This document discusses various extraoral and intraoral radiographic techniques used in dentistry. It describes different cephalometric projections like lateral, PA, and submentovertex views used to examine fractures and TMJ disorders. Common maxillofacial projections shown are occipitomental, posteroanterior skull, and reverse Towne's views. Intraoral techniques discussed include periapical, bitewing, and occlusal radiographs used for caries detection, implant planning, and foreign body localization. The document provides indications, positioning, and advantages of each radiographic method.

1. Extra oral Radiology
Dr. Rahma Mohammed & Dr. Omer Khairy

2. Cephalometry
 Lateral cephalometric projection
 Posteroanterior projection
 Water’s projection
 Submentovertex projection
 Reverse Towne’s projection

3. Main indications
 Fractures of the maxillofacial skeleton
 Fractures of the skull
 Investigation of the antra
 Diseases affecting the skull base and cranial vault
 TMJ disorders.

4. Main maxillofacial/skull projections
 Standard occipitomental (0° OM)
 30° occipitomental (30° OM)
 Postero-anterior of the skull (PA skull) sometimes referred to as occipitofrontal (OF)
 Postero-anterior of the jaws (PA jaws)
 Reverse Towne's
 Rotated postero-anterior (rotated PA)
 True lateral skull
 Submento-vertex (SMV)
 Transcranial
 Transpharyngeal.

5. The main clinical indications include:
 Investigation of the maxillary antra
 Detecting the following middle third facial fractures:
— LeFortI
— Le Fort II
— Le Fort III
— Zygomatic complex
— Naso-ethmoidal complex
— Orbital blow-out
 Coronoid process fractures
 Investigation of the frontal and ethmoidal
sinuses
 Investigation of the sphenoidal sinus
(projection needs to be taken with the patient’s mouth open).
Standard occipitomental (0° OM)

6. Technique and positioning
1. The patient is positioned facing the film with
the head tipped back so the radiographic baseline
is at 45° to the film, the so-called . This positioning drops the dense bones of the
base of the skull downwards and raises the facial bones so they can be seen.
2. The X-ray tube head is positioned with the central ray horizontal (0°) centered
through the occiput .

8. 30° occipitomental (30° OM)
•This projection also shows the facial skeleton, but
from a different angle from the 0° OM, enabling
certain bony displacements to be detected.
Main indications
• Detecting the following middle third facial
fractures:
— LeFortI
— Le Fort II
— Le Fort III
• Coronoid process fractures.

9. Technique and positioning
1. The patient is in exactly the same position as
for the 0° OM, i.e. the head tipped back, radiographic baseline at 45° to the film, in the
nose-chin position.
2. The X-ray tube head is aimed downwards
from above the head, with the central ray at 30° to the horizontal, centered through
the lower border of the orbit

11. Postero-anterior of the skull (PA skull)
Main indications
• Fractures of the skull vault
• Investigation of the frontal sinuses
• Conditions affecting the cranium,
particularly:
— Paget's disease
— multiple myeloma
— hyperparathyroidism
• Intracranial calcification.
This projection shows the skull vault, primarily
the frontal bones and the jaws.

12. Technique and positioning
1. The patient is positioned facing the film with the head tipped forwards
so that the forehead and tip of the nose touch the film — the so-called
forehead-nose position. The radiographic baseline is horizontal and at right
angles to the film. This positioning levels off the base of the skull and
allows the vault of the skull to be seen without
superimposition.
2. The X-ray tube head is positioned with the central ray horizontal (0°)
centered through the occiput .

14. Postero-anterior of the jaws (PA jaws/PA mandible)
 This projection shows the posterior parts of the mandible. It is not
suitable for showing the facial skeleton because of superimposition of the
base of the skull and the nasal bones.
Main indications
• Fractures of the mandible involving the
following sites:
— Posterior third of the body
— Angles
— Rami
— Low condylar necks
• Lesions such as cysts or tumors in the
posterior third of the body or rami to note any
medio-lateral expansion
• Mandibular hypoplasia or hyperplasia
• Maxillofacial deformities.

15. Technique and positioning
1. The patient is in exactly the same position as for the PA skull, i.e. the head tipped forward, the
radiographic baseline horizontal and perpendicular to the film in the forehead-nose position.
2. The X-ray tube head is again horizontal (0°),
but now the central ray is centered through the cervical spine at the level of the rami of the
mandible.

17. Reverse Towne's
This projection shows the condylar heads and necks. The original Towne's view (an AP projection) was
designed to show the occipital region, but also showed the condyles. However, since all skull views
used in dentistry are taken conventionally in the PA direction, the reverse Towne's (a PA projection) is
used.
Main indications
• High fractures of the condylar necks
• Intra capsular fractures of the TMJ
• Investigation of the quality of the
articular surfaces of the condylar heads
in TMJ disorders
• Condylar hypoplasia or hyperplasia

18. Technique and positioning
1. The patient is in the PA position, i.e. the head tipped forwards in the forehead-nose
position, but in addition the mouth is open.
The radiographic baseline is horizontal and at right angles to the film. Opening the
mouth takes the condylar heads out of the glenoid fossae so they can be seen.
2. The X-ray tube head is aimed upwards from below the occiput, with the central ray
at 30° to the horizontal, centered through the condyles.

20. This projection shows the skull vault and facial skeleton from the lateral aspect. The main
difference between the true lateral skull and the true cephalometric is that the true lateral skull
is not standardized or reproducible. This view is used when a single lateral view of the skull is
required but not in orthodontics or growth studies.
True lateral skull
Main indications
• Fractures of the cranium and the cranial base
• Middle third facial fractures, to show possible downward
and backward displacement of the maxillae
• Investigation of the frontal, sphenoidal and maxillary
sinuses
• Conditions affecting the skull vault,
particularly:
— Paget's disease
— multiple myeloma
— hyperparathyroidism
• Conditions affecting the sella turcica, such as:
— tumor of the pituitary gland in acromegaly.

21. Technique and positioning
1. The patient is positioned with the head turned through 90°, so the side of the face
touches the film. In this position, the sagittal plane of the head is parallel to the film.
2. The X-ray tube head is positioned with the central ray horizontal (0°) and perpendicular
to the sagittal plane and the film, centered through the external auditory meatus .

23. Submento-vertex (SMV)
This projection shows the base of the skull, sphenoidal
sinuses and facial skeleton from below.
Main indications
• Destructive/expansive lesions affecting the palate, pterygoid
region or base of skull
• Investigation of the sphenoidal sinus
• Assessment of the thickness (medio-lateral) of
the posterior part of the mandible before osteotomy
• Fracture of the Zygomatic arches — to show
these thin bones the SMV is taken with
reduced exposure factors.

24. 1. The patient is positioned facing away from the film. The head is tipped backwards as far as is possible, so
the vertex of the skull touches the film. In this position, the radiographic baseline, is vertical and parallel to
the film.
2. The X-ray tube head is aimed upwards from below the chin, with the central ray at 5° to the horizontal,
centered on an imaginary line joining the lower first molars .
means it is contraindicated in patients with suspected neck injuries .
Technique and positioning

26. Water’s view

28. Panoramic radiography

29. Indications :

31. Intra Oral Radiographic Techniques

32. Periapical
Bitewing
Occlusal

33. Periapical view
Used to record the
 crowns, roots, and surrounding bone.
 Root canal treatment.
 Assessment of root formation and completion.
 Assessment of root morphology.
 Assessment of relationship of roots to various vital structures.
 Implant site assessment and placement.

34. Paralling tech. ( right – angle or Long-cone
Tech. )
Principle:
 The central concept of the paralleling is that “the x-ray receptor is supported
parallel to the long axis of the teeth and the central ray of the x-ray beam is directed at
right angles to the teeth and receptor”.
 minimizes geometric distortion and presents the teeth and supporting bone in their true
anatomic relationships

35. Accuracy
Simplicity
Duplication
ADVANTAGES DISADVANTAGES
Difficult for a beginner
Discomfort
Patient compliance

36. Bisecting Angle Tech.
 The bisecting-angle technique is based on a simple geometric theorem ,Cieszynski ’ s rule
of isometry, which states that two triangles are equal when they share one complete side
and have two equal angles.
 Receptor is positioned as close as possible to the lingual
surface of the teeth, resting in the palate or in the floor
of the mouth.
 The plane of the receptor and the long axis of the teeth
form an angle, with its apex at the point where the
receptor is in contact with the teeth. An imaginary line
that bisects this angle, direct the central ray of the beam
at right angles to this bisector.

37. 1. No film holder required.
2. Better technique for anatomical variations
3. Decreased exposure time.
ADVANTAGES
1. reproduce the length of each root of a
multi-rooted tooth accurately, the central
beam must be angled differently for each
root. (Inaccurate)
2. the alveolar ridge often projects more
coronally than its true position, thus
distorting the apparent height of the
alveolar bone around the teeth.
DISADVANTAGES

38. Object localization
 to obtain three-dimensional information of location
of an object.
1. The right-angle (or cross-section) technique
2. The tube shift technique
buccal object rule and Clark ’ s rule

40. SLOB

42. Bitewing ( interproximal )
Bitewing (also called interproximal ) radiographs include the crowns of the
maxillary and mandibular teeth and the alveolar crest on the same receptor.
Indications :
1.interproximal caries in the early stages.
2. secondary caries below restorations.
3. Overhanging restorations.
4. evaluating the periodontal
condition.(alveolar
bone crest)
5. detecting calculus deposits.

43. Occlusal views
An occlusal radiograph displays a relatively large segment of a dental
arch.
when patients are unable to open the mouth.
localization of objects.
To localize foreign bodies in the jaws and
stones in the ducts.
To demonstrate and evaluate the integrity of
the outlines of the maxillary sinus
To obtain information about the
location, nature, extent, and displacement of
fractures of the mandible and maxilla.
To determine the medial and lateral extent of
disease (e.g., cysts, osteomyelitis, tumors)
and to detect disease in the palate or floor of
the mouth.

54. Thank You
Dr. Rahma Mohammed
Dr. Omer Khairy