Origin: ‘Cephalo’ means head and ‘Metric’ is
Discovery of X-rays measurement of the head
from shadows of bony and soft tissue
landmarks on the roentgenographic image ,
known as the Roentgenographic cephalometry.
“The scientific measurement of the bones of the cranium
and face, utilizing a fixed, reproducible position for lateral
radiographic exposure of skull and facial bones” -- Moyers
“ A scientific study of the measurements of the head with
relation to specific reference points; used for evaluation of
facial growth and development, including soft tissue
profile” -- Grabers
5. GOALS OF CEPHALOMETRICS
To evaluate the relationships, both horizontally and
vertically, of the five major functional components of
The cranium and the cranial base
The skeletal maxilla
The skeletal mandible
The maxillary dentition and the alveolar process
The mandibular dentition and the alveolar process
7. Requirement of Cephalometric
It should be easily seen in radiograph.
It should be uniform in outline and should be
The landmarks should permit valid quantitative
measurements of lines and angles projected
8. TYPES OF CEPHALOMETRIC
Two types of Cephalometric landmarks are :
1. ANATOMICAL LANDMARKS –These landmarks represent
actual anatomic structures of the skull.
1. DERIVED LANDMARKS – These are the landmarks that have
been obtained secondarily from anatomic structures in a
9. BASED ON TISSUE :
Landmarks can also be classified into :-
1.HARD TISSUE LANDMARKS
2.SOFT TISSUE LANDMARKS
11. Hard tissue landmarks
Some of the important hard tissue landmarks are:-
NASION : The most anterior point midway between the frontal
and nasal bones on the fronto-nasal suture.
ORBITALE: The lowest point on the inferior bony margin of the
PORION: The highest bony point on the upper margin of
external auditory meatus.
SELLA: The point represented the midpoint of the pituitary fossa
or sella turcica.It is a constructed point in the mid sagittal plane.
POINT A : It is the deepest point in the midline between the
anterior nasal spine and alveolar crest between the two central
POINT B : It is the deepest point in the midline between the
alveolar crest of mandible and the mental process.
12. BASION : It is the median point of anterior margin of foramen
BOLTON POINT : The highest point at the post condylar notch of
the occipital bone.
ANTERIOR NASAL SPINE : It is the anterior tip of the sharp bony
process of the maxilla in the midline of the lower margin of
anterior nasal opening.
GONION : It is a constructed point at the junction of the ramal
plane and the mandibular plane.
POGONION : It is the most anterior point of the bony chin in the
MENTON : It is the most inferior midline point on the
GNATHION : It is the most antero-inferior point on the
symphysis of the chin .
13. ARTICULARE : It is a point at the junction of the posterior borde of
ramus and the inferior border of the basilar part of the occipital
CONDYLION : The most superior point on the head of the condyle.
PROSTHION : The lowest and most anterior point on the alveolar
bone in the midline , between the upper central incisors. It is also
called Supradentale .
POSTERIOR NASAL SPINE : The intersection of a continuation of the
anterior wall of the pterygo-palatine fossa and the floor of the
nose, marking the distal limit of the maxilla.
GLABELLA : It is the most prominent point of the forehead in the
mid sagittal plane.
CHELION : It is the lateral terminus of the oral slit on the outer
corner of the mouth.
SUBNASALE : The point where the lowest border of the nose meets
the outer contour of the upper lip.
14. SOFT TISSUE LANDMARKS
Some of the important soft tissue landmarks are :-
GLABELLA : It is the most prominent point in the med-sagittal plane
NASION SOFT TISSUE : It is the deepest point in the concavity of the
soft tissue contour of the root of the nose.
PRONASALE : The most prominent point of the nose.
SUBNASALE : It is the intersection of the lower border of the nose
and the outer contour of the upper lip.
LABRALE SUPERIUS : The median point in the upper margin of the
upper membranous lip.
LABRALE INFERIUS : The median point in the lower margin of the
lower membranous lip.
15. SUPERIOR LABIAL SULCUS : It is the point of the greatest
concavity in the midline of the upper lip.
STOMION SUPERIUS : It is the lowest point of the upper
STOMION INFERIUS : It is the highest point of the lower
STOMION : It is the ,midpoint between stomion superius
and stomion inferius.
POGONION SOFT TISSUE : It is the most prominent point
on the soft tissue contour of the chin.
MENTON SOFT TISSUE : It is a constructed point at the
intersection of a vertical co-ordinate from menton and
the inferior soft tissue contour of the chin.
16. CEPHALOMETRICS : LINES AND
• The lines are obtained by connecting two landmarks.
• Based on their orientation the lines or planes can be
classified into horizontal and vertical.
17. HORIZONTAL PLANES
1. S.N. PLANE : It is the
cranial line between the
centre of the sella turcica
(sella) and the anterior
point of the fronto– nasal
suture (nasion) .
• It represents the anterior
18. 2. FRANKFORT
HORIZONTAL PLANE :
This plane connects
the lowest point of the
orbit (orbitale) and the
superior point of the
19. 3.OCCLUSAL PLANE : It is
a denture plane bisecting
the posterior occlusion of
the permanent molars
and premolars ( or
deciduous molars in
mixed dentition ) and
20. 4.PALATAL PLANE : It
is a line linking the
anterior nasal spine
of the maxilla and
the posterior nasal
spine of the palatine
21. 5. MANDIBULAR PLANE :
Several mandibular planes
are used in cephalometrics ,
based on the analysis being
• The most commonly used
ones are :
a. Tangent to the lower
border of the mandible
b. A line connecting gonion
and gnathion (Steiner) .
c. A line connecting gonion
and menton (Downs) .
22. 6. BASION - NASAL PLANE : It is
a line connecting the basion
and nasion .
• It represents the cranial
23. 7. BOLTON’S PLANE : This
is a plane that connects
the Bolton’s point
posterior to the occipital
condyles and nasion.
24. VERTICAL PLANES
1. A – POG LINE : It is
a line from point A on
the maxilla to
pogonion on the
25. 2. 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 ).