairs of dizygotic
twins using stone casts.
– They studied arch shape, size, and symmetry, overjet,
overbite, posterior cross bite, buccal segment relation,
rotations and displacement.
– They concluded that arch size variation, tooth
displacement and cross bite showed significant
genetic variance. They also concluded an increased
environmental component of variance in occlusion.

82. Growth hormones and factors
• All tissues respond to growth hormone and
produce a proportional body growth that slows
after puberty when secretion of hormone
decreases.
• Growth factors affecting growth
– Insulin like growth factor- I and II
– Platelet derived growth factor
– Epidermal growth factor
– Vascular endothelial growth factor
– Transforming growth factor

83. Hypopituitarism
• Before puberty, the hypofunctioning of pituitary
leads to dwarfism (growth hormone deficiency).
• Clinical manifestation:
– Eruption rate and shedding time of teeth delayed, as
in the growth of body in general.
– Clinical crowns appear smaller than normal.
– Roots of teeth are shorter than normal.
– Dental arch is smaller than normal, cannot
accommodate all the teeth, malocclusion develops.

84. Multiple retained deciduous teeth 74,75,85
Missing permanent teeth 32,33,34,45

85. OPG showing multiple unerupted
permanent teeth 13,14,23,32,33,34,45

86. Hyperpituitarism
• Leads to gigantism (before epiphysis of long bone
closed) or acromegaly (after epiphyseal closure)
• Gigantism:
– Broad enlarged nose, thick and furrowed skin
– Skeletal: frontal bossing and prognathic mandible
– May develop Class III malocclusion with interdental
spacing
– Hypercementosis is a common finding.
– Roots may be longer than normal.

88. • Acromegaly:
– Terminal phalanges of hands and feet become
large.
– Lips become thick.
– Tongue becomes enlarged and indentations on
the sides from pressure against teeth.
– Mandible becomes large (accelerated condylar
growth), prognathism may be extreme.
– Mandibular teeth usually tipped to buccal or labial
side, owing to enlargement of tongue.

89. Macroglosia – indentations on the lateral margins of the tongue

91. Hypothyroidism
• Base of the skull is shortened, leading to a retraction of
bridge of nose with flaring.
• Wide face, fails to develop in longitudinal direction.
• Mandible underdeveloped, maxilla overdeveloped.
• Dental changes, as reviewed by Hinrichs (presented 36
cases)
– Tongue enlarged by edema, may protrude continuously,
leading to malocclusion.
– Eruption rate of teeth delayed.
– Retained deciduous teeth.

92. Euryprosopic facial form with
puffiness, periorbital swelling and
widened nasal bridge
Delayed fusion of intracranial
sutures

93. Multiple unerupted permanent teeth, with incomplete apexogenesis.

94. Delayed fusion of
epiphysis and
diaphysis of radius
and ulna, with
non-ossification of
the seasamoid and
hook of hamate

95. Hyperthyroidism
• Alveolar atrophy in advanced cases.
• Shedding of deciduous teeth earlier than
normal.
• Eruption of permanent teeth greatly
accelerated.
• Wide-eyed face

97. Parathyroid
• Hyperparathyroidism
– According to Schour and Massler, malocclusion caused
by sudden drifting with definite spacing of teeth.
• Hypoparathyroidism
– Altered tooth eruption pattern
– Short, blunted roots
– Enamel hypoplasia and dentin dysplasia
– Impacted teeth
– Partial anodontia

98. Reduced cortical width
of mandible in
hyperparathyroidism
Complete loss of lamina dura

99. Growth factors
• Proteins that bind to receptors on cell surface,
with primary result of activating cellular
proliferation and/or differentiation.
• Can be growth stimulators or inhibitors.
• Effect mediated through surface receptors on
target cells.
• Effect of growth factors is regulated through a
complex system of feedback loops, which involve
other growth factors, enzymes and binding
proteins.

100. Growth factors Effects
Fibroblast GF Increase osteoblastic precursor
population and also increase collagen
synthesis
Insulin-like GF Increase bone cell proliferation and total
protein synthesis
Transforming GF
Platelet derived GF
Increase proliferation of osteoprogenitor
and total protein synthesis
Interleukin 1 At low doses, it stimulates collagen
synthesis but is inhibitor in higher
concentrations.

101. Nutrition
• Malnutrition may affect all aspects of growth
including size of parts, body proportions, quality
and texture of tissues, and onset of growth
events.
• The effects of malnutrition are reversible to a
certain extent. If the adverse effects are not too
severe, the growth process accelerates when
proper nutrition is provided. This is called catch-
up growth.

102. Protein Energy malnutrition
• Spectrum of disease
– Kwashiorkor: deficiency of proteins
– Marasmus: severe and prolonged restriction of food
– Marasmic kwashiorkor: clinical features of both
disorders
• Some children adapt to this by nutritional
dwarfism
• Has higher incidence in India, south east Asia,
parts of Africa, Middle East, South and Central
America

103. Marasmus
• Greater clinical importance than Kwashiorkar
• Retarded growth
• Loss of weight
• Wasting of muscles
• Pigmentation changes in skin
• Hypotension
• Weakness
• Edema

105. Kwoshiorkar
• Child’s weight well below standard for age; may be
masked by edema due to hypoalbuminemia
• Child prone to infections
• Physical stunting
• Overall growth and growth of jaws decreased
• Eruption delayed, incisor and molar growth retarded
• Enamel exhibit increased acid solubility
• Increased dental caries
• Gingival and periodontal membranes exhibit
degeneration.

107. Avitaminosis
• Vitamin A deficiency:
– Enamel forming cells are disturbed, enamel matrix
arrested or poorly defined, calcification is
disturbed, enamel hypoplasia results.
– Dentin is atypical in structure, lacking normal
tubular arrangement and containing cellular and
vascular inclusions.
– Higher caries scores
– Eruption rate retarded
– Alveolar bone retarded in its rate of formation

108. Enamel hypoplasia- enamel forming cells disturbed

109. • Vitamin D deficiency:
– Cessation of calcification of epiphysial disks.
– Developmental abnormalities of dentine and
enamel
– Delayed eruption
– Misalignment of teeth in the jaws
– Higher caries index

110. Developmental
abnormalities of
dentin and
enamel
Delayed eruption
Misalignment of
teeth

111. • Vitamin C deficiency:
– Atrophy and disorganization of odontoblasts-
irregularly laid down dentin with few, irregularly
arranged tubules.
– Atrophic changes of alveolar bone.
– Scurvy- interdental and marginal gingiva bright red,
swollen, boggy, ulcerated and bleeds
– Severe chronic cases- swelling of periodontal
membranes occur, followed by loss of bone and
loosening of teeth.
• Riboflavin deficiency:
– Affects nasolabial folds and alae nasi, which exhibit
scaly greasy dermatits.

113. Illness
• Illness can be generally due to nutritional
deficiencies, and also due to compromised
immunity.
• Chronic illness can lead to growth retardation,
either because of illness itself, or because of
treatments required for it.
• Long term administration of systemic
corticosteroids (for treating bowel disease,
asthma, cystic fibrosis, bone marrow transplant,
etc) is a major cause of impaired growth.

114. Maternal illness can also
adversely affect the fetal growth

115. Psychological conditions
• It is seen that children experiencing stressful conditions
display an inhibition of growth hormone secretion.
Hence can markedly retard growth.
• Emotional distress and worry interferes with digestion
and elimination, disturbs sleep, and affects circulation.
• Continued over a long period of childhood might affect
growth.
• E.g.: marked retardation in growth seen in French and
German children during and immediately after the First
World War
• Short stature is also commonly perceived to be
associated with social and psychological disadvantage.

116. Family size and birth order
• Studies show that first born babies tend to
weigh less at birth and have smaller stature,
but better I.Q.
• The smaller the family size, better will be the
nutrition and other favourable conditions.

117. Socioeconomic factors
• Children brought up in affluent and favourable
socio-economic conditions show earlier onset of
growth events.
• They also grow to a larger size than those living in
unfavourable socioeconomic environment.
• Elementary school children in slums have been
found to average 3 to 5 inches shorter and 8 to 12
pounds lighter than children from good
neighbourhoods.

118. poor throughout
comfortable throughout94
96
98
100
102
104
106
1928-29
1929-30
1930-31
1931-32
1932-33
poor throughout
comfortable, then poor
comfortable throughout
Relative weight of children aged 6-9 yrs, acc to economic status of family:
(a) Family in comfortable circumstances throughout period
(b) Family in comfortable circumstances in 1929, becoming poor by 1932
(c) Family in poor circumstances throughout period
From Palmer and Collins [33]

120. Regional distribution of the number of children under 5 yrs in millions
(A)Stunted
(B)Living in poverty
(C)Disadvantaged

121. Race
• There seems to be some evidence that race
does play a role in growth process.
• For example in American Blacks, calcification
and eruption of teeth occurs almost a year
earlier than their White counterparts.
• Although it can be attributed to other
nutritional and environmental factors.

123. Secular trends
• Changes in size and maturation in a large
population can be shown to occur with time.
• For example: 15 yr old boys are approximately
5 inches taller than the same age group 50 yrs
back.
• It could possibly be due to changes in socio-
economic conditions and food habits.
• Although children are growing at a faster rate,
they are also stopping growth sooner.

126. Season and circadian rhythm
• Seasonal variation have been shown to affect adipose tissue
content and weight of new born babies.
• Growth in height is faster in spring than in autumn, whereas
weight growth is faster in autumn.
• Growth in height and eruption of teeth appears to be greater
at night than in the daytime due to fluctuations in the
hormone release.

127. Exercise
• Development of motor skills and increase in
muscle mass is found to be influenced by
exercise.
• An exercise-associated GH secretion is a response
to acute or prolonged exercise-induced fuel
shortage that directs the metabolism towards
utilization of lipids and promotes growth.
• Exercise provides the necessary mechanical stress
for growth and remodelling of the
musculoskeletal system.