1. The document describes several normal radiographic anatomical landmarks seen on dental radiographs. 2. Key landmarks described include the nasal septum, anterior nasal spine, incisive foramen, lamina dura, alveolar crest, periodontal ligament space, and cancellous bone in the jaws. 3. Landmarks of the mandible discussed are the lingual foramen, genial tubercles, mental ridge, mental foramen, mylohyoid ridge, and mandibular canal.

1. NORMAL
RADIOGRAPHIC
ANATOMICAL
LANDMARKS
DR. DIVYA RANA

2. a
b
c
a : enamel
B : dentin
C : pulp

3. Cervical burnout :
Radiographs sometimes show
Diffuse radiolucent areas
With ill defined borders
Present on mesial n distal
Aspects of teeth in cervical
region
These regions appear between
The edge of the enamel cap
And the crest of the alveolar
Ridge.
It should not be confused with
Root caries.

4. Lamina dura:
It is a thin radio-opaque Layer Of dense bone surrounding the
Tooth socket.
It is thicker than the surroundingTrabecular bone and thickness
Increases with increase in amount In the occlusal stress

5. Alveolar crest
The gingival margin of the
Alveolar process that extends
Between the teeth is
Apparant on radiographs
As radiopaque line called
Alveolar crest.
It is considered as normal
If it is not > than 1.5 mm
From cej of adjacent teeth.

6. Periodontal ligament space
PDL space is primarily composed of collagen, so appers as radiolucent
Space between tooth root and lamina dura.

7. Cancellous bone : it lies between the cortical plates in both the jaws.
It is composed of thin radiopaque plates and rods surronding many
Small radiolucent marrow spaces.

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Landmarks of maxilla
median palatine suture
Nasal fossa
Nasal septum
Anterior nasal spine
Incisive foramen
Lateral fossa
Maxillary sinus
Malar bone
Maxillary tuberosity
Hamular process
Nasolacrimal duct

9. Maxillary anterior region
Nasal septum
Nasal fossa
Nasal spine
Insicive foramen
Nose
Median palatine suture

10. A-Nasal septum
B-Nasal fossa
C-Anterior nasal spine
D-Incisive foramen
E-Median palatine suture
a
b
c d
e

11. Nasal cavities Nasal
septum
Anterior nasal spine
Median palatine suture

12. 1 .Nasal septum (17): appears as a
radio-opaque line that separates
the two nasal fossa in the
midline.
2. Anterior nasal spine (16): appears
as aV-shaped radio-opaque
structure in the midline above
the incisive foramen.
3. Incisive foramen (12): or the
anterior
palatine fossa, it usually appears
as a prominent radiolucent area
above or between roots of two
central incisors, it usually
appears
round or oval in shape and
doesn’t
exceed 6mm in diameter.

13. Palatal view
Median palatine suture

14. Median palatine suture
Appears as a vertically oriented
Radiolucent line in true image
projections through the midline.
Usually prominent between the
two central incisor roots in
Young individuals.

15. Palatal view
Incisive foramen

16. Red arrow points to
periapical lesion
periapical cyst

17. Red arrow :mesiodens mesiodens

18. Incisive canal cyst

20. Facial view
Nasal septum

21. Facial view
Nasal fossa

22. Soft tissues of nose

23. Red arrow : soft tissues of nose
Green arrow :lip line

24. Floor of nasal fossa
Maxillary sinus
Lateral fossa
Nose
Maxillary canine

25. a: Floor of nasal fossa
b: Maxillary sinus
c: Lateral fossa
a
b
c

26. Floor of nasal fossa (red arrow) and anterior border of
maxillary sinus (blue arrows),forming the inverted
(upside down )Y

27. Lateral fossa : the radiolucency results from a depression
Above and posterior to the lateral incisor.To help rule
Out a pathology, look for an intact lamina dura
Surrounding the adjacent bone.

28. The maxillary sinus surrounds
The root of the canine,
Which may be misinterpreted
As pathology.
Black arrows indicate the floor
of the nasal fossa ,the max
sinus (red arrows) has
pneumatized bet the 2nd PM
And 1st molar.

29. Sinus
septum
Zygomatic
process
Maxillary sinus
Maxillary premolar region

30. a: Malar process
c: Sinus septum
d: Maxillary sinus
a
c
d
a c
d

31. Maxillary sinuszygoma
ptrygoid plate
Hamular process
Coronoid process maxillary tuberosity
Maxillary molar region

32. Maxillary sinus :
The maxillary sinus with
Its thin bony walls, its
thin mucosa, and its vast
Air space, produce an
Extremely dark image
Deep to the maxillary
Teeth.
Its outlines, particularly its
Floor, are clearly delineated
By delicate radio-opaque
lines

33. 1- body of zygoma
6- apices of roots
7 - floor of the sinus
8- septum of the sinus
molar region

34. In general ,the floor of the sinus is
Approximately coincidental with
The location of the apices of the
Roots of the upper teeth (bicuspids
And first two molars ).
But there is often as much as two
Or even three mm of maxillary
Bone between the root ends and
Sinus floor.

35. In other cases the sinus floor dips so deeply between the roots of the
Maxillary teeth that the latter appear to project into it for as much as
One half of their length

36. Pneumanization :expansion of sinus wall into surrounding
bone, usually in an area where teeth have been lost
prematurely.
It increases with age .

37. a
c
d
e
g
e
g
d
c a
b
f
f
A :max tuberosity e : zygoma (dotted lines)
B :coronoid process f : max sinus
C : hamular process g :sinus recess
D: pterygoid plates
Image of the imacted third molar superimposed

38. Malar (zygomatic) process. U or j- shaped
Radio-opacity, often superimposed over the roots
Of the molars, specially when using the bisecting
Angle technique.The red arrows define the
Lower border of the zygomatic bone.

39. Maxillary tuberosity : the rounded elevation located at the
posterior aspect of both sides of the maxilla.

40. Malar bone : or the zygomatic
Process.The inferior portion
Of the malar bone appears
As a radio-opaque, U shaped structure
Related to the roots of the first
Maxillary molar. It represents the
Attachment of the zygomatic bone
To the maxilla.
Maxillary tuberosity: appears
As a radio-opaque structure that
Extends distally and upward from
Posterior to maxillary sinus. It
Represents the end of maxilla.

41. Black arrows : hamular process
Purple arrows : pterygoid plates

42. Coronoid process : it is seen as a radio-opaque structure in
maxillay molar iopa.

43. Hamular process:
It is a bony spine extending from
Pterygoid process of the sphenoid
Bone. It appears as a radio-opaque
Spine that is recorded on radiographs
Distal to the tuberosity of maxilla
And extends downward.
Coronoid process of the mandible:
Appears as a triangular radio-
opaque structure projected into the
same general area of max
periapical film projections distal to
the maxillary teeth.

44. The zygomatic process (green) is a U shaped rationality. Normally
the Zygomatic bone posterior to this is very dense and radio-
opaque. In this, however the max sinus has expanded into the
zygomatic bone and makes the area more radiolucent (red).The
coronoid process (orange), the pterygoid plates (blue) and the max
tuberosity (pink) are also identified .

45. Nasolacrimal duct :
It is seen in occlusal view
of the maxilla as a round
radiolucent area
superimposed on the
posterior region of the
hard palate.

46. Landmarks of mandible
Lingual foramen
Genial tubercles
Mental ridge
Mental foramen
Mental fossa
External oblique line
Internal oblique line
Mylohyoid line
Mandibular foramen
Inferior alveolar canal
Submandibular gland fossa
Nutrient canals

47. Mandibular symphysis
In a new born infant
Symphysis
Fracture

48. Mandibular incisor region
mental fossa
Lingual foramenGenial tubercle
Mental ridge

49. a
b
cd
C :mental ridge
D: mental fossa
A: lingual foramen
b: genial tubercles

50. Lingual foramen : radiolucent ‘hole ’ in centre of genial tubercles.
Lingual nutrient vessels pass through this foramen .

51. Lingual foramen
It is set in the midline deep
To the apices of the
Anterior teeth.
It appears as a small
Radiolucent dot at the
Symphysis area usually
Surrounded by a radio
Opaque structure.

52. Genial tubercles : radio-opaque area in the midline surrounding
The lingual foramen

53. Genial tubercles:They appear as radio Opaque circle that surrounds
the lingual foramen just below the apices of the Of the incisors.

54. mental ridge

55. Mental ridge :
it is a bony prominence found on the labial
Aspect of the mandible near its inferior border and extended
From the premolar region to the symphysis area on wchich
It takes an upward turn as it approaches it. It appears as a
Radio opaque line below the apices of anterior teeth.

56. mental fossa : this represents the depression on the labial
aspect of the mandible overlying the roots of the incisors.The
resultant radiolucency may be mistaken for pathology

57. Nutrient canals :
The arrows above identify
nutrient
Canals.
They are most often seen in
Persons with thin bone and in
Those with high blood
pressure
Or advanced periodontitis.
Nutrient canals

58. Mental foramen (3)
It appears as a radiolucent,
ill defined area between
the apices of bicuspids.
it represents the anterior
Terminates of the mandibular
canal.

59. 6- caries
7- prepared cavity
8- enostosis
9 –mental foramen

60. Mandibular premolar region
A – mylohyoid ridge
B - mandibular canal
c – submandibular gland fossa
d – mental foramen

61. b -Mandibular canal
d -Mental foramen
a- Mylohyoid ridge
c -Submandibular gland fossa
d
b a
c

62. mental
foramen

63. Mandibular molar region
A – external oblique ridge
B – mylohyoid ridge
C – mandibular canal
D- submandibular gland fossa

64. A -External oblique ridge
c -Mandibular canal
B - Mylohyoid ridge
D -Submandibular gland fossa
a
c
b
d

65. External oblique ridge - a continuation of the anterior border of ramus
passing downward and forward on the buccal side of the mandible.
It apperas as a radio-opaque line which usually ends anteriorly in the
Area of the first molar.
The red arrow points to the mylohyoid ridge.

66. The external oblique ridge (red) and the mylohyoid ridge (blue)
Usually run parallel to each other , with the external oblique ridge
Always being higher on the film .

67. Internal oblique ridge -
It appears as a radio opaque
Line, descending downwards
And forward from coronoid
Process, in a horizontal
Position, stop at the third
Molar area or become cotinuous
With the mylohyoid line
Its placed below the external
Oblique ridge.

68. Mylohyoid ridge (internal oblique) – located on the lingual
Surface of the mandible , extending from third molar area
to Premolar region

69. Mandibular canal : arises at the mandibular foramen on the
Lingual side of the ramus and passes downward and forward,
Moving from the lingual side in the third molar region to the
buccal Side in the premolar region.
It contains the inferior alveolar nerves and vessels.

70. The mandibular canals (red arrows) usually runs very close to the molars
Green arrow showing dilaceration of roots.
The other film shows impaction at the superior border of the canal .

71. Bifid mandibular canal:
a) cone beam section
b) Cross section

72. Submandibular gland fossa

73. Submandibular gland fossa -
It is a depression on the lingual
Aspect of the mandible on which
Submandibular glands are
Present.
It appears as a zone of
Radiolucency below the
Lower molars

74. A – external oblique ridge
B – mylohyoid ridge
c – mandibular canal
D – submandibular gland fossa
a
b
c
d

75. THANK YOU
PRESENTED BY: DR. DIVYA RANA