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NORMAL RADIOGRAPHIC
APPEARANCE OF
ANATOMICAL STRUCTURES
OF THE MANDIBLE
• Course: 1)Theoretical basis
2)Break
3)Computer program(quiz)for
learning
• Method: 1) Presentation
2) Dental Radiographic Anatomy
program
MENTAL RIDGES OR TUBERCLES
(radiopaque-light)
The mental protuberances are triangular
eminence of denser bone on the inferior,
anterior aspect of the mandible. These raised
portions of bone on either side of the midline
form the mental ridges or tubercles.
GENIAL TUBERCLES OR MENTAL SPINE(1)
AND LINGUAL FORAMEN(2)
1-radiopaque-light,2-radiolucent-dark
The genial tubercles are located on the inner
surface of the body of the mandible in the
midline.These tubercles are the points of
insertion of the genioglossus and geniohyoid
muscles bilaterally to the upper and lower
genial tubercles respectively. On a periapical
radiograph, the genial tubercles appear as
roundish, localized areas of increased density
with a small, dark round spot in the middle
representing the small radiolucent lingual
foramen for the passage of small lingual
nutrient vessels.
Superior margin of the lower
lip
Nutrient canals
MANDIBULAR (INCISIVE) LATERAL
FOSSAE
(radiolucent-dark)
The two incisive fossae represent depressions
in the
outer surface of the alveolar bone between the
mandibular canine teeth.
MENTAL FORAMEN
( radiolucent-dark)
The mental foramen conducts the mental
vessels and nerves.A circular radiolucent area is
seen below the premolar teeth on either side,
midway between the upper and lower border of
the body of the mandible.The location varies
from the distal of the canine to the second
premolar area. It may be located at the apex of
either premolar and may resemble periapical
pathology of pulpal origin.
White arrows outline the mental foramen.
Black arrows outline apical pathology which is
secondary to pulpal exposure from coronal caries.
MANDIBULAR CANAL OR INFERIOR
ALVEOLAR CANAL
( radiolucent-dark)
The mandibular canal starts at the
mandibular foramen on the inner
aspect of the ramus and passes in a
downward and forward direction
through the mandible.
As it passes forward, it also moves
from the lingual side of the body of
the mandible in the third molar area
to the buccal side in the premolar
region.In the region of the mental
foramen the mandibular nerve
bifurcates into its twoterminal
branches known as the incisive and
mental nerves
1. Mandibular foramen.
2. Mandibular canal.
3. Mental foramen.
EXTERNAL OBLIQUE LINE OR
RIDGE
(radiopaque-light)
This ridge(2) is located on the
buccal side of the mandible and
may be followed in an obliquely
upward direction from the mental
tubercle to the anterior border of
the ramus(1).It is seen as a
radiopaque line of varied width
and density that passes across
the molar region.
MYLOHYOID LINE OR RIDGE
(radiopaque-light)
The mylohyoid ridge is located on
the lingual aspect of the mandible
and is sometimes referred to as the
internal oblique ridge. It serves as
the point of attachment for the
mylohyoid muscle of the floor of the
mouth and extends from the molar
region to the premolar area.It is
seen below the apices of the molar
teeth and the external oblique ridge.
White arrows indicate external oblique ridge
Black arrows delineated internal oblique ridge
Submandibular fossa
inferior border of the mandibule
CORONOID PROCESS OF MANDIBLE
(radiopaque-light)
This structure is a thin, triangular eminence of
the mandible that is flattened lateromedially. The
coronoid process is sometimes seen (as here)
on a the maxillary posterior molar periapical
radiograph.
Black arrows delineate margin of coronoid process
White arrows delineate border of mucous retention cyst of
maxillary sinus.
This is not a normal anatomic feature but is a common
benign finding.