Anatomical Landmarks--practical examination configuration of the tooth, it ... mandible in this...

Radio-anatomy

Presented by

Mohamed El-Sherbini

A, Enamel; B, Dentin; and C, CementoA, Enamel; B, Dentin; and C, Cemento--enamel junction.enamel junction.

The pulp space

Teeth are composed of pulp (arrow on the second molar),

enamel (arrow on the first molar), dentin (arrow on the second premolar), and cementum (usually not visible radiographically).

A developing root shown by a divergent apex, around the dental

papilla (arrow), which is enclosed by an opaque bony crypt.

A developing root

Hypercementosis of the roots of a mandibular molar

may occurs in Paget’s disease.

Cervical burn-out may be due to

anatomical configuration of the tooth, it should be differentiated from cervical caries

Lamina dura

Periodontal membrane space

Alveolar crest is pointed at the anterior teeth.

Alveolar crest is flattened at the posterior

teeth and parallel to the cemento-enamel junction of adjacent teeth.

The median palatine (intermaxillary) suture is found

between the two palatine processes of the maxilla.

Intermaxillary suture (arrows) appears as a radiolucency in the

midline of the maxilla surrounded by two radiopaque borders.

The anterior nasal spine is seen as an opaque V-

shaped projection from the floor of the nasal fossa in the midline (arrow).

The nasal septum appears as a radiopaque partition

that divides the nasal cavity.

The anterior floor of the nasal fossa (arrows) appears

as opaque lines extending laterally from the anterior nasal spine.

The inferior nasal conchae appear as diffuse radiopacities within

the nasal cavity.

The incisive foramen appears radiolucent.

The superior foramina of the incisive canal appear as small

rounded radiolucency above the root apices of the maxillary central incisors.

Lateral fossa is a diffuse radiolucency (arrows) in the region of

the apex of the lateral incisor. It is formed by a depression in the maxilla at this location.

The soft tissue outline of the nose (arrows) is

superimposed on the anterior maxilla.

The nasolacimal canals are commonly seen as ovoid

radiolucencies (arrow) on maxillary occlusal projections.

The naso-lacrimal canals (arrow) is occasionally seen near the

apex of the canine when steep vertical angulation is used. Note the mesiodens (supernumerary tooth) superior to the central incisor.

The inverted Y appears as a radiopaque upside-

down Y.

The maxillary sinus inferior border.

Septa within the maxillary sinus appear as radiopaque lines.

This bony nodule (arrow) is a normal variant of the floor of the

maxillary sinus.

This x-ray shows a recent extraction socket (of the upper right first molar) complicated by dislodgement of the distobuccal root into the antral cavity. This accident occurs frequently and an operation should be arranged at the earliest opportunity to retrieve the displaced root and effect surgical repair of the oro-antral fistula. Early operation will prevent the occurrence of irreversible chronic changes in the mucosa of the maxillary sinus.

The zygomatic process of the maxilla (arrows) extends

posteriorly from the inferior portion of the zygomatic process of the maxilla.

The maxillary tuberosity appears as a radiopaque bulge distal to

third molar region.

Pterygoid plates (arrows) located posterior to the

maxillary tuberosity.

Mandibular symphysis (arrows) in a newborn infant. Note the

bilateral supernumerary primary incisors adjacent to it.

Genial tubercles (arrow) on the lingual surface of the

mandible in this cross-sectional mandibular occlusal view.

The mental ridge appears as a radiopaque band in the premolar

and incisor region.

The mental fossa appears as a radiolucent area above the mental

ridge.

The mental foramen (arrow, over the apex of the second

premolar) may simulate periapical disease. Continuity of the lamina dura around the apex, however, indicates the absence of periapical abnormality.

The mylohyoid ridge appears as a radiopaque band or

line above the submandibular gland fossa.

Mandibular canal (arrows), radiopaque superior and inferior cortical border.

Submandibular gland fossa (arrows) indicated by a poorly

defined radiolucency and sparse trabecular bone below the mandibular molars.

The external oblique ridge appears as a radiopaque

band.

The inferior border of the mandible (arrows) is seen as a

dense, broad radiopaque band.

Left, the coronoid process appears as a triangular-shaped radiopacity. Right, superimposition of the coronoid process on the tuberosity area resemble root

fragment (white arrow).

Amalgam restoration appears completely radiopaque

(arrows).

Stainless steel pins (arrows) provide retention for

amalgam restoration.

A cast gold crown, appearing completely radiopaque

(arrow), serves as the terminal abutment of a bridge.

Gutta-percha (arrows) is a radiopaque rubber-like material used in endodontic therapy.

Silver points (arrow) were used to fill the root canals in

this patient.

Porcelain appears radiolucent (arrow) over a coping.

Composite restorations containing particles of barium glass are

radiopaque and net likely to be confused with caries.

Orthodontic appliances have a characteristic

radiopaque appearance.