©2013 Delmar, Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in

©2013 Delmar, Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part.

Extraoral and Digital Radiography

Chapter 23


Extraoral Radiographs

• Panoramic– Common in general and specialty offices

• Cephalometric– Common with orthodontists

• Digital– Becoming standard– Easier for staff


Panoramic Radiography

• Tomography– One layer shown

• Rotational centers– Tubehead– Cassette

• Focal trough– Image layer or sharpness


Panoramic Unit

• Exposure controls• Head positioner• X-ray tubehead• Cassette holder

© Cengage Learning 2013


Panoramic Techniques

• Lead apron without thyroid collar

• Bite block barrier

• Cassette preparation in dark room

• Explanation of procedure– Patient must be still


Common Errors

• Preparation– Ghost image– Lead apron artifact

• Positioning– Too far forward or too

far back– Patient’s head tilted

down or up– Patient’s tongue not

against roof of mouth– Patient not standing

up straight


Dental Check

• What can be visualized on a panoramic radiograph?– Entire dentition, nasal and orbital areas,

alveolar bone, carious lesions, fractures, cysts, tumors, malocclusion, maxilla, mandible, sinuses, unerupted teeth, dental appliances, restorations, periodontal disease, and TMJ


Cephalometric Radiographs

• Patient’s skeletal structure and profile

• Orthodontists mainly use

• Lateral jaw radiograph• Transcranial TMJ

radiograph



Radiographic Interpretation

• Terminology– Anatomical landmarks– Radiopaque– Radiolucent– Diagnosis– Interpretation– Superimposition


Tooth and Surrounding Tissues



Mandibular Landmarks



Maxillary Landmarks



Imaging Systems and Digital Radiology

• Computed tomography (CT)

• Magnetic resonance imaging (MRI)

• Digital radiography– New technology becoming common– Dental film not needed


Digital Radiography

• Analog image– No limits

• Intraoral and extraoral possible

• Pixels and gray scale


Digital Radiography

• Direct digital imaging– X-ray machine– Sensor– Computer monitor and software


Digital Radiology

• Indirect digital imaging– Converts traditional X-rays to images– Scanner– Computer monitor and software

• Storage phosphor imaging


Advantages of Digital Radiology

• Less radiation to patient

• Quick results

• Image alterations possible

• Storage

• Darkroom, equipment, and solutions eliminated

• Data files can be attached


Disadvantages of Digital Radiology

• Initial expense

• Proficiency training

• Uncomfortable sensors

• System failures


3-Dimensional (3-D) Imaging in Dentistry

• Shows immediate 3D reconstruction of patient’s mouth, face, and jaw areas

• Lowest possible radiation levels

• “Cone beam” shaped to cover image in single scan


Uses and Benefits of 3-D Imaging

• Locate detailed anatomy

• Evaluate deformities• Locate pathology

– E.g., cysts, bone lesions

• Show miniscule detail• Determine bone

quality• Evaluate

temporomandibular disorders (TMD) and TMJ diagnosis


Patient Preparation

• Patient may stand or sit comfortably in open scanner

• Scans can be done in dental office

• Scans are quick– 8 to 20 seconds

• Information is processed in less than one minute and ready to be examined by dentist to discuss diagnosis with patient


Hand-Held Intraoral Radiography

• Battery-operated and portable

• Low radiation dose

• Digital control panel– Adult-Child– Anterior, posterior, and bitewings– Expose film, digital sensors, or phosphor

plates


Dental Check

• Discuss what makes digital imaging more efficient.– Is immediate – no processing involved – Patient can view at the same time as the

dentist– Can easily be e-mailed to third parties when

necessary

Documents

©2013 Delmar, Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in