Dental Care Flashcards
radiolucent
black on radiographic images
structures that appear radiolucent (3)
cavities, depressions or openings in bone such as a sinus, fossa, canal or foramen will allow x-rays to penetrate through them and expose the receptor
radiopaque
white on radiographic images
structures that appear radiopaque
bony in origin absorb or stop the penetration of the x-rays and, therefore, do not reach the receptor
maxillary landmarks (5)
anterior nasal spine incisive foramen inverted y zygomatic process hamular process
Anterior nasal spine –
The anterior nasal spine (ANS) is a bony projection located at the base of the nasal septum in the maxillary midline. Radiographically, the ANS appears as a V-shaped or triangular point radiopacity. This structure is recorded on maxillary central incisor periapicals.
Incisive foramen –
The incisive or nasopalatine foramen is located in the midline on the lingual aspect of the hard palate above the central incisor teeth crowns. The foramen is the termination of the nasopalatine canal. Radiographically, it appears between the roots of the central incisor teeth as a round to oval radiolucency less than one centimeter in diameter. It has a range of sizes and shapes, so variation is not unusual. This structure is recorded on maxillary central incisor periapicals.
Inverted Y –
The inverted Y is a radiographic landmark that depicts where the nasal fossa crosses the maxillary sinus. The boundary between them is shaped like an upside-down letter Y, hence its name. The periapicals below demonstrate the inverted Y, a classic radiographic landmark of the right and left anterior maxilla. The fossa is positioned toward the midline while the sinus extends toward the posterior aspect of the maxilla. Typically, the inverted Y sits apical to the maxillary lateral incisor and canine teeth. No comparable structures are found in the mandibular lateral incisor and canine areas which differentiates maxillary from mandibular anterior periapicals.
Zygomatic process -
The zygomatic process is the radiopaque U-shaped structure representing where the zygomatic bone attaches to the maxilla. The zygomatic process of the maxilla is the most anterior aspect of the zygomatic bone. The process is positioned toward the midline while the bone extends posteriorly away from the midline. This structure is sometimes referred to as the malar process and can be seen on maxillary premolar and molar periapicals.
Hamular process –
The hamular process or pterygoid hamulus is a tiny finger or hook-like projection of bone that extends inferiorly from the medial pterygoid plate. This bilateral radiopacity occasionally appears on maxillary molar periapicals and molar bitewings when the receptor is positioned sufficiently posterior to record it.
mandibular landmarks (4)
genial tubercles
mental foramen
mandibular canal
mental ridge
Genial tubercle –
The genial tubercle is a spiny protuberance or prominence (sometimes two) of bone located in the midline on the lingual aspect of the mandible below the roots of the incisor teeth. This structure serves as the locus of attachment for the genioglossus and geniohyoid muscles. Although variable in appearance, the tubercle often produces a ring-like or doughnut-shaped radiopacity on mandibular incisor periapicals. The genial tubercle is also referred to as the mental spine.
Mental ridge –
The mental ridge is a prominence of bone on the labial surface of the anterior mandible. This structure presents as an inverted V-shaped radiopaque ridge that extends from the premolar to canine area on each side meeting in the midline. The mental ridge varies in its presentation with some individuals displaying very distinct ridge anatomy while others, little or no evidence of its presence. This mandibular landmark can be recorded on incisor and partially on the lateral aspect of canine periapicals.
Mental foramen –
The mental foramen, the primary landmark of this area, is a circular radiolucent structure located below the roots of the mandibular premolar teeth. This structure is the opening for passage of the mental nerve and vessels and can be observed on mandibular premolar and the lateral aspect of canine periapicals. This bilateral radiolucency can be misinterpreted as a periapical lesion. However, it is easily differentiated upon closer examination of the tooth and its supporting structures.
Mandibular canal –
The mandibular canal is the pathway in bone where the inferior alveolar nerve and blood vessels course through the mandible. The canal extends from the mandibular foramen (This foramen is not recorded on mandibular periapicals.) within the ramus anteriorly to the mental foramen. This tubular bilateral radiolucency often demonstrates fine radiopaque boundaries. The mandibular canal is recorded on mandibular premolar and molar periapicals. It is also referred to as the inferior alveolar nerve canal.
