The document discusses cephalometrics, which involves the scientific measurement and analysis of the bones of the skull and face using lateral cephalograms. It defines cephalometrics, describes the history and development of standardized cephalometric techniques, and covers various cephalometric landmarks, planes, and analyses including Downs analysis and Steiner analysis. The summary provides an overview of the key topics covered in the document related to the definition, history, types of analyses, and landmarks used in cephalometric radiographs and analyses.

1. SUBMITTED TO:-
Dr. GARIMA
Dr. PRIYANKA
DEPARTMENT OF PEDODONTICS
CEPHALOMETRICS
SUBMITTED BY:-
VIJAY VERMA
193

2. • INTRODUCTION
• DEFINITION
• TYPES OF CEPHALOGRAM
• USES OF CEPHALOGRAM
• CEPHALOMETRIC LANDMARKS
• ANATOMIC LANDMARKS
• DERIVED LANDMARKS
• SOFT TISSUE LANDMARKS
• CEPHALOMETRIC PLANES
• CEPHALOMETRIC ANALYSIS :-DOWN’S ANALYSIS
:-STEINER ANALYSIS
:-TWEED ANALYSIS
:-WITS APPRASIAL
• ERRORS IN CEPHALOMETRY
*

3. *
• ORIGIN ‘CEPHALO’ means head and ‘ METRIC’ is measurement.
• DISCOVERY OF X RAYS BY ROENTEGEN in 1895 revolutionized
dentistry .
• It provided a method of obtaining inner craniofacial measurement
with quite a bit accuracy and reproducibility.
• In 1922 paccini standardized radiographic head images by
positioning subjects against a film cassete at a distance of 2meters
from x- ray tube
• In 1931 Boardbent in U.S.A. and Hofrath in Germany
simultaneously presented a standardized cephalometric technique
USING HIGH POWERED X- RAY machiene and a head holder is called
cephalostat .
• The term cephalometric is used to describe analysis and
measurement made on cephalometric radiographs.

4. ACC. TO MOYERS
*“THE SCIENTIC MEASUREMENT OF BONES OF CRANIUM AND FACE
‘UTILIZING A FIXED ,REPRODUCIBLE POSITION FOR LATERAL
RADIOGRAPHIC EXPOSURE OF SKULL AND FACIAL BONES”.
ACC. TO GRABERS
*“A SCIENTIFIC STUDY OF MEASUREMENT OF HEAD WITH
RELATION TO SPECIFIC MEASUREMENT POINT ;USED FOR
EVALUATION OF FACIAL GROWTH AND DEVELOPMENT
,INCLUDING SOFT TISSUE PROFILE “.

5. 
* CEPHALOGRAM can be of two types:
1. Lateral cephalogram
2. Frontal cephalogram
LATERAL CEPHALOGRAM
 THIS PROVIDE S A LATERAL VIEW OF SKULL .
 It is taken with head in a standardized reproducible position at a specified distance
from x- ray.
FRONTAL CEPHALOGRAM
 This provides an antero-posterior view of skull.

6. *
IN ORTHODONTIC DIAGNOSIS AND TREATMENT PLANNING.
IN CLASSIFICATION OF SKELETAL AND DENTAL
ABNORMALITIES.
IN ESTABLISHING FACIAL TYPES.
IN EVALUATION OF TREATMENT RESULTS.
IN PREDICTING GROWTH RELATED CHANGES, AND
CHANGES ASSOCIATED WITH SURGICAL TREATMENT.
VALUABLE AID IN RESEARCH WORK INVOLVING CRANIO
DENTOFACIAL REGION

7. *CEPHALOMETRIC LANDMARKS
*CEPHALOMETRIC MAKE USE OF CERTAIN LANDMARKS OR POINTS
ON SKULL THAT ARE USED FOR QUANTITATIVE ANALYSIS AND
MEASUREMENTS.
*CEPALOMETRIC LANDMARKS CAN BE OF 2 TYPES:
*ANATOMIC LANDMARKS
REPRESENT ACTUAL ANATOMIC STRUCTURES OF SKULL
*DERIVED LANDMARKS
THESE ARE LANDMARKS THAT HAVE BEEN OBTAINED
SECONDARILY FROM ANATOMIC STRUCTURES IN CEPHALOGRAM

8. *FOLLOWING ARE SOME IMPORTANT CEPHALOMETRIC
LANDMARKS:-
*NASION: most anterior point midway between frontal and nasal bone on fronto-nasal
suture.
*ORBITALE: lowest point on inferior bony margin of orbit.
*PORION: highest bony point on upper margin of external auditory meatus.
*SELLA: point representing a midpoint of pituitary fossa or sella turcica. It is a
constructed point in mid sagittal plane.
*Point A: deepest point in midline between anterior nasal spine and alveolar crest
between two central incisors.
Also called subspinale.

9. *POINT B: deepest point in midline between alveolar crest of mandible
and mental process.
Also called supramentale.
*BASION: median point of anterior margin of foramen magnum.
*BOLTON POINT: highest point at post condylar notch of occipital bone.
*ANTERIOR NASAL SPINE: it is anterior tip of sharp bony process of
maxilla in midline of lower margin of anterior nasal opening .
*GONION: it is a constructed point at junction of ramal plane and
mandibular plane
*POGONION: it is most anterior point of bony chin in median plane.
*MENTON: it is most inferior midline point of mandibular symphysis.
*GNATHION: it is most antero-inferior point on symphysis of chin . It is
constructed by a line drawn perpendicular to line connecting menton
and pogonion .
*ARTICULARE: it is a point at junction of posterior body of ramus and
inferior boarder of basilar part of occipital bone.

10. *CONDYLION : most superior point on head of condyle.
*PROSTHION: lowest and most anterior point on alveolar bone
in midline ,between upper central incisors. It is called
supradentale .
*INFRADENTALE: highest and most anterior point on alveolar
process , in median plane between mandibular central incisor
*POSTERIOR NASAL SPINE: the intersection of a continuation of
anterior wall of pterygo-palatine fossa and floor of nose
making distal limit of maxilla.
*Glabella: it is most prominent point on forehead in mid-sagital
plane .
*CHELION: it is lateral terminus of oral slit on outer corner of
mouth .
*SUBNASALE: point where lower boarder of nose meets outer
contour of the upper lip.
*PTM POINT: it is intersection of inferior boarder of foramen
rotandum with posterior wall of pterygomaxillary fissure.

12. *SOFT TISSUE LANDMARKS
*GLABELLA : it is most prominent point in midsagittal plane of
forehead.
*NASION SOFT TISSUE: it is deepest point in concavity of soft tissue
contour of root of the nose.
*PRONASALE: the most prominent point of the nose.
*SUBNASALE: it is intersection of lower boarder of nose and outer
contour of upper lip.
*LABRALE SUPERIUS : the median point in upper margin of upper
membranous lip.
*SUPERIOR LABIAL SULCUS: it is point of greatest concavity in
midline of upper lip . It is located between subnasale and labrale
superious.
*STOMION SUPERIOUS: it is lowest point of upper lip.
*STOMION INFERIOUS: I is highest point of lower lip.

13. GLABELLA
PRONASALE
COLUMELLAPOINT
SUBNASALE
LABRALE SUPERIUS
STOMION SUPERIUS
LABRALE INFERIUS
STOMION INFERIUS
LOWER LIP VERMILION
SOFT TISSUE POGONION
SOFT TISSUE MENTON

14. SOFT TISSUE GNATHION

15. *STOMION : it is midpoint between stomion superius and
stomion inferius.
*LABRALE INFERIOUS: median point in lower margin of
lower membranous lip.
*POGONION SOFT TISSUE : it is most prominent point on
soft tissue contour of chin.
*MENTON SOFT TISSUE: it is a constructed point at the
intersection of vertical co-ordinate from menton and
inferior soft tissue contour of the chin.

16. *Antegonion (ag) - The highest point in the antegonial notch.
*Anterior nasal spine (ans)- It is the anterior tip of the sharp bony process
of the maxilla in the midline of the lower margin of anterior nasal opening.
*Condylar (cd) - It is the superior most point of the condylar head.
*Coronoid (cor)- It is the superior most point of the coronoid process.
*Incision inferior frontale (iif) - It is the midpoint between the two
mandibular central incisors at the level of the incisal edge.
*Incision superior frontale (isf) - It is the midpoint between the two
maxillary central incisors at the level of the incisal edge.
*Lateral piriform aperture (Ipa) - It is the most lateral aspect of the
piriform aperture.
*Mandibular midpoint (m)- It is a point obtained by projecting the mental
spine on the inferior mandibular border.
*Maxillary molar (um) - The lateral most point on the buccal surface of the
first permanent maxillary molar or the second deciduous maxillary molar.
• IMPORTANT POSTERO-ANTERIOR CEPHALOMETRIC
LANDMARKS

17. *Mandibular molar (1m) The lateral point on the buccal surface of
The permanent mandibular molar or the second deciduous
mandibular molar.
*Mastoid (ma) - The lowest point of the mastoid process.
*Maxillare (mx) - It is the intersection of the lateral contour of the
maxillary alveolar process and the lower border of the zygornatic
process of the maxilla.
*Medio-orbitale (mo) - The median most point of the medial orbital
margin.
*Mental foramen (mf)- It is the centre of the mental foramen.
*Point zygomatic arch (za) - The lateral most point of the centre of
the zygomatic arch.
*Top nasal septum (tns) - The highest point of the nasal septum.
*Zygomaticofrontal medial suture point in (mzmf) - Point at the
medial margin of Zygomaticofrontal suture.
*Zygomaticofrontal lateral suture point (Izmf) - Point; at the
lateral margin zygomaticofrontal suture.

19. * LINES AND PLANES IN CEPHALOMETRICS
 CEPHALOMETRICS makes use of certain lines or planes.
 These lines are made by connecting two landmarks.
 Based on orientation of the lines or planes can be classified into
horizontal and vertical planes.
HORIZONTAL PLANES:
• S.N. PLANE: It is cranial line between centre of sella tursica
(sella) and anterior point of fronto nasal suture (nasion) .it
represent anterior cranial base.
• FRANKFORT HORIZONTAL PLANE : This plane connects lowest
point of orbit (orbitale)and the superior point of external auditary
meatus (porion)
• OCCLUSAL PLANE : It is a denture plane bisecting the posterior
occlusion of permanent molars and premolars and extends
anteriorly.
• PALATAL PLANE: IT is a line linking the anterior nasal spine of
maxilla and posterior nasal spine of palatine bone.

20. *MANDIBULAR PLANE: Several mandibular planes are used in
cephalometrics based on analysis being done .
*Most commonly used ones are:
1. Tangent to lower boarder of mandible (tweed)
2. A line connecting gonion and gnathion (steiner)
3. A line connecting gonion and menton. (downs)
*BASION NASION PLANE : IT IS ALINE CONNECTING NASION AND
BASION .
*IT represent the cranial base.
*BOLTON’S PLANE : This is a plane that connects bolton point
posterior to occipital condyles and nasion

21. *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 fronto-nasal
suture (nasion) to the most anterior point of the mandible (pogonion).
*Facial axis: A line from Ptm point to cephalomerric gnathion.
*E. Plane: or the esthetic plane is a line between the most anterior
point of the soft tissue nose and soft tissue chin
*DOWNS ANALYSIS
*One ot the most frequently used cephalomet-tic analysis is the Downs
analysis. Downs had based his findings on 20 Caucasaion individuals of
12-17 years age group belonging to both sexes.Down analysis consists of
10 parameter of which five are skeletal and five are dental.
*SKELETAL PARAMETER
*Facial angle:- It is the inferior angle formed by intersection of nasion-
pogonion plane and the F.H plane
VERTICAL PLANES

22. *The average value is 87.8° while the range 82 ° - 95 ° This angle gives
us an indication of the antero-posterior positioning of the the mandible
in relation to the upper face. The magnitute of this value increases in
cases of skeletal Class III with prominent chin while it decreases in
skeletal Class II cases.
*Angle of convexity: This angle is formed by the intersection of a line
from nasion to point A and a line from point A to pogonion This angle
reveals the convexity or concavity of the skeletal profile.
*The average value is 0° while the range is between - 8.5 to 10°. A
positive angle or an increased angle suggests a prominent maxillary
denture base relative to mandible.
*A decreased angle of convexity or a negative angle is indicative of a
prognathic profile.
*A-B plane angle: This angle is formed between a line connecting point
A and point B and a line joining nasion to pogonion (facial plane)The
mean value is -4.6° while the range is -9 to 0°. This angle is indicative
of the maxillo-mandibular relationship in relation to the facial plane. It
is usually negative in value since point B is positioned behind point A,
In case of Class III malocclusions a positive angle may be found.

23. *Mandiular plane angle: The mundiulur plane angle is formed by the
intersection of the mandibular plane with the F.H plane .The mean value
is 21° while the range is 17 to 28°, An increased mandibular plane angle
is suggestive of a vertical grower with hyperdivergent facial pattern.
*Y - axis (growth axis): Tins angle is obtained by joining the sella-gnathion
line with the F.H. plane. The mean value is 59° with a range of 53° to
66°. The angle is larger in Class II facial patterns than in patients
exhibiting Class III pattern. In addition, the Y-axis indicates the growth
pattern of the individual. If the angle is greater than normal, it indicates
greater vertical growth of mandible. If the angle is smaller than normal,
it indicates greater horizontal growth of mandible.
*DANTAL PARAMETERS
*Cant of occlusal plane: the mean value is 9.3° while range is 1.5 to 14 °
*Inter incisal angle: the average reading is 135.4° while yje range os
between 130 to 150.5°
*Insisor occlusal plane angle: The average value is 14.5° The range is
between 3.5 to 20°
*Incisor mandibular plane angle: This angle is formed by intersection of
the long axis of the lower incisor and the mandibular plane

24. FACIAL ANGLE

25. ANGLE OF CONVEXITY

26. A-B PLANE ANGLE

27. MANDIBULAR PLANE ANGLE

28. CANT OF OCCLUSAL PLANEY-AXIS

29. INTER INCISAL ANGLE INCISOR OCCLUSAL PLANE ANGLE

30. INCISOR MANDIBULAR PLANE ANGLE UPPER INCISOR TO A-POG LINE

31. STEINER ANALYSIS
• SKELETAL PARAMETERS:-
SNA ANGLE
SNB ANGLE
ANB ANGLE
MANDIBULAR PLANE ANGLE OCCLUSAL
PLANE ANGLE
• DENTAL PARAMETERS:-
UPPER INCISOR TO N-A ANGLE
UPPER INCISOR TO N-A LINEAR
LOWER INCISOR TO N-B ANGLE
LOWER INCISOR TO N-B LINEAR
INTER INCISOR ANGLE
SOFT TISSUE ANALYSIS:-
S LINE

32. SNA (Maxillary position) 82.0
SNB (Mandibular position) 80
ANB (Maxillary/Mandibular relation) 2
lncisor to NA (Upper incisors to NA mm) 4mm
lncisor to NA (Upper incisors to NA degree) 22
lncisor to NB (Lower incisors to NB mm) 4mm
lncisor to NB (Lower incisors to NB degree) 25
lnter-incisal angle 131
Mandibular plane angle 32
SN to occlusal plane 14

36. *TWEED ANALYSIS
*The Tweed analysis makes use of three planes that form a
diagnostic triangle. The planes used are:
*Frankfort horizontal plane
*Mandibular plane
*Long axis of lower incisor
*The objectives of the analysis include the determination of the
position of the lower incisor and evaluation of prognosis of a
case. The angles formed by these three planes are:
*Frankfort mandlbular plane angle (FMPA)
*It is the angle formed by the intersection of the Frankfort
horizontal plane with the mandibular plane. The mean value is
25°.
*Incisor mandlbular plane angle (IMPA)
*It is the angle formed by the intersection of the long axis of the
lower incisor with the mandibular plane. It indicates the
inclination of the lower incisor. The mean value is 90°.

37. *Frankfort mandlbular Incisor angle (FMIA)
*It is the angle formed by the intersection of the long axis of the
lower incisor with the F.H.plane. The mean value is 65°.
FMA(Frankfurt plane to
mandibular plane)
16-35
FMIA (Frankfurt plane to lower
incisor angulation)
85-95
IMPA(Lower incisor to
mandibular plane)
60-75

39. WITS APPRAISAL
 The wits appraisal is a measure of the extent to which the
maxilla and the mandible are related to each other in the antero-
posterior or sagittal plane. The wits appraisal is used in cases
where the ANB angle is considered not so reliable due to factors
such as position of nasion and rotation of the jaws.
 A functional occlusal plane is dwawn through the overlapping
cusps of premolars 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
anteroposterior relation between the two jaws. In case of males
point BO is ahead of AO by 1mm, while in case of females the
points AO and BO coincide. In case of skeletal Class II tendency
BO is usually behind AO (read as a positive reading) while in
skeletal Class III pattern the point BO is located ahead of AO .

41. *COMPUTERIZED CEPHALOMETIC SYSTEMS
*Computers are now widely used in cephalometrics.
The computerized cephalometric systems allow for
quick digitising of the landmarks and generation of
various cephalometric analyses. They also make
superim-positions of serial radiographs possible.
Prior to die introduction of computerized
cephalometry, all angular and linear measurements
were calculated manually. Besides being time
consuming, it involves the possibility of human
error.

42. *The advantage of this system include:
*Easy storage and retrieval of CEPHALOMETRICS ANALYSIS
*Integration of cephalometric registration
*Combination of the cephalometric data with other patient
record including photographs
*ERRORS OF CEPHALOMETRY
*A number of possible errors may creep in during
cephnlomeiry as it involves a number of steps such as
obtaining a good radiograph, use geometric construction
and analysis and interpretion of the values obtained
without any observer bias. Although conventional
cephalometry may be associated with a number of sources
of errors,it still offers vital information for the
orthodontist in dianosis and treatment,planning.

43. *CEPHALOMETRIC SUPERIMPOSITION
*Cephalometric superimposition involves the analysis of the lateral
cephalogram of the same patient taken at different time intervals.
The main utility of such a procedure is to evaluate the patient's
growth pattern and to evaluate the changes produced by orthodontic
and surgical procedures. Cephalometric superimposition should involve
the following:
1.Changes to the overall face.
2.Changes to the maxilla and the maxillary dentition
3.Changes to the mandible and the dentition
4.The amount and the dentition of condylar growth
5.Mandibular rotations
*Broadbent triangle
*This method was described by Broadbent in 1931. The broadbent
triangle is obtained using the landmarks nasion (Na), sella (S) and
Boltons point (Bo). R point is the midpoint of the perpendicular from
the centre of sella tursica to the Bolton plane. The serial tracings are
registered on the R point keeping the Bo - Na plane parallel to each
other.

44. *Sella-Nasion line:-
*In this method the two tracings are oriented on the sella -
nasion plane using the sella as a registration point. This method
was described by American board of orthodontics in 1990.
*Baslon horizontal:-
*This method uses the basion horizontal which is constructed at
the level of anterior border of the foramen magnum parallel to
the FH plane. Basion is used as the registration point. This
method was described by Coben in 1986.
*Basion-Naslon plane:-
*This is suggested by Ricketts in 1979. In this method the tracings
are superimposed on die basion - nasion plane and point cc is
used as die registration point. The cc point is the intersection of
die basioii-nasioii plane and the facial axis.

45. *Maxillary superlmposltlons
This is done to determine the movement of the maxillary teeth
in relation to the basal part of die maxilla. The methods include:
1. Superimposition along the palatal plane using anterior nasal
spine (ANS) as the reference point.
2. Superimposition on the nasal floor and registered at the
anterior surface of the maxilla.
3. Superimposition along the palatal plane using the
pterygomaxillary fissure as the registration point.
4. Superimposition on the best fit of the internal palatal
structures. The tracings are superimposed so that the contour
of the oral part of the palate, nasal floor and the entrance of
the incisal canal form a best fit
5. Superimpose on the on the outline of infratemporal fossa and
the posterior portion of the hard palate.

46. *Mandibular superlmposltlons
*This is done to determine the movement of the mandibular
teeth in relation to the basal part of the mandible. The areas
that have been suggested for the superimpositions include:
1. Lower border of the mandible.
2. The constructed mandibular plane between menton and
gonion.
3.The anterior contour of the chin.
4.The inner contour of the cortical plates at the inferior border
of the symphysis.
5.Contours of the mandibular canal posteriorly and lower
contours of mineralised molar tooth germs.