Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing dental education

www.indiandentalacademy.com


CONTENTS







Introduction
Growth:pattern ,variability ,timing
Growth modification
Growth prediction
Assessment of growth direction
Assessment of growth potential


INTRODUCTION


GROWTH




TODD: GROWTH IS INCREASING IN SIZE.
PROFITT: GROWTH IS INCREASE IN SIZE OR
NUMBER.



Growth is a dynamic process with a stable pattern
of changes resulting in the increase in physical
size and mass during it’s course of development.



Thus, growth is a three-fold process “SELFMULTIPLICATION,DIFFERENTIATION,ORGAN
IZATION” each according to it’s own kind.A
fourth dimension is TIME.

DEFINITIONS OF DEVELOPMENT:
 Todd:
“Development is progress towards
maturity”.
 Moyers : “Development refers to all the
naturally occurring unidirectional changes in the
life of an individual from its existence as a
single cell to its elaboration as a multifunctional
unit terminating in death. Thus, it encompasses
the
normal
sequential
events
between
fertilization and death”


GROWTH: PATTERN , VARIABILITY
AND TIMING

PATTERN
VARIABILITY
TIMING




The first important feature of growth
corresponds to Pattern
It reflects proportionality
 The physical arrangement of the body at
any one time is a pattern of spatially
proportional parts.
 There is higher level pattern of growth
which refers to changes in these spatial
proportions over time.



NORMAL GROWTH PATTERN: Not all tissue
systems of the body grow at the same rate.Muscular and
skeletal elements grow faster than the brain and CNS.
PREDICTABILITY:
The proportional relationships can be specified
mathematically and the difference between a growth
pattern is the addition of a time dimension.
VARIABILITY :
Variability in growth and development can be expressed
quantitatively to categorize people as normal or abnormal.
It is usually assessed with peer group of children.

TIMING
Its final major concept in physical growth &
development



Variation in timing arises because the same event
happens for different individuals at different TIME



The biologic clocks of different individuals are set
differently.

Cephalocaudal Gradient of Growth





Fetal head size - 50% of total body length.
Head&face size - 30%
Adult head size - 12%

Ceph – head
 Caudal-feet
 this simply means increase in
growth from head to feet





Changes in head and face during growth


SCAMMONS GROWTH CURVE

200
Lymphoid

Percent of Adult size

Neural

100
General

Genital

0
Birth

10 years

20 years


RHYTHM AND GROWTH SPURTS


The rate of growth is most rapid at
beginning of cellular differentiation
which increases until birth and
decreases thereafter*



Postnatally growth does not occur in
a steady manner. There are periods
of sudden rapid increases which are
termed as growth spurts.



Three types of growth spurts
Name of Spurt
1. Infantile / childhood growth
spurt

Female
3 years

Male
3 years

2. Mixed dentition /Juvenile growth 6-7 years
spurt

7-9 years

3. Prepubertal / adolescent growth
spurt

14-15
years

11-12 years


CLINICAL SIGNIFICANCE OF
GROWTH SPURTS
1.

2.

3.

Differentiate growth changes are
normal or pathologic
Treatment of skeletal discrepancies
is more advantages in mixed
dentition period
Pubertal growth spurt offers the
best time in cases like
predictability, treatment direction,
time and management.

4. Arch expansion is carried out during the
maximum growth period.

5. Orthognathic surgery should be carried
after growth ceases.


GROWTH MODIFICATION
TREATMENT


It is procedure of INTERCEPTIVE
ORTHODONTICS

Definition:
“It has been defined as that phase of the
science and art of orthodontics employed
to recognize and eliminate potential
irregularities and malpositions of the
developing dento-facial complex”.


Diagnostic Procedures


Clinical Examinations :



The physical status or the build, height &
weight are measured and accordingly the
body types can be divided into
Ectomorphic –tall and thin physique
Endomorphic –average physique



Mesomorphic –short and obese physique



Extra oral Examination:









Size and shape of Head
Dolicocephalic-long and narrow head

Mesocephalic-average head shape
Brachycephalic-broad and short head shape

2. The form of face :




Mesoprosopic-average or normal facial form
Euryprosopic-broad and normal facial form
Leptoprosopic-long and narrow facial form

Facial profile and divergence :


To establish this the patient has to be placed in a
natural head position.



Convex profile – Skeletal class II malocclusion.



Concave profile – Skeletal class III malocclusion.




Divergence:
“Divergence of the face is defined as
an anterior or posterior inclination of the
lower face in relation to forehead”

•

3 types of facial divergence



It is purely influenced by ethnic or racial
background

VISUAL TREATMENT OBJECTIVE
THE VISUAL TREATMENT OBJECTIVE {VTO} REPRESENTS A
“CEPHALOMETRIC SETUP” WHICH INCLUDES THE EXPECTED
GROWTH AND TREATMENT CHANGES AS PROJECTED FROM THE
ORIGINAL MALOCCLUSION AND FACIAL MORPHOLOGY.
 This treatment forecast was developed by Ricketts and
named by Holdaway.
 VTO is a treatment design procedure that
1.Changes the areas due to normal growth,the cranial base,
chin and maxilla.
2.Changes the areas affected by orthopaedic alteration.
3.Visualises the orthodontic movement of the teeth within
the jaws to a more normal relationship.







Treatment for a growing patient must be
planned and directed to the face and
structure that can be anticipated in the
future.
The VTO forecast is valuable for
orthodontists self improvement, in that it
permits him to set his goals in advance.
Identification of discrepancies between
goals and results provide him with
objective picture through which his
treatment could be improved.

Class II div I
with full
occlusion

6mm of cuspal
advancement into
class I relation


After VTO

FUNCATIONAL ANALYSIS
Postural rest position


In order to determine the postural rest position
the patients orofacial musculature must be
relaxed.



Muscle exercises like the tapping test can be



1.
2.

used to relax the mandible*
The moment of the mandible from the rest
position to full articulation is analysed in 3
planes of space ,this closing movement of the
mandible can be divided into 2 phases.
Free phase.
Articular phase*



a.
b.

c.

For complete functional
examination the following
condition should be differentiated
Pure rotation.
Rotation movement with anterior
sliding component.
Rotation movement with posterior
sliding component.









For example: A class II Malocclusion can manifest in
3 ways.
Firstly when the mandible moves from rest to
occlusion without any deviation. It means that
neuromuscular and morphologic relationship
correspond to each other. As there is no functional
disturbances it is a true class II Malocclusion.
Secondly when there is a anterior gliding
component. It means that the mandible slides
forward into habitual occlusion hence class II Mal
relationship is actually more severe than what you
see.
Thirdly: Where there is a posterior gliding
component. The mandible glides backwards into a
class II occlusion and it is not true class II
malocclusion.



Vertical Relationship:
1. True Deep over bite
2. Pseudo deep over bite *



Transverse relationship:

1.

This analysis is particularly relevant for
differential diagnosis of cases with unilateral
posterior cross bite.
Depending on the functional analysis, two
types of skeletal mandibular deviations can
be differentiated.
Laterognathy

2.

Laterocclusion





*


RADIOGRAPHIC AND
CEPHALOMETRIC EVALUATIONS
1.OPG (Orthopantomograph):




It gives valuable information like
unerupted
supernumery,
unusual
crown and root forms, congenital
missing and details of 3rd molars can be
obtained.
It gives valuable information like stages
of
Germination,
the
degree
of
development of teeth is compared to
fixed scale.

2. CEPHALOMETRICS:


The

introduction

of

radiographic

cephalometrics in 1931, was to be used
originally for research in craniofacial growth
pattern and as clinical tool for the study of
malocclusion

and

underlying

problems.

skeletal

3. Hand Radiograph:


Chronological age is not sufficient for assessing the
developmental stage and somatic maturity of the
patient, so that the biologic age has to be
determined.



Assessment of the skeletal age in often made with
the help of hand radiograph



Analysis of skeletal maturity up to 9 years, the
stages of mineralization of the carpal bones must be
determined
thereafter
metacarpal
bones
&
phalanges should be evaluated



Various indicators for development and maturity are
established which occur regularly in a definite
sequence during skeletal development.

Growth Related Problems
MALOCCLUSIONS:
I. Skeletal Malocclusions:


The skeletal malocclusion three planes of
space namely
1. Sagittal plane:
* Prognathism
*

Retrognathism

2. Transverse plane:
* Crossbite
3. Vertical plane:
* Open bite
*

Deep bite


DENTOALVEOLAR MALOCCLUSION
Malposition of individual
teeth

Sagittal plane

Malposition of groups of
teeth

Transverse plane

Malocclusion

Vertical plane


SAGITTAL DENTOALVEOLAR
MALOCCLUSION*
Class I Malocclusion
 Class II Malocclusion


Class II Div 1 Malocclusion
 Class II Div 2 Malocclusion






Class II, Subdivision

Class III Malocclusion




True Class III
Pseudo Class III
Class III subdivision


CLASS II MALOCCLUSION
DIVISION I

DIVISION II


Cephalometric Characteristics of
Class II Division 1 Malocclusion #





The relationship of maxilla to cranial base
showed no significant differences
The mandible was significantly retrusive with
the chin located further posteriorly resulting in
a larger angle of facial convexity
Maj & co-workers suggested:
In some cases the inclination of anterior
teeth either exaggerates or camouflages the
differences between the bony bases. They
concluded that skeletal differences not due to
abnormal development in size of any specific
part but rather were result of abnormal
relationship between the parts in the direction
of discrepancy

#(Seminar in ortho, Vol12, No.1 (Mar)06)

Cephalometric Characteristics of
Class II Division 2 Malocclusion #






According to wallis class II division2 had posterior
cranial base larger than division1
He noted in a typical division2 cases relatively
more acute gonial and mandibular plane angles,
shorter lower anterior face height and excessive
overbite.
Hedges noted a larger angle of convexity in
division 2 cases
Hedges concluded only consistent cephalometric
finding was the lingual axial inclination of the
maxillary central incisors.

# (Seminar in ortho, Vol12, No.1 (Mar)06)

CLASS III MALOCCULSION


Malocclusions Occuring in Vertical
Plane
1.
2.

Open Bite
Deep Bite

1. Open Bite
“Open bite is a Malocclusion that occurs
in the vertical plane, characterised by
lack of vertical overlap between the
maxillary and mandibular dentition”.


DEEP BITE
Definition:
“Deep bite is defined as a condition
of excessive overbite where the vertical
measurement between the maxillary
and mandibular incisal margins is
excessive when the mandible is brought
into habitual or centric occlusion”.
– Graber.


MALOCCLUSION IN TRANSVERSE
PLANE


Cross Bites
“Cross Bite is defined as a condition
where one or more teeth may be
abnormally

malposed

buccally

or

lingually or labially with reference to the
opposing tooth or teeth”. – Graber


GROWTH MODIFICATIONS


Concepts and principles of functional
jaw therapy:



Norman Kingsley –(1879)



Pierre Robin –(1902)



Alfred Rogers –(1918)



Viggo Andresen – (1936,1939)










Norman kingsley was first to use forward
positioning of mandible in orthodontics
Jumping of bite was very popular method
in those times
pierre robin designed an
appliance monobloc
alfred p rogers showed
importance of muscles in growth and
development




Viggo andresen came up with
retention activator



Andresen’s activator was a
milestone for removable appliances


Myotonic – muscle mass



Myodynamic-muscle activity




Principles :






In 1883 roux hypothesis
forces , function and form

His working hypothesis became background for
general orthopedic and functional appliances

Treatment principles:


Force applicaton



Force elimination

showed natural



Neuromuscular response

:



Success of functional appliance depends on
this response



Functional appliance considered as biologic
because of force elimination and growth
guidance functions


FUNCTIONAL APPLIANCES


DEFINITION:
“A REMOVABLE OR FIXED APPLIANCE THAT ALTERS

THE POSTURE OF MANDIBLE AND TRANSMITS THE FORCES
CREATED BY THE RESULTING STRETCH OF THE MUSCLES
AND

SOFTTISSUES

AND

BY

THE

CHANGE

OF

THE

NEUROMUSCULAR ENVIRONMENT TO THE DENTAL AND
SKELETAL TISSUES TO PRODUCE MOVEMENT OF TEETH
AND

MODIFICATIONS

OF

GROWTH“-

ORTHODONTIC TERMS )


( GLOSSARY

OF



CLASSIFICATON:


TOOTH BORNE ACTIVE APPLIANCES
EX : BIONATOR, MODIFIED ACTIVATOR WITH
EXPANSION SCREWS



TOOTH BORNE PASSIVE APPLIANCES
EX:ACTIVATOR ,BIONATOR ,HERBST APPLIANCE



TISSUE BORNE PASSIVE APPLIANCES
EX:FUNCTIONAL REGULATOR OF FRANKEL



MYOTONIC APPLIANCES
MYODYNAMIC APPLIANCES



REMOVABLE FIXED APPLIANCES
EX : ACTIVATOR ,BIONATOR
FIXED FUNCTIONAL APPLIANCES

o

Group 1 appliances ex:oralscreen,inclined
plane

o

Group 2 appliances ex:activator,bionator

o

Group 3 appliances ex:frankel appliance,
vestibular screen


Activator





Andresen developed a mobile loose
fitting appliance which was
progenitor of kingsley appliance.
“Biomechanic working retainer “
Andresen and haupl teamed up to
create appliance called Activator.


Philosophy of treatment


Individual optimum :




The basis of treatment was to stimulate
condylar changes by relocating the mandible
anteriorly thus achieving desired occlusion

Efficacy of activator:
According to Andresen and haupl(1955)
concept myotatic reflex activity and isometric
contractions induce musculoskeletal adaptation by
introducing new mandibular closing pattern.
A fundamental requirement for condylar
growth is stimulation of lateral pterygoid muscle



Skeletal and dentoalveolar effects of
activator:
 Third level of articulation (moffet)
 Construction bite
 Depends on growth potential
 Condylar growth translates mandible
downward and forward direction .
 Effective during tooth eruption and
alveolar bone apposition.

o

Force analysis :

Static forces
 Dynamic forces
 Rhythmic forces
o



Modifications:
 Bow

activator a m schwarz
 Wunderers modifications
 Cybernatic of schmuth or
reduced activator
 The propulsor



Cutout or palate free activator



The karwetzky modification
Herrens activator .




Bionator


Development and Principles:
 Balters

developed Bionator 1950
 Balters hypothesis states :
The equilibrium between the
tongue and circumoral muscles is
responsible for shape of the dental
arches and intercuspation.




Balters hypothesis supports the early
function and form concept of Vander
Klaaw and functional matrix theory of
moss



Principle of treatment is to modulate the
muscle activity




Efficacy:



Allows to wear day and night





Reduced size
Constant influence on tongue and perioral
muscles

Skeletal and dentoalveolar effects :
Limited effectiveness in case of skeletal
disturbances
 Distortion of appliance due less acrylic
support



Bionator types :


Standard appliance



Openbite appliance



Class III or Reversed bionator


FRANKEL FUNCTION REGULATOR


FRANKEL PHILOSOPHY :
BUCCAL SHIELDS AND LIP PADS HOLD the
buccal and labial musculature away from the teeth
and investing tissues, eliminating any possible
restrictive influence from this functional matrix .
Frankel conceives his vestibular restrictions as
artificial “ought to be “ matrix .


Functional matrix concept of Melvin Moss:
 Buccal shields of frankel directly alter the soft tissue
configuration, increasing the oral volume, that is the
capsular matrix that allows the muscle to exercise and
adapt and improve.

 The impact of the space increase
on the basal development of mandible
has been suggested.

 The term translative growth gives a new credence to
the theoretic and therapeutic aspect of orthopedic
treatment with frankel.




Frankel has stressed another
theoretic action
Tissue tension created by
shields and pads exerts contiguous
periosteal tissue pull leading to
increased bone activity .


TYPES OF FRANKEL APPLIANCE:
TYPES

USES

1)FR 1
---A) FR1a ----

CL 1 AND CL 2 DIV 1 MALOCCLUSION.
CL 1 MALOCCLUSION WITH MINOR
CROWDING
CL I WITH DEEP BITE.
B) FRI b ---- CL 2 DIV 1 MALOCCLUSION WITH OVERJET
LESS THAN 5 mm.
C) FRI c ---- CL2 DIV 2 MALOCCLUSION WITH OVERJET
MORE THAN 7mm.

2) FR 2

----

CL 2 DIV 1 AND DIV 2 MALOCCLUSIONS.

3) FR3

----

CL 3 MALOCCLUSIONS.

4) FR4

----

OPEN BITE AND BIMAXILLARY PROTRUSION.

5) FR 5

----

HIGH MANDIBULAR PLANE & VERTICAL
MAXILLARY EXCESS

TWIN BLOCK


Development of twin block :

WILLIAM J CLARK in 1977


Goal was to produce a technique to
maximize growth response



Designed for full time wear to take
advantage of all functional forces
applied to the dentition .

Proprioceptive stimulus to growth :


Inclined
plane
important role .

mechanism



Occlusal
forces
provide
constant
proprioceptive stimulus influencing growth
rate and trabecular structure of supporting
bone .

plays

an

CLINICAL RESPONSE TO TREATMENT
ACCORDING TO MCNAMARA (1980) :
“THE PLACEMENT OF APPLIANCES RESULTS IN AN
IMMEDIATE CHANGE IN THE NEUROMUSCULAR
PROPRIOCEPTIVE
RESPONSE
PROVIED
ALL
PHASIC AND TONIC MUSCLE ACTIVITY IS
AFFECTED ,RESULTING MUSCULAR CHANGES
ARE VERY RAPID AND CAN BE MEASURED IN
TERMS OF MIN,HOURS & DAYS STRUCTURAL
ALTERATIONS ARE MORE GRADUAL & ARE
MEASURED
IN
MONTHS,WHERE
BY
THE
DENTOSKELETAL
STRUCTURES
ADAPT
TO
RESTORE A FUNCTIONAL EQUILIBRIUM TO
SUPPORT THE ALTERED POSITION OF MUSCLE
BALANCE”

INDICATIONS :
 The primary indication for twin
block is early mixed dentition of
class II division 1 malocclusion .



↓ overjet and correct distal occlusion
improve arch form by transverse or sagittal
development .


Pre Treatment


Post Treatment


Studies of functional appliance therapy
13 studies were conducted to know the
concepts influencing the functional
appliance therapy.
First study (woodside 1975):
To know the effectiveness of
activator treatment during day and
night on mandibular length.




Second study and third study
(altuna,woodside 1977;1985):

These studies attempted to
clarify the experimental
conditions to achieve increased
mandibular length .




The fourth study (woodside et al 1975):

It tested the effectiveness of
activator with wide opening in
the construction bite (8mm
beyond the rest ).
o

The fifth study (shapera 1974):
This study demonstrated a
recovery from midface restriction
within 5years of treatment in sample
of patients.




The sixth investigation study (woodside
1985):
It was conducted to compare differences
in electromyographic (emg) activity
generated in the lateral pterygoid
muscle by frankel function regulator and
activator .

To test hypothesis on activity of
muscle on proliferration of condylar
tissue.




The seventh study (sessle et al):
A sample of six juvenile
monkeys (macaca fasicularis)
was studied to test the
longitudinal effect of functional
appliances on jaw muscle
activity .




The eighth and ninth
study(sectakof1992 ;yamin1991 ) :

These studies tested
functional activity in the
muscles of mastication after
insertion of functional
appliance.




The tenth study (organ 1979):
Tested the hypothesis
on extention of buccal shield
into the soft tissues of the oral
vestibule


The

eleventh study (woodside et
al 1987):
A sample of juvenile
monkeys was studied to assess
the remodelling changes in
condyle and gleniod fossa .




o

The twelfth study (voudouris,1988):
found similar changes
in mixed dentition animals .
The thirteenth study
(angelopoulos1988):
showed glenoid fossa
relocation helps correcting class
II dysplasia.



Conclusion of studies :
Part time use of appliance do not
produce any effect on mandibular
length
 Large or moderate vertical opening of
construction bite redirects the
maxillary growth direction.
 The function regulator does not
increase bone formation at apical
base but rather at alveolar crest.





Functional regulator & activator
create similar increased amount of
LMP activity at appliance insertion.



Chronic condylar unloading produces
rapid downward and forward
relocation of glenoid fossa.


A new parameter for estimating
condylar growth direction :


Effects of STH and TESTOSTERONE:

According to
Petrovic et al, stutzmann,gasson et al





supplementary lengthening of mandible
compared to maxilla
increased stimulation of lateral pterygoid muscle
shows more posterior location of mitosis in
condylar cartilage

decreased stimulation shows mitosis less
posterior location




If sth or testosterone level rises beyond
certain level (STH3 &STH4)
jumping of bite
↓
new suboptimal occlusal adjustment
↓
increased lpm activity
↓
increased number of dividing cells in condylar
cartilage
↓
more posterior growth direction


Growth rotation and alveolar bone
turnover of the mandible


Anterior mandibular growth rotation rate
of alveolar bone formation at first
mandibular Ist premolar is greater than
posterior growth rotation



Mitotic index in ramus is higher in anterior
growth rotation than posterior growth
rotation




Conclusion:

1>better understanding of biologic
phenomena in mandibular growth rotation .

2> diagnosis and projection of treatment
effectiveness in dentofacial orthopaedics


Servosystem concept and its tentative causal
interpretation in method of operation of functional
appliances

Two categories :
1>postural hyperpropulsor ,activator ,class II


elastics ,frankel appliance ,clark
twinblock ,baltors bionator

↓ effect

movement of mandible

↓

stimulates condylar cartilage


2>herren & lsu activator ,harvold &hamilton activator
extraoral forward traction on the mandible

↓ effects
sagittal repositioning of mandible


Glenoid Fossa

functional appliances

↓
↑se contractile activity of lpm
↓
intensified activity of retrodiscal pad
↓
growth stimulating factor
●enhancement of local mediators
● ↓se local regulators
↓
change in condylar trabecular orientation
●additional growth of condylar cartilage
↓
lengthening of mandible

Importance of masticatory muscle
function in dentofacial growth *





Elevator muscles influence transverse
and vertical facial dimensions .
Increased loading of the jaws associated
with masticatory muscle function shows
increased sutural growth and bone
apposition.
strong masticatory muscles have
homogenous facial morphology in
contrast to individuals with weak
masticatory muscles

* Sem in ortho ,vol12 no2(june)2006


According to animal studies :

Altering consistency of diet
shows changes in biting force level,
masticatory activity and behaviour .


The influence of tension created
by masticatory muscles apply to
craniofacial skeleton there by
altering its growth .



Research studies shows that masticatory
muscles are able to influence craniofacial
growth of man provided tension they
apply to facial bone structures is above a
certain threshold ie mild overload window
(frost) .
 Epigenetic influences of masticatory
muscles force on craniofacial growth may
apply only in presence of increased
muscle activity .

GROWTH PREDICTION
“GROWTH PREDICTION IS THE FORECASTING OF
THE DIRECTION AND AMOUNT OF GROWTH OF
THE MAXILLA AND MANDIBLE {HORIZONTAL
AND VERTICAL GROWTH TRENDS} AS WELL AS
THE TIMING OF THE ADOLESCENT GROWTH
PERIOD.”
WHAT IS THE NEED FOR IT????
• HELPS THE CLINICIAN DEALING WITH INTERCEPTION AND /OR
CORRECTION OF DENTOFACIAL MALOCCLUSIONS.
• DECISIONS CAN BE MADE ABOUT THE NEED FOR TREATMENT.
• DECISIONS COULD BE MADE ABOUT THE TIMING, TYPE AND
LENGTH OF TREATMENT.



d’Arcy thomson analysed growth of
seashells and classified them according to
patterns of enlargement and developing
equations to fit the process .



According to aristotle
“ The process of growth where upon the

addition of a figure or body leaves the
resultant figure or body similar to original is
called gnomonic growth “




Second characteristic of nautilus :
Gnomonic growth can be described by
particular kind of curve logarithmic or
equiangular spiral.




According to thompson :
“Any plane curve proceeding from a fixed
point or pole and such that the vectorial
area of any sector is always a gnomon to
the whole preceding figure is called an
equiangular or logarithmic spiral if such
relationship could be discovered in the
face ,then prediction about its growth
would be feasible as in the nautilus”


Gnomonic growth of human head


Growth of craniofacial spaces :
according moss study indicate that
orofacial capsular matrices
particularly the oropharyngeal
functioning spaces manifest
gnomonic growth .




Fig nasal f sp

Nasal functioning spaces of human fetuses of various crown-rump
lengths (Left). The oral functioning spaces of the same fetuses (right)



Fig v1 v2 v3


Neurotrophism


According to moss :



Great extend of messages necessary for
controlling growth derived from the nerves
that innervate



Pathway of inferior alveolar nerve is
considered a logarithmic spiral
DNA dominates craniofacial growth where
messages are carried to distant organs by
axoplasmic flow




Logarithmic growth of human
mandible


Arcial growth of human mandible




Methods of predicting facial growth
changes *
1. longitudinal method
2. metric method
3. structural method
4. computerised method

* (angle orthodontist vol 70 no6 2000)


Computerized prediction method


Tool of analysis and not method of
analysis.

ADVANTAGE:
facilitates testing and

applying more complex formulas to
growth prediction.


CLINICAL IMPLICATIONS


ASSESSMANT OF GROWTH DIRECTION
 Rotation

of jaws during growth

Terminology:
Condition

Bjork

Shudy

Anterior growth
greater than
posterior

Forward rotation

Clockwise
rotation

Posterior growth
greater than
anterior

Backward
rotation

Counter
Clockwise
rotation


Condition

Bjork

Solow,
Houston

Profitt

Rotation of
mandibular Core
relative to
cranial base

Total rotation

True rotation

Internal rotation

Rotation of
mandibular
plane relative to
cranial base

Matrix rotation

Apparent
rotation

Total rotation

Rotation of
mandibular
plane relative to
core of mandible

Intramatrix
rotation

Angular
remodelling of
lower border

External rotation


ROTATION OF MANDIBLE


SIGNIFICANCE OF MANDIBULAR ROTATION






Major factor in development of malocclusion
Posterior rotation – retrogenia.
Anterior rotation - progenia.
Plays important role in treatment planning.


Growth related rotation of mandible


Clinical implication of growth rotation








Aetiological assessment.
Determine nature of anamoly
Prognostic evaluation
Determining possible forms of treatment
and indications
Choosing principle of treatment
Assess stability of treatment results


Assessment of growth potential
According to ricketts
 magnitude .
 direction .
 timing .



Growth assessment parameters


Krogman defines five ages of
childhood
1.chronological age
2. biologic age
morphological age
skeletal age
dental age
circumpubertal age


3.behavioural age .
4. mental age .
5. self concept age .


1> chronologic age :“It is defined as age measured
by years lived since birth “
helps to categorise
early

maturity
average maturity
 late maturity



Biologic age :1 somatotypic age
2 height and weight age




Somatotypic age :
according to sheldon
ectomorph
mesomorph
endomorph




Height and weight age :



Convenient determinant of
developmental age .

It is compared on standard
growth curve of certain child to
characterise a childs height
compared to that children of same
chronological age .




Girls

Boys


Skeletal age :

anatomical regions
small to restrict radiation exposure
and expense .
Many ossification centres which
ossify at separate times
Easily accessible





Regions normally used for age
assessment
head and neck :skull
cervical vertebrae
upper limb : shoulder joint –scapula
elbow
hand wrist and fingers




Lower limb – femur and humerus
hip joint
knee
ankle
foot tarsals
metatarsals
phalanges




Hand wrist radiograph :
It is one of the region which is most
suitable to study growth .
ANATOMY :
4 GROUPS OF BONES
1.DISTAL ENDS OF LONG BONES OF FOREARM
2.CARPALS
3.METACARPALS
4.PHALANGES


Anatomy of Hand Wrist Radiograph
Distal phalanx
Middle phalanx


FIG
Proximal phalanx

Metacarpal [5 ]
Scaphoid
Lunate
Pisiform,
Triquetral,

Trapezium,
Trapezoid,
Capitate,
Hamate

Carpal [ 8 ]
Radius Distal ends of

Ulna

long bones

RADIOLOGICAL ASSESSMENT OF PREDICTION
OF SKELETAL GROWTH


1 GREULICH AND PYLE METHOD



2 BJORK GRACE AND BROWN METHOD



3 FISHMANS SKELETAL MATURITY
INDICATOR



4 MATURATION ASSESSMENT BY HAGG
AND TARANGER AND KR



5 SINGERS METHOD OF ASSESSMENT




Skeletal maturation evaluation
using cervical vertebrae :
According to hassell & farman




Shapes of cervical vertebrae differ at
each level of skeletal development.
To determine existence of potential
growth.


Tooth mineralization as an indicator
of skeletal maturity :

Entire deciduous and mixed
dentition period .

Calculating is made using a point
evaluation system (demirjian et al1973,
schopf 1970) .





Pubertal /sexual age :
According to Hagg and taranger
 Girls if the menarche has occurred ,peak height

velocity attained
deaccelerating

→

growth rate is



Boys with prepubertal voice change
spurt



Boys with male voice

→ pubertal

→ growth rate is
deaccelerating




NEURAL AGE :
developmental landmarks

year age(months)
2
4
6
8
10

Characteristic features
Follows moving objects with
eyes
Can sit for short time.
Grasps objects
May unaided
Creeps tries to help with

feeding

Year
1
1.5
2
word
3
4
5
6

age
cruises holding onto rail of cot
18 walks , runs awkwardly and
stiffly
24 runs without falling ,uses
three
sentences
walks erect , stand on one foot
draws ,copies ,prints letter
can tie shoe lases ,can read well
reads and write well.




mental age :
determines outlook of patient
towards treatment .



determines standard capacity of child to read



Intelligent quotient (IQ) :
It is mental age expressed as a
percentage of the chronological age


Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy

Similar to Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Clinical implications of growth and development /certified fixed orthodontic courses by Indian dental academy