Cephalometrics

Basic Cephalometrics
www.indiandentalacademy.com

CEPHALOMETRICS
Cephalometric radiography:- is the production of skull
radiographs ,which are useful in making measurements
of the cranium and oro-facial complex.
PACINI- IN 1922 DEMONSTRATED THE BASIC PROCEDURE
OF CEPHALOMETRICS.
It was in 1931, HOFRATH in GERMANY
and BROADBENT in UNITED STATES published
articles in which they had refined the technique and applied
these principles to orthodontics.www.indiandentalacademy.com

15"15"60"60"
Source PlaneSource Plane
X-ray SourceX-ray Source
Patient in Head
Positioning Device
Patient in Head
Positioning Device
Mid-saggital
Plane
Mid-saggital
Plane
Film PlaneFilm Plane
X-ray Film in
Cassette
X-ray Film in
Cassette
CephalostatCephalostat

Cephalometrics is a technique
employing oriented radiographs
for the purpose of making head
measurements.
Purpose of CephalometricsPurpose of Cephalometrics
•Study craniofacial growthStudy craniofacial growth
•DiagnosisDiagnosis
•Planning orthodontic treatmentPlanning orthodontic treatment
•Evaluation of treated casesEvaluation of treated cases

Cephalometrics is a technique
employing oriented radiographs for
the purpose of making head
measurements.
Purpose of Cephalometrics
• Study craniofacial growth
• Diagnosis
• Planning orthodontic treatment
• Evaluation of treated cases

15"15"60"60"
Source PlaneSource Plane
X-ray SourceX-ray Source
Patient in Head Positioning
Device
Patient in Head Positioning
Device
Mid-saggital PlaneMid-saggital Plane
Film PlaneFilm Plane
X-ray Film in
Cassette
X-ray Film in
Cassette
Cephalostat

Cephalostat

White Black Israeli Chinese Japanese
SNA 82 85 82 82 81
SNB 80 81 78 79 77
ANB 2 4 4 3 4
U1-NA 4 mm, 22 7 mm, 23 5 mm, 24 5 mm, 24 6 mm, 24
L1-NB 4 mm, 25 10 mm, 34 6 mm, 29 6 mm, 27 8 mm, 31
U1-L1 131 119 124 126 120
GoGn-SN 32 32 35 32 34
L1-MnPl 93 100 93 93 96
L1-FH 62 51 57 57 57
Y axis 61 63 61 61 62
from Proffit,Contemporary Orthodontics, 1992
Cephalometric Values for
Selected Groups

What Are We Trying to
Accomplish?
• Find out skeletal classification
– anteroposterior
– vertical
• Find out angulation of incisors
• Consider soft tissue
– facial profile
– airway considerations

What Are We Trying to
Accomplish? (In other words)
• Is the patient Class I, II, III skeletal?
• Does the patient have a skeletal open bite
growth pattern, or a deep bite growth
pattern, or a normal growth pattern?
• Are the maxillary/mandibular incisors
proclined, retroclined or normal?
• Is the facial profile protrusive, retrusive, or
straight; can the patient breathe normally?

USES OF CEPHALOMETRICS
1. semi-longitudinal growth studies of population.
Study of growth & development :
- Cephalograms are used for longitudinal,cross-sectional
and –
--- By superimposing two ceph.radiographs taken over a
period of time will help us in knowing the amount and
direction of growth.
2..Diagnosis of a case
3.Treatment planning.
4.Prognosis
5.It serves as a record.

6.To differentiate the facial types.
7.Study cranio-facial abnormalities.
8.Growth prediction.
9.To study facial asymmetry.
10.For studying the soft tissue morphology.
-using >RICKETS
STEINER’S
HOLDAWAY’S
BURSTONE etc.,

Limitations of cephalometrics
1. It gives a 2 dimensional view
of a three dimensional
object.
2. Reliability of
cephalometrics is not always
accurate,
as there can be errors in
identifying the landmarks or
tracing etc.

CEPHALOMETRIC LANDMARKS

CEPHALOMETRICS
• DEFINITION
• Scientific study of the measurement of the
head.
• CEPHALOMETRIC RADIOGRAPHY is
a standardized method of production of skull
radiographs,which are useful in making
measurements of the cranium and the orofacial
complex.The radiograph thus obtained is
called a cephalogram.

DISCOVERED BY-
• IN 1931,HOFRATH IN GERMANY
AND BOARDBENT IN U.S.A
• Provided a standardized cephalometric
technique using a high power x-ray
machine and a head holder called a
CEPHALOSTAT.

TYPES OF CEPHALOGRAMS
• LATERAL FRONTAL

WHY CEPHALOMETRICS?
• Aids in orthodontic diagnosis by enabling the
study of skeletal,dental and soft tissue
structures of the craniofacial region.
• Aids in establishing the facial type.
• Helps in the classification of skeletal and
dental abnormalities.
• Helps in treatment planning.

• Aids in evaluating the treatment results and
recognizing changes brought about by
treatment.
• Aids in predicting growth changes and
changes associated with surgical treatment.
• Study of relapse in orthodontics.
• Valuable aid in research work.

OBTAINING A CEPHALOGRAM
• CEPHALOMETRIC EQUIPMENT
• CEPHALOSTAT,X-RAY SOURCE & A
CASETTE HOLDER.
• Cephalostat-2 ear rods-prevent movement of
the head in the horizontal plane.
• Vertical stabilization of the head-orbital
pointer that contacts the lower border of the
left orbit.

• The upper part of the face is supported with
the help of a forehead clamp which is
positioned above the region of the nasal
bridge.
• The distance between the x-ray source and the
midsagittal plane of the patient is 5 feet.

CEPHALOMETRIC
LANDMARKS
• LANDMARK-Is a point serving as a guide
for measurement.An ideal landmark is located
reliably on the skull and behaves consistently
during growth.
• It should not be assumed that all the landmarks
are equally reliable and valid.
• The reliability,reproducibility and
dependability of a landmark is affected by-www.indiandentalacademy.com

#The quality of the cephalogram.
#The experience of the tracer.
#Confusion with other landmarks.
The cephalometric landmarks should have the
following attributes-
A) Should be easily seen on the radiograph.
B)Uniform in outline.

• C)Should be easily reproducible.
• D)Landmarks should permit valid quantitative
and qualitative measurements of lines and
angles projected from them.
• E)Measurements should be amenable to
statistical analysis.

CLASSIFICATION OF
LANDMARKS
• 1)ANATOMIC LANDMARKS
• 2)DERIVED LANDMARKS
• 3)UNILATERAL LANDMARKS
• 4)BILATERAL LANDMARKS
• 5)IMPLANTS

• ANATOMIC LANDMARKS
• They represent actual anatomic structures on
the skull e.g. ANS,Na
• DERIVED LANDMARKS
• These are obtained secondarily from anatomic
structures in a
cephalogram.e.g.Ar(Articulare),Ptm(Pterygom
axillary fissure)

• IMPLANTS
• They are artificially inserted radio opaque
markers, usually made of inert metal.
• They are ‘PRIVATE POINTS’ and their
position can vary from subject to subject.
• They are ideal for longitudinal studies on the
same subject.

UNILATERAL LANDMARKS
• NASION-The most anterior point midway
between the frontal and the nasal bones in
the frontonasal suture.

ANTERIOR NASAL SPINE/ANS
• It is the tip of the sharp bony process of the
maxilla in the midline.

PROSTHION
• The lowest and the most anterior point on
the alveolar process in the median plane
between the central incisors.

SUBSPINALE/POINT A
• It is the deepest point in the midline between
the ANS and the alveolar crest, between the
two central incisors. It is also called as
subspinale.
Pink dot-pt.Awww.indiandentalacademy.com

INFRADENTALE/(Id)
• The highest and the most anterior point in the
alveolar bone in the midline between the lower
central incisors.
Blue dot-(Id)

SUPRAMENTALE/Pt.B
• It is the deepest point in the midline
between the alveolar crest and the mental
process.
Pink dot-pt.Bwww.indiandentalacademy.com

POGONION(Pog)
• It is the most anterior point of the bony chin
in the median plane.
Red dot-(Pog)

MENTON(Me)
• It is the most inferior midline point on the
mandibular symphysis.
Yellow dot-Me

GNATHION(Gn)
• It is the most antero -inferior point on the
symphysis of the chin. It is constructed by
intersecting a line drawn perpendicular to the
line connecting menton and pogonion.
Orange dot-(Gn)

BASION(Ba)
• It is the median point on the anterior margin
of foramen magnum.

POSTERIOR NASAL
SPINE(PNS)
• The most posterior point in the bony hard
palate in the sagittal plane.
• Marks the distal limit of the maxilla.

SELLA(S)
• The point representing the midpoint of sella
tursica.

• GLABELLA:It is the most prominent point
of the forehead in the mid-saggital plane.
• SUBNASALE:The point where the lowest
border of the nose meets the outer contour of
the upper lip.
●G
●Sn

BILATERAL LANDMARKS
• 1)ORBITALE(Or)
• The lowest point on the inferior bony
margin of the orbit.

G0NION
• It is a constructed point at the junction of
ramal plane and mandibular plane.

CONDYLION/(Co)
• The most superior point on the head of
condyle.

ARTICULARE/(Ar)
• It is a point at the junction of the posterior
border of the ramus and inferior border of
the basal part of the occipital bone.
Blue dot-(Ar)

PTERYGOMAXILLARY
POINT/Ptm
• It is the intersection of the inferior border of
foramen rotundum with the posterior wall of
pterygomaxillary fissure.
• It is a bilateral tear drop shaped area of
radiolucency.

PORION/(Po)
• The highest bony point on the upper margin
of the external auditory meatus.

BOLTON POINT
• The highest point at the posterior condylar
notch of the occipital bone.
Bo

• THE KEY RIDGE-The lowest most point
on the contour of the anterior wall of the
infratemporal fossa.
• CHELION:It is the lateral terminus of the oral
slit on the outer corner of the mouth.

LINES AND PLANES IN
CEPHALOMETRY
• Cephalometrics makes use of certain lines or
planes. These lines are obtained from
connecting two landmarks.
• Based on their orientation the lines or planes
are classified into:
• Horizontal and vertical planes.

HORIZONTAL PLANES
• 1)S.N.PLANE- It is the cranial line between
the center of sella tursica and the anterior point
of the fronto nasal suture(nasion).
• It represents the anterior cranial base.

FRANKFORT HORIZONTAL
PLANE
• This plane connects the lowest point of the
orbit(orbitale)and the superior point of the
external auditary meatus(porion).

OCCLUSAL PLANE
• It is a denture plane bisecting the posterior
occlusion of the permanent molars and
premolars(or deciduous molars in mixed
dentition)and extends anteriorly.

MANDIBULAR PLANE
• Several mandbiular planes are used in
cephalometrics,based on the analysis being
done. The most commonly used ones are-
• TWEEDS-Tangent to the lower border of the
mandible.
• STEINERS-A line connecting gonion and
gnathion.
• DOWNS-A line connecting gonion and
menton. www.indiandentalacademy.com

PALATAL PLANE
• It is a line linking the anterior nasal spine of
the maxilla and the posterior nasal spine of
the palatine bone.

BASION-NASION PLANE
• Line connecting the basion and nasion.
• Represents the cranial base.

VERTICAL PLANE
• A-POG LINE: It is a line from point A on
the maxilla to pogonion on the mandible.

FACIAL PLANE
• It is a line from the anterior point of the
frontonasal suture (nasion)to the most
anterior point of the mandible(pogonion).

BOLTON’S PLANE
• This is a plane that connects the Bolton's
points posterior to the occipital condyles
and nasion.
Bo

FACIAL AXIS
• It is point from Ptm point to cephalometric
gnathion.

ESTHETIC PLANE/E PLANE
• Is a line between the most anterior point of the
soft tissue nose and the soft tissue chin.

FRONTAL CEPHALOGRAM
(P-A VIEW)
This provides an antero-posterior view
of the skull.

PLANES

The goal of lateral ceph
Analysis is to establish
the
Antero-posterior and
Vertical relationships of
the
Five major cranio-facial
units.
1.The cranium and cranial base
2.The naso-maxillary complex
3.The Mandible
4.The Maxillary dentition
5.The Mandibular dentition.

STEINERS ANALYSIS
By Cecil C. STEINER------1960 – Selected what he
considered to be the most meaningful parameters
and evolved a composite analysis,which he believed
would provide the maximum clinical information
with the least number of measurements.
Certain measurements were then selected
and the means (or )
Averages were determined on a series of
individuals with normal
Occlusions.

Steiner’s analysis is divided into 3 parts:-
1. Skeletal Analysis
2. Dental Analysis
3. Soft tissue analysis

ANGLE -SNA

ANGLE- SNB

ANB-ANGLE

MANDIBULAR PLANE

INTER- INCISAL ANGLE

Soft Tissue Analysis
‘S-LINE’ : According to Steiner the lips in a well balanced faces
Should touch a line extending from the soft tissue contour of the
Chin to the middle of the ‘S’ formed by the lower border of the
Nose.
THIS LINE IS REFERRED TO AS THE ‘S’ LINE.

THE ‘S’ LINE
STEINER’S ‘S’ LINE

‘’WE CALL OUR LANGUAGE THE MOTHER TONGUE
BECAUSE THE FATHER SELDOM GETS TO SPEAK.’’

SASSOUNI’S ANALYSIS

DOWN’S ANALYSIS
DOWN’S :-Study based on 20 Caucasian subjects ,ranged
In age from 12 to 17 years of age and were equally divided
As to sex.
All the individuals possessed clinically excellent occlusions.
-1952

DOWN –divided his analysis into 2
components----
1. The skeletal component helped in
defining the underlying
facial type .
2. The dental component is used to establish
if the dentition is
placed normally in relation to the
underlying bony structures.

Y-AXIS
(GROWTH AXIS)
Angle formed by joining
Sella-gnathion line with
The F-H plane.
Mean value- - 59degrees

DOWN’S POLYGON
The graph divided into:-
1.Skeletal pattern on the
top half of the graph
2.Denture polygon on
the lower half of the
graph.
Wigglegram:- helps us in
Visualizing the type of
malocclusion I.e, Skeletal
or dental..

WITS APPRAISAL
A.J.O-1975

Wits appraisal
Functional occlusal
plane

A functional occlusal plane is drawn through the
overlapping
Cusps of first pre-molars and first molars.
Perpendiculars are drawn to the occlusal plane
from points
A and B .
The points of contact of these perpendiculars on
the occlusal
Plane are termed AO and BO.
The distance between points AO and BO gives the
antero-
Posterior relation between the two jaws,.

TWEED’S TRIANGLE
TWEED’S DIAGNOSTIC FACIAL TRIANGLEwww.indiandentalacademy.com

TWEED- developed this analysis as an aid to:
•Anchorage preparation
•To treatment planning
•And determining the prognosis of orthodontic cases
Tweed’s analysis is based primarily on the deflection
of the mandible as measured by the Frankfurt Mandibular
plane Angle(FMA) and the posture of the lower incisor.
It is done to determine the final position the lower incisor
Should occupy at the end of the treatment.
Dr.Tweed established that prognosis could be predicted
relatively accurately based on the configuration of the
triangle

Tweeds triangle is formed by:
1. Frankfurt horizontal plane
2. The mandibular plane
3. The long axis of lower incisor.s
The three angle’s formed are:
• Frankfort-Mandibular Plane(FMA) Angle----
• FH Plane with mandibular plane.
• Lower Incisor to Mandibular plane(IMPA)Angle-----
• Long axis of lower incisor with mandibular plane.
• Frankfort Mandibular Incisor Angle (FMIA)--------
• Long axis of lower incisor with FH plane.
FMA=25degrees
IMPA=90degrees
FMIA=65degrees.www.indiandentalacademy.com

Based on the FMA angle the prognosis can be
predicted:-
1. FMA 16 to 28 degrees- prognosis good
Apprx. 60% of malocclusions have FMA between 16 to 28
2.FMA from 28 to 35 degrees prognosis fair.
Extractions necessary in majority of cases
3.FMA above 35 degrees , prognosis bad ,,extractions frequently
complicate the problem.

OTHER IMPORTANT CEPHALOMETRIC
ANALYSIS
McNamara's ANALYSIS
RAKOSI’S ANALYSIS
GRUMMON’S –FRONTAL ASYMMETRY
ANLYSIS
SCHWARZ ANALYSIS
NHP –ANALYSIS
BURSTONE’S-HARD TISSUE ANALYSIS(COGS)
BURSTONE’S –SOFTY TISSUE ANALYSIS(COGS)
HOLDAWAY’S SOFT TISSUE ANALYSIS
ARNETT-SOFT TISSUE CEPH.ANLYSIS(STCA)

McNamara's ANALYSIS

LATERAL
CEPHALOGRAM

HAND WRIST
RADIOGRAPH

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Cephalometrics

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