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GROWTH ASSESSMENT & ITS CLINICAL SIGNIFICANCE

CONTENTS • • • • • • • • •

Introduction Types of growth data Methods of gathering growth data Evaluation of growth data Basic tenets of growth Growth analysis by superimposition technique Growth assessment parameters Clinical implications conclusion

INTRODUCTION

GROWTH : In biology, growth is increase in size or Mass accompanying normal development . The assessment of craniofacial structures forms a part of Dentistry & in various other disciplines. each person has a unique growth pattern that is influenced by their genetic make up and as well as external environment factors such as function, disease, habits & orthodontic treatment.

TYPES OF GROWTH DATA • DATA :a collective recording of observations either numerical or otherwise is called as ‘data’. • Main source of data :surveys , experiments ,records • Qualitative : sex ,malocclusion, cavity

• Quantitative : like arch length, arch width, flouride concentration in water supply

• Types of growth data: a) Direct data: size of teeth – Boley’s guage b) Indirect growth measurements – photographs dental casts ,cephalograms c) Derived data - by comparing atleast two other measurements:

METHODS OF GATHERING GROWTH DATA

• LONGITUDINAL STUDIES: Measurement made of the same person or group at regular intervals through time are longitudinal measurements.

• Advantages:  Studying the natural history of disease &its outcome.  Specific developmental pattern of an individual can be studied.

• Disadvantages:  Time  Expense  Attrition

• CROSS-SECTIONAL STUDIES measurement made of different individuals or different samples & studied at different periods Advantages:  Quicker  Allows repeating of studies more rapidly  Less costly

• SEMILONGITUDINAL STUDIES

METHODS FOR STUDYING PHYSICAL GROWH • Measurement approach Craniometry Anthropometry cephalometry

• Experimental approach Vital staining Implant radiography

• Others Electromyography Natural markers Radio isotopes Comparitive anatomy Genetic studies • Craniometry : originally used to study the Neanderthal & Cromagnon peoples skulls , found in European caves in 18 & 19 century

• ANTHROPOMETRY:  various landmarks established in studies of dry skull are measured in living individuals simply by using soft tissue points overlying these bony landmarks.  Farkas in 1987 provided new data for the human facial proportions and change in time

• CEPHALOMETRIC RADIOLOGY: In 1931 ,Boardbent in U.S.A & Hofrath in Germany simultaneously presented a standardized cephalometric technique using cephalostat. Allows a direct measurement of bony skeletal dimensions.  Growth studies can be done by superimposing a tracing / digital model of a later cephalogram on an earlier one. Disadvantage: it produces a 2-dimensionalrepresentationof a 3dimensional structure.

Purpose of Cephalometrics • Study craniofacial growth • Diagnosis • Planning orthodontic treatment • Evaluation of treated cases

LANDMARKS

GROWTH ANALYSIS BY SUPERIMPOSITION TECHNIQUE • Sella tursica & the cribriform plate remain unchanged after the fifth year of life. • Growth changes of facial skeleton can be evaluated by superimposing cephalometric radiographs on these stable structures • The following superimposition approach offers a sound & practical way of incorporating these structures in evaluation of facial growth.

• T-point – the most superior point of anterior wall of sella tursica C-point – the most • anterior point of cribriform plate at junction with nasal bone.’nasion’ may be used if C-point is not detectable L-point – the most • inferior point of sellatursica

• TC line a solid formation is provided through the shape of triangle • Cephalometric radiographs are taken at the age of 9 / 10 yrs / at the initial visit at the office and at least 6 months after the initial visit, • On super imposition two triangles ,the lower sides of triangle may not necessarily fit right on top of each other. • G- line A line connecting the T-point with gnathion, used as growth line.

• Advantage:  In diagnosis of abnormal skeletal development in both dimensions • Finally in evaluating the patient’s growth, the clinician ought not to ignore the nose.

• Class I subjects – straight nose • Class II subjects –more pronounced elevation of nasal bridge. • Class III subjects – concave configuration of nose along the dorsum • Very small increments of growth is noticed between the ages of 18 – 22 yrs

AUTOMATIC CEPHALOMETRIC ANALYSIS • Two approaches may be used to perform a cephalometric analysis a) manual •

approach

b) computer aided approach

conclusion

• automatic landmarking is the first & last step in development of a completely automatic cephalometric analysis. • Four catagories based on techniques / combination of techniques have been employed.

• • • •

Image filtering plus knowledge based Model based approaches Soft computing approaches Hybrid approaches

 The systems described are not accurate enough to allow their use in clinical purpose as errors in landmark detection were greater than those expected with manual tracing. ( The angle Orthodontist vol 78,1,jan 2008 ,R.R.J COUSLEY,E.G.RANT et al )

• THREE DIMENSIONAL IMAGING:  Computed axial tomography allows 3-D reconstruction of cranium, face.

• ANALYSIS OF MEASUREMENT DATA:  Both anthropometric and cephalometric data can be expressed cross-sectionally rather than longitudinally

Experimental studies • VITAL STAINING: Originated by the great english anatomist ‘John Hunter’ in 18 century.  Skeletal growth can be assessed using this technique  Here,dyes stain mineralising tissues are injected in the bone and teeth & can be later detected after sacrificing the animal.

• Dyes :alizarin – 1936 by ‘Belchier’ Alizarin red Acid alizarin blue Trypton blue Tetracycline Lead acetate

• IMPLANT RADIOGRAPHY:• 1969 by Arne Bjork.  provides imporatant new information about the growth pattern  metallic implants are usually very tiny about 1.5mm in length.0.5mm in diameter& are made of tantalum

Implant sites

• MAXILLA

• MANDIBLE

 Hard palate behind primary canines

 Anterior aspect of symphysis

 Below anterior nasal spine

 2 pins on right side of mandibular body

 Two implants on either sides of zygomatic process of maxilla

 One pin on external aspect of right ramus at the level of occlusal surface of molars.

 Borders between the hard palate medial to I molar& alveolar process

• Electromyography:

allows the action potentials of muscles of mastication to be correlated with morphological data & normalisation of muscle function in the treatment of malocclusion

• Natural markers:

There is a persistance of certain developmental features of bone, which are used as natural markers. eg : trabaculae, nutrient canals, lines of arrested growth can be used for reference to study bone deposition, resorption ,remodeling. .

Radio-isotopes: • used as in vivo markers for studying bone growth • Growth is measured by means of Geiger counters / auto radiographic techniques. Tc-99 detects areas of rapid bone growth in humans. ca-45 K -32

BASIC TENETS OF GROWTH • PATTERN: means arrangement of parts, values or events.

 Clinical implication: In Dentistry, use of word pattern has both morphologic & developmental application.

• VARIABILITY: it is the law of nature, because of infinite number of genetic possibilities. • Variability may be demonstrated in many ways. • In physical growth ,variability is demonstrated by the use of statistics.

• STATISTICS: MEAN (average of values) MEDIAN (value midway between greatest & smallest measurements. MODE STANDARD DEVIATION

• TIMING: The timing of developmental events is largely under genetic control yet altered by the environment.

•

There are sex related differences in the timing of many growth phenomena. usually,girls precede boys.

DIFFERENTIAL GROWTH • The concept of differential growth is based upon the observation that various structures of the body normally grow at different rates from birth to maturity. As a result, • each part of the body may contribute unequally to total size attainment at different points in time

• Significant and marked differences in the rate of growth within the same individual are uniformly evident. The changes that occur do not appear to be uniform and do not occur simultaneously. • At birth, the infant skull consists of about 45 bony elements separated by cartilage or connective tissue. This number is reduced to 22 bones in the adult after completion of ossification. • Fourteen of these bones are in the face, and the remaining eight form the cranium.

• Importance • The practical significance of the prediction process is to enable the dentist to predict the future facial adolescent spurt, • thereby enabling him to know the successful time for orthodontic treatment. • This is of particular significance when skeletal discrepancy is present, a favorable growth pattern may facilitate

SCAMMONS GROWTH CURVE 1.Lymphoid 2.Neural 3.Somatic 4.Genetic Lymphoid tissue - rapid proliferation-200% adult size

Neural tissue - rapid proliferation-6-7 yrs (adult size)

• Pattern of growth in man – Tanner(1962)

• CEPHALO-CAUDAL GROWTH CURVE : simply means that there is an axis of increased growth extending from head towards the feet. a comparision of body proportion between prenatal & post natal life reveals that post natal growth of regions of body that are away from the hypophysis.

Body proportion 1.Midpoint of stature 2 months –chest 2.At birth – above the umbilicus 3.Adult – pubic symphysis region 4.At birth 22% of body area is covered by head  decreases to 13% at 12 yrs 10% in adult

• Chilander et al(1985)

GROWTH SPURTS • Human growth is not a steady & uniform process of acceleration • There are periods of sudden rapid increase,which are termed as growth spurts.

Growth spurts Name of the spurt

Female

Male

Infantile / childhood growth spurt.

3yrs

3 yrs

Mixed dentition / juvenile growth spurt.

6-7 yrs

7-9 yrs

Pre-pubertal / 11-12yrs 14-15yrs adolescent growth spurt

a)Just before birth b)One year after birth c)Mixed dentition growth spurt  Boys- 8 -11yrs  Girls- 7 -9 yrs d)Adolescent growth spurt  Boys- 14 –16 yrs  Girls – 11- 13 yrs

• Growth in boys and girls (modified from Bjork 1975)

• Significance of growth spurt: 1.To differentiate whether growth changes are normal / pathologic. 2.Treatment of skeletal discrepancies ,if carried out in mixed dentition, more advantageous eg:appliance techniques like functional appliances &extraoral traction 3.Orthognathic surgeries should be carried out after the spurt.

FUNCTIONAL APPLIANCE THERAPY IN CONJUCYION WITH GROWTH HARMONE TREARMENT(T.I DAVIS,P.H .W RAYNER.JOURNAL OF ORTHODONTICS,VOL 22 1995

• The presented case is an eg :of Turners syndrome in which affected individuals do not have pubertal growth spurt and HGH, ethinyloestrodiol are needed to induce the spurt. without appropriate harmone administration it seems unlikely that a successful orthodontic result could have been achieved, particularly in active treatment period of 10 months.

GROWTH ASSESSMENT PARAMETERS

• ‘KROGMAN’ defines five ages of childhood.  Chronological age  Biologic age  Morphologic age  Skeletal age  Dental age

 Behavioural age  Mental age  Self-concept age

• According to singh: Neural age Physiological & biochemical age Mental age chronological age Dental age Sexual age

• CHRONOLOGICAL AGE: It is defined as age measured by years lived since birth. it is a poor indicator of maturity as it provides little validity for identifying the stages of development progression through adolescence to adulthood.

• SOMATOTYPIC AGE:  sheldon divided into 3 types

1.ectomorph – tall,thin ,fragile 2.Endomorph – stocky, abundant fat, digestive viscera highly developed 3.Mesomorph – upright ,sturdy & athletic ,

Growth charts • Normal growth in children can be explained in several ways. 1.Quantitatively 2.Qualitatively 3.Genetically determined process

• Growth charts attempt to describe these differing patterns of growth.

•

Percentile curves  derived from a normal distribution curve .the median is the 50th percentile.

 50% of population is above & 50% of a normal group of children is below this line.

• B) standard deviation charts: based upon the scatter of observations around a mean value.

Three growth charts are available. 1.Height Vs age chart: 2.Linear growth velocity Vs age chart 3.Child height to the mid-parental height.

• Growth charts can be used to follow a child over time to evaluate ,whether there is unexpected change in growth pattern . • Height has been employed as a convenient determinant of developmental age.

Predicting adult height & weight BOYS :2×height at 8 yrs =adult height GIRLS :2×height at 7.5 yrs= adult height BOYS :5×weight at 2 yrs =adult weight GIRLS :5×weight at 1.5 yrs =adult weight

PREDICTING ADULT HEIGHT AND WEIGHT AGE INCREMENT HEIGHT BIRTH 0–6 months

1 inch / month

20inches 26inches

6 – 12 months

0.5 inch / month

32inches

1-7 years

3 inches / year

50inches

8 – 15

1 inch / year

62inches

AGE BIRTH

INCREMENT -

WEIGHT to 8 lbs

0–4 months

2 lbs / month

15 – 16 lbs

4 – 12 months

2 lbs / month

23 – 24 lbs

1–2 years

0.5 lbs / year

29 – 30 lbs

2 – 10 yrs

5 lbs / year

69 – 70 lbs

• Dental age: the dental age is estimated by comparing the dental development status in a person of unknown age with published dental development surveys.

DIFFERENT METHODS FOR ASSSESSING DENTAL AGE  Gron & Moore method  Gustafson & Koch method  Glieser & Hunter(1955): first to advocate the calcification as a more meaningful indication of somatic maturation than its clinical emergence. • Demirijan:(1973):calcification of the tip of the cusp to closure of the apex closure. 8 stages: (A – H) 0 – for no calcification.

• MENTAL AGE: it is thus an index of maturation of mind,like the radiological age, that depends on many intrinsic &environmental factors. concept of intelligence co-efficient , mental age expressed as a percentage of chronological age

• NEURAL AGE: helps us to understand that the patient is mentally developed to understand the need for treatment &to what extent could he / she would be able to cooperate.

• PHYSIOLOGICAL AGE: Girls show a spurt in systolic blood pressure which occurs earlier than the corresponding spurt in the male. in plasma , organic phosphate shows a steady fall from the high levels of childhood to reach adult figures by the age of 15 in girls and 17 in boys . A more promising index is the ratio of creatine to creatinine.

SEXUAL AGE

MALES: 1.accelaration of growth of the testes & scrotum. 2.appearance of pubic hair. 3.enlargement of penis 4.height spurt 5.appearance of facial & axillary hair 6.enlargement of larynx

• Females  Appearance of breast buds & pubic hair  broadening of hips  Menarche, occurs almost after the maximal height.

FACIAL AGE • The ultimate goal of developmental growth assessment is the facial age

 Measurements for assessing craniofacial developments are :  Head circumference  Eye measurements inter canthal inter pupillary outer canthal  Ear length  philtrum length  Width of commissures

Change in facial proportion  Increase in facial proportion is seen as:         

Infancy to adolescence, Increase in size of dental arches Increase in size of muscles of mastication Growth of alveolar process Increase in maxilla Increase in mandible Nasal area Enlargements of orbits , Expansion of ethmoid &sphenoid

• NANDA Growth of the face in general tends to be maximal slightly later than the spurt in body height. • TOFANI Mandibular growth of females at puberty exhibited a spurt occuring 10 months before menarche in early maturing females. • HUNTER 57% of maximal facial increments occurred at the same time as maximum growth in height

SKELETAL AGE • Stanecu-1977 • Basis for skeletal age assessment

• Methods to assess skeletal maturation: 1.Handwrist radiographs 2.Cervical vertebrae 3.Clinical & radiographic examination of different stages of tooth development

REGIONS USED FOR AGE ASSESSMENT HEAD & NECK

SKULL , CERVICAL VERTEBRAE

UPPER LIMB

SHOULDER JOINT-SCAPULA ,HAND WRIST

LOWER LIMB

FEMUR &HUMERUS HIP JOINT,KNEE,ANKLE,FOOTTARSALS,PHALANGES

• ANATOMY OF HANDWRIST: • Distal ends of long bones of fore arm • Carpals proximal row distal row • Metacarpals • phalanges

INDICATIONS • In patients who exhibit major discrepency between dental & chronological age. • Determination of skeletal maturity prior to treatment of skeletal malocclusion • To assess the skeletal age in a patient whose growth is affected by infections • To predict the pubertal growth spurt • Valuable aid in research aimed at studying the role of heredity, environment, nutrition

RADIOLOGICL ASSESSMENT OF PREDICTION OF SKELETAL GROWTH • • • • • • •

Greulich & pyle method Bjork , grave and Brown Fisherman Singer’s assessment(1980) Hagg & Taranger method Bjork – ulna sesmoid centre as an indicator. Grave - pisiform , hamate, sesmoid bone

Correlation of skeletal maturation with pubertal growth spurt • HAGG & PANCHERZ – at puberty the spurt in growth in body height is accompanied by an increase in growth rate of jaws. • BJORK & HELM 1967 – onset of adductor sesmoid ossification & beginning of maximum growth period. • CHERTKOW 1980 – correlation between the growth spurt ossification and mineralisation of lower canine teeth.

SKELETAL MATURATION EVALUATION BY USING CERVICAL VERTEBRAE MATURITY INDICTORS • Hassel & Farman • Shapes of vertebral bodies of C3& C4 vertebrae changed . • The increasing in vertical height is associated with increase in skeletal maturity

RELATIONSHIP BETWEEN DENTAL AND SKELETAL MATURITY IN TURKISH SUBJECTS • The appearance of each skeletal age is consistently earlier in females than in males except for stage 9 • In Turkish subjects,tooth sequence in order of lowest to highest correlation

• FEMALES & males third molars canines first premolar second premolar second molar

• Findings of this study indicates that in children of Turkish origin the completion of roots formation of canines & first premolar may be used as maturity indicators of pubertal growth spurt • It is appropriate to put these skeletal & dental maturation relation ships into daily orthodontic practise, when treating a Turkish patients (The Angle Orthodontist 74,5,2004 oct).(Tancon uysal,zafer sari et al.)

Growth prediction • According to Bjork:  Longitudinal  Metric  structural

• Longitudinal Approach ‘Tweed’ • Type-A: growth of middle &lower face proceeds in unison with vertical &horizontal dimensions in being approximately equal no treatment is indicated. • Type-A subdivision Type-B: middle face grows downwards & forward more rapidly than lower face. poor prognosis ,point B will not catch up with the point A. • Type-B subdivision:

• Type-C :maxilla & mandible grow forwards and downwards with the mandible growing forwards more rapidly than the maxilla. • Type-C subdivision:

• This approach is accurate only when it is performed retrospectively but not prospectively therefore, it can be concluded that longitudinal approach is not an accurate method of predicting future dentofacial changes

• STRUCTURAL APPROACH: Prediction for mandibular growth direction Bjork. Bjork listed seven areas on cephalograms that should be evaluated to help predict future mandibular growth direction.

1.inclination of condyle. 2.curvature of mandibular canal 3.iclination of symphysis 4.shape of lower border of mandible 5.inter incisal angle. 6.inter premolar / molar angles 7.Anterior lower face height

• SKIELLER,BJORK,LINDE HANSEN  attempted to refine this prediction by quantifying it. • four variables: 1.ratio of posterior / anterior facial face heights. 2.inter molar angle 3.shape of lower border of mandible 4.inclinationof symphysis Conclusion:all the three approaches have limited clinical value.

• METRIC APPROACH:  Consists of measuring different structures on a single X-ray film then relating these measurements to future growth changes.

COMPUTERISED PREDICTION METHODS • The biggest advantage of computer technology is that it facilities testing & applying more complex formulations to growth prediction. • ‘Ricketts’ introduced his method of computer analysis based on the concept of the cubic root combined with a vast clinical experience.

• Greenberg & Johnston tested these computer predictions. • Comparision were made between three types of calculations. 1.computer forecast of changes between10 & 15 yrs of age group on the 20 cases 2.the actual changes that occur in same 20 cases 3.adding the average changes of remaining 80 .

• Concluded as there were no significant differences in accuracy between computer prediction & those based on simple addition of average changes.

• Cangialosi et al  computer programe using pre treatment & post treatment cephalograms • Growth forecast from computer is compared with the manual method • Computer analysis came close to the 4 variables & by manual method close to three variables • Predicting the skeletal & soft tissue changes was much less accurate.

• Conclusion:

overall changes in size & relationship

•

of human face ,in general difficult to accurately predict for an individual at this time. because, the changes are under the influence of combined & complex hard-topredict,genetic,environmental factors.the situation is even more complex ,because we are using two dimensional cephalograms to evaluate a three dimensional face.

CLINICAL IMPLICATIONS • Inaccurate Data: Many apparent growth abnormalities are the result of errors in the measurement of growth parameters or errors generated when plotting growth parameters on growth curves

• . In cases of potential growth disturbance, careful attention to rigorous methods of measurement is: • Children less than two years of age should be weighed without clothing. Older children can be weighed in lightweight clothing without shoes

• . Current assessments of growth focus heavily on the use of growth curves developed by the National Center for Health Statistics in the 1960s and 1970s. • Children whose growth parameters are at the extremes of the growth curve but who have normal growth rates are likely to be healthy. • Time as a Tool: Time is the primary assessment tool available to the family physician.

• Common Pathologic Etiologies of Weight Disorders

Increased weight : • Endocrine disorders • Hypothyroidism • Excess production of cortisol (Cushing's disease) • Thalamic or pituitary disorders • Genetic disorders

Decreased weight • Under nutrition • Psychosocial deprivation • Hypothyroidism • Iron deficiency • Failure of a major organ system • Lead intoxication • HIV infection • Immune deficiencies • Zinc deficiency • Inborn errors of metabolism

• Common Pathologic Etiologies of Height Disorders • Increased height : • Excess production of growth hormone • Hyperthyroidism • Klinefelter's syndrome • Marfan syndrome • Homocystinuria

Decreased height Growth hormone deficiency Hypothyroidism Chronic anemia (Turner's syndrome) Failure of a major organ system (especially gastrointestinal, renal, pulmonary or cardiovascular) • Skeletal dysplasia/rickets • Psychosocial deprivation • • • • • •

Evaluation of the patient with an abnormal head size. • examination and developmental status . • Associated physical findings such as a bulging fontanelle or split sutures, neurologic abnormalities or delays in developmental status warrant evaluation

• Common Pathologic Etiologies of Cranial Disorders • Increased head size • Hydrocephalus • Megalencephaly • Primary • Secondary to associated disease of the central nervous system such as neurofibromatosis or tuberous sclerosis. • Secondary to metabolic storage disease such as Krabbe's disease

• Decreased head size Craniosynostosis • Prenatal insult • Maternal drug or alcohol abuse • Maternal infection • Complications of pregnancy/birth • Chromosome defects

• The clinical implications regarding maxillo – mandibular relation ships: Role of growth spurts Role of skeletal maturation Role of direction of growth Effect of alveolar growth on the placement of implants.

VARIOUS CHANGES OF DEVELOPMENT THAT ARE OF INTEREST TO A DENTIST (5 -25YRS) • Changes in maxillary length: 40%, 40% 20% males. 50%,30%,20% females changes in mandibular length: 34%,39%,27% males 48%,41%,11% females. maxillo- mandibular relationship:

• changes in various other factor  facial type : vertical relation ship is more pronounced.  concept of genetic make up

 effect of environment

conclusion • There are least five components to be dealt with the prediction of cranio facial changes:  direction  Magnitude  Timing  Rate of change  Effects of treatment

• In planning & carrying out orthodontic treatment it would be of value in predicting the final form and size of the face & jaws. after growth has ceased. • The prediction of skeletal height has been well documented. • Individual variation reduces the accuracy of prediction. • The prediction of facial form is more complex & inevitably less accurate. • Various growth parameters for prediction although they received support from different investigators , there are possibilities of measurement errors ,which limit all forecast on growth & development, because of these dificulties, current growth prediction are of limited value.

REFERENCES • Scientific foundations & clinical research –Stewart • Handbook of orthodontics – Robert .e. moyers, iv edition • Orthodontics –principles & practice –Graber t.m iii edition • Orthodontics for dental students – J.H.Gardiner,B.C.Leighton, J.K.Luffingham, Ashima valiatha • Textbook of orthodontics – Mire.Bishara • Textbook of orthodontics – Gurkeerat singh • Contemporary orthodontics –Profitt,fourth edition.

• Contemporary treatment of dentofacial deformity –Profitt White Server –south Asia Edition. • Atlas of Advanced Orthodontics – Viazis • Orthodontics the art & science –Bhalaji • Textbook of pedodontics – shoba tandon • Essentials ofpreventive & community dentistry – soben peter.III edition. • A Textbook of orthodontics – T.D.Foster.iii edition • The Angle Orthodontist vol 74,5,2004 oct • The Angle Orthodontist vol 78,1,2008 jan • Journal Of Orthodontics,VOL 22 1995

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