Transcript ch29 Dent Rad-NC

Extraoral Radiography and Alternate Imaging
Modalities
Chapter 29
Objectives
 Define the key words.
 Describe the purpose and use of extraoral radiographs.
 List seven extraoral radiographs that contribute to the
treatment of dental patients.
 Explain the need for proper extraoral film handling.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Objectives
 Explain the role intensifying screens play in producing a
radiographic image.
 Match blue- and green-light sensitive film with the
appropriate intensifying screen.
 Explain the role of the extraoral film cassette.
 Describe how extraoral radiographs are labeled.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Objectives
 Explain the need for proper care and cleaning of cassettes and
intensifying screens.
 Explain the role grids play in extraoral radiography.
 Explain tomography and describe its role in oral health care.
 Explain cone beam computed tomography and describe its
role in oral health care.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Introduction
 Extraoral radiographs and alternate imaging modalities such
as computed tomography record large areas of the dental
arches, supporting facial structures, and skull using image
receptors that are positioned outside the mouth.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Introduction
 Knowing the types of extraoral radiographs and alternate
imaging modalities, understanding the conditions that most
likely benefit from each; and being able to recognize the
different images are valuable skills.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Introduction
 The dental assistant and/or hygienist may be asked to
educate the patient about the procedure or assist with
scheduling the patient’s appointment for the referral.
 Oral radiographers should be able to communicate
professionally with other health care professionals.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-1 A combination panoramic and cephalometric dental x-ray unit. (Courtesy of Planmeca.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Purpose and Use of
Extraoral Imaging Modalities
 Examine large areas of the dental arches and skull.
 Study growth and development of bone and teeth.
 Detect fractures and evaluate trauma.
 Detect pathological lesions and diseases of the jaws.
 Detect and evaluate impacted teeth.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Purpose and Use of
Extraoral Imaging Modalities
 Evaluate temporomandibular disorder (TMD).
 Plan treatment for dental implants and prosthetic appliances.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-2 Cephalometric radiograph produced with a filter placed between the tube and patient to remove some of the xrays to record outlines of the soft tissue profile.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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TABLE 29-1
Extraoral
Radiographs of the
Maxillofacial
Region
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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TABLE 29-1 (continued) Extraoral Radiographs of the Maxillofacial Region
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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TABLE 29-1 (continued) Extraoral Radiographs of the
Maxillofacial Region
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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TABLE 29-1 (continued) Extraoral Radiographs of the Maxillofacial Region
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Extraoral Image Receptors
 Traditional film
 Intensifying screens
 Cassettes
 Film identification
 Care of cassettes and intensifying screens
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-3 Loading film into a flexible cassette under safelight conditions.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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PROCEDURE 29-1
Loading an extraoral cassette
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-4 Loading a rigid cassette.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-5 Film is placed between the intensifying screens.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-6 Static electricity artifacts. Blank area on a panoramic film showing static electricity artifacts.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-7 Cross-section of cassette showing the effect of x-ray and fluorescent light on the film. X-ray A strikes a
crystal in the screen behind the film, producing light that then forms latent images in the silver halide crystal of the film. X-ray
B strikes a silver halide crystal in the film, forming a latent image. X-ray C strikes a crystal in the screen in front of the film,
producing light, which then forms latent images in the silver halide crystals of the film .
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-8 The back side of three rigid cassettes of various sizes.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-9 Film identification printer for imprinting permanent identification information on the
radiographic image.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-10 Grid used to absorb back scattered radiation is placed between the patient and the film to
absorb scattered x-rays to reduce film fog.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-11 Serial radiographs produced by tomography of the temporomandibular joint showing
the head of the condyle in the glenoid fossa with the mouth closed, in the at-rest position, and with the
mouth open.
(Courtesy of McCormack Dental X-ray Laboratory.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-12 A combination panoramic and TMJ tomography imaging dental x-ray unit. (Courtesy of
Planmeca.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-13 CT scanner.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Figure 29-14 Cone beam volumetric imaging machine. Designed for the oral health care practice, can
also produce panoramic radiographs.
(Courtesy of Gendex Dental Systems/Imaging Sciences Intl.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Figure 29-15 Image produced by CBCT and reconstructed software. Note the images produced from
different planes and the reconstructed 3D image of the teeth in the arches.
(Courtesy of Planmeca.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Review: Chapter Summary
 Extraoral radiographs image large areas of the head and facial
regions.
 Extraoral screen film is used with a pair of intensifying
screens housed in a light-tight cassette.
 Grids are devices used to absorb scatter radiation that would
fog the film and compromise image contrast.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Review: Chapter Summary
 Radiographs are produced with a stationary x-ray source an
image receptor.
 The practitioner must be skilled in interpreting images
obtained by CBCT.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Recall: Study Questions
 General
 Chapter Review
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Reflect: Case Study
 Consider the following patients and conditions. Which of the six
extraoral radiographs described in this chapter might be the best
recommendation for these cases?
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Reflect: Case Study
 (Note: Radiographs of the skull are difficult to interpret due
to the numerous structures that exist in a very small area.
These structures often appear superimposed over each other,
requiring multiple views to obtain a good diagnosis.
Therefore, in some of these cases, while there is usually a
best answer, there may be more than one correct answer.)
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Reflect: Case Study
1.
A 20-year-old patient presents with pain and swelling from
an impacted third molar. The patient can open only 10 mm.
No panoramic unit is available. What is an alternate
extraoral projection type that can be used to assess with
diagnosis for this patient?
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Reflect: Case Study
2.
A 13-year-old patient presents for an orthodontic
consultation. Occlusal (teeth) and facial disharmonies (soft
tissue relationships) need to be assessed prior to treatment
intervention.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Reflect: Case Study
A difficult extraction case presents with a severely decayed
maxillary molar. During the extraction procedure, the root
tip fractures and is possibly lost in the sinus cavity.
4. A medically compromised patient suffered a seizure and
fell. A fractured mandibular condyle is suspected.
3.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
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Reflect: Case Study
5.
A 69-year-old patient presents with a history of
degenerative joint disease that may be affecting the
temporal mandibular joint. An examination for the purpose
of diagnosing ankylosis (a stiffening of the TMJ) is planned.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Reflect: Case Study
6.
A patient presents for extraction of several badly decayed
teeth, following which the prosthodontist will construct a
maxillary full denture and a mandibular partial denture.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.
Relate: Laboratory Application
 Proceed to Chapter 29, Laboratory Application, to complete
this activity.
Essentials of Dental Radiography for Dental Assistants and Hygienists, Ninth Edition
Evelyn M. Thomson • Orlen N. Johnson
Copyright ©2012 by Pearson Education, Inc.
All rights reserved.