1. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. Chapter 27 Normal Anatomy: Intraoral Images

2. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 2 Dental Radiography  Questions  What is the difference between cortical and cancellous bone?  What normal anatomic landmarks of the maxilla and mandible are apparent on dental radiographs?  What is the radiographic appearance of tooth anatomy?

3. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 3 Dental Radiography  Chapter 27 Reading  Iannucci & Howerton (pp. 325-344)

4. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 4 Dental Radiography  Chapter 27 Outline  Normal Anatomy: Intraoral Films  Definitions of general terms  Normal anatomic landmarks  Normal tooth anatomy

5. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 5 Introduction  Iannucci & Howerton (pp. 326)  Purpose  To review the normal anatomy of the maxilla and mandible as viewed on the skull  To describe the normal anatomic landmarks seen on intraoral radiographs

6. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 6 Definitions of General Terms  Types of bone  Prominences of bone  Spaces and depressions in bone  Miscellaneous terms

7. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 7 Types of Bone  Iannucci & Howerton (pp. 326-327) (Figs. 27-1 through 27-3)  Cortical bone  The dense outer layer of bone  Appears radiopaque on a radiograph  Cancellous bone  The soft, spongy bone located between two layers of dense cortical bone  Appears primarily radiolucent Trabeculae appear radiopaque, marrow spaces appear radiolucent Trabeculae appear radiopaque, marrow spaces appear radiolucent

8. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 8 Prominences of Bone  Iannucci & Howerton (pp. 326-328) (Figs. 27-4 through 27-8)  Process: marked prominence or projection  Ridge: linear prominence or projection  Spine: sharp, thornlike projection  Tubercle: small bump or nodule  Tuberosity: rounded prominence

9. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 9 Spaces and Depressions in Bone  Iannucci & Howerton (pp. 328-330) (Figs. 27-9, 27-10)  Canal – tubelike passageway through bone that contains nerves and blood vessels  Foramen – opening or hole that permits the passage of nerves and blood vessels  Fossa – broad, shallow, scooped-out, or depressed area  Sinus – hollow space, cavity, or recess

10. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 10 Miscellaneous Terms  Iannucci & Howerton (pp. 327-328) (Fig. 27-11)  Septum  A bony wall or partition that divides two spaces or cavities  Radiopaque  Suture  An immovable joint representing a line of union between adjoining bones of the skull  A thin radiolucent line

11. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 11 Normal Anatomic Landmarks  Iannucci & Howerton (pp. 328)  Bony landmarks of the maxilla  Bony landmarks of the mandible

12. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 12 Bony Landmarks of the Maxilla  Iannucci & Howerton (pp. 328-329) (Fig. 27-12)  The upper jaw is composed of two paired bones, the maxillae.  The paired maxillae meet at the midline of the face.  Forms the  Floor of the orbit of the eye  Sides and floor of the nasal cavities  Hard palate

13. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 13 Bony Landmarks of the Maxilla  Incisive foramen  Superior foramina of the incisive canal  Median palatal suture  Lateral fossa  Nasal cavity  Nasal septum  Floor of the nasal cavity  Anterior nasal spine

14. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 14 Bony Landmarks of the Maxilla  Inferior nasal conchae  Maxillary sinus  Septa within the maxillary sinus  Nutrient canals within the maxillary sinus  Inverted Y  Maxillary tuberosity  Hamulus  Zygomatic process of the maxilla  Zygoma

15. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 15 Incisive Foramen (Nasopalatine Foramen)  Iannucci & Howerton (pp. 329-330) (Fig. 27-13)  Description  An opening or hole in bone that is located at the midline of the anterior portion of the hard palate directly posterior to the maxillary central incisors  Appearance  A small ovoid or round radiolucent area located between the roots of the maxillary central incisors

16. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 16 Superior Foramina of the Incisive Canal  Iannucci & Howerton (pp. 329-330) (Fig. 27-14)  Description  Two tiny openings or holes in bone that are located on the floor of the nasal cavity  Join together to form the incisive canal  Appearance  Two small round radiolucencies located superior to the apices of the maxillary central incisors

17. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 17 Median Palatal Suture  Iannucci & Howerton (p. 330) (Fig. 27-15)  Description  The immovable joint between the two palatine processes of the maxilla  Appearance  A thin radiolucent line between the maxillary central incisors

18. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 18 Lateral Fossa  Iannucci & Howerton (pp. 330-331) (Fig. 27-16)  Description  A smooth, depressed area of the maxilla located just inferior and medial to the infraorbital foramen between the canine and lateral incisors  Appearance  A radiolucent area between the maxillary canine and lateral incisors

19. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 19 Nasal Cavity  Iannucci & Howerton (p. 331) (Fig. 27-17)  Description  A pear-shaped compartment of bone located superior to the maxilla The inferior portion is formed by the palatal processes of the maxilla and the horizontal portions of the palatine bones. The inferior portion is formed by the palatal processes of the maxilla and the horizontal portions of the palatine bones.  Appearance  A large radiolucent area above the maxillary incisors

20. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 20 Nasal Septum  Iannucci & Howerton (p. 331) (Fig. 27-18)  Description  A vertical bony wall or partition that divides the nasal cavity into the right and left nasal fossae  Formed by the vomer and a portion of the ethmoid bone and cartilage  Appearance  A vertical radiopaque partition that divides the nasal cavity

21. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 21 Floor of the Nasal Cavity  Iannucci & Howerton (p. 332) (Fig. 27-19)  Description  A bony wall formed by the palatal processes of the maxilla and the horizontal portions of the palatine bones  Appearance  A dense radiopaque band of bone above the maxillary incisors

22. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 22 Anterior Nasal Spine  Iannucci & Howerton (p. 332) (Fig. 27-20)  Description  A sharp projection of the maxilla located at the anterior and inferior portion of the nasal cavity  Appearance  A V-shaped radiopaque area located at the intersection of the floor of the nasal cavity and the nasal septum

23. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 23 Inferior Nasal Conchae  Iannucci & Howerton (pp. 332-333) (Fig. 27-21)  Description  Wafer-thin, curved plates of bone that extend from the lateral walls of the nasal cavity  Conchae means shell-shaped or scroll-shaped.  Appearance  A diffuse radiopaque mass or projection within the nasal cavity

24. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 24 Maxillary Sinus  Iannucci & Howerton (pp. 332-333) (Figs. 27-22, 27-23)  Description  Paired cavities or compartments of bone located within the maxilla  Located above the maxillary premolar and molar teeth  Appearance  A radiolucent area located above the apices of the maxillary premolars and molars

25. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 25 Septa within the Maxillary Sinus  Iannucci & Howerton (pp. 332-333) (Figs. 27-24, 27-25)  Description  Bony walls or partitions that appear to divide the maxillary sinus into compartments  Appearance  Radiopaque lines within the maxillary sinus  Presence and number vary depending on the anatomy of the individual.

26. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 26 Nutrient Canals within the Maxillary Sinus  Iannucci & Howerton (p. 334) (Fig. 27-26)  Description  Tiny, tubelike passageways through bone that contain blood vessels and nerves  Appearance  A narrow radiolucent band bounded by two thin radiopaque lines

27. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 27 Inverted Y  Iannucci & Howerton (p. 334) (Fig. 27-27)  Description  The intersection of the maxillary sinus and the nasal cavity  Appearance  A radiopaque upside-down Y formed by the intersection of the lateral wall of the nasal fossa and the anterior border of the maxillary sinus  Located above the maxillary canine

28. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 28 Maxillary Tuberosity  Iannucci & Howerton (p. 334) (Fig. 27-28)  Description  A rounded prominence of bone that extends posterior to the third molar region  Appearance  A radiopaque bulge distal to the third molar region

29. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 29 Hamulus  Iannucci & Howerton (pp. 334-335) (Fig. 27-29)  Description  A small hooklike projection of bone extending from the medial pterygoid plate of the sphenoid bone  Appearance  A radiopaque hooklike projection posterior to the maxillary tuberosity area

30. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 30 Zygomatic Process of the Maxilla  Iannucci & Howerton (pp. 334-335) (Figs. 27-30, 27-31)  Description  A bony projection of the maxilla that articulates with the zygoma or malar (cheek) bone  Appearance  A J- or U-shaped radiopacity located superior to the maxillary first molar region

31. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 31 Zygoma  Iannucci & Howerton (pp. 335-336) (Figs. 27-32, 27-33)  Description  Articulates with the zygomatic process of the maxilla  Appearance  A diffuse, radiopaque band extending posteriorly from the zygomatic process of the maxilla

32. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 32 Bony Landmarks of the Mandible  Iannucci & Howerton (pp. 335-336) (Fig. 27-34)  The largest and strongest bone of the face  Divided into three main parts  Ramus Vertical portion found posterior to the third molar Vertical portion found posterior to the third molar  Body Horizontal U-shaped portion from ramus to ramus Horizontal U-shaped portion from ramus to ramus  Alveolar process Encases and supports the teeth Encases and supports the teeth

33. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 33 Bony Landmarks of the Mandible  Iannucci & Howerton (pp. 335-340)  Genial tubercles  Lingual foramen  Nutrient canals  Mental ridge  Mental fossa  Mental foramen

34. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 34 Bony Landmarks of the Mandible  Mylohyoid ridge  Mandibular canal  Internal oblique ridge  External oblique ridge  Submandibular fossa  Coronoid process

35. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 35 Genial Tubercles  Iannucci & Howerton (pp. 335-336) (Fig. 27-35)  Description  Tiny bumps of bone on the lingual aspect of the mandible  Attachment sites for genioglossus and geniohyoid muscles  Appearance  A ring-shaped radiopacity below the apices of the mandibular incisors

36. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 36 Lingual Foramen  Iannucci & Howerton (p. 336) (Fig. 27-36)  Description  A tiny opening or hole in bone located on the internal surface of the mandible  Appearance  A small radiolucent dot inferior to the apices of the mandibular incisors

37. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 37 Nutrient Canals  Iannucci & Howerton (pp. 336-337) (Fig. 27-37)  Description  Tubelike passageways through bone containing nerves and blood vessels that supply the teeth  Most often seen in anterior mandible  Appearance  Vertical radiolucent lines readily seen in areas of thin bone

38. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 38 Mental Ridge  Iannucci & Howerton (p. 337) (Fig. 27-38)  Description  A linear prominence of cortical bone located on the external surface of the anterior portion of the mandible  Appearance  A thick radiopaque band that extends from the premolar region to the incisor region  Often appears superimposed over the mandibular anterior teeth

39. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 39 Mental Fossa  Iannucci & Howerton (pp. 337-338) (Fig. 27-39)  Description  A scooped-out, depressed area of bone located on the external surface of the anterior mandible  Appearance  A radiolucent area above the mental ridge

40. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 40 Mental Foramen  Iannucci & Howerton (pp. 337-338) (Figs. 27-40)  Description  An opening or hole in bone located on the external surface of the mandible in the region of the mandibular premolars  Appearance  A small ovoid or round radiolucent area located in the apical region of the mandibular premolars  Frequently misdiagnosed as a periapical lesion

41. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 41 Mylohyoid Ridge  Iannucci & Howerton (pp. 337-338) (Fig. 27-41)  Description  A linear prominence of bone located on the internal surface of the mandible  Appearance  A dense radiopaque band that extends downward and forward from the molar region

42. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 42 Mandibular Canal  Iannucci & Howerton (p. 338) (Fig. 27-42)  Description  A tubelike passageway through bone that travels the length of the mandible  Houses the inferior alveolar nerve and blood vessels  Appearance  A radiolucent band outlined by two thin radiopaque lines that represent the cortical walls of the canal

43. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 43 Internal Oblique Ridge  Iannucci & Howerton (pp. 338-339) (Figs. 27-43)  Description  A linear prominence of bone located on the internal surface of the mandible the ramus  Appearance  A radiopaque band that extends downward and forward from the ramus  When both appear, the external oblique ridge is superior to the internal oblique ridge.

44. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 44 External Oblique Ridge  Iannucci & Howerton (p. 339) (Figs. 27-44, 27-45)  Description  A linear prominence of bone located on the external surface of the body of the mandible  Appearance  A radiopaque band extending downward and forward from the anterior border of the ramus of the mandible

45. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 45 Submandibular Fossa  Iannucci & Howerton (p. 339) (Fig. 27-46)  Description  A scooped-out, depressed area of bone located on the internal surface of the mandible inferior to the mylohyoid ridge  Appearance  A radiolucent area in the molar region below the mylohyoid ridge

46. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 46 Coronoid Process  Iannucci & Howerton (pp. 339-340) (Fig. 27-47)  Description  A marked prominence of bone on the anterior ramus of the mandible  Radiographic appearance  A triangular radiopacity superimposed over, or inferior to, the maxillary tuberosity region

47. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 47 Normal Tooth Anatomy  Tooth structure  Supporting structures

48. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 48 Tooth Structure  Iannucci & Howerton (p. 340) (Figs. 27-48, 27-49, 27-50)  Enamel – the outermost radiopaque layer of the crown of a tooth  Dentin – comprises most of the tooth structure, not as radiopaque as enamel  Dentinoenamel junction – the junction between dentin and enamel  Pulp Cavity – a pulp chamber and pulp canals

49. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 49 Supporting Structures  Iannucci & Howerton (pp. 340-341) (Figs. 27-51)  Anatomy of alveolar bone  Lamina dura  Alveolar crest  Periodontal ligament space  Shape and density of alveolar bone  Anterior regions  Posterior regions

50. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 50 Anatomy of Alveolar Bone  Iannucci & Howerton (pp. 341) (Fig. 27-52)  Anatomic landmarks of the alveolar process include the lamina dura, alveolar crest, and periodontal ligament space.

51. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 51 Lamina Dura  Iannucci & Howerton (p. 341) (Fig. 27-53)  Description  The wall of the tooth socket  Made of dense cortical bone  Appearance  A dense radiopaque line that surrounds the root of a tooth

52. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 52 Alveolar Crest  Iannucci & Howerton (pp. 341-342) (Fig. 27-54)  Description  The most coronal portion of the alveolar bone found between teeth  Appearance  Appears radiopaque, typically 1.5 to 2.0 mm. below the cementoenamel junction

53. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 53 Periodontal Ligament Space  Iannucci & Howerton (pp. 341-342) (Fig. 27-55)  Description  The space between the root of the tooth and the lamina dura  Appearance  A thin radiolucent line around the root of a tooth

54. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 54 Shape and Density of Alveolar Bone  Iannucci & Howerton (pp. 341-342) (Fig. 27-56)  Anterior regions  Normal alveolar crest appears pointed and sharp between the teeth.  The alveolar crest appears as a dense radiopaque line in the anterior region.

55. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 55 Shape and Density of Alveolar Bone  Iannucci & Howerton (p. 342) (Fig. 27-57)  Posterior regions  Normal alveolar crest appears flat and smooth between the teeth.  The alveolar crest appears less dense and less radiopaque than the alveolar crest seen in the anterior region.