1
GROWTH & DEVELOPMENT
DEFINITIONS AND
TERMINOLOGIES
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.india...
2
Definition of Growth
 ―Growth refers to increase in size‖ - Todd
 ―Growth usually refers to an increase in size
and nu...
3
 ―Growth may be defined as the normal
change in the amount of living substance
 ―Change in any morphological parameter...
4
Definition of Development
Development is a progress towards
maturity” – Todd
“Development connotes a maturational
proces...
5
“Development refers to all
naturally occurring
progressive, unidirectional, sequen
tial changes in the life of an
indivi...
6
Definitions
Morphogenesis – ―A biologic
process having an underlying control at
the cellular and tissue levels‖
Differ...
7
•Translocation –
― It is a change in position‖
•Maturation –
―It is the emergence of personal
characteristics and behavi...
8
DIFFERENT KINDS OF
GROWTH
 Size change
 Positional change
 Proportional
change
Functional change
Maturational chang...
9
Timing and sequential change
a. Prenatal growth
b. Postnatal growth
c. Maturity
d .Old age
www.indiandentalacademy.com
10
Size change- height, weight, girth ,
volume
Positional change-
•Migration of neural crest cells
•Eruption of teeth
•Dro...
11
Proportional change
Eg-Head of the infant
Functional change
Eg-Secretion , production of enzymes,
hormones
www.indiande...
12
Maturational change
-Towards a period of stability and
adulthood
Compositional change
Eg-Eye pigmentation
www.indianden...
13
Timing and sequential change
•Prenatal growth- rapid increase in cell no.
•Postnatal growth- 20 yrs- declining growth-
...
14
Major themes of
development
 Changing complexity
 Shifts from competent to fixation
 Shifts from dependent to indepe...
15
Changing complexity
 All level of organisation sub-cellular
to the whole organism
 Complexity development
 Orthodont...
16
Shifts from competent to fixation
 Undifferentiated cells once differentiated
become fixed.
Shifts from dependent to
i...
17
Ubiquity of genetic control
modulated by environment
 Genetic control of development is
constantly being modified by
e...
18
Correlation between
Growth & Development
 Growth anatomic phenomenon
quantitative
Development physiologic
phenomenon q...
19
Growth
•Increase in size decrease in
size
eg- thymus gland after puberty
Development process of increasing
complexity.
...
20
Importance of growth and
development to orthodontist
 To understand the etiology of malocclusion
 To assess the healt...
21
 To identify abnormal occlusal
development at an earlier stage
 use of growth spurts
 Surgery initiation
 Planning ...
22
Normal features of
Growth & Development
 pattern
-Differential Growth
-cephalocaudal gradient of growth
 Variability
...
23
PATTERN
 Pattern in growth represents proportionality .It
refers not just to a set of proportional
relationships at a ...
24
DIFFERENTIAL GROWTH
Different organs grow at different
rates to a different amount and at
different times.
 Scammon‘s ...
25
SCAMMON‘S CURVE OF
GROWTH
 LYMPHOID
 NEURAL
 GENERAL
 GENITAL
www.indiandentalacademy.com
26
CEPHALOCAUDAL GRADIENT
OF GROWTH
• Changes which are a part of normal
growth pattern reflect ―Cephalocaudal
gradient of...
27
CEPHALOCAUDAL GRADIENT
OF GROWTH
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28
Growth of head and face
www.indiandentalacademy.com
29
•It illustrates the change in overall body
proportions during normal growth and
development.
•Imp aspect of pattern is ...
30
Predictability
 Predictability of growth pattern is a specific
kind of proportionality that exists at a
particular tim...
31
Variability
 No two individuals with the exception of
siamese twins are like.
 Hence it is important to have a ―norma...
32
Normality
 Normality refers to that which is usually
expected, is ordinarily seen or typical – Moyers
 Normality may ...
33
Growth chart
www.indiandentalacademy.com
34
Applications of growth charts.
 Location of an individual relative to the
group can be established.
 Can be used to f...
35
Timing of Growth
 One of the factors for variablity in growth.
 Timing variations arise because biologic clock
of dif...
36
Distance curve
Vs
Velocity curve
Distance curve
Velocity curveAge
Height
Distance Curve (cumulative curve): In this cur...
37
Growth spurts
 Defined as periods of growth acceleration
 Sex-linked
 Normal spurts are
 Infantile spurt – at 3 yea...
38www.indiandentalacademy.com
39www.indiandentalacademy.com
40
GROWTH STUDIES AND METHODS
OF STUDYING GROWTH.
www.indiandentalacademy.com
41
• Types of growth data
• Methods of gathering growth data
• Longitudinal growth studies
• Methods of studying bone grow...
42
Types of growth data.
Opinion
Observations.
Ratings and
rankings.
Quantitative
measurements.
direct data.
indirect ...
43
Types of growth data.
• Opinion
It is a clever guess based on experience.
they are the crudest form of scientific
knowl...
44
• Ratings and rankings:
certain data is difficult to quantify and thus
may be compared to conventional rating
scale .ra...
45
Quantitative measurements:
Includes expressing an idea or fact as a
meaningful quantity or numbers.
• Direct data: deri...
46
Methods of gathering growth
data.
• Longitudinal studies .
• Cross sectional studies.
• Overlapping or semi longitudina...
47
Longitudinal studies.
• These are measurements made of the same
person or group at regular intervals through
time.
• Ad...
48
Cross sectional studies
ADVANTAGES
 Quicker
 Less costly
 Statistical treatment made easier
 Allows repeating
DISAD...
49
Semi longitudinal studies.
• Longitudinal and cross sectional studies can
be combined to to seek the advantages of
both...
50
LONGITUDINAL GROWTH
STUDIES.
www.indiandentalacademy.com
51
Longitudinal growth studies
 Bolton brush growth study
 Burlington growth study
 Michigan growth study
 Denver chil...
52
 Montreal growth study
 Krogman philadelphia growth study
 Fels growth study
 Implant studies
 the mathews implant...
53
Bolton Brush growth study.
• Initiated by Prof T Wingate Todd in 1926
• Aim- studying skeletal development .
• Initiate...
54
• The two collections merged officially in 1970.
• In 1975 the Bolton standards of dentofacial development
growth were ...
55
Burlington growth study
• AIM
• Malcclusion
• Evaluate preventive and interceptive orthodontic
treatment.
• Obtain a se...
56
 Records :series of x-
rays, casts,photographs,height and
weight records and medical
examination.
 The original conce...
57
Burlington growth study
• More than 247 investigations & 322 studies are
based on this growth study
• Longitudinal stud...
58
The Iowa child welfare study.
• Sample size:it is a diminishing longitudinal
study which began with 20 males and 15
fem...
59
• Based on this study the changes in facial
dimensions & relationships as well as in
standing height were evaluated.
• ...
60
CLEFT PALATE STUDIES.
• LANCASTER PA:includes 850 record sets obtained
annually from birth to 15 years.
• HOSPITAL FOR ...
61
Methods of studying bone growth
cephalometry.
anthropometry.
craniometry.
measurement approaches.
autoradiography.
nucl...
62
CRANIOMETRY.
Involves measurements of skull
used to study the Neanderthal
and Cro-magnon skull.
give information of ext...
63
ANTHROPOMETRY:
• measurements using soft tissue points overlying
bony landmarks in living individuals.
• can also be do...
64
• CEPHALOMETRIC RADIOGRAPHY:
• allows direct measurement of bony skeletal
dimensions and follow up of the same individu...
65
Mineralized sections.
• Fully mineralized sections are superior to
demineralized specimens as there is less processing
...
66
Microradiography.
• High resolution of images of bone sections
• Differential density between primary and
secondary bon...
67
Fluorescent labels.
• Administered in vivo calcium binding labels
• anabolic time markers of bone formation.
• Mechanis...
68
Radioisotopes.
• Radioisotopes of certain elements or compounds
are often used as in vivo markers for studying
bone gro...
69
Autoradiography.
• Histological sections are coated with a nuclear track
emulsion to detect radiographic precursor for
...
70
• Quantitative and qualitative assessment of the label uptake
is a physiologic index of cell activity.
• Commonly used ...
71
Polarized light.
• indicates the orientation of collagen fibers within
the bone matrix.
• Most lamellar bone consists o...
72
• And mixed fiber pattern.(both L and A osteons).
• Loading condition at the time of bone formation
dictate the orienta...
73
Nuclear volume morphometry.
• cytomorphometric procedure to measures the
nuclear size for assessing the stages of
diffe...
74
Teleradiology.
 Introduced in 1982 at international
conference of PACS.
 Universal method of storing and
transporting...
75
Vital staining
• reported by Belchier in 1796
• John Hunter- alizarin dye
• Alizarin reacts with calcium at sites of bo...
76
• Vital staining aids in studying:
Manner in which bone is laid down
site of bone growth
the direction and amount of gr...
77
Natural markers.
• The persistence of certain developmental features
has led to their use as natural markers by means o...
78
Implant markers.
• Bjork devised a method of implanting tiny bits of
tantalum or biologically inert alloys into growing...
79
Mechanism of growth
 3 mechanisms at the cellular level
 Hyperplasia
 Hypertrophy
 Secretion of extracellular matte...
80
Mechanism of growth in
soft tissues
 In soft tissues growth occurs by a combination of two
mechanisms namely:
 hyperp...
81
Mechanism of growth in hard
tissues.
 The craniofascial skeleton grows by three
unique processes:
 Chondrogenesis: fo...
82
Comparison of physiologic
properties of bone and cartilage
 Characteristic cartilage bone
 Calcification Non calcifie...
83
Endochondral bone formation
 Definition:It is the process of converting
cartilage into bone.
 Occurs in regions expos...
84
Steps of chondrogenesis
 Chodroblasts produce matrix
 Cells become encased in matrix
 Chondrocytes enlarge,divide an...
85
Steps of endochondral bone
formation
 hypertrophy of chondrocytes and matrix
calcifies
 Invasion of blood vessels and...
86
Intramembranous bone
formation
Definition: it is the process of bone formation
from undifferentiated mesenchymal tissue...
87
–Seen in areas like:
– Cranial vault
• Maxilla
• Mandible except condylar
cartilage
www.indiandentalacademy.com
88
Steps of intramembranous bone
formation
 Osteoblasts produce osteoid tissue.
 Cells and blood vessels are encased.
 ...
89
Bone metabolism
• Bone is the primary calcium reservoir of the body
(99% stored in skeleton)
•Bone structure is sacrifi...
90
Bone metabolism
Calcium homeostasis is supported by 3 mechanisms :
1. Rapid instantaneous flux of calcium from boneflui...
91
TYPE OF BONES
 Lamellar bone
 Non lamellar bone
 Fine cancellous bone
 Coarse cancellous bone
 Woven bone
 Bundle...
92
LAMELLAR BONE
 Comprises 99% of human skeleton
 Strong highly mineralised
 Mineralised in two stages:
 primary mine...
93
Clinical significance
 Full strength of lamellar bone supporting
an orthodontically moved tooth is not
attained for up...
94
Non Lamellar bone
 Makes up fine cancellous bone tissue
 No distinct stratification in fibre
orientation
www.indiande...
95
Woven bone
 Type of non lamellar bone
 Weak , disorganised, poorly mineralised
 Not found in adult human skeleton
un...
96
Bundle bone
 Present adjacent to periodontal
ligament
 Presence of perpendicular striations
called sharpey‘s fibres.
...
97
Composite bone
 Predominant bone type during early
retention phase
 Most rapid means of producing strong
bone
 Forme...
98
Fine cancellous bone tissue
 Formed by periosteum and endosteum
 Marrow spaces are fine
 It is located in cortex e.g...
99
Coarse cancellous bone
 Produced by endosteum only
 Irregular marrow spaces containing red
or yellow marrow
 Irregul...
100
Mechanisms of bone growth
 Deposition and resorption
 Growth fields
 Modelling
 Remodelling
 Growth movements
dri...
101
Deposition and resorption
 Bone sides which face
the direction of growth
are subject to
deposition (+) and
those oppo...
102
Deposition and resorption
 Bone produced by
covering membrane-
periosteal bone
comprises about half
of the cortical b...
103
Enlow‘s V principal
 Most useful and basic
concept in facial
growth as many facial
and cranial bones have
a V- shaped...
104
Transverse histologic section of bone:
A.Periosteal surface reorptive,endosteal
surface depository.
B.New endosteal bo...
105
Example with V oriented vertically
 When bone added
on lingual side of
coronoid
process,growth
proceeds and this
part...
106
Example of V oriented horizontally
 Same deposits of
bone also bring
about a posterior
direction of growth
movement.
...
107www.indiandentalacademy.com
108
 Same deposits carry
base of bone in medial
direction as in fig 1.
 Hence, the wider part
undergoes relocation
into ...
109
Growth fields
 Inside and outside of
every bone is
covered by growth
fields which control
the bone growth.
 They are...
110
 About one half of the
bone is periosteal and
the other half
endosteal.If endosteal
surface is resorptive
then perios...
111
Growth sites
 Growth fields having
special role in the
growth of the particular
bone are called growth
sites
 e.g. m...
112
Growth sites
 Such special
sites do not out
the entire carry
growth process
but the entire
bone takes part
www.indian...
113
Growth centers
 Special areas which are
believed to control the
overall growth of the
bone e.g.mandibular
condyle.
 ...
114
MODELING
 Bone modeling involves
independent sites of resorption
and formation that change the
size and shape of a bo...
115
CONTROL FACTORS FOR
BONE MODELING
– Mechanical Peak
load in Micro strain.
1. Disuse atrophy <200.
2. Bone Maintenance ...
116
• Endocrine.
1. Bone metabolic hormones-PTH,Vit D,Calcitonin.
2. Growth Hormones-Somatotropin,IGF 1,IGF 2.
3. Sex ster...
117
Remodelling
 Required differential growth activity required for bone
shaping.
 It involves deposition and resorption...
118
 E.g. The ramus moves
posteriorly by the
combination of
deposition and
resorption.
 so the anterior part of
the ramu...
119
Functions of Remodeling
1. Progressively change the size of whole bone
2. Sequentially relocate each component of the
...
120
1. Progressively change
the size of whole bone
2. Sequentially relocate
each component of
the whole bone
3. Progressiv...
121
4. Progressive fine tune fitting of all the
separate bones to each other and to their
contiguous ,growing, functioning...
122
Drift
 It is remodeling process
and a combination of
deposition and
resorption.
 If an implant is placed
on deposito...
123
Displacement
 Displacement is a physical movement of
the whole bone as it remodels
 Two types:
primary displacement
...
124
Primary displacement
 It is a physical
movement of a
whole bone and
occurs while the
bone grows and
remodels by
resor...
125
Secondary displacement
 It is the movement
of a whole bone
caused by the
separate
enlargement of
other bones
www.indi...
126
Combination of remodeling &
displacement
 Both these mechanisms carries out two
general functions
 Positions each bo...
127
Rotation
 According to
Enlow, growth rotation
is due to diagonally
placed areas of
deposition and
resorption
 Two ty...
128
Principle of ‗Area relocation‘
Both remodeling and
displacement together
cause a shift in existing
position of a parti...
129
Counter part principle
 ―Growth of any given
facial or cranial part
relates specifically to
other structural and
geom...
130
Growth equivalent principle
This principle proposed by Hunter & Enlow
relates the effects of cranial base growth on
th...
131www.indiandentalacademy.com
132
REFERENCES:
 Proffit:contemporary orthodontics.
 Moyers:handbook of orthodontics.
 An inventory of United states an...
133
References
 Bone biodynamics in orthodontics:CFGS.27
 Atlas of craniofacial growth in Americans of
African descent C...
134
References
 Lewis A B, Roche AF pubertal spurts in
cranial base & mandible AJO 1985:55
 Popovich.Thompson. Craniofac...
www.indiandentalacademy.com 135
Thank you
For more details please visit
www.indiandentalacademy.com
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Growth and development (2)/certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.


Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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Growth and development (2)/certified fixed orthodontic courses by Indian dental academy

  1. 1. 1 GROWTH & DEVELOPMENT DEFINITIONS AND TERMINOLOGIES INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. 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. www.indiandentalacademy.com
  3. 3. 3  ―Growth may be defined as the normal change in the amount of living substance  ―Change in any morphological parameter which is measurable‖- Moss.  ―Size development , progressive development (i.e, evolution, emergence, increase or expansion)‖- Webster’s dictionary. www.indiandentalacademy.com
  4. 4. 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 www.indiandentalacademy.com
  5. 5. 5 “Development refers to all naturally occurring progressive, unidirectional, sequen tial 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 www.indiandentalacademy.com
  6. 6. 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‖ www.indiandentalacademy.com
  7. 7. 7 •Translocation – ― It is a change in position‖ •Maturation – ―It is the emergence of personal characteristics and behavioural phenomenon through growth processes‖ www.indiandentalacademy.com
  8. 8. 8 DIFFERENT KINDS OF GROWTH  Size change  Positional change  Proportional change Functional change Maturational change Compositional change www.indiandentalacademy.com
  9. 9. 9 Timing and sequential change a. Prenatal growth b. Postnatal growth c. Maturity d .Old age www.indiandentalacademy.com
  10. 10. 10 Size change- height, weight, girth , volume Positional change- •Migration of neural crest cells •Eruption of teeth •Dropping of diaphragm from 4th cervical vertebra to the level of 12th thaoracic vertebra www.indiandentalacademy.com
  11. 11. 11 Proportional change Eg-Head of the infant Functional change Eg-Secretion , production of enzymes, hormones www.indiandentalacademy.com
  12. 12. 12 Maturational change -Towards a period of stability and adulthood Compositional change Eg-Eye pigmentation www.indiandentalacademy.com
  13. 13. 13 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 www.indiandentalacademy.com
  14. 14. 14 Major themes of development  Changing complexity  Shifts from competent to fixation  Shifts from dependent to independent  Ubiquity of genetic control modulated by environment www.indiandentalacademy.com
  15. 15. 15 Changing complexity  All level of organisation sub-cellular to the whole organism  Complexity development  Orthodontics Mixed dentition period www.indiandentalacademy.com
  16. 16. 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. www.indiandentalacademy.com
  17. 17. 17 Ubiquity of genetic control modulated by environment  Genetic control of development is constantly being modified by environmental interactions www.indiandentalacademy.com
  18. 18. 18 Correlation between Growth & Development  Growth anatomic phenomenon quantitative Development physiologic phenomenon qualitative www.indiandentalacademy.com
  19. 19. 19 Growth •Increase in size decrease in size eg- thymus gland after puberty Development process of increasing complexity. Development=growth+differenciation+translocation www.indiandentalacademy.com
  20. 20. 20 Importance of growth and development to orthodontist  To understand the etiology of malocclusion  To assess the health and nutrition of children  Allows comparison of growth of an individual child with the growth of other children www.indiandentalacademy.com
  21. 21. 21  To identify abnormal occlusal development at an earlier stage  use of growth spurts  Surgery initiation  Planning of retention regime www.indiandentalacademy.com
  22. 22. 22 Normal features of Growth & Development  pattern -Differential Growth -cephalocaudal gradient of growth  Variability  Timing, rate & direction www.indiandentalacademy.com
  23. 23. 23 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. www.indiandentalacademy.com
  24. 24. 24 DIFFERENTIAL GROWTH Different organs grow at different rates to a different amount and at different times.  Scammon‘s curve of growth -Richard scammon www.indiandentalacademy.com
  25. 25. 25 SCAMMON‘S CURVE OF GROWTH  LYMPHOID  NEURAL  GENERAL  GENITAL www.indiandentalacademy.com
  26. 26. 26 CEPHALOCAUDAL GRADIENT OF GROWTH • Changes which are a part of normal growth pattern reflect ―Cephalocaudal gradient of growth‖ • It implies that there is an axis of increased growth extending from the head toward the feet. www.indiandentalacademy.com
  27. 27. 27 CEPHALOCAUDAL GRADIENT OF GROWTH www.indiandentalacademy.com
  28. 28. 28 Growth of head and face www.indiandentalacademy.com
  29. 29. 29 •It illustrates the change in overall body proportions during normal growth and development. •Imp aspect of pattern is its predictability. www.indiandentalacademy.com
  30. 30. 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. www.indiandentalacademy.com
  31. 31. 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 www.indiandentalacademy.com
  32. 32. 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‖ • www.indiandentalacademy.com
  33. 33. 33 Growth chart www.indiandentalacademy.com
  34. 34. 34 Applications of growth charts.  Location of an individual relative to the group can be established.  Can be used to follow a child over time and note for any unexpected change in growth pattern. www.indiandentalacademy.com
  35. 35. 35 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 www.indiandentalacademy.com
  36. 36. 36 Distance curve Vs Velocity curve Distance curve Velocity curveAge Height 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 incrementwww.indiandentalacademy.com
  37. 37. 37 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 – 10-11 years(females); 18-15 years (males)  Growth modulation can be done www.indiandentalacademy.com
  38. 38. 38www.indiandentalacademy.com
  39. 39. 39www.indiandentalacademy.com
  40. 40. 40 GROWTH STUDIES AND METHODS OF STUDYING GROWTH. www.indiandentalacademy.com
  41. 41. 41 • Types of growth data • Methods of gathering growth data • Longitudinal growth studies • Methods of studying bone growth www.indiandentalacademy.com
  42. 42. 42 Types of growth data. Opinion Observations. Ratings and rankings. Quantitative measurements. direct data. indirect data. www.indiandentalacademy.com
  43. 43. 43 Types of growth data. • Opinion It is a clever guess based on experience. they are the crudest form of scientific knowledge. • Observations: They are useful for studying all or none phenomenon.they are used in a limited way when more quantitative data is available. www.indiandentalacademy.com
  44. 44. 44 • Ratings and rankings: certain data is difficult to quantify and thus may be compared to conventional rating scale .ratings make use of comparisons with such scales.rankings array data in ordered sequence according to value. www.indiandentalacademy.com
  45. 45. 45 Quantitative measurements: Includes expressing an idea or fact as a meaningful quantity or numbers. • Direct data: derived from measurements taken on living persons or cadaver with a measuring device. • Indirect data: derived from measurements taken from images or reproductions of the actual person. • Derived data: obtained by comparing at least two other measurements. www.indiandentalacademy.com
  46. 46. 46 Methods of gathering growth data. • Longitudinal studies . • Cross sectional studies. • Overlapping or semi longitudinal studies. www.indiandentalacademy.com
  47. 47. 47 Longitudinal studies. • These are measurements made of the same person or group at regular intervals through time. • Advantages: temporary temporal problems are smoothed with time, Variability in development within a group is put in proper perspective,serial comparison makes study of specific developmental pattern of individual possible. Disadvantages: time consuming, expensive, sample loss orwww.indiandentalacademy.com
  48. 48. 48 Cross sectional studies ADVANTAGES  Quicker  Less costly  Statistical treatment made easier  Allows repeating DISADVANTAGES  Variation in development amongst individuals within the sample cannot be studied www.indiandentalacademy.com
  49. 49. 49 Semi longitudinal studies. • Longitudinal and cross sectional studies can be combined to to seek the advantages of both.in this way one might compress 15 years of study into 3 years of gathering growth data. www.indiandentalacademy.com
  50. 50. 50 LONGITUDINAL GROWTH STUDIES. www.indiandentalacademy.com
  51. 51. 51 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 www.indiandentalacademy.com
  52. 52. 52  Montreal growth study  Krogman philadelphia growth study  Fels growth study  Implant studies  the mathews implant collection  the hixon oregon implant study  Cleft palate study www.indiandentalacademy.com
  53. 53. 53 Bolton Brush growth study. • Initiated by Prof T Wingate Todd in 1926 • Aim- studying skeletal development . • Initiated concurrently by Dr Holly Broadbent Sr in 1929. • Aim- studying normal development of facial skeleton. • Sample size:5000 normal healthy children. • Records:series of x-rays,casts,dental and medical examination and psychological tests. www.indiandentalacademy.com
  54. 54. 54 • The two collections merged officially in 1970. • In 1975 the Bolton standards of dentofacial development growth were published by Dr Holly Broadbent jr. • These standards are a series of averages that represent optimum facial and developmental growth and form a baseline for understanding and assessing craniofacial growth. www.indiandentalacademy.com
  55. 55. 55 Burlington growth study • AIM • Malcclusion • Evaluate preventive and interceptive orthodontic treatment. • Obtain a set of growth records as a database for future studies. • Sample size:1632 subjects followed longitudinally. www.indiandentalacademy.com
  56. 56. 56  Records :series of x- rays, casts,photographs,height and weight records and medical examination.  The original concept for the study was presented by Robert Moyers& the records were gathered under Frank Popovich. www.indiandentalacademy.com
  57. 57. 57 Burlington growth study • More than 247 investigations & 322 studies are 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. www.indiandentalacademy.com
  58. 58. 58 The Iowa child welfare study. • Sample size:it is a diminishing longitudinal study which began with 20 males and 15 female 4 year old subjects. Followed till 17 years of age. Non -orthodontically treated patients of entirely European origin were used. • Records:lateral and PA views and dental casts. • The study as done under Samir Bishara. www.indiandentalacademy.com
  59. 59. 59 • Based on this study the changes in facial dimensions & relationships as well as in standing height were evaluated. • The dentofacial relationships of 3 normal facial types (long, average, short) from 5-25 yrs of age was described & compared. www.indiandentalacademy.com
  60. 60. 60 CLEFT PALATE STUDIES. • LANCASTER PA:includes 850 record sets obtained annually from birth to 15 years. • HOSPITAL FOR SICK CHILDREN(Toronto):over 4000 subjects ranging in age from 5-20 years • .CENTER FOR CRANIOFACIAL ANOMALIES(Chicago);annual records of 1000 subjects. • Records include series of x-ray films, casts, medical and orthodontic treatment records. • All subjects had surgical repair and minor to extensive orthodontic treatment. www.indiandentalacademy.com
  61. 61. 61 Methods of studying bone growth cephalometry. anthropometry. craniometry. measurement approaches. autoradiography. nuclear volume morphometry. radioisotopes. polarised light. fluorescent labels. microradiography. mineralised sections. at microscopic level. finite element modeling. implant markers at macroscopic level. natural markers. comparative anatomy. vital staining. at both levels. experimental approaches. www.indiandentalacademy.com
  62. 62. 62 CRANIOMETRY. Involves measurements of skull used to study the Neanderthal and Cro-magnon skull. give information of extinct population and pattern of growth Advantages: Precise measurements. Disadvantages:All growth data must be cross sectional. www.indiandentalacademy.com
  63. 63. 63 ANTHROPOMETRY: • measurements using soft tissue points overlying bony landmarks in living individuals. • can also be done on dried skulls but variation in soft tissue thickness would produce different results. • Possible to follow the growth of an individual directly. www.indiandentalacademy.com
  64. 64. 64 • CEPHALOMETRIC RADIOGRAPHY: • allows direct measurement of bony skeletal dimensions and follow up of the same individual over time . • Disadvantages •:Depends upon precise orientation of head and precise control of magnification. • 2D representation of 3D structurewww.indiandentalacademy.com
  65. 65. 65 Mineralized sections. • Fully mineralized sections are superior to demineralized specimens as there is less processing distortions and both organic and inorganic matrix can be studied simultaneously. • Cellular details and resolutions can be enhanced by reducing the thickness of the sections. • Specific stains can be used to enhance both cellular and extra cellular details. • Thin sections can however quench more rapidly www.indiandentalacademy.com
  66. 66. 66 Microradiography. • High resolution of images of bone sections • Differential density between primary and secondary bone. • Strength of the bone-proportional to degree of mineralisation. • secondary bone has more strength than primary bone. • Secondary mineralisation process takes about 8 months to form and hence the minimum retention period after active orthodontic correction should be 6-8 months. www.indiandentalacademy.com
  67. 67. 67 Fluorescent labels. • Administered 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 commonly used labels. www.indiandentalacademy.com
  68. 68. 68 Radioisotopes. • Radioisotopes of certain elements or compounds are often used as in vivo markers for studying bone growth. • Such labeled material is injected and after some time located within the growing bone by means of autoradiographic techniques. • Commonly used markers are : 1. Technetium 99 2. Calcium 45 3. Potassium 32 www.indiandentalacademy.com
  69. 69. 69 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. www.indiandentalacademy.com
  70. 70. 70 • Quantitative and qualitative assessment of the label uptake is a physiologic index of cell activity. • Commonly used autoradiographic labels are: • A. 3 H thymidine. • B. 3 H proline. • C. Bromodeoxyuridine. www.indiandentalacademy.com
  71. 71. 71 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). www.indiandentalacademy.com
  72. 72. 72 • And mixed fiber pattern.(both L and A osteons). • 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. www.indiandentalacademy.com
  73. 73. 73 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. www.indiandentalacademy.com
  74. 74. 74 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. www.indiandentalacademy.com
  75. 75. 75 Vital staining • reported by Belchier in 1796 • John Hunter- alizarin dye • Alizarin reacts with calcium at sites of bone calcification i.e. sites of active skeletal growth thus marking these locations • Other dyes : tetracyline trypon blue lead acetate procion www.indiandentalacademy.com
  76. 76. 76 • 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. www.indiandentalacademy.com
  77. 77. 77 Natural markers. • The persistence of certain developmental features has led to their use as natural markers by means of serial radiography. • Eg: trabaculae,nutrient canals and lines of arrested growth can be used for reference to study deposition, resorption and remodeling. • Certain natural markers are used as cephalometric landmarks. www.indiandentalacademy.com
  78. 78. 78 Implant markers. • Bjork devised a method of implanting tiny bits of tantalum or biologically inert alloys into growing bone which served as 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. www.indiandentalacademy.com
  79. 79. 79 Mechanism of growth  3 mechanisms at the cellular level  Hyperplasia  Hypertrophy  Secretion of extracellular matter www.indiandentalacademy.com
  80. 80. 80 Mechanism of growth in soft tissues  In soft tissues growth occurs by a combination of two mechanisms namely:  hyperplasia and hypertrophy  These result in interstitial growth. www.indiandentalacademy.com
  81. 81. 81 Mechanism of growth in hard tissues.  The craniofascial skeleton grows by three unique processes:  Chondrogenesis: formation of cartilage  Endochondral bone formation: process of converting cartilage into bone  Intramembranous bone formation: process of bone formation from undifferentitaed mesenchymal tissue.www.indiandentalacademy.com
  82. 82. 82 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 www.indiandentalacademy.com
  83. 83. 83 Endochondral bone formation  Definition:It is the process of converting cartilage into bone.  Occurs in regions exposed to high levels of compression  In craniofacial region it is seen in areas like  Synchondrosis at the cranial base  Condylar cartilage  Nasal septal cartilage www.indiandentalacademy.com
  84. 84. 84 Steps of chondrogenesis  Chodroblasts produce matrix  Cells become encased in matrix  Chondrocytes enlarge,divide and produce matrix  Matrix remains uncalcified  Membrane covers the surface but is not essential www.indiandentalacademy.com
  85. 85. 85 Steps of endochondral bone formation  hypertrophy of chondrocytes and matrix calcifies  Invasion of blood vessels and connective tissue cells.  osteoblasts differentiate and produce osteoid tissue.  osteoblast tissue calcifies. www.indiandentalacademy.com
  86. 86. 86 Intramembranous bone formation Definition: it is the process of bone formation from undifferentiated mesenchymal tissue  Derived from neural crest cells  Occurs in areas exposed to tension  It differs from endochondral bone formation by formation of bone directly from mesenchymal tissue www.indiandentalacademy.com
  87. 87. 87 –Seen in areas like: – Cranial vault • Maxilla • Mandible except condylar cartilage www.indiandentalacademy.com
  88. 88. 88 Steps of intramembranous bone formation  Osteoblasts produce osteoid tissue.  Cells and blood vessels are encased.  Osteoid tissue is produced by membrane cells.  Osteoid calcifies.  Essential membrane covers bone. www.indiandentalacademy.com
  89. 89. 89 Bone metabolism • Bone is the primary calcium reservoir of the body (99% stored in skeleton) •Bone structure is sacrificed to maintain the critical serum calcium levels at 10mg % www.indiandentalacademy.com
  90. 90. 90 Bone metabolism Calcium homeostasis is supported by 3 mechanisms : 1. Rapid instantaneous flux of calcium from bonefluid (seconds) by selective transfer of calcium ions into and out of bone fluid. 2. Shorterm control of serum calcium levels affects rates of bone formation $ resorption 3. Longterm regulation of metabolism- have effects on skeleton . www.indiandentalacademy.com
  91. 91. 91 TYPE OF BONES  Lamellar bone  Non lamellar bone  Fine cancellous bone  Coarse cancellous bone  Woven bone  Bundle bone  Composite bone www.indiandentalacademy.com
  92. 92. 92 LAMELLAR BONE  Comprises 99% of human skeleton  Strong highly mineralised  Mineralised in two stages:  primary mineralisation  secondary mineralisation www.indiandentalacademy.com
  93. 93. 93 Clinical significance  Full strength of lamellar bone supporting an orthodontically moved tooth is not attained for upto a year after completion of active treatment. www.indiandentalacademy.com
  94. 94. 94 Non Lamellar bone  Makes up fine cancellous bone tissue  No distinct stratification in fibre orientation www.indiandentalacademy.com
  95. 95. 95 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. www.indiandentalacademy.com
  96. 96. 96 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. www.indiandentalacademy.com
  97. 97. 97 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. www.indiandentalacademy.com
  98. 98. 98 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 www.indiandentalacademy.com
  99. 99. 99 Coarse cancellous bone  Produced by endosteum only  Irregular marrow spaces containing red or yellow marrow  Irregularly arranged trabeculae  Present in medulla www.indiandentalacademy.com
  100. 100. 100 Mechanisms of bone growth  Deposition and resorption  Growth fields  Modelling  Remodelling  Growth movements drift displacement www.indiandentalacademy.com
  101. 101. 101 Deposition and resorption  Bone sides which face the direction of growth are subject to deposition (+) and those opposite to it undergo resorption(-) …surface principal www.indiandentalacademy.com
  102. 102. 102 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. www.indiandentalacademy.com
  103. 103. 103 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. www.indiandentalacademy.com
  104. 104. 104 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. www.indiandentalacademy.com
  105. 105. 105 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. www.indiandentalacademy.com
  106. 106. 106 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. www.indiandentalacademy.com
  107. 107. 107www.indiandentalacademy.com
  108. 108. 108  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) www.indiandentalacademy.com
  109. 109. 109 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.. www.indiandentalacademy.com
  110. 110. 110  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 www.indiandentalacademy.com
  111. 111. 111 Growth sites  Growth fields having special role in the growth of the particular bone are called growth sites  e.g. mandibular condyle, maxillary tuberosity, synchondros is of the basicranium, sutures and the alveolar process. www.indiandentalacademy.com
  112. 112. 112 Growth sites  Such special sites do not out the entire carry growth process but the entire bone takes part www.indiandentalacademy.com
  113. 113. 113 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. www.indiandentalacademy.com
  114. 114. 114 MODELING  Bone modeling involves independent sites of resorption and formation that change the size and shape of a bone. www.indiandentalacademy.com
  115. 115. 115 CONTROL FACTORS FOR BONE MODELING – Mechanical Peak load in Micro strain. 1. Disuse atrophy <200. 2. Bone Maintenance 200— 2500. 3. Physiological Hypertrophy 2500— 4000. 4. Pathological Overload >4000. • www.indiandentalacademy.com
  116. 116. 116 • Endocrine. 1. Bone metabolic hormones-PTH,Vit D,Calcitonin. 2. Growth Hormones-Somatotropin,IGF 1,IGF 2. 3. Sex steroids-Testosterone,Estrogen. www.indiandentalacademy.com
  117. 117. 117 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 www.indiandentalacademy.com
  118. 118. 118  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. www.indiandentalacademy.com
  119. 119. 119 Functions of Remodeling 1. Progressively change the size of whole bone 2. Sequentially relocate each component of the whole bone 3. Progressively change the shape of the bone to accommodate its various functions www.indiandentalacademy.com
  120. 120. 120 1. Progressively change the size of whole bone 2. Sequentially relocate each component of the whole bone 3. Progressively change the shape of the bone to accommodate its various functions Functions of Remodeling www.indiandentalacademy.com
  121. 121. 121 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 . www.indiandentalacademy.com
  122. 122. 122 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. www.indiandentalacademy.com
  123. 123. 123 Displacement  Displacement is a physical movement of the whole bone as it remodels  Two types: primary displacement secondary displacement www.indiandentalacademy.com
  124. 124. 124 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 www.indiandentalacademy.com
  125. 125. 125 Secondary displacement  It is the movement of a whole bone caused by the separate enlargement of other bones www.indiandentalacademy.com
  126. 126. 126 Combination of remodeling & displacement  Both these mechanisms carries out two general functions  Positions each bone  Designs and constructs each bone www.indiandentalacademy.com
  127. 127. 127 Rotation  According to Enlow, growth rotation is due to diagonally placed areas of deposition and resorption  Two types  Remodelling rotations  Displacement rotations www.indiandentalacademy.com
  128. 128. 128 Principle of ‗Area relocation‘ Both remodeling and displacement together cause a shift in existing position of a particular structures with reference to another . www.indiandentalacademy.com
  129. 129. 129 Counter part principle  ―Growth of any given facial or cranial part relates specifically to other structural and geometric counterparts in the face and cranium‖ - Enlow www.indiandentalacademy.com
  130. 130. 130 Growth equivalent principle This principle proposed by Hunter & Enlow relates the effects of cranial base growth on the facial bone Growth. www.indiandentalacademy.com
  131. 131. 131www.indiandentalacademy.com
  132. 132. 132 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. www.indiandentalacademy.com
  133. 133. 133 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 www.indiandentalacademy.com
  134. 134. 134 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. www.indiandentalacademy.com
  135. 135. www.indiandentalacademy.com 135 Thank you For more details please visit www.indiandentalacademy.com

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