Normal Radiographic Anatomy

2. Tooth anatomy
Supporting structures
Anatomical landmarks

3. Teeth are composed primarily of dentin, with an enamel cap over
the coronal portion and a thin layer of cementum over the root
surface.
Radiographic Appearance of Enamel

ENAMEL appears more radio-opaque than other tissues.
It is 90% mineral causes greator attenuation of X-ray photons.

4. 75% mineral content less radiopaque than enamel.
Radiopacity similar to bone.
ENAMELODENTINAL JUNCTION appears as a distinct
interface separating these two structures.

5. 50%mineral content and it appears as a very thin layer on the root
surface.
It is usually not so apparent radiographically.
CERVICAL BURNOUT
Radiographs sometimes show diffuse radiolucent areas
with ill defined borders present on the mesial or distal
aspects of the teeth in the cervical region.
These regions appear between the edge of the enamel cap
and the crest of the alveolar ridge.

6. Normal configuration of the affected teeth, results in
decreased X-ray absorption in the areas in question.
Perception of these areas is due to contrast with the
adjacent ,relatively radiopaque enamel and alveolar –
bone.
It should not be confused with root caries which has
similar appearance.

7. It is composed of soft tissues so it appears
radiolucent.
Pulp chambers and root canals extend from the
interiors of the chamber till the root apices.
It is seen radiographically also as apical foramen.
In some cases, it may exit on the side of the canal.
Lateral canals may end at the apex as a discernible
foramen or may exit at the side of the root.

8. ENAMEL
PULP
DENTIN

9. The pulp canals of a developing tooth root diverge and walls of the root
taper to a knife edge.
A radiolucent area is seen surrounding it in the trabecular bone. It is
surrounded by the hyperostotic bone.
IT IS THE DENTAL PAPILLA WITH ITS BONY CRYPT .
Its radiographic evaluation helps in determining the stage of maturation
of the developing tooth.

10. Periodontal ligament
space
Lamina dura
Alveolar crest
Trabecular bone

11. It is composed of collagen so appears as a radiolucent space
between the root and lamina dura.
It is thinner in the middle of the root and slightly wider near
the alveolar crest and the apex ,suggesting that the fulcrum
of the physiologic movements is in the region where PDL is
thinnest.

12. It is a thin radiopaque layer of dense bone surrounding the tooth socket.
Its radiographic appearance is due to attenuation of the X-ray beam as it
passes tangentially through the thickness of the bone.
It is thicker than the surrounding trabecular bone and thickness increases
with increase in amount of occlusal stress.

13. It is the radiopaque gingival margin of the alveolar
process which surrounds the teeth.
It is considered normal if it is 1.5mm or less from the
CEJ.
It shows apical recession with the age or periodontal
disease.

14. Also called as the trabecular bone or the spongiosa.
Lies between the cortical plates in both the jaws.
It is composed of thin radiopaque plates and rods surrounding many small
radiolucent pockets of marrow.
In posterior maxilla, it is similar to anterior maxilla but marrow spaces are
larger.

15. ANATOMIC LANDMARKS OF
MAXILLA

Intermaxillary suture

Anterior nasal spine

Nasal fossa and Nasal septum

Incisive foramen

Superior foramina of nasopalatine canal

Lateral fossa
 Nose

Nasolacrimal canal

Maxillary sinus

Zygoma & zygomatic process of maxilla

Nasolabial fold

Pterygoid plates

16. Also called as median suture.
In IOPA, it appears as a thin radiolucent line in the midline between the
two portions of premaxilla.
It extends from the alveolar crest between the central incisors superiorly
through the anterior nasal spine and continues posteriorly between the
maxillary palatine process to the posterior aspect of the hard palate.

17. Mostly seen on IOPA of maxillary central incisors.
Located in midline1.5-2cm above the alveolar crest.
It is radiopaque and usually V-shaped.

18. The nasal cavity shows the hazy shadow of the inferior nasal
conchae extending from the right and left lateral walls
Floor of Nasal
Fossa
Nasal
Septum

19. Also called as NASOPALATINE or ANTERIOR PALATINE
FORAMEN.
It is the oral terminatus of the nasopalatine canal.
It transmits the nasopalatine vessels and nerves.
Lies in the midline of palate behind the central incisors at the
junction of the median palatine and incisive sutures.
Radiographic image variability is due to:
1.Different angles of the X-ray beam.
2.Variability in its anatomic size.
IT IS FREQUENTLY THE POTENTIAL SITE
OF CYST FORMATION.

20. The nasopalatine canal originates at two foramina in floor of the
nasal cavity.
Radiographically, it can be recognized as two radiolucent areas
above the apices of the central incisors in floor of the nasal cavity
near its anterior border and both the sides of the septum.
Lateral wall of
nasopalatine
canal
Superior
foramina

21. Also called as INCISIVE FOSSA.
Appears as depression in the maxilla near the apex of the
lateral incisor .
Appears diffusely radiolucent in the IOPA.

22. The nasal and maxillary bones form the nasolacrimal canal.
It runs from the medial aspect of the antero inferior border
of the orbit inferiorly, to drain under the inferior conchae
into the nasal cavity.

23. The soft tissue of the nose is frequently seen in the
projections of the maxillary central and lateral incisors
,superimposed over the roots of these teeth.
Image appears uniformly opaque with a sharp border.

24. An oblique line demarcating a region that
appears to be covered by a slight radio opacity
frequently traverses periapical radiographs of
the premolar region.

25. MAXILLARY SINUS is an air containing cavity lined by
mucous membrane.
Appears as the three sided pyramid .
Base -formed by mesial wall adjacent to nasal cavity.
Apex –extending laterally into the zygomatic process of
maxilla.

26. On the IOPA, maxillary sinus appears as a thin ,delicate
radiopaque line.
It extends from the distal aspect of the canine to the
posterior wall of the maxilla above the tuberosity.
Around the age of puberty, its floor coincides with the floor
of the nasal cavity.

27. In response to the loss of function (associated with loss of
posterior teeth) the sinus may expand further into the
alveolar bone , occasionally extending to the alveolar ridge.
Thin radiolucent lines of the uniform width are found within
the image of the maxillary sinus.
These are shadows of the neuro -vascular canals that
accommodate the posterior superior vessels and nerves.

28. The zygomatic process of the maxilla is an extension of the
lateral maxillary surface that arises in the region of the
apices of the first and the second molars and serves as the
articulation for the zygomatic bone.
Appears as a U-shaped radiopaque line with rounded ends
projected in the apical region of the first and second molars.

29. The medial and lateral pterygoid plates lie immediately posterior
to the tuberosity of maxilla.

They cast a single radiopaque shadow without any evidence of
trabeculation.
Extending inferiorly from the medial pterygoid plate, the hamular
process may be seen.

30. Symphysis
Genial tubercles
Lingual foramen
Mental ridge
Mental fossa
Mental foramen
Mandibular canal
Nutrient canals
Mylohyoid ridge
Submandibular gland fossa
External oblique ridge
Inferior border of mandible
Coronoid process

31. The region of mandibular symphysis in infants demonstrate
a radiolucent line through the midline of the jaw between
the images of the forming deciduous central incisors.
The suture usually fuses by the end of 1
st
year of life and is no
longer radiographically apparent.

32. These are tiny bumps of bone that serve as attachment for
the genioglossus and geniohyoid muscles.
Present on lingual side.
On IOPA, appears as ring shaped radiopacity below the
apices of mandibular incisors.

33. It is a hole or tiny opening located on the internal
surface of mandible and surrounded by the genial
tubercles.
Radiographically, appears as a radiolucent dot
inferior to the apices of the mandibular incisors.

34. It is a linear prominence of cortical bone located on
the external surface extending from the premolar
region to the midline and slopes upward.
Radiographically, appears as a radiopaque band that
extends from the premolar region to the incisor
region.

35. Located above the mental ridge.
On peri apical radiograph, appears as a radiolucent area
above the mental ridge.

36. Located on the external surface of the mandible as an
opening in the region of the mandibular premolars.
Mental nerves and blood vessels exit through it.
Radiogarphically, it appears as a small ovoid radiolucent
area located below the apices of the premolars.

37. Tube like passage extending from the mandibular foramen
to the mental foramen and contains inf.alv. Nerves and
blood vessels.
Appears as a radiolucent band outlined by two radiopaque
lines of cortical plate.

38. Nutrient canals are tube like passage-ways through bone
that contains nerves and blood vessels that supply the teeth.
Radiographically seen as vertical radiolucent lines.
More prominent in anterior mandible where bone is thin.

39. Linear prominence of bone located on the internal surface of
mandible.
Extends from the molar region downward and forward
towards the lower border of mandibular symphysis.
On IOPA, appears as radiopaque band extending downward
from molars.

40. Linear prominence of bone located on external surface of
mandible extending downwards and is a continuation of
anterior border of ramus.
It appears as a radiopaque band extending downwards and
forwards from ant. border of mandible & ends in 3
rd
molar
region.

41. Depressed area of bone located on the internal surface of
mandible.
Submandibular salivary gland lies in this fossa.
It appears as a radiolucent area in the molar region below the
mylohyoid ridge.

42. Linear prominence of bone located on
internal surface of mandible extending
downwards and forwards from ramus.
It appears as a radiopaque band extending
downwards from ramus.

43. Occasionally, seen as a dense broad radiopaque
band of bone.

44. It is a marked prominence of bone on the ant. ramus of the
mandible.
Not seen on a mandibular IOPA but appears on a maxillary
molars IOPA.
It is seen as a triangular radiopacity superimposed over or
inferior to maxillary tuberosity.

45. Vary in their radiographic appearance.
Depend primarily on their thickness, density and atomic
number.
A variety of restorative materials may be recognized on intra
oral radiographs.

46. Thank You