Role of cephalometry in orthdodontics

INTRODUCTIONINTRODUCTION
The discovery of X-rays led to the measurement of the headThe discovery of X-rays led to the measurement of the head
from shadows of bony and soft tissue landmarks on the roentgenographicfrom shadows of bony and soft tissue landmarks on the roentgenographic
image that came to be known as theimage that came to be known as the Roentgenographic CephalometryRoentgenographic Cephalometry..
For many years since the 1930’s spawned by the classic work ofFor many years since the 1930’s spawned by the classic work of
BroadbenBroadbentt andand HofrathHofrath in the United States and Germany respectively,in the United States and Germany respectively,
cephalometrics has enjoyed wide acceptance as an essential componentcephalometrics has enjoyed wide acceptance as an essential component
of the diagnostic phase for the more traditional forms of orthodonticof the diagnostic phase for the more traditional forms of orthodontic
treatment. Innumerable research works and papers have been publishedtreatment. Innumerable research works and papers have been published
in this field.in this field.
In more recent times, the importance of sophisticatedIn more recent times, the importance of sophisticated
cephalometric methods, often computerized, has become clearlycephalometric methods, often computerized, has become clearly
established as an indispensable diagnostic tool for the analysis andestablished as an indispensable diagnostic tool for the analysis and
correction of a wide range of craniofacial orthopedic problems.correction of a wide range of craniofacial orthopedic problems.
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DEFINITIONDEFINITION
Origin:Origin: ‘Cephalo’‘Cephalo’ means head andmeans head and ‘Metric’‘Metric’ is measurement.is measurement.
In oral surgery and orthodontics:In oral surgery and orthodontics:
11. “The scientific measurement of the bones of the cranium and. “The scientific measurement of the bones of the cranium and
face, utilizing a fixed, reproducible position for lateral radiographicface, utilizing a fixed, reproducible position for lateral radiographic
exposure of skull and facial bones”.exposure of skull and facial bones”.
22. “ A scientific study of the measurements of the head with. “ A scientific study of the measurements of the head with
relation to specific reference points; used for evaluation of facialrelation to specific reference points; used for evaluation of facial
growth and development, including soft tissue profile”.growth and development, including soft tissue profile”.

HISTORY OF CEPHALOMETRICSHISTORY OF CEPHALOMETRICS
InIn 17801780,, Petrus CamperPetrus Camper, probably the first to employ angles in, probably the first to employ angles in
measuring the face, oriented the skull on a horizontal from themeasuring the face, oriented the skull on a horizontal from the
middle ofmiddle of porus acusticusporus acusticus to a point below the nose. Craniostatsto a point below the nose. Craniostats
were designed to hold the skull in an oriented position to givewere designed to hold the skull in an oriented position to give
greater reliability to the measurements, and they were thegreater reliability to the measurements, and they were the
forerunners of the cephalostat or headholder. The dry skullforerunners of the cephalostat or headholder. The dry skull
measurements, craniometry, was done from countless aspects. Butmeasurements, craniometry, was done from countless aspects. But
these static and nonvital studies did not interest thethese static and nonvital studies did not interest the
orthodontists. With the application of these measurements toorthodontists. With the application of these measurements to
living subjects, their use in orthodontics was deemed important.living subjects, their use in orthodontics was deemed important.

At theAt the 18821882 meeting of the International Congress of Anthropologymeeting of the International Congress of Anthropology
in Frankfort, Germany,in Frankfort, Germany, Von Ihering’sVon Ihering’s lineline (drawn from the upper(drawn from the upper
margin of the external acoustic meatus to the lowest point of themargin of the external acoustic meatus to the lowest point of the
infraorbital margin) was accepted as a standard plane of orientation.infraorbital margin) was accepted as a standard plane of orientation.
This line is the forerunner of the Frankfurt Horizontal plane, which isThis line is the forerunner of the Frankfurt Horizontal plane, which is
the basis of the roentgenographic cephalometric orientation.the basis of the roentgenographic cephalometric orientation.
InIn 1895 Wilhelm Conrad Roentgen1895 Wilhelm Conrad Roentgen discovered X-rays. In the samediscovered X-rays. In the same
time periodtime period Milo HellmanMilo Hellman adopted techniques of physical anthropologyadopted techniques of physical anthropology
to orthodontic research followed by which skull radiographs came intoto orthodontic research followed by which skull radiographs came into
use.use.
InIn 19211921,, A.J. PaciniA.J. Pacini, presented the paper, presented the paper “Roentgen Ray“Roentgen Ray
Anthropometry of the Skull”Anthropometry of the Skull” which stated that the accuracy ofwhich stated that the accuracy of
roentgen ray anthropometry far surpassed ordinary anthropometry.roentgen ray anthropometry far surpassed ordinary anthropometry.
He aligned the subjects head so that the mid-sagittal plane wasHe aligned the subjects head so that the mid-sagittal plane was
parallel the film. A constant target-film distance of 2½ feet wasparallel the film. A constant target-film distance of 2½ feet was
employed and the central ray was directed one inch above and in frontemployed and the central ray was directed one inch above and in front
of the EAM.of the EAM.

In theIn the 1920’s1920’s,, B. Holly BroadbentB. Holly Broadbent of the USA worked with the anatomistof the USA worked with the anatomist
T. Wingate Todd, after his orthodontic training in the Angle school. HisT. Wingate Todd, after his orthodontic training in the Angle school. His
previous experience with profile roentgenography helped Broadbent designprevious experience with profile roentgenography helped Broadbent design
his roentgenographic craniostat. His success with this led him to thehis roentgenographic craniostat. His success with this led him to the
development of thedevelopment of the cephalostatcephalostat or head holder. Inor head holder. In FebFeb 19311931,, BroadbentBroadbent
presented his paper under the title “presented his paper under the title “A new X-ray technique and itsA new X-ray technique and its
applications to orthdodontics”,applications to orthdodontics”, describing roentgenographic cephalometry atdescribing roentgenographic cephalometry at
the mid winter meeting of the Chicago Dental Society. Further workthe mid winter meeting of the Chicago Dental Society. Further work
produced the roentgenographic cephalometer. It is a head positioning deviceproduced the roentgenographic cephalometer. It is a head positioning device
similar to a craniostat.similar to a craniostat.
Further more inFurther more in 19311931,, Herbert HofrathHerbert Hofrath published in the Germanpublished in the German
literature an article entitiledliterature an article entitiled “Importance of teleroentgenograms for the“Importance of teleroentgenograms for the
diagnosis of Jaw Abnormalities”.diagnosis of Jaw Abnormalities”. A 2M target distance was used. The X-rayA 2M target distance was used. The X-ray
tube was placed at one end of a long tube and at the other end was a devicetube was placed at one end of a long tube and at the other end was a device
carrying two pairs of crossed wires for the purpose of orienting the axis ray.carrying two pairs of crossed wires for the purpose of orienting the axis ray.
Hofrath’s method differed from that of Broadbent’s in that there wasHofrath’s method differed from that of Broadbent’s in that there was
littkle mention of a frontal view, the path of the central ray was not fixed inlittkle mention of a frontal view, the path of the central ray was not fixed in
relation to the head, there was no plane for superimposition andrelation to the head, there was no plane for superimposition and
considerable stress was laid on the recording of the soft tissue. Hisconsiderable stress was laid on the recording of the soft tissue. His
procedures had less refinement and precision than Broadbent.procedures had less refinement and precision than Broadbent.

TheThe University of IllinoisUniversity of Illinois and theand the University of ColoradoUniversity of Colorado were awere a
few early centers for cephalometric research. After the inventionfew early centers for cephalometric research. After the invention
of cephalometric radiograph,of cephalometric radiograph, Lucien de CostarLucien de Costar of Belgium was theof Belgium was the
first to publish an analysis based on the proportional relationshipsfirst to publish an analysis based on the proportional relationships
of face.of face.
KorkhausKorkhaus (Germany) developed a systematic diagnostic evaluation(Germany) developed a systematic diagnostic evaluation
of cephalometric films, which resembles our present analyticalof cephalometric films, which resembles our present analytical
tracing.tracing.
AfterAfter the advent of Cephalometrics in 1931 (Broadbent &the advent of Cephalometrics in 1931 (Broadbent &
Hofrath), aspects of these standardized methods were propagatedHofrath), aspects of these standardized methods were propagated
into general clinical use duringinto general clinical use during 1940-19501940-1950 [[Brodie, 1941; Downs,Brodie, 1941; Downs,
1948; Ricketts, 1950; Krogman & Sassouni, 1952; Wylie, 1952;1948; Ricketts, 1950; Krogman & Sassouni, 1952; Wylie, 1952;
Steiner, 1953; Schwartz, 1961Steiner, 1953; Schwartz, 1961]. By 1960’s it had become a]. By 1960’s it had become a
routine component of treatment planning.routine component of treatment planning.

TECHNICAL ASPECTSTECHNICAL ASPECTS
The basic components for producing a lateral cephalogram are:The basic components for producing a lateral cephalogram are:
X-ray apparatus:X-ray apparatus:
It comprises of an X-ray tube, transformers, filters, collimators, andIt comprises of an X-ray tube, transformers, filters, collimators, and
a coolant system all encased in the machines housing.a coolant system all encased in the machines housing.
Image receptor system:Image receptor system:
An image receptor system records the final product of X-rays afterAn image receptor system records the final product of X-rays after
they pass through the subject. It consists of an extra oral film,they pass through the subject. It consists of an extra oral film,
intensifying screens, cassette, grid, and a soft tissue shield.intensifying screens, cassette, grid, and a soft tissue shield.

Cephalostat:Cephalostat:
The use of aThe use of a cephalostatcephalostat, also called a, also called a head-holderhead-holder oror
cephalometercephalometer, is based on the same principle as that described by, is based on the same principle as that described by
Broadbent. The patient’s head is fixed by the two ear rods. The headBroadbent. The patient’s head is fixed by the two ear rods. The head
which is centered in the cephalostat, is oriented with the Frankfortwhich is centered in the cephalostat, is oriented with the Frankfort
plane parallel to the floor and the midsagittal plane vertical andplane parallel to the floor and the midsagittal plane vertical and
parallel to the cassetteparallel to the cassette..

CHOICE OF A HORIZONTAL REFERENCE LINECHOICE OF A HORIZONTAL REFERENCE LINE
At the International Congress of Anatomists and PhysicalAt the International Congress of Anatomists and Physical
Anthropologists held in Frankfort, Germany inAnthropologists held in Frankfort, Germany in 18821882, the, the FrankfortFrankfort
planeplane [[extending from the upper rim of the external auditory meatusextending from the upper rim of the external auditory meatus
(porion) to the inferior border of the orbital rim (orbitale)(porion) to the inferior border of the orbital rim (orbitale)], was], was
adopted as the best representation of the natural orientation of theadopted as the best representation of the natural orientation of the
skull. For living patients, however, it is possible to use a “skull. For living patients, however, it is possible to use a “truetrue
horizontalhorizontal” line, established physiologically rather than anatomically, as” line, established physiologically rather than anatomically, as
the horizontal reference plane. This approach requires that thethe horizontal reference plane. This approach requires that the
cephalometric radiographs be taken incephalometric radiographs be taken in Natural Head PositionNatural Head Position..
The inclination of SN to the true horizontal plane (or FH plane ifThe inclination of SN to the true horizontal plane (or FH plane if
THP is not known) should always be noted, and if the inclination ofTHP is not known) should always be noted, and if the inclination of
SN differs significantly fromSN differs significantly from 6 degrees6 degrees, any measurement based on, any measurement based on
SN should be correctedSN should be corrected
FH PlaneFH Plane

NHP-Natural Head Position:NHP-Natural Head Position:
BrocaBroca defined itdefined it inin 18611861 as “as “when a man is standingwhen a man is standing
and when his visual axis is horizontal, his head is in theand when his visual axis is horizontal, his head is in the
natural horizontal positionnatural horizontal position”. The simplest procedure to”. The simplest procedure to
obtain head radiographs in the NHP is to instruct theobtain head radiographs in the NHP is to instruct the
patient to sit upright and look straight ahead to a point atpatient to sit upright and look straight ahead to a point at
eye level so that the head level is determined by theeye level so that the head level is determined by the
internal physiological mechanism.internal physiological mechanism.
Other devices such as fluid level device,Other devices such as fluid level device,
inclinometer and the plumb line have been used to measureinclinometer and the plumb line have been used to measure
the head posture.the head posture.

ANALYSISANALYSIS
Cephalometric analysis is used to assess, expressCephalometric analysis is used to assess, express
and predict the spatial relations of soft tissues,and predict the spatial relations of soft tissues,
craniofacial and dentofacial complexes at one point or overcraniofacial and dentofacial complexes at one point or over
time. The analysis is eithertime. The analysis is either objectiveobjective oror subjectivesubjective..
Objective evaluationObjective evaluation involves quantification of spatialinvolves quantification of spatial
relationships by angular or linear measurements.relationships by angular or linear measurements.
Subjective evaluationSubjective evaluation involves the visualization of changesinvolves the visualization of changes
in spatial relationships of areas or anatomical landmarksin spatial relationships of areas or anatomical landmarks
within the same face and relating to a common point orwithin the same face and relating to a common point or
plane over time.plane over time.

CLASSIFICATION OF ANALYSESCLASSIFICATION OF ANALYSES
ANALYSES
Methodological Normative
Acc. To Area of
Analyses
1.1. MethodologicalMethodological::
AngularAngular:: Dimensional Analysis, Proportional Analysis, Analysis toDimensional Analysis, Proportional Analysis, Analysis to
determine position.determine position.
LinearLinear :: Orthogonal Analysis, Dimensional Linear Analysis,Orthogonal Analysis, Dimensional Linear Analysis,
Proportional Linear Analysis.Proportional Linear Analysis.

2.2. NormativeNormative::
Mononormative AnalysesMononormative Analyses:: Arithmetical or Geometrical.Arithmetical or Geometrical.
Multinormative AnalysesMultinormative Analyses..
Correlative AnalysesCorrelative Analyses..
3.3. Acc. to Area of AnalysisAcc. to Area of Analysis::
Dentoskeletal AnalysesDentoskeletal Analyses:: Facial Skeleton, Maxillary andFacial Skeleton, Maxillary and
Mandibular Base.Mandibular Base.
Dentoalveolar AnalysesDentoalveolar Analyses:: Position and Angulation of Upper &Position and Angulation of Upper &
Lower Incisors.Lower Incisors.
Soft Tissues Analyses.Soft Tissues Analyses.

APPLICATIONS IN ORTHODONTICSAPPLICATIONS IN ORTHODONTICS
Cephalometrics is used in three major areas:Cephalometrics is used in three major areas:
Morphological AnalysisMorphological Analysis; by evaluating the sagittal and; by evaluating the sagittal and
vertical relations of dentition, facial skeleton andvertical relations of dentition, facial skeleton and softsoft
tissue profile.tissue profile.
Growth AnalysisGrowth Analysis; by taking two or more cephalograms at; by taking two or more cephalograms at
different time intervals and comparing the changes.different time intervals and comparing the changes.
Treatment AnalysisTreatment Analysis; by evaluating alterations during and; by evaluating alterations during and
after therapy.after therapy.

VARIOUSVARIOUS ANALYSESANALYSES
STEINER ANALYSIS:STEINER ANALYSIS: [AJO-1960][AJO-1960] was developed and promotedwas developed and promoted
byby Cecil SteinerCecil Steiner in the 1950s. It can be considered the first of thein the 1950s. It can be considered the first of the
modern cephalometric analyses for two reasons: it displayedmodern cephalometric analyses for two reasons: it displayed
measurements in a way that emphasized not just the individualmeasurements in a way that emphasized not just the individual
measurements but their interrelationship into a pattern, and itmeasurements but their interrelationship into a pattern, and it
offered specific guides for the use of cephalometric measurements inoffered specific guides for the use of cephalometric measurements in
treatment planning.treatment planning.

SASSOUNI ANALYSISSASSOUNI ANALYSIS:: [AJO-1969][AJO-1969] was the first cephalometricwas the first cephalometric
method to emphasize vertical as well as horizontal relationships andmethod to emphasize vertical as well as horizontal relationships and
the interactions between vertical and horizontal proportions.the interactions between vertical and horizontal proportions.
Sassouni pointed out that the horizontal anatomic planes-theSassouni pointed out that the horizontal anatomic planes-the
inclination of the anterior cranial base, Frankfort plane, Palatal plane,inclination of the anterior cranial base, Frankfort plane, Palatal plane,
Occlusal plane and Mandibular plane-tend to converge toward a singleOcclusal plane and Mandibular plane-tend to converge toward a single
point in a well-proportioned face. The inclination of these planes topoint in a well-proportioned face. The inclination of these planes to
each other reflects the vertical proportionality of the face. If theeach other reflects the vertical proportionality of the face. If the
planes intersect relatively close to the face and diverge quickly asplanes intersect relatively close to the face and diverge quickly as
they pass anteriorly, the facial proportions are long anteriorly andthey pass anteriorly, the facial proportions are long anteriorly and
short posteriorly which predisposes the individual to an openbiteshort posteriorly which predisposes the individual to an openbite
malocclusion. Sassouni coined the termmalocclusion. Sassouni coined the term Skeletal Open BiteSkeletal Open Bite for thisfor this
anatomic relationship, the opposite of which isanatomic relationship, the opposite of which is Skeletal Deep BiteSkeletal Deep Bite..
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RICKETTS ANALYSIS:RICKETTS ANALYSIS: is a 11 factor summary analysis thatis a 11 factor summary analysis that
employs specific measurements toemploys specific measurements to
(1) locate the chin in space,(1) locate the chin in space,
(2) locate the maxilla trough the convexity of the face,(2) locate the maxilla trough the convexity of the face,
(3) locate the denture in the face, and(3) locate the denture in the face, and
(4) evaluate the profile. The Ricketts approach emphasizes not only an(4) evaluate the profile. The Ricketts approach emphasizes not only an
analysis of the patients initial condition, but the prediction ofanalysis of the patients initial condition, but the prediction of
future growth and treatment effects in a VTO.future growth and treatment effects in a VTO.

HARVOLD ANALYSISHARVOLD ANALYSIS,, WITS ANALYSISWITS ANALYSIS:: both analyses wereboth analyses were
aimed solely at describing the severity or degree of jaw disharmony.aimed solely at describing the severity or degree of jaw disharmony.
HarvoldHarvold [1974][1974] using data derived from the Burlington growth study,using data derived from the Burlington growth study,
developed standards for the ‘unit length’ of the maxilla and mandible.developed standards for the ‘unit length’ of the maxilla and mandible.
The difference between these provides an indication of the sizeThe difference between these provides an indication of the size
discrepancy between the jaws.discrepancy between the jaws.
TheThe Wits analysisWits analysis [AJO-1975][AJO-1975] was conceived primarily as a way towas conceived primarily as a way to
overcome the limitations of ANB as an indicator of jaw discrepancy.overcome the limitations of ANB as an indicator of jaw discrepancy.
The Wits in contrast to the Harvold analysis, is influenced by theThe Wits in contrast to the Harvold analysis, is influenced by the
teeth both horizontally and vertically.teeth both horizontally and vertically.

McNAMARA ANALYSISMcNAMARA ANALYSIS:: [AJO-1984][AJO-1984] was originally published inwas originally published in
19831983, and still represents the state of the art in cephalometric, and still represents the state of the art in cephalometric
measurement analysis reasonably well. It combines elements ofmeasurement analysis reasonably well. It combines elements of
previous approaches (Ricketts and Harvold) with originalprevious approaches (Ricketts and Harvold) with original
measurements to attempt a more precise definition of tooth and jawmeasurements to attempt a more precise definition of tooth and jaw
positions.positions.
This analysis has two major strengths: (1) it relates the jaws via theThis analysis has two major strengths: (1) it relates the jaws via the
nasion perpendicular, in essence projecting the difference innasion perpendicular, in essence projecting the difference in
anteroposterior position of the jaws to an approximation of the trueanteroposterior position of the jaws to an approximation of the true
vertical line, (2) the normative data are based on well defined Boltonvertical line, (2) the normative data are based on well defined Bolton
sample, which is also available in template form, meaning that thesample, which is also available in template form, meaning that the
McNamara measurements are highly compatible with preliminaryMcNamara measurements are highly compatible with preliminary
analysis by comparison with Bolton templates.analysis by comparison with Bolton templates.

ENLOWS COUNTERPART ANALYSISENLOWS COUNTERPART ANALYSIS:: [AJO-1969][AJO-1969] The basicThe basic
idea of interrelated dimensions leading to an ultimately balanced oridea of interrelated dimensions leading to an ultimately balanced or
unbalanced facial pattern was expressed well by Enlow in theunbalanced facial pattern was expressed well by Enlow in the 1960s1960s, in, in
his “counterpart analysis”. As Enlow et al pointed out, both thehis “counterpart analysis”. As Enlow et al pointed out, both the
dimensions and alignment of craniofacial components are important indimensions and alignment of craniofacial components are important in
determining the overall facial balance.determining the overall facial balance.
TWEED ANALYSISTWEED ANALYSIS:: [AO-1954][AO-1954] originally included only threeoriginally included only three
measurements. It is centered around two highly critical parameters:measurements. It is centered around two highly critical parameters:
the position of the mandibular incisors (over the basal bone), and thethe position of the mandibular incisors (over the basal bone), and the
angle FMA, which represents the (anterior) vertical dimension of theangle FMA, which represents the (anterior) vertical dimension of the
maxilla and the mandible.maxilla and the mandible. www.indiandentalacademy.com

DOWNS’ ANALYSISDOWNS’ ANALYSIS:: [AO-1956][AO-1956] when observing facial profiles,when observing facial profiles,
W B Downs noted that generally the position of the mandible could beW B Downs noted that generally the position of the mandible could be
used in determining whether or not faces were balanced. Downsused in determining whether or not faces were balanced. Downs
reduced his observations to the following four basic facial types:reduced his observations to the following four basic facial types:
Retrognathic, Mesognathic, Prognathic andRetrognathic, Mesognathic, Prognathic and
True PrognathismTrue Prognathism (a pronounced protrusion of the lower face)(a pronounced protrusion of the lower face)

WYLIE ANALYSISWYLIE ANALYSIS:: [AO-1947][AO-1947] The terms “The terms “orthognathismorthognathism” and” and
““prognathismprognathism” were selected to categorize facial types, in preference” were selected to categorize facial types, in preference
to “Class II faces” and “Class III faces”.to “Class II faces” and “Class III faces”.
““Prognathism” and “orthognathism”, when used by others, may applyPrognathism” and “orthognathism”, when used by others, may apply
either to the maxilla or the mandible or both. As it is used here iteither to the maxilla or the mandible or both. As it is used here it
applies mainly to the mandible in relation to the maxilla. A method isapplies mainly to the mandible in relation to the maxilla. A method is
presented whereby discrepancies in size of facial bones occurring inpresented whereby discrepancies in size of facial bones occurring in
the anteroposterior plane of space may be assessed quantitatively inthe anteroposterior plane of space may be assessed quantitatively in
terms of millimeters. The method of assessment presented makesterms of millimeters. The method of assessment presented makes
possible a net score of anteroposterior dysplasia which ispossible a net score of anteroposterior dysplasia which is
approximatelyapproximately zerozero where such dysplasia is either non-existent orwhere such dysplasia is either non-existent or
compensated for by variation in different parts, and which is negativecompensated for by variation in different parts, and which is negative
in the type of face where relative mandibular insufficiency exists, andin the type of face where relative mandibular insufficiency exists, and
positive in cases of mandibular prognathism.positive in cases of mandibular prognathism.

BJORKS ANALYSISBJORKS ANALYSIS:: [1954][1954] the mechanism for thethe mechanism for the
control and modification of craniofacial growth had beencontrol and modification of craniofacial growth had been
discussed earlier by Bjork, who noted after a survey ofdiscussed earlier by Bjork, who noted after a survey of
cephalometric X-ray analyses that compensation wascephalometric X-ray analyses that compensation was
dominant during adolescence, while dysplastic changesdominant during adolescence, while dysplastic changes
appeared mainly at an early stage of development.appeared mainly at an early stage of development.

DI PAOLO’S QUADRILATERAL ANALYSISDI PAOLO’S QUADRILATERAL ANALYSIS:: [AJO-1983][AJO-1983] TheThe
quadrilateral analysis offers an individualized cephalometric diagnosis onquadrilateral analysis offers an individualized cephalometric diagnosis on
patients with or without skeletal dysplasias. It includespatients with or without skeletal dysplasias. It includes SkeletalSkeletal
assessment, Dental assessment and Assessment of Facial Typesassessment, Dental assessment and Assessment of Facial Types
(normodivergent, hypodivergent and hyperdivergent)(normodivergent, hypodivergent and hyperdivergent). It is a reliable and. It is a reliable and
accurate method of assessing whether orthodontic treatment, surgicalaccurate method of assessing whether orthodontic treatment, surgical
treatment, or a combination of both is required to achieve atreatment, or a combination of both is required to achieve a
satisfactory result.satisfactory result.
RIEDEL ANALYSISRIEDEL ANALYSIS:: [AO-1952][AO-1952] was established on the basis of awas established on the basis of a
study undertaken by Richard A Riedel to determine the constancy orstudy undertaken by Richard A Riedel to determine the constancy or
variation in the relation of maxilla to cranium and the mandible.variation in the relation of maxilla to cranium and the mandible.

Other Analyses are:Other Analyses are:
SCHWARZ ANALYSISSCHWARZ ANALYSIS: [AJO-1961]: [AJO-1961]
JARABAK ANALYSISJARABAK ANALYSIS:[1972]:[1972]
WORMS AND COWORKERS ANALYSISWORMS AND COWORKERS ANALYSIS: [AO-1976]: [AO-1976]
HASUND ANALYSISHASUND ANALYSIS: [1977]: [1977]
FARKAS AN COWORKERS ANALYSISFARKAS AN COWORKERS ANALYSIS: [1985]: [1985]
COBEN CRANIOFACIAL AND DENTITIONCOBEN CRANIOFACIAL AND DENTITION
ANALYSESANALYSES: [1986]: [1986]

SOFT TISSUE CEPHALOMETRIC ANALYSISSOFT TISSUE CEPHALOMETRIC ANALYSIS
A good mechanical relationship between maxillary andA good mechanical relationship between maxillary and
mandibular dentures was formerly regarded as the sole aim ofmandibular dentures was formerly regarded as the sole aim of
orthodontic treatment. In the course of time, however, orthodontistsorthodontic treatment. In the course of time, however, orthodontists
have become increasingly aware that facia esthetics must also behave become increasingly aware that facia esthetics must also be
considered in planning. According toconsidered in planning. According to WuerpelWuerpel, a face is beautiful and, a face is beautiful and
shows harmonious featuresif the proportions of its individualshows harmonious featuresif the proportions of its individual
components are right, ie, no individual structure is over emphasized incomponents are right, ie, no individual structure is over emphasized in
relation to the others - what he refers to as ‘balance’.relation to the others - what he refers to as ‘balance’.
For soft tissue analysis, distinction is made between:For soft tissue analysis, distinction is made between:
Profile Analysis.Profile Analysis.
Lip Analysis.Lip Analysis.
Tongue Analysis.Tongue Analysis.

PROFILE ANALYSIS:PROFILE ANALYSIS:
Further divided intoFurther divided into Proportional AnalysisProportional Analysis andand Angular Profile Analysis.Angular Profile Analysis.
Proportional AnalysisProportional Analysis:: were in the profile may be divided into three approximatelywere in the profile may be divided into three approximately
equal parts,equal parts, Frontal Third (tr-n),Frontal Third (tr-n),
Nasal Third (n-sn), andNasal Third (n-sn), and
Gnathic Third (sn-gn).Gnathic Third (sn-gn).
Angular Profile AnalysisAngular Profile Analysis:: were inwere in SubtelnySubtelny makes the distinction between themakes the distinction between the
convexity of,convexity of, the skeletal profile,the skeletal profile,
the soft tissue profile, andthe soft tissue profile, and
the full soft tissue profile (including thethe full soft tissue profile (including the
nose).nose).
Skeletal Convexity is represented by N-A-Pog mean=175°Skeletal Convexity is represented by N-A-Pog mean=175°
Soft Tissue convexity is determined as n-sn-pog mean=161°Soft Tissue convexity is determined as n-sn-pog mean=161°
Full Soft Tissue Convexity is based on n-n-pog mean=137°M/133°FFull Soft Tissue Convexity is based on n-n-pog mean=137°M/133°F

Profile Analysis by A M Schwarz:Profile Analysis by A M Schwarz: were in three reference lines arewere in three reference lines are
constructed for profile analysis:constructed for profile analysis:
1. The H line, corresponding to the FH plane,1. The H line, corresponding to the FH plane,
2. The Pn line, and2. The Pn line, and
3. The Po line (orbital perpendicular), a perpendicular from the orbital3. The Po line (orbital perpendicular), a perpendicular from the orbital
toto the H line.the H line.
TheThe Gnathic Profile Field (GPF)Gnathic Profile Field (GPF) permits assessment of the profile.permits assessment of the profile.
Depending on the position of the subnasale relative to the nasion perpendicularDepending on the position of the subnasale relative to the nasion perpendicular
three types of faces are seen,three types of faces are seen,
1.1. Average FaceAverage Face – sn on nasion perpendicular,– sn on nasion perpendicular,
2.2. RetrofaceRetroface – sn behind the nasion perpendicular, and– sn behind the nasion perpendicular, and
3.3. AntefaceAnteface – sn in front of the nasion perpendicular.– sn in front of the nasion perpendicular.

LIP ANALYSIS:LIP ANALYSIS:
Analysis of the lip plays a significant role in treatment planning.Analysis of the lip plays a significant role in treatment planning.
Ricketts:Ricketts: uses the E line drawn from the tip of the nose to skin pogonion.uses the E line drawn from the tip of the nose to skin pogonion.
Steiners:Steiners: uses the S line drawn from the centre of the S shaped curveuses the S line drawn from the centre of the S shaped curve
between the tip of the nose and sn, to the pog.between the tip of the nose and sn, to the pog.
Holdaways Lip Analysis:Holdaways Lip Analysis: this is a quantitative analysis to assess lipthis is a quantitative analysis to assess lip
configuration.configuration. Holdaway determines the angle between a tangentHoldaway determines the angle between a tangent to theto the
upper lip and NB line, called the H angle.upper lip and NB line, called the H angle.
Holdaway defines the perfect profile as follows:Holdaway defines the perfect profile as follows:
-ANB angle 2°, H angle 7-8°.-ANB angle 2°, H angle 7-8°.
-Lower lip touching the soft tissue line, and with-Lower lip touching the soft tissue line, and with
-The relative proportions of nose and upper lip well balanced.-The relative proportions of nose and upper lip well balanced.

TONGUE ANALYSIS:TONGUE ANALYSIS:
Contains two parametersContains two parameters
1) assessing tongue position, and1) assessing tongue position, and
2) assessing tongue motility2) assessing tongue motility
Tongue PositionTongue Position: in relation to the: in relation to the
RootRoot:: a space is formed between the root of the tongue and soft palatea space is formed between the root of the tongue and soft palate
in cases of mouth breathing (nasal obstruction) & Cl IIin cases of mouth breathing (nasal obstruction) & Cl II
malocclusion.malocclusion.
DorsumDorsum:: of the tongue is high in Cl II malocclusion and in deepbite cases.of the tongue is high in Cl II malocclusion and in deepbite cases.
In all others it is low.In all others it is low.
TipTip: is retracted in Cl III and in Cl II with nasal breathing and in: is retracted in Cl III and in Cl II with nasal breathing and in
deepbite cases. In openbite, tip is forwarddeepbite cases. In openbite, tip is forward..

Tongue MotilityTongue Motility:: the changes in the position of the tip relate closely tothe changes in the position of the tip relate closely to
the different types of malocclusion.the different types of malocclusion.
With Cl II the tip is back at rest position, and with Cl III theWith Cl II the tip is back at rest position, and with Cl III the
tip lies further forward. It may be assumed that the changes in positiontip lies further forward. It may be assumed that the changes in position
of the tip of the tongue relate to the tendency to mandibularof the tip of the tongue relate to the tendency to mandibular
malformation.malformation.

ARNETT & BERGMAN ANALYSIS:ARNETT & BERGMAN ANALYSIS:
The analysis is a radiographic instrument that was developedThe analysis is a radiographic instrument that was developed
directly from the philosophy expressed in Arnett and Bergman’sdirectly from the philosophy expressed in Arnett and Bergman’s FacialFacial
keys to orthodontic diagnosis and treatment planningkeys to orthodontic diagnosis and treatment planning [AJO April /[AJO April /
May 1993]May 1993].. Many authors have suggested utilizing soft tissueMany authors have suggested utilizing soft tissue
analysis as a reliable guide for occlusal treatment and attendant softanalysis as a reliable guide for occlusal treatment and attendant soft
tissue changes. Arnett and Bergman presented the Facial Keys totissue changes. Arnett and Bergman presented the Facial Keys to
Orthodontic Diagnosis and Treatment Planning as a three-dimensionalOrthodontic Diagnosis and Treatment Planning as a three-dimensional
clinical blueprint for soft tissue analysis and treatment planning.clinical blueprint for soft tissue analysis and treatment planning.
In preparation for the cephalometric radiograph, metallicIn preparation for the cephalometric radiograph, metallic
markers were placed on the right side of the face to mark keymarkers were placed on the right side of the face to mark key
midface structures. These included the orbital rim marker,midface structures. These included the orbital rim marker,
cheekbone marker, alar base marker, subpupil marker and neck-throatcheekbone marker, alar base marker, subpupil marker and neck-throat
marker. Themarker. The True Vertical LineTrue Vertical Line (TVL) was then established. The line(TVL) was then established. The line
was placed through subnasale and was perpendicular to the naturalwas placed through subnasale and was perpendicular to the natural
horizontal head position.horizontal head position.
...........contd............contd.www.indiandentalacademy.com

CLINICAL IMPLICATIONS:CLINICAL IMPLICATIONS:
Soft Tissue CephalometricSoft Tissue Cephalometric
Analysis (STCA)Analysis (STCA) provides dentalprovides dental
and facial diagnosis. Data providedand facial diagnosis. Data provided
by the STCA can then be used forby the STCA can then be used for
Cephalometric Treatment PlanningCephalometric Treatment Planning
(CTP).(CTP). The STCA can be used toThe STCA can be used to
diagnose the patient in fivediagnose the patient in five
different but interrelated areasdifferent but interrelated areas;;
dentoskeletal factors, soft tissuedentoskeletal factors, soft tissue
components, facial lengths, TVLcomponents, facial lengths, TVL
projections, and harmony of partsprojections, and harmony of parts..
................contd.................contd.www.indiandentalacademy.com

CEPHALOMETRIC TREATMENT PLANNING (CTP):CEPHALOMETRIC TREATMENT PLANNING (CTP):
Diagnosis generated by STCA is used to guide cephalometricDiagnosis generated by STCA is used to guide cephalometric
treatment planning. Seven steps are involved in CTP to optimizetreatment planning. Seven steps are involved in CTP to optimize
occlusal and facial results:occlusal and facial results:
1.1. Proper angulation of lower incisor teeth,Proper angulation of lower incisor teeth,
2.2. Proper angulation of upper incisors,Proper angulation of upper incisors,
3.3. Maxillary incisor positioning,Maxillary incisor positioning,
4.4. Autorotation of mandible to 3mm of overbite,Autorotation of mandible to 3mm of overbite,
5.5. Mandible is moved anteriorly or posteriorly to correct the overjetMandible is moved anteriorly or posteriorly to correct the overjet
with the maxillary arch,with the maxillary arch,
6.6. Maxillary occlusal plane is defined, and lastlyMaxillary occlusal plane is defined, and lastly
7.7. Chin projection and height assessmentChin projection and height assessment..
...........contd............contd.www.indiandentalacademy.com

Cephalometric Treatment Planning:Cephalometric Treatment Planning:
There are a number of other soft tissue analysis such asThere are a number of other soft tissue analysis such as Powell’sPowell’s,, Farka’sFarka’s,, Lehman’sLehman’s,,
BBurstone’surstone’s,, Wolford’sWolford’s,, Bolton’sBolton’s,, Spradley’sSpradley’s,, BowkerBowker andand Meredith’sMeredith’s andand Holdaway’sHoldaway’s
soft tissue analysissoft tissue analysis. The. The Reed Holdaway’s analysisReed Holdaway’s analysis has 11 measurements includinghas 11 measurements including
facial angle, upperlip curvature, skeletal convexity, upper and lower depth,facial angle, upperlip curvature, skeletal convexity, upper and lower depth,
thickness and strain, harmony line angle etc.thickness and strain, harmony line angle etc.

FUNCTIONAL ANALYSIS OF THE RADIOGRAPHFUNCTIONAL ANALYSIS OF THE RADIOGRAPH
Cephalometric radiography will also demonstrate theCephalometric radiography will also demonstrate the
relationship between rest and occlusal positionsrelationship between rest and occlusal positions. Relative to. Relative to
its occlusal position, the mandible may be further back orits occlusal position, the mandible may be further back or
further forward than in rest position. If a radiograph isfurther forward than in rest position. If a radiograph is
taken in rest position and another in occlusion, mutualtaken in rest position and another in occlusion, mutual
relations between these two may be established. In everyrelations between these two may be established. In every
movement of the mandible we can differentiate between amovement of the mandible we can differentiate between a
rotatory and gliding component. The principle ofrotatory and gliding component. The principle of
comparative assessment consists in the determination ofcomparative assessment consists in the determination of
one angle for the rotational component and another for theone angle for the rotational component and another for the
gliding component.gliding component.

ASSESSING HORIZONTAL RELATIONSASSESSING HORIZONTAL RELATIONS --
ORTHO/RETRO/PROGNATHICORTHO/RETRO/PROGNATHIC::
Cephalometrics helps in finding out whether theCephalometrics helps in finding out whether the
fault is in the maxilla or mandible in the cases of Cl II orfault is in the maxilla or mandible in the cases of Cl II or
Cl III. Also in the maxilla whether the malocclusion is dueCl III. Also in the maxilla whether the malocclusion is due
to fault in the basal bone or dento-alveolar or purelyto fault in the basal bone or dento-alveolar or purely
dental proclination. The treatment for each differs, fromdental proclination. The treatment for each differs, from
a bodily movement required in the basal bone fault, to justa bodily movement required in the basal bone fault, to just
an incisor tipping in case of pure dental proclination. Foran incisor tipping in case of pure dental proclination. For
assessing this the angles SNA, SNB, upper incisorassessing this the angles SNA, SNB, upper incisor
angulation and position relative to N-Pog line areangulation and position relative to N-Pog line are
important.important.

ASSESSING VERTICAL RELATIONSASSESSING VERTICAL RELATIONS::
If growth in the posterior face (condylar growth) is greaterIf growth in the posterior face (condylar growth) is greater
than that in the anterior face (growth in facial sutures and alveolarthan that in the anterior face (growth in facial sutures and alveolar
growth), it causes forward rotation; while growth of anterior facegrowth), it causes forward rotation; while growth of anterior face
greater than posterior face causes backward rotation. Equal growthgreater than posterior face causes backward rotation. Equal growth
produces no rotation but only parallel displacement.produces no rotation but only parallel displacement.
Mandibular rotation not only produces retro/prognathism butMandibular rotation not only produces retro/prognathism but
also deep/open bite. Therefore by determining this rotation, it isalso deep/open bite. Therefore by determining this rotation, it is
helpful in treatment planning. With forward rotation, treatment of Clhelpful in treatment planning. With forward rotation, treatment of Cl
III and deep bite are difficult. With backward rotation, treatmentIII and deep bite are difficult. With backward rotation, treatment
of Cl II and openbite are difficult.of Cl II and openbite are difficult.
Maxillary rotation occurs in midface which is partly due toMaxillary rotation occurs in midface which is partly due to
growth and rest due to occlusal forces and gravity. Rotation alsogrowth and rest due to occlusal forces and gravity. Rotation also
develops during headgear therapy and specially developed activators.develops during headgear therapy and specially developed activators.
Therapeutic parallel displacements of the maxilla enforced byTherapeutic parallel displacements of the maxilla enforced by
translation are less liable to relapse.translation are less liable to relapse.
Measuring the centre of such rotation is possible byMeasuring the centre of such rotation is possible by
superimposing cephalometric radiographs taken before and aftersuperimposing cephalometric radiographs taken before and after
treatment.treatment. www.indiandentalacademy.com

AIMS OF INTERPRETATION OF THEAIMS OF INTERPRETATION OF THE
MEASUREMENTSMEASUREMENTS
 To determine the skeletal structure and facial type.To determine the skeletal structure and facial type.
 To establish relationship between max. and man. base andTo establish relationship between max. and man. base and
determine type of growth.determine type of growth.
 To assess dental relationships.To assess dental relationships.
 To analyse the soft tissues regarding aetiology and prognosis.To analyse the soft tissues regarding aetiology and prognosis.
 To establish location of malocclusion and in the facial skull andTo establish location of malocclusion and in the facial skull and
determine, the extent to which it is skeletal /determine, the extent to which it is skeletal /
dentoalveolar.dentoalveolar.
 Treatment planning, and also to determine how far, theTreatment planning, and also to determine how far, the
treatment can be causal and how far merely compensatorytreatment can be causal and how far merely compensatory
(for skeletal abnormalities).(for skeletal abnormalities).

GROWTH PREDICTIONGROWTH PREDICTION
The site, direction, growth potential, growth timing andThe site, direction, growth potential, growth timing and
growth pattern have to be determined. Generallygrowth pattern have to be determined. Generally
horizontal growth changes are easily predictable thanhorizontal growth changes are easily predictable than
vertical changes.vertical changes.
 Forecast Grid:Forecast Grid: L E JohnstonL E Johnston has produced a diagram onhas produced a diagram on
the assumption of regular annual changes and an averagethe assumption of regular annual changes and an average
direction of growth. He feels accurate prediction can bedirection of growth. He feels accurate prediction can be
made in 65% of the cases. In this forecast grid eachmade in 65% of the cases. In this forecast grid each
point was advanced one grid per year.point was advanced one grid per year.

 Rickett's short term predictionRickett's short term prediction makes distinction betweenmakes distinction between
vertical and horizontal growth.vertical and horizontal growth. Rickett's Computer AnalysisRickett's Computer Analysis
considers individual growth curves for separate regions. Theconsiders individual growth curves for separate regions. The
computer diagnosis requires the patient to be of a certain age.computer diagnosis requires the patient to be of a certain age.
During growth noticeable increase in linear dimensions of N-Me,During growth noticeable increase in linear dimensions of N-Me,
S-Gn, Ar-Gn occurs. There is an average increase in SN line. ThisS-Gn, Ar-Gn occurs. There is an average increase in SN line. This
is used for prediction of sagittal and vertical growth changes.is used for prediction of sagittal and vertical growth changes.
Growth rate of different regional growth centres is different.Growth rate of different regional growth centres is different.
Also age and function change the form of growth. In order toAlso age and function change the form of growth. In order to
determine the stability of the results and length of retentiondetermine the stability of the results and length of retention
period, growth following conclusion of treatment is determinedperiod, growth following conclusion of treatment is determined..
 Holdaway's Growth prediction:Holdaway's Growth prediction: itit is based on the average increaseis based on the average increase
in SN line. We can assess the different possibilities of treatment,in SN line. We can assess the different possibilities of treatment,
thus visualize certain treatment objectives. It has some 12 stagesthus visualize certain treatment objectives. It has some 12 stages
of superimposition and was found that horizontal growth wasof superimposition and was found that horizontal growth was
better predictable.better predictable.

SUPERIMPOSITIONSUPERIMPOSITION
Serial superimposition of cephalograms reveals theSerial superimposition of cephalograms reveals the
rate, amount and relative directions of the growth andrate, amount and relative directions of the growth and
treatment changes of facial structures, including thetreatment changes of facial structures, including the
changes in maxillary mandibular relationships, and thechanges in maxillary mandibular relationships, and the
relative changes in the soft tissue integument. It howeverrelative changes in the soft tissue integument. It however
does notdoes not reveal either the sites or mode of growth ofreveal either the sites or mode of growth of
bone. 2D information was interpreted of a 3D process. Itbone. 2D information was interpreted of a 3D process. It
demonstrates the sum total of apposition and resorptiondemonstrates the sum total of apposition and resorption
at that particular time without detailed interveningat that particular time without detailed intervening
changes.changes.

Maxillary Superimposition:Maxillary Superimposition:
A comparison of three methods for cephalometric evaluation ofA comparison of three methods for cephalometric evaluation of
growth and treatment change was made bygrowth and treatment change was made by Neilson [AJO 1989 May].Neilson [AJO 1989 May].
Previous cephalometric studies have indicated an apparent stability ofPrevious cephalometric studies have indicated an apparent stability of
the growth patterns of both the maxilla and mandible. There is athe growth patterns of both the maxilla and mandible. There is a
parallel descent of the maxilla, in relation to the anterior cranial base,parallel descent of the maxilla, in relation to the anterior cranial base,
in which the nasal floor appeared to remain unchanged during growth.in which the nasal floor appeared to remain unchanged during growth.
The technique most commonly used for evaluating growth andThe technique most commonly used for evaluating growth and
treatment changes has been to superimpose serial head films alongtreatment changes has been to superimpose serial head films along
the palatal plane from ANS to PNS with the films registered at ANS.the palatal plane from ANS to PNS with the films registered at ANS.
BroadbentBroadbent found that when superimposition was made on the palatalfound that when superimposition was made on the palatal
plane at ANS, the anterior surface of the maxilla and point A movedplane at ANS, the anterior surface of the maxilla and point A moved
posteriorly.posteriorly. Brodie and DownsBrodie and Downs recommended the superimposition ofrecommended the superimposition of
the nasal floors and films registered at the anterior surface of thethe nasal floors and films registered at the anterior surface of the
maxilla.maxilla.

The superior and inferior surfaces of the hard palate have beenThe superior and inferior surfaces of the hard palate have been
recommended for maxillary superimposition to eliminate possiblerecommended for maxillary superimposition to eliminate possible
appositional growth at ANS.appositional growth at ANS. MooreMoore suggested the superimpositionsuggested the superimposition
along the palatal plane but registered at the pterygomaxillary fissure.along the palatal plane but registered at the pterygomaxillary fissure.
RiedelRiedel coincided the infratemporal fossa and the posterior portion ofcoincided the infratemporal fossa and the posterior portion of
the hard palate.the hard palate. LuderLuder made superimposition on the anterior contour ofmade superimposition on the anterior contour of
the zygomatic process registered at the most inferior point of thethe zygomatic process registered at the most inferior point of the
process at key ridge.process at key ridge.
Studies of maxillary growth with metallic implants byStudies of maxillary growth with metallic implants by Bjork andBjork and
SkiellerSkieller have demonstrated that the maxilla undergoes extensivehave demonstrated that the maxilla undergoes extensive
differential remodeling- a resorptive lowering of the nasal floor,differential remodeling- a resorptive lowering of the nasal floor,
greater anteriorly than posteriorly. It showed that the zygomaticgreater anteriorly than posteriorly. It showed that the zygomatic
process of the maxilla does not undergo the same remodeling changes.process of the maxilla does not undergo the same remodeling changes.
In fact the anterior surface remains unchanged during growth with theIn fact the anterior surface remains unchanged during growth with the
exception of the most inferior part at key ridge and the most superiorexception of the most inferior part at key ridge and the most superior
part at the orbital floor. There is appositional growth at the orbitalpart at the orbital floor. There is appositional growth at the orbital
foor.foor.

On the basis of these findings,On the basis of these findings, Bjork and SkiellerBjork and Skieller
have suggested a “structural method” for evaluatinghave suggested a “structural method” for evaluating
maxillary growth and treatment changes. The head filmsmaxillary growth and treatment changes. The head films
are superimposed on the anterior surface of theare superimposed on the anterior surface of the
zygomatic processof the maxilla with the second head filmzygomatic processof the maxilla with the second head film
oriented so that the resorptive lowering of the nasal floororiented so that the resorptive lowering of the nasal floor
is equal to the apposition at the orbital floor. In generalis equal to the apposition at the orbital floor. In general
the results of the comparitive study between thethe results of the comparitive study between the
different methods of superimposition showed that thedifferent methods of superimposition showed that the
displacement of the dental landmarks was greater withdisplacement of the dental landmarks was greater with
the implant superimposition than with best fit.the implant superimposition than with best fit.
Comparison between the implant and the structuralComparison between the implant and the structural
methods, showed no significant difference in the verticalmethods, showed no significant difference in the vertical
plane. In the horizontal plane, overall less displacementplane. In the horizontal plane, overall less displacement
was observed with the structural method.was observed with the structural method.

Mandibular superimposition:Mandibular superimposition:
In the workshop on cephalometry conducted inIn the workshop on cephalometry conducted in 19601960 superimpositionsuperimposition
of radiographs along the lower border of the mandible was adopted.of radiographs along the lower border of the mandible was adopted.
Superimposition of the inferior border, however, proved difficultSuperimposition of the inferior border, however, proved difficult
because of the curving path of the radiographic outline; to overcomebecause of the curving path of the radiographic outline; to overcome
this problem,this problem, DownsDowns suggested a single straight line from the lowestsuggested a single straight line from the lowest
point on the external contour of the symphysis to the midpoint at thepoint on the external contour of the symphysis to the midpoint at the
gonian angle.gonian angle.
Bjork’sBjork’s studies have shown, however, that the inferior border of thestudies have shown, however, that the inferior border of the
mandible undergoes extensive differential remodeling during growth.mandible undergoes extensive differential remodeling during growth.
The anterosuperior border of the chin, inner cortical structure of theThe anterosuperior border of the chin, inner cortical structure of the
inferior border of the symphysis, lower contour of the developinginferior border of the symphysis, lower contour of the developing
molar tooth germ and mandibular canal could be used to analyzemolar tooth germ and mandibular canal could be used to analyze
mandibular growth. This wasmandibular growth. This was Bjork'sBjork's structural method ofstructural method of
superimposition.superimposition.
RickettsRicketts developed a four-position analysis to study growth anddeveloped a four-position analysis to study growth and
treatment changes in the craniofacial complex. Position four uses thetreatment changes in the craniofacial complex. Position four uses the
reference line, the corpus axis, which is used for analysis ofreference line, the corpus axis, which is used for analysis of
mandibular changes.mandibular changes.

 Cranial Base superimposition:Cranial Base superimposition:
1)1) Superimposition on the best fit of anterior cranial base anatomy:Superimposition on the best fit of anterior cranial base anatomy:
Based onBased on de Coster'sde Coster's observation of a stable basocranial lineobservation of a stable basocranial line
from inner contour of frontal bone to the anterior aspect of sellafrom inner contour of frontal bone to the anterior aspect of sella
turcicaturcica BjorkBjork advocated superimposing the anterior wall of sellaadvocated superimposing the anterior wall of sella
turcica, the anterior contours of middle cranial fossa, the contoursturcica, the anterior contours of middle cranial fossa, the contours
of cribriform plate and fronto ethmoidal crests and cerebralof cribriform plate and fronto ethmoidal crests and cerebral
surfaces of the orbital roof and cortical layers of the frontal bone.surfaces of the orbital roof and cortical layers of the frontal bone.
The cribriform plate stops growing in length antero posteriorlyThe cribriform plate stops growing in length antero posteriorly
after 2 yrs of age.after 2 yrs of age.

2)2) Superimposition on sella nasionSuperimposition on sella nasion::
It is found to be relatively stable.It is found to be relatively stable. SteinerSteiner used SN plane withused SN plane with
registration at S to evaluate mandibular positions. And registrationregistration at S to evaluate mandibular positions. And registration
at N to evaluate position of maxilla (SNA changes).at N to evaluate position of maxilla (SNA changes). BjorkBjork used sella asused sella as
the registration point to assess changes in both jaws. It is especiallythe registration point to assess changes in both jaws. It is especially
suitable during adoloscence because of constancy in relation SN andsuitable during adoloscence because of constancy in relation SN and
the deepest median contour of the anterior cranial fossa. But SNthe deepest median contour of the anterior cranial fossa. But SN
plane can't be used for facial contour estimation because ofplane can't be used for facial contour estimation because of
displacement of Nasion with growth of fronto nasal suture.displacement of Nasion with growth of fronto nasal suture. StramrudStramrud
used sella ethmoidale (SE) because of variations of nasion SE and SNused sella ethmoidale (SE) because of variations of nasion SE and SN
plane vary little after 3 yrs of age.plane vary little after 3 yrs of age. Rickett'sRickett's used the FHplane.used the FHplane.
3)3) Superimposition at registration point R with Bolton-Nasion planesSuperimposition at registration point R with Bolton-Nasion planes
parallel:parallel:
This method was introducedbyThis method was introducedby BroadbentBroadbent. A perpendicular to. A perpendicular to
sella fromsella from
Bo- N plane is erected. The mid point of this line is registration pointBo- N plane is erected. The mid point of this line is registration point
R. Superimposition is done with registration at R keeping Bo- N planeR. Superimposition is done with registration at R keeping Bo- N plane
parallel over each film.parallel over each film.

4)4) Superimposition over basion nasion plane:Superimposition over basion nasion plane:
Advocated byAdvocated by RickettsRicketts. A point called pterygoid point is. A point called pterygoid point is
selected at the lower rim of foramen rotundurn as the highest andselected at the lower rim of foramen rotundurn as the highest and
most posterior point of the pterygopalatine fossa. A line from Pt tomost posterior point of the pterygopalatine fossa. A line from Pt to
Gnathion constitutes the central axis.Gnathion constitutes the central axis.
Atr, the inter section of Ba- N and central axis is located at a pointAtr, the inter section of Ba- N and central axis is located at a point
CC which is used as a reference centre. The angle between Ba-N andCC which is used as a reference centre. The angle between Ba-N and
central axis indicates the position of the mandible relative to cranialcentral axis indicates the position of the mandible relative to cranial
base. The direction of mandibular growth is evaluated by changes inbase. The direction of mandibular growth is evaluated by changes in
the direction of the central axis. Registration at nasion depictsthe direction of the central axis. Registration at nasion depicts
changes in position of maxilla through movement of Pt.changes in position of maxilla through movement of Pt.
The best fit method of anterior cranial base is better than othersThe best fit method of anterior cranial base is better than others
because it takes into consideration the detailed individual anatomy ofbecause it takes into consideration the detailed individual anatomy of
the cranial base, rather than simplifying this anatomy into lines andthe cranial base, rather than simplifying this anatomy into lines and
points.points.

FINITE ELEMENT ANALYSISFINITE ELEMENT ANALYSIS
It was first used to analyse cephalograms byIt was first used to analyse cephalograms by Moss et alMoss et al andand
BooksteinBookstein et alet al inin 19851985. It is an engineering principle that uses partial. It is an engineering principle that uses partial
differential equations to interpolate loading values for intermediatedifferential equations to interpolate loading values for intermediate
points inpoints in irregularirregular structures by dividing the structure into sets ofstructures by dividing the structure into sets of
regularregular geometric shapes (usually into a triangle).geometric shapes (usually into a triangle).
A finite element is a small block that is a part of the whole objectA finite element is a small block that is a part of the whole object
under consideration. For example if you consider mandible, as a whole it isunder consideration. For example if you consider mandible, as a whole it is
difficult to predict the growth pattern of the mandible. However shoulddifficult to predict the growth pattern of the mandible. However should
the mandible be visualised as "broken into small regular geometricthe mandible be visualised as "broken into small regular geometric
shapes" like a triangle the problem of mandibular growth has now brokenshapes" like a triangle the problem of mandibular growth has now broken
into the problem of growth of the individual triangles. The exact growthinto the problem of growth of the individual triangles. The exact growth
can now be reproduced by reassembling the individual blocks.can now be reproduced by reassembling the individual blocks.
Recent advances in finite element allow irregular patterns forRecent advances in finite element allow irregular patterns for
objects that are evenobjects that are even non-homogeneousnon-homogeneous to be assessed (earlier onlyto be assessed (earlier only
homogeneous materials were assessed by this method), and this allowshomogeneous materials were assessed by this method), and this allows
for accurate reproduction of mandibular growth.for accurate reproduction of mandibular growth.

DISTINGUISHING BETWEEN NATURAL GROWTHDISTINGUISHING BETWEEN NATURAL GROWTH
FROM ORTHODONTIC CHANGESFROM ORTHODONTIC CHANGES
A Four-Step method to distinguish orthodontic changes fromA Four-Step method to distinguish orthodontic changes from
natural growth:natural growth: (ROBERT MURRAY RICKETTS)(ROBERT MURRAY RICKETTS) [JCO 1975][JCO 1975]
RickettsRicketts suggested a method of superimposition to accomplish this.suggested a method of superimposition to accomplish this.
Method of Superpositioning:Method of Superpositioning:
The objective of the four position analysis is very simple- two skeletalThe objective of the four position analysis is very simple- two skeletal
and two dental. First, it attempts to analyze the skeleton in terms ofand two dental. First, it attempts to analyze the skeleton in terms of
the chin, and secondly the maxilla. This comes from Position One andthe chin, and secondly the maxilla. This comes from Position One and
Position Two, respectively. Position Three is for the maxillary teeth.Position Two, respectively. Position Three is for the maxillary teeth.
Position Four is for the mandibular teeth.Position Four is for the mandibular teeth.

Pitchfork Analysis:Pitchfork Analysis:
To evaluate growth and displacement of the maxilla and mandible andTo evaluate growth and displacement of the maxilla and mandible and
to register the movements of the upper and lower molars and incisors,to register the movements of the upper and lower molars and incisors,
JohnstonJohnston developed his Pitchfork Analysis. Growth or displacementdeveloped his Pitchfork Analysis. Growth or displacement
of maxilla and mandible are measured relative to the cranial base (SEof maxilla and mandible are measured relative to the cranial base (SE
registration). The changes in the upper and lower incisors areregistration). The changes in the upper and lower incisors are
measured relative to basal bone. The dental and skeletalmeasured relative to basal bone. The dental and skeletal
measurements were executed parallel to the mean functional occlusalmeasurements were executed parallel to the mean functional occlusal
plane (MFOP) and each was given a sign appropriate to its impact onplane (MFOP) and each was given a sign appropriate to its impact on
molar or overjet correction.molar or overjet correction.
Positive-Positive- if it improved the relationship (as with forward growth ofif it improved the relationship (as with forward growth of
the mandible/distal movement of maxillary molars and incisors).the mandible/distal movement of maxillary molars and incisors).
Negative-Negative- if it made them worse (eg. forward growth of the maxillaif it made them worse (eg. forward growth of the maxilla
or mesial movement of the maxillary dentition.)or mesial movement of the maxillary dentition.)

Using the Bjork's method of superimposition the following were found:
Mandibular symphyseal movement relative to maxilla,
The displacement (as a result of growth, orthopedic changes, or
functional shift) of maxillary and mandibular basal bone relative
to cranial base.
The movement of the first molars (measured at the mesial contact
point and at a point midway between the apices) and central incisors
(at the incisal edge) relative to basal bone.

CEPHALOMETRICS IN TREATMENT PLANNINGCEPHALOMETRICS IN TREATMENT PLANNING::
Effective treatment planning in depends on accurate diagnosis.Effective treatment planning in depends on accurate diagnosis.
*In cases of malocclusion due to muscular dysfunction some times*In cases of malocclusion due to muscular dysfunction some times inhibition therapyinhibition therapy isis
suggested. Cephalometeric radiography makes its possible to judge whether aftersuggested. Cephalometeric radiography makes its possible to judge whether after
elimination of the dysfunction the growth trend is likely-to be normalelimination of the dysfunction the growth trend is likely-to be normal..
*Similarly the*Similarly the indication of activatorindication of activator therapy can be determined usingtherapy can be determined using
cephalometrics:cephalometrics:
Three conditions are essentialThree conditions are essential
1)SNB small -suggesting a small mandible1)SNB small -suggesting a small mandible
2)Growth pattern is horizontal2)Growth pattern is horizontal
3)SNA normal - maxilla in normal position3)SNA normal - maxilla in normal position
**Cervical headgear therapyCervical headgear therapy is indicated when SNA is large with anteinclination ofis indicated when SNA is large with anteinclination of
maxilla (large J angle.)maxilla (large J angle.)
**Discrepancy calculationDiscrepancy calculation is made to determine the amount of space available and thatis made to determine the amount of space available and that
required. It is done models and radiographs. On radiographs, the distance from therequired. It is done models and radiographs. On radiographs, the distance from the
lower incisor to N-Pog line is determined. This is the sagittal discrepancy.(SD). Totallower incisor to N-Pog line is determined. This is the sagittal discrepancy.(SD). Total
discrepancy (TD) is calculated from SD & DD (Dental Discrepancy which isdiscrepancy (TD) is calculated from SD & DD (Dental Discrepancy which is
calculated from a model.calculated from a model.
TD = SD + ½ DDTD = SD + ½ DD
Treatment is planned so that the lower incisors are not more than 4mm anterior to theTreatment is planned so that the lower incisors are not more than 4mm anterior to the
N-Pog line.N-Pog line.

*Planning Anchorage*Planning Anchorage -three degrees of anchorage are-three degrees of anchorage are
found.found.
Minimal AnchorageMinimal Anchorage is needed when lower incisors are veryis needed when lower incisors are very
upright and behind N-Pog line.upright and behind N-Pog line.
Moderate AnchorageModerate Anchorage is needed when lower incisors afteris needed when lower incisors after
treatment will be 2-4mm anterior to N-Pog line.treatment will be 2-4mm anterior to N-Pog line.
Maximum AnchorageMaximum Anchorage is needed when lower incisors afteris needed when lower incisors after
treatment will be 4mm anterior to N-Pog line.treatment will be 4mm anterior to N-Pog line.

P-A View
Frontal view is particularly important in cases of dentoalveolar & facial
asymmetry, crossbites and functional mandibular displacements.
There are different methods of analysis -
1)Rickett ‘s- measures the nasal cavity width, maxillary, mandibular,
intermolar & intercuspid widths by connecting bilateral identical points and
measuring the distance between them. Symmetry is measured from the
mid-sagittal plane and relating the points pogonion and ANS to it.
2)Svanholt and Solow analysis- it measures the relationships between the
midlines of the jaws and dental arches. It measures the transverse
maxillary and mandibular positions, transverse jaw relationship, position of
upper and lower incisors and the compensation of upper and lower incisors.
It incorporates variables that will be zero in symmetrical subjects.
3)Grayson analysis- it uses multiple planes at selected depths to analyse facial
asymmetry.
4)Hewitt analysis- it is performed by dividing the craniofacial complex into
constructed triangles-triangulation of face
5)Chierici analysis- focuses on asymmetry of upper face.
6)Grummon 's analysis

COGS (CEPHALOMETRIES FOR ORTHOGNATHIC SURGERY)
It was developed by Burstone and Legan. Normally during orthodontic
treatment, the alveolar base is stable. But during orthognathic
surgery, the alveolar base also changes position. The COGS system
describes the horizontal and vertical position of facial bones by use
of a constant coordinate system.
1. The chosen landmarks and measurements can be altered by various
surgical procedures.
2. The comprehensive appraisal includes all of the facial bones and a
cranial base reference.
3. Rectilinear measurements can be readily transferred to a study
cast for mock surgery.
4. Critical facial skeletal components are examined.
5. Standards and static's are available for variations in age and sex.
6. Systematised approach to measurements that can be computerised.
7. COGS appraisal describes dental, skeletal and soft tissue
variations.

PHOTOCEPHALOMETRY
It is an attempt to obtain a more accurate and detailed information of the
soft tissues in head views by superimposing co-ordinated head films with
photographs. !t was developed for patients requiring orthognathic surgery.
The assumption behind this technique is that the photographic images can be
enlarged so that metal markers placed on the patient's skin are accurately
superimposed on the corresponding radio opaque images on the cephalogram.
The benefits are
~ A more detailed visualisation of the soft tissues in the frontal and lateral
views.
~ A more accurate analysis of soft and hard tissue relationships,
particularly of soft tissue thickness.
There are 2 errors inherent in this method
~ Magnification distortion errors in superimposition of photographic
cephalometric image.
~ Landmark identification
The photocephalometric apparatus is simply-.an adaptation of the standard
cephalometric set-up

DIGIGRAPH
A software product Digigraph enables clinicians to
perform non-invasive and non-radiographic cephalometric
analysis. This device uses sonic digitizing electronics to
record cephalometric landmarks by lightly touching the
sonic digitising probe to the patient and pressing the
probe button. The probe emits a sound and the
corresponding landmark is recorded sonically by the
microphone array. Using this cephalometric analysis and
monitoring of the patient's treatment progress is
performed as often as desired without radiation exposure.
Also data collection is non-invasive and efficient. It is
very useful in quatifying facial asymmetries.

DIGITAL COMPUTED RADIOGRAPHY SYSTEM (CR)
CR system operates with a punctiform X-ray beam which
stimulates a 2-D memory sensor, in the space of only
1/100 th of a second. This memorised data is converted
into electrical signal and then to a numerical 2-D image
consisting pixels. The image is then enhanced by
multiplying the value of each pixel and modifying the
relationships between values of the pixels making up a
certain area. This helps in varying the type of response
that can be obtained from the detector.
The imaging plate (analogous to a film), temporarily stores
the X-ray energy and then emits it when scanned with a
He-Ne laser. The blue light emitted is converted to an
electrical signal which is read by the image reader. These
signals are amplified and logarithmically converted before
being transmitted through an analogical-digital converter
which converts them to digital signals.
.........contd..........contd.www.indiandentalacademy.com

Advantages
>- Surpass conventional analogical radiology.
>- Reduces radiation exposure by 28.6% for PA view and 58.4% for
lateral Cephalometry.
>- Converts information to digital signals (digital imaging) and
enhanced information.
>- Provide more sensitive, higher definition images.
>- Optimisation of processing of images in terms of contrast,
gradation, sharpness and granulosity, enhancing the diagnostic
significance of the information.
>- Process images to enable establishment of databases.
>- Remote image transmission
>- Increased reliability and accuracy
>- Wide latitude.
>- Modulation of the images (enlarging/reducing/changing contrast) is
possible.

COMPUTERISED CEPHALOMETRICS
This has two components- data acquisition and data management.
X-ray beam attenuation is recorded directly and converted to a
digital image. Sonic technology is also used nowadays. A variety of
soft ware programmes are available ( like Por Dios, Dentofacial
planner, etc. ) which use one of the pre-programmed analysis. They
also allow superimposition, estimation of growth, simulation of
orthodontic tooth movement, etc.
Advantages -
>it is very fast.
>It is only necessary to digitise the points directly on the
cephalogram and calculations are done in seconds.
>It removes human error
>Facilitates use of double digitisation of landmarks, thus increasing
reliability.
>Easy storage and retrieval of values.

►Conclusion:Conclusion:

Role of cephalometry in orthdodontics

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Role of cephalometry in orthdodontics