Technique Basics (Ch 16-24) Flashcards
Ch 16- Introduction to Radiographic Examinations Ch 17- Paralleling Technique Ch 18- Bisecting Technique Ch 19- Bite-wing Technique Ch 20- Exposure and Technique Errors Ch 21- Occlusal and Localization Techniques Ch 22- Panoramic Imaging Ch 23- Extraoral Imaging Ch 24- Imaging of Patients with Special Needs
What is an intraoral radiographic examination?
a radiographic inspection of the teeth and intraoral adjacent structures
What are intraoral receptors?
receptors placed inside the mouth to examine the teeth and supporting structures
What are the three types of intraoral radiographic examinations?
-periapical
-interproximal
-occlusal
What is the purpose of a periapical radiographic examination?
to examine the entire tooth and supporting bone
What is a periapical receptor?
the type of imaging receptor used for periapical radiographs
What are the two techniques that can be used for a periapical radiographic examination?
-paralleling technique
-bisecting technique
What is the purpose of an interproximal radiographic examination?
to examine the crowns of both the maxillary and mandibular teeth on a single image
What type of image receptor is used for an interproximal radiographic examination?
bite-wing receptor
What is a bite-wing receptor?
the type of imaging receptor used for bite-wing radiographs
What technique is used for an interproximal radiographic examination?
bite-wing technique
What is the purpose of an occlusal radiographic examination?
to examine large areas of the maxilla or mandible in one image
What type of image receptor is used for an occlusal radiographic examination?
occlusal receptor
What technique is used for an occlusal radiographic examination?
the occlusal technique
What is a full mouth series (FMX) of radiographs?
a series of intraoral dental radiographs that show all the tooth-bearing areas of the maxilla and mandible
What are considered tooth-bearing areas?
the regions of the maxilla and mandible where the 32 teeth of the human dentition are normally located
What are dentulous areas?
areas where teeth are present
What are edentulous areas?
areas where teeth are not present
How many radiographs are typically taken in a full mouth series for an adult with no missing teeth?
18 radiographs
List some general diagnostic criteria for intraoral radiographs.
-must display optimal density, contrast, definition, and detail
-must display the least amount of distortion possible
-must be of the same size and shape as the object being radiographed
-FMX must include all tooth-bearing areas, including dentulous and edentulous regions
-periapical images must show the entire crown and root of the teeth being examined, as well as 2-3mm beyond the apices
-bite-wing images must show open contacts or interproximal tooth surfaces that are not overlapped
When taking a periapical radiograph, how far below the apex of the tooth should be captured in the image?
2-3mm
What is an extraoral radiographic examination?
a radiographic inspection of large areas of the skull or jaws
What are extraoral receptors?
the type of imaging receptor used for extraoral radiographs
List some examples of extraoral radiographs.
-panoramic
-cephalometric
-transcranial
-tomographic
What does the term parallel mean?
moving or lying in the same plane, always separated by the same distance and not intersecting
What does the term intersecting mean?
to cut across or through
What does the term perpendicular mean?
intersecting at or forming a right angle
What is a right angle?
an angle of 90 degrees formed by two lines perpendicular to each other
What is the long axis of the tooth?
an imaginary line that divides the tooth longitudinally into two equal halves
What is the central ray?
the central portion of the primary beam of x-radiation
With the paralleling technique, how is the receptor placed intraorally in relation to the long axis of the tooth being radiographed?
parallel
With the paralleling technique, how is the central ray directed in relation to the receptor and the long axis of the tooth?
perpendicular
Is a beam alignment device necessary for the paralleling technique?
yes; the patient cannot hold the receptor
What is object-receptor distance?
the distance between the receptor and the object being radiographed
What is target-receptor distance?
the distance between the source of x-rays and the receptor
During the paralleling technique, in order to compensate for image magnification caused by an increased object-receptor distance, how should the target-receptor distance be influenced?
increased
What is a beam alignment device, and what is its purpose?
a device used to align the position-indicating device in relation to the tooth and receptor; helps to position the intraoral receptor and retain/stabilize the receptor during exposure and reduce the chances of movement
What are the three components of the Rinn XCP instruments?
-plastic bite block
-plastic aiming ring
-metal indicator arm
What is the color coding system used with the Rinn XCP instruments?
blue = anterior
yellow = posterior
red = bite-wing
How do beam alignment devices help to prevent a patient’s exposure to excess radiation?
by holding the receptor in place and stabilizing it during exposure in order to prevent movement, and therefore, the need for a retake of the radiograph
What is an exposure sequence?
a definite order for periapical receptor placement and exposure that must be followed in the placement and exposure of intraoral radiographs
When using the paralleling technique, what is required to be captured when radiographing a maxillary canine using an anterior periapical receptor?
-the entire crown and root of the canine
-the interproximal alveolar bone and mesial contact of the canine
When using the paralleling technique, what is required to be captured when radiographing maxillary incisors using an anterior periapical receptor?
-the entire crown and root of the one lateral and one central incisor
-the interproximal alveolar bone between the central and lateral and the surrounding regions of bone
-the mesial and distal contact areas of the central and lateral incisor
-the mesial contact of the adjacent central incisor
-the mesial contact of the adjacent canine
When using the paralleling technique, what is required to be captured when radiographing mandibular incisors using an anterior periapical receptor?
-the entire crowns and roots of four mandibular incisors
-contacts between all teeth
When using the paralleling technique, what is required to be captured when radiographing mandibular canines using an anterior periapical receptor?
-the entire crown and root of the canine
-the interproximal alveolar bone
-the mesial and distal contacts
When using the paralleling technique, what is required to be captured when radiographing maxillary premolars using a posterior periapical receptor?
-the entire crowns and roots of the first and second premolars
-the alveolar crests and surrounding bone
-the contact areas
-the distal contact of the maxillary canine
When using the paralleling technique, what is required to be captured when radiographing maxillary molarsusing a posterior periapical receptor?
-the entire crowns and roots of the first, second, and third molars
-the alveolar crests and surrounding bone
-the contact areas
-the tuberosity region
-the distal contact of the maxillary second premolar
When using the paralleling technique, what is required to be captured when radiographing mandibular premolars using a posterior periapical receptor?
-the entire crowns and roots of the first and second premolars
-the alveolar crests and surrounding bone
-the contact areas
-the distal contact of the mandibular canine
When using the paralleling technique, what is required to be captured when radiographing mandibular molars using a posterior periapical receptor?
-the entire crowns and roots of the first, second, and third molars
-the alveolar crests and surrounding bone
-the contact areas
-the distal contact of the mandibular second premolar
If a patient has a shallow palate and the paralleling technique cannot be properly accomplished, how should the vertical angulation change to compensate for the lack of parallelism?
the vertical angulation can be increased by 5-15 degrees more than the beam alignment device indicates; however, image distortion will occur
What is a torus?
a bony growth seen in the oral cavity
What is the plural of the term torus?
tori
What is a maxillary torus?
a nodular mass of bone seen along the midline of the hard palate
What is a mandibular torus?
bony growths along the lingual aspect of the mandible
What is the palate?
the roof of the mouth
When using the paralleling technique, how should the image receptor be placed to compensate for maxillary torus?
the receptor must be placed on the far side of the torus; not on the torus
When using the paralleling technique, how should the image receptor be placed to compensate for mandibular torus?
the receptor must be placed between the tori and the tongue; not on the tori
If a patient cannot tolerate the placement of a periapical receptor when radiographing the mandibular premolars using the paralleling technique, how should the receptor placement be modified?
the receptor should be placed under the tongue to avoid impinging on muscle attachments and the lingual gingiva
What is the primary advantage of the paralleling technique?
to produce a radiographic image without dimensional distortion
What is the advantage of the accuracy when using the paralleling technique?
the image has dimensional accuracy and is highly representative of the actual tooth; there is maximum detail and definition
What is the bisecting technique?
an intraoral radiographic technique used to expose periapical receptors where the receptor is placed along the lingual surface of the tooth, the central ray is directed perpendicular to the imaginary bisector formed by the receptor and the long axis of the tooth, and the receptor holder or the patient’s finger is used to stabilize the receptor
What does the term angle mean?
a figure formed by two lines diverging from a common point
What does the term bisect mean?
to divide into two equal parts
What geometry principle is the bisecting technique based on?
the rule of isometry
What is the rule of isometry?
two triangles are equal id they have two equal angles and share a common side; this is what the bisecting technique is based on
How is the receptor placed when using the bisecting technique?
along the lingual surface of the tooth so that where the receptor touches the tooth, the plane of the receptor and the long axis of the tooth form an angle
What is the imaginary bisector?
an imaginary plane that divides in half the angle formed by the receptor and the long axis of the tooth in order to create two equal angles and provide a common side for the two imaginary equal triangles
How is the central ray directed when using the bisecting technique?
perpendicular to the imaginary bisector
What does the term angulation mean?
the alignment of the central ray beam in the horizontal and vertical planes
What is used to assist with proper angulation when exposing an intraoral radiograph?
beam alignment devices
What is horizontal angulation?
the positioning of the position indicating device and direction of the central ray beam in a horizontal or side-to-side plane
How is correct horizontal angulation achieved when exposing intraoral radiographs?
the central ray is directed perpendicular to the curvature of the arch and through the contact areas of the teeth
What occurs as a result of incorrect horizontal angulation in intraoral imaging?
incorrect horizontal angulation
What is vertical angulation?
positioning of the position indicating device in a vertical or up-and-down plane
What is the necessary vertical angulation when using the paralleling technique?
the vertical angulation of the central ray is directed perpendicular to the receptor and the long axis of the tooth
What is the necessary vertical angulation when using the bisecting technique?
the vertical angulation is determined by the perpendicular positioning of the central ray to the imaginary bisector
What results from correct vertical angulation in intraoral images?
the dental image is that of the same length as that of the tooth
What results from correct horizontal angulation in intraoral images?
the contact areas of the teeth appear opened and the result is diagnostic
What results from incorrect horizontal angulation in intraoral images?
the contact areas of the teeth appear overlapped and thus nondiagnostic
What results from incorrect vertical angulation in intraoral images?
the dental image is not the same length as that of the tooth and appears elongated or foreshortening and therefore nondiagnostic
What are forshortened images?
radiographic images that appear shortened
What is forshortening?
a term describing images of teeth that appear too short as a result of excessive vertical angulation
What are elongated images?
radiographic images that appear too long
What is elongation?
a term used to describe the images of teeth that appear longer than the actual teeth, as a result of insufficient vertical angulation
What are the recommended degrees of vertical angulation for maxillary canines when using the bisecting technique?
+45 to +55 degrees
What are the recommended degrees of vertical angulation for mandibular canines when using the bisecting technique?
-20 to -30 degrees
What are the recommended degrees of vertical angulation for maxillary incisors when using the bisecting technique?
+40 to +50 degrees
What are the recommended degrees of vertical angulation for mandibular incisors when using the bisecting technique?
-15 to -25 degrees
What are the recommended degrees of vertical angulation for maxillary premolars when using the bisecting technique?
+30 to +40 degrees
What are the recommended degrees of vertical angulation for mandibular premolars when using the bisecting technique?
-10 to -15 degrees
What are the recommended degrees of vertical angulation for maxillary molars when using the bisecting technique?
+20 to +30 degrees
What are the recommended degrees of vertical angulation for mandibular molars when using the bisecting technique?
-5 to 0 degrees
List some advantages of using the bisecting technique.
-can be used without a beam alignment device when a patient has anatomy that does not allow for placement (shallow palate, tori, etc)
-decreased exposure time when using a short 8-inch position indicating device
What is the primary disadvantage of using the bisecting technique?
dimensional distortion
What is the common term used for “caries?”
decay
List the anatomy included on a bite-wing radiograph.
-crowns of maxillary and mandibular teeth
-interproximal areas of teeth
-areas of crestal bone
What is the bite-wing technique?
a method used to examine the interproximal surfaces of teeth
What does the term interproximal mean?
between two adjacent areas
What is alveolar bone?
bone that supports and encases the roots of teeth
What is crestal bone/alveolar crest?
the coronal portion of alveolar bone found between teeth
What are contact areas of teeth?
-the area of a tooth that touches an adjacent tooth
-the area where adjacent tooth surfaces touch each other
How is a horizontal bite-wing receptor placed in the mouth?
the receptor is placed with the long portion of the receptor in a horizontal position
How is a vertical bite-wing receptor placed in the mouth?
the receptor is placed with the long portion of the receptor in a vertical position
How do opened contacts appear on a dental image?
thin radiolucent lines between adjacent tooth surfaces
What are overlapped contacts on a dental image?
the area where contact area od one tooth is superimposed over the contact area of an adjacent tooth