Quiz Questions - Theoretical Aspects of Intraoral Techniques

Which of the following about receptor placement is correct? 1. Anterior receptors are placed horizontally. 2. Anterior receptors are placed vertically. 3. Posterior receptors are placed horizontally. 4. Posterior receptors are placed vertically.

2. Anterior receptors are placed vertically. & 3. Posterior receptors are placed horizontally.

Match the definition to term: A. Dentulous B. Edentulous C. Periapical receptor D. Bite-wing receptor E. Occlusal receptor F. Intraoral receptor G. Extraoral receptor H. Maxilla I. Mandible J. Occlude K. Occlusion 1. A receptor placed inside the mouth. 2. The lower jaw. 3. Without teeth. 4. To close or bite. 5. A receptor used to examine a large area of the maxilla or mandible in one image. 6. A receptor used to examine the crowns of the maxillary and mandibular teeth on a single image. 7. A receptor placed outside the mouth. 8. With teeth. 9. The upper jaw. 10. A receptor used to examine the entire tooth and supporting bone.

1. A receptor placed inside the mouth. - Intraoral receptor 2. The lower jaw. - Mandible 3. Without teeth. - Edentulous 4. To close or bite. - Occlude 5. A receptor used to examine a large area of the maxilla or mandible in one image. - Occlusal receptor 6. A receptor used to examine the crowns of the maxillary and mandibular teeth on a single image. - Bite-wing receptor 7. A receptor placed outside the mouth. - Extraoral receptor 8. With teeth. - Dentulous 9. The upper jaw. - Maxilla 10. A receptor used to examine the entire tooth and supporting bone. - Periapical receptor

List the general diagnostic criteria for intraoral radiographs?

1. Dental images must display optimal density, contrast, definition, and detail. 2. Dental images must display the least amount of distortion possible; images must be of the same shape and size as the object being radiographed. 3. The complete mouth radiographic series (CMRS) must include images that show all tooth-bearing areas, including dentulous and edentulous regions. 4. Periapical images must show the entire crowns and roots of the teeth being examined, as well as 2 to 3 mm beyond the root apices. 5. Bite-wing images must show open contacts, or interproximal tooth surfaces that are not overlapped.

Identify the exposure technique error seen in each radiograph. 1. Figure 20-27 = 2. Figure 20-28 = 3. Figure 20-29 = 4. Figure 20-30 = 5. Figure 20-31 = 6. Figure 20-32 = 7. Figure 20-33 = 8. Figure 20-34 = 9. Figure 20-35 = 10. Figure 20-36 =

1. Figure 20-27 = 2. Figure 20-28 = 3. Figure 20-29 = 4. Figure 20-30 = 5. Figure 20-31 = 6. Figure 20-32 = 7. Figure 20-33 = 8. Figure 20-34 = 9. Figure 20-35 = 10. Figure 20-36 =

Match the letter of the item (pg 207, figure 18-26 to figure 18-28) with the definition. 1. In figure 18-26, identify the angle that is bisected correctly. = 2. In figure 18-27, identify the central ray that is correctly positioned perpendicular to the imaginary bisector. = 3. In figure 18-28, identify the PID that is aligned correctly. = 4. In figure 18-28, identify the vertical angulation the results in foreshortening. = 5. In figure 18-28, identify the vertical angulation that results in elongation. = 6. In figure 18-27, idenitfy the correct vertical angulation. =

1. In figure 18-26, identify the angle that is bisected correctly. = A 2. In figure 18-27, identify the central ray that is correctly positioned perpendicular to the imaginary bisector. = C 3. In figure 18-28, identify the PID that is aligned correctly.=A 4. In figure 18-28, identify the vertical angulation the results in foreshortening. = C 5. In figure 18-28, identify the vertical angulation that results in elongation. = B 6. In figure 18-27, idenitfy the correct vertical angulation. = A

Match the appropriate items (pg 178, figure 17-28) with the description. 1. No.1 size receptor = 2. No.2 size receptor = 3. XCP aiming ring, posterior = 4. XCP aiming ring, anterior = 5. XCP indicator arm, posterior = 6. XCP indicator arm, anterior = 7. XCP bite-block, posterior = 8. XCP bite-block, anterior =

1. No.1 size receptor = H 2. No.2 size receptor = G 3. XCP aiming ring, posterior = F 4. XCP aiming ring, anterior = E 5. XCP indicator arm, posterior = A 6. XCP indicator arm, anterior = B 7. XCP bite-block, posterior = C 8. XCP bite-block, anterior = D

Match the letter of the item (pg 207, figure 18-25) with the description. 1. Plane of the receptor = 2. Long axis of the tooth = 3. Imaginary bisector = 4. Central ray =

1. Plane of the receptor = D 2. Long axis of the tooth = B 3. Imaginary bisector = C 4. Central ray = A

State the five rules of the paralleling technique?

1. Receptor placement - the receptor must be positioned to cover the prescribed area of teeth to be examined. 2. Receptor position - The receptor must be positioned parallel to the long axis of the tooth. The receptor and the beam alignment device must be placed away from the teeth and toward the middle of the oral cavity. 3. Vertical angulation - the central ray of the x-ray beam must be directed perpendicular to the receptor and the long axis of the tooth. 4. Horizontal angulation - the central ray of the x-ray beam must be directed through the contact areas between the teeth. 5. Film receptor exposure - the x-ray beam must be centered on the receptor to ensure that all areas are exposed. Failure to center the x-ray beam results in a partial image on the receptor or a "cone-cut". Cone-cuts can be produced with either a round or rectangular PID.

Which of the following definitions is incorrect? A. Parallel: always separate by the same distance. B. Intersecting: to cut through. C. Right angle: formed by two parallel lines. D. Central ray: central portion of the x-ray beam.

C. Right angle: formed by two parallel lines.

Describe why a beam alignment device must be used in the paralleling technique?

A beam alignment device must be used to keep the receptor parallel with the long axis of the tooth. The patient cannot hold the receptor in this manner.

Which of the following describes the relationship between the receptor and the long axis of the tooth in the paralleling technique? A. The receptor and the tooth are parallel to each other. B. The receptor and the tooth are at right angles to each other. C. The receptor and the tooth are perpendicular to each other. D. The receptor and the tooth are intersecting each other.

A. The receptor and the tooth are parallel to each other.

Why is an increased target-receptor distance required in the paralleling technique? A. To avoid image magnification. B. To avoid distortion. C. To reduce scatter radiation. D. To improve receptor placement.

A. To avoid image magnification. Results in less image magnification and increase definition to compensate for image magnification from increased object-recpetor distance.

Which of the following are advantages of the paralleling technique? 1. Increased accuracy. 2. Simplicity of use. 3. Ease of duplication. 4. Ease of receptor placement. A. 1,2,3,&4 B 1,2,&3 C. 2,3,&4 D. 1,3,&4

B 1,2,&3 1. The paralleling technique produced an image that has dimensional accuracy; the image is highly representative of the actual tooth. 2. The paralleling technique is simple and easy to use and learn. The use of a beam alignment device eliminates the need to determine horizontal or vertical angulations and eliminates the chances of dimensional distortion. 3. The paralleling technique is easy to standardize and can be accurately duplicated, when serial radiographs are indicated.

Which of the following describes the relationship of the central ray to the receptor in the paralleling technique? A.20 degrees to the long axis of the tooth. B 90 degrees to the receptor and long axis of the tooth. C. 75 degrees to the long axis of the tooth. D. 15 degreed to the receptor and the long axis of the tooth.

B 90 degrees to the receptor and long axis of the tooth. The central ray is perpendicular to the tooth and the receptor.

Which of the following about the exposure sequence for periapical receptors is incorrect? A. Anterior receptors are always exposed before posterior receptors. B. Either anterior or posterior receptors may be exposed first. C. In posterior quadrants, the premolar receptor is always exposed before the molar receptor. D. When exposing anterior receptors, work from the patient's right to left in the maxillary arch and left to right in the mandibular arc.

B. Either anterior or posterior receptors may be exposed first.

Which of the following about the lack of parallelism between the receptor and the long axis of the tooth is correct? A. If the lack of parallelism is greater than 30 degrees, the image is generally acceptable. B. If the lack of parallelism is less than 20 degrees, the image is generally acceptable. C. If the lack of parallelism is less than 50 degrees, the image is generally acceptable. D. If the lack of parallelism is greater than 50 degrees, the image is generally acceptable.

B. If the lack of parallelism is less than 20 degrees, the image is generally acceptable.

Which of the following describes the distance between the receptor and the tooth in the paralleling technique? A. The receptor is placed as close as possible to the tooth. B. The receptor is placed away from the tooth and toward the middle of the oral cavity. C. Either A or B. D. None of the above.

B. The receptor is placed away from the tooth and toward the middle of the oral cavity. The object-receptor distance must be increased to keep receptor parallel with long axis of the tooth.

What piece of equipment is required to hold the receptor parallel to the long axis of the tooth in the paralleling technique?

Beam alignment device

What happens to the image when the object-receptor distance is increased?

Increased magnification

List examples of extraoral examinations?

Panoramic Lateral jaw Lateral cephalometric Posteroanterior Waters Submentovertex Reverse Towne Transcranial Tomographic projections

Discuss the patient and equipment preparations that must be completed before using the paralleling technique?

Patient: 1. Briefly explain the radiographic procedure to the patient. 2. Adjust chair so patient is positioned upright in chair and a comfortable working height. 3. Adjust headrest to support and position patient's head. Maxillary arch parallel to floor and midsagittal plane perpendicular to floor. 4. Place and secure lead apron with thyroid collar on the patient. 5. Remove all objects from patients mouth and remove eyeglasses. Equipent: 1. Set exposure factors on the x-ray unit according to the recommendations of the manufacture of the imaging receptors. 2. Open the sterilized package containing the beam alignment devices, and assemble it over a covered work area.

List the 3 types of intraoral radiographic examinations?

Periapical examination Interproximal examination Occlusal examination

How is the patient's head positioned before exposing receptors?

Positioned so that the maxillary arch is parallel to the floor and the midsagittal plane is perpendicular to the floor.

Describe the purpose, type of receptor, and technique used for occlusal examination?

Purpose: Examine large areas of the maxilla and mandible on one image. Type of Imaging Receptor: The occlusal receptor; the patient "occludes", or bites, on the entire receptor. Technique: The occlusal technique.

Describe the purpose, type of receptor, and technique used for interproximal examination?

Purpose: Examine the crowns of both maxillary and mandibular teeth on a single image. Is useful in examining adjacent tooth surfaces and crestal bone. Type of Imaging Receptor: The bite-wing receptor; has a "wing" or tab attached to it and the patient "bites" on the wing to stabilize the receptor. Technique: The bite-wing technique.

Describe the purpose, type of receptor, and technique used for periapical examination?

Purpose: Examine the entire tooth (crown & root) and supporting bone. Type of Imaging Receptor: The periapical receptor; periapical images show the terminal end of the tooth root and surrounding bone as well as the crown. Technique: (1) The paralleling technique (2) The bisecting technique

Which bean alignment devices are recommended for use with the paralleling technique to reduce radiation exposure of the patient?

Rinn XCP with snap-on ring collimators & Precision film holders. -These two beam alignment devices are recommended because their aiming rings aid in the alignment of the PID with the receptor to reduce the amount of patient exposure to radiation.

Explain the modifications in the paralleling technique that are used for shallow palate, bony growths, or a sensitive premolar region?

Shallow palate (low palatal vault): Tilting of the bite-block occurs, which results in a lack of parallelism between the receptor and the long axis of the tooth. If lack of parallelism exceeds 20 degrees... 1. Cotton role can be placed on the tooth not being radiographed. 2. Vertical angulation can be increased by 5-15 degrees more than the XCP instrument indicates, however image distortion occurs. Bony Growths (Torus/Tori): Maxillary torus (torus palatinus) and Mandibular tori (torus mandibularis) cause problems with the receptor placement. 1. For maxillary torus, the receptor must be placed on the far side of the torus and then exposed. 2. For mandibular tori, the receptor must be placed between the tori and the tongue

What size receptor is typically used with the anterior XCP instrument?

Size 1

What size is used with the posterior XCP instrument?

Size 2

What happens to the dental image when a short (8-inch) PID is used?

The image is magnified because it is not compensating for the object-film distance, whereas the 16-inch would.

Discuss prescription of dental radiographs?

The prescription of dental radiographs is based on the individual needs of the patient; every patients dental condition is different. New patient Signs of disease History of extensive dental treatments

State the basic principle of the paralleling technique?

The technique is based on the concept of parallelism. -The receptor is placed in the mouth parallel to the long axis of the tooth. -The central ray of the x-ray beam is directed perpendicular to the receptor of the long axis of the tooth. - A beam alignment device must be used to keep the receptor parallel with the long axis of the tooth.

T/F: The advantages of paralleling technique outweigh the disadvantages.

True

What do the letters X, C, and P stand for?

X = extension C = cone P = paralleling

Summarize the guidelines for periapical receptor positioning with the paralleling technique?

pg 164 box 17-3