Occlusal and Skull Radiography Flashcards

1
Q

• Display a relatively large segment of a dental arch
• Indications:
1. Location of supernumerary, unerupted and impacted teeth
2. Location foreign bodies in the jaws and floor of the mouth
3. Identify and determine the full extent of disease in the
jaws, palate and floor of the mouth
4. To monitor intermaxillary suture during palatal expansion.
5. To detect sialoliths (sublingual or submandibular glands)
6. To evaluate the walls of the maxillary sinuses.
7. To aid in the examination of patients with trismus
8. To visualize fractures in the maxilla and mandible.

A

Occlusal Radiographs

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2
Q

What size plate should be used for occlusal radiograph?

A

4

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3
Q
• Image field: 
• Anterior maxilla and 
its dentition
• Teeth from canine to 
canine
• Anterior portion of  the 
floor of  the nasal cavity
A

Anterior max occlusal projection

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4
Q

• Receptor placement:
• Sagittal plane of the patient perpendicular to
the floor
• Occlusal plane parallel to the floor
• Posterior portion on the receptor is touching the
ramus
• The long dimension of the receptor is
perpendicular to the sagittal plane of the patient
• Stabilize the receptor by gently closing the
mouth

A

ANterior max occlusal projection

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5
Q
Projection of  the central ray:
• Central ray through the tip of the
nose towards the middle of the
receptor
• Approximately +45 degrees of
vertical angulation and 0 degrees of
horizontal angulation
A

Anterior max occlusal projection

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6
Q
Image field:
• Palate
• Zygomatic process of  the maxilla 
• Part of  the maxillary sinuses
• Nasolacrimal canals
• Teeth from 2nd molar to 2nd molar
• Nasal septum
A

Cross sectional max occlusal projection

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7
Q

Receptor placement:
• Sagittal plane of the patient perpendicular to
the floor
• Occlusal plane parallel to the floor
• Posterior portion on the receptor is touching
the ramus
• The long dimension of the receptor is
perpendicular to the sagittal plane of the
patient
• Stabilize the receptor by gently closing the
mouth

A

Cross sectional max occlusal projection

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8
Q
Projection of  the central ray:
• Vertical angulation: +65 degrees
• Horizontal angulation: 0 degrees
• Directed to the bridge of the nose,
just below the nasion towards the
middle of the receptor
A

Cross sectional max occlusal projection

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9
Q
Image field:
• A quadrant of  the maxilla
• Maxillary sinus
• Tuberosity
• Teeth from lateral incisor to the 
contralateral 3rd molar
• Zygomatic process of  the maxilla 
(superimposed over the root of  the 
molars)
A

Lateral Max Occlusal Projection

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10
Q

Receptor placement:
• Receptor perpendicular to the patient’s
sagittal plane.
• Push the receptor posteriorly until it touches
the ramus
• Position the lateral border of the receptor
parallel with the buccal surfaces of the
posterior teeth, extending laterally
approximately 1 cm past the buccal cusps.
• Close the mouth gently

A

Lateral Max Occlusal Projection

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11
Q
Projection of  the central ray:
• Vertical angulation: +60 degrees
• Orient the central ray to a point 2
cm below the lateral canthus of the
eye, directed towards the center of
the receptor
A

Lateral Max Occlusal Projection

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12
Q
Image field: 
• Anterior portion of  the 
mandible
• Dentition from #22 to #27
• Inferior border of  the mandible
A

Anterior Mandibular Occlusal Projection

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13
Q
Receptor placement:
• Patient is tilted back → the
mandibular occlusal plane is 45
degrees from the floor
• Push the receptor posteriorly until it
touches the ramus
• Close the mouth
A

Anterior Mandibular Occlusal Projection

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14
Q

Projection of the central ray:
• -55 degrees to the receptor
• Place the PID in the midline
and through the tip of the chin

A

Anterior Mandibular Occlusal Projection

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15
Q
Image Field:
• Soft tissue of the floor of the
mouth
• Lingual and buccal plates of the
mandible from 2nd molar to 2nd
molar
• When this view is made to
examine the floor of the mouth
(e.g., for sialoliths), the exposure
time should be reduced to half
A

Cross-sectional Mandibular

Occlusal Projection

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16
Q
Projection of  Central Ray: 
• Central ray at the midline
through the floor of the mouth
• Approximately 3 cm below the
chin
• Right angle to the center of the
receptor
A

Cross-sectional Mandibular

Occlusal Projection

17
Q
Receptor Placement: 
• Patient’s head tilted back so that the ala-
tragus line is almost perpendicular to the 
floor.
• Push the receptor posteriorly until it
touches the ramus
• The anterior border of the receptor
should be approximately 1 cm beyond
the mandibular central incisors.
• Close the mouth
A

Cross-sectional Mandibular

Occlusal Projection

18
Q
Image Field: 
• Soft tissue of  half  the floor of  the 
mouth
• Buccal and lingual cortical plates 
of  half  of  the mandible
• Teeth from the lateral incisor to 
the contralateral 3rd molar
A

Lateral Mandibular Occlusal

Projection

19
Q

Receptor Placement:
• Patient’s head tilted back (ala-tragusline almost perpendicular to the floor)
• Push the receptor posteriorly
• Shift the receptor (right or left) so thatthe lateral border of the receptor isparallel with the buccal surfaces of theposterior teeth and extends laterallyapproximately 1 cm.
• The anterior border of the receptor →
1 cm beyond the mandibular incisors.
• Close the mouth

A

Lateral Mandibular Occlusal

Projection

20
Q
Projection of  Central Ray: 
• Central ray perpendicular to the
receptor
• Approximately 3 cm below the
chin
A

Lateral Mandibular Occlusal

Projection

21
Q

• X-ray source and receptor are placed outside the patient’s
mouth (both remain static)
• Why?
• To examine areas not fully covered by intraoral radiographs
like the cranium, facial bones and cervical spine
• Limited mouth opening
• Growth assessment
• Determine relationship between facial and dental structures
Dental caries and periodontal disease cannot be evaluated

A

Skull radiographs

22
Q
The following are \_\_\_\_\_ radiographs
1. Lateral cephalometric
2. Posteroanterior 
cephalometric
3. Cadwells
4. Water’s projection
5. Reverse Towne
6. Submentovertex
A

Skull radiographs

23
Q

What is the line that is used to correctly position patient taking skull radiographs?

A

Canthomeatal line

24
Q
▪ Most commonly used.
▪ Lateral view of  skull, 
teeth and soft tissue. 
Indications:
-Orthodontics (growth 
and development)
-Facial soft-tissue profile
-Orthognathic surgery 
evaluation
-Anterior-posterior view 
of  the paranasal sinuses
Identify:
- Frontal, ethmoidal, 
maxillary and sphenoid 
sinuses
A
  1. Lateral Cephalometric
25
Q

Image receptor Parallel to the pt. mid-
sagittal plane.
X- ray beam centered External auditory
meatus

A

Lateral Cephalometric

26
Q
Indications:
• Evaluation of  facial 
asymmetries.
• Assessment of  skull 
fractures.
• Assessment of  
orthognathic surgery 
outcomes. 
Identify:
• Orbits
• Nasal cavity
• Frontal sinuses
A
  1. Posteroanterior cephalometric
27
Q

Image receptor In front of the pt. and
perpendicular to the
mid-sagittal plane.
X- ray beam centered Nasal bridge

A

Posteroanterior cephalometric

28
Q

• It is an angled posteroanterior
radiograph of the skull
• Used to see the frontal sinuses.

A

Caldwell view

29
Q
Image receptor The patient's forehead 
is placed against the 
image detector.
X- ray beam centered Angled around 15° to 
nasal bridge
CML should be parallel to floor: 
Beam should be 15-20 degrees above CML
A

Caldwell view

30
Q
• Indication: evaluation of  the sinuses
Image receptor In front of  the pt. and 
perpendicular  to the 
mid-sagittal plane.
X- ray beam is centered Maxillary sinus.  
Head tilted upwards
37 degree angulation of CML from beam
A

Water’s projection

31
Q
Indications:
Assessment of  the condylar 
area:
• Fracture.
• Hypoplasia/hyperplasia
Image receptor In front of  the pt. and 
perpendicular  to the 
mid-sagittal plane.
X- ray beam is centered At condylar level .  
Open mouth
CML at -30 degree angle compared to beam
A

Reverse Towne’s view

32
Q
Indications:
• Evaluation of  the sphenoid 
sinuses.
• Lesions of  the palate 
• Evaluate fracture of  the 
zygomatic arch (underexposed 
image)
Image receptor Parallel to the 
patient’s transverse 
plane.
X- ray beam is centered Below the mandible 
and toward the vertex 
of  the skull.
CML parallel to floor
A

Submentovertex

33
Q

To see a zygomatic arch fracture, should you under or overexpose?

A

Underexpose