Downloaded 320 times
More Related Content
Similar to Radiographic Anatomical Landmarks
Radiographic Anatomical Landmarks
- 1.
- 2. The radiographicrecognition of diseases requires a sound knowledge of the radiographic appearance of normal structure. Intelligent diagnosis mandates an appreciation of the wide range of variation in the appearance of normal anatomic structure. Most patients demonstrate many of the normal radiographic landmarks, but it is rare patient who shows them all. Accordingly, the absence of one or two or even several landmarks in any individual should not necessarily be considered abnormal.
- 3. Normal Tooth Anatomy Enamel:Enamel is the densest structure found in the human body. Enamel is the outer most radiopaque layer of the crown of the tooth. Dentine: Dentine is found beneath the enamel layer of the tooth and surrounds the pulp cavity. Dentine appears radiopaque and comprises most of the tooth structure
- 4. Dentinoenamel junction (DEJ): Itis the junction between the dentine and the enamel of a tooth. The DEJ appears a line where the enamel (very radiopaque) meets the dentine (less radiopaque).
- 5.
- 6. The alveolar process,or alveolar bone, serves as the supporting structure for the tooth of the jaws. The alveolar bone: is the bone of the maxilla and mandible that supports and encases the root of teeth. Alveolar bone is composed of dense cortical bone and cancellous bone. Supporting structures:
- 7. Types of bone A)Cortical bone Cortical bone, also referred to as compact bone, is the dense out layer of bone. Cortical bone resists the passage of X-ray beam, and appears radiopaque on the radiograph. The inferior border of the mandible is composed of cortical bone and appears radiopaque.
- 8. Cortical bone appearsvery radiopaque on a dental radiograph
- 9. B) Cancellous bone Cancellousbone is the soft spongy bone located between two layers of dense cortical bone. Cancellous bone is composed of numerous bony trabeculae that form a lattice like network of intercommunicated spaces filled with bone marrow. The trabeculae resist the passage of the X- ray beam and appear radiopaque; in contrast, the marrow spaces permit the passage of X ray beam and appear radiolucent.
- 10. Cancellous bone appears predominantlyradiolucent
- 11. The anatomic landmarksof the alveolar process include the lamina dura, the alveolar crest and the periodontal ligament space. Anatomy of alveolar bone:
- 12. Alveolar crest: The alveolarcrest is the most coronal portion of the alveolar bone found between the teeth. It is made up of dense cortical bone and is continuous with the lamina dura. Radiographic appearance: The alveolar crest appears radiopaque and is typically located 1.5 to 2.5 mm below the cementoenamel junction.
- 13. Lamina dura: It isthe wall of the tooth socket that surrounds the root of the tooth. The lamina dura is made up of dense cortical bone. Radiographic appearance: On the dental radiograph the lamina dura appears as a dense radiopaque line that surround the root of the tooth.
- 14. Periodontal ligament space: Itis the space between the root of the tooth and the lamina dura. Radiographic appearance: It appears as a thin radiolucent line around the root of the tooth. In the healthy periodontium, the PDL space appears as a continuous radiolucent line of uniform thickness.
- 16. The periodontal ligamentspace appears as a thin radiolucent line around the roots of the tooth
- 17.
- 18. Maxilla Incisor region Radiolucent anatomicallandmarks :- Incisive foramen Median palatal suture Nasal cavity Superior foramina of the Nasopalatine canal Lateral fossa
- 19. Radiopaque anatomical landmarks:- Nasal septum Floor of nasal cavity Anterior nasal spine Inferior nasal conchae
- 20. On a maxillaryperiapical radiograph the incisive foramen appears as a small ovoid or round radiolucent area located between the roots of the maxillary central incisors
- 21. Superior foramina ofthe Nasopalatine canal appear as two small rounded radiolucencies located superior to the apices of the maxillary central incisors
- 22. Median palatine sutureappears as a thin radiolucent line between the maxillary central incisors. It’s bounded on both sides by dense radiopaque cortical bone.
- 23. on the maxillaryperiapical radiograph the lateral fossa appears as a radiolucent area between the maxillary canine and lateral incisor
- 24. The nasal cavityappears as a large radiolucent area above the upper incisors
- 25. The anterior nasalseptum appear as a vertical radiopaque partition divides the nasal cavity
- 26. The floor ofthe nasal cavity appears as a dense radiopaque band above the maxillary incisors
- 27. The anterior nasalspine appears as a V-shaped radiopaque area located at the intersection of the floor of the nasal cavity and nasal septum.
- 28. The inferior nasalconchae appear as a diffuse radiopaque mass or projection within the nasal cavity.
- 29. Canine region Radiolucent anatomicallandmarks :- Nasolacrimal duct Nasal cavity Maxillary sinus Lateral fossa
- 30. Radiopaque anatomical landmarks:- (InvertedY shape) Lateral wall of nasal fossa Anterior border of maxillary sinus Floor of maxillary sinus
- 31. The inverted Y-shapedappear as a radiopaque upside-down Y
- 32. Premolar region Radiolucent anatomicallandmarks :- Maxillary sinus Nutrient canals within the maxillary sinus Radiopaque anatomical landmarks:- Septa within the maxillary sinus Borders of maxillary sinus
- 33. Molar region Radiolucent anatomicallandmarks :- Maxillary sinus Nutrient canals within the maxillary sinus
- 34. Radiopaque anatomical landmarks:- Septa within the maxillary sinus Borders of maxillary sinus Maxillary tuberosity Hamular process Zygomatic process of maxilla Zygoma Coronoid process of the mandible
- 35. The maxillary sinusappears as a radiolucent area located above the apices of the maxillary premolars and molars. The floor of maxillary sinus is composed of dense cortical bone and appears as a radiopaque line.
- 36. the septa appearas radiopaque lines within the maxillary sinus.
- 37. Nutrient Canals withthe maxillary sinus: On a maxillary periapical radiograph nutrient canals appear as a narrow radiolucent band bounded by two thin radiopaque lines.
- 38. Nutrient canals appearas narrow radiolucent lines
- 39. The maxillary tuberosityappears as a radiopaque bulge distal to the third molar region
- 40. Hamular process:- smallhook- like projection of bone located posterior to the maxillary tuberosity The radiographic appearance of the hamulus varies in length, shape, and width.
- 41. Zygomatic process ofthe maxilla: The Zygomatic process of the maxilla is a bony projection of the maxilla that articulates with the zygoma or malar bone. The Zygomatic process of maxilla is composed of dense cortical bone.
- 42. The Zygomatic processof the maxilla appears as U- shaped radiopacity superior to the maxillary molars
- 43. Zygoma The zygoma orcheek bone (also referred to as the malar or Zygomatic bone) articulates with the Zygomatic process of the maxilla. The zygoma is composed of dense cortical bone.
- 44. The zygoma appearsas a diffuse radiopaque band that extend distally from the Zygomatic process of the maxilla
- 45. The Coronoid processappears as a triangle radiopaque superimposed over, or inferior to, the maxillary tuberosity region.
- 46. Mandible Anterior region Radiolucent anatomicallandmarks:- Nutrient canals Lingual foramen Mental fossa
- 47. Radiopaque anatomical landmarks:- Mentalridge Genial tubercle Inferior border of the mandible
- 48. Premolar region Radiolucent anatomicallandmarks:- Metal foramen Mandibular canal Radiopaque anatomical landmarks:- Mylohyoid ridge
- 49. Molar region Radiolucent anatomicallandmarks:- Mandibular canal Physiological thinning of bone Submandibular fossa
- 50. Radiopaque anatomical landmarks:- External oblique ridge Internal oblique ridge Borders of mandibular canal Inferior border of the mandible
- 51. Lingual foramen:- smallradiolucent dot inferior to the mandibular incisors and is surrounded by the genial tubercles, which appear as a radiopaque ring.
- 52. Genial tubercles: The genialtubercles are tiny bumps of bone that serve as attachment of the genioglossus and geniohyoid muscles. The genial tubercles are located on the lingual aspect of the mandible.
- 53. The genial tuberclesappear as a ring shaped radiopacity below the apices of the mandibular incisors
- 54. Nutrient canals: They aretube like passageways through bone that contain nerves and blood vessels that supply the teeth. Inter-dental nutrient canals are most often seen in the anterior mandible, a region that typically has thin bone. Radiographically, nutrient canals are readily seen in areas of thin bone. In edentulous mandible, nutrient canals may be more prominent.
- 55. Nutrient canals appearas thin vertical radiolucent lines
- 56. Mental ridge: It isa linear prominence of cortical bone located in the external surface of the anterior portion of the mandible. The mental ridge extends from the premolar region to the midline and slopes slightly upwards. Mental fossa:- Depressed area of bone located on the external surface of the anterior mandible above the mental ridge. The radiographic appearance of the mental fossa varies and is determined by the thickness of the bone in the anterior region of the mandible.
- 57. Mental ridge appearsas a thick radiopaque band that extends from the premolar region to the incisors region.
- 58. The mental fossaappears as a radiolucent area above the mental ridge
- 59. Mental foramen: It isan opening or hole in bone located on the external surface of the mandible in the region of the mandibular premolars. Radiographic appearance: on a mandibular periapical radiograph the mental foramen appears as a small ovoid or round radiolucent area located in the apical region of the mandibular premolars.
- 60. The mental foramenappears as a small ovoid or round radiolucent area located in the apical region of the mandibular premolars.
- 61. Mylohyoid ridge: It isa linear prominent of bone located on the internal surface of the mandible. The ridge extends from the molar region downward and forward toward the lower border on mandibular symphysis. The Mylohyoid ridge serves as an attachment site of a muscle of the same name.
- 62. The Mylohyoid ridgeappears as a dense radiopaque band that extends downward and forward from the molar region.
- 63. External oblique ridge: Theexternal oblique ridge (also known as the external oblique line) is linear prominence of bone located on the external surface of the body of the mandible. The anterior border of the ramus ends in the external oblique ridge. The external oblique ridge typically ends in the mandibular third molar region.
- 64. The external obliqueridge appears as a radiopaque band extending downward and forward from the anterior border of the ramus of the mandible.
- 65. Depending on theradiographic technique used (bisecting angle vs paralleling); the internal and external oblique ridges may be superimposed on one another. When the ridges appear separate, the superior radiopaque band is the external oblique ridge, and the inferior oblique radiopaque is the internal oblique ridge.
- 66. Mandibular canal: The mandibularcanal is a tube- like passage-way through bone that travels the length of the mandible. The mandibular canal extends from the mandibular foramen to the mental foramen and houses the inferior alveolar nerve and blood vessels.
- 67. Radiolucent band outlinedby two thin radiopaque lines It appears below or superimposed over the apices of the mandibular teeth.
- 70. Submandibular fossa: The Submandibularfossa (also known as the mandibular fossa or submaxillary fossa) is scooped-out depression area of bone located on the internal surface of the mandible inferior to the Mylohyoid ridge. The Submandibular salivary gland is found in the Submandibular fossa.
- 71. The Submandibular fossaappears as a radiolucent area in the molar region below the Mylohyoid ridge.