This document provides information on radiographic interpretation of dental anatomy and dental materials. It defines radiopaque and radiolucent structures and lists examples of each. Anatomic landmarks seen on radiographs of different tooth areas are described along with common radiographic appearances of dental caries, restorations, and other findings. Diagrams and radiographs are included to illustrate key anatomic structures and conditions. The goal is to teach the fundamentals of identifying normal anatomy and common dental pathologies on dental radiographs.

1. Radiographic Interpretation:
Anatomic Landmarks, Decay, &
Dental Materials

2. • Radiopaque:
• refers to a light area on the film
• –Structures that are absorbers of x-rays block the x-
rays from reaching the film
• –The x-rays are attenuated (decreased in intensity)
by absorbing structures
• –Fewer photons reach the emulsion (less exposure)
• –Dense structures are strong absorbers

3. • •Radiolucent:
• refers to a dark area on the film
• Structures that are less dense are
poor absorbers and allow more
photons to reach the film emulsion
(more exposure)

4. • Radiopaque to Radiolucent
• •Metal
• •Enamel
• •Cementum
• •Dentin
• •Bone
• •Muscle
• •Fat
• •Air
• Restorative and surgical materials have various densities
and abilities to absorb. Metallic materials are more dense
than enamel, thus appear very white on radiographs.

5. SUPPORTING STRUCTURE
• Alveolar crest
• Lamina dura
• Periodontal ligament space
• Cancellous bone

6. Teeth are composed of pulp (arrow on the second
molar), enamel (arrow on the first molar), dentin (arrow on
the second premolar), and cementum (usually not visible
radiographically).
Developing root

7. Radiographic Anatomy Basics:
The Tooth

12. Radiographic Anatomy Basics
Drawing of maxillary midline area. Shown are the (1)
outline of nose, (2) incisive foramen , (3) lateral fossa,
(4) nasal fossa, (5) nasal septum, (6) border of nasal
fossa, (7) anterior nasal spine, and (8) median palatine
suture

14. Radiographic Anatomy Basics
Radiograph of maxillary midline area. This radiograph
shows the (1) incisive foramen, indicated by an irregularly
shaped, rounded radiolucent area. Also seen are the (2)
outline of the nose, (3) lateral fossa, (4) nasal fossa
(radiolucent), (5) nasal septum (radiopaque), (6) border of
nasal fossa, (7) anterior nasal spine, and (8) median
palatine suture

15. Radiographic Anatomy Basics
Drawing of maxillary canine area. The drawing shows
the (1) lateral fossa, (2) nasal fossa, (3) inverted Y
(intersection of the borders of nasal fossa and maxillary
sinus), and (4) maxillary sinus. (5) Note the dense
radiopaque area caused by overlapping of the mesial
surface of the first premolar over the distal surface of the
canine. This overlapping is common in this region of the
oral cavity because of the curvature of the arch.

16. Radiographic Anatomy Basics
Radiograph of maxillary canine area. Shown are the
(1) lateral fossa, (2) nasal fossa, (3) inverted Y, (4)
maxillary sinus, and (5) dense radiopaque area caused
by overlapping

17. Radiographic Anatomy Basics
Soft tissue of the
nose in the path of
the x-ray beam.
Note that the soft
tissue of the nose
will be in the path of
the x-ray beam in
this exposure. The
resultant radiograph
will most likely show
an image of the soft
tissue, outlining the
tip of the nose.

18. Radiographic Anatomy Basics
Soft tissue image of the nose (1). The resultant
image of the soft tissue of the nose is often
magnified to a large size. According to the rules of
shadow casting , the further an object is from the
film packet, the more likely that object will appear
magnified. The tip of the nose is at an increased
distance from the intraoral film packet, resulting in a
magnification of the size of the nose.

19. Radiographic Anatomy Basics
Drawing of
maxillary premolar
area. Drawing
shows the (1) border
(floor) of maxillary
sinus, (2) maxillary
sinus, (3) septum in
maxillary sinus
dividing the sinus
into two
compartments,
(4) zygomatic
process of maxilla,
(5) zygoma, and
(6) lower border of
zygomatic arch.

20. Radiographic Anatomy Basics
Radiograph of maxillary
premolar area. This
radiograph shows the
(1) border (floor) of
maxillary sinus, (2)
maxillary sinus, (3)
zygomatic process of
maxilla, (4) septum in
maxillary sinus dividing
the sinus into two
compartments,
(5) zygoma, and
(6) inferior border of the
zygomatic arch

21. Radiographic Anatomy Basics
Drawing of
maxillary molar
area. Illustrated in
the drawing are the
(1) border (floor) of
maxillary sinus, (2)
maxillary sinus, (3)
zygomatic process
of maxilla, (4)
zygoma, (5) septum
in maxillary sinus,
(6) lower border of
zygomatic arch, (7)
hamulus (hamular
process), (8)
maxillary tuberosity,
and (9) coronoid
process (mandible)

22. Radiographic Anatomy Basics
Radiograph of maxillary
molar area. This
radiograph shows (1)
border (floor) of maxillary
sinus, (2) maxillary sinus,
(3) zygomatic process of
maxilla, (4) zygoma, (5)
lateral pterygoid plate, (6)
lower border of zygomatic
arch, (7) maxillary
tuberosity, and (8)
coronoid process of the
mandible

24. Radiographic Anatomy Basics
Radiograph of maxillary
molar area. This radiograph
shows (1) hamulus (hamular
process), which is a
downward projection of the
medial pterygoid plate, (2)
lateral pterygoid plate, (3)
coronoid process of the
mandible, (4) maxillary
tuberosity, and (5) maxillary
sinus

25. Radiographic Anatomy Basics
Coronoid process of
the mandible may be
imaged on intraoral
radiographs of the
maxillary posterior
region. Note the
position of the film
holder when exposing a
maxillary posterior
periapical radiograph.
The coronoid process
of the mandible will
most likely be imaged
on this radiograph.

26. Radiographic Anatomy Basics
Drawing of mandibular midline area. The
illustration shows (1) mental ridge, (2) nutrient
canal, (3) nutrient foramen, (4) genial tubercles, (5)
lingual foramen, and (6) inferior border of mandible

28. Radiographic Anatomy Basics
Radiograph of the mandibular midline area. This
radiograph shows the (1) mental ridge, (2) nutrient
canal, (3) nutrient foramen, (4) genial tubercles
surrounding the (5) lingual foramen, and (6) inferior
(lower) border of the mandible (radiopaque band of
dense cortical bone).
*Often times when the vertical angulation is
too excessive- you see the cortical bone

29. Radiographic Anatomy Basics
Drawing of mandibular canine area. Illustrated in
the drawing are a (1) nutrient canal, and (2) torus
mandibularis (lingual torus)

30. Radiographic Anatomy Basics
Radiograph of mandibular canine area. A (1) nutrient
canal, and (2) torus mandibularis (lingual torus) are seen
in this radiograph

31. Radiographic Anatomy Basics
Drawing of
mandibular
premolar area. This
drawing shows a (1)
torus mandibularis,
(2) ext oblique ridge,
(3) mylohyoid or
internal ridge, (4)
submandibular
fossa, (5)
mandibular canal,
and (6) mental
foramen

32. Radiographic Anatomy Basics
Radiograph of
mandibular premolar
area. Radiograph
shows the (1)
submandibular fossa,
(2) a thin radiolucent
line indicating the
periodontal ligament
space, (3) thin
radiopaque line
representing the lamina
dura, and (4) the
mental foramen

33. Radiographic Anatomy Basics
Drawing of mandibular
molar area. Drawing
illustrates the (1) ext
oblique ridge, (2)
mylohyoid or internal
ridge, (3) submandibular
fossa, and (4)
mandibular canal

35. Radiographic Anatomy Basics
Radiograph of
mandibular molar area.
Shown are the (1) oblique
ridge (buccal), (2)
mylohyoid ridge (lingual)
(3) mandibular canal, and
(4) submandibular fossa

36. Radiographic Anatomy Basics
Radiograph of
mandibular molar area.
Shown are the
(1) Ext oblique ridge,
(2) mylohyoid or internal
oblique ridge,
(3) mandibular canal and
(4) submandibular fossa

37. Radiographic Anatomy Basics

45. Dental Caries
Vertical
angulation
(A) Improper
vertical angulation
(excessive)
obliterates viewing
this proximal
surface carious
lesion. (B) Proper
vertical angulation
shows interproximal
caries

46. Dental Caries
Horizontal angulation. (1) Improper
horizontal angulation prevents viewing
interproximal caries. (2) Improved horizontal
angulation, but caries difficult to view. (3)
Proper horizontal angulation shows
interproximal caries

47. Dental Caries

48. Interpreting Dental Caries
Diagram of classification of dental caries
(1) Enamel caries less than halfway through the
enamel (incipient caries) (2) Enamel caries penetrated
over halfway through the enamel (moderate caries)
(3) Caries definitely at or through the dentino-enamel
junction (DEJ), but less than halfway through the dentin
toward the pulp (advanced caries).(4) Caries that has
penetrated over halfway through the dentin toward the
pulp (severe caries)

49. Dental Caries

51. RAMPANT
Dental Caries

52. Interpreting Dental Caries
Drawing indicating the area to examine for interproximal caries. To best detect proximal
surface caries, view the area where two adjacent teeth contact, apical down to the area where
the gingival margin would most likely be (boxed area). Cervical burnout is most likely to
be imaged apical to the gingival margin.

53. Root caries?? Can be deceiving …..

54. Radiograph of
occlusal caries.
This radiograph
shows (1) severe
occlusal caries,
which appears as
a large radiolucent
lesion in the first
molar

55. Dental Caries

56. Dental Caries

57. Radiograph of
buccal or lingual
caries. Buccal or
lingual caries on
this mandibular
second premolar
appears as a round
radiolucency
(superimposed over
the pulp chamber)
Dental Caries

58. Radiograph of
cemental (root) caries.
The large radiolucency
on the distal surface of
the distal root of the first
mandibular molar
Dental Root Caries

59. Dental Root Caries

60. Radiograph of
recurrent caries.
This radiograph
shows (1)
radiolucent caries
under the metallic
restoration
Dental Recurrent Caries

61. Conditions Resembling Caries
Bitewing radiograph. This
radiograph shows (1) large
occlusal caries, (2) radiolucent
lines or mach band effect (an
optical illusion caused by
overlapped enamel), (3)
interproximal caries, and
(4) cervical burnout

62. Radiographic Appearance of Dental
Restorative Material

63. Radiographic Appearance of Dental
Restorative Material
Dental materials. This
radiograph shows several
metallic and non-metallic dental
materials. Since all of the metal
restorations are equally
radiopaque, their size and shape
is observed to determine the
type of material. The materials
present in this radiograph are:
(1) amalgam;(2) porcelain-fused-
to-metal crown; (3) post and
core; (4) gutta percha; (5) base
material; (6) full metal crown,
which is the posterior abutment
of a three-unit bridge; (7)
retention pin; and (8) metal
pontic (part of the three-unit
bridge).

64. Restorative Materials

65. Restorative Materials

66. Restorative Materials

67. Restorative Materials

68. This radiograph shows (1) radiolucent restorations
(composites) on the mesial surface of the lateral
incisor and distal surface of the central incisor.
Note that under both restorations is a base of
radiopaque material. (2) The radiolucencies on the
mesial surfaces of both central incisors are carious
lesions.
Restorative Materials & Decay

69. Retention pins. (1) Radiopaque pins help retain the
radiolucent composite restorations. (2) Small radiopaque
amalgam restorations.

70. 70
Restorative Materials

71. Restorative Materials

72. On buccal or lingual?
What kind of crowns?
What is this?!?

73. Restorative Materials

74. Normal bone levels just below CEJ
Bone Levels

75. Bone Levels