Landmarks on Dental X-Rays

Walls of sinus

Appears radiopaque

Sinus cavity

Appears radiolucent

Incisive foramen / nasopalatine foramen

Appears between the roots of the central incisor & looks like a round oval less than 1 cm in diameter

Seen on maxillary central incisor PA’s

Nasal fossae

Appears radiolucent. Seen on maxillary central incision PA’s and somewhat on lateral incisor and canine PA’s

Median palatine suture

Appears as a thin vertical line in the midline on max central incisor PA’s

Is where the two halves of the maxillary come together

Maxillary tuberosity

Is the rounded end of the alveolar process of the maxilla

Coronoid process

Anterosuperior portion of the ramus

Seen when the patient’s mouth is open on posterior maxillary PA’s

Mental foramen

Located below roots of mandibular premolars.

Is the opening for passage of the mental nerve and vessels.

Often misinterpreted as periapical lesions

External Oblique Ridge

Bony anterior border of the ramus located n the outer aspect of the mandible

Mental Ridge

Prominence of bone on the labial surface of the anterior mandible

Some individuals display very distinct ridges while others have little or no evidence of its presence.

Seen on incisor and partially on lateral aspect of canine PA’s

Zygomatic Process (malar process)

Radiopaqe U-shaped structure representing where the zygomatic bone attaches to the maxilla

Seen on maxillary premolar and molar PA’s

Trabelculae

Interconnected spongy bone (bony lines) that appear like fuzzy bright lines and dark spaces

Mandibular canal

Pathway in the bone where the inferior alveolar nerve and blood vessels flow through the mandible.

Extend from mandibular foramen within the ramus to the mental foramen.

Appears radiopaque

Submandibular gland fossa

Depression in the bone on the lingual aspect of the posterior mandible.

Bilateral below the maternal oblique ridge/mylohyoid line.

Is where the submandibular salivary gland rests.

Typically appears radiolucent

Nutrient canals

Internal Oblique Ridge / Mylohyoid line

Bony ridge found on the lingual aspect of the posterior mandible. Ranges from highly to barely visible.

Hamular process

aka pterygoid hamulus

Tiny finger/hook like projection of bone extending from medial pterygoid plate.

Appears on maxillary molar PA’s and molar bitewings

Lingual foramen

Small pinpoint opening in bone on the lingual aspect of anterior mandible.

Surrounded by genial tubercle.

(for lingual nerve and arteries)

Mandibular Retromolar pad

Genial tubercles

aka mental spine

Spiny protuberance (sometimes 2) of bone located in the midline on the lingual aspect of mandible below roots of incisor teeth

Hyoid bone

Sometimes appears as a ghost image above the mandible

Inverted Y

Depicts where the nasal fossa crosses the maxillary sinus (the boundary between them are shaped like a upside down Y)

Anterior Nasal Spine

Appears “V-shaped” or “triangular point”

Is a bony projection located at the base of the nasal septum in the maxillary midline

Lateral fossa / canine fossa

Appears bilaterally

Is a slight dip or depression in the bone on the labial of the maxilla near the lateral roots

Recorded don lateral and canine PA’s

Tori

Tissue appears radiopaque

Pterygoid plates

Located behind maxillary tuberosity

“thin wing bone” extending posteriorly from tuberosity

Mental fossa

Depression in the bone on the labial aspect of the mandible.

Diffuse radiolucent appearance above the mental ridge

prominence based on thickness and density of mandible