Normal Anatomic Landmarks Flashcards
Cortical bone
aka compact bone
cortical = outer layer
radiopaque
ex// inferior border of mandible
Cancellous bone
-soft sponge bone located between two layers of dense cortical bone
-lattice like arrangement (composed of bony trabuculae)
-radiopaque
Which type of bone appears more radiolucent, mand or max?
mand
Prominences of bone
radiopaque
-process
-ridge (linear)
-spine (sharp thorn like)
-tubercle (small bump or nodule of bone)
-tuberosity
Spaces and depression in the bone
radiolucent
-canal (tube like passage w blood, nerves)
-foramen (hole/opening in bone)
-fossa (broad shallow depression)
-sinus (hollow space or cavity)
Suture
radiolucent thin line
immovable joint representing union between adjoining bones of the skull
Septum
radiopaque
bony wall or partition separating two spaces or cavities
ex// nasal septum
Floor of nasal cavity
radiopaque
bony wall at base of cavity formed by dense cortical bone
Anterior nasal spine
radiopaque v shape
sharp projection of maxilla at anterior and inferior part of nasal cavity
Inferior nasal conchae
radiopaque
wafer thin curved plates extending from lateral walls of nasal cavity
conchae means shell shaped
Inverted “Y”
radiopaque
dense cortical bone at intersection of wall of mx sinus and wall of nasal cavity
Incisive foramen
radiolucent
aka nasopalatine foramen, small round opening between roots of mx centrals, posterior to the teeth
Superior foramina of incisive canal
2 round radiolucent above apices of mx centrals
tiny holes on floor of nasal cavity, nasopalatine nerves enter through here
Nasal cavity/ Nasal fossa
radiolucent
pear shaped compartment of bone located superior to maxilla
Median palatine suture
radiolucent
immovable joint between 2 halves of the maxilla, extending from alveolar bone between centrals to posterior hard palate
Lateral fossa / Canine fossa
radiolucent
smooth depressed area of maxilla between canine and laterals
Maxillary sinus cavities
radiolucent
paired compartments of bone located within maxilla above mx premolars and molars
Floor of maxillary sinus
radiopaque
composed of dense cortical bone
Septa of maxillary sinus
radiopaque lines
plural or septum
bony walls dividing maxillary sinus into compartments
Tuberosity
radiopaque bulge distal to last molar
rounded prominence of bone extending posterior to 3rd molar
Hamulus / Hamular process
radiopaque hook like distal to tuberosity
hook like projection of bone extending from medial pterygoid plate of sphenoid bone
Zygoma
radiopaque band
cheekbone articulating with the zygomatic process, dense cortical bone
Zygomatic Process of Maxilla
radiopaque J or U shape
bony projection of maxilla articulating with zygoma, dense cortical bone
*may infringe on apices of maxillary molars
Nutrient canals
radiolucent band bounded by 2 radiopaque lines
tiny tubelike passages in bone containing blood vessels and nerves supplying maxillary teeth and interdental areas
Coronoid process of mandible
radiopaque triangle in mx tuberosity region
bony prominence of anterior ramus, attachment site for one of the mastication muscles
Ramus
vertical portion of mandible posterior to 3rd molar area
Body of Mandible
horizontal shaped portion extending from ramus to ramus
Alveolar process
portion of mandible that encases and supports the teeth
Genial tubercles
radiopaque ring
tiny bumps of bone serving as attachment site for muscles, on lingual aspect of mandible
Mental ridge
radiopaque bands
linear prominence of cortical bone on external surface of anterior portion of mandible
premolar region to the midline, slopes slightly upward
Lingual foramen
radiolucent dot by apices of md incisors
tiny hole in bone on internal surface of mandible, located near midline supported by genial tubercles
Nutrient canals (md)
radiolucent vertical lines
tubelike passageway through bone containing nerves and blood vessels
interdental nutrient canals more often seen in mn due to thin bone
*more seen radiographically on edentulous mandible
Mental fossa
radiolucent area above mental ridge
scooped out area on external surface of anterior mandible
Mylohyoid ridge
radiopaque band
linear prominence of bone on internal surface of mandible, from molar region down and forward to lower border of mandibular symphysis
attachment site for mylohyoid muscle
Internal oblique ridge
radiopaque band
linear prominence of internal surface of mandible extending downward and forward from the ramus
may end at 3rd molar region or continue as mylohyoid ridge
External oblique ridge
radiopaque band
linear prominence of bone located on external surface of body of mandible
anterior border of ramus extend into this ridge
*may be superimposed on each other, external is the superior
Mental foramen
radiolucent ovoid area in apical region of md premolars
*may be misdiagnosed at periapical abscess
hole in bone on external surface of mandible, exit for blood vessels and nerves supplying lower lip
Mandibular canal
radiolucent band outlined by 2 thin radiipaque line (cortical walls of canal)
tubelike passageway through bone traveling length of mandible, travels from mandibular foramen to the mental foramen and contains inferior alveolar nerve and blood vessels
Submandibular fossa
radiolucent area in molar region below mylohyoid ridge
scooped out area on internal surface of mandible, submandibular salivary gland found here
Enamel
outermost radiopaque layer of crown
Dentin
radiopaque
makes up most of tooth structure
Dentinoenamel junction (DEJ)
like where very radiopaque enamel meets less radiopaque dentin
Pulp cavity
radiolucent
consists of pulp chamber and pulp canals, contains blood vessels nerves and lymphatics
Lamina dura
radiopaque line
wall of tooth socket surrounding root of tooth, dense cortical bone
Alveolar crest
radiopaque
most coronal portion of alveolar bone found between the teeth, dense cortical bone, 1.5-2mm below CEJ
Periodontal Ligament Space
radiolucent line around root of tooth
space between root of tooth and lamina dura, contains connective tissue fibers, blood vessel, and lymphatics
*healthy PDL appears as continuous radiolucent line of uniform thickness
Anterior alveolar crest
appears pointed and sharp
Posterior alveolar crest
appears flat and smooth
