Growth Prediction3 / orthodontic courses by Indian dental academy

GROWTH PREDICTIONGROWTH PREDICTION• IntroductionIntroduction• Definition Definition • UsesUses• MethodsMethods• LimitationLimitation INDIAN DENTAL ACADEMYINDIAN DENTAL ACADEMY

Leader in continuing dental education Leader in continuing dental education www.indiandentalacademy.comwww.indiandentalacademy.com

www.indiandentalacademy.comwww.indiandentalacademy.com

GROWTH PREDICTIONGROWTH PREDICTION

• IntroductionIntroduction• Scammon’s curveScammon’s curve• Cephalocaudal gradientCephalocaudal gradient• Data from various studiesData from various studies Bolton brush studyBolton brush study Iowa growth study Iowa growth study


GROWTH PREDICTIONGROWTH PREDICTION DefinitionDefinition • Assumption of ability to estimate Assumption of ability to estimate

practically future growth.practically future growth.• Asserting on the basis of theory, data Asserting on the basis of theory, data

or experience but in advance of or experience but in advance of proof.proof.


GROWTH PREDICTIONGROWTH PREDICTION

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

treatment plantreatment plan


Growth predictionGrowth predictionMethods 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


GROWTH PREDICTIONGROWTH PREDICTIONMethods of predicting facial growth Methods of predicting facial growth

changechangeAccording BjorkAccording Bjork• Longitudinal approachLongitudinal approach• Metric approachMetric approach• Structural approachStructural approach


Growth predictionGrowth prediction•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


Growth predictionGrowth predictiontype A – middle & lower face growth in type 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 faceType C – lower face < middle faceType C – lower face < middle face


Growth predictionGrowth prediction 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.• Limitation Limitation Accurate in Retrospective.Accurate in Retrospective.• Conclusion –Conclusion – Not accurate method.Not accurate method.


Growth predictionGrowth prediction• Metric approachMetric approach - consist of measuring different structure on a - consist of measuring different structure on a

single radiograph & then relating these single radiograph & then relating these measurement to future growth changes .measurement to future growth changes .

Correlation coefficient =rCorrelation coefficient =r- Association b/w 2 variableAssociation b/w 2 variable- Direction either positive or negative of the Direction 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 Squaring the value of ‘r’ = coefficient of

determination determination ( amount of variation of 2( amount of variation of 2ndnd variable ) variable )www.indiandentalacademy.comwww.indiandentalacademy.com

Growth predictionGrowth prediction • 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

Conclusion Conclusion this methods is least clinically siginificantthis methods is least clinically siginificant


Growth predictionGrowth prediction• Structural approachStructural approach- - To predict mandible To predict mandible

growth directiongrowth direction - - Superimposition on Superimposition on

metallic implantmetallic implant - 7 areas- 7 areas1.1. Inclination of condyleInclination of condyle2.2. Curvature of the Curvature of the

mandibular canal mandibular canal 3.3. Inclination of Inclination of

symphysissymphysiswww.indiandentalacademy.comwww.indiandentalacademy.com

Growth predictionGrowth prediction4.4. Shape lower border of Shape lower border of

the mandible the mandible 5.5. The interincisal angleThe interincisal angle6.6. The interpremolar or The interpremolar or

molar anglemolar angle7.7. The anterior lower The anterior lower

facial height facial height ConclusionConclusion This is also least clinically This is also least clinically

siginificantsiginificantwww.indiandentalacademy.comwww.indiandentalacademy.com

Growth predictionGrowth prediction• Skeiller ,Bjork, and Linde – HansenSkeiller ,Bjork, and Linde – Hansen (Tried to quantify it)(Tried to quantify it)• 4 variable 4 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 height2.2. The intermolar angleThe intermolar angle3.3. Shape of lower border of the mandible Shape 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 –Symphysis inclination (sym. Anterior surface –

SN)SN)


Growth predictionGrowth prediction• Measurement of these variables were Measurement of these variables were

includedincluded R squar = 0.8612 = 86% variation in R squar = 0.8612 = 86% variation in

direction of mandibular growthdirection of mandibular growth• But 86% was high valueBut 86% was high value


Growth predictionGrowth predictionMethods of predicting facial growth Methods of predicting facial growth

changechange 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


Growth predictionGrowth prediction• Computerized prediction methodsComputerized prediction methods• Tool of analysis not a methodTool of analysis not a method• AdvantageAdvantage1.1. Facilitates testingFacilitates testing2.2. Complex formulas to growth predictionComplex formulas to growth prediction


Growth predictionGrowth prediction• Ricketts 1970 – potential of Ricketts 1970 – potential of

computerizationcomputerization- 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 growth assumption 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.www.indiandentalacademy.comwww.indiandentalacademy.com


changechangeAccording BjorkAccording BjorkComputerized prediction methodsComputerized prediction methodsLogarithmic spiralLogarithmic spiralArcial growth of the mandibleArcial growth of the mandibleVisual treatment objectVisual treatment object


Growth predictionGrowth prediction

•Logarithmic spiralLogarithmic spiralGolden trianglesGolden trianglesWhyWhy how the position of 3 foramina on how the position of 3 foramina on

the unitary , logarithmic spiral in the unitary , logarithmic spiral in anterior open bite and deep bite pt. anterior open bite and deep bite pt. (Melvin. Moss ) (Melvin. Moss )


Logarithmic spiralLogarithmic spiral


Evolution of logarithmic Evolution of logarithmic spiralspiral• Sectioning of a lineSectioning of a line• Smaller section is proportional to large Smaller section is proportional to large

sectionsection• Larger portion is called ‘golden section’Larger portion is called ‘golden section’• Larger section is Phi / Larger section is Phi /


Evolution of logarithmic Evolution of logarithmic spiralspiral• Small section is 1Small section is 1• Larger = 1.618 Larger = 1.618

times the smallertimes the smaller• The smaller is The smaller is

0.618 the length of 0.618 the length of the largerthe larger


Evolution of logarithmic Evolution of logarithmic spiralspiral•Phi relationshipPhi relationship - Plants, animals, human body , face- Plants, animals, human body , face• Golden progression – series of these Golden progression – series of these

proportionsproportions- Symbols - - Symbols - 2 2 ,, 3 3 ,, 4 4


Evolution of logarithmic Evolution of logarithmic spiralspiral

• Golden triangleGolden triangle • Base of a triangle Base of a triangle

1.01.0• Sides of equilateral Sides of equilateral

triangle 1.618triangle 1.618• Forms a 72 – 72 -36 Forms a 72 – 72 -36

degreedegree



• Bisection of one base Bisection of one base angle cross the angle cross the opposite sideopposite side

• Divide that side into a Divide that side into a golden sectiongolden section

• Form new golden Form new golden triangletriangle


Evolution of logarithmic Evolution of logarithmic spiralspiral• Bisection of golden triangle can be made in a Bisection of golden triangle can be made in a

seriesseries



• Curve used to Curve used to connect the points on connect the points on a series of the a series of the trianglestriangles

• Form Logarithmic Form Logarithmic spiral.spiral.


Logarithmic spiralLogarithmic spiral• So human mandible So human mandible

grows as a grows as a logarithmic spiral on logarithmic spiral on the arc.the arc.


Logarithmic spiralLogarithmic spiral Melvin Moss Melvin Moss

• Aim - determine the position of 3 foramina on Aim - determine the position of 3 foramina on the unitary , logarithmic spiral in anterior open the unitary , logarithmic spiral in anterior open bite and deep bite pt.bite and deep bite pt.

• These conditions can be anticipated at young These conditions can be anticipated at young age even before orthodontic diagnosis age even before orthodontic diagnosis

• Foramen Foramen 1.1. Foramen ovaleForamen ovale2.2. Mandibular foramen inferior alveolar nerveMandibular foramen inferior alveolar nerve3.3. Mental foramenMental foramen


Logarithmic spiralLogarithmic spiral• IntroductionIntroductionStudied the position of the inferior Studied the position of the inferior

alveolar nervealveolar nerve

•ConclusionConclusionThese foramina , at all ages fit These foramina , at all ages fit

precisely upon a single precisely upon a single mathematically defined logarithmic mathematically defined logarithmic spiralspiral



Foramen “moved” down Foramen “moved” down along this same along this same logarithmic spiral in logarithmic spiral in geometric fashiongeometric fashion

The gradient of motion The gradient of motion directly increasing with directly increasing with the distance of the the distance of the foramina from cranial foramina from cranial base. base.


Logarithmic spiralLogarithmic spiral•Method and materialsMethod and materials 2 group of pt.2 group of pt. Columbia university University of Columbia university University of

utahutah 16 pt - 3 m & 4 f 4 groups 16 pt - 3 m & 4 f 4 groups

(Ant Open bite) 10 pt Normal swallowers (Ant Open 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 bite 5 pt Ant open bite www.indiandentalacademy.comwww.indiandentalacademy.com


• Tracing of cranial base & mandibular Tracing of cranial base & mandibular outline from filmsoutline from films

• Superimposed the logarithmic spiral Superimposed the logarithmic spiral

• Position of 3 foramen marked on it.Position of 3 foramen marked on it.


Logarithmic spiralLogarithmic spiral• ResultResult Singular position of Singular position of

foramen ovale in foramen ovale in anterior open bite.anterior open bite.

Foramen ovale Foramen ovale located farther located farther down the spiral. down the spiral.

Help in diagnosis Help in diagnosis No sexual No sexual

dimorphism dimorphism www.indiandentalacademy.comwww.indiandentalacademy.com

Logarithmic spiralLogarithmic spiral Mandibular & mental Mandibular & mental

foramen also further foramen also further down the logarithmic down the logarithmic spiral in AOBspiral in AOB

Not as diagnostically Not as diagnostically uniqueunique

Distance between Distance between these not decreased.these not decreased.



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


Logarithmic spiralLogarithmic spiral Discussion Discussion Mandibular shapeMandibular shape - inferior alveolar nerve - inferior 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 - All foramina placed near the origin of spiral

and nearer to each otherand nearer to each other - Flatter curvature - Flatter curvature - Mandible gonial angle relatively obtuse or - Mandible gonial angle relatively obtuse or

flat.flat. www.indiandentalacademy.comwww.indiandentalacademy.com

Logarithmic spiralLogarithmic spiral With growth , all foramina moved down With growth , all foramina moved down

along the spiral and distance along the spiral and distance

• Ramus becomes more erect relatively to Ramus becomes more erect relatively to corpuscorpus

• Gonial angle becomes acuteGonial angle becomes acutewww.indiandentalacademy.comwww.indiandentalacademy.com

Logarithmic spiralLogarithmic spiral• Anterior open biteAnterior open bite Foramen ovale down Foramen ovale down

along the spiralalong the spiral

Distance mand. &mental Distance mand. &mental foramen not decreaseforamen not decrease

Course of inferior Course of inferior alveolar nerve flatteralveolar nerve flatter

Ramus & corpus more Ramus & corpus more obutse obutse www.indiandentalacademy.comwww.indiandentalacademy.com

Logarithmic spiralLogarithmic spiral• Deep biteDeep bite‘‘Higher’ up on the Higher’ up on the

spiralspiral

3 neural foramina 3 neural foramina distance not decreaseddistance not decreased

Inferior alveolar nerve Inferior alveolar nerve curvilinear coursecurvilinear course

Ramus & corpus more Ramus & corpus more acute acute


Logarithmic spiralLogarithmic spiral• Anterior cranial base – Richardson Anterior cranial base – Richardson Sella - NASella - NA

Deep biteDeep bite

AnteriorAnterioropen biteopen bite


Logarithmic spiralLogarithmic spiral 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 significantCorpus Normal length linear differenceCorpus Normal length linear difference

• Anterior cranial baseAnterior cranial base(S-Na) No difference (S-Na) No difference


Logarithmic spiralLogarithmic spiral 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



changechangeAccording BjorkAccording BjorkComputerized prediction methodsComputerized prediction methodsLogarithmic spiralLogarithmic spiralArcial growth of the mandibleArcial growth of the mandibleVisual treatment objectiveVisual treatment objective


Principal of Arcial growth of the Principal of Arcial growth of the mandiblemandible Robert M. RickettsRobert M. Ricketts

• Purpose Purpose – explain a method for finding the arcial – explain a method for finding the arcial growth of the mandible and to enumerate some growth of the mandible and to enumerate some uses of the principaluses of the 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

•Principal Principal – mandible grows by – mandible grows by superior-anterior apposition at the superior-anterior apposition at the ramus on a curve or arc which is a ramus on a curve or arc which is a segment formed from a circle.segment formed from a circle.

• Radius – Pm to point Eva.Radius – Pm to point Eva.


Arcial growth of the mandibleArcial growth of the mandible• Growth of the mandibleGrowth of the mandible1.1. Roentgenographic cephalometricRoentgenographic cephalometric2.2. Bjork Bjork 3.3. EnlowEnlow Bjork Bjork - variation in the mandibular bending.variation in the mandibular bending.- Resorption of lower angular borderResorption of lower angular border- 33rdrd molar crypt – stable longitudinal molar crypt – stable longitudinal

reference reference Enlow Enlow 3D growth pattern Remodeling area3D growth pattern Remodeling area Reversal areas of stability Reversal areas of stability


Arcial growth of the mandibleArcial growth of the mandible Prediction of mandibular growthPrediction of mandibular growth• Primary methods Primary 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 External mandible (mandibular plane,ramus

plane, condyle – symphysis )plane, condyle – symphysis )



• Xi pointXi point – center of – center of ramusramus

Occlusal planeOcclusal planeEntrance of Entrance of

neurotrophic bundlesneurotrophic bundles


Arcial growth of the Arcial growth of the mandiblemandible• Bisect the height of ramus from the Bisect the height of ramus from the

sigmoid notchsigmoid notch


Arcial growth of the Arcial growth of the mandiblemandible



• Dc pointDc point• Condyle axisCondyle axis• Corpus axis Corpus axis • Change in angle - Change in angle -

change in mandibular change in mandibular formform

• Second methodSecond method – –Magnitude & angular Magnitude & angular relation.relation.

• More successful as a More successful as a method of forecasting method of forecasting



• Suprapogonion / Suprapogonion / PmPm

Reference pointReference pointRicketts – stress Ricketts – stress

centercenterEnlow – site of Enlow – site of

reversal linereversal lineBjork - cosistentBjork - cosistent



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



computer studycomputer study• 5 yrs growth study of mandible & 5 yrs growth study of mandible &

lower dental archlower dental arch• In lateral & frontal head films -362 In lateral & frontal head films -362

measurement measurement



MaterialMaterial• 40 pt – lateral & frontal cephalometric 40 pt – lateral & frontal cephalometric

filmfilm• 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 ½ Mandible bend ½

degree per year.degree per year.• Bending in an Bending in an

orderly manner.orderly manner.• Growth arc was Growth arc was

operative.operative.



• First arc – Pm ,Xi ,DcFirst arc – Pm ,Xi ,Dc• Straightening of the Straightening of the

mandiblemandible

• To determine the true arc of growth of To determine the true arc of growth of the mandiblethe mandible



•Second arcSecond arc - tip of - tip of coronoid , R1 , Pmcoronoid , R1 , Pm

• Segment of circle small Segment of circle small in radius.in radius.

• Excessive bending of Excessive bending of mandiblemandible


Arcial growth of the mandibleArcial growth of the mandible• True arcTrue arc – Condylar & – Condylar &

Coronoid process , Coronoid process , Ramus center & it’s ant. Ramus center & it’s ant.

BorderBorder• Radius increase or Radius increase or

changing with the size of changing with the size of the mandiblethe mandible

• Changing arc or ultimate Changing arc or ultimate spiral would result.spiral would result.

• Growth could not be Growth could not be represented as simple represented as simple segment of circle segment of circle



Stress linesStress lines• 850 yrs. Old 850 yrs. Old

mandible – William mandible – William B. DownsB. Downs

• Disintegration of Disintegration of interprismatic subs.interprismatic subs.

• Stress lines in the Stress lines in the outer & inner platesouter & inner plates



• Examination of Examination of stress lines / stress lines / lateral surfacelateral surface

Convergence at Convergence at protuberance mentiprotuberance menti

Upward ,backward & Upward ,backward & outward from EOoutward from EO

Gnarled area at the Gnarled area at the coronoid base.coronoid base.


Arcial growth of the mandibleArcial growth of the mandible• Stress line /medial Stress line /medial

sideside Mylohyoid ridgeMylohyoid ridge YM /Y-shaped bony YM /Y-shaped bony

prominenceprominence - Center of quadrant of - Center of quadrant of

ramusramus - Inner & outer cortical - Inner & outer cortical

tables showed confluencetables showed confluence TP/ Triangular plane – TP/ Triangular plane –

Nutritive foraminaNutritive foramina



• 2 new point2 new point - Eva &TR - Eva &TR• EvaEva- forking of stress - forking of stress

lines in ramuslines in ramus

• TR /true radiusTR /true radius – – center of circle from center of circle from Pog through EvaPog through Eva

• Mu pointMu pointwww.indiandentalacademy.comwww.indiandentalacademy.com


• Mandible size Mandible size increased, increment increased, increment added to the arc at the added to the arc at the sigmoid notch.sigmoid notch.

• Predicted mandible was Predicted mandible was almost absolutely almost absolutely correct in size and form correct in size and form when compared with when compared with the final compositethe final composite



• Mandible growth Mandible growth occurs on a arcoccurs on a arc

• This method proved This method proved extremely accurate extremely accurate in 50 treated cases in 50 treated cases which were which were predicted and predicted and compared for compared for periods of as long periods of as long as 14 yrs later.as 14 yrs later. www.indiandentalacademy.comwww.indiandentalacademy.com


• Amount of growth to Amount 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 lower Symphysis lower borderborder – 1mm each 8 – 1mm each 8

yrs / Myrs / M



• Coronoid & condylar Coronoid & condylar processprocess – different – different

• CoronoidCoronoid – 0.8mm/yr – 0.8mm/yr

• Condylar Condylar - variable - variable1.1. Short & weak – 0.0mmShort & weak – 0.0mm2.2. Long condyles – Long condyles –

0.4mm/yr0.4mm/yr3.3. Average – 0.2mm /yr Average – 0.2mm /yr



• Gonion angleGonion angle growth growth 50% of the total 50% of the total increase in mandibular increase in mandibular growthgrowth

• Females - no further Females - no further addition addition

• Males – above +0.2mmMales – above +0.2mm



•External oblique External oblique ridgeridge

0.4mm/yr.0.4mm/yr.

• RR point – stable boneRR point – stable bone Ramal widthRamal width


Arcial growth of the mandibleArcial growth of the mandible• Impaction of third molar and Arcial Impaction of third molar and Arcial

growth prognosis –growth prognosis –25 adult skull 25 adult skull normal occlusion normal occlusion

1.1. Lower third molar 50 % ahead the EORLower third molar 50 % ahead the EOR 50% favorable prognosis50% favorable prognosis2.2. Mesial to the EOR – 100 % favorable prognosis Mesial to the EOR – 100 % favorable prognosis 3.3. Distal to the EOR – poorer Distal to the EOR – poorer 45 % of the nonextracted cases required third 45 % of the nonextracted cases required third

molar extraction.molar extraction.


Arcial growth of the Arcial growth of the mandiblemandible• Bisect the height of ramus from the Bisect the height of ramus from the

sigmoid notch down to the lower sigmoid notch down to the lower border in a perpendicular plane from border in a perpendicular plane from FH ,then bisected the width of the FH ,then bisected the width of the mandible called XI pointmandible called XI point


Arcial growth of the Arcial growth of the mandiblemandible



• Xi pointXi point – center of – center of ramusramus

Occlusal planeOcclusal planeEntrance of Entrance of

neurotrophic bundlesneurotrophic bundles



• 2 new point2 new point - Eva &TR - Eva &TR• EvaEva- forking of stress lines - forking of stress lines

in ramusin ramus• A center of upward & A center of upward &

forward quadrant of ramusforward quadrant 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 pointwww.indiandentalacademy.comwww.indiandentalacademy.com


• Class IIIClass IIIThe amount of The amount of

mandibular growth in mandibular growth in the forecast is one the forecast is one sixth more in the sixth more in the classIIIclassIII



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



changechangeAccording BjorkAccording BjorkLogarithmic spiralLogarithmic spiralArcial growth of the mandibleArcial growth of the mandibleComputerized prediction methodsComputerized prediction methodsVisualized treatment objectiveVisualized treatment objective


Visualized treatment Visualized treatment objectiveobjective• DefinitionDefinition• UsesUses• Jacobson and SadowskyJacobson and Sadowsky• RickettsRicketts• HoldwaysHoldways


Visualized treatment Visualized treatment objectiveobjective

•Definition Definition It is a visual plan to forecast the normal It is a visual plan to forecast the normal

growth of the pt and the anticipated growth of the pt and the anticipated influences of treatment , to establish the influences of treatment , to establish the individual objectives we want to achieve individual objectives we want to achieve for that ptfor that pt



• Uses Uses 1.1. Predict growth over an estimated T/t Predict growth over an estimated T/t

timetime2.2. Analyzes the soft tissue facial profileAnalyzes the soft tissue facial profile3.3. Determines favourable incisor Determines favourable incisor

repositioning based on an ‘ideal’ repositioning based on an ‘ideal’ projected soft tissue profileprojected soft tissue profile

4.4. Determines total arch length discrepancyDetermines total arch length discrepancywww.indiandentalacademy.comwww.indiandentalacademy.com

Visualized treatment Visualized treatment objectiveobjective5.5. Aids in determining b/w extraction Aids in determining b/w extraction

& nonextraction treatment& nonextraction treatment6.6. Surgical orthodontic correctionSurgical orthodontic correction


Visualized treatment Visualized treatment objectiveobjective• Jacobson and SadowskyJacobson and Sadowsky• RickettsRicketts• HoldwaysHoldways


Visualized treatment objectiveVisualized treatment objective ALEX JACOBSON & ALEX JACOBSON & P.LIONEL SADOWSKY P.LIONEL SADOWSKY

• All cephalometric headfilms to be taken in the All cephalometric headfilms to be taken in the lips closed position even if they are strained to lips closed position even if they are strained to closeclose

• Construct a VTO by considering average Construct a VTO by considering average growth for an estimated 2 yr period of active growth for an estimated 2 yr period of active t/t & the objective we want to achieve with our t/t & the objective we want to achieve with our mechanicsmechanics



Cephalometric tracing for VTOCephalometric tracing for VTO• Anterior & posterior cranial base Anterior & 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 meatus External auditory meatus • Soft tissue profiles Soft tissue profiles • Upper & lower molar Upper & lower molar www.indiandentalacademy.comwww.indiandentalacademy.com

Visualized treatment Visualized treatment objectiveobjective 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 plane Occlusal 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 & Step 1 obj. – To draw frontonasal area , BAN &

NA line.NA line.

• StStep 2ep 2 obj. – Growth in frontonasal area over 2 obj. – Growth in frontonasal area over 2 yr.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 )


Visual treatment objectiveVisual treatment objective• Step 3 objectStep 3 object – Mandible growth in vertical – Mandible growth in vertical

direc.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 The distance b/w VTO & ceph Ban line should be

3 times the amount of growth expressed 3 times the amount of growth expressed previously in FN areapreviously in FN area


Visual treatment objectiveVisual treatment objective 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 Total vertical facial height as well as

forward location of chin establishedforward location of chin established


Visual treatment objectiveVisual treatment objectiveStep 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 There is 40% of total vertical growth above BaN

line & 60% below mandibleline & 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% Vertical growth is 50% above maxilla & 50%

below mandiblebelow mandiblewww.indiandentalacademy.comwww.indiandentalacademy.com

Visual treatment objectiveVisual treatment objective Step 7 objStep 7 obj. – To determine soft tissue lip . – To determine soft tissue lip

contour using the new H-linecontour using the new H-line

• The distance b/w upper lip contour & H-line is The distance b/w upper lip contour & H-line is 3 - 7mm (Dr. Holdway’s studies )3 - 7mm (Dr. Holdway’s studies )


Visual treatment objectiveVisual treatment objective Step 8 objStep 8 obj. – To relocate the maxillary central incisor. – To relocate the maxillary central incisor• Upper lip thickness = Basic upper lip thickness Upper lip thickness = Basic upper lip thickness ( within 1 mm )( within 1 mm )• Lip strain is difference b/w above measurement Lip 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 case In 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


Visual treatment objectiveVisual treatment objective 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/w Arch 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


Visual treatment objectiveVisual treatment objectiveStep 10 objStep 10 obj.. – –To reposition mandibular first molarTo reposition mandibular first molar

• Total arch length discrepancy = arch length Total arch length discrepancy = arch length loss +arch length discrepancy / model loss +arch length discrepancy / model discrepancydiscrepancy

8 mm = 4 mm + 4mm8 mm = 4 mm + 4mm

• Extraction of 2Extraction of 2ndnd PM on both side - 15 mm PM on both side - 15 mm space space

Step 11 objStep 11 obj. – To reposition the maxillary first . – To reposition the maxillary first www.indiandentalacademy.comwww.indiandentalacademy.com

Visualized treatment Visualized treatment objectiveobjective• Jacobson and SadowskyJacobson and Sadowsky• HoldwaysHoldways• RickettsRicketts


A Soft - tissue cephalometric A 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 Sella nasion line is used express forward

growth at nasiongrowth at nasion• Growth on facial axis is 3mm/yr except Growth on facial axis is 3mm/yr except

during growth spurtsduring growth spurts


A Soft - tissue cephalometric A Soft - tissue cephalometric analysisanalysis

• Head films should be taken with the Head films should be taken with the pt’s lip touching positionpt’s lip touching position



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 axis Facial axis • Down’s Mandibular planeDown’s Mandibular plane


A Soft - tissue cephalometric A Soft - tissue cephalometric analysisanalysis Steps of VTO tracing Steps of VTO tracing Step 1 – Draw Frontonasal area Step 1 – Draw Frontonasal area Sella – nasion lineSella – nasion line Nasion- point A lineNasion- point A line



Step 2 - Express horizontal growth in Step 2 - Express horizontal growth in the FN area for the estimated T/tthe FN area 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 overall Prediction of growth at nasion is an overall

prediction for all midfacial structure prediction for all midfacial structure



Step 3 Step 3 – Mandible growth in vertical dire.– Mandible growth in vertical dire.• Growth on facial axis is 3 mm/yr except in Growth on facial axis is 3 mm/yr except in

growth spurt periodgrowth spurt period

Step 4 Step 4 – Mandible growth in horizontal – Mandible growth in horizontal dire.dire.

• At this point total vertical height has been At this point total vertical height has been forecastforecast



Step 5 Step 5 – To locate maxilla, the new – To locate maxilla, the new point A & lower half of nosepoint A & lower half of nose

• Vertical growth above the SN line & below Vertical growth above the SN line & below the mandible is in ratio of 40 :60the mandible is in ratio of 40 :60

• The vertical growth of the nose over 2 yr The vertical growth of the nose over 2 yr period keeps pace with the growth from the period keeps pace with the growth from the maxilla vertically to the anterior cranial base maxilla vertically to the anterior cranial base



Step 6 - Step 6 - locate and draw the occlusal locate and draw the occlusal planeplane

• Vertical growth is 50% above maxilla & Vertical growth is 50% above maxilla & 50% below mandible50% below mandible

• The occlusal plane is located 3 mm below The occlusal plane is located 3 mm below the lip embrasurethe lip embrasure



Step 7Step 7 – – To determine soft tissue lip To determine soft tissue lip contour using the new H-linecontour using the new H-line

• The distance b/w upper lip contour & H-line is The distance b/w upper lip contour & H-line is 3 - 7mm 3 - 7mm • Short & thin lip – 3 mmShort & thin lip – 3 mm• Long & thick lip – 5 mmLong & thick lip – 5 mm



Step 8 Step 8 – – To relocate the maxillary central To relocate the maxillary central incisorincisor

• Upper lip thickness = Basic upper lip thickness Upper lip thickness = Basic upper lip thickness ( within 1 mm )( within 1 mm )• Lip strain is difference b/w above measurement Lip 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 9 Step 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 new Arch length change - distance b/w old and new incisor position incisor 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



Step 10 Step 10 – – To reposition mandibular first molarTo reposition mandibular first molar

• Total arch length discrepancy = arch length Total arch length discrepancy = arch length change +arch length discrepancy / model change +arch length discrepancy / model discrepancydiscrepancy

10 mm = 8mm + 2mm10 mm = 8mm + 2mm• Extraction of 2Extraction of 2ndnd PM on both side - 15 mm space PM on both side - 15 mm space

Step 11Step 11 – To reposition the maxillary first – To reposition the maxillary first


Visualized treatment Visualized treatment objectiveobjective• Jacobson and SadowskyJacobson and Sadowsky• HoldwaysHoldways• RickettsRicketts


Visualized treatment Visualized treatment objective objective RICKETTSRICKETTS Original tracingOriginal tracing

• NasionNasion• ANSANS• Point APoint A• PMPM• POGPOG• CCCC• Basion Basion • DCDC• XIXI


Visualized treatment Visualized treatment objective objective Construction of VTOConstruction of VTO• Cranial base prediction Cranial 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

Visualized treatment Visualized treatment objective objective


Visualized treatment objective Visualized treatment objective

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


VTOVTO – – Mandibular growth prediction – RotationMandibular growth prediction – Rotation

• Mandible rotates open or closed from the effects of Mandible rotates open or closed from the effects of mechanics used & the facial pattern present mechanics used & the facial pattern present

• MechanicsMechanics 5 mm convexity reduction Facial axis open 1 5 mm convexity reduction Facial axis open 1

degree degree

4 mm overbite correction 4 mm overbite correction

• Facial patternFacial pattern




VTO – VTO – Mandibular growth prediction – Mandibular growth prediction – RotationRotation

• Superimpose at BasionSuperimpose at Basion• Rotate VTO tracing up to open the bite at nasion Rotate VTO tracing up to open the bite at nasion

or down to open the biteor down 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 growth PM moves forward 2mm /yr in normal growth

VTO – Mandibular growth prediction -VTO – Mandibular growth prediction -Symphysis growthSymphysis growth

• 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 Divide the original & new menton into 3 part

by using 2 markby using 2 mark• Superimpose mark 1 on original menton , Superimpose mark 1 on original menton ,

copy the maxillacopy the maxilla



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 Position of Point A change with growth & different mechanicsmechanics

Mechanics Maximum rangeMechanics Maximum range1.1. HG - 8 mmHG - 8 mm2.2.Class II elastics - 3 mmClass II elastics - 3 mm3.3.Torque - 1 to 2 mmTorque - 1 to 2 mm4.4.Class III elastics + 2-3mmClass III elastics + 2-3mm5.5.Facial mask + 2- 4mmFacial mask + 2- 4mm• Point A and APO planePoint A and APO planewww.indiandentalacademy.comwww.indiandentalacademy.com


VTO – Occlusal plane predictionVTO – Occlusal plane prediction• Superimpose mark 2 on original menton along Superimpose mark 2 on original menton along

facial planefacial plane• 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 - Dentition Dentition - 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 molar Upper first molar Upper central incisorUpper central incisor VTOVTO – – Soft tissue areaSoft tissue area


Growth predictionGrowth prediction• Overall changes in size and Overall changes in size and

relationship of human face from relationship of human face from childhood to adulthood are difficult to childhood to adulthood are difficult to accurately predict due to influence of accurately predict due to influence of the combined and complex effects of the combined and complex effects of genetic and environment factor.genetic and environment factor.


Growth predictionGrowth prediction• Facial and dental changes in Adolescent and their clinical Facial and dental changes in Adolescent and their clinical

implication implication Samir –E Bishara ,AO 2000,Vol.60,No.6Samir –E Bishara ,AO 2000,Vol.60,No.6• Difference between functional matrices in anterior open Difference between functional matrices in anterior open

bite and in deep bitebite and 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 in A 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. 4


Growth predictionGrowth prediction• A Visulized treatment objectiveA Visulized treatment objective Alen Jacobson , P Lionel Sadowsky Alen 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 – VTO Bioprogessive Therapy – VTO Ruel W Bench , James J. Higler , JCO 1977, Ruel W Bench , James J. Higler , JCO 1977,

NovemberNovember• 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 ,julywww.indiandentalacademy.comwww.indiandentalacademy.com


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