Assessment of Growth-OrTHO / orthodontic courses by Indian dental academy

Leader in continuing dental educationwww.indiandentalacademy.com

INDIAN DENTAL ACADEMY

www.indiandentalacademy.com

METHODS OF OSSIFICATIONAND ASSESSMENT OF BONE GROWTHRECENT ADVANCES


INTRODUCTION As with all practitioners in health arts,an Orthodontists primary objective is to describe and diagnose malocclusion he/she wishes to treat in confirmity with the primary dictim of medicine ,primum,non nocere (first ,do no harm)irst ,do no harm)

The diagnosis can dictate the treatment The diagnosis can dictate the treatment objectives and mechanotheraphy for a particular objectives and mechanotheraphy for a particular patient.patient.

The ability to predict patient’s facial growth The ability to predict patient’s facial growth early in life would enable the clinician to establish a early in life would enable the clinician to establish a correct diagnosis and identify the appropriate correct diagnosis and identify the appropriate treatmenttreatment


METHODS OF

OSSIFICATION


BONE FORMED BY TWO MECHANISMS

Intramembranous ossification

Endochondral ossification


INTRAMEMBRANEOUS OSSIFICATIONWithin membranous,condensed plateof mesenchymal cellsMesenchymal cells lay down collagen – membrane formed.At initial site of ossification mesenchymal cells differentiate into osteoblastsOsteoblasts deposit osteoidOsteoblasts located in lacunae within matrixCollagen fibres – no preffered orientation – Woven bone


Osteoid calcifies – primitive trabecular bone

Through reorganisation primitive trabecular bone & compact bone converted to mature bone


ENDOCHONDRAL OSSIFICATIONFormed by transformation of cartilage “bone models”

Mesenchymal condensation – cells become chondroblasts,cells on surface of cartilage form perichondrium

Intercellular substance calcify , nutrition cut off , cells die ,PRIMARY AREOLAE

Periosteal bud invades cartilage model & progenitor cells enter cartilage


Periasteal bud eats away the calaified matrix- large cavities – SECONDARY AREOLAE

Osteogenic cells become osteoblasts , lay down osteoid

Bone deposited– lamellar bone – primary ossification centre

Secondary ossification centre – future epiphysis


Periosteal collar – around shaft of cartilage model – woven bone


Distinct zones close to the zone of ossifying cartilage

Reserve cartilage – farthest from zone of ossificationZone of chondrocyte proliferationZone of cartilage maturation and hypertrophyZone of cartilage calcification


Between epiphysis and diaphysis – epiphyseal plate

Epiphyseal plate – basis for rapid growth of length of bones

Removed by continued production of bone from diaphyseal side


Bone formation & resorption go hand in hand

1st deposited trabecular bone removed as zone of ossification moves in direction of future epiphysis

Creates marrow cavity of the bones

Bone removed from endosteal surface & deposited on periosteal surface of compact bone which forms diaphysis

This results in growth of diameter of bone


REORGANISATION OF BONE

Change in size & shape of bone during growth

Key players – osteoblasts & osteoclasts

Cutting cone-Head of osteoclasts,Tail of osteoblasts

New secondary osteons


METHODS OF ASSESSMENTDirect measurements

Osteometryvital stainingimplant markershistologic method

Indirect measurements Photographsmodelsradiographswww.indiandentalacademy.co

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Indirect measurments in combination X-ray + implantsX-ray + metaphyseal bandsAutoradiograhs

3D facial measurementsStereophotogrammetrySassomis physioprintRabey’s morphanalysisHolographyMoire topographyContour photographywww.indiandentalacademy.co

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MEASUREMENT APPROACHES

Craniometry Anthropometry Animal experiments-1.Vital staining 2.Histology 3.Split line technique 4.Implants Radioactive tracers Auto radiographs Cephalometric roentgenography Photocephalometry Computerised cephalometry


Roentgen stereophotogrammetryMedical photogrammetryContour photographySilhouette methodStudy models Facial masksLaminagraphyElectromyography

Xeroradiography for cephalometric analysis


Measurements of landmarks on skull

Dried bones used

Static cross-sectional study

CRANIOMETRY


ANTHROPOMETRY Measure skeletal dimensions on living subjects. Camphor,Morton ,Broca Longitudinal data John Hunter-first to apply anthropometry using

mandible Mandible lengthened posteriorly Coronoid and condyle superiorly Resorption along anterior border of ramus Deposition along posterior border Increase in width of ramus


ANIMAL EXPERIMENTS

VITAL STAINING

Madder feeding

Leninus(1567)-staining property of root in bone

Belchier(1736)-accurate account

Duhannel(1742)-only newly formed bone stained

Hunter-wide alternate red & white band of bone

Brash – 5 pigs of different agewww.indiandentalacademy.co

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Alizarin red injections

Reveals rate,procedure,nature of calcification.Single i.p /i.v -2%solution of alizarin redReacts strongly with calcium at sites of calcification.Invasive studyGround sections usedWet specimen is ground,cleaned ,dehydrated , xylene treated and mounted.


HISTOLOGYQualitative processes responsible for growthDirect measurements-Optical superimposition Indirect-Micro photographsEnlow-reconstructed 2Dimages of mandibleSite ,direction &pattern of bone growthLocalisation of enzymes,glycogen&glycoproteinsOsteoclasts – Bone resorptionOsteoblasts – Bone deposition



http://www.medes.fr/Eristo/Osteoporosis/OsteoCBImage.html

SPLIT LINE TECHNIQUE

Benninghoff(1925)-superficial trabecular bone pattern

Bones decalcified,penetrated with needle

Indian ink diffuses to fix fine trabecular bone pattern


IMPLANTSDuhamel(1742) – silver styletsHunter(1770) – lead shots in tibia of pigsAu,Ag,Amalgam,SS,Vitalium,Tantalum-pins,clips,pegs,screws,plates,wires1st dental study – Humphery(1864) – pig mandible – wire loops around ramus

- resorption in anterior border

-deposition in posterior border www.indiandentalacademy.co

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Indirect studies – using x-rays

Grans Robinson,Sarnath – Silver amalgam implants

Bjork – Tantalum pins & wires

- serial x-rays taken

Adv: - no interference with diet

- non invasive,

- new bone formation&resorption measured

Disadv: - sum total is demonstrated

- intervening changes not revealedwww.indiandentalacademy.com

RADIOACTIVE TRACERS

Radiophosphorous,RadioNa,RadioCa,Strontium,RaFluoride,RaChloride,Iodine,Carbon,Plutonium, Americanum,Gallium

Incorporated into tissue as a sort of vital stain.

i.v.injection of isotope,detected by weak radiation it emits


AUTORADIOGRAPHS Placing tissue of an animal injected with

radioactive substance close to a photographic emulsion

Exposed to radiation in dark Distribution of radioactive material-dark.


ROENTGENOGRAPHS

Superimposition of successive x-rays Krogman & Sassouni(1957)-measurments from

shadows of bone &soft tissue landmarks on radiographic images

1922-Paccini –Teleradiographic image 1912 -Tandler- x-ray film in Anthropometry Serial hand wrist x-rays to detect growth changes Greulich&Pyle/ Tanner&Whitehouse-comparing

the stages with standard norms-amount of growth left assessed.


CEPHALOMETRIC ROEOTGENOGRAPHY 1931-Broadbent &Hoffrath Krogman,Savara,Meridth,Popovitch,Bjork,& Woodside Longitudinal studies Stable anatomic base for superimposing Rate ,amount,&relative direction of bone growth Distinguish horizontal &vertical growth patterns Unilateral condylar hypoplasia-marked mandibular notching

on the affected side Does not reveal sites or mode of growth Solow &Kreiborg-Multiprojection cephalometry EDP(Electronic data processing) Disadv-2D representation of a 3D structure PACeph projection-Moorees,Moyers Chierici&Faber.


PHOTO CEPHALOMETRY

Superimposition of co-ordinated head films with photographsPhoto images on skin of patient-accurately superimposed on corresponding markers in a cephalogramAdv: Soft tissues seen


COMPUTERISED CEPHALOMETRICS

1970 in U.S.AComputer fed with all data regarding norms & standards of all analysisLess time consuming,increased reliability by double digitization & easy storage of information


XERORADIOGRAPH FOR CEPHALOMETRIC ANALYSIS

1971 Selenium containing plates in plastic cassette Reconstruction of cephalomatric planes

&points made on tracing paper applied over the picture

Adv:All densities displayed Edge enhancement effect


CONTOUR PHOTOGRAPHY

Cobb(1972),Lovesy (1974),Robertson(1976)

Light sectioning technique

Equal width grids projected on face producing contour pattern

Convex telecentric lenses are placed in paths of projected beams & of recording camera www.indiandentalacademy.co

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SILHOUETTE’S METHODLight projected on patient from a predetermined distanceShadow on a smooth ,fixed screenLontitudinal study


STUDY MODELS Duplication with plaster,thiokol,hydrocolloid,stone Permanent records,longtitudinal studies possible Model analysis done & growth changes measured

FACIAL MASKS Impression of face taken at regular intervals Standard measurements – Zygoma-zygoma, Gonion-Gonion.


LAMINAGRAPHY

Assess peri-chondroblastic activity of secondary cartilage in reaction to stress on mandibular condyle,by using lamina &examined under microscope


ELECTROMYOGRAPHYAssess electric potentials in response to external stimuli of muscle spindlesDeep & surface electrodesKinesograph-movements of muscle spindlesPrinciple – bone yields to muscle pressure Studying the role of muscle influence on bone growth Caliberated metre – records the potential elicited during movementsAmount needed to elicit response – amount of growth judged


SKELETAL INDICATORS OF MATURITY

Hand wrist radiographsCervical vertebraeCanine calcification


HAND WRIST RADIOGRAPHSP-A radiograph of left hand & wrist

Todd , followed by Greulich & Pyle – Atlas of standard hand & wrist films at various ages

Systematic comparison of left hand & wrist to atlas standards

Bones assessed in regular order

Each centre is given a skeletal age , an overall average age is determined

Good index of overall biologic maturationwww.indiandentalacademy.com

Tanner & Whitehouse method – “maturity points”,scores givenBjork – capping of epiphysis of 3rd middle phalanx closely related to P.H.V


GREULICH & PYLE METHOD –

Comparison with standard x-rays

TANNER & WHITEHOUSE METHOD –

“Maturity points”,scores given

ANTHROPOMETRIC METHOD

U/L Segment ratio www.indiandentalacademy.co

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Tanner & Whitehouse method3 methods

1.RUS

2.Carpal bone method

3.TW2 method – each growth centre – maturity rating on a scale of 8 ( A toH) except Radius ( A to I)

Numerical score for each centre

Total gives overall maturity ratingwww.indiandentalacademy.co

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OSSIFICATION OF ABDUCTOR SESAMOID & MP3

Taranger &HassSesamoid usually attained during acceleration period of pubertal growth spurtMP3 – third finger middle phalanx


Chapman – Standard size dental films to assess development of 1st metacarpal joint Abductor sesamoid ossification – beginning of adolescent spurt in heightBjork,Holm – 7 Maturational events -Bone development to growth velocity


CERVICAL VERTEBRAESato – appearance of epiphyseal plate of odontoid process – indicator of growth peak

Lampraski – atlas that stimulated morphologic changes in cervical vertebral bodies in puberty

Hassel & Farman , Garcia – Fernandez – pubertal growth based on cephalometric radiographs

O Rielly & Yaniello (1998) – increase in corpus length , ramus height & mandibular length during stages of cervical vertebral maturation


CANINE CALCIFICATION

Garn,Engstrom & co workers – relationship between tooth mineralisation & skeletal developmentMandibular canine - to estimate timing of pubertal growth spurtAssessed according to Demirjian’s stage of dental calcificationMaturity of mandibular canine is more closely related to PHV than other tooth


A.Initial cusp

B.Cusp coalesence

C.Crown ¾th formed

D.Formed upto CEJ

E.Root smallerthan crown

F.Root & crown equal

G. Apex still open

H.Fully erupted


MORPH ANALYSIS

Centroid-based pattern of orientationDental,skeletal & soft tissues identified by non-numeric graphic approachCGA-centro graphic analysis –cephalometric radiograph to demonstrate growth changesFacial centroid axis was formulated to provide a better , stable reference plane


CO-ORDINATE GRIDS FOR 3D FACIAL MEASURMENTSLeivesley(1983)Volumetric measurements & rectangular co-ordinatesTwo grids available-

Uniformly spaced grids with predetermined

interval

Proportionally spaced gridswww.indiandentalacademy.co

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Superimposition – measurement in those areas lacking natural landmark

Grid intersections – used to define artificial , constructed landmarks


FOURIER ANALYSIS

Mathematical method , allows quantitative analysis of shape and it’s changes

Reconstruct outlines , landmark identification and fourier analysis of these outlines through a set of equations enables detection of variations in soft tissues and growth changes over a period of time

www.indiandentalacademy.co

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NMR SPECTROSCOPY

New method of obtaining 3D cross sectional pictures of thin slices of human head - using resonance of hydrogen nucleiRadio tracers of P,Na,Mg - growth studies on non invasive plane


COMPUTER AIDED TOMOGRAPHY

Image of the subject is processed by a computer , assessing cranio facial growth and numerical investigations regarding growth


COMPUTER LASER SCAN SYSTEMSRegular cephalostat for taking cephalograms with specialised coated filmsHe & Ne Lasers - used to activateDelinate hard & soft tissues


LASERRapid 3D for facial morphology study

Scan face in 6 seconds,gives image in 4 min

Adv:contact free , data memory,rapidity

Dis adv:costlywww.indiandentalacademy.co

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DIGIGRAPH

Sonic digitizing probe

Pressing button – sound elicited & land mark recorded by microphone array

Dolphin imaging systems(California,USA)


Lighthly touching the probe to patient’s skin

Electronic circuitoryHead holder2 video camera


Ceph measurements recorded by microphone array in X-Y-Z co-ordinateCalculating time between sonic wave emission & detection


FINITE ELEMENT ANALYSISIn 1985, Melvin moss ,introduced a method to analyse a cephalogram that uses partial differential equations to asign loading values for intermediary points in irregular structures by dividing into a set of regular geometric shapesGenerate a mathematical matrix of transformation related to both size & shapeFinite element for analysis of serial,lateral cephalometric radiographsUseful tool for morphometric analysis in craniofacial biology


By reducing the structure to a group of appropriately connected small elements of known mechanical behaviour,the response of entire structure to loading can be estimated


ANTEGONIAL NOTCH FOR GROWTH PREDICTIONSinger , Mamandras & HunterPresence of prominent antegonial notch-arrested growth of mandibular condyles Apposition Resorption Forward rotating symphysis AngleBackward rotating Angle SymphysisSo deep antegonial notch – Backward rotating mandible.


FRONTAL SINUS & MANDIBULAR GROWTH PREDICTION(AJO DO 1991 DEC)Rassouw,Lombard & HarrisCorrelation between max & mand length, symphysis width,condylar length & frontal sinus on lateral cephFrontal sinus bud present at birth in ethmoid region Rapid growth to adult size at 12 yearsTunner-Annual height growth increments reached a plataeu at ages when frontal sinus enlargement ceasedwww.indiandentalacademy.co

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Brown,Molleson & Chinn – study on lateral cephThe surface area(sq.mm) of frontal sinus –assessed by summagraphic decoder linked to a microcomputerNegative ANB angle – small maxilla & large mandible coincided with large frontal sinusFrontal sinus size though influenced by external environment & muscle attachments is a valuable indicator of excessive mandibular growth.


ROENTGEN STEREOPHOTOGRAMMETRY

Selvik(1974)

Davidson,Hedley & Payne – 3D localisation procedures from radiopgraph

Bone markers – Tantalum spheres,balls or pins

Aromo,Selvik & Holst – implantation instruments with a needle & adjustable stop clock

2 markers – longitudinal growth registration

3 markers – kinetic studies

Growth is calculated from distancewww.indiandentalacademy.com

Distance changes - from 3D co-ordinates of implants using the 3D pythogorean theoremBiologic mechanism of growth – spatial

co-ordination from 2D film co-ordinates

RAD – below normal

New & exact information on skeletal growth

No technical problems – differential enlargement , definition of landmarks , image interpretation problems , orientation errors

Skull cephalostats avoidedwww.indiandentalacademy.com

CASMAS - COMPUTER AIDED SKELETAL MATURITY ASSESSMENT SYSTEM

Digital hand atlas with large set of normal set of hand & wrist images that reflect skeletal maturity , race , sex difference & current child developmentDigital hand atlas will be used for computer aided bone age assessment via webMedical university California designed and partially implemented a computer aided diagnostic system for web based bone age assessment


The system consists of digital hand atlas , a relational image data base & web based interfaceThe digital atlas is based on a large set of normal hand & wrist images with extracted bone objects & quantitative featuresThe image database uses a content based indexing to organise the hand images & their attributes & present to user in a structural wayAllows users to interact with hand image data base from browsersUsers can use a web browser to push a clinical hand image to CAD server for a bone age assessment


Quantitative features on the examined image, which can reflect the skeletal maturity will be extracted & compared with patterns from atlas database to assess the bone ageThe relevant reference images and the final assessment report will be sent back to user’s browser via web


THREE DIMENSIONAL FACIAL GROWTH STUDIED BY OPTICAL SURFACE SCANNINGThe optical scanner – rapid accurate data collection in 3DAssosiated software creates a visual image Dis adv – high costRecently,video-capture stereoscopic method of imaging2 pairs of stereo camera – curved facial structures are imaged


The system allows photo realistic image generation of the face that can be viewed from any directionStudy the 3D alterations in the facial morphology with increasing age


CONCLUSION Dynamics of growth is a complex process The Orthodontist , if he is to evaluate properly the role he plays in correcting malocclusion must have the opportunity to examine the conditions over which he has the least control , namely growth & development during correction of malocclusion With the use of the recent techniques available accurate information about growth can be obtained


REFERENCES1.Profitt – Contemporary Orthodontics2.White & Goaz – The Dental Radiology3. Athanasiou – Orthodontic Cephalometry4.Thomas Rakosi – Cephalometric Radiography5.Inderbir Singh – Textbook of human histology6.Hassel & Farman – Skeletal maturation evaluation using skeletal vertebra- AJO DO 1995,107,pg:58-667.Bernard G. Sarnath – Growth pattern of mandible – AJO DO 1986 pg:221-2338.Garcia – fernandez,The cervical vertebra as Maturational indicator- JCO April 19989.Leivesly – Reliability of Contour Photography for facial measurements- BJO 1983, pg:34-37

10.Tashinaro Mito & Sato – Cervical vertebral bone age in girls – AJO DO 2002,122,pg:380-38511.Hagg & Taranger – Maturity &Pubertal growth spurts – AJO 1982,82,pg:299-309

12.Nute & Moss – 3D facial growth studied by optical scanning – JO 2000 vol 27,pg:31-38


13.Chertkow – Tooth mineralisation as an indicator of the pubertal growth spurt – AJO DO 1980 ,pg:79-9114.Sato & Mito – An accurate method of predicting mandibular growth potential based on bone maturity – AJO DO 2001 , 120, pg :286-29015.Sierra – Assessment of dental & skeletal maturity – A new approach,AO 1987,pg:194 –20816.Abdul Khadher – The potential of dental didital Radiography in recording adductor sesamoid & MP3 – BJO 1999,VOL:26,291-29317.Kolodziej,southard – Evaluation of Ante gonial notch depth for growth prediction – AJO DO 2002,121,pg:357-36318.Melesio.r.Leite, O’Rielly – Skeletal assessment using 1sty , 2nd & 3rd fingers of hand – AJO DO – 1987,pg:492-49819.Sandro Coutinno – relationship between mandibular canine calcification stages & skeletal maturity – AJO DO 1993, pg:262 -268


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www.indiandentalacademy.comLeader in continuing dental education


Assessment of Growth-OrTHO / orthodontic courses by Indian dental academy

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