Cephalometrics
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
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Cephalometrics
History, Evolution,
Landmarks
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Introduction
 Ever since God created man he is trying
to change his image.
 Attempts to change facial appearance are
rec...
 Orthodontists, in their attempts to
change facio-oro-dental deviations from
accepted norms, have adopted
cephalometric m...
 Cephalometry developed from craniometry.
 Craniometry is defined as “the art of
measuring skulls of animals so as to
di...
 Cephalometry is concerned with
measuring the head inclusive of soft
tissues, be it living or dead.
 Craniometry – measu...
 With the discovery of X rays by Roentgen
in 1895, Radiographic Cephalometry
came in to being.
 Defined as the measureme...
This approach combines the
advantages of Craniometry and
anthropometry.
The disadvantage is that it produces
two dimensi...
History
 History prior to the advent of
radiography begins with the attempts of
the scientists to classify the human
phys...
 In 500 BC, Hippocrates, Father of
medicine, designated two physical types
1.Habitus phithicus -- long thin body
subject ...
 Sheldon continued the work & refined it.
 He classified physique in to three types.
1.Endomorphy is centered on the
abd...
 He discovered that these three
fundamental elements which, when
combined together, made up all these
physiques or somato...
 Somatotype is defined as a quantified
expression and description of the
present morphological conformation of
a person.
...
 Extreme physique types
- Endomorph (rounded, 7-1-1).
- Mesomorph (muscular, 1-7-1).
- Ectomorph (angular, 1-1-7).
Typica...
 Sheldon's Temperament Types:
Temperament is body type in
action.
 Endotonia is seen in the love of relaxation,
comfort,...
History of measurements
and proportions
 Portrayal of human form demands not
only artistic talent & technical ability but...
 Initially the canons were enclosed in a grid
system of equalized squares with 18 horizontal
lines, line 18 drawn through...
Period of Renaissance
 Leonardo da vinci was probably the
earliest to apply the theory of head
measurement.
 He used lin...
 His drawings included a study of facial
proportions in natural head position.
The profile was divided in to seven parts
...
 Albrecht Durer, published a treatise in
1528 on cranial measurements which
comprised the “Vier Bucher von
menschliche Pr...
 The sixteenth century saw the first truly
scientific attempt at cranial
measurement & the introduction by
Spigel of the ...
 Facial: from the most inferior point of the chin to
the most superior point on the forehead.
 Occipital: from the crown...
 The Dutchman Pieter Camper was credited
with the introduction of facial angle.
 He oriented crania on a horizontal from...
 The facial angle as he described was
formed by the intersection of a facial line
and a horizontal plane.
 The facial li...
 The horizontal plane passes through the
lower part of the nasal aperture,
backwards along the line of the
zygomatic arch...
 The terms prognathic and orthognathic
introduced by Retzius are tied to
Camper‟s illustrations of facial form.
 As a re...
Drawbacks of Camper’s facial angle were:
 Ignores the contribution made by the lower
jaw to facial forms.
 No strict adh...
 Deschamps introduced cephalic
triangle made up of facial, occipital, &
coronal angles.
 Facial angle was formed by the
...
 Similar to Camper‟s facial angle. The use
of external auditory meatus as a
reference point enabled a rough
comparison to...
 Anders Retzius correlated the two
schemes, i.e., of Camper and
Blumenbach, thereby providing a basis
for the methods of ...
 19th century produced 3 great men in history of
craniology: Huxley, Broca & Topinard.
 Thomas Huxley wrote that “the so...
 Broca -- founder of Paris Society of
Anthropology.
 He introduced a base line “plan alveolo-
condylien” which passes th...
 Paul Topinard used a similar craniostat
with some additional modifications.
 “The craniometer substitutes the
mathemati...
 As standardization became the buzz word
in craniometry the
13th General Congress of the German
Anthropological Society m...
 The FHP is modified from the Baer‟s
horizontal which passed through the
zygomas, and a refinement of
Von Ihering‟s horiz...
 However the reproducibility of this plane
on an intact skull is less than Broca‟s
condyloalveolar plane.
 It is now tak...
History of Cephalometric
Radiography
 In 1895, Prof. Wilhelm Conrad Roentgen
made a remarkable contribution to science
wi...
 Prof. Wilhem Koening & Dr. Otto
Walkhoff simultaneously made the first
dental radiograph in 1896.
 It was clear that th...
 Van Loon -- first to introduce
cephalometrics to orthodontics. He applied
anthropometric procedures in analyzing
facial ...
 The first x- ray pictures of skull in the
standard lateral view were taken by
A.J.Pacini & Carrera in 1922.
 Pacini rec...
 Pacini introduced a teleroentgenographic
technique for standardized lateral head
radiography which proved to be of
treme...
 The head of the subject, placed adjacent
to a standard holding the cassette, was
immobilized with a gauze bandage
wrappe...
 Atkinson in 1922 advocated the use of
roentgenograms in locating the „key
ridge‟ and the soft tissue relations to the
fa...
 In 1931 cephalometric radiography came
to full function when B. Holly Broadbent
in USA published methods to obtain
stand...
 The interesting fact is that Broadbent
was an Orthodontist, whereas Hofrath
was a Prosthodontist.
 This development ena...
Broadbent’s contribution
 Broadbent‟s interest in craniofacial growth
began with his orthodontic education
under E.H. Ang...
 The diagnosing dental deformities by
means of planes & angles was first
proposed in 1922 by Paul Simon in his
book, “Fun...
 During 1920‟s Broadbent refined the
craniostat in to craniometer by the
addition of metric scales.
 That proved to be t...
 The patient‟s head was centered in the
cephalostat with the superior borders of
the external auditory meatus resting on
...
 The lowest point on the inferior bony
border of the left orbit, indicated by the
orbital marker, was at the level of the...
 The focus film distance was set at 5 feet
(152.4 cm) and the subject film distance
could be measured to calculate image
...
 Hofrath‟s technique differed from
Broadbent‟s in that the path of the
central ray was not fixed in relation to
the head ...
 In 1937, using serial records of twins;
Broadbent showed how growth – or its
lack – was the greatest limiting factor in
...
 Brodie, in a landmark study, corroborated
Broadbent‟s contention that the growth
pattern of the normal child‟s face
deve...
Thompson and Brodie in a report on the
rest position of the mandible, concluded
that:
 The morphogenetic pattern of the h...
 Margolis (1943) wrote on the relationship
between the inclination of the lower incisor
and the incisor-mandibular plane ...
Cephalometric
Analysis
 The major use of radiographic
cephalometry is in characterizing the
patient‟s dental and skeletal...
 William. B. Downs in 1948 developed the
first cephalometric analysis.
 Its significance was that it presented an
object...
Evolution of
Cephalometrics
 The thoroughness of Broadbent‟s design of
the cephalometric method is evident from
the fact ...
Patient Orientation
 The ears are used as the basis for
orientation & fixation of the patient in the
beam axis.
 FH plan...
But the FHP also had its drawbacks :
 Some individuals show a variation of
their FH plane to the true horizontal to
an ex...
 An alternative to overcome this problem
was to use a functionally derived NHP.
 Obtained by asking the subject to look ...
X-Ray Source Position
 The x-ray is positioned 5 feet (152.4 cm)
from the subject‟s midsagittal plane. A
change to 150 cm...
Film Position &
Enlargement
 Other significant change from original
technique is adjustability of film position.
 The or...
 The disadvantage of this very efficient
mechanical design is that it makes
cassette position and resultant
enlargement d...
 The relative immunity of angular
measurements to enlargement
distortions led researchers to opt for
angular over linear ...
Postero-Anterior
(Frontal)
Cephalometry
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PA Cephalometry
 Since the introduction of a standardized
method for obtaining skull radiographs,
cephalometrics has beco...
 PA Ceph allows to evaluate the width and
angulation of the dental arches to their
osseous bases in the transverse plane....
 A cephalostat that can be rotated 90° is
used, so that the central beam passes the
skull in a postero anterior direction...
 In using NHP for PA ceph, the practical
problem encountered is that the patient
facing the cassette makes it difficult f...
 As far as exposure is considered, more
exposure is needed for PA cephalograms
than lateral views (Enlow).
 For better e...
 In cases of suspected significant
mandibular displacement, the PA
cephalogram should be taken with the
mouth of the pati...
Cephalometric
Landmarks
 -- are readily recognizable points on a
cephalometric radiograph or tracing,
representing certai...
Requirements
 Should be easily seen on the roentgenogram,
 Be uniform in out line, and easily reproducible.
 Should hav...
 Garn -- there are no „fixed points‟ in the
skull of living person. Depends on age,
sex, maturation rate, ethnic backgrou...
Landmarks in Lat.Ceph
Hard tissue landmarks
 A-point (Point A, Subspinale, SS) : the
deepest (most posterior) midline poi...
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 Articulare (Ar) : constructed point
representing the intersection of three
radiographic images: the inferior surface
of ...
 Basion (Ba): the most anterior inferior
point on the margin of the foramen
magnum in the midsagittal plane.
 Bolton (Bo...
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 Clinoidale (Cl) : most superior point on the
contour of anterior clinoid -- Usu unilateral.
 Condylion (Co) : the most ...
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 Gnathion (Gn) : the most anterior inferior
point on the bony chin in the midsagittal
plane.
 Gonion (Go): the most post...
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 Infradentale (Id) : the most superior
anterior point on the mandibular alveolar
process between the central incisors.
 ...
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 Menton (Me) : the most inferior point of
the mandibular symphysis in the
midsagittal plane.
 Nasion (N,Na) : the inters...
 Orbitale (Or) : the lowest point on the
inferior orbital margin
 Pogonion (pog, P, Pg) : the most anterior
point on the...
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 Posterior nasal spine (PNS) : the most
posterior point on the bony hard palate in
the midsagittal plane, the meeting poi...
 Pterygomaxillary fissure (PTM,) :
bilateral inverted tear drop shaped
radiolucency whose anterior border
represents the ...
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Soft Tissue Landmarks
 Cervical point (C) : the innermost point
between the submental area and the
neck in the midsagitta...
 Inferior labial sulcus (Ils) : point of
greatest concavity on the contour of the
lower lip between the labrale inferius ...
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 Pronasale (Pn) : most prominent point of
the tip of the nose, in the midsagittal
plane.
 Soft tissue glabella (G’) : mo...
 Soft tissue nasion (N’, Na’) : deepest
point of the concavity between the
forehead and the soft tissue contour of
the no...
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 Stomion (St) : most anterior point of
contact between the upper and lower lip in
the midsagittal plane. When the lips ar...
 Subnasale (Sn) : point in the midsagittal
plane where the base of the columella of
the nose meets the upper lip.
 Super...
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PA Ceph
Bilateral Skeletal Landmarks
 Greater Wing Superior Orbit (GWSO) -
the intersection of the superior border of
the...
 Lesser Wing Orbit (LWO) - the
intersection of the superior border of the
lesser wing of the sphenoid bone and
medial asp...
 Medial Orbit (MO) - the midpoint of the
medial orbital margin.
 Superior Orbit (SO) - the midpoint of
the superior orbi...
S
o
So
OO
M
o
Lo
Zf
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 Zygomatic (Z) - the most lateral aspect of
the zygomatic arch.
 Foramen Rotundum (FR) - the center of
foramen rotundum....
 Mastoid Process (MP) - the most inferior
point on the mastoid process.
 Malar (M) - the deepest point on the
curvature ...
 Mandible/Occiput (MBO) - the
intersection of the mandibular ramus and
the base of the occiput.
 Gonion (G) - the midpoi...
Cs
Cc
Z
Mp
G
Ag
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Midline Skeletal
Landmarks
 Crista Galli (CG) - the geometric center
of the crista galli.
 Sella Turcica (ST) - the most...
 Nasal Septum (NSM) - the approximated
midpoint on the nasal septum between
crista galli and the anterior nasal spine.
 ...
 Incisor Point (IPL) - the crest of the
alveolus between the mandibular central
incisors.
 Genial Tubercles (GT) - the c...
Bilateral Dental Landmarks
 Maxillary Cuspid (MX3) - the incisal tip of
the maxillary cuspid.
 Maxillary Molar (MX6) - t...
 Mandibular Cuspid (MD3) - the incisal
tip of the mandibular cuspid.
 Mandibular Molar (MD6) - the midpoint
on the bucca...
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Identification And
Reproducibility
 Cephalometric measurements are
subject to errors that may be caused by
radiographic p...
 Identification errors are considered as the
major source of cephalometric error.
Factors involved are:
 Density & sharp...
 To determine the reproducibility of some
commonly used 15 landmarks. A Meta
analysis was carried out by B. Tipkova, P.
M...
 It was concluded that some landmarks
are more reproducible in a horizontal
direction and others in a vertical
direction....
Identification error in PA
(Frontal) Ceph
 Paul W. Major, Donald E. Johnson and
Karen L. Hesse conducted a study which
wa...
 The horizontal and vertical identification
errors were determined for a sample of
33 skulls and 25 patients.
 Interexam...
 Baumrind and Frantz pointed out that
there are 2 classes of errors associated
with cephalometrics. The first is
“project...
 Landmarks on a sharp curve or at the
intersection of curves are generally
identified easily than points located on
flat ...
Conclusion
 Broadbent‟s gave us a three dimensional
analysis, but orthodontics has remained
preoccupied with the lateral ...
 Clinical orthodontics is yet to fully utilize
Broadbent‟s contribution.
 We treat in three dimensions and the width
dim...
Broadbent
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Ceph (3) /certified fixed orthodontic courses by Indian dental academy

  1. 1. Cephalometrics INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Cephalometrics History, Evolution, Landmarks www.indiandentalacademy.com
  3. 3. Introduction  Ever since God created man he is trying to change his image.  Attempts to change facial appearance are recounted throughout recorded history.  The question of what is a normal face? what constitutes beauty? will probably never be answered.www.indiandentalacademy.com
  4. 4.  Orthodontists, in their attempts to change facio-oro-dental deviations from accepted norms, have adopted cephalometric measurement, a method employed in physical anthropology.  Cephalometric radiography was introduced in to orthodontics during the 1930s. www.indiandentalacademy.com
  5. 5.  Cephalometry developed from craniometry.  Craniometry is defined as “the art of measuring skulls of animals so as to discover their specific differences”.  For many years anatomists and anthropologists were confined to measuring craniofacial dimensions using the skull of dead individuals. www.indiandentalacademy.com
  6. 6.  Cephalometry is concerned with measuring the head inclusive of soft tissues, be it living or dead.  Craniometry – measuring skull.  Cephalometry – measuring head.  However Cephalometry had its limitations due to the inaccuracies that resulted from varying thickness of soft tissues. www.indiandentalacademy.com
  7. 7.  With the discovery of X rays by Roentgen in 1895, Radiographic Cephalometry came in to being.  Defined as the measurement of head from bony and soft tissue land marks on the radiographic image (Krogman & Sassouni 1957). www.indiandentalacademy.com
  8. 8. This approach combines the advantages of Craniometry and anthropometry. The disadvantage is that it produces two dimensional image of a three dimensional structure. www.indiandentalacademy.com
  9. 9. History  History prior to the advent of radiography begins with the attempts of the scientists to classify the human physiques.  Basically it stems from the history of Anthropometry. www.indiandentalacademy.com
  10. 10.  In 500 BC, Hippocrates, Father of medicine, designated two physical types 1.Habitus phithicus -- long thin body subject to tuberculosis, & 2.Habitus applecticus -- short thick individual susceptible to vascular diseases & apoplexy.  Kretschmer (1921) described : pyknic (compact), asthenic (without strength), & athletic. www.indiandentalacademy.com
  11. 11.  Sheldon continued the work & refined it.  He classified physique in to three types. 1.Endomorphy is centered on the abdomen, and the whole digestive system. 2.Mesomorphy is focused on the muscles and the circulatory system. 3.Ectomorphy is related to the brain and the nervous system. www.indiandentalacademy.com
  12. 12.  He discovered that these three fundamental elements which, when combined together, made up all these physiques or somatotypes.  He worked out ways to measure these three components and to express them numerically so that every human body could be described in terms of three numbers. www.indiandentalacademy.com
  13. 13.  Somatotype is defined as a quantified expression and description of the present morphological conformation of a person.  It is independent of size, age and gender  Denoted as x-y-z. (endo – meso – ecto). Min – 1, Max – 7. www.indiandentalacademy.com
  14. 14.  Extreme physique types - Endomorph (rounded, 7-1-1). - Mesomorph (muscular, 1-7-1). - Ectomorph (angular, 1-1-7). Typical - males (3-4-4) - females (5-3-3) Meso Endo Ecto www.indiandentalacademy.com
  15. 15.  Sheldon's Temperament Types: Temperament is body type in action.  Endotonia is seen in the love of relaxation, comfort, food and people.  Mesotonia is centered on assertiveness and a love of action.  Ectotonia focuses on privacy, restraint and a highly developed self-awareness. www.indiandentalacademy.com
  16. 16. History of measurements and proportions  Portrayal of human form demands not only artistic talent & technical ability but a disciplined & consistent style.  The ancient Egyptians developed an intricate quantitative system that defined the proportions of the human body. It became known as the Canon of proportions. www.indiandentalacademy.com
  17. 17.  Initially the canons were enclosed in a grid system of equalized squares with 18 horizontal lines, line 18 drawn through hairline.  Later it was included in a grid system of 22 horizontal lines, line 21 drawn through the upper eyelid. www.indiandentalacademy.com
  18. 18. Period of Renaissance  Leonardo da vinci was probably the earliest to apply the theory of head measurement.  He used lines related to specific structures in the head in his study of human form. www.indiandentalacademy.com
  19. 19.  His drawings included a study of facial proportions in natural head position. The profile was divided in to seven parts by eight horizontal lines.  The joining of the lower lip and chin and the tip of the jaw and the upper tip of the ear with the temple forms a perfect square; and each face is half of the head. www.indiandentalacademy.com
  20. 20.  Albrecht Durer, published a treatise in 1528 on cranial measurements which comprised the “Vier Bucher von menschliche Proportion”.  Using geometrical methods he provided a analysis of the leptoprosopic face & euryprosopic face in coordinate system, where the horizontal and the vertical lines were drawn through the same land marks or facial features. www.indiandentalacademy.com
  21. 21.  The sixteenth century saw the first truly scientific attempt at cranial measurement & the introduction by Spigel of the “lineae cephalometricae”.  Spigel‟s linear cephalometricae consisted of four lines: the facial, occipital, frontal, & sincipital lines. www.indiandentalacademy.com
  22. 22.  Facial: from the most inferior point of the chin to the most superior point on the forehead.  Occipital: from the crown of the head to atlas.  Frontal: from one temple to the other.  Sincipital: from the lowest part of the ear, to the highest part of the sinciput -- the anterior part of the head or skull from forehead to the crown.  According to him in a well proportioned skull, these lines should all be equal to one another. www.indiandentalacademy.com
  23. 23.  The Dutchman Pieter Camper was credited with the introduction of facial angle.  He oriented crania on a horizontal from the middle of porus acusticus to a point below the nose. Camper‟s horizontal became the reference line for angular measurements used to characterize evolutionary trends in anthropological studies. www.indiandentalacademy.com
  24. 24.  The facial angle as he described was formed by the intersection of a facial line and a horizontal plane.  The facial line was a line tangential to the most prominent part of the frontal bone and to the slight convexity anterior to the upper teeth. www.indiandentalacademy.com
  25. 25.  The horizontal plane passes through the lower part of the nasal aperture, backwards along the line of the zygomatic arch, and through the centre of the external auditory meatus.  Camper‟s facial angle was readily accepted as a standard measurement in craniology. www.indiandentalacademy.com
  26. 26.  The terms prognathic and orthognathic introduced by Retzius are tied to Camper‟s illustrations of facial form.  As a result the facial angle became a time honored anthropological method to determine the facial type.  Prognathism refers to the prominence of jaws, relative to forehead, & a straight facial profile -- as orthognathous. www.indiandentalacademy.com
  27. 27. Drawbacks of Camper’s facial angle were:  Ignores the contribution made by the lower jaw to facial forms.  No strict adherence to location of posterior reference point for the horizontal plane.  Direct comparison of skull of different ages was not possible because the locating point might alter its position with age. www.indiandentalacademy.com
  28. 28.  Deschamps introduced cephalic triangle made up of facial, occipital, & coronal angles.  Facial angle was formed by the intersection of a horizontal that passed from the external auditory meatus to the base of the nose, which crossed the profile line. www.indiandentalacademy.com
  29. 29.  Similar to Camper‟s facial angle. The use of external auditory meatus as a reference point enabled a rough comparison to be made between skulls.  An antagonist of Camper, Johann Friedrich Blumenbach rejected the use of lines & angles as a test of universal characteristics & proposed a minute survey of the skull particularly the frontal and maxillary bones. www.indiandentalacademy.com
  30. 30.  Anders Retzius correlated the two schemes, i.e., of Camper and Blumenbach, thereby providing a basis for the methods of craniology used today.  He is also credited with the introduction of cephalic index, the ratio of breadth to length of the skull expressed as a percentage. www.indiandentalacademy.com
  31. 31.  19th century produced 3 great men in history of craniology: Huxley, Broca & Topinard.  Thomas Huxley wrote that “the so called facial angle, is the product of two factors, a facial & a cranial, which vary independently.  He also introduced two new angles, the spheno maxillary and spheno ethmoidal angles. He preferred the spheno maxillary angle to Camper‟s angle when comparing the degree of prognathism in different skulls. www.indiandentalacademy.com
  32. 32.  Broca -- founder of Paris Society of Anthropology.  He introduced a base line “plan alveolo- condylien” which passes through the alveolar point & tangential to the inferior surfaces of the two occipital condyles.  He developed craniostat, constructed of wood for positioning the skull. www.indiandentalacademy.com
  33. 33.  Paul Topinard used a similar craniostat with some additional modifications.  “The craniometer substitutes the mathematical data for the uncertain data founded on judgment & opinion”.  It studies the skeleton, the cranium & the face separately and each of the plates as well. www.indiandentalacademy.com
  34. 34.  As standardization became the buzz word in craniometry the 13th General Congress of the German Anthropological Society met at Frankfurt-am-Maine in August 1882.  It is to this Congress that the Frankfurt Horizontal Plane owes its name. www.indiandentalacademy.com
  35. 35.  The FHP is modified from the Baer‟s horizontal which passed through the zygomas, and a refinement of Von Ihering‟s horizontal.  Von Ihering‟s – plane passes through the centre of auditory meatus to the lower point on the inferior margin of orbit.  FHP -- plane passes through the upper border of the bony meatus vertically above their centres. www.indiandentalacademy.com
  36. 36.  However the reproducibility of this plane on an intact skull is less than Broca‟s condyloalveolar plane.  It is now taken as passing through the right and left porion &left orbitale. Thereby reducing the problems incurred by asymmetrical skulls. www.indiandentalacademy.com
  37. 37. History of Cephalometric Radiography  In 1895, Prof. Wilhelm Conrad Roentgen made a remarkable contribution to science with the discovery of x-rays.  On December 28, 1895 he submitted a paper “On A New Kind of Rays, A Preliminary Communication” to the Wurzburg Physical Medical Society. www.indiandentalacademy.com
  38. 38.  Prof. Wilhem Koening & Dr. Otto Walkhoff simultaneously made the first dental radiograph in 1896.  It was clear that the use of x-rays provided the means of obtaining a different perspective on the arrangement and relation of bones thus expanding the horizons of craniometry & cephalometry . www.indiandentalacademy.com
  39. 39.  Van Loon -- first to introduce cephalometrics to orthodontics. He applied anthropometric procedures in analyzing facial growth by making plaster casts of face in to which he inserted oriented casts of the dentition.  Hellman in 1920s used cephalometric techniques and described their value. www.indiandentalacademy.com
  40. 40.  The first x- ray pictures of skull in the standard lateral view were taken by A.J.Pacini & Carrera in 1922.  Pacini received a research award from the American Roentgen Ray Society for a thesis entitled “Roentgen Ray Anthropometry of the Skull”. www.indiandentalacademy.com
  41. 41.  Pacini introduced a teleroentgenographic technique for standardized lateral head radiography which proved to be of tremendous use in cephalometry, as well as in measuring growth and dev of face.  His method, which was rather primitive, involved a large fixed distance from the x ray source to the cassette. www.indiandentalacademy.com
  42. 42.  The head of the subject, placed adjacent to a standard holding the cassette, was immobilized with a gauze bandage wrapped around both the face and the cassette.  He identified the following landmarks : gonion, pogonion, nasion, and anterior nasal spine. He also located the sella turcica & external auditory meatus. www.indiandentalacademy.com
  43. 43.  Atkinson in 1922 advocated the use of roentgenograms in locating the „key ridge‟ and the soft tissue relations to the face and the jaws.  In 1923 Mc Cowen reported that he used profile roentgenograms for orthodontic purposes to visualize the relationship between the hard and soft tissues and to note changes in profile which occur during treatment. www.indiandentalacademy.com
  44. 44.  In 1931 cephalometric radiography came to full function when B. Holly Broadbent in USA published methods to obtain standardized head radiographs in the Angle Orthodontist (A new X ray tech & its application to orthodontia).  H. Hofrath simultaneously published the same in Fortschritte der Orthodontie in Germany. www.indiandentalacademy.com
  45. 45.  The interesting fact is that Broadbent was an Orthodontist, whereas Hofrath was a Prosthodontist.  This development enabled orthodontists to capture the field of cephalometry from the anatomists and anthropologists. www.indiandentalacademy.com
  46. 46. Broadbent’s contribution  Broadbent‟s interest in craniofacial growth began with his orthodontic education under E.H. Angle in 1920.  He continued to pursue that interest along with his orthodontic practice, working with a leading anatomist J. Wingate Todd www.indiandentalacademy.com
  47. 47.  The diagnosing dental deformities by means of planes & angles was first proposed in 1922 by Paul Simon in his book, “Fundamental Principles of a Systematic Diagnosis of Dental Anomalies”.  Although his “Law of the Canines” was later disproved by Broadbent, his theories stimulated Broadbent to apply the principles of craniometry to living subjects. www.indiandentalacademy.com
  48. 48.  During 1920‟s Broadbent refined the craniostat in to craniometer by the addition of metric scales.  That proved to be the first step in the evolution of craniostat in to a radiographic cephalostat. www.indiandentalacademy.com
  49. 49.  The patient‟s head was centered in the cephalostat with the superior borders of the external auditory meatus resting on the upper parts the two ear rods. www.indiandentalacademy.com
  50. 50.  The lowest point on the inferior bony border of the left orbit, indicated by the orbital marker, was at the level of the upper parts of the ear rods.  Nose clamp was fixed at the root of the nose to support the upper face. www.indiandentalacademy.com
  51. 51.  The focus film distance was set at 5 feet (152.4 cm) and the subject film distance could be measured to calculate image magnification.  With the two X ray tubes at right angles to each other in the same horizontal plane, two images (lateral & PA) could be simultaneously produced. www.indiandentalacademy.com
  52. 52.  Hofrath‟s technique differed from Broadbent‟s in that the path of the central ray was not fixed in relation to the head and no plan was suggested for super positioning subsequent x-rays. www.indiandentalacademy.com
  53. 53.  In 1937, using serial records of twins; Broadbent showed how growth – or its lack – was the greatest limiting factor in clinical success.  In 1943 he stipulated that eruption of the third molars had no ill effect on the denture, particularly the lower incisors. www.indiandentalacademy.com
  54. 54.  Brodie, in a landmark study, corroborated Broadbent‟s contention that the growth pattern of the normal child‟s face develops in an orderly downward and forward fashion and that the pattern, once attained at an early age, did not change. www.indiandentalacademy.com
  55. 55. Thompson and Brodie in a report on the rest position of the mandible, concluded that:  The morphogenetic pattern of the head was established at a very early age and did not change.  The presence or absence of teeth has little bearing on the form or the rest position of the mandible.  Vertical facial proportions are constant throughout life.www.indiandentalacademy.com
  56. 56.  Margolis (1943) wrote on the relationship between the inclination of the lower incisor and the incisor-mandibular plane angle.  First to corroborate Tweed‟s clinical observation that, in normal occlusions, the lower incisors are 90° to the mandibular basal bone.  In 1947 Margolis contributed his maxillo- facial triangle. www.indiandentalacademy.com
  57. 57. Cephalometric Analysis  The major use of radiographic cephalometry is in characterizing the patient‟s dental and skeletal relationships.  This led to the development of a number of cephalometric analyses to compare a patient to the population standards. www.indiandentalacademy.com
  58. 58.  William. B. Downs in 1948 developed the first cephalometric analysis.  Its significance was that it presented an objective method of portraying many factors underlying malocclusion.  Followed by other analyses by Steiner (1953), Tweed (1953), Ricketts (1958), Sassouni (1969), Enlow (1969), Jaraback (1970), Jacobson (1975) etc. www.indiandentalacademy.com
  59. 59. Evolution of Cephalometrics  The thoroughness of Broadbent‟s design of the cephalometric method is evident from the fact that the basic technique has survived unchanged for over 70 years.  The instrumentation had evolved to a more suitable form for the individual practitioner through the pioneering efforts of Margolis, Higley & others. www.indiandentalacademy.com
  60. 60. Patient Orientation  The ears are used as the basis for orientation & fixation of the patient in the beam axis.  FH plane was adopted for horizontal orientation with nasion for stabilization.  FH plane was chosen because this approximates the natural head position. www.indiandentalacademy.com
  61. 61. But the FHP also had its drawbacks :  Some individuals show a variation of their FH plane to the true horizontal to an extent of ± 10°. (Avg – 7o)  The landmarks to locate the FH plane, orbitale & porion, are difficult to identify on a cephalogram. www.indiandentalacademy.com
  62. 62.  An alternative to overcome this problem was to use a functionally derived NHP.  Obtained by asking the subject to look at the image of their eyes in the mirror located at eye level. (Morrees & Kean).  Functionally derived NHP was more accurate but its reproducibility was less than FHP (anatomic approx of NHP). www.indiandentalacademy.com
  63. 63. X-Ray Source Position  The x-ray is positioned 5 feet (152.4 cm) from the subject‟s midsagittal plane. A change to 150 cm has been adopted by some, but the difference is negligible.  A major improvement in cephalostats is the capability of taking both lateral & PA views with a single x-ray source. www.indiandentalacademy.com
  64. 64. Film Position & Enlargement  Other significant change from original technique is adjustability of film position.  The original cephalostat was based on the design of the anthropometric craniometer & cassettes were attached to these mechanisms. www.indiandentalacademy.com
  65. 65.  The disadvantage of this very efficient mechanical design is that it makes cassette position and resultant enlargement dependent on head size.  Evaluation of serial changes by direct superimposition is made unreliable by this variable enlargement. www.indiandentalacademy.com
  66. 66.  The relative immunity of angular measurements to enlargement distortions led researchers to opt for angular over linear values when possible.  Newer instruments have been developed to over come this variable enlargement by providing independent adjustments for head holding mechanisms & cassette. www.indiandentalacademy.com
  67. 67. Postero-Anterior (Frontal) Cephalometry www.indiandentalacademy.com
  68. 68. PA Cephalometry  Since the introduction of a standardized method for obtaining skull radiographs, cephalometrics has become one of the major diagnostic tools in orthodontics.  The posterior anterior cephalogram contains diagnostic information not readily available from other sources. www.indiandentalacademy.com
  69. 69.  PA Ceph allows to evaluate the width and angulation of the dental arches to their osseous bases in the transverse plane.  Helps evaluate the width and transverse positions of the maxilla and mandible,  To assess nasal cavity width; and analyze vertical and/or transverse facial asymmetries. www.indiandentalacademy.com
  70. 70.  A cephalostat that can be rotated 90° is used, so that the central beam passes the skull in a postero anterior direction and bisects the transmeatal axis at 90o.  Maintaining the identical horizontal orientation from lateral to the PA projection is critical when comparative measurements are made. (Moyers et al). www.indiandentalacademy.com
  71. 71.  In using NHP for PA ceph, the practical problem encountered is that the patient facing the cassette makes it difficult for the patient to look in to a mirror to register NHP (Solow &Tallgren).  Space problems make it impossible to place a nose piece in front of nasion to establish support in vertical plane. www.indiandentalacademy.com
  72. 72.  As far as exposure is considered, more exposure is needed for PA cephalograms than lateral views (Enlow).  For better evaluation of patients with craniofacial anomalies that require special attention to upper face, the patient should be positioned with the tip of the nose and forehead lightly touching the cassette holder (Chierci). www.indiandentalacademy.com
  73. 73.  In cases of suspected significant mandibular displacement, the PA cephalogram should be taken with the mouth of the patient slightly open in order to differentiate between functional mandibular displacements & dentoskeletal facial asymmetry (Faber, 1985). www.indiandentalacademy.com
  74. 74. Cephalometric Landmarks  -- are readily recognizable points on a cephalometric radiograph or tracing, representing certain hard or soft tissue anatomical structures (anatomical landmarks) or intersections of lines (constructed landmarks). www.indiandentalacademy.com
  75. 75. Requirements  Should be easily seen on the roentgenogram,  Be uniform in out line, and easily reproducible.  Should have significant relationship to the vectors of growth.  Should permit valid quantitative measurements of lines and angles projected from them.  Measurements should be amenable to statistical analyses. www.indiandentalacademy.com
  76. 76.  Garn -- there are no „fixed points‟ in the skull of living person. Depends on age, sex, maturation rate, ethnic background, and other factors.  Landmarks show a range of normal variation about mean. The orthodontist to determine whether facial dimensions and relationship fall with in the range of normal variation or not. www.indiandentalacademy.com
  77. 77. Landmarks in Lat.Ceph Hard tissue landmarks  A-point (Point A, Subspinale, SS) : the deepest (most posterior) midline point on the curvature between the ANS and prosthion.  Anterior nasal spine (ANS): the tip of the bony anterior nasal spine at the inferior margin of the piriform aperture in the midsagittal plane. www.indiandentalacademy.com
  78. 78. www.indiandentalacademy.com
  79. 79.  Articulare (Ar) : constructed point representing the intersection of three radiographic images: the inferior surface of the cranial base and the posterior out line of the mandibular condyles  B-point (Point B, Supramentale, sm): the deepest (most posterior) midline point on the bony curvature of the anterior mandible, between infradenale and pogonion. www.indiandentalacademy.com
  80. 80.  Basion (Ba): the most anterior inferior point on the margin of the foramen magnum in the midsagittal plane.  Bolton (Bo) : the highest points on the outlines of the retrocondylar fossae on the occipital bone, approximating the centre of the foramen magnum. www.indiandentalacademy.com
  81. 81. www.indiandentalacademy.com
  82. 82.  Clinoidale (Cl) : most superior point on the contour of anterior clinoid -- Usu unilateral.  Condylion (Co) : the most superior point on the head of the mandibular condyle  Glabella (G): the most prominent point of the anterior contour of the frontal bone in the midsagittal plane. www.indiandentalacademy.com
  83. 83. www.indiandentalacademy.com
  84. 84.  Gnathion (Gn) : the most anterior inferior point on the bony chin in the midsagittal plane.  Gonion (Go): the most posterior inferior point on the outline of the angle of the mandible.  Incisior inferius (Ii) : the incisal tip of the most labially placed mandibular incisor.  Incisior superius (Is) : maxillary incisor. www.indiandentalacademy.com
  85. 85. www.indiandentalacademy.com
  86. 86.  Infradentale (Id) : the most superior anterior point on the mandibular alveolar process between the central incisors.  Key Ridge (KR) : the lowermost point on the contour of the shadow of the ant wall of infratemporal fossa. www.indiandentalacademy.com
  87. 87. www.indiandentalacademy.com
  88. 88.  Menton (Me) : the most inferior point of the mandibular symphysis in the midsagittal plane.  Nasion (N,Na) : the intersection of the internasal and frontonasal sutures in the midsagittal plane  Opisthion (Op) : the most posterior inferior point on the margin of the foramen magnum in the midsagittal plane www.indiandentalacademy.com
  89. 89.  Orbitale (Or) : the lowest point on the inferior orbital margin  Pogonion (pog, P, Pg) : the most anterior point on the contour of the bony chin in the midsagittal plane  Porion (Po): the most superior point on the outline of the external auditory meatus (anatomic). The superior most point of the ear rods (machine porion) sometimes is used. www.indiandentalacademy.com
  90. 90. www.indiandentalacademy.com
  91. 91.  Posterior nasal spine (PNS) : the most posterior point on the bony hard palate in the midsagittal plane, the meeting point between inferior & superior surfaces of the hard palate at its posterior aspect.  Prosthion (Pr, Supradentale) : the most inferior anterior point on the maxillary alveolar process between the central incisors. www.indiandentalacademy.com
  92. 92.  Pterygomaxillary fissure (PTM,) : bilateral inverted tear drop shaped radiolucency whose anterior border represents the posterior surfaces of the tuberosities of the maxilla.  Sella (S) : the geometric centre of the pituitary fossa (sella turcica), determined by inspection – a constructed point in the midsagittal plane. www.indiandentalacademy.com
  93. 93. www.indiandentalacademy.com
  94. 94. Soft Tissue Landmarks  Cervical point (C) : the innermost point between the submental area and the neck in the midsagittal plane. Located at the intersection of lines drawn tangent to the neck and submental areas. www.indiandentalacademy.com
  95. 95.  Inferior labial sulcus (Ils) : point of greatest concavity on the contour of the lower lip between the labrale inferius and menton in the midsagittal plane.  Labrale inferior (Li) : point denoting the vermillion border of the lower lip in the midsagittal plane.  Labrale superior (Ls) : point denoting the vermillion border of the upper lip in the midsagittal plane. www.indiandentalacademy.com
  96. 96. www.indiandentalacademy.com
  97. 97.  Pronasale (Pn) : most prominent point of the tip of the nose, in the midsagittal plane.  Soft tissue glabella (G’) : most prominent point of soft tissue drape of the fore head in the midsagittal plane.  Soft tissue menton (Me’) : most inferior point of the soft tissue chin in the midsagittal plane. www.indiandentalacademy.com
  98. 98.  Soft tissue nasion (N’, Na’) : deepest point of the concavity between the forehead and the soft tissue contour of the nose in the midsagittal plane.  Soft tissue pogonion (Pg’, Pog’) : most prominent point on the soft tissue contour of the chin in the midsagittal plane. www.indiandentalacademy.com
  99. 99. www.indiandentalacademy.com
  100. 100.  Stomion (St) : most anterior point of contact between the upper and lower lip in the midsagittal plane. When the lips are apart at rest, a superior and an inferior stomion point can be distinguished.  Stomion inferius (Sti) : highest midline point of the lower lip.  Stomin superius (Sts) : lowest midline point of the upper lip www.indiandentalacademy.com
  101. 101.  Subnasale (Sn) : point in the midsagittal plane where the base of the columella of the nose meets the upper lip.  Superior labial sulcus (Sls) : point of greatest concavity on the contour of the upper lip between subnasale and labrale superius in the midsagittal plane.  Trichion (Tr) : demarcation point of the hair line in the midline of the forehead. www.indiandentalacademy.com
  102. 102. www.indiandentalacademy.com
  103. 103. PA Ceph Bilateral Skeletal Landmarks  Greater Wing Superior Orbit (GWSO) - the intersection of the superior border of the greater wing of the sphenoid bone and lateral orbital margin.  Greater Wing Inferior Orbit (GWI0) - the intersection of the inferior border of the greater wing of the sphenoid bone and the lateral orbital margin. www.indiandentalacademy.com
  104. 104.  Lesser Wing Orbit (LWO) - the intersection of the superior border of the lesser wing of the sphenoid bone and medial aspect of the orbital margin.  Orbitale (O) - the midpoint of the inferior orbital margin.  Lateral Orbit (LO) - the midpoint of the lateral orbital margin. www.indiandentalacademy.com
  105. 105.  Medial Orbit (MO) - the midpoint of the medial orbital margin.  Superior Orbit (SO) - the midpoint of the superior orbital margin.  Zygomatic Frontal (ZF) - the intersection of the zygomaticofrontal suture and the lateral orbital margin. www.indiandentalacademy.com
  106. 106. S o So OO M o Lo Zf www.indiandentalacademy.com
  107. 107.  Zygomatic (Z) - the most lateral aspect of the zygomatic arch.  Foramen Rotundum (FR) - the center of foramen rotundum.  Condyle Superior (CS) - the most superior aspect of the condyle.  Center Condyle (CC) - the center of the condylar head of the condyle. www.indiandentalacademy.com
  108. 108.  Mastoid Process (MP) - the most inferior point on the mastoid process.  Malar (M) - the deepest point on the curvature of the malar process of the maxilla.  Nasal Cavity (NC) - the most lateral point on the nasal cavity. www.indiandentalacademy.com
  109. 109.  Mandible/Occiput (MBO) - the intersection of the mandibular ramus and the base of the occiput.  Gonion (G) - the midpoint on the curvature at the angle of the mandible (gonion).  Antegonial (AG) - the deepest point on the curvature of the antegonial notch. www.indiandentalacademy.com
  110. 110. Cs Cc Z Mp G Ag www.indiandentalacademy.com
  111. 111. Midline Skeletal Landmarks  Crista Galli (CG) - the geometric center of the crista galli.  Sella Turcica (ST) - the most inferior point on the floor of sella turcica. www.indiandentalacademy.com
  112. 112.  Nasal Septum (NSM) - the approximated midpoint on the nasal septum between crista galli and the anterior nasal spine.  Anterior Nasal Spine (ANS) - the center of the intersection of the nasal septum and the palate.  Incisor Point (IPU) - the crest of the alveolus between the maxillary central incisors. www.indiandentalacademy.com
  113. 113.  Incisor Point (IPL) - the crest of the alveolus between the mandibular central incisors.  Genial Tubercles (GT) - the center of the genial tubercles of the mandible.  Menton (ME) - the midpoint on the inferior border of the mental protuberance. www.indiandentalacademy.com
  114. 114. Bilateral Dental Landmarks  Maxillary Cuspid (MX3) - the incisal tip of the maxillary cuspid.  Maxillary Molar (MX6) - the midpoint on the buccal surface of the maxillary first molar. www.indiandentalacademy.com
  115. 115.  Mandibular Cuspid (MD3) - the incisal tip of the mandibular cuspid.  Mandibular Molar (MD6) - the midpoint on the buccal surface of the mandibular first molar. www.indiandentalacademy.com
  116. 116. www.indiandentalacademy.com
  117. 117. Identification And Reproducibility  Cephalometric measurements are subject to errors that may be caused by radiographic projection errors with in the measuring system & errors in landmark identification. www.indiandentalacademy.com
  118. 118.  Identification errors are considered as the major source of cephalometric error. Factors involved are:  Density & sharpness of the image.  Anatomic complexity & superimposition of hard and soft tissues.  Observer‟s experience. www.indiandentalacademy.com
  119. 119.  To determine the reproducibility of some commonly used 15 landmarks. A Meta analysis was carried out by B. Tipkova, P. Major, N. Prasad & B. Hebbe in 1997.  The 15 landmarks were N, S,Or, Ba, P, ANS, PNA, Pt. A, Ptm, Go, Co, Ar, Pog, Me, Pt.B. www.indiandentalacademy.com
  120. 120.  It was concluded that some landmarks are more reproducible in a horizontal direction and others in a vertical direction.  B, A, Ptm,Go, & S, exhibited acceptable levels of accuracy along the horizontal axis.  A, S, Ptm exhibited acceptable levels of along the vertical axis as well. www.indiandentalacademy.com
  121. 121. Identification error in PA (Frontal) Ceph  Paul W. Major, Donald E. Johnson and Karen L. Hesse conducted a study which was designed to quantify the intraexaminer and interexaminer reliability of 52 commonly used posterior anterior cephalometric landmarks. www.indiandentalacademy.com
  122. 122.  The horizontal and vertical identification errors were determined for a sample of 33 skulls and 25 patients.  Interexaminer landmark identification error was significantly larger than intraexaminer error for many landmarks. www.indiandentalacademy.com
  123. 123.  Baumrind and Frantz pointed out that there are 2 classes of errors associated with cephalometrics. The first is “projection” errors due to geometry of the radiographic setup.  The second error termed “errors of identification,” arise due to uncertainty involved in locating specific anatomic landmarks on the radiograph. www.indiandentalacademy.com
  124. 124.  Landmarks on a sharp curve or at the intersection of curves are generally identified easily than points located on flat or broad curves.  Points located in areas of high contrast are easier to identify than points located in areas of low contrast.  Superimposition of other structures, reduces the ease of identification. www.indiandentalacademy.com
  125. 125. Conclusion  Broadbent‟s gave us a three dimensional analysis, but orthodontics has remained preoccupied with the lateral view. The lateral view is easy to work with and the patient is also much more recognizable than in the frontal (P-A) view, especially with soft tissue enhancement. www.indiandentalacademy.com
  126. 126.  Clinical orthodontics is yet to fully utilize Broadbent‟s contribution.  We treat in three dimensions and the width dimension that are visualized on the frontal view are crucial in many cases.  In these days of increasing awareness of the contribution of muscular and respiratory function, we can no more afford to ignore it. www.indiandentalacademy.com
  127. 127. Broadbent www.indiandentalacademy.com

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