Ch27 Intraoral Images Flashcards
Cortical bone
Also known as compact bone
Dense outer layer of bone
Appears radiopaque on dental images
Inferior border of the mandible is made of cortical bone
Cancellous bone
Soft spongy bone between two layers of cortical bone
Has a lattice look and this space is filed with bone marrow
The lattice or trabeculae will also appear radiopaque
5 types of bony prominences
Process Ridge Spine Tubercle Tuberosity
Process
Marked prominence or projection of bone
Coronoid process of mandible
Ridge
Linear prominence or projection of bone
Oblique ridge of mandible
Spine
Sharp, thorn-like projection of bone
Nasal spine of maxilla
Tubercle
Small bump or nodule of bone
Mental tubercles of the mandible
Tuberosity
Rounded prominence of bone
Maxillary tuberosity
4 types of spaces and depressions in bone
Canal
Foremen
Fossa
Sinus
Canal
Tubelike passageway through bone that contains nerves and blood vessels
Mandibular canal
Foremen
Opening or hole in bone that permits the passage of nerves and blood vessels
Mental foremen of the mandible
Fossa
Broad, shallow, scooped out or depressed area of bone
Submandibular fossa of mandible
Sinus
Hollow space, cavity or recess in bone
Maxillary sinus
Septum
Bony wall or partition that divides two spaces or cavities
May be within a fossa or sinus
Will appear radiopaque
Nasal septum
Suture
Immovable joint that represents a line of union between adjoining bones of the skull
Median palatine suture of maxilla
Incisive foramen
Opening or hole in bone located at the midline of the anterior portion of the hard palate directly posterior to the maxillary central incisors
Appearance: on an anterior maxillary PA image is appears small, ovoid or round radiolucent area located between the roots of the maxillary central incisors
Superior foramina of the incisive canal
Two tiny openings or holes in bone located on the floor of the nasal cavity. Openings of two small canals that extend downward and medically from the floor of the nasal cavity. Join together to form the incisive canal and exit together at the incisive foramen
Appearance: on an anterior maxillary PA image it appears as two small, round radiolucencies superior to the spices of maxillary central incisors
Median palatal suture
Immovable joint between the two palatine processes of the maxilla. Extends from the alveolar bone btw the maxillary central incisors to the posterior hard palate
Appearance: on an anterior maxillary PA image the median palatal suture appeared as a thin radiolucent line btw the maxillary central incisors. Maybe less distinctive as patient ages
Lateral fossa
Smooth depressed area of maxilla located just inferior and medial to the infraorbital foramen btw the maxillary and central incisors
Appearance: appears as a radiolucent area between the maxillary canine and lateral incisor. Not visible in all patients
Nasal cavity
Pear shaped compartment of bone located superior to the maxilla. Floor of the nasal cavity is formed by the palatal process of the maxilla and the horizontal portions of palatine bones. Lateral walls are formed by ethmoid bone and the maxillae. Divided by the nasal septum
Appearance: large radiolucent area superior to the maxillary incisors
Nasal septum
Vertical bony wall or partition that divides the nasal cavity into the left/right nasal fossaez formed by cartilage and two ones—vomer and a portion of the ethmoid bone
Appearance: vertical radiopaque partition that divides nasal cavity
Floor of nasal cavity
Bony wall formed by the palatal processes of the maxilla and the horizontal portions of palatine bones. Composed of dense cortical bone and defines the inferior border of the nasal cavity
Appearance: floor of nasal cavity appears as dense radiopaque bone superior to the maxillary incisors
Anterior nasal spine
Sharp projection of the maxilla located at the anterior and inferior portion of the nasal cavity
Appearance: appears as a v-shaped radiopaque area located at the intersection of the floor of the nasal cavity and nasal septum
Inferior nasal conchae
Wafer thin, curbed plates of bone that extend from the lateral walls of the nasal ca it’s. Seen in the lower lateral portions of the nasal cavity.
Appearance: appears as diffuse radiopaque masses or projections within the nasal cavity
Maxillary sinus
Paired cavities or compartments of bone located within the maxilla. Located superior to maxillary premolar and molar teeth. Rarely extends beyond canines
Appearance: appears as a radiolucent area located superior to the spices of maxillary premolars and molars. Floor of maxillary sinus is composed of dense cortical bone
Septa within maxillary sinus
Maybe seen within the maxillary sinus lo bony walls or partitions that appear to divide the maxillary sinus into compartments
Appearance: radiopaque lines within the maxillary sinus. Sometimes appear as distinct lines in others none are seen. Varies by individual
Nutrient canals within maxillary sinus
Tiny tubelike passageways through bone which contain blood vessels and nerves that supply maxillary teeth and interdental areas
Appearance: appears as a narrow radiolucent band bounded by two thin radiopaque lines. Lines represent cortical bone that makes up walls of the canal
Inverted Y
Refers to the intersection of the maxillary sinus and the nasal cavity as viewed on a dental image
Appears as a radiopaque upside down Y formed by the intersection of the lateral wall of the nasal fossa and the anterior border of the maxillary sinus
Maxillary tuberosity
Rounded prominence of bone that extends posterior to the third molar region. Blood vessels and nerves enter the maxilla in this region to supply posterior teeth
Appearance: radiopaque bulge distal to the third molar region
Hamulus
Small hooklike projection of bone extending from the medial pterygoid plate of the sphenoid bone. Posterior to maxillary tuberosity
Appearance: radiopaque hook-like projection posterior to maxillary tuberosity area
Zygomatic process of maxilla
Bony projection of maxilla that articulates with the zygoma, or molar bone. Composed of dense cortical bone
Appearance: J or U-shaped radiopacity located superior to the maxillary first molar region
Zygoma
Cheekbone. Articulates with the zygomatic process of the maxilla. Composed of dense cortical bone
Appearance: appears as diffuse radiopaque band extending posteriorly from the zygomatic process of the maxilla
Sections of the mandible
Ramus
Body
Angle
Alveolar process
Ramus
Vertical portion of mandible that is found posterior to the third molar
Body of mandible
Horizontal u-shaped portion that extends from ramus to ramus
Angle of mandible
Corner portion formed by the junction of posterior and lower borders of ramus
Alveolar process of mandible
Portion that encases and supports teeth
Genial tubercles
Tiny bumps of bone that serve as attachment sites for the genioglossus and geniohyoid muscles. Located in the lingual aspect of the mandible
Appearance: appears as a ring-shaped radiopacity inferior to the spiciest of the mandibular incisors
Lingual foramen
Tiny opening or hole in. One located on the internal surface of the mandible. Located near the midline and is supported by genial tubercles
Appearance: appears as small, radiolucent dot located inferior to the spiciest of the mandibular incisors. Surrounded by genial tubercles which appear as a radiopaque ring
Nutrient canals
Tubelike passageways through bone that contain nerves and blood vessels that supply teeth.
Appearance: vertical radiolucent bands. Readily seen in areas of thin bone
Mental ridge
Linear prominence of cortical bone located on the external surface of the anterior portion of the mandible. Extends from premolar region to the midline and slopes slightly upward
Appearance: appears as thick radiopaque band that extends from the premolar region to the incisor region
Mental fossa
Scoped put, depressed area of bone located in the external surface of the anterior mandible. Located above the mental ridge in the mandibular incisor region
Appearance: radiolucent area above the mental ridge. Appearance of the mental fossa varies and is determined by the thickness of the bone I the anterior region of the mandible
Mental foramen
Opening or hole in bone located in the external surface of the mandible in the region of the mandibular premolars. Blood vessels and nerves that supply the lower lip exit here
Appearance: small, ovoid or round radiolucent area located in the apical region of the mandibular premolars. May be misdiagnosed as a periodical lesion because of its location
Mandibular Canal
Tube like passageway through bone that travels the length of the mandible. Extends from the mandibular foramen to the mental foramen and houses the inferior alveolar nerve and blood vessels
Appearance: appears as a radiolucent band. Two thin radiopaque lines that represent the cortical walls of the canal outlined the mandibular canal
Mylohyoid ridge
Linear prominence of bone located on the internal surface of the mandible. The mylohyoid ridge extends from the third molar region downward and forward to the second premolar area. Serves as an attachment site for the muscles of the same name
Appearance: dense radiopaque band that extends downward and forward from the third molar region at the level of the spices of the posterior teeth. Appears most Orrin the molar region
External oblique ridge
Linear prominence of bone located on the external surface of the body of the mandible. Anterior border of the ramus ends here.
Appearance: radiopaque band extending downward and forward from the anterior border of the ramus. Typically ends in the mandibular third molar region. May also be viewed on molar bitewings
Anterior border or the ramus
Extends vertically downward from the coronoid process to the external oblique ridge
Appearance: on a bitewing, the descending ramus of the mandible may be seen as slightly radiopaque vertical band posterior to the maxillary and mandibular molars
Submandibular fossa
Scooped out, depressed area of bone located on the internal surface of the mandible inferior to the mylohyoid ridge. Submandibular salivary gland is found here
Appearance: radiolucent area in the molar region below the mylohyoid ridge. Few trabeculae seen here
Coronoid process
Marked prominence of bone on the anterior ramus. Serves as an attachment site for one of the muscles of mastication
Apply: not seen on a mandibular periapical but may appear on a maxillary molar PA. Appears as a triangular radiopacity superimposed over or inferior to, the maxillary tuberosity region
Enamel
Densest structure in the human body. Outermost radiopaque layer of the crown of a tooth
Dentin
Found underneath the enamel layer and surrounds the pulp cavity.
Appears radiopaque and makes up the majority of the tooth structure. Not as radiopaque as enamel
Dentino-enamel junction
Junction between the dentin and the enamel of a tooth. The DEJ appears as a line where the enamel meets the dentin
Pulp cavity
Consists of pulp chamber and pulp canals. Contains blood vessel, nerves and lymphatic a and appears relatively radiolucent on a dental image.
Generally larger in children than adults
Alveolar bone
Bone of the maxilla and mandible that encases the roots of teeth. Composed of dense cortical bone and cancellous bone
Anatomical landmarks of the alveolar process
Lamina dura
Alveolar crest
Periodontal ligament space
Shape and density of alveolar bone
Lamina dura
Wall of tooth socket that surrounds the root of a tooth. Made of dense cortical bone
Appearance: appears as dense radiopaque line that surrounds the root of a tooth
Alveolar crest
Most coronal potion of alveolar bone found between teeth. Made up of dense cortical bone and is continuous with the lamina dura
Appearance: appears radiopaque and typically located 1.5 to 2.0mm below the junction of the crown and root surfaces
Periodontal ligament space
Space btw the tooth of the tooth and the lamina dura. The PDL space contains connective tissues fibers, bloods vessels and lymphatics
Appearance: appears as a thin radiolucent line around the root of a tooth
Shape and density of alveolar bone
Anterior region: healthy alveolar crest appears pointed and sharp between teeth. Appears as dense radiopaque line in the anterior region
Posterior region: appears flat and smooth between teeth. Tends to appear less dense and less radiopaque than in the anterior region
Primary dentition
“Baby teeth”
20 teeth. 10 mandibular and 10 maxillary
Smaller and whiter
Roots flare to make room for permanent teeth
Pulp chambers are larger
Permanent dentition
“Adult teeth”
32 teeth. 16 mandibular and 16 maxillary
Mixed dentition
Includes both primary and permanent teeth
Between ages 5 and 12 when primaries fall out and permanent teeth grow in
This period can create different dental concerns like crowding, spacing issues, malocclusion TMJ dysfunction and increased plaque and gingivitis due to brushing difficulties
