8. Radiographic INterpretation Part 2

what are the six relevant nasal structures?

• Nasal septum

• Nasal fossa

• Floor of the nose

• Soft tissue of nose

• Inferior conchae

• Anterior nasal spine

nasal septum

which nasal structure?

• radiopaque shadow midline of nasal cavity

• appears wide and not sharply defined; superimposition of septal cartilage and vomer bone

nasal septum

nasal fossa

which nasal structure?

• Air filled cavity above the roots of maxillary central incisors

• Limited by the nasal septum medially and floor of nasal fossa inferiorly

nasal fossa

anterior nasal spine

which nasal structure?

• Radiopaque V-shaped projection at the base of the nasal septum

• Periapical radiograph of maxillary central incisors

anterior nasal spine

floor of nasal fossa/hard palate

which nasal structure?

radiopaque line extending bilaterally away from base of anterior nasal spine

floor of nasal fossa/hard palate

floor of nasal fossa/hard palate extends anteriorly/posteriorly

posteriorly, superimposed over maxillary sinus

floor of nasal fossa/hard palate

floor of nasal fossa/hard palate

inferior concha/inferior turbinate

which nasal structure?

radiopaque shadow on lateral walls of nasal fossa

inferior concha/inferior turbinate

soft tissue tip of nose

which soft tissue structure of nose?

• Maxillary central-lateral incisor area

• Slightly opaque shadow with sharp border

• Location may be coronal or apical to root apex based on x-ray projection geometry

tip of nose

soft tissue nasolabial fold

which soft tissue structure of the nose?

• Oblique line in maxillary premolar area

• slight opacity (Thick cheek tissue) posterior to the line

soft tissue nasolabial fold

definition: air containing cavity lined w mucus membrane

maxillary sinus/antrum

maxillary sinus

what structure of maxilla?

• Thin, delicate, tenuous radiopaque line

• Thin layer of cortical bone

• Appears continuous in absence of disease

• Close relationship to roots of maxillary posterior teeth

• Roots may appear to project into the sinus however a thin layer of bone covering the root is seen as a fusion of lamina dura and sinus floor

floor of the maxillary sinus

floor of the maxillary sinus

intimate relationship btwn teeth and sinus; periapical infection due to thin layer of cortical bone

T or F: floor of maxillary sinus may extend beyond apices and toward alveolar ridge

true

definition: floor of maxillary sinus extends toward crest of alveolar ridge in response to missing teeth

pneumatization of maxillary sinus

definition: in response to loss of function (tooth loss) sinus may expand farther into alveolar bone

pneumatization of maxillary sinus

pneumatization of maxillary sinus

pneumatization of maxillary sinus

definition: thin folds of cortical bone projecting from sinus floor and wall into the sinus

septae

maxillary septae

Thickening of sinus mucus membrane

CBCT sagittal

what is the Y-line of Ennis?

• formed by nasal fossa floor and antero-medial wall of maxillary sinus

• In periapical radiograph of Canine: The floor of sinus and nasal cavity are superimposed and seen crossing one another forming an inverted Y

• Y-line of Ennis =green line

• black arrow: nasal fossa

• white arrow: anterior border of maxillary sinus

zygomatic process of maxilla

which part of maxilla?

• Extension of lateral maxillary surface

• Serves as articulation for zygomatic bone

• Seen in the apical region of maxillary first and second molars

• U or V shaped thick radiopaque structure

zygomatic process

zygomatic process

zygomatic bone

zygomatic bone

which part of the maxilla has homogenous radiopacity over apices of maxillary molars?

zygomatic bone

side, site, type of radiograph

• side: right

• site: zygomatic process

• type of radiograph:

maxillary tuberosity

pterygoid plates

T or F: Lateral and medial pterygoid plates cast a single radiopaque shadow posterior to tuberosity

true

Lateral and medial pterygoid plates cast a single radiopaque shadow posterior to tuberosity