This document defines key terms related to growth and development and summarizes research studies. It begins by defining growth, development, and related terms. It then discusses patterns of growth including differential growth and the cephalocaudal gradient. The document summarizes several major longitudinal growth studies, including the Bolton Brush, Burlington, and Iowa Child Welfare studies. It concludes by outlining different methods used to study bone growth, both at the macro and microscopic levels.
A Critique of the Proposed National Education Policy Reform
Growth and development (2)/certified fixed orthodontic courses by Indian dental academy
1. 1
GROWTH & DEVELOPMENT
DEFINITIONS AND
TERMINOLOGIES
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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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.
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―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.
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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
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“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
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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‖
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•Translocation –
― It is a change in position‖
•Maturation –
―It is the emergence of personal
characteristics and behavioural
phenomenon through growth processes‖
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Timing and sequential change
a. Prenatal growth
b. Postnatal growth
c. Maturity
d .Old age
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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
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Proportional change
Eg-Head of the infant
Functional change
Eg-Secretion , production of enzymes,
hormones
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Maturational change
-Towards a period of stability and
adulthood
Compositional change
Eg-Eye pigmentation
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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
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Major themes of
development
Changing complexity
Shifts from competent to fixation
Shifts from dependent to independent
Ubiquity of genetic control modulated by
environment
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Changing complexity
All level of organisation sub-cellular
to the whole organism
Complexity development
Orthodontics Mixed dentition period
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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.
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Ubiquity of genetic control
modulated by environment
Genetic control of development is
constantly being modified by
environmental interactions
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Correlation between
Growth & Development
Growth anatomic phenomenon
quantitative
Development physiologic
phenomenon qualitative
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Growth
•Increase in size decrease in
size
eg- thymus gland after puberty
Development process of increasing
complexity.
Development=growth+differenciation+translocation
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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
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To identify abnormal occlusal
development at an earlier stage
use of growth spurts
Surgery initiation
Planning of retention regime
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Normal features of
Growth & Development
pattern
-Differential Growth
-cephalocaudal gradient of growth
Variability
Timing, rate & direction
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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.
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DIFFERENTIAL GROWTH
Different organs grow at different
rates to a different amount and at
different times.
Scammon‘s curve of growth
-Richard scammon
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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.
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•It illustrates the change in overall body
proportions during normal growth and
development.
•Imp aspect of pattern is its predictability.
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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.
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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
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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‖
•
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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.
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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
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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
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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
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• Types of growth data
• Methods of gathering growth data
• Longitudinal growth studies
• Methods of studying bone growth
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Types of growth data.
Opinion
Observations.
Ratings and
rankings.
Quantitative
measurements.
direct data.
indirect data.
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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.
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• 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.
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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.
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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
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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
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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.
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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
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Montreal growth study
Krogman philadelphia growth study
Fels growth study
Implant studies
the mathews implant collection
the hixon oregon implant study
Cleft palate study
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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.
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• 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.
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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.
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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.
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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.
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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.
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• 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.
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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.
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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.
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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.
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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.
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• 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
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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
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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.
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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.
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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
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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.
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• 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.
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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).
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• 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.
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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.
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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.
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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
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• 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.
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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.
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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.
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Mechanism of growth
3 mechanisms at the cellular level
Hyperplasia
Hypertrophy
Secretion of extracellular matter
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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.
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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
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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
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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
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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
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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.
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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
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–Seen in areas like:
– Cranial vault
• Maxilla
• Mandible except condylar
cartilage
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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.
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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 %
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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
.
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TYPE OF BONES
Lamellar bone
Non lamellar bone
Fine cancellous bone
Coarse cancellous bone
Woven bone
Bundle bone
Composite bone
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LAMELLAR BONE
Comprises 99% of human skeleton
Strong highly mineralised
Mineralised in two stages:
primary mineralisation
secondary mineralisation
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Clinical significance
Full strength of lamellar bone supporting
an orthodontically moved tooth is not
attained for upto a year after completion
of active treatment.
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Non Lamellar bone
Makes up fine cancellous bone tissue
No distinct stratification in fibre
orientation
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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.
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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.
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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.
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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
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Coarse cancellous bone
Produced by endosteum only
Irregular marrow spaces containing red
or yellow marrow
Irregularly arranged trabeculae
Present in medulla
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Mechanisms of bone growth
Deposition and resorption
Growth fields
Modelling
Remodelling
Growth movements
drift
displacement
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Deposition and resorption
Bone sides which face
the direction of growth
are subject to
deposition (+) and
those opposite to it
undergo
resorption(-)
…surface principal
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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.
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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.
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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.
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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.
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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.
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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)
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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..
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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
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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.
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Growth sites
Such special
sites do not out
the entire carry
growth process
but the entire
bone takes part
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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.
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MODELING
Bone modeling involves
independent sites of resorption
and formation that change the
size and shape of a bone.
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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.
•
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• Endocrine.
1. Bone metabolic hormones-PTH,Vit D,Calcitonin.
2. Growth Hormones-Somatotropin,IGF 1,IGF 2.
3. Sex steroids-Testosterone,Estrogen.
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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
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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.
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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
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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
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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 .
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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.
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Displacement
Displacement is a physical movement of
the whole bone as it remodels
Two types:
primary displacement
secondary displacement
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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
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Secondary displacement
It is the movement
of a whole bone
caused by the
separate
enlargement of
other bones
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Combination of remodeling &
displacement
Both these mechanisms carries out two
general functions
Positions each bone
Designs and constructs each bone
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Rotation
According to
Enlow, growth rotation
is due to diagonally
placed areas of
deposition and
resorption
Two types
Remodelling rotations
Displacement rotations
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Principle of ‗Area relocation‘
Both remodeling and
displacement together
cause a shift in existing
position of a particular
structures with reference
to
another
.
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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
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Growth equivalent principle
This principle proposed by Hunter & Enlow
relates the effects of cranial base growth on
the facial bone Growth.
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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.
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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
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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.
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