Growth prediction

GROWTH PREDICTION
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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

A reliable method of growth prediction would be an
invaluable asset to orthodontists.
The ability to predict the magnitude and direction of a
patients facial growth early in life would enable the
clinician
• To identify those who require interceptive growth
modification and to ensure that appropriate treatment can
be rendered while growth is possible
• To forgo unnecessary treatment on patients with skeletal
discrepancies whose growth pattern would probably lead
to correction without orthopaedic intervention
Similarly,lengthy attempts at orthopedic correction could be
avoided in patients who ultimately would be best treated
by surgery www.indiandentalacademy.com

•The large variability in the amount and direction of
facial growth in different subjects and the importance of
facial growth for the success of orthodontic treatment has
been generally recognized over the past decade.
•This has led to a marked interest in methods for
predicting the amount and direction of facial growth in
the individual patient.

 So far, two main types of prediction have been used
• The first type uses statistical information on average
growth increments according to the age and the sex of the
subject.
• By adding average increments derived from a normative
sample to the recorded actual facial dimensions of a
patient, this type of prediction estimates the statistically
probable future facial dimensions of the patient. Because
of the properties of statistical rules, such predictions will
be reasonably correct in a majority of cases, but
unfortunately they are less likely to be correct in subjects
whose facial growth deviates markedly from the norm, and
where prediction, from a clinical point of view, therefore is
most needed.

 The second type of approach - selected features of the facial
structure of the patient to predict future developmental trends.
- presence or absence of a series of structural traits in the lower
face,their own growth potential,use of the anterior-to-posterior
facial height proportions,regression equations with a series of
facial dimensions to predict mandibular rotation, and the use of
sophisticated graphic projection techniques.
• The structurally based methods are implicitly based on two
assumptions; namely, (1) the previous facial growth pattern of a
child can be estimated, to some extent, from skeletal structural
traits that can be measured or recognized on the cephalometric
film, and (2) this growth pattern is likely to continue.
• Since facial growth types, which deviate extremely from the
norm, would be expected to leave the most dramatic traces in
facial structure, the structurally based methods should
theoretically predict extreme facial development better than the
methods based on average increments. So far, however, this has
not been documented.

• Although much effort has been devoted to satisfy the immediate clinical
demand for prediction of facial development, less interest has been devoted
to the fundamental question of why the facial development is so variable,
that is, the clarification of the mechanisms that determine or control facial
development.
• An improved understanding of the developmental mechanisms should add a
new aspect to prediction of facial development and thus supplement the
moderately successful statistical and structural predictive methods.
Moreover, it might remove some of the mystery that currently seems to
envelop the art of facial growth prediction.
• Some attempts have been made at describing the mechanisms determining
facial structural development - the functional matrix concept developed by
Moss and coworkers on the basis of work by van der Klaauw and
Dullemeijer on the functional components of the skull. While contributing
greatly to reintroducing the concept that function may influence skeletal
development, it has not provided any method for predicting facial
developmental trends.
• At the other end of the spectrum, the work of Petrovic and coworkers who
developed experimentally refutable cybernetic models for describing the
control of facial structural development may be mentioned. Their work has
produced significant information about systemic and local control factors
and their possible stimulation of condylar growth.

MATHEMATICAL MODELS
 MOSS AND SALENTIJIN proposed a mathematic expression to
describe human mandibular growth.
 RICKETTS created a cephalometric technique for drawing an arc along
which the mandible can be expected to grow.
The above mathematical models that describe mandibular growth have
evolved from the following fundamental concepts:
1. D’ARCY THOMPSON’S STUDY OF SEASHELLS.
2. MOSS’S INTERRELATED THEORIES OF FUNCTIONAL
MATRIX,GNOMONIC FACIAL GROWTH AND FACIAL
NEUROTROPHISM.

GNOMONIC GROWTH
THE CHAMBERED NAUTILUS
Thompson analysed the growth of certain sea shells.
The chambered nautilus has two fundamental
characteristics:
The shell grows in size but does not change it’s
shape.Although the shell grows asymmetrically ,the original
shape remains constant.
The process of growth whereupon the addition of a figure
or body leaves the resultant figure or body similar to the
original is called GNOMONIC GROWTH.

The gnomonic growth can be described by a particular kind of
curve called as the LOGARITHMIC or EQUIANGULAR
SPIRAL.
The spiral is characterized by the movement of a point away from
the pole along the radius vector with a velocity increasing as it’s
distance from the pole.The spiral of the Nautilus has been fitted to
a precise formula:
ө =k log r.
Since the future growth of the animal will
continue along that curve ,the spiral can
be generated at any time to reveal the
final shape. www.indiandentalacademy.com

Gnomonic growth of the human head
Moss indicates that orofacial capsular matrices, particularly the
oro-naso-pharyngeal functioning spaces manifest gnomonic
growth.In one study , heads of human fetuses with crown-rump
length ranging from 26 to 163 mm were sectioned midsagitally
for direct measurements of the oral ,nasal and the pharyngeal
cavities.
On analysis, the oral and nasal functioning spaces enlarge but do
not change shape.

Moss cited the work of Burdi as the finest example of
gnomonic growth of the nasal functioning space.Using the
cephalometric points sella(S), nasion (N), anterior and
posterior nasal spines(ANS,PNS), and septal point (SP),
Burdi developed the representation of the growth of the
human fetal nasal space during the second trimester.
The space has resituated the surrounding
skeletal units in such a way that the overall
shapes remain similar.
Moss constructed a logarithmic
spiral as suggested by gnomonic
growth.

Ricketts has suggested a number of gnomonic figures that are
correlated to three branches of the trigeminal nerve.The focal
point for the region supplied by one of these branches is the
foramen associated with the nerve.
V1 , V2, V3 = BRANCHES OF THE TRIGEMINAL NERVE
VERTEX OF ORBITAL ANGLE(V1) – SUPERIOR ORBITAL
FISSURE.
VERTEX OF NASAL ANGLE (V2) – FORAMEN ROTUNDUM.
VERTEX OF ORAL REGION (V3) – MANDIBULAR FORAMEN.

When lines are extended from the
superior orbital fissure base ,the content
of orbit appears to expand within a
constant angle.
The nasal angle A-pt-ANS describes
growth of nasal capsule.
The oral cavity enlarges within the angle
ANS-Xi-Po.,created by locating the
vertex at Xi,a point that represents the
mandibular foramen .
This property,increase in size without
change in shape satisfies the definition of
gnomonic growth.

NEUROTROPHISM
The functional matrix theory disclaims any intrinsic genetic
determination by bone cells and therefore the information about
the rate and limitation of growth must exist somewhere in the
capsules.Moss contends to a great extent that the message
necessary for controlling growth are derived from the nerves that
innervate these capsules.ultimately the ,DNA , that dominates
craniofacial growth, resides in the chromosomes of brain
cells.RNA or other messages are carried to the end organs by
axoplasmic flow.
The process of neurotrophism or neural nourishment dictates that
at no time are the nerves to be subjected to torsion,compression ,or
tension. This is true with respect to the inferior alveolar nerve
during the development of lower jaw.As a vital constituent of
orofacial capsule ,the Inferior alveolar nerve follows a logarithmic
spiral.

LOGARITHMIC GROWTH OF THE HUMAN MANDIBLE.
Craniometric studies were performed
by fixing small lead shots affixed to
the Foramen Ovale ,Mandibular
foramen and Mental foramen of
mandibles at various stages of
dentition.The lateral x-rays of these
mandibles effectively outlined the
pathway of the Inferior alveolar
nerve.Consequently ,it is possible to
generate the curve representing
human mandibular growth at any
time.

The logarithmic spiral
formulated by Moss which
coincides with the three
foramena of the inferior
alveolar nerve and which
describes the path of
mandibular growth.
As the foramena separate
during growth, the mandible
continually assumes a
position where there is a
less curvature of the
spiral.Because the mandible
does not grow up and out
the rotation of the spiral
must occur.

ARCIAL GROWTH OF MANDIBLE
A normal human mandible grows by superior- anterior apposition at
the ramus on a curve or arc which is a segment formed from a
circle.The radius of this circle is determined by using the distance
from the mental protuberance ( Pm) to a point at the forking of the
stress lines at the terminus of the oblique ridge on the medial side of
the ramus (Point Eva)
According to Ricketts ,each individual
generates his own unique arc.3 curves
were ultimately drawn:
CURVE A – Passes through DC -Xi
and Pm .
CURVE B - Passes through tip of the
coronoid process and Pm.
CURVE C – Passes through point Eva
and Pm .
Curve C best fits the Arcial
growth of mandible.www.indiandentalacademy.com

Point Eva ,the confluence of
stress lines on the medial
surface of the ramus.
The curve created through
Eva and Pm with Tr as
centre represents the arc
of mandibular growth.
RICKETTS PREDICTION: The annual increase of
2.5mm when averaged over the years of time.Growth was
found to cease at 14.5 years for females and 19 for
males .This method, now , represents a convenient and
fairly reliable method for mandibular growth prediction.

METHODS OF GROWTH
PREDICTION
 CEPHALOMETRIC METHOD.
• METRIC.
• LONGITUDINAL.
• STRUCTURAL.
 CARTESIAN COORDINATE SYSTEM
MESH DIAGRAM.
 COMPUTERISED METHOD

LONGITUDINAL APPROACH
•The individual may be evaluated over a specified period to determine the
pattern of growth.
•Clinically applied by Tweed on his growing patients.
•He advocated taking two lateral cephalograms 12 to 18 months apart to
evaluate the skeletal facial changes.
•Consequently, the patient was placed into one of three categories
that are used to predict future growth trends.
TYPE A: The growth of middle and lower face proceeds in unison with changes
in the vertical and horizontal dimensions being approximately equal.
TYPE B: The middle face grows downward and forward more rapidly than the
lower face - growth predominantly in a vertical direction.
TYPE C: The lower face develops at a faster rate than the middle face.

LIMITATION OF LONGITUDINAL APPROACH
• Tweed’s basic assumption was that the growth pattern would remain
constant. Moore and other investigators and clinicians concluded that this
constancy can only be observed with population averages but not useful to
predict growth changes in a single individual.
• It is accurate only when it is performed retrospectively but not
prospectively.
• The pattern and rate of growth in one period is not similar to that
occurring in a subsequent period in any given individual.
•Hence , it is concluded that longitudinal approach is not an accurate
method.

METRIC METHOD
•Measuring different structures on a single x-ray film and then relating
these measurements to future growth changes.
•From a clinical perspective, it predicts how strong is the interrelationship
of the changes within a facial structure, between the various facial
structures and between the various facial structures and other body
dimensions.
•At this juncture ,it might be helpful to explain the scientific
determination and clinical application of the strength of the relationships
between any two variables.
•A correlation coefficient symbolized by a “r” describes the association or
the strength of the relationship between two variables
•A correlation coefficient also gives the direction , positive or negative , of
this relationship . It’s use in prediction is derived from squaring the value
of “r”, which is called the coefficient of determination.
•This coefficient describes the amount of variation of the second variable
that can be eliminated if the first variable is known.

•According to Horwitz and Hixon, a correlation coefficient may be statistically
significant at the 0.001 level of confidence but is still of no clinical significance for
prediction.
•As a rule they suggested an “r” value of 0.8 to be the dividing line for use in
clinical prediction because the coefficient of determination is 0.64.
•That is 64% of the variation can be accounted for in the variable that is being
predicted.
•It is with these facts in mind that the available data are interpreted.
LIMITATION OF METRIC METHOD.
•In independent studies by Bjork et al., correlation coefficiencies for facial
dimensions, be it linear or angular, when related to future growth of that same
dimension did not exceed an “r” of 0.4 or 0.5.
•This explains only 16% to 25% of the variation.
•This is still a fairly low correlation for clinical use.
•Hence this method is of less clinical application.

STRUCTURAL METHOD
•The structural method for predicting mandibular growth direction was
developed by Bjork from superimpositions on metallic implants.
•The method consists of reorganizing specific structural features in the
mandible that indicate future growth trends.
•When evaluating mandibular morphology, Bjork listed seven areas on
the cephalogram that should be evaluated to help predict future
mandibular growth direction.
1.The inclination of the condyle as an indication of it’s growth direction, whether
vertically or sagitally.For example, with vertical condylar growth, the mandible
rotates forward.
2.The curvature of the mandibular canal .The more curved the canal is, the more
forward the mandibular rotation will be.
3. Inclination of the symphysis.If it is inclined lingually, the mandible rotates
forward.
4.Shape of the lower border of the mandible.
5.The interincisal angle which is more acute in forward rotators.
6.The interpremolar or molar angles are also more acute in forward rotators.
7.Anterior lower face height

•The future direction of mandibular growth is influenced by the changes in
other parts of the craniofacial complex other than Bjork’s seven landmarks.
•These variables are difficult to quantify by any prediction method because
they are essentially unknown to both the clinician and the patient.
The longitudinal,metric and structural methods of prediction are of a
limited clinical value .
Recent computer technology has provided more sophisticated
approaches to this ongoing problem.
LIMITATION OF STRUCTURAL METHOD

CARTESIAN COORDINATE SYSTEM
MESH DIAGRAM
The study of proportional changes in the location of landmarks based on
upper facial height and face depth.
A mesh diagram is used to assess the facial morphology.

•A mesh diagram is constructed
by first drawing a core rectangle
oriented on the extracranial
vertical and scaled on upper face
height (nasion to ANS) and the
length of anterior skull
base(Nasion to sella).
By dividing the size of the core
grid rectangle into 2 equal parts,
distances for additional horizontal
and vertical grid lines are
obtained to complete the diagram.
•The face is thereby inscribed in a
rectilinear coordinate system
composed of 24 small rectangles.www.indiandentalacademy.com

The size increases between 8 and 16 years with median increments of
4.5 mm in boys and 3.5 mm in girls for a height and smaller
increments for length namely 3.2mm and 2.4mm for boys and girls
respectively.

COMPUTERISED PREDICTION METHODS
•Computerization is a tool of analysis rather than a method of analysis.
•This is because computers are programmed to use equations based on
either the longitudinal ,metric,structural,or other method of prediction.
•The biggest advantage of computer technology is that it facilitates
testing and applying more complex formulae to growth prediction.
.

Development of the computerised growth
forecasting.
•Brodie described the direction of growth of the various components of the
craniofacial complex through his cephalometric studies.
•Baumrind ,Korn and West conducted a study in attempt to predict the direction
of mandibular growth in 164 class II mixed dentition subjects and the results
clearly show the inability to differentiate the potential forward rotators from
potential backward rotators and hence concluded this method is unreliable.
•Ricketts –Arcial method of growth prediction
•Schulhof and Bagha—utilised the science of Biomathematics to computerize
growth and development.

•Johnston-use of “printed forecast grid”.
•Popovich- craniofacial templates based on individual age,sex and growth
patterns.
•Ricketts—the original version of rocky mountain data systems
•Christi: facial print.he compared profile to a fingerprint.
Recent Computer software systems for growth prediction:
 Quick Ceph for Apple Mackintosh
 Rocky mountain data systems for IBM
mainframe systems.
 Facial print- for IBM personal computer

LIMITATION
“ To err is human ; to really foul things up requires a poorly
programmed computer.”
This is not intended to mean that the clinicians should not use the
various computer programs available,but they need to realize that
such programs are useful for general patient education as well as
average growth or treatment simulations and not for individualized
predictions.

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.

CRANIAL BASE PREDICTION
The cranial base is designated by a line joining the most anterior point of
the Foramen Magnum with the Nasion as seen on the lateral
cephalometric radiograph.
PREDICTION: In normal patient,the
cranial base will grow 2mm per year
during the active growth period.This is
expressed as 1mm of forward growth
of Nasion and 1mm of backward
growth of Basion,both along the
original cranial baselength.

MANDIBULAR GROWTH PREDICTION
CONDYLAR AXIS:The axis of the condyle is defined as
a line from a point on the Ba-N Line midway between the
anterior and posterior borders at the condylar neck (DC
POINT) to the geometric centre of the mandibular ramus.
CORPUS AXIS: The length of the body of the mandible is
defined by a line from Xi point to the anterior point on the
mandibular symphysis.
PREDICTION: Condylar
axis grows 1mm per year.
Corpus axis grows 2mm per
year.

MANDIBULAR GROWTH PREDICTION
MANDIBULAR ARC: The angle formed by the condylar
and corpus axis describes the configuration of the mandible.
PREDICTION: A small angle
is indicative of steep
mandibular plane associated
with a vertically growing
mandible..
A larger than normal angle is
correlated with a square
mandible associated with more
favourable forward mandibular
growth.

MAXILLARY GROWTH PREDICTION
Nasion and point A grow forward same
amount each year. The angle formed by
intersection of N-A and Frankfurt horizontal
thus remains same during normal growth.
Skeletal convexity is determined
by relation between A point and
facial plane.If A is in front of
plane ,skeleton is said to be
convex.
The clinician must realize the effects of orthopedic appliances
on the maxilla and more specifically on the A point..www.indiandentalacademy.com

DENTITION
Once the position of the mandible and maxilla is
determined , a line is drawn between A point and
Po .The incisor teeth are then related to the A-Po
line.
LOWER INCISOR
The mandibular incisor usually stays in a constant
relationship to the A-Po line throughout the growth.
In ideal situation,the incisal edge is 1mm ahead of the
A-Po line.
SIGNIFICANCE: Any anterior or posterior
movement of the lower incisor has a two-fold effect
on the arch length of the dentition.If the lower incisor
is moved back 1mm, the arch length is decreased by
2mm.

UPPER INCISOR
The maxillary incisor also remains constant to
the A-Po line.
The incisal edge of the upper incisor is 3.5 mm
to the A-Po line.
INTERINCISAL RELATIONSHIP
This remains the same during growth.The
normal angle is 130º.
The upper incisor should be 28º and the lower
incisor 22º to the A-Po line.
.
MOLAR RELATIONSHIP
Position of molars is determined by ideal incisor position
and consequent archlength discrepancy.The upper molar is
3mm distal to it’s lower counterpartwww.indiandentalacademy.com

TREATMENT ALTERATIONS
Once the clinician understands the changes that occur with
normal growth,it is just as important to be aware of the
alterations that can occur with various treatment systems.
MANDIBULAR CHANGES
The facial axis is the line between the Pt-point
and the cephalometric Gnathion.This angle
remains stable during growth and any changes
would be due to clinicians
mechanotherapy.During treatment,the changes
that can occur are,
Convexity reduction -1˚/ 5mm of change
Molar correction -1˚/ 3mm of change
Overbite correction -1˚/ 4mm of change
Crossbite correction -1˚to –1.5˚

MAXILLARY CHANGES
Nasion and A point on the maxilla grow forward and equal amount per
year.Any angle that relates these 2 points to each other does not
change with normal growth .
A list of mechanics and their effect on the antero-posterior position of
point A of the maxilla as it relates to the vertical facial plane(N-Pog):
Cervical headgear -8mm
Class II elastics -3mm
Activator -2mm
Lingual root torque of 1 -2mm
Class III elastics +3mm
Clinically, the palatal plane (ANS –PNS) rotates in a clockwise
direction as the forces produced by the appliance affect the
midface region. A point will not only move distally but also drop
inferiorly half the distance.

GENETIC APPROACH
Another approach to growth prediction has been from a
genetic viewpoint using a comparison of family likeliness
in siblings and other relations together with suitable
formulae to predict the facial type.
This worked well in predicting the lower jaw size of a
member of THE HAPSBURG ROYAL FAMILY who
were famous for their characteristically large lower
jaw.

JOURNAL REVIEW

AN INSTRUMENT FOR ANALYSIS OF FACIAL
GROWTH (AJO 1969 )
• An instrument was
designed to identify ,
measure and demonstrate
the nature of complex
morphologic
interrelationships and
growth interactions that
exist among separate bones
during the remodelling
process
INSTRUMENT DESIGN

INSTRUMENT USES
• Identification and study of specific bones involved in
growth changes
• By manipulation of the instrument,dependent growth
changes may be precisely located and measured for any
given amount of cranial base elongation
• Dimensions in head film – accurately duplicated
• - Growth changes as observed in serial films may be
made and growth history may be reconstructed
• - predicted extent of growth in a given plane estimated
by providing desired amount of growth in other selected
segments and then adjusting the instrument on balance and
fit between all the dimension

A SIMPLIFIED APPROACH TO PREDICTION ( AJO
1975 )
• Purpose of the article – to present a simple
alternative based on the mean increments by direct
superimposition on a printed grid

FRONTAL SINUS & MANDIBULAR GROWTH
PREDICTION(AJO DO 1991 DEC)
•Rassouw,Lombard & Harris
•Correlation between max & mand length, symphysis width,condylar
length & frontal sinus on lateral ceph
•Frontal sinus bud present at birth in ethmoid region
•Rapid growth to adult size at 12 years
•Tunner-Annual height growth increments reached a plataeu at ages
when frontal sinus enlargement ceased
•Brown,Molleson & Chinn – study on lateral ceph
•The surface area(sq.mm) of frontal sinus –assessed by summagraphic
decoder linked to a microcomputer
•Negative ANB angle – small maxilla & large mandible coincided with large
frontal sinus
•Frontal sinus size though influenced by external environment & muscle
attachments is a valuable indicator of excessive mandibular growth.

ANTEGONIAL NOTCH FOR GROWTH
PREDICTION(AJO DO 1992 )
•Singer , Mamandras & Hunter
•Presence of prominent antegonial notch-arrested growth of
mandibular condyles
Apposition Resorption
Forward rotating symphysis Angle
Backward rotating Angle Symphysis
So deep antegonial notch – Backward rotating mandible.

Growth prediction from posture - Solow and
Siersbæk-Nielson AJO-DO 1992 May
 In this study of predictive
relationships, an association was found
between craniocervical angulation and
development of the lower face.
Children with a large craniocervical
angle and an upright position of the
upper cervical column displayed a
more vertical subsequent facial growth
pattern , than children with a small
craniocervical angulation and a
backward inclination of the upper
cervical column.

 This is in agreement with a prediction by the soft tissue stretching
hypothesis presented by Solow and Kreiborg.According to this
hypothetical model, obstruction of the upper airways can lead to an
increase in the craniocervical angulation to facilitate respiration.
 This leads to a stretching of the soft tissue layer covering the face
and throat, and the backward and downward components of the strain
in the soft tissue layer restricts or redirects the forward component of
facial development in a more caudal direction.
 While the earlier studies indicated the presence of some biologic
mechanism coordinating changes in posture and lower facial development
but did not indicate the direction of the cause-and-effect relationship, that
is, whether posture influenced structure or vice versa, this study suggests
that posture or factors determining posture do seem to influence the
direction of growth of the face.

FORECASTING AND MONITORING FACIAL
GROWTH - MEW (AJO-DO AUG 1993 )
• Forward growing faces are often referred to as "low angle"
cases, and downward growing as "high angle" because of
the difference in the mandibular angle. Low angle cases
generally have more facial appeal than high angle, and the
cheek line tends to run more parallel with the nose,
although the indicator line may be increased if there is a
deep bite. Although downward growers may look
attractive while in the deciduous dentition, "growing up"
can be associated with some unflattering developments.
• Obviously, it would be of considerable value if such
changes could be anticipated.

• The indicator line uses the
diagonal coordinate by measuring
from the tip of the nose to the tip of
the upper left central incisor .
• The indicator line can prove very
helpful both in assessing
downward growth and establishing
clinical objectives.
The indicator line

This can be assessed by marking the skin
1 cm below the center of the lower eyelid
in the sagittal plane. The line between
these points is called the cheek line and
ideally should run parallel to the surface
of the upper third of the nose, but more
normally it forms an angle of between
20° and 40°
The cheek line
The lower indicator line measures the
distance from the tip of the lower left
central incisor to the pogonion, for this
purpose the point on the chin farthest from
the tragus when the mentalis is relaxed
The lower indicator line

• Measurements taken from the indicator line, the cheek
line, and the lower indicator line will give a reasonable
indication of the appeal of the facial skeleton
• whenever the face is growing downwards, the indicator line will
be increased, and vice versa.

PREDICTION OF MANDIBULAR GROWTH
ROTATION(AJO DO DEC 1998)
• Magnitude and direction of mandibular growth markedly impact
orthodontic therapy in growing patients.
• Traditionally, it has been demonstrated that the mandible grows in a
downward and forward direction via posterior growth and anterior
displacement. However, it has also been shown to rotate over the course
of growth.
• This rotational aspect of mandibular growth can greatly influence the
therapeutic result of orthodontic treatment. In fact, a backward rotation of
the mandible is quite often regarded as being particularly difficult to treat.
Close observation is often required throughout the course of therapy to
deal with effects of the rotational pattern.
• The ability of an orthodontist to predict future mandibular growth rotation
would greatly aid in diagnosis and treatment planning. Better therapeutic
decisions could be made regarding timing and length of treatment,
appliance selection, extraction pattern, and possible need for surgery.
Therapy could truly be tailored to the individual with the possibility of
optimal results in a shorter period of time.

• Skieller, Björk and Linde-Hansen proposed a method for
predicting future mandibular growth rotation from an
initial prepubertal lateral cephalogram
• four variables
• These included: mandibular inclination,
intermolar angle,
Shape of the lower border of the mandible,
Inclination of the symphysis.
• Regression equations were given based on these variables
that could be applied to an initial prepubertal lateral
cephalogram and were believed to predict future
mandibular growth rotation.

AN ACCURATE METHOD OF PREDICTING MANDIBULAR
GROWTH POTENTIAL BASED ON BONE MATURITY (AJO
DO 2001 )
Mandibular total length at the final stage can be accurately predicted by
• Ossification events of third middle phalanx and radius
• Growth prediction method
• Growth percentage method
• Multiple regression method
• growth chart method
- Bone age as a parameter was calculated by both Tanner –
Whitehouse2 method and CASMAS
Objective of the study was
 To present a prediction formula using skeletal maturity indicator
 To clarify which method is most accurate
- Growth potential and growth prediction method – most useful
predictors of mandibular growth potentials

CONCLUSION
Various methods of growth prediction have been suggested
ranging from the crudest form of clear acetate templates to the
more sophisticated computer databasing .Whichever the
approach,the prediction would be reasonable in ‘average
growers’ but not in ‘abnormal growers’, the patients in whom
the orthodontist may be more interested.
Hence, the orthodontist should obtain diagnostically useful
data that permit the interpretation of dental relationships at all
ages in terms of skeletal,soft tissue and prevailing
environmental factors responsible for the existing
occlusion.Only then will we be able to successfully predict the
future changes that nature will produce and make the necessary
adjustments through our intervention by treatment.www.indiandentalacademy.com

REFERENCES
• Growth Prediction—Ranley.
• Bioprogressive therapy– Ricketts.
• Computerized forecasting ---VTO--- Spiro j.Chaconas
• An instrument for analysis of facial growth – AO 1969
• Prediction of craniofacial growth:the state of the art – AJO Nov 1971
• A simplified approach to prediction – AJO 1975
• The prediction of facial growth – AO April 1980
• Growth prediction from posture - Solow and Siersbæk-Nielson AJO-DO May
1992
• Frontal sinus & mandibular growth prediction-AJO DO 1991 Dec
• Antegonial notch for growth prediction-AJO DO 1992
• Forecasting and monitoring facial growth - AJO-DO Aug 1993
• Prediction of mandibular growth rotation- AJO DO Dec 1998
• An accurate method of predicting s growth potential based on bone maturity
-AJO DO 2001 www.indiandentalacademy.com

THANK YOU

Growth prediction

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