growth prediction2 / orthodontic courses by indian dental academy

Holdaway’s soft-tissue Holdaway’s soft-tissue VTOVTO

• Purpose is to establish a balanced Purpose is to establish a balanced profile and pleasing facial esthetics profile and pleasing facial esthetics and to evaluate the orthodontic and to evaluate the orthodontic correction necessary to achieve this correction necessary to achieve this goalgoal

• Holdaway VTO emphasizes soft Holdaway VTO emphasizes soft tissue profile balancetissue profile balanceINDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

• Growth of the cranio-facial skeleton is Growth of the cranio-facial skeleton is predicted for the estimated treatment predicted for the estimated treatment time, and the soft tissue profile between time, and the soft tissue profile between the nose and the chin arranged to create the nose and the chin arranged to create an “ideal” facial profile for the individual an “ideal” facial profile for the individual patientpatient

• Maxillary and mandibular incisors are Maxillary and mandibular incisors are repositioned to eliminate lip strainrepositioned to eliminate lip strain

• Allowance is made for probable post Allowance is made for probable post treatment treatment ““incisor reboundincisor rebound””

• Maxillary teeth are positioned first, and Maxillary teeth are positioned first, and then lower incisors are repositioned to be then lower incisors are repositioned to be in harmony with the upper incisorsin harmony with the upper incisors


• Following the repositioning of the Following the repositioning of the mandibular incisors, the resultant mandibular incisors, the resultant arch length discrepancy may be arch length discrepancy may be calculated to determine whether or calculated to determine whether or not teeth should be extracted not teeth should be extracted


• The VTO is thus a dynamic The VTO is thus a dynamic cephalometric analysis which takes cephalometric analysis which takes into account both growth and into account both growth and biomechanics, thus achieving its aim of biomechanics, thus achieving its aim of being a Visualized Treatment Objectivebeing a Visualized Treatment Objective

• It outlines a goal from the inception of It outlines a goal from the inception of treatment and may be usefully treatment and may be usefully employed in monitoring growth and employed in monitoring growth and treatment progresstreatment progress


• In sum, therefore the VTO accomplishes :In sum, therefore the VTO accomplishes :Predicts growth over an estimated Predicts growth over an estimated treatment time, based on the individual treatment time, based on the individual morphogenetic patternmorphogenetic patternAnalyzes the soft tissue facial profileAnalyzes the soft tissue facial profileGraphically plans the best soft tissue Graphically plans the best soft tissue facial profile for the particular patientfacial profile for the particular patientDetermines favorable incisor Determines favorable incisor repositioning, based on an “ideal” repositioning, based on an “ideal” projected soft tissue facial profileprojected soft tissue facial profile


Assists in determining total arch length Assists in determining total arch length discrepancy when taking into account discrepancy when taking into account “cephalometric correction”“cephalometric correction”Aids in determining between extraction Aids in determining between extraction and nonextraction treatmentand nonextraction treatmentAids in deciding which teeth to extractAids in deciding which teeth to extractAssists in planning treatment mechanicsAssists in planning treatment mechanicsSurgery vs. non-surgerySurgery vs. non-surgeryIt provides a visual goal or objective for It provides a visual goal or objective for which to strive during treatmentwhich to strive during treatment


OJECTIVE : To draw frontonasal OJECTIVE : To draw frontonasal area, line BaN and line NAarea, line BaN and line NA


OBJECTIVE : To express growth in the OBJECTIVE : To express growth in the frontonasal area over a two-year periodfrontonasal area over a two-year periodSuper impose on line BaN and move the Super impose on line BaN and move the VTO until there is 1.5 mm growth in the VTO until there is 1.5 mm growth in the

fronto nasal areafronto nasal areaHolding the VTO tracing in the position Holding the VTO tracing in the position

copy the Ricketts facial axiscopy the Ricketts facial axiswww.indiandentalacademy.com

OBJECTIVE : To express growth in a OBJECTIVE : To express growth in a vertical direction in the mandible, and vertical direction in the mandible, and

to draw the anterior portion of the to draw the anterior portion of the mandible, soft tissue chin and the mandible, soft tissue chin and the

mandibular plane of Downsmandibular plane of DownsSuperimpose the VTO facial axis along the Superimpose the VTO facial axis along the original facial axis. Move the VTO tracing original facial axis. Move the VTO tracing

upwards so that the VTO BaN line is above the upwards so that the VTO BaN line is above the original BaN line, the distance between these original BaN line, the distance between these

lines should be three times the amount of lines should be three times the amount of growth expressed in the frontonasal areagrowth expressed in the frontonasal area


OBJECTIVE : To express growth in a horizontal OBJECTIVE : To express growth in a horizontal direction in the mandible and draw the direction in the mandible and draw the

posterior border of the mandibleposterior border of the mandibleMove the VTO forward until the original and Move the VTO forward until the original and VTO foramen rotundae are vertically alignedVTO foramen rotundae are vertically aligned


OBJECTIVE : To locate and draw the OBJECTIVE : To locate and draw the maxilla, and lower half of the nosemaxilla, and lower half of the nose

Super impose the VTO NA line on the Super impose the VTO NA line on the original NA line and move the VTO up original NA line and move the VTO up until the vertical growth is expressed until the vertical growth is expressed

above the BaN line and below the above the BaN line and below the mandibular plane is in the ratio of mandibular plane is in the ratio of

40:6040:60www.indiandentalacademy.com

OBJECTIVE : To locate and draw the occlusal OBJECTIVE : To locate and draw the occlusal planeplane

With the VTO superimposed on line NA, move With the VTO superimposed on line NA, move the VTO tracing so that the vertical growth the VTO tracing so that the vertical growth

between the maxilla and the mandible is between the maxilla and the mandible is expressed as being 50% above the maxilla and expressed as being 50% above the maxilla and

50% below the mandible50% below the mandiblewww.indiandentalacademy.com

OBJECTIVE : TO determine the soft OBJECTIVE : TO determine the soft tissue lip contour using the Holdaway tissue lip contour using the Holdaway

lineline


OBJECTIVE : to reposition lower incisor and OBJECTIVE : to reposition lower incisor and calculate resultant arch length changecalculate resultant arch length changejudge the position of the lower incisorjudge the position of the lower incisorTo calculate lower arch length change, To calculate lower arch length change,

superimpose tracing on mandibular plane and superimpose tracing on mandibular plane and register on symphysis. Measure the distance register on symphysis. Measure the distance

between old and new incisor position and between old and new incisor position and double this measurement to determine total double this measurement to determine total

arch length discrepancyarch length discrepancywww.indiandentalacademy.com

OBJECTIVE : To reposition lower first molar, OBJECTIVE : To reposition lower first molar, use the plaster casts to determine arch length use the plaster casts to determine arch length discrepancy due to crowding and/or rotation.discrepancy due to crowding and/or rotation.


OBJECTIVE : To reposition maxillary first OBJECTIVE : To reposition maxillary first molarmolar

Using the occlusal plane and lower first molar Using the occlusal plane and lower first molar as a guide draw the maxillary first molar in as a guide draw the maxillary first molar in good Class I occlusion with the lower first good Class I occlusion with the lower first

molarmolar


OBJECTIVE : To complete art workOBJECTIVE : To complete art workANS to upper incisorANS to upper incisor

Anterior portion of hard palateAnterior portion of hard palateLower alveolus lingually and labiallyLower alveolus lingually and labially


A statistical evaluation of A statistical evaluation of the Ricketts and Johnston the Ricketts and Johnston

growth-forecasting growth-forecasting methodsmethods


• Four methods of growth forecasting were Four methods of growth forecasting were comparedcompared– Johnston forecast gridJohnston forecast grid– Ave. increments from sella-nasionAve. increments from sella-nasion– Ricketts short-range predictionRicketts short-range prediction– Computer forecastComputer forecast

• Objective was to predict the final position Objective was to predict the final position of the points A, Pogonion, end of the nose, of the points A, Pogonion, end of the nose, lower molar and point Xi with respect to lower molar and point Xi with respect to cranial reference linescranial reference lines


• The Johnston The Johnston forecast gridforecast grid


• Errors were squared, summed, and Errors were squared, summed, and divided by the number in the sample divided by the number in the sample to get the mean-square error. to get the mean-square error. Square root was taken for the rot-Square root was taken for the rot-mean-squared errormean-squared error

• 70% of the predictions will be within 70% of the predictions will be within ±1 rms error ±1 rms error

• 95 % will be within ±2 rms error95 % will be within ±2 rms error


• Ave. increments from sella-nasionAve. increments from sella-nasionTo study points not included in Johnston To study points not included in Johnston forecast grid, as well as grid’s forecast grid, as well as grid’s applicability to a 10-year growth periodapplicability to a 10-year growth periodAverage increments for each of the Average increments for each of the points under consideration were points under consideration were calculated from SN with S as the origin, calculated from SN with S as the origin, and these increments were then used in and these increments were then used in a prediction as follows: Using sella-a prediction as follows: Using sella-nasion as a horizontal axis with sella as nasion as a horizontal axis with sella as its center, ave. increments per year its center, ave. increments per year were addedwere added


• Girls - 15 yearsGirls - 15 years• Boys - 19 yearsBoys - 19 years


• The Ricketts The Ricketts short-range short-range predictionprediction


• Computer forecastComputer forecastIndividual growth curves are used for Individual growth curves are used for the mandible, maxilla, and cranial base the mandible, maxilla, and cranial base rather than using the same increments rather than using the same increments for every age groupfor every age groupAbnormal growth with RMDS data bankAbnormal growth with RMDS data bank


Patients who grow abnormally large mandibles with lessgrowth in the cranial base – abnormal Class III patterns


Unusually strong patterns which Unusually strong patterns which rotate forwardrotate forward


Abnormally weak facial patterns – they rotate Abnormally weak facial patterns – they rotate distally distally


ResultsResultsJohnston gridJohnston grid

Least accurateLeast accurateIt was accurate as any for predicting It was accurate as any for predicting the nosethe nose64 percent accurate for Point A64 percent accurate for Point A70 percent accurate on Pogonion70 percent accurate on Pogonion


S-N average incrementsS-N average incrementsImprovement over the Johnston grid at Improvement over the Johnston grid at both Pogonion and point Aboth Pogonion and point A


Ricketts short-range prediction methodRicketts short-range prediction methodLess rms error than Johnston grid or SN average Less rms error than Johnston grid or SN average incrementsincrements

Some of the smaller over-all error was due to the Some of the smaller over-all error was due to the fact that point CC, the origin of this growth fact that point CC, the origin of this growth prediction, is closer to Pogonion than to Sellaprediction, is closer to Pogonion than to Sella

10 to 20 percent improvement of this method 10 to 20 percent improvement of this method over average increments over average increments


RMDS computer programRMDS computer programBased on theories of RickettsBased on theories of RickettsIndividualized further by using growth rates Individualized further by using growth rates variable for the patient’s age and by variable for the patient’s age and by recognising unusual facial patternsrecognising unusual facial patterns Most accurate of the four methodsMost accurate of the four methods 21% more accurate than Ricketts21% more accurate than Ricketts 56% more accurate than Johnston 56% more accurate than Johnston

gridgrid


If the actual growth was far different If the actual growth was far different from the predicted growth, the records from the predicted growth, the records were often returned to the laboratory so were often returned to the laboratory so that a file of “abnormal growth “ could be that a file of “abnormal growth “ could be compiledcompiledA consistent type emerged – one which A consistent type emerged – one which grew more in the mandible and less in the grew more in the mandible and less in the cranial base than predictedcranial base than predicted

Prediction of abnormal Prediction of abnormal growth in Class III growth in Class III

malocclusionsmalocclusions


• The three most consistent The three most consistent measurements which deviated from measurements which deviated from the normal in these patients were the normal in these patients were ramus position, porion location and ramus position, porion location and cranial deflectioncranial deflection

• Predictor measurementsPredictor measurements• Hokkaido University Orthodontic Hokkaido University Orthodontic

DepartmentDepartment


• For cranial deflection, porion For cranial deflection, porion location and ramus position the location and ramus position the greater the value, the more likely greater the value, the more likely the patient is hypothesized to have a the patient is hypothesized to have a Class III growth patternClass III growth pattern

• With molar relation, the lesser the With molar relation, the lesser the value, the more likely the patient is value, the more likely the patient is to have a Class III malocclusionto have a Class III malocclusion


Clinical norm Clinical norm (CN) (CN)

Standard Standard DeviationDeviation

Cranial Cranial deflection deflection

2828 3.03.0

Ramus Ramus positionposition

75.575.5 2.82.8

Porion Porion locationlocation

3737 2.52.5

Molar Molar relationrelation

-3.0-3.0 2.62.6www.indiandentalacademy.com

Amount of abnormality, or deviation is Amount of abnormality, or deviation is calculated by :calculated by :

V-CNV-CN SDSD


• Cephalometric analysis was conducted at Cephalometric analysis was conducted at baseline and 7 years for 40 children (20 girls, baseline and 7 years for 40 children (20 girls, 20 boys) who received no orthodontic 20 boys) who received no orthodontic treatment. Ricketts’ long-range prediction was treatment. Ricketts’ long-range prediction was performed from baseline cephalograms and performed from baseline cephalograms and compared with actual growth 7 years later. compared with actual growth 7 years later. Twenty-one cephalometric (12 angular and 9 Twenty-one cephalometric (12 angular and 9 linear) parameters were measured on actual linear) parameters were measured on actual and predicted tracings. The Pearson and predicted tracings. The Pearson correlation coefficient was used to evaluate correlation coefficient was used to evaluate relationships between the “predicted” and relationships between the “predicted” and “actual” measurements. “actual” measurements.

• There was a higher level of correlation for There was a higher level of correlation for growth prediction in girls growth prediction in girls

Evaluation of Ricketts’ long-range Evaluation of Ricketts’ long-range growth prediction in Turkish growth prediction in Turkish

childrenchildren


• The baseline average age was 9.2 ± 0.82 years The baseline average age was 9.2 ± 0.82 years for girls and 9.3 ± 0.92 years for boys for girls and 9.3 ± 0.92 years for boys

• Linear measurements: 1, Convexity; 2, Linear measurements: 1, Convexity; 2, Condylion-Point A; 3, Condylion-Gnathion; 4, Condylion-Point A; 3, Condylion-Gnathion; 4, Lower lip to E plane; 5, Upper lip length; 6, Lower lip to E plane; 5, Upper lip length; 6, Cranial length (anterior) (CC-Na); 7, Ramus Cranial length (anterior) (CC-Na); 7, Ramus height (CF-Go); 8, Porion to PTV; 9, Corpus height (CF-Go); 8, Porion to PTV; 9, Corpus length (Xi-Pm). length (Xi-Pm).

• Angular measurements: 1, Lower face height; Angular measurements: 1, Lower face height; 2, Nasolabial angle; 3, Facial depth; 4, Facial 2, Nasolabial angle; 3, Facial depth; 4, Facial axis; 5, Maxillary depth; 6, Maxillary height; 7, axis; 5, Maxillary depth; 6, Maxillary height; 7, Palatal plane-FH plane; 8, Mandibular plane-FH Palatal plane-FH plane; 8, Mandibular plane-FH plane; 9, BNA angle; 10, Cranial deflection; 11, plane; 9, BNA angle; 10, Cranial deflection; 11, Ramus-Xi position; 12, Mandibular arc angle. Ramus-Xi position; 12, Mandibular arc angle.


Ricketts’ long-range growth prediction applied Ricketts’ long-range growth prediction applied to Turkish children showed statistically to Turkish children showed statistically significantly higher correlations between significantly higher correlations between predicted and actual measurements in: predicted and actual measurements in:

• Convexity, lower face height, condylion, point Convexity, lower face height, condylion, point A, upper lip length, facial depth, facial axis, A, upper lip length, facial depth, facial axis, palatal plane-FH plane angle, mandibular palatal plane-FH plane angle, mandibular plane-FH plane angle, ramus height, and plane-FH plane angle, ramus height, and mandibular arc angle in girls mandibular arc angle in girls

• Lower face height, nasolabial angle, porion to Lower face height, nasolabial angle, porion to PTV, ramus-Xi position, cranial deflection, PTV, ramus-Xi position, cranial deflection, condylion-point A, lower lip-E plane, facial axis, condylion-point A, lower lip-E plane, facial axis, BNA angle, and mandibular arc angle in boys.BNA angle, and mandibular arc angle in boys.



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growth prediction2 / orthodontic courses by indian dental academy

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