This document provides an overview of cephalometrics including: - Definitions of cephalometrics as the scientific measurement of the bones of the cranium and face using lateral radiographs. - The goals of cephalometrics which are to evaluate relationships between the five major facial components. - Types of cephalometric landmarks including anatomical, derived, hard tissue, and soft tissue landmarks. - Examples of important cephalometric landmarks such as nasion, orbitale, pogonion, sella, point A, and point B. - Classification of cephalometric lines and planes as horizontal or vertical including planes such as the SN plane, Frankfort horizontal, and mandibular plane.

1. PRESENTED BY –
NAME – NIHARIKA SUPRIYA
ROLL NO – 42
BDS FINAL YEAR ,RAMA
BATCH

2. CONTENTS
 INTRODUCTION
 DEFINITION
 GOALS OF CEPHALOMETRICS
 CEPHALOMETRIC LANDMARKS
 CEPHALOMETRIC LINES
 CEPHALOMETRICS PLANES
 CONCLUSION
 REFRENCE

3. INTRODUCTION
Origin: ‘Cephalo’ means head and ‘Metric’ is
measurement
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.

4. DEFINITIONS
 “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 face:
 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
-- Jacobson

6. CEPHALOMETRIC LANDMARKS
cephalometric landmarks are readily recognizable
points on a cephalometric radiograph or tracing,
representing certain hard or soft tissue anatomical
structures (anatomical landmarks) & (constructed
landmarks).

7. Requirement of Cephalometric
Landmarks
It should be easily seen in radiograph.
It should be uniform in outline and should be
reproducible.
The landmarks should permit valid quantitative
measurements of lines and angles projected
from them.

8. TYPES OF CEPHALOMETRIC
LANDMARKS
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
cephalogram.

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
orbit.
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
incisors.
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
magnum.
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
median plane.
MENTON : It is the most inferior midline point on the
mandibular symphysis.
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
bone.
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
of forehead.
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
lip.
STOMION INFERIUS : It is the highest point of the lower
lip.
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
PLANES
• 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
cranial base.

18. 2. FRANKFORT
HORIZONTAL PLANE :
This plane connects
the lowest point of the
orbit (orbitale) and the
superior point of the
external auditory
meatus.

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
extends anteriorly.

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

21. 5. MANDIBULAR PLANE :
Several mandibular planes
are used in cephalometrics ,
based on the analysis being
done.
• The most commonly used
ones are :
a. Tangent to the lower
border of the mandible
(Tweed).
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
base.

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
mandible .

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 ).

26. 3. FACIAL AXIS : A line
from Ptm point to
cephalometric gnathion .

27. 4. ESTHETIC PLANE :
It is a line between
the most anterior
point of the soft
tissue nose and soft
tissue chin.

28. REFERENCE
• Orthodontics, the art and science - SI Bhalajhi .
• Contemporary Orthodontics – William Proffit .