1. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 1 Extraoral Imaging

2. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 2 X-ray Unit A standard intraoral x-ray machine may be used for a variety of extraoral projections. Special head positioning and beam alignment devices can be added. Special head positioning and beam alignment devices can be added. The panoramic tubehead is used in conjunction with a special extension arm and a device known as a cephalostat or craniostat. Some panoramic x-ray units can be used for additional extraoral projections Some panoramic x-ray units can be used for additional extraoral projections

3. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 3 Film Most extraoral exposures are made with screen film placed in a cassette with intensifying screens. Screen film is sensitive to the light emitted from intensifying screens. Screen film is sensitive to the light emitted from intensifying screens. An occlusal film is a nonscreen film that may be used for some extraoral radiographs.

4. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 4 Intensifying Screens A device that converts x-ray energy into visible light; the light, in turn, exposes the screen film The screen film must be compatible with the light emitted from the screen. The screen film must be compatible with the light emitted from the screen.

5. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 5 Cassette Purpose is to hold the receptor in tight contact with the intensifying screen and to protect the film from exposure to light. Must be labeled to orient the finished image. The front side is typically constructed of plastic, back side is made of metal.

6. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 6Grid A device used to reduce the amount of scatter radiation that reached an extraoral film during exposure A series of thin lead strips embedded in a material that permits passage of the x-ray beam A series of thin lead strips embedded in a material that permits passage of the x-ray beam The grid is placed between the patient’s head and the film. During exposure, the grid permits passage of the x-ray beam between the lead strips. During exposure, the grid permits passage of the x-ray beam between the lead strips. Scatter radiation is absorbed by the lead strips and does not reach the surface of the film. Scatter radiation is absorbed by the lead strips and does not reach the surface of the film.

7. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 7 GRID

8. 8 Step-by-step Procedures Infection control procedures must be complete before exposing an extraoral receptor. If an extraoral unit with cephalostat is used, the ear rods must be wiped with disinfectant between patients. If an extraoral unit with cephalostat is used, the ear rods must be wiped with disinfectant between patients.

9. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 9 Patient Preparation Explain the radiographic procedure to the patient. Place a lead apron without a thyroid collar over the patient and secure it. Remove all objects from the head and neck region that may interfere with exposure.

10. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 10 Patient Positioning Varies with each extraoral radiographic projection

11. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 11 Extraoral Projection Techniques Lateral Jaw Imaging Skull Imaging Temporomandibular Joint Imaging

12. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 12 Lateral Jaw Radiography Used to examine the posterior region of the mandible Includes Includes Body of the mandible projection Ramus of the mandible projection

13. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 13 Body of the Mandible Purpose To evaluate impacted teeth, fractures, and lesions located in the body of the mandible To evaluate impacted teeth, fractures, and lesions located in the body of the mandible Receptor placement Flat against cheek Flat against cheek Centered over body of mandible Centered over body of mandible Head position Tipped 15 degrees toward side being imaged Tipped 15 degrees toward side being imaged Chin extended and elevated Chin extended and elevated

14. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 14 Body of the Mandible Beam alignment Below inferior border of mandible, vertical angulation -15 to -20 degrees Below inferior border of mandible, vertical angulation -15 to -20 degrees Perpendicular to horizontal plane of cassette Perpendicular to horizontal plane of cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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16. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 16 Body of the Mandible Projection

17. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 17 Ramus of the Mandible Purpose To evaluate impacted third molars, large lesions, and fractures that extend into the ramus of the mandible To evaluate impacted third molars, large lesions, and fractures that extend into the ramus of the mandible Receptor placement Flat against cheek, centered over ramus of mandible Flat against cheek, centered over ramus of mandible Head position Tipped 15 degrees toward side being imaged Tipped 15 degrees toward side being imaged Chin extended and elevated Chin extended and elevated

18. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 18 Ramus of the Mandible Beam alignment Posterior to third molar area Posterior to third molar area Vertical angulation -15 to -20 degrees Vertical angulation -15 to -20 degrees Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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20. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 20 Ramus of the Mandible

21. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 21 Skull Imaging Used to examine the bones of the face and skull Used most often in oral surgery and orthodontics Used most often in oral surgery and orthodontics Includes: Includes: Lateral cephalometric projection Posteroanterior projection Waters projection Submentovertex projection Reverse Towne projection

22. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 22 Lateral Cephalometric Projection Purpose To evaluate facial growth and development, trauma, and disease and developmental abnormalities; used commonly in orthodontics To evaluate facial growth and development, trauma, and disease and developmental abnormalities; used commonly in orthodontics Receptor placement Cassette perpendicular to the floor Cassette perpendicular to the floor Long axis of cassette horizontal Long axis of cassette horizontal

23. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 23 Lateral Cephalometric Projection Head position Left side of patient’s head near cassette Left side of patient’s head near cassette Midsagittal plane perpendicular to the floor Midsagittal plane perpendicular to the floor Frankfort plane parallel to the floor Frankfort plane parallel to the floor Beam alignment Central ray perpendicular to the cassette Central ray perpendicular to the cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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25. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 25 Lateral Cephalometric

26. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 26 Posteroanterior Projection Purpose To evaluate facial growth and development, trauma, and disease and developmental abnormalities To evaluate facial growth and development, trauma, and disease and developmental abnormalities Receptor placement Cassette perpendicular to the floor Cassette perpendicular to the floor Long axis of cassette horizontal Long axis of cassette horizontal

27. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 27 Posteroanterior Projection Head position Forehead and nose touch cassette Forehead and nose touch cassette Midsagittal plane perpendicular to the floor Midsagittal plane perpendicular to the floor Frankfort plane parallel to the floor Frankfort plane parallel to the floor Beam alignment Central ray perpendicular to the cassette Central ray perpendicular to the cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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29. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 29 Posteroanterior Projection

30. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 30 Waters Projection Purpose To evaluate the maxillary sinus area To evaluate the maxillary sinus area Receptor placement Cassette perpendicular to the floor Cassette perpendicular to the floor Long axis of the cassette is vertical Long axis of the cassette is vertical Head position Chin touches cassette Chin touches cassette Tip of nose ½ -1 inch from cassette Tip of nose ½ -1 inch from cassette Midsagittal plane perpendicular to the floor Midsagittal plane perpendicular to the floor

31. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 31 Waters Projection Beam alignment Central ray through center of the head and perpendicular to the cassette Central ray through center of the head and perpendicular to the cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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33. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 33 Waters Projection

34. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 34 Submentovertex Projection Purpose To identify the position of the condyles, demonstrate the base of the skull, and evaluate fractures of the zygomatic arch To identify the position of the condyles, demonstrate the base of the skull, and evaluate fractures of the zygomatic arch Receptor placement Cassette perpendicular to the floor Cassette perpendicular to the floor Long axis of the cassette is vertical Long axis of the cassette is vertical

35. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 35 Submentovertex Projection Head position Head tipped back Head tipped back Top of head touches cassette Top of head touches cassette Midsagittal plane and Frankfort plane perpendicular to the floor Midsagittal plane and Frankfort plane perpendicular to the floor Beam alignment Central ray through center of the head and perpendicular to the cassette Central ray through center of the head and perpendicular to the cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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37. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 37 Submentovertex Projection

38. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 38 Reverse Towne Projection Purpose To identify fractures of the condylar neck and ramus area To identify fractures of the condylar neck and ramus area Receptor placement Cassette perpendicular to the floor Cassette perpendicular to the floor Long axis of the cassette is vertical Long axis of the cassette is vertical

39. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 39 Reverse Towne Projection Head position Head tipped down Head tipped down Mouth open wide as possible Mouth open wide as possible Top of forehead touches cassette Top of forehead touches cassette Midsagittal plane perpendicular to the floor Midsagittal plane perpendicular to the floor Beam alignment Central ray through center of the head and perpendicular to the cassette Central ray through center of the head and perpendicular to the cassette Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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41. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 41 Reverse Towne Projection

42. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 42 Temporomandibular Joint Imaging The joint includes the temporal bone and the mandible. The glenoid fossa and articular eminence of the temporal bone, the condyle of the mandible, and the articular disk between the bones comprise the TMJ. The glenoid fossa and articular eminence of the temporal bone, the condyle of the mandible, and the articular disk between the bones comprise the TMJ. Includes Includes Transcranial projection Temporomandibular joint tomography

43. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 43 Transcranial Projection (Lindblom Technique) Purpose To evaluate the superior surface of the condyle and the articular eminence To evaluate the superior surface of the condyle and the articular eminence Receptor placement Flat against patient’s ear Flat against patient’s ear Centered over TMJ Centered over TMJ

44. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 44 Transcranial Projection Head position Midsagittal plane perpendicular to the floor and parallel with the cassette Midsagittal plane perpendicular to the floor and parallel with the cassette Beam alignment 2 inches above and 0.5 inch behind the ear canal opening 2 inches above and 0.5 inch behind the ear canal opening Vertical angulation +25 degrees, horizontal angulation forward 20 degrees Vertical angulation +25 degrees, horizontal angulation forward 20 degrees Exposure factors Vary with the receptor, intensifying screens, and equipment used Vary with the receptor, intensifying screens, and equipment used

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46. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 46 Transcranial projection for TMJ

47. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 47 Temporomandibular Joint Tomography Used to examine the temporomandibular joint The location of the rotational point determines what plane of the head of the TM joint will be imaged. The location of the rotational point determines what plane of the head of the TM joint will be imaged.

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49. Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc. 49 TMJ Tomography