Cephalometric analysis involves taking x-rays of the skull from different angles and measuring anatomical landmarks and relationships to assess skeletal patterns, dental patterns, and soft tissue profiles. Various instruments and techniques were developed over time to standardize cephalometric x-rays. Key developments included the cephalostat to orient the head in the same position, and advances like digital scans and 3D modeling to capture three-dimensional anatomy. Cephalometric analysis is used for diagnosis, treatment planning, evaluating treatment outcomes, and studying craniofacial growth and relapse.

1. Cephalometric
Supervision:
prof / maher fouda
Prepared By :
ameen mohammed

2. Anthropologists devised
and used several
instruments to measure
variations in the
dimensions of the
human body.
To measure the height
and breadth of skull,
they usedaninstrument
called craniometer.

3. Simon successfully tried to orient the dental study
models to the cranium and developed an instrument
called the gnathometer (1928-34).1-3 Simon tried to
orient and relate the dentition and the jaws with the
help of dental study models to the cranium

4. • .His work was to give the orthodontist a real insight
into the orientation of the dentition to the facial
skeleton in three planes of space thereby help
modulate the treatment plan in the direction of
restoration of facial balance

5. The use of radiograph to photograph the human
skeleton on a special film is perhaps one of the most
useful applications of physics in medicine .
Hofrath, aprosthodontist in Germany and Broadbent
an American orthodontist in dependently devised
the ‘head holder’ which was used to orient the head
and face to a predetermined standardized position to
make an standardised radiograph of the skull.

7. The other factors that were also standardized included
distance between radiograph film and head. The
radiograph film was always kept on left side of face
close to the head.
The distance between
the radiograph film and
source of radiographs
was kept constant at 5 feet.

9. A conventional cephalogram is taken with the
Frankfort horizontal (FH) plane oriented parallel to
the floor.
The Frankfort horizontal plane is essentially an
anthropological landmark which has been extensively
used in craniometry. The Frankfort horizontal plane
which extends from upper margin of external auditory
meatus to lowest point on the infraorbital ridge was
essentially called as YonIhering line

11. 2D to 3D cephalometrics
The lateral cephalogram as conventionally used
is a 2D image of a 3D skull (Fig. 11.1). The
lateral cephalometric film allows left halves of
the face. Efforts were made to construct a 3D
model of face using lateral and PA
cephalograms.

14. Development of the computed tomography (CT)
scan permits evaluation of any part of the bony
tissue at any depth in all the three dimensions of
space. Later research has focused on 3D
reconstruction of face from CT scans (Figs 11.2,
11.3). Latest cone beam CT (CBCT) systems
supported with sophisticated computer software
have capabilities to generate virtual reality models
of any parts of the body including face and jaws.

16. Fig. 11.2: A modern digital cephalostat
machine combined with OPG.
A. Digital cephalostat, B. Image on screen.
Cephalostat seen in the
picture has X-ray radiation originating from
left side of face, right side
being closest to the sensor, which is in
contrast to standard film based
cephalostat

17. The cephalograms were measured for the lengths,
heights and proportions of the craniofacial and
dentoalveolar structures. Numerous angles were drawn
from bony
landmarks in skull, which were used to analyse the
orientation of jaw bones to their respective bases and
to
the skull.

18. Cephalometric analysis involves location of certain
landmarks on the cephalogram, which are used to make
measurements of either angular or linear variables.
The angular variables reflect spatial relationship of the
anatomical parts. The changes measured on the serial
cephalograms with treatment or without treatment indicate
alterations in the spatial relationship and therefore
directions and sometimes, the amount of change that has
occurred.

20. Linear measurements may be in anteroposterior or
vertical direction on a lateral cephalogram, and
intransverse and vertical direction on a PA
cephalogram.
They can be usedas absolute values to measure
dentofacial/ cranial structures in sagittal, transverse
and vertical directions.
Ratio can be calculated for certain measurements
and changes in ratio with time (growth) or treatment
would be indicative of their relative alterations

22. Cephalometric analysis is the process of evaluating
skeletal,dental and soft tissue relationship of a patient ,
to come to a diagnosis of the patients’ orthodontic
problem.
Essentially cephalometric analysis involves
evaluation of the patient’s:
1. Skeletal pattern
2. Dentition and its pattern (denture pattern)
3. Soft tissue pattern of face
4. Nasopharyngeal airway
5. Growth trend.

23. 1. Study of craniofacial growth Serial cephalogram studies
have helped in providing information regarding
• The various growth patterns.
• The formation of standards, against which other
cephalograms can be compared.
• Prediction of future growth.
• Predicting the consequences of a particular treatment plan.
2. Diagnosis of craniofacial deformity Cephalograms
help in identifying, locating and quantifying the nature of the
problem, the most important result being a differentiation
between skeletal and dental malrelationships.

24. 3. Treatment planning By helping in diagnosis and
prediction of craniofacial morphology and future
growth, cephalometries help in developing a clear
treatment plan. Even prior to starting orthodontic
treatment an orthodontist can predict the final
position of each tooth within a given patient's
craniofacia I skeleton to achieve aesthetic and more
stable results. Tthelps in distinguishing cases which
can be treated with growth modification appliances
or whieh may require orthognathic surgery in future.

25. 4. Evaluation of treated cases Serial
cephalograms permit the orthodontist to
evaluate and assess the progress of
treatment and also helps in guiding any
desired change.
5. Study of relapse in orthodontics
Cephalometries also helps in identifying
causes of orthodontie relapse and stability
of treated malocclusions.

26. Cephalometric
landmarks and points

28. Nasion (Na).
The anterior most point at The junction of the
frontonasal suture at the bridge of the nose.

29. Sella is the midpoint of sella turcica or
hypophyseal fossa or pituitary fossa

30. Cephalometric landmarks
ANSanterior nasal spine
APoint A
APMAXanterior point of maxilla
Prprosthion
PNSposterior nasal spine
ptm
PTM
PTMS
Pterygomaxillary
fissure
KRKey ridge
OrOrbitale

31. The most anterior point on the maxilla at the
level of the palate

32. The most posterior point between ANS and superior
prosthoin (SPr) , and usually found 2 mm away from
upper centrals` root apices.

33. The most anterior inferior point on the maxillary
alveolar process.

34. Posterior Nasal Spine is the intersection of
a continuation of the anterior wall of the ptery
gopalatine fossa and the floor of the nose.
According to Viken Sassouni : Most posterior
point on the contour of the bony palate.

35. Pterygomaxillary fissure is a bilateral tear drop
shaped area of radiolucency, the anterior
shadow of which represents the posterior surface
of the tuberosity of the maxilla

36. The lowest point of the bony orbit.
The most inferior point on the lower border of
the left orbit. Graber

38. The most anterior superior point on
the mandibular alveolar process.

39. The incisal tip of the most anterior mandibular
incisor.

40. The incisal tip of the most anterior maxillary
incisor.

41. The most posterior point of the bony curvature of
the mandible , below the inferior prosthion and
above the Pogonion.

42. The most anterior point on the contour of the
chin.

43. The most anterior inferior point in the lateral
shadow of the chin .

44. The most inferior point on the chin .

45. The most posterior inferior point at the angle of
the mandible .

46. Articulare is the point of intersection the dorsal
contours of the processus articularis
mandibulare and os tempoarle.

47.  The most posterior superior point on the condyl
of the mandible

48. Cephalometric
Landmarks
Related to Dentition

49. Incision superius Incisalis is the incisal edge
of the maxillary central incisor.
According to Robert E Moyers
Incision superius incisalis is the incisal tip of the
most anterior maxillary central incisor.

50. Incision superius apicalis is the root apex of the
most anterior maxillary central incisor; if this
point is needed only for defining the long axis
of the tooth, the midpoint on the bisection of the
apical root width can be used.

51. Incision inferius incisalis is the incisal edge
of the most prominent mandibular central incisor.

52. Incision inferius apicalis is the root apex of the
most anterior mandibular central incisor; if this
point
is needed only for defining the long axis of the
tooth, the midpoint on the bisection of the apical
root width can be used.

53. Anterior point of occlusion for the occlusal plane–
A constructed point, the midpoint of the incisor
overbite in occlusion.

54. Posterior point of occlusion for the occlusal
plane—the most distal point of contact
between the most posterior molars in occlusion
(Rakosi).

55. Maxillary central incisor is the most labial
point on the crown of the maxillary central
incisor.

56. Maxillary first molar is the tip of the
mesiobuccal cusp of the maxillary first permanent
molar.

57. Mandibular central incisor is the most labial
point on the crown of the mandibular central
incisor.

58. Mandibular first molar is the tip of the
mesiobuccal cusp of the mandibular first
permanent molar.

59. mi is the mesial contact of the lower molar
projected normal to the plane of occlusion.

60. ms is the mesial contact of the upper molar
projected normal to the plane of occlusion.

61. Soft Tissue
Cephalometric
Landmarks

64. Soft tissue glabella is the most prominent or
anterior point in the mid sagittal plane of the
forehead at the level of the superior orbital
ridges.

65. Soft tissue nasion is the concave or retruded
point in the tissue overlying the area of the
frontonasal suture.

66. Nasal crown is a point along the bridge of the
nose halfway between soft tissue nasion (n) and
pronasale (Pn).

67. Pronasale is the most prominent or anterior
point of the nose.

68. The point “T” is the midline point on the nasal tip
taken at the level of the dome projecting points of
the lower lateral cartilage.

69. Subnasale is the point at which the nasal septum
between the nostrils merges with the upper
cutaneous tip in the midsagittal plane.

70. Soft tissue subspinale is the point of greatest
concavity in the midline of the upper lip between
subnasale (Sn) and labrale superius (Ls).

71. Labrale superius is the most anterior point
on the margin of the upper membranous lip.

72. Stomion is the median point of the oral
embrassure when the lips are closed.

73. Labrale inferius is the most anterior point
on the lower margin of the lower membrane lip.

74. Soft tissue point B or Soft tissue submentale
is the point of greatest concavity in the midline of
the lip between labrale inferius (Li) and soft
tissue pogonion
(Pog’ or Pogs).

75. Soft tissue pogonion is the most prominent
or anterior point on the soft tissue chin in the
midsagittal plane.

76. Soft tissue gnathion is the midpoint between
the most anterior and inferior points of the soft
tissue chin in the midsagittal plane.

77. Reference planes are classified into the
following two groups:
1. Horizontal cephalometric reference planes
2. Vertical cephalometric reference planes.

78. Horizontal cephalometric planes are
listed below:
 S-N Plane
 "f • Se-N Plane
 F-H Plane
 Occlusal Plane
 Palatal Plane
 Mandibular Plane

79. S-N Plane
• It is the plane formed by the line connecting
Sella turcica (midpoint of hypophyseal fossa)
and the Nasion (anterior point of frontonasal
suture).
Significance:
It represents the
anteroposterior
extent of anterior
cranial base.

80. F-H Plane
Frankfort-Horizontal plane is the plane that
connects the lowest point of the orbit (orbitale) to
the superior point of the external auditory
meatus (Porion).
Significance: It is
horizontal
cephalometric
reference plane
used to assess
horizontal growth
during the analysis.

81. Occlusal plane is formed by a line connecting
anterior point of occlusion (APOcc) to the
posterior point of occlusion (PPOcc).
Significance: It has
significant role in the
assessment of
horizontal growth

82. Palatal plane is formed by the line joining
the point anterior nasal spine (ANS) to the
posterior nasal spine (PNS).
Significance: Growth
pattern assessment.

83. It is the plane that connects the point Me
(Menton) to the point Go (Gonion).
Significance:
Growth pattern
assessment.

84. Vertical cephalometric planes include the
following:
 A-Pogline
 Facial plane
 Facial axis
 E-plane
 S-Ar plane
 Ar-Go plane.

85. It is a line from point A on the maxilla to pogonion
on the mandible.

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

87. A line from Ptm point to cephalometric
gnathion,

88. E-plane is also called esthetic plane and it is a
line between the most anterior point of the soft
tissue nose and chin.

89. It is the plane between the sella point (center
of sella turcica) and the Ar (articulare) point.
Significance: This plane represents the lateral
extent of cranial base.

90. Ar-Go plane is formed by the line connecting
from articulare (Ar) to the Gonion (Go).
Significance: This plane is important in the
determination of length of ramus.

91. 1. Down’s Analysis (1948)
2. 2. Steiner Analysis (1953)
3. 3. Tweed’s Analysis (1954)
4. 4. Sassouni Analysis (1955)
5. 5. Harvold Analysis (1974)
6. 6. Wits Analysis (1975)
7. 7. Ricketts Analysis (1979)
8. 8. McNamara Analysis (1983)
9. 9. Counterpart Analysis
10. 10.Template Analysis
11. 11.Jaraback Analysis (1972)

92. Downs’analysis
Downs felt that there are four types of faces
as viewed on lateral profile:
• Retrognathic with recessive chin
• Mesognathic with straight profile normal
chin
• Prognathic, where chin is prominent
• Prognathism when mandible is large.
Basis of Downs’ analysis
Downs considered sagittal position of the
‘chin’ of greater importance in determining the
four basic facial types

93. 1. Facial plane. A line drawn from nasion through
pogonion
2. Mandibular plane. It is drawn tangent to the Gonion
and the lowest point of the symphysis.
3. Occlusal plane. It is drawn by bisecting the overlapping
cusps of first molars and the incisal overbite. In cases in
which the incisors are grossly malposed, Downs
recommended drawing the occlusal plane through
overlapping cusps of the premolars and the molars.
4. Y-axis. It is formed by drawing a line from sella turcica
to gnathion.
5. FH plane. It is drawn using superior border of machine
porion and orbitale.

95. 1-Facial angle. It is measured as posterior inferior angle at the
intersection of facial plane with Frankfort horizontal plane
essentially indicates the degree of recession or protrusion of
the mandible in relation to upper face at the point where FHP is
related to facial plane. Increase in facial angle is suggestive of
chin protrusion

96. 2. Angle of convexity.
This angle measures the degree of the maxillary
basal arch at its anterior limit relative to the facial
profile. It is suggestive mid-face sagittal positioning.
Mean 0°, range -8.5° to +10°.

97. 3. A-B plane angle.
4. A-B plane is a measure of the relation of the
anterior limit of the apical bases to each
other relative to the facial line. Mean -4.6°,
range 0° to -9°
5. .

98. Mandibular plane angle
(MPxFHP). According to Downs, mandibular plane is
tangent to the gonial angle and the lowest point of
the symphysis.Mean = 21.9°, range 17° to 28°.
High mandibular plane
angle suggests
an unfavourable
hyperdivergent
facial pattern.

99. Y-axis is formed by joining the sella-gnathion
line with the FH plane.Planes of Y-Axis
1- Sella-gnathion
2- FH plane
Mean value: The mean value of Y-axis is 59°
and its range
is 53-66°

101. 1. Cant of Occlusal Plane Cant of occlusal
plane is formed by the intersection of occlusal
plane with FH plane.

102. Inter-incisal angle is the angle formed between
the long axis of upper and lower incisors.
Mean value: The mean value of interincisal angle
is 135.4°, while the range is 130 to 150.5°.

103. Incisor occlusal plane angle is the angle
formed by the intersection between the long axis
of lower central incisor and the occlusal plane.
Mean value: The mean value of incisor occlusal
plane angle is 14.5°, while the range is 3.5 to
20°.

104. Incisor mandibular plane angle is the angle
formed by intersection of the long axis of the
lower incisor and the mandibular plane.
Mean value: Mean is 1.4°. Range is -8.5 to 7°.

105. Upper incisor to A-pog line is a linear
measurement between the incisal edge of the
maxillary central incisor and the line joining point
A to pogonion.
Mean value: The mean value is 2.7 mm and the
range is -1 to 5 mm.

106. Cecil C Steiner in the year 1930 developed this
analysis with the idea of providing maximal
clinical information with the least number of
measurements.
This analysis has three components:
1. Skeletal analysis
2. Dental analysis
3. Soft tissue analysis

108. Following are the parameters of skeletal
analysis of Steiner's analysis:
1- SNA angle
2- SNB angle
3- ANB angle
4- Mandibular plane angle
5- Occlusal plane angle

109. SNA angle is defined as anteroposterior position
of point A relative to the anterior cranial base.
Normal mean value: The normal mean value of
SNA angle is 81°.
Planes of SNA Angle
Following are the
two planes of SNA angle:
SN plane—horizontal
NA plane—vertical.

110. Significance of SNA angle: SNA angle assesses
the degree of prognathism of maxilla
Decreased SNA angle: If SNA angle is less
than normal, then it indicates that maxilla lies
more posterior in relation to the cranial base.

111. SNB angle defines the anteroposterior position
of the mandible in relation to the anterior cranial
base.
Normal mean value: The mean value of SNB
angle is 79 °.
Planes of SNB Angle
 SN plane—horizontal.
 NB plane—vertical.

112. Significance o f SNB angle: SNB angle assess the degree of
prognathism of mandible.
Decreased SNB angle: If SNB angle is less than 79°, it is then
referred as sm all SNB angle, w hich indicates retrognathism
of mandible.
Increased SNB angle: If SNB angle is greater than 79°, then it is
called as large SNB angle. Large SNB angle— indicates
prognathism of mandible

113. ANB angle is defined as the mutual relationship
of the maxillary and mandibular bases in sagittal
plane.
Planes of ANB Angle
 NA plane—vertical
 NB plane—vertical

114. Normal mean value: Mean value of ANB angle is 2°.
ANB = SNA-SNB Angle
Significance o f ANB angle: ANB is used to assess the
sagittal relationship betw een the m axillary and mandibular
bases.
Increased ANB angle:. It indicates class II skeletal tendency.
Decreased ANB angle: It indicates class III skeletal tendency

115. Mandibular plane angle gives an indication of
growth pattern of an individual.
Planes of Mandibular Plane Angle
SN plane (S-N)
Mandibular plane (Gn-Go)
Normal mean value: The average mandibular plane angle is
32°. Significance: Assessment of growth pattern.

116. Increased mandibular plane angle: Increased
mandibular plane angle indicates vertical growth pattern.
Decreased mandibular plane angle: Decreased
mandibular plane angle iiidicates horizontal growth
pattern.

117. Occlusal plane angle indicates the relation of the
occlusal plane to the cranium and face.
Planes of Occlusal Plane Angle
 SN Plane (S-N)
 Occlusal Plane

118. Variation/Deviation of Occlusal Plane Angle
Increased occlusal plane angle: Increased occlusal
plane angle indicates vertical growth pattern.
Decreased occlusal plane angle: Decreased
occlusal plane angle indicates horizontal growth
pattern.

119. The parameters used in dental analysis are
 Upper incisor to NA angle
 Upper incisor to NA (linear)
 Lower incisor to NB angle
 Lower incisor to NB (linear)
 Interincisor angle

120. It is the angle formed by the intersection of the
long axis of the upper central incisors and the line
joining nasion topoint A.
The normal angle is 22°.
.

121. This angle indicates the relative inclination of the
upper incisors.
An increased angle is seen in patients who
have proclined upper incisors as in class II
division 1 malocclusion

122. It is a linear measurement between the labial surface
of the upper central incisors and the line joining
nasion to point A.
This measurement also helps in determining the
upper incisor position. Normal value is 4 mm. It
increases in cases with proclined upper incisors.

123. This angle is formed between the NB plane and the
long axis of the lower incisors. This angle
indicates the inclination of the lower central incisor
and has a mean value of 25°.
An increased value indicates proclination of
lower incisors whereas a decreased value
indicates upright or retroclined lower incisors.

124. It is the linear distance between the labial surface of
lower central incisors and the line joining nasion to
point B.
This measurement also helps in assessing the lower
incisor inclination.
An increase in this measurement indicates
proclined lower incisors. The normal value is 4 mm.

125. This is an angle formed between the long axis
of the upperand lower central incisors. A
reduced interincisor angle

126. associated with a class II division 1 malocclusion
or a class I bimaxillary protrusion. A larger than
normal angle is seen in class II division 2
malocclusion. The mean value
is 130 to 131°.

127. Reference Lines of the Analysis
Reference lines of the Steiner's analysis are
center point of the S-shaped curve between tip of
nose and subnasale.
Reference Line of Steiner's Lip Analysis
Reference line of Steiner's lip analysis is the line
joining from center point of the S-shaped curve
between the tip of nose and subnasale to the
lower point (soft tissue pogonion)

128. Interpretation of the Analysis
Flat lips: If lips lie behind the line connecting two reference
points, they are too flat.
Prominent lips: If lips lie anterior to the line connecting
two reference points, they are too prominent.

129. The Tweed's triangle makes use of three planes
that form a diagnostic triangle called Tweed's
triangle. Following are the planes of Tweed's
triangle:
Frankfort mandibular plane angle (FMA)
Incisor mandibular plane angle (IMP A)
Frankfort mandibular incisor plane angle
(FMIA).

130. It is the angle formed by the intersection of the
Frankfort Horizontal plane (FH Plane) with the
mandibular plane (Me-Go).
Mean Value
The mean value of Frankfort mandibular plane
angle is 25°. Range is 16-35°.

131. Decreased Frankfort Mandibular Plane Angle
If the angle is less than 16" then is referred as decreased
Frankfort mandibular plane angle. It indicates horizontal growth
pattern.
Increased Frankfort Mandibular Plane Angle If the angle is greater
than 35°, then is referred as increased
Frankfort mandibular plane angle. It indicates vertical growth
pattern.

132. It is the angle formed by the intersection of
the long axis of the lower incisor with mandibular
plane (Me-Go).
Mean Value
The mean value of incisor mandibular plane
angle is 90°. Range is 85-95°.

133. Decreased Incisor Mandibular Plane Angle
If the angle is less than 85°, then is referred as
decreased incisor mandibular plane angle. It indicates
lower incisor retroclination.
Increased incisor Mandibular Plane Angle
If the angle is greater than 95° then is referred as
increased incisor mandibular plane angle. It indicates
lower incisor proclination.

134. It is the angle formed by the intersection of the long axis
of the lower incisor with the Frankfort horizontal plane
(FH Plane).
Mean Value
The mean value of Frankfort mandibular incisor plane
angle is 65°. Range is 60-75 °.

135. Decreased Frankfort Mandibular Incisor Plane Angle
If the angle is less than 60° then is referred as decreased
Frankfort mandibular incisor plane angle. It indicates
lower incisor proclination.
Increased Frankfort Mandibular Incisor Plane Angle
If the angle is greater than 75° then is referred as increased
Frankfort mandibular incisor plane angle. It indicates
lower incisor retroclination.

137. Jacobson described the Wit's (University of
Witwater- srand, South Africa) appraisal.
W it's appraisal measures the extent to which
the jaws are related to each other antero
posteriorly.

138. Method of Assessment
 The method of assessing the extent of jaw disharmony
entails drawing perpendicular on a lateral cephalo
metric lead film tracing from point A and B on the
maxilla and mandible, respectively into the occlusal
plane, which is drawn through the region of maximum
cuspal interdigitation.
 The point of contact on the occlusal plane from A and
B are labeled AO and BO, respectively.

139. Normal Occlusion
The point AO is approximately 1 mm anterior to point BO.
Skeletal Class II Jaw Dysplasias
The point BO will be located well behind point AO.
Skeletal Class III Jaw Disharmonies
The point BO will be forward of point AO.
Deviations of Wit's Appraisal
0 1 mm in male
0 Omm in female.

140. Thank you