It’s time for… Intraoral Radiographic Anatomy
Steven R. Singer, DDS 212.305.5674 [email protected]
“Alas, poor Yorick!”
Radiographic Contrast Radiographic Contrast
The difference in densities between adjacent areas of the image Influenced by:
! Subject contrast
! Film contrast
! Beam energy and intensity
! Fog and scatter radiation
Radiographic Contrast Radiographic Contrast
By adjusting kVp, contrast can be By adjusting kVp, contrast can be varied varied ! High contrast films can enhance ! Low contrast films can enhance detection of lesions where subject contrast detection of subtle findings. between the lesion and healthy tissue is low ! Examples include: ! Examples include: " Calculus " Caries " Soft tissue outlines " Apical lucencies " Small changes in crestal bone
1 Radiographic Density Radiographic Density
The overall degree of darkening of the Exposure
radiographic image. Three factors ! Determines the # of photons that are which determine radiographic density absorbed by the emulsion are: ! Four exposure factors
! Exposure " kVp " ma ! Subject thickness " Impulses (time) ! Object density " Source to film distance
Radiographic Density Radiographic Density
Subject thickness Object Density. The denser the object and higher the atomic #, the better the absorption of photons.
Radiographic Density Subject Contrast
In decreasing order of density: Influenced by:
! Metallic restorations Thickness
! Enamel Density ! Dentin Atomic # ! Bone ! Fat/fluid Relatively differences in Subject ! Air Contrast of oral structures allow the image to be seen
2 Subject Contrast Definitions
Radiodensity: The degree to which the subject attenuates the x-ray beam Radiopacity: An area of the image where the beam has been relatively highly attenuated Radiolucency: An area of the image where the beam has been relatively minimally attenuated
Radiolucencies Radiopacities
Marrow spaces Fossae Bone Teeth Foramina Meati Condyles Enamel Canals (N.B. the Sinuses Eminences Dentin Processes walls of the canal Sutures Cementum Tuberosities are opaque) Dental pulp Fissures Walls of canals Tubercles Ridges Trabeculae
The Teeth The Teeth
Enamel 90% mineralized Enamel Dentin 75% mineralized Dentin Cementum 50% mineralized Pulp Pulp Soft tissue
3 The Teeth The Teeth
Cervical burnout Concavities
Supporting Structures of the The Teeth Teeth Trabecular bone Fluting of root surfaces
Bone in the Anterior Maxilla Bone in the Posterior Maxilla
Trabeculae are thin and numerous Similar pattern to anterior maxilla Small marrow spaces Slightly larger marrow spaces
4 Bone in the Anterior Mandible Bone in the Posterior Mandible
Trabeculae are somewhat thicker than in the maxilla Horizontal Plates Plates are in a horizontal pattern Larger marrow spaces than anterior mandible
Supporting Structures of the Supporting Structures of the Teeth Teeth
Crestal bone
Supporting Structures of the Supporting Structures of the Teeth Teeth
Lamina dura The joint between Periodontal the tooth and the ligament space bone is a gomphosis. The periodontal ligament allows for movement around a center of rotation.
5 Supporting Structures of the Landmarks Teeth
Lamina dura and PDL
facial view palatal view Landmarks in the Maxilla f b c f Intermaxillary suture e Nasal Fossa a d e Nose Lateral fossa
a = nasal septum e = incisive foramen b = inferior concha f = median palatal c = nasal fossa suture d = anterior nasal spine
Landmarks in the Maxilla Pterodactyl gr. pteron, wing
Incisive foramen Median palatine suture Pterygoid plates
6 Landmarks in the Maxilla Coronoid Process
Anterior nasal spine From the Greek word for “Crow’s Beak” Zygomatic process Pterygoid plates Coronoid process of the mandible Nasolabial fold
Maxillary Incisor Landmarks in the Maxilla a Latyeral pterygoid b plate a = nasal septum c b = inferior concha Pterygo-maxillary d c = nasal fossa fissure e d = anterior nasal spine Zygomatico- e = incisive foramen f = intermaxillary suture temporal suture g = soft tissue of nose Zygomatic process f of the maxilla
g
facial view Landmarks in the Maxilla
Intermaxillary suture Soft tissue of the nose Incisive foramen
Nasal fossa
7 Landmarks in the Maxilla Landmarks in the Maxilla
Soft tissue of the The red arrows nose point to the soft tissue of the nose. The green arrows identify the lip line.
Landmarks in the Maxilla Landmarks in the Maxilla
Foramina of Nasopalatine canal von Ebner
Landmarks in the Maxilla Landmarks in the Maxilla
Incisive foramen Incisive foramen
8 Maxillary Canine Landmarks in the Maxilla a
b a = floor of nasal fossa c b = maxillary sinus c = lateral fossa d = soft tissue of the nose
d Anterior nasal spine
facial view Landmarks in the Maxilla
Lateral fossa
Lateral fossa. The radiolucency results from a depression above and posterior to the lateral incisor. To help rule out pathoses, look for an intact lamina dura surrounding the adjacent teeth.
Maxillary Premolar Landmarks in the Maxilla a b c Nasal Fossa a = zygomatic process of maxilla b = sinus septum c = sinus recess d = floor of the maxillary sinus e = maxillary sinus
d e
9 Maxillary Premolar facial view
a b c b b c d c d a = zygomatic a a process of maxilla b = sinus septum c = sinus recess d = floor of the maxillary sinus e = maxillary sinus a = zygomatic process b = sinus recess d e c = sinus septum d = floor of the maxillary sinus
Maxillary Molar Landmarks in the Maxilla
Nasolabial fold a = maxillary tuberosity e f b = coronoid process c = hamular process d d = pterygoid plates c
e = zygoma b a f = maxillary sinus
Landmarks in the Maxilla Landmarks in the Maxilla
Zygomatic Process and Maxillary Sinus Zygomatic Process and Maxillary Sinus
10 Pneumatization. From the Latin “filled with air” Expansion of sinus wall into surrounding bone, usually in areas where teeth have been lost prematurely. Increases with age. Mucositis Halo effect
Landmarks in the Maxilla Landmarks in the Maxilla
Maxillary tuberosity Hamular process Coronoid process of the mandible
Hamular process Tuberosity
Hamular process Hamular process Tuberosity
Coronoid Process
facial view Landmarks in the Mandible
Mental ridges Mental foramen Mental fossa Maxillary Tuberosity. The rounded elevation located at the posterior aspect of both sides of the maxilla.
11 Mandibular Incisor The Thinker Auguste Rodin, 1881
a. lingual foramen b. genial tubercles c. mental ridge d. mental fossa
d
a bc
Landmarks in the Mandible Landmarks in the Mandible
Mental foramen Mylohyoid (Internal Inferior alveolar oblique) ridge (Mandibular) Submandibular canal gland fossa Inferior border of the mandible
Landmarks in the Mandible Landmarks in the Mandible
External oblique Genial tubercles ridge Mental Ridge Inferior border of the mandible
12 lingual view lingual view facial view Lingual view Facial view Landmarks in the Mandible
d c b a a b a
a = lingual foramen c = mental ridge a = Lingual foramen b = Mental ridge b = genial tubercles d = mental fossa
facial view Mandibular Canine
a = mental ridge c b = genial tubercles/ lingual foramen c = mental foramen
Mental fossa. This represents a depression on the b labial aspect of the mandible overlying the roots of the a incisors. The resulting radiolucency may be mistaken for pathosis.
facial view lingual view lingual view
dbb2 da dc db1 Lingual foramen/ genial tubercles.
a = mental ridge b1 = genial tubercles c = mental foramen b2 = lingual foramen
13 facial view Landmarks in the Mandible
Inferior border of the mandible
The red arrows identify the mandibular canal and the blue arrow points to the mental foramen.
Mandibular Premolar Landmarks in the Mandible
Submandibular gland fossa
a = mylohyoid ridge b = mandibular canal c = submandibular gland fossa d = mental foramen
Mandibular Molar Landmarks in the Mandible
Mental Foramen and Inferior Alveolar Canal
a = external oblique ridge b = mylohyoid ridge c = mandibular canal d = submandibular gland fossa
14 facial view Landmarks in the Mandible a bb External oblique ridge Internal oblique ridge (a.k.a mylohyoid ridge)
c d a = external oblique ridge b = mylohyoid ridge c = mandibular canal d = submandibular gland fossa
lingual view
b a
d c Mylohyoid (internal oblique) ridge. This radiopaque ridge is the attachment for the mylohyoid a = external oblique ridge muscle. The ridge runs downward and forward from the b = mylohyoid ridge third molar region to the area of the premolars. c = mandibular canal (inferior border) d = submandibular gland fossa
facial view
External oblique ridge. A continuation of the anterior border of the ramus, passing downward and forward on The mandibular canal (red arrows identify inferior border of the buccal side of the mandible. It appears as a distinct canal) usually runs very close to the roots of the molars, radiopaque line which usually ends anteriorly in the area especially the third molar. of the first molar. Serves as an attachment of the buccinator muscle. (The red arrows point to the mylohyoid ridge).
15 Restorations Restorations
Gold Metallic Restorations Amalgam Bases and liners Titanium Stainless Steel Gutta Percha Porcelain Composites Cements and Liners
Restorations Restorations
Implant restorations Stainless steel post Root-end amalgam
Restorations Restorations
Porcelain Composites: Radiolucent and Radiopaque Gold Gutta percha Stainless steel
16 Restorations Acknowledgement
Posterior composites Thanks to OSU College of Dentistry for the use of some of the slides, diagrams, and radiographs.
Questions Thank you!
Thanks!
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