Growth prediction 3

GROWTH PREDICTIONGROWTH PREDICTION
• IntroductionIntroduction
• DefinitionDefinition
• UsesUses
• MethodsMethods
• LimitationLimitation
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• Scammon’s curveScammon’s curve
• Cephalocaudal gradientCephalocaudal gradient
• Data from various studiesData from various studies
Bolton brush studyBolton brush study
Iowa growth studyIowa growth study

DefinitionDefinition
• Assumption of ability to estimateAssumption of ability to estimate
practically future growth.practically future growth.
• Asserting on the basis of theory, data orAsserting on the basis of theory, data or
experience but in advance of proof.experience but in advance of proof.

Why it is necessary ?Why it is necessary ?
• Helps in diagnosisHelps in diagnosis
• Development of satisfactory treatmentDevelopment of satisfactory treatment
planplan

Growth predictionGrowth prediction
Methods of predicting facial growth changeMethods of predicting facial growth change
 According BjorkAccording Bjork
 Computerized prediction methodsComputerized prediction methods
 Logarithmic spiralLogarithmic spiral
 Arcial growth of the mandibleArcial growth of the mandible
 Visual treatment objectiveVisual treatment objective
• Jacobson and SadowskyJacobson and Sadowsky
• RickettsRicketts
• HoldwaysHoldways

According BjorkAccording Bjork
• Longitudinal approachLongitudinal approach
• Metric approachMetric approach
• Structural approachStructural approach

• Longitudinal approachLongitudinal approach
- Tweed on growing pt.Tweed on growing pt.
- 2 lateral ceph. 12-18 months apart2 lateral ceph. 12-18 months apart
- 3 categories Type A3 categories Type A
Type BType B
Type CType C

type A – middle & lower face growth intype A – middle & lower face growth in
unison + equal change in vertical &unison + equal change in vertical &
horizontal dime.horizontal dime.
Type B – middle face > lower faceType B – middle face > lower face
Type C – lower face < middle faceType C – lower face < middle face

Tweed – growth pattern remain constant.Tweed – growth pattern remain constant.
- Moore et al- Moore et al
- No use in predicting changes.- No use in predicting changes.
• LimitationLimitation
Accurate in Retrospective.Accurate in Retrospective.
• Conclusion –Conclusion –
Not accurate method.Not accurate method.

• Metric approachMetric approach
- consist of measuring different structure on a single- consist of measuring different structure on a single
radiograph & then relating these measurement toradiograph & then relating these measurement to
future growth changes .future growth changes .
Correlation coefficient =rCorrelation coefficient =r
- Association b/w 2 variableAssociation b/w 2 variable
- Direction either positive or negative of theDirection either positive or negative of the
relationshiprelationship
- It is used in prediction by -It is used in prediction by -
Squaring the value of ‘r’ = coefficient of determinationSquaring the value of ‘r’ = coefficient of determination
( amount of variation of 2( amount of variation of 2ndnd
variable )variable )www.indiandentalacademy.comwww.indiandentalacademy.com

• Bjork ,Harvold ,Lande, Solow ,othersBjork ,Harvold ,Lande, Solow ,others
- Correlation Coefficient not more 0.4 or 0.5Correlation Coefficient not more 0.4 or 0.5
- 16% to 25% variation16% to 25% variation
ConclusionConclusion
this methods is least clinically siginificantthis methods is least clinically siginificant

• Structural approachStructural approach
-- To predict mandible growthTo predict mandible growth
directiondirection
-- Superimposition onSuperimposition on
metallic implantmetallic implant
- 7 areas- 7 areas
1.1. Inclination of condyleInclination of condyle
2.2. Curvature of theCurvature of the
mandibular canalmandibular canal
3.3. Inclination of symphysisInclination of symphysis

4.4. Shape lower border ofShape lower border of
the mandiblethe mandible
5.5. The interincisal angleThe interincisal angle
6.6. The interpremolar orThe interpremolar or
molar anglemolar angle
7.7. The anterior lower facialThe anterior lower facial
heightheight
ConclusionConclusion
This is also least clinicallyThis is also least clinically
siginificantsiginificant

• Skeiller ,Bjork, and Linde – HansenSkeiller ,Bjork, and Linde – Hansen
(Tried to quantify it)(Tried to quantify it)
• 4 variable4 variable
1.1. MP inclination - Anterior cranial base (MP:SN)MP inclination - Anterior cranial base (MP:SN)
or Ratio of posterior & anterior facial heightor Ratio of posterior & anterior facial height
2.2. The intermolar angleThe intermolar angle
3.3. Shape of lower border of the mandibleShape of lower border of the mandible
(GO - ME to lower border of the mandible)(GO - ME to lower border of the mandible)
4.4. Symphysis inclination (sym. Anterior surface –SN)Symphysis inclination (sym. Anterior surface –SN)

• Measurement of these variables wereMeasurement of these variables were
includedincluded
R squar = 0.8612 = 86% variation in direction ofR squar = 0.8612 = 86% variation in direction of
mandibular growthmandibular growth
• But 86% was high valueBut 86% was high value

 According BjorkAccording Bjork
 Computerized prediction methodsComputerized prediction methods
 Logarithmic spiralLogarithmic spiral
 Arcial growth of the mandibleArcial growth of the mandible
 Visual treatment objectVisual treatment object

• Computerized prediction methodsComputerized prediction methods
• Tool of analysis not a methodTool of analysis not a method
• AdvantageAdvantage
1.1. Facilitates testingFacilitates testing
2.2. Complex formulas to growth predictionComplex formulas to growth prediction

• Ricketts 1970 – potential of computerizationRicketts 1970 – potential of computerization
- Cephalogram (diagnosis ,T/P)Cephalogram (diagnosis ,T/P)
• Greenberg & JohnstonGreenberg & Johnston
- Computer forecasts not better than the- Computer forecasts not better than the
assumption of average growthassumption of average growth
- No difference bet. this & method based on- No difference bet. this & method based on
simple addition of the average changes.simple addition of the average changes.

Computerized prediction methodsComputerized prediction methods
Logarithmic spiralLogarithmic spiral
Arcial growth of the mandibleArcial growth of the mandible
Visual treatment objectVisual treatment object

• Logarithmic spiralLogarithmic spiral
Golden trianglesGolden triangles
WhyWhy
 how the position of 3 foramina on thehow the position of 3 foramina on the
unitary , logarithmic spiral in anterior openunitary , logarithmic spiral in anterior open
bite and deep bite pt. (Melvin. Moss )bite and deep bite pt. (Melvin. Moss )

Logarithmic spiralLogarithmic spiral

Evolution of logarithmic spiralEvolution of logarithmic spiral
• Sectioning of a lineSectioning of a line
• Smaller section is proportional to large sectionSmaller section is proportional to large section
• Larger portion is called ‘golden section’Larger portion is called ‘golden section’
• Larger section is Phi /Larger section is Phi /

• Small section is 1Small section is 1
• Larger = 1.618 timesLarger = 1.618 times
the smallerthe smaller
• The smaller is 0.618The smaller is 0.618
the length of thethe length of the
largerlarger

• Phi relationshipPhi relationship
- Plants, animals, human body , face- Plants, animals, human body , face
• Golden progression – series of theseGolden progression – series of these
proportionsproportions
- Symbols -- Symbols -
22
,,
33
,,
44

• Golden triangleGolden triangle
• Base of a triangle 1.0Base of a triangle 1.0
• Sides of equilateralSides of equilateral
triangle 1.618triangle 1.618
• Forms a 72 – 72 -36Forms a 72 – 72 -36
degreedegree

• Bisection of one baseBisection of one base
angle cross the oppositeangle cross the opposite
sideside
• Divide that side into aDivide that side into a
golden sectiongolden section
• Form new goldenForm new golden
triangletriangle

• Bisection of golden triangle can be made in a seriesBisection of golden triangle can be made in a series

• Curve used to connectCurve used to connect
the points on a series ofthe points on a series of
the trianglesthe triangles
• Form Logarithmic spiral.Form Logarithmic spiral.

• So human mandibleSo human mandible
grows as a logarithmicgrows as a logarithmic
spiral on the arc.spiral on the arc.

Melvin MossMelvin Moss
• Aim - determine the position of 3 foramina on theAim - determine the position of 3 foramina on the
unitary , logarithmic spiral in anterior open bite andunitary , logarithmic spiral in anterior open bite and
deep bite pt.deep bite pt.
• These conditions can be anticipated at young ageThese conditions can be anticipated at young age
even before orthodontic diagnosiseven before orthodontic diagnosis
• ForamenForamen
1.1. Foramen ovaleForamen ovale
2.2. Mandibular foramen inferior alveolar nerveMandibular foramen inferior alveolar nerve
3.3. Mental foramenMental foramen

Studied the position of the inferior alveolarStudied the position of the inferior alveolar
nervenerve
• ConclusionConclusion
These foramina , at all ages fit preciselyThese foramina , at all ages fit precisely
upon a single mathematically definedupon a single mathematically defined
logarithmic spirallogarithmic spiral

Foramen “moved” downForamen “moved” down
along this samealong this same
logarithmic spiral inlogarithmic spiral in
geometric fashiongeometric fashion
The gradient of motionThe gradient of motion
directly increasing with thedirectly increasing with the
distance of the foraminadistance of the foramina
from cranial base.from cranial base.

• Method and materialsMethod and materials
2 group of pt.2 group of pt.
Columbia university University of utahColumbia university University of utah
16 pt - 3 m & 4 f 4 groups (Ant16 pt - 3 m & 4 f 4 groups (Ant
Open bite) 10 pt Normal swallowersOpen bite) 10 pt Normal swallowers
- 4 m & 5 f 10 pt Tongue thrust- 4 m & 5 f 10 pt Tongue thrust
(Deep bite) 5 pt Angle II div 1(Deep bite) 5 pt Angle II div 1
5 pt Ant open bite5 pt Ant open bite

• Tracing of cranial base & mandibular outlineTracing of cranial base & mandibular outline
from filmsfrom films
• Superimposed the logarithmic spiralSuperimposed the logarithmic spiral
• Position of 3 foramen marked on it.Position of 3 foramen marked on it.

• ResultResult
 Singular position ofSingular position of
foramen ovale inforamen ovale in
anterior open bite.anterior open bite.
 Foramen ovale locatedForamen ovale located
farther down the spiral.farther down the spiral.
Help in diagnosisHelp in diagnosis
 No sexual dimorphismNo sexual dimorphism

 Mandibular & mentalMandibular & mental
foramen also furtherforamen also further
down the logarithmicdown the logarithmic
spiral in AOBspiral in AOB
 Not as diagnosticallyNot as diagnostically
uniqueunique
 Distance betweenDistance between
these not decreased.these not decreased.

 Foramen oval clusterForamen oval cluster
relatively ‘high’ up onrelatively ‘high’ up on
the spiral in deep bite.the spiral in deep bite.

DiscussionDiscussion
Mandibular shapeMandibular shape - inferior alveolar nerveinferior alveolar nerve
- 2 factors foramina position on the spiral- 2 factors foramina position on the spiral
distance between them.distance between them.
• Fetal & circumnatal periodsFetal & circumnatal periods
- All foramina placed near the origin of spiral and- All foramina placed near the origin of spiral and
nearer to each othernearer to each other
- Flatter curvature- Flatter curvature
- Mandible gonial angle relatively obtuse or flat.- Mandible gonial angle relatively obtuse or flat.

With growth , all foramina moved down alongWith growth , all foramina moved down along
the spiral and distancethe spiral and distance
• Ramus becomes more erect relatively toRamus becomes more erect relatively to
corpuscorpus
• Gonial angle becomes acuteGonial angle becomes acute

• Anterior open biteAnterior open bite
 Foramen ovale downForamen ovale down
along the spiralalong the spiral
Distance mand. &mentalDistance mand. &mental
foramen not decreaseforamen not decrease
Course of inferior alveolarCourse of inferior alveolar
nerve flatternerve flatter
 Ramus & corpus moreRamus & corpus more
obutseobutse www.indiandentalacademy.comwww.indiandentalacademy.com

• Deep biteDeep bite
‘‘Higher’ up on the spiralHigher’ up on the spiral
 3 neural foramina3 neural foramina
distance not decreaseddistance not decreased
 Inferior alveolar nerveInferior alveolar nerve
curvilinear coursecurvilinear course
 Ramus & corpus moreRamus & corpus more
acuteacute

• Anterior cranial base – RichardsonAnterior cranial base – Richardson
Sella - NASella - NA
Deep biteDeep bite
AnteriorAnterior
open biteopen bite

Anterior open bite Deep biteAnterior open bite Deep bite
• Gonial angleGonial angle
Ar –Go-Me Obtuse AcuteAr –Go-Me Obtuse Acute
• Mandibular sizeMandibular size
Ramus Shorter No significantRamus Shorter No significant
Corpus Normal length linear differenceCorpus Normal length linear difference
• Anterior cranial baseAnterior cranial base
(S-Na) No difference(S-Na) No difference

Anterior open bite Deep biteAnterior open bite Deep bite
• Periosteal functional matrixPeriosteal functional matrix
(Massater) No difference in attachment site(Massater) No difference in attachment site
• Capsular functional matrixCapsular functional matrix
Oral functioning spaceOral functioning space
Abnormal NormalAbnormal Normal

Visual treatment objectiveVisual treatment objective

Principal of Arcial growth of thePrincipal of Arcial growth of the
mandiblemandible
Robert M. RickettsRobert M. Ricketts
• PurposePurpose – explain a method for finding the arcial– explain a method for finding the arcial
growth of the mandible and to enumerate some uses ofgrowth of the mandible and to enumerate some uses of
the principalthe principal
• Based on computer studyBased on computer study
• Predict long range growth forecastPredict long range growth forecast

Arcial growth of the mandibleArcial growth of the mandible
• PrincipalPrincipal – mandible grows by superior-– mandible grows by superior-
anterior apposition at the ramus on aanterior apposition at the ramus on a
curve or arc which is a segment formedcurve or arc which is a segment formed
from a circle.from a circle.
• Radius – Pm to point Eva.Radius – Pm to point Eva.

• Growth of the mandibleGrowth of the mandible
1.1. Roentgenographic cephalometricRoentgenographic cephalometric
2.2. BjorkBjork
3.3. EnlowEnlow
BjorkBjork
- variation in the mandibular bending.variation in the mandibular bending.
- Resorption of lower angular borderResorption of lower angular border
- 33rdrd
molar crypt – stable longitudinal referencemolar crypt – stable longitudinal reference
EnlowEnlow
3D growth pattern Remodeling area3D growth pattern Remodeling area
Reversal areas of stabilityReversal areas of stabilitywww.indiandentalacademy.comwww.indiandentalacademy.com

Prediction of mandibular growthPrediction of mandibular growth
• Primary methodsPrimary methods
- Long axis of condyle & neck- Long axis of condyle & neck
- Lower border of mandible- Lower border of mandible
• ‘‘Central core’ cephalomertricallyCentral core’ cephalomertrically
• Search for ‘reference point’Search for ‘reference point’
• External mandible (mandibular plane,ramus plane,External mandible (mandibular plane,ramus plane,
condyle – symphysis )condyle – symphysis )

• Xi pointXi point – center of– center of
ramusramus
Occlusal planeOcclusal plane
Entrance of neurotrophicEntrance of neurotrophic
bundlesbundles

• Bisect the height of ramus from theBisect the height of ramus from the
sigmoid notchsigmoid notch

• Dc pointDc point
• Condyle axisCondyle axis
• Corpus axisCorpus axis
• Change in angle - changeChange in angle - change
in mandibular formin mandibular form
• Second methodSecond method ––
Magnitude & angularMagnitude & angular
relation.relation.
• More successful as aMore successful as a
method of forecastingmethod of forecasting

• Suprapogonion / PmSuprapogonion / Pm
Reference pointReference point
Ricketts – stress centerRicketts – stress center
Enlow – site of reversalEnlow – site of reversal
lineline
Bjork - cosistentBjork - cosistent

• The objective of research was still towardsThe objective of research was still towards
finding a method to critically predict futurefinding a method to critically predict future
form and size of the mandible over theform and size of the mandible over the
long range.long range.

computer studycomputer study
• 5 yrs growth study of mandible & lower5 yrs growth study of mandible & lower
dental archdental arch
• In lateral & frontal head films -362In lateral & frontal head films -362
measurementmeasurement

MaterialMaterial
• 40 pt – lateral & frontal cephalometric film40 pt – lateral & frontal cephalometric film
• One group – 8 yrs another group -13 yrsOne group – 8 yrs another group -13 yrs
• No orth. t/tNo orth. t/t
• 20M & 20F20M & 20F
• 20 – class I with normal occlusion20 – class I with normal occlusion
• 20 - class II malocclusion20 - class II malocclusion

FindingsFindings
• Mandible bend ½Mandible bend ½
degree per year.degree per year.
• Bending in an orderlyBending in an orderly
manner.manner.
• Growth arc wasGrowth arc was
operative.operative.

• First arc – Pm ,Xi ,DcFirst arc – Pm ,Xi ,Dc
• Straightening of theStraightening of the
mandiblemandible
• To determine the true arc of growth of theTo determine the true arc of growth of the
mandiblemandible

• Second arcSecond arc - tip of- tip of
coronoid , R1 , Pmcoronoid , R1 , Pm
• Segment of circle small inSegment of circle small in
radius.radius.
• Excessive bending ofExcessive bending of
mandiblemandible

• True arcTrue arc – Condylar &– Condylar &
Coronoid process ,Coronoid process ,
Ramus center & it’s ant.Ramus center & it’s ant.
BorderBorder
• Radius increase orRadius increase or
changing with the size ofchanging with the size of
the mandiblethe mandible
• Changing arc or ultimateChanging arc or ultimate
spiral would result.spiral would result.
• Growth could not beGrowth could not be
represented as simplerepresented as simple
segment of circlesegment of circle www.indiandentalacademy.comwww.indiandentalacademy.com

Stress linesStress lines
• 850 yrs. Old mandible –850 yrs. Old mandible –
William B. DownsWilliam B. Downs
• Disintegration ofDisintegration of
interprismatic subs.interprismatic subs.
• Stress lines in the outerStress lines in the outer
& inner plates& inner plates

• Examination ofExamination of
stress lines / lateralstress lines / lateral
surfacesurface
Convergence atConvergence at
protuberance mentiprotuberance menti
Upward ,backward &Upward ,backward &
outward from EOoutward from EO
Gnarled area at theGnarled area at the
coronoid base.coronoid base.

• Stress line /medial sideStress line /medial side
 Mylohyoid ridgeMylohyoid ridge
 YM /Y-shaped bonyYM /Y-shaped bony
prominenceprominence
- Center of quadrant of- Center of quadrant of
ramusramus
- Inner & outer cortical tables- Inner & outer cortical tables
showed confluenceshowed confluence
 TP/ Triangular plane –TP/ Triangular plane –
Nutritive foraminaNutritive foramina

• 2 new point2 new point - Eva &TR- Eva &TR
• EvaEva- forking of stress lines- forking of stress lines
in ramusin ramus
• TR /true radiusTR /true radius – center– center
of circle from Pog throughof circle from Pog through
EvaEva
• Mu pointMu point

• Mandible size increased,Mandible size increased,
increment added to theincrement added to the
arc at the sigmoid notch.arc at the sigmoid notch.
• Predicted mandible wasPredicted mandible was
almost absolutely correctalmost absolutely correct
in size and form whenin size and form when
compared with the finalcompared with the final
compositecomposite

• Mandible growthMandible growth
occurs on a arcoccurs on a arc
• This method provedThis method proved
extremely accurate inextremely accurate in
50 treated cases50 treated cases
which were predictedwhich were predicted
and compared forand compared for
periods of as long asperiods of as long as
14 yrs later.14 yrs later.

• Amount of growth toAmount of growth to
forecast on the arcforecast on the arc
- 2.5 yearly increase- 2.5 yearly increase
14.5 F & 19M14.5 F & 19M
• Symphysis lowerSymphysis lower
borderborder – 1mm each 8– 1mm each 8
yrs / Myrs / M

• Coronoid & condylarCoronoid & condylar
processprocess – different– different
• CoronoidCoronoid – 0.8mm/yr– 0.8mm/yr
• CondylarCondylar - variable- variable
1.1. Short & weak – 0.0mmShort & weak – 0.0mm
2.2. Long condyles –Long condyles –
0.4mm/yr0.4mm/yr
3.3. Average – 0.2mm /yrAverage – 0.2mm /yr

• Gonion angleGonion angle growthgrowth
50% of the total increase50% of the total increase
in mandibular growthin mandibular growth
• Females - no furtherFemales - no further
additionaddition
• Males – above +0.2mmMales – above +0.2mm

• External oblique ridgeExternal oblique ridge
0.4mm/yr.0.4mm/yr.
• RR point – stable boneRR point – stable bone
Ramal widthRamal width

• Impaction of third molar and ArcialImpaction of third molar and Arcial
growth prognosis –growth prognosis –25 adult skull25 adult skull
normal occlusionnormal occlusion
1.1. Lower third molar 50 % ahead the EORLower third molar 50 % ahead the EOR
50% favorable prognosis50% favorable prognosis
2.2. Mesial to the EOR – 100 % favorable prognosisMesial to the EOR – 100 % favorable prognosis
3.3. Distal to the EOR – poorerDistal to the EOR – poorer
45 % of the nonextracted cases required third molar45 % of the nonextracted cases required third molar
extraction.extraction.

• Bisect the height of ramus from theBisect the height of ramus from the
sigmoid notch down to the lower border insigmoid notch down to the lower border in
a perpendicular plane from FH ,thena perpendicular plane from FH ,then
bisected the width of the mandible calledbisected the width of the mandible called
XI pointXI point

• 2 new point2 new point - Eva &TR- Eva &TR
• EvaEva- forking of stress lines in- forking of stress lines in
ramusramus
• A center of upward & forwardA center of upward & forward
quadrant of ramusquadrant of ramus
• By bisecting R2 & R3 pointBy bisecting R2 & R3 point
• TR /true radiusTR /true radius – center of– center of
circle from Pog through Evacircle from Pog through Eva
• Mu pointMu point

• Class IIIClass III
The amount of mandibularThe amount of mandibular
growth in the forecast isgrowth in the forecast is
one sixth more in theone sixth more in the
classIIIclassIII

• May be occur inMay be occur in
closed bite facesclosed bite faces

Visualized treatment objectiveVisualized treatment objective

Visualized treatment objectiveVisualized treatment objective
• UsesUses

It is a visual plan to forecast the normalIt is a visual plan to forecast the normal
growth of the pt and the anticipated influencesgrowth of the pt and the anticipated influences
of treatment , to establish the individualof treatment , to establish the individual
objectives we want to achieve for that ptobjectives we want to achieve for that pt

• UsesUses
1.1. Predict growth over an estimated T/t timePredict growth over an estimated T/t time
2.2. Analyzes the soft tissue facial profileAnalyzes the soft tissue facial profile
3.3. Determines favourable incisor repositioningDetermines favourable incisor repositioning
based on an ‘ideal’ projected soft tissuebased on an ‘ideal’ projected soft tissue
profileprofile
4.4. Determines total arch length discrepancyDetermines total arch length discrepancy

5.5. Aids in determining b/w extraction &Aids in determining b/w extraction &
nonextraction treatmentnonextraction treatment
6.6. Surgical orthodontic correctionSurgical orthodontic correction

ALEX JACOBSON &ALEX JACOBSON &
P.LIONEL SADOWSKYP.LIONEL SADOWSKY
• All cephalometric headfilms to be taken in the lipsAll cephalometric headfilms to be taken in the lips
closed position even if they are strained to closeclosed position even if they are strained to close
• Construct a VTO by considering average growth forConstruct a VTO by considering average growth for
an estimated 2 yr period of active t/t & the objectivean estimated 2 yr period of active t/t & the objective
we want to achieve with our mechanicswe want to achieve with our mechanics

Cephalometric tracing for VTOCephalometric tracing for VTO
• Anterior & posterior cranial baseAnterior & posterior cranial base
• Pterygomaxillary fissurePterygomaxillary fissure
• OrbitOrbit
• Anterior outlines of frontal boneAnterior outlines of frontal bone
• Nasal bone & NasionNasal bone & Nasion
• ANS &PNS ,hard palateANS &PNS ,hard palate
• Upper central incisor & it’s alveolar processUpper central incisor & it’s alveolar process
• MandibleMandible
• External auditory meatusExternal auditory meatus
• Soft tissue profilesSoft tissue profiles
• Upper & lower molarUpper & lower molarwww.indiandentalacademy.comwww.indiandentalacademy.com

Cephalometric tracing for VTOCephalometric tracing for VTO
• BAN (Basion-nasion line)BAN (Basion-nasion line)
• Line Na - POINT ALine Na - POINT A
• F H PLANEF H PLANE
• Occlusal planeOcclusal plane
• Downs mandibular planeDowns mandibular plane
• Facial axisFacial axis
• Holdway’s lineHoldway’s line
• Facial planeFacial plane

Visual treatment objectiveVisual treatment objective
Step of VTOStep of VTO
• Step 1 obj. – To draw frontonasal area , BAN & NAStep 1 obj. – To draw frontonasal area , BAN & NA
line.line.
• StStep 2ep 2 obj. – Growth in frontonasal area over 2 yr.obj. – Growth in frontonasal area over 2 yr.
- Frontonasal area 1.5 mm growth- Frontonasal area 1.5 mm growth
- 1/4mm per year ( Dr. Holdway’s studies )- 1/4mm per year ( Dr. Holdway’s studies )

• Step 3 objectStep 3 object – Mandible growth in vertical direc.– Mandible growth in vertical direc.
- Ant. Portion of mandible- Ant. Portion of mandible
- Soft tissue chin- Soft tissue chin
- Down’s mandibular plane- Down’s mandibular plane
• Superimpose on the facial axisSuperimpose on the facial axis
• The distance b/w VTO & ceph Ban line should be 3The distance b/w VTO & ceph Ban line should be 3
times the amount of growth expressed previously intimes the amount of growth expressed previously in
FN areaFN area

Step 4 objStep 4 obj. – Mandible growth in horizontal. – Mandible growth in horizontal
direction.direction.
- Draw the Post border of mandible- Draw the Post border of mandible
• Forward growth at chin point = NasionForward growth at chin point = Nasion
• Total vertical facial height as well as forwardTotal vertical facial height as well as forward
location of chin establishedlocation of chin established

Step 5 objStep 5 obj. – To locate maxilla & lower half of nose. – To locate maxilla & lower half of nose
• Superimpose on NA line & move upSuperimpose on NA line & move up
• There is 40% of total vertical growth above BaN lineThere is 40% of total vertical growth above BaN line
& 60% below mandible& 60% below mandible
• Nose growth 1mm/year.Nose growth 1mm/year.
Step 6 obj.Step 6 obj. – To locate and draw the occlusal plane– To locate and draw the occlusal plane
• Superimpose on NA planeSuperimpose on NA plane
• Vertical growth is 50% above maxilla & 50% belowVertical growth is 50% above maxilla & 50% below
mandiblemandible www.indiandentalacademy.comwww.indiandentalacademy.com

Step 7 objStep 7 obj. – To determine soft tissue lip contour. – To determine soft tissue lip contour
using the new H-lineusing the new H-line
• The distance b/w upper lip contour & H-line isThe distance b/w upper lip contour & H-line is
3 - 7mm (Dr. Holdway’s studies )3 - 7mm (Dr. Holdway’s studies )

Step 8 objStep 8 obj. – To relocate the maxillary central incisor. – To relocate the maxillary central incisor
• Upper lip thickness = Basic upper lip thicknessUpper lip thickness = Basic upper lip thickness
( within 1 mm )( within 1 mm )
• Lip strain is difference b/w above measurementLip strain is difference b/w above measurement
• Maxillary incisor rebound - 0.5mm in class IMaxillary incisor rebound - 0.5mm in class I
- 1.5 mm in class II- 1.5 mm in class II
In this caseIn this case
Lip strain = 4 mmLip strain = 4 mm
Lip movement = 4 mmLip movement = 4 mm
Maxillary incisor rebound = 1.5 mmMaxillary incisor rebound = 1.5 mm
Total 9.5 mmTotal 9.5 mm

Step 9 obj.Step 9 obj. – To reposition lower incisor– To reposition lower incisor
- Calculate resultant arch length change- Calculate resultant arch length change
• Arch length change - measure the distance b/wArch length change - measure the distance b/w
old and new incisor position (2mm)old and new incisor position (2mm)
• Double the above distanceDouble the above distance
• Arch length change is in this case is 4 mmArch length change is in this case is 4 mm

Step 10 objStep 10 obj.. ––To reposition mandibular first molarTo reposition mandibular first molar
• Total arch length discrepancy = arch length lossTotal arch length discrepancy = arch length loss
+arch length discrepancy / model discrepancy+arch length discrepancy / model discrepancy
8 mm = 4 mm + 4mm8 mm = 4 mm + 4mm
• Extraction of 2Extraction of 2ndnd
PM on both side - 15 mm spacePM on both side - 15 mm space
Step 11 objStep 11 obj. – To reposition the maxillary first. – To reposition the maxillary first

A Soft - tissue cephalometricA Soft - tissue cephalometric
analysisanalysis
Reed A. HoldwayReed A. Holdway
• Based on soft - tissue measurementBased on soft - tissue measurement
VariationsVariations
• Sella nasion line is used express forward growthSella nasion line is used express forward growth
at nasionat nasion
• Growth on facial axis is 3mm/yr except duringGrowth on facial axis is 3mm/yr except during
growth spurtsgrowth spurts

analysisanalysis
• Head films should be taken with the pt’s lipHead films should be taken with the pt’s lip
touching positiontouching position

A Soft - tissue cephalometric analysisA Soft - tissue cephalometric analysis
Original tracing – 9 reference lineOriginal tracing – 9 reference line
• SN planeSN plane
• FH planeFH plane
• Occlusal planeOcclusal plane
• Nasion to Pog line (hard & soft tissue)Nasion to Pog line (hard & soft tissue)
• H- lineH- line
• Nasion to point A line / facial planeNasion to point A line / facial plane
• Facial axisFacial axis
• Down’s Mandibular planeDown’s Mandibular plane

Steps of VTO tracingSteps of VTO tracing
Step 1 – Draw Frontonasal areaStep 1 – Draw Frontonasal area
Sella – nasion lineSella – nasion line
Nasion- point A lineNasion- point A line

Step 2 - Express horizontal growth in the FNStep 2 - Express horizontal growth in the FN
area for the estimated T/tarea for the estimated T/t
• Growth at nasion is 0.66 to 0.75 mm/yrGrowth at nasion is 0.66 to 0.75 mm/yr
• Prediction of growth at nasion is an overallPrediction of growth at nasion is an overall
prediction for all midfacial structureprediction for all midfacial structure

Step 3Step 3 – Mandible growth in vertical dire.– Mandible growth in vertical dire.
• Growth on facial axis is 3 mm/yr except in growthGrowth on facial axis is 3 mm/yr except in growth
spurt periodspurt period
Step 4Step 4 – Mandible growth in horizontal dire.– Mandible growth in horizontal dire.
• At this point total vertical height has been forecastAt this point total vertical height has been forecast

Step 5Step 5 – To locate maxilla, the new point A &– To locate maxilla, the new point A &
lower half of noselower half of nose
• Vertical growth above the SN line & below theVertical growth above the SN line & below the
mandible is in ratio of 40 :60mandible is in ratio of 40 :60
• The vertical growth of the nose over 2 yr periodThe vertical growth of the nose over 2 yr period
keeps pace with the growth from the maxillakeeps pace with the growth from the maxilla
vertically to the anterior cranial basevertically to the anterior cranial base

Step 6 -Step 6 - locate and draw the occlusallocate and draw the occlusal
planeplane
• Vertical growth is 50% above maxilla & 50%Vertical growth is 50% above maxilla & 50%
below mandiblebelow mandible
• The occlusal plane is located 3 mm below the lipThe occlusal plane is located 3 mm below the lip
embrasureembrasure

Step 7Step 7 –– To determine soft tissue lip contourTo determine soft tissue lip contour
using the new H-lineusing the new H-line
• The distance b/w upper lip contour & H-line isThe distance b/w upper lip contour & H-line is
3 - 7mm3 - 7mm
• Short & thin lip – 3 mmShort & thin lip – 3 mm
• Long & thick lip – 5 mmLong & thick lip – 5 mm

Step 8Step 8 –– To relocate the maxillary centralTo relocate the maxillary central
incisorincisor
• Upper lip thickness = Basic upper lip thicknessUpper lip thickness = Basic upper lip thickness
( within 1 mm )( within 1 mm )
• Lip strain is difference b/w above measurementLip strain is difference b/w above measurement
• Maxillary incisor rebound - 0.5mm in class IMaxillary incisor rebound - 0.5mm in class I
- 1.5 mm in class II- 1.5 mm in class II

Step 9Step 9 – To reposition lower incisor– To reposition lower incisor
- Calculate resultant arch length change- Calculate resultant arch length change
• Arch length change - distance b/w old and newArch length change - distance b/w old and new
incisor positionincisor position
• Double the above distanceDouble the above distance
• Arch length change is in this case is 8 mmArch length change is in this case is 8 mm

analysisanalysis
Step 10Step 10 –– To reposition mandibular first molarTo reposition mandibular first molar
• Total arch length discrepancy = arch length changeTotal arch length discrepancy = arch length change
+arch length discrepancy / model discrepancy+arch length discrepancy / model discrepancy
10 mm = 8mm + 2mm10 mm = 8mm + 2mm
• Extraction of 2Extraction of 2ndnd
PM on both side - 15 mm spacePM on both side - 15 mm space
Step 11Step 11 – To reposition the maxillary first– To reposition the maxillary first

RICKETTSRICKETTS
Original tracingOriginal tracing
• NasionNasion
• ANSANS
• Point APoint A
• PMPM
• POGPOG
• CCCC
• BasionBasion
• DCDC
• XIXI

Construction of VTOConstruction of VTO
• Cranial base predictionCranial base prediction
• Mandibular growth predictionMandibular growth prediction
• Maxillary growth predictionMaxillary growth prediction
• Occlusal plane predictionOcclusal plane prediction
• The location of the dentitionThe location of the dentition
• The soft tissue of the faceThe soft tissue of the face

VTO –VTO – Cranial base predictionCranial base prediction
• Mark at CC pointMark at CC point
• Trace BaN PlaneTrace BaN Plane
• Nasion -1mm /yrNasion -1mm /yr
• Basion – 1 mm/yrBasion – 1 mm/yr

VTOVTO ––Mandibular growth predictionMandibular growth prediction
• Condylar axis growthCondylar axis growth
• Corpus axis growthCorpus axis growth
• Symphysis growthSymphysis growth

VTOVTO –– Mandibular growth prediction – RotationMandibular growth prediction – Rotation
• Mandible rotates open or closed from the effects ofMandible rotates open or closed from the effects of
mechanics used & the facial pattern presentmechanics used & the facial pattern present
• MechanicsMechanics
5 mm convexity reduction Facial axis open 1 degree5 mm convexity reduction Facial axis open 1 degree
4 mm overbite correction4 mm overbite correction
• Facial patternFacial pattern

VTO –VTO – Mandibular growth prediction – RotationMandibular growth prediction – Rotation
• Superimpose at BasionSuperimpose at Basion
• Rotate VTO tracing up to open the bite at nasion orRotate VTO tracing up to open the bite at nasion or
down to open the bitedown to open the bite
• This rotation depends on treatment effectThis rotation depends on treatment effect
• Trace condylar axis, coronoid & condylar processTrace condylar axis, coronoid & condylar process

VTO – Mandibular growth predictionVTO – Mandibular growth prediction
Condylar axis , Corpus axis growthCondylar axis , Corpus axis growth
• Condylar axis moves 1mm /yr down from DC pointCondylar axis moves 1mm /yr down from DC point
• PM moves forward 2mm /yr in normal growthPM moves forward 2mm /yr in normal growth
VTO – Mandibular growth prediction -SymphysisVTO – Mandibular growth prediction -Symphysis
growthgrowth
• Coincide old & new PMCoincide old & new PM
• Copy the symphysis , mandibular planeCopy the symphysis , mandibular plane
• Construct facial plane & facial axisConstruct facial plane & facial axiswww.indiandentalacademy.comwww.indiandentalacademy.com

VTO –VTO – Maxillary growth predictionMaxillary growth prediction
• Superimpose at nasion along the facial planeSuperimpose at nasion along the facial plane
• Divide the original & new menton into 3 part by usingDivide the original & new menton into 3 part by using
2 mark2 mark
• Superimpose mark 1 on original menton , copy theSuperimpose mark 1 on original menton , copy the
maxillamaxilla

VTO – Maxillary growth predictionVTO – Maxillary growth prediction
Point A change related to BA – NAPoint A change related to BA – NA
• Position of Point A change with growth & different mechanicsPosition of Point A change with growth & different mechanics
Mechanics Maximum rangeMechanics Maximum range
1.1. HG - 8 mmHG - 8 mm
2.2.Class II elastics - 3 mmClass II elastics - 3 mm
3.3.Torque - 1 to 2 mmTorque - 1 to 2 mm
4.4.Class III elastics + 2-3mmClass III elastics + 2-3mm
5.5.Facial mask + 2- 4mmFacial mask + 2- 4mm
• Point A and APO planePoint A and APO plane

VTO – Occlusal plane predictionVTO – Occlusal plane prediction
• Superimpose mark 2 on original menton along facialSuperimpose mark 2 on original menton along facial
planeplane
• Copy the occlusal planeCopy the occlusal plane
VTO - Dentition - Lower central incisorVTO - Dentition - Lower central incisor
• Superimpose on the corpus axis at PMSuperimpose on the corpus axis at PM
• Place a point 1mm above to occ. Plane &Place a point 1mm above to occ. Plane &
1mm ahead to APO line1mm ahead to APO line

VTO -VTO - DentitionDentition - Lower first molar- Lower first molar
• Arch length change is 4mmArch length change is 4mm
• Leeway space is 4mmLeeway space is 4mm
VTO -VTO - Dentition -Dentition - Upper first molarUpper first molar
Upper central incisorUpper central incisor
VTOVTO –– Soft tissue areaSoft tissue area

• Overall changes in size and relationship ofOverall changes in size and relationship of
human face from childhood to adulthoodhuman face from childhood to adulthood
are difficult to accurately predict due toare difficult to accurately predict due to
influence of the combined and complexinfluence of the combined and complex
effects of genetic and environment factor.effects of genetic and environment factor.

• Facial and dental changes in Adolescent and their clinicalFacial and dental changes in Adolescent and their clinical
implicationimplication
Samir –E Bishara ,AO 2000,Vol.60,No.6Samir –E Bishara ,AO 2000,Vol.60,No.6
• Difference between functional matrices in anterior open biteDifference between functional matrices in anterior open bite
and in deep biteand in deep bite
Melvin L. Moss, AJO 1970, Vol. 42,No.3Melvin L. Moss, AJO 1970, Vol. 42,No.3
• A principal of Arcial growth of the mandibleA principal of Arcial growth of the mandible
Robert M . Ricketts AJO 1972,Vol .42 ,No.4Robert M . Ricketts AJO 1972,Vol .42 ,No.4
• Provocations & perception in craniofacial orthopedicsProvocations & perception in craniofacial orthopedics
Robert M . RickettsRobert M . Ricketts
• Issues related to the prediction of craniofacial growthIssues related to the prediction of craniofacial growth
James Todd , AJO 1981,Vol .79 ,No. 2James Todd , AJO 1981,Vol .79 ,No. 2
• A soft tissue cephalometric analysis and it’s use inA soft tissue cephalometric analysis and it’s use in
orthodontic treatment planningorthodontic treatment planning
Holdway , AJO 1984 ,Vol. 84 ,No. 4Holdway , AJO 1984 ,Vol. 84 ,No. 4www.indiandentalacademy.comwww.indiandentalacademy.com

• A Visulized treatment objectiveA Visulized treatment objective
Alen Jacobson , P Lionel SadowskyAlen Jacobson , P Lionel Sadowsky
• Prediction of the mandibular growth rotationPrediction of the mandibular growth rotation
Bjork , AJO 1969 , Vol. 39Bjork , AJO 1969 , Vol. 39
• Bioprogessive Therapy – VTOBioprogessive Therapy – VTO
Ruel W Bench , James J. Higler , JCO 1977, NovemberRuel W Bench , James J. Higler , JCO 1977, November
• Contemporary orthodontics - William R. ProffitContemporary orthodontics - William R. Proffit
• Orthodontic current principles & techniquesOrthodontic current principles & techniques
T.M Graber , Robert VanarsdallT.M Graber , Robert Vanarsdall
• Orthodontic principles & practiceOrthodontic principles & practice
T.M GraberT.M Graber
• Ricketts interview ,JCO 1975 ,may, jun ,julyRicketts interview ,JCO 1975 ,may, jun ,july

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