Cephalometric radiography involves precise positioning of the head to obtain radiographs called cephalograms. Cephalograms allow direct bony measurements and are used for studying craniofacial growth, diagnosing deformities, treatment planning, and evaluating relapse. Key landmarks and structures are identified on cephalograms and tracings are made following specific steps. The WITS appraisal uses a single measurement between points A and B projected onto the occlusal plane to assess anteroposterior jaw disharmony, providing a diagnostic tool when other analyses like ANB may be unreliable.

1. ROENTGENOLOGY IN ORTHODONTICS
-WITS
Done by : Dr.sakhaa Garfan MSD

2. Cephalometric Radiography
 Cephalometric radiography is a technique that
depends on precise placement of the individual in a
cephalostat so that the head can be precisely
oriented.
 The radiograph that obtained is called a
cephalogram


3.  This technique combines the advantages of both
craniometry and anthropometry in that direct bony
measurements as seen on the radiograph .
 the disadvantage is that it produces a two
dimensional representation of a three-dimensional
structure making it impossible to make all the
measurements.

4. USES OF CEPHALOMETRICS
 Study of craniofacial growth
 Diagnosis of craniofacial deformity
 Treatment planning
 Evaluation of treated cases
 Study of relapse in orthodontics

5. types of cephalogram
Frontal Latral

6. POINTS AND LANDMARKS
 Cephalometric landmarks and points should have the
following attributes:
 1. Landmarks should be easily seen on the radiograph,
they should be uniform in outline, and should be easily
reproducible.
 2. Lines and planes should have significant relationship
to the vectors of growth of specific areas of the skull.
 3. Landmark should permit valid quantitative and
qualitative measurements of lines and angles projected
from them.
 4. Measurements should be amenable to statistical
analyses.
 5. Cephalometric analysis preferably should not require
extensive specialized training on the part of clinical

7. ANATOMIC STRUCTURES IN THE
CEPHALOGRAM
 1- Sphenoid bone,
 2- Zygomatic bone

8.  3-Maxilla,
 4-Mandible,

9. POINTS AND LANDMARKS-DESCRIBED IN
THE LATERAL PROJECTION (Fig. 9.9)

11.  Nasion (Na) (Fig. 9.10)
 The frontonasal suture at its
most superior point on the
curve at the bridge of the
nose.
 Anterior Nasal Spine
(ANS) (Fig. 9.11) The most
anterior point on the maxilla at
the level of the palate.
 Superior Prosthion (SPr or
PR) (Fig. 9.12) Also termed
supradentale. The most
anterior inferior point on the
maxillary alveolar process,
usually found near the
cementoenamel junction of

12.  Subspinale ("A" Point) (Fig. 9.13) The most posterior
point on the curve between ANS and PR (SPr)."A"
point is usually found 2mm anterior to the apices of
the maxillary central incisor root.

13.  Intradentale (Id) (Fig. 9.16)The
most anterosuperior point on
the mandibular alveolar
process usually found near the
cernentoenamel junction of the
mand ibular central incisor.
Also termed inferior prosthion.
 Supramentale ("8" point) (Fig.
9.17)The most posterior point
of the bony curvature of the
mandible

14.  Pogonion (Pog) (Fig. 9.18)
 Pogonion is the most anterior
point on the contour of the chin.
 Menton (Me) (Fig. 9.19)
Menton is the lowest point on the
symphyseal outline of the chin.
 Gnathion (Gn) (Fig. 9.20)The
most anteroinferior point on the
lateral shadow of the chin.

15.  Basion (Ba) (Fig. 9. 21)the most inferoposterior point in
the sagittal plane on the anterior rim of the foramen
magnum-the tip of the posterior cranial base.
 Posterior Nasal Spine (PNS) (Fig. 9.22) The most
posterior point on the bony hard plate in the sagittal
plane: usually the meeting point of the inferior and
superior surfaces of the hard plate.

16.  Sella(S) (Fig. 9.23) The center of the hypophyseal
fossa (sella turcica). It is selected by the eye, since
that procedure has been shown to be as reliable as
a constructed center.

17. BILATERAL LANDMARKS
 Orbitale (Or) (Fig. 9.24)defined as the lowest point of
the bony orbit.
 Gonion (Go) (Fig. 9.25) is the most posteroinferior
point at the angle of the mandible.

18.  Condylion (Co) (Fig. 9.26) Condylion is the most
posterosuperior point on the condyle of the mandible.
 Articulare (Ar) (Fig. 9.27) The intersection of the three
radiographic shadows: the inferior surface of the
craniaIbase and the posterior surfaces of the necks of the
condyles .

19. Pterygomaxillary Fissure (Ptm) (Fig. 9.28)A bilateral
teardrop-shaped area of radiolucency
Porion (Po) (Fig. 9.29) The "top" of the external
auditory meatus.

20. COMMONLY USED LINES AND PLANES
DESCRIBED IN THE LATERAL PROJECTION
 1-Frankfort Horizontal Plane(Fig. 9. 31, yellow line).2-S-N
Line represents the anterior cranial base(Fig. 9.31, red
line).3-Bolton's Plane (Fig. 9.31, pink line).4-Palatal
Plane (Fig. 9.31, sky blue line)5-Occlusal Plane also
known as the functional occlusal plane. (Fig. 9.31,
orange line).6-Mandibular Plane

21. TRACING TECHNIQUE
 should begin with a general inspection of the
cephalogram and then locate and identify standard
landmarks.
 Step 1:Draw at least two plus shaped crosses on the
top right and left corners of the radiograph,used to
orient the tracing over the radiograph.

22.  Step 2 Trace the soft tissue profile, external cranium,
and the cervical vertebrae.
 Step 3 These are followed by the tracing of the
cranial base, internal border of cranium, frontal
sinus, and ear rods

23.  Step 4 Maxilla and related structures including the
key ridges and pterygomaxillary fissures are then
traced. The nasal floor is also traced along with the
anterior and posterior nasal spines. The first molar
and the most anteriorly placed maxillary incisor
(including its root) are also traced.

24.  Step 5 Finally the mandible, including the symphysis,
the lower border of the mandible, the condyles and
the coronoid processes is traced. The first molars
and the most anteriorly placed incisor tooth including
its root are to be traced. The mandibular canal may
be traced and is at times used for superposi tioning
serial radiographs.

25. WITS
 THE WITS APPRAISAL OF JAW DISHARMONY
 The "Wits" appraisal of jaw disharmony employes
just one measurement and is intended as a
diagnostic aid whereby the severity or degree of
anteroposterior jaw disharmony can be measured on
a lateral cephalometric head film.
 It is to be used as an adjuvant along with other
analysis, mainly to reconfirm their results.

26.  The ANB angle is the most commonly used reading
for the appraisal of the horizontal disharmony of the
face.
 The ANB angle in normal occlusions is generally 2°.
 Angles greater than this indicate tendencies toward
Class Il jaw disharrnonies: smaller angles (extending
to negative readings) reflect Class III anteroposterior
jaw discrepancies.

27.  The SNA reading merely shows whether the face
protrudes or retrudes below the skull.

28.  The Wits appraisal is useful in identifying cases in
which ANB reading does not accurately reflect the
extent of underlying anteroposterior jaw dysplasia.
 Used in cases where ANB angle is considered not so
reliable due to factors such as position of nasion &
rotation of jaws

29.  Clockwise or counterclockwise rotation of the S-N
line (due to nasion or sella turcica being positioned
relatively superiorly or inferiorly to each other) either
increases or decreases the SNA reading.

30.  Similarly, the rotational effect of the jaws relative to
the cranial reference plane would also affect the
ANB angle reading directly.
 Reliability of ANB angle is suspected incases where
the mandibular plane angle (Go-Gn to S-N)reading is
considerably higher or lower than the mean of 32° ±
5°,

31.  The Wits appraisal entails drawing perpendiculars on
a lateral cephalometric head film tracing from points
A and point B onto the occlusal plane (which is
drawn through the region of maximum cuspal
interdigitation).
 The points of contact on the occlusal plane from
points A and Bare labeled AO and BO respectively
(Fig. 9.35A).

32.  In skeletal Class IIjaw dysplasias (Fig. 9.35B), point
BO would be located well behind point AO (A
positive reading)

33.  whereas in skeletal Class III jaw disharmonies (Fig.
9.35C) the "Wits" reading would be negative with
point BO being in front of point AO. The more the
"Wits" readings deviate from 1 mm in males and 0
mm in females, the greater the horizontal jaw
disharmony.

34. REFERENCE
 Textbook of orthodontics by Gurkeerat Singh

35. Thank you