1. Definitions, Growth spurts & Diffrential growth
GROWTH & DEVELOPMENT
Definitions, Growth spurts & Diffrential growth
Dr. Ravi Shanthraj MDS PhD

2. Definition of Growth “Growth refers to increase in size” - Todd
“Growth usually refers to an increase in size
and number” – Proffit
“Self multiplication of living substance” J.S.Huxley.

3. “Growth may be defined as the normal change in the amount of living substance
“Change in any morphological parameter which is measurable”- Moss.

4. Definition of Development
Development is a progress towards maturity” – Todd
“Development connotes a maturational process involving progressive differentiation at the cellular and tissue levels” - Enlow

5. “Development refers to all naturally occurring progressive, unidirectional, sequential changes in the life of an individual from it’s existence as a single cell to it’s elaboration as a multifunctional unit terminating in death” – Moyers

6. Definitions
Morphogenesis – “A biologic process having an underlying control at the cellular and tissue levels”
Differentiation – “It is a change from generalized cells or tissues to a more specialized kinds during development”

7. Translocation – Maturation – “ It is a change in position”
“It is the emergence of personal characteristics and behavioural
phenomenon through growth processes”

8. Timing and sequential change
a. Prenatal growth
b. Postnatal growth
c. Maturity
d .Old age

9. Timing and sequential change
Prenatal growth- rapid increase in cell no.
Postnatal growth- 20 yrs- declining growth-increasing maturation
Maturity-period of stability
Old age
death

10. Different types of growth
Size change
Positional change
Proportional change
Functional change
Maturational change
Compositional change

11. Proportional change
Eg-Head of the infant
Functional change
Eg-Secretion , production of enzymes, hormones

12. Size change- height, weight, volume
Positional change-
Migration of neural crest cells
Eruption of teeth
Dropping of diaphragm

13. Maturational change
stability and adulthood
Compositional change
Eye pigmentation

14. Major themes of development
Changing complexity
Shifts from competent to fixation
Shifts from dependent to independent
Ubiquity of genetic control modulated by environment

15. Changing complexity
All level of organisation sub-cellular to whole organism
Complexity development
Orthodontics Mixed dentition period

16. Shifts from competent to fixation
Undifferentiated cells once differentiated become fixed.
Shifts from dependent to independent
Development brings greater independence at most levels of organisation.

17. Ubiquity of genetic control modulated by environment
Genetic control of development is constantly being modified by environmental interactions

18. eg- thymus gland after puberty
Growth
Increase in size decrease in size
eg- thymus gland after puberty
Development process of inc complexity
Development=growth+differenciation+translocation

19. Importance of growth and development to orthodontist
Etiology of malocclusion
Health and nutrition of children
comparison of growth

20. identification - abnormal occlusal development at an earlier stage
use of growth spurts
Surgery initiation
Planning of retention regime

21. Normal features of Growth & Development
pattern
-Differential Growth
-cephalocaudal gradient of growth
Variability
Timing, rate & direction

22. PATTERN
Pattern in growth represents proportionality .It refers not just to a set of proportional relationships at a point in time but to change in these proportional relationships over time
The physical arrangement of the body at any one time is a pattern of spatially proportioned parts.

23. DIFFERENTIAL GROWTH
Different organs grow at different rates amount and at different times.
Scammon’s curve of growth
-Richard scammon

24. SCAMMON’S CURVE OF GROWTH
LYMPHOID
NEURAL
GENERAL
GENITAL

26. CEPHALOCAUDAL GRADIENT OF GROWTH
Changes , part of normal growth pattern reflect “Cephalocaudal gradient of growth”
Axis of increased growth

27. CEPHALOCAUDAL GRADIENT OF GROWTH

28. Growth of head and face

29. It illustrates the change in overall body proportions during normal growth and development.
Imp aspect of pattern is its predictability.

30. Predictability
Predictability of growth pattern is a specific kind of proportionality that exists at a particular time and progresses towards another, at the next time frame with slight variations.
Change in growth pattern indicates some alteration in the expected changes in body proportions.

31. Variability
No two individuals with the exception of siamese twins are like.
Hence it is important to have a “normal variability” before categorizing people as normal or abnormal

32. Normality Normality refers to that which is usually
expected, is ordinarily seen or typical – Moyers
Normality may not necessarily be ideal.
Deviation from usual pattern can be used to express quantitative variability
This can be done by using “growth charts”

33. Timing of Growth One of the factors for variablity in growth.
Timing variations arise because biologic clock of different individuals is different.
It is influenced by:
genetics
sex related differences
physique related
environmental influences

34. Distance curve Vs Velocity curve
Height
Velocity curve
Age
Distance Curve (cumulative curve): In this curve growth can be plotted in height or weight recorded at various ages.
Velocity Curve(incremental curve): In this by amount of change in any given interval that is growth increment is plotted.

35. Growth spurts Defined as periods of growth acceleration Sex-linked
Normal spurts are
Infantile spurt – at 3 years age
Juvenile spurt – 7-8 years (females); 8-10 years (males)
Pubertal spurt – years(females); years (males)
Growth modulation can be done

37. GROWTH STUDIES AND METHODS OF STUDYING GROWTH.

38. Longitudinal growth studies
Methods of studying bone growth
Types of growth data
Methods of gathering growth data

39. Types of growth data . Opinion Observations. Ratings and rankings.
Quantitative measurements.
direct data.
indirect data.
derived data.

40. Types of growth data. Opinion clever guess based on experience.
crudest form of scientific knowledge.
Observations:
for studying all or none phenomenon
limited way use
quantitative data is must.

41. RATING
comparison
RANKING
value

42. Quantitative measurements:
Includes expressing an idea or fact as a meaningful quantity or numbers.
Direct data: measurements ,living persons or cadaver -measuring device.
Indirect data: images or reproductions of actual person.
Derived data comparing at least two measurements.

43. Methods of gathering growth data.
Longitudinal studies .
Cross sectional studies.
Overlapping or semi longitudinal studies.

44. Longitudinal studies.
measurements of same person or group- regular intervals through time.
Advantage: problems are smoothed with time,
Variability,serial comparison makes study of specific developmental pattern of individual possible.
Disadvantages: time consuming, expensive, sample loss or attrition,averaging.

45. Cross sectional studies
ADVANTAGES
repeating Quicker
Less costly
Statistical treatment made easier
DISADVANTAGES
Variation amongst individuals cannot be studied

46. Semi longitudinal studies.
Merger of either studies

47. LONGITUDINAL GROWTH STUDIES.

48. Longitudinal growth studies
Bolton brush growth study
Burlington growth study
Michigan growth study
Denver child growth study
Iowa child welfare study
Forsyth twin study
Meharry growth study

49. Montreal growth study
Krogman philadelphia growth study
Fels growth study
Implant studies
The mathews implant collection
The hixon oregon implant study
Cleft palate study

50. Bolton Brush growth study.
Prof T Wingate Todd
skeletal development .
Dr Holly Broadbent Sr
development of facial skeleton.
5000 normal healthy children.
Records

51. Bolton Brush Growth Study
merged in 1970.
published - Dr Holly Broadbent jr.
standards of averages that represent optimum facial and developmental growth baseline for understanding and assessing craniofacial growth.

52. Burlington growth study
AIM
Malocclusion
preventive and interceptive orthodontic treatment.
growth records as a database for future studies.
Sample size:1632 .

53. BURLIGTON GROWTH
STUDY
Records
original concept - Robert Moyers
records-Frank Popovich.

54. Burlington growth study
247 investigations & 322 studies - based on this growth study
Longitudinal studies by Thompson & Popovich to derive cephalometric norms of a representative sample was based on 210 children followed for 15 years at the Burlington growth center.
age sex and growth type specific craniofacial templates were derived and static and dynamic analysis were proposed on the basis of this study.

55. The Iowa child welfare study.
Sample size: 20 males and 15 female 4 year old subjects.
Followed till 17 years of age. Non –orthodontical-European
Records:lateral and PA views and dental casts.
Samir Bishara.

56. changes in facial dimensions ,standing height
The dentofacial relationships of 3 normal facial types (long, average, short) from yrs of age was described & compared.

57. CLEFT PALATE STUDIES.
LANCASTER PA: 850 record sets - birth to 15 years/annually
HOSPITAL FOR SICK CHILDREN(Toronto):over years
.CENTER FOR CRANIOFACIAL ANOMALIES(Chicago); 1000 subjects.
Records: x-ray films, casts, medical and orthodontic treatment records.
All subjects: surgical repair, minor - extensive ortho treatment.

58. METHODS OF
STUDYING GROWTH

59. Ancient Greek Studies On Growth -- According to “Galen et al”.
-- Pattern – Intelligence /
Specific areas of Skull – Specific
Growth
Perfection / Dumbness etc.....

60. -- Constellations, Sun, Moon etc... determine the growth of the body.
Greek Mythology on
Growth Studies
-- Constellations, Sun, Moon etc... determine the growth of the body.

62. Methods of studying Growth

63. CRANIOMETRY. measurements of skull
Neanderthal and Cro-magnon skull.
information of extinct population ,growth pattern
Advantages: Precise measurements.
Disadvantages:All growth data must be cross sectional.

64. ANTHROPOMETRY:
soft tissue pts over bony landmarks- living individuals.
variation in soft tissue thickness - different rslts
individual growth directly measured

65. CEPHALOMETRIC RADIOGRAPHY:
direct measurement - bony skeletal dimensions follow up same individual over time .
Disadvgs
precise orientation of head ,precise control of magnification.
2D of 3D structure

66. Mineralized sections.
less processing distortions , both organic and inorganic matrix- studied simultaneously.
Cellular details , resolutions - enhanced –reduce thickness of the sections.
Special stains
Thin sections- quench- rapidly

67. Microradiography. High resolution of images of bone sections
Differential density btwn pri and seco bone.
Bone strength -proportional to degree of mineralisation.
seco bone more strength than pri bone.
Seco mineralisation process- 8 months to form minimum retention : months.

68. THERMOGRAPHY

69. Scintigraphy
“Hot Spots”.

70. M R I
Magnetic Resonance Imaging
Depicts- soft tissue growth
contrast with hard tissue.

71. Fluorescent labels. in vivo calcium binding labels
anabolic time markers of bone formation.
Mechanism of bone growth determined by analysis of label incidence and interlabel distance.
Sequential use of different colored labels assess bone growth,healing and functional adaptation.
Tetracycline,calcein green,xylenol orange,alizarin complexone,demeclocycline and oxytetracycline

72. Radioisotopes.
Radioisotopes of certain elements or compounds are often used as in vivo markers
labeled material injected and located within the growing bone by autoradiographic techniques.
Technetium 99
Calcium 45
Potassium 32

73. RADIOISOTOPES

74. Autoradiography.
Histological sections are coated with a nuclear track emulsion to detect radiographic precursor for structural and metabolic material.
Specific radioactive labels for protein carbohydrates or nucleic acids are injected.

75. Quantitative and qualitative assessment of the label uptake is a physiologic index of cell activity.
Commonly used autoradiographic labels are:
A H thymidine.
B H proline.
C. Bromodeoxyuridine.

76. Polarized light.
indicates the orientation of collagen fibers within the bone matrix.
Most lamellar bone consists of collagen fibers oriented at right angles.
However 2 other configurations can also be noted:longitudinally aligned(L osteons).

77. And mixed fiber pattern.
Loading condition at the time of bone formation dictate the orientation of collagen fibers . Thus bone formation can adapt to different loading conditions by changing the internal lamellar organization of bone tissue.

78. Nuclear volume morphometry.
cytomorphometric procedure to measures the nuclear size for assessing the stages of differentiation of osteoblastic precursor cells.
Pre osteoblasts have significantly larger nuclei than their precursors.
used in determining the relative differentiation of PDL and other bone living cells.

79. Teleradiology. Introduced in 1982 at international conference of PACS.
Universal method of storing and transporting digital images .
Currently American college of radiology have developed DICOM to allow the transmisssion of images over the internet.

80. Vital staining reported by Belchier in 1796 John Hunter- alizarin dye
Other dyes : tetracyline
trypon blue
lead acetate
procion

81. Vital staining aids in studying:
Manner in which bone is laid down
site of bone growth
the direction and amount of growth
and the timing and relative duration of growth at different sites.

82. Natural markers. developmental features - serial radiography.
trabaculae,nutrient canals, lines of arrested growth
cephalometric landmarks.

83. Implant markers.
Bjork- tantalum or biologically inert alloys into growing bone –
radiographic reference markers for serial cephalometric study.
The method allows precise orientation of serial cephalograms and information on the amount and sites of bone growth.

84. B O N E :- L : ost Gr : osteon
Definition : Modified connective tissue.
Elements comprising bone tissue.
Cells of Bone –
1. osteoprogenitor
2. osteoblast
3. osteocytes
4. osteoclasts
5. bone lining cells

85. Osteoprogenitor Cells
-- Stem cells of mesenchymal origin.
Osteoblast cells
-- Bone forming cells.
-- varied shape
- oval
- triangular
- cuboidal
-- increased RER, golgi apparatus
-- Lay down organic matrix and calcification.

86. Osteocytes Osteoclasts -- imprisoned osteoblast
--keep intact lacunae & canaliculli
-- keep open channel for diffusion
-- removal or deposition of matrix and calcium when reqd.
Osteoclasts
-- Bone removing cells
-- resorption bay or Howship’s lacunae um
-- nuclei-20 or more
-- acid phosphatase and lizosomes

87. Bone Lining Cells Periosteum -- outer layer-fibrous
-- present on ndosteal and periosteal layer
-- can form bone when called for
-- dual function - resorption and deposition.
Periosteum
-- outer layer-fibrous
-- inner layer-cellular
Function– nutritive
-- supportive-sharpey’s fibers
-- reparative-protective-osteoprogenitor cells
-- protective-limiting membrane
-oldage exostosis due to
tear of periosteum

89. Ossification → Intramembraneous↓
endochondral
Intramembranous Ossification

91. Endochondral ossification

93. Comparison of physiologic properties of bone and cartilage
Characteristic cartilage bone
Calcification Non calcified Calcified
Vascularity Avascular Vascular
Surface membrane Nonessential Essential
Pressure resistance Tolerant Sensitive
Rigidity Flexible Inflexible
Modes of growth Interstitial Appositional
and appositional

94. TYPE OF BONES Lamellar bone Non lamellar bone Fine cancellous bone
Coarse cancellous bone
Woven bone
Bundle bone
Composite bone

95. Clinical significance
Full strength of lamellar bone supporting an orthodontically moved tooth is not attained for upto a year after completion of active treatment.

96. Non Lamellar bone Makes up fine cancellous bone tissue
No distinct stratification in fibre orientation

97. Woven bone Type of non lamellar bone
Weak , disorganised, poorly mineralised
Not found in adult human skeleton under normal conditions
First bone formed in response to orthodontic loading.

98. Bundle bone Present adjacent to periodontal ligament
Presence of perpendicular striations called sharpey’s fibres.
Formed on depository side of socket, laid dowm in the direction toward the moving tooth root.

99. Composite bone Predominant bone type during early retention phase
Most rapid means of producing strong bone
Formed by deposition of lamellar bone within a woven bone lattice.

100. Fine cancellous bone tissue
Formed by periosteum and endosteum
Marrow spaces are fine
It is located in cortex e.g. posterior border of a growing ramus in a child
Fastest growing of all bone types

101. Coarse cancellous bone
Produced by endosteum only
Irregular marrow spaces containing red or yellow marrow
Irregularly arranged trabeculae
Present in medulla

102. Mechanisms of bone growth
Deposition and resorption
Growth fields
Modelling
Remodelling
Growth movements
drift
displacement

103. Deposition and resorption
Bone sides which face the direction of growth are subject to deposition (+) and those opposite to it undergo
resorption(-)
…surface principal

104. Deposition and resorption
Bone produced by covering membrane-periosteal bone comprises about half of the cortical bone tissue: bone laid down by the lining membrane-endosteal bone makes up the other half.

105. Transverse histologic section of bone:
A.Periosteal surface reorptive,endosteal surface depository.
B.New endosteal bone addedon inner surface.
C.Endosteal layer produced covered by periosteal layer following outward reversal.
D.Cortex made entirely of periosteal bone….outer surface depository and inner surface resorptive.

106. Growth fields
Inside and outside of every bone is covered by growth fields which control the bone growth.
They are both resorptive and depository types..

107. Provides two growth functions: Enlargement of any given bone
About one half of the bone is periosteal and the other half endosteal.If endosteal surface is resorptive then periosteal surface would be depository.
Provides two growth functions:
Enlargement of any given bone
Remodelling of any given bone

108. Growth sites
Growth fields having special role in the growth of the particular bone are called growth sites
e.g. mandibular condyle, maxillary tuberosity, synchondrosis of the basicranium, sutures and the alveolar process.

109. Growth sites
Such special sites do not out the entire carry growth process but the entire bone takes part

110. Growth centers
Special areas which are believed to control the overall growth of the bone e.g.mandibular condyle.
Force, energy or motor for a bone resides primarily within its growth centre.
Now believed that these centers do not control the whole growth process.

111. MODELING
Bone modeling involves independent sites of resorption and formation that change the size and shape of a bone.

112. CONTROL FACTORS FOR BONE MODELING
Mechanical Peak load in Micro strain.
Disuse atrophy <200.
Bone Maintenance —2500.
Physiological Hypertrophy —4000.
Pathological Overload >4000.

113. Endocrine. Bone metabolic hormones-PTH,Vit D,Calcitonin.
Growth Hormones-Somatotropin,IGF 1,IGF 2.
Sex steroids-Testosterone,Estrogen.

114. Remodelling
Required differential growth activity required for bone shaping.
It involves deposition and resorption occuring on opposite ends
Four types
Biochemical remodelling
Haversian remodelling
Pathologic remodelling
Growth remodelling

115. E.g. The ramus moves posteriorly by the combination of deposition and resorption.
so the anterior part of the ramus gets remodeled into a new addition for the mandibular corpus.

116. Functions of Remodeling
Progressively change the size of whole bone
Sequentially relocate each component of the whole bone
Progressively change the shape of the bone to accommodate its various functions

117. Functions of Remodeling
Progressively change the size of whole bone
Sequentially relocate each component of the whole bone
Progressively change the shape of the bone to accommodate its various functions

118. 4. Progressive fine tune fitting of all the separate bones to each other and to their contiguous ,growing, functioning soft tissues
5. Carry out continuous structural adjustments to adapt to the intrinsic and extrinsic changes in conditions .

119. Drift
It is remodeling process and a combination of deposition and resorption.
If an implant is placed on depository side it gets embedded.eventually marker becomes translocated from one side of cortex to other.

120. Displacement
Displacement is a physical movement of the whole bone as it remodels
Two types:
primary displacement
secondary displacement

121. Primary displacement
It is a physical movement of a whole bone and occurs while the bone grows and remodels by resorption deposition
E.g. in maxilla

122. Secondary displacement
It is the movement of a whole bone caused by the separate enlargement of other bones

123. Combination of remodeling & displacement
Both these mechanisms carries out two general functions
Positions each bone
Designs and constructs each bone

124. Balloon Anology

125. Hand Anology

126. Tripod Chair Anology

127. Rotation
According to Enlow, growth rotation is due to diagonally placed areas of deposition and resorption
Two types
Remodelling rotations
Displacement rotations

128. Principle of ‘Area relocation’
Both remodeling and displacement together
cause a shift in existing
position of a particular
structures with reference to
another .

129. Growth equivalent principle
This principle proposed by Hunter & Enlow
relates the effects of cranial base growth on
the facial bone Growth.

131. Counter Part Principle
Donald H Enlow

132. Regional Change (Stage 1)
Two reference line
Horiz
Verti
P T M

133. Stage 2
°Displacement.
°Amt of forward displacement equals the amt of post length.
°PTM returns to same line.
°Class 2 position of maxilla.

134. Stage 3 What are counterparts of maxillary arch. - NMC - ACF - Palate
- Corpus of
mandible.
mandible described.
- Corpus
- Ramus
Why separate bcoz has separate counterparts.

135. Bony mandi arch cp of max arch.
Body of max arch cp of max arch.
Corpus remodels, what was ramus at once becomes body.
however still cl 2.

136. Stage 4 remodelling and disp of mandi.
condyle and post part of ramus remodels.
process not to increase width of ramus.
but to relocate it postly for lengthening the corpus.

137. stage 5 whole mandible displaced ant by amt ramus has relocated.
post- primary displ.
ramus lengthening remains same.
only corpus horizontal dimension change.
cl 1 returned.
separation of occlusion.

138. stage 6 dimension of temporal lobe and MCF.
Spheno-occipital synchondroses- maj growth site.

139. stage 7 vertical line moves ant. forehead cheekbone ACF Palate
Max arch
all move in ant direction.

140. stage 8 Effect of MCf on mandi.- secondry disp. less than max effect.
bcoz MCF grows in front and between the condyle and maxi tuberosity.
SOS lies between condyle and ant boundary of MCF.

141. stage 9 MCF counterpart ? ramus and pharyngeal space.
skeletol function of ramus
- bridge pharyngeal space and span of MCF.
A-P breadth of ramus is critical.
- too → narrow- retrusive.
→ wide- protrusive.

142. stage 9
floor of ACF & forehead grow by endocranial depostition & ectocranial resorption.
nasal bone – ant displaced.
enlarging bone displaces calvaria – by sutural growth.
depositing new bone at contact edges.
1. frontal.
2. parietal.
3. occipital.
4. temporal.

143. stage 10 NMC – vertical lengthening. remodelling → depo and reso.
prim disp.
resorption of superior (nasal side).
deposition of inferior (oral side).

144. stage 11 Downward mvmt of palate & max arch.
2-3 → downward pri disp & suture grow
1-2 → remodelling.
2-3 → downward disp.
1-2 → teeth own mvmnt ( vertical drift).
can be clinically influenced by appliances.

145. Stage 12 upward / superior drift of each mandi tooth.
max teeth drift more than mandi teeth.
less growth “to work with” in mandi.
curve of spee.

146. stage 13 remodelling also - incisor alveolar region. - chin.
- corpus of mandi.
differential growth timing.

147. stage 14 rationale of growth of zygo process.
zygo remodels → post more deposition
→ ant less resorption
hence forward growth.

148. Enlow’s V principal
Most useful and basic concept in facial growth as many facial and cranial bones have a V- shaped configuration.
Bone deposition(+) occurs on the inner side and resorption (-) occurs on the outer surface.

149. Example with V oriented vertically
When bone added on lingual side of coronoid process,growth proceeds and this part of the ramus increases in vertical dimension.

150. Example of V oriented horizontally
Same deposits of bone also bring about a posterior direction of growth movement.
This produces a backward movement of coronoid processes even though deposit is on the lingual side.

152. Same deposits carry base of bone in medial direction as in fig 1.
Hence, the wider part undergoes relocation into a more narrow part as the whole v moves towards the wide part (fig 2)

153. REFERENCES: Proffit:contemporary orthodontics.
Moyers:handbook of orthodontics.
An inventory of United states and Canadian growth record sets.S.Hunter , Baumrind S AJO 1993.
Craniofacial imaging in orthodontics :S Kapila et al AO 1999:69
Essays in honour of Robert moyers CFGS.monograph 24.

154. References Bone biodynamics in orthodontics:CFGS.27
Atlas of craniofacial growth in Americans of African descent CFGS.26
Growth changes in the nasal profile from 7-8 yrs AJO 1988:94 Meng H ,R Nanda
Longitudinal changes in 3 normal facial types .S Bishara,AJO1985:88
S Bishara,J R Peterson, changes in the facial dimensions & relationships between the ages 5-25yrs.AJO 1984:85

155. References
Lewis A B, Roche AF pubertal spurts in cranial base & mandible AJO 1985:55
Popovich.Thompson. Craniofacial templates for orthodontic case analysis.
Baumrind S,Korn EL,quantitation of maxillary remodeling. AJO 1987:91
Atlas of craniofacial growth CFGS monograph 2.
Moyers,Van Der Linden standards of human occlusal development CFGS:5
B Grayson 3D cephalogram theory,technique and clinical application.