Exam 2 (Chs. 5, 6 & 12, 13, 15) Flashcards

Question

Which of the following is the correct seating position for the patient during radiographic examinations when an image receptor without an external aiming device is used? a. Occlusal plane-parallel and midsaggital plane perpendicular to the floor b. Occlusal plane perpendicular and midsaggital plane-parallel to the floor c. Occlusal and midsaggital planes parallel to the floor d. Occlusal and midsaggital planes perpendicular to the floor

Answer 1

a.Occlusal plane-**parallel** and midsaggital plane **perpendicular** to the floor

Answer 2

d.all of the above technique

Answer 3

b.Maxillary **anteriors**, mandibular **anteriors**, maxillary **posteriors**, mandibular **posteriors**

Answer 4

d.Object (tooth) and image receptor should be as **close as possible** to each other

Answer 5

a.increased.

Answer 6

d.Easy technique for child

Answer 7

c.parallel to the teeth.

Answer 8

b.long biteblock and L-shaped backing.

Answer 9

d.105-degree angled backing

Answer 10

c.Premolar

Answer 11

a.first and second molars.

Answer 12

c.first and second premolars.

Answer 13

b.Vertical angulation

Answer 14

d.inadequate vertical angulation

Answer 15

b.The first statement is false. The second statement is true.

Answer 16

b. first & second premolars

Answer 17

d. inadequate vertical angulation

Answer 18

d. Irradiated cells cannot be repaired.

Answer 19

b. Ions have a strong tendency to seek out new combinations.

Answer 20

c. White blood cells ## Footnote *According to the Law of Bergonié and Tribondeau, actively dividing cells such as white blood cells are more sensitive to radiation than are slowly dividing cells*

Answer 21

a. Somatic cells cannot repair radiation damage. * Relatively minor radiation damage can be repaired in healthy individuals at the rate of 75 percent within 24 hours in somatic cells, whereas radiation damage to reproductive cells cannot be repaired*.

Answer 22

a. There is a dose below which no biological response would be expected. * A threshold dose-response curve indicates that there is a “threshold” amount of radiation below which no biological response would be expected.*

Answer 23

d. Cell becomes radioactive. ## Footnote *Several responses are possible, but the cell does not become radioactive.*

Answer 24

a. The smaller the area of tissue exposure, the greater damage to the individual. ## Footnote *The smaller the area exposed, the less likely there will be radiation-induced damage.*

Answer 25

b. The lethal dose (LD 50/30) for humans is 1.5 grays. ## Footnote *The LD 50/30 for humans is **4.5 grays***

Answer 26

d. **4.5 grays.** ## Footnote *The LD 50/30 for humans is 4.5 grays.*

Answer 27

a. Constipation ## Footnote *Diarrhea, and not constipation, is a symptom of acute radiation syndrome.*

Answer 28

a. Actively dividing cells are less sensitive. ## Footnote *Cells with a potential for rapid division are more sensitive to radiation than those that do not divide.*

Answer 29

b. Reproductive, bone, nerve, muscle ## Footnote *The more specialized a cell is, the more radioresistant it is. The exceptions to this law are white blood cells (lymphocytes) and reproductive cells (oocytes), which do not divide and are very specialized, and yet are radiosensitive.*

Answer 30

c. It may produce offspring with increased resistance to radiation exposure. ## Footnote *The experts do not fully understand all the effects of radiation exposure or their future consequences, but there is no evidence that radiation exposure produces an immunity to radiation effects in future generations.*

Answer 31

a. 30 mSv ## Footnote *A full mouth series of 18 F-speed films, exposed at 90 kVp with a 16-inch [41-cm]-length PID is approximately 30 mSv skin exposure.*

Answer 32

b. The latent period ## Footnote *Following the initial radiation exposure, and before the first detectable effect occurs, a time lag called the “latent period” occurs.*

Answer 33

b. deterministic effect. ## Footnote *When the severity of the change is dependent on the dose, the effect is called a “deterministic effect.”*

Answer 34

d. **1.0 Gy** ## Footnote *If the dose of radiation is large enough (generally over 1.0 Gy or 100 rads, whole body), the resultant signs and symptoms that comprise these short-term effects are collectively known as acute radiation syndrome (ARS).*

Answer 35

c. a **cumulative** effect. ## Footnote *A cumulative effect refers to the theory that radiation-exposed tissues accrue damage and may function at a diminished capacity with each repeated exposure.*

Answer 36

c. Indirect ## Footnote *Indirect theory is based on the assumption that radiation can cause chemical damage to the cell by ionizing the water within it. Ionization dissociates water into hydrogen and hydroxyl radicals that can form new chemicals such as hydrogen peroxide that act as toxins (poisons) to the body, causing cellular dysfunction.*

Answer 37

b. The first statement is false. The second statement is true. ## Footnote *A **nonthreshold dose-response** relationship indicates that **any dose**, regardless of amount, can be expected to produce a biologic response. A linear dose-response relationship indicates that the biologic response is directly proportional to the dose.*

Answer 38

True ## Footnote *Much of our knowledge base regarding the negative effects of exposure to radiation comes from extrapolated data using high doses and dose rates. Scientists do not know whether a threshold level exists, below which radiation would be safe. To err on the side of caution, the radiation protection community assumes that any dose of radiation may pose a risk.*

Answer 39

False ## Footnote *According to the Law of Bergonié and Tribondeau, the **more specialized** a cell is, the more **radioresistant** the cell.*

Answer 40

False ## Footnote *A threshold dose-response curve indicates that there is a _threshold amount_ of radiation below which no biological effects would be expected.*

Answer 41

True ## Footnote *Radiation biologists are not certain whether a threshold radiation dose exists. Therefore, radiation protection guidelines assume that every dose of radiation produces damage and should be kept to the minimum necessary to meet diagnostic requirements.*

Answer 42

True ## Footnote *Both of these will affect the potential of a biological effect.*

Answer 43

False ## Footnote *Individuals vary in sensitivity within the same species. Some individual’s **genetic makeup predisposes them to be more sensitive to genetic damage** from radiation than other individuals.*

Answer 44

False ## Footnote *There is a wide variation in sensitivity to radiation among different types of cells and tissues. Cells that rapidly divide are much more sensitive to radiation than specialized cells, which rarely, if ever, divide.*

Answer 45

True ## Footnote *Anything capable of **causing cancer is called a “carcinogen.**” X-rays can cause cancer by a variety of mechanisms.*

Answer 46

True ## Footnote *The maxillofacial structures, composed largely of specialized tissues such as bone, nerve, and muscle, are relatively radioresistant.*

Answer 47

True ## Footnote *The first half of the Law of Bergonié and Tribondeau states that actively dividing cells, such as red blood cells, are more sensitive than slowly dividing cells.*

Answer 48

True ## Footnote *Radiobiologists have been unable to determine what, if any, effects result from exposure to very low levels of radiation.*

Answer 49

False ## Footnote ***Radioresistant** refers to a substance or tissue that is **not easily injured** by ionizing radiation.*

Answer 50

False ## Footnote ***The latent period refers to the time between exposure to radiation and the first clinically observable symptoms.***

Answer 51

False ## Footnote *When radiation affects all body cells **except the reproductive cells**, it is called a “**somatic effect.”***

Answer 52

True *When a biological response is based on the probability of occurrence rather than the severity of the change, it is called a “**stochastic effect**.”*

Answer 53

True ## Footnote *The occurrence of cancer is a stochastic effect of radiation exposure; it is an “all-or-nothing” occurrence.*

Answer 54

False *Erythema, or reddening of the skin, is expected to be more or less severe with an increase or decrease in radiation dose, respectively. When the severity of the change is dependent on the dose, the effect is called a “**deterministic effect.”*

Answer 55

False ## Footnote *Reproductive cells (oocytes) are very radiosensitive even though they do not divide and are very specialized. They are one of the exceptions to the Law of Bergonié and Tribondeau.*

Answer 56

True *The Law of Bergonié and Tribondeau states that actively dividing, specialized cells are usually radioresistant. The exceptions to this law are white blood cells (lymphocytes) and reproductive cells (oocytes), which do not divide, are very specialized and yet are radiosensitive.*

Answer 57

True ## Footnote *Background radiation, defined as ionizing radiation that is always present in our environment, exposes the population of the United States to approximately 8 µSv (microsieverts) per day.*

Answer 58

b. Radiographs must be taken on all new patients. ## Footnote *In maintaining ALARA, copies of radiographs, if available, taken at another practice should be requested to avoid unnecessary additional radiation exposure to the patient.*

Answer 59

c. They understand how to perform dental x-ray machine inspections ## Footnote *While the dental assistant and dental hygienist may perform quality control tests periodically on dental x-ray machines, inspections, especially when required by law, are to be performed by a qualified radiological technician.*

Answer 60

d. A pointed, closed-end PID is acceptable. ## Footnote *Only round or rectangular **open-ended** PIDs are currently acceptable.*

Answer 61

a. A short (8 in/20.5 cm) PID delivers less radiation to the patient. ## Footnote *A long (12 or 16 in/30 or 41 cm) PID produces a less divergent x-ray beam, resulting in an exit beam diameter that exposes the patient less than a short (8 in/20.5 cm) PID.*

Answer 62

c. Pointed, closed-end plastic cone PIDs should no longer be used. ## Footnote *The tip of the pointed cone was supposed to indicate the central ray and aid in positioning. However, x-rays are deflected through contact with the material of the pointed cone, producing scatter radiation, so their use should be discontinued*

Answer 63

b. They should be folded and stored when not in use. ## Footnote *Lead aprons should be stored flat or hung unbent. Folding the lead apron may cause the material to crack, rendering the apron defective.*

Answer 64

c. F ## Footnote *E-speed film provides a 50 percent reduction in radiation exposure over D-speed. F-speed film provides a 20 percent reduction in radiation exposure over E-speed.*

Answer 65

d. It is acceptable to increase the dose while underdeveloping the film if time is short. ## Footnote *While increasing the dose and underdeveloping the film may produce an acceptable image and save time, it is unethical to unnecessarily increase radiation dose to a patient.*

Answer 66

a. The ideal angle to stand from the path of the exiting x-ray beam is 180 degrees. * The ideal angle to stand from the path of the exiting x-ray beam is 45 degrees.*

Answer 67

c. Personnel monitoring devices protect the wearers from scatter radiation. ## Footnote *The radiation monitoring device cannot protect the wearer from radiation. The device indicates that an exposure has occurred.*

Answer 68

c. Holding the image receptor in the patient’s mouth ## Footnote *The radiographer must never hold the image receptor in the patient’s mouth. A guardian or caregiver may assist if necessary but must be protected with lead/lead-equivalent barriers. Using an assistant will have no effect on reducing the radiation dose to the patient.*

Answer 69

a. any radiation dose that can be reduced without major difficulty, great expense, or inconvenience, should be reduced or eliminated. ## Footnote *The ALARA concept implies that any radiation dose that can be reduced without major difficulty, great expense, or inconvenience should be reduced or eliminated.*

Answer 70

d. use evidence-based selection criteria for prescribing radiographs. * The most important way to ensure that the patient receives a reasonably low dose of radiation is to use evidence-based* *selection criteria* *when determining which patients need radiographs.*

Answer 71

d. All of the above. ## Footnote *Evidence-based selection criteria guidelines are applied only after reviewing the patient’s health history and completing a clinical examination.*

Answer 72

b. reduce the size of the x-ray beam. * The collimator constricts the diameter of the x-ray beam to reduce the radiation dose to the patient by reducing the volume of tissue exposed.*

Answer 73

d. absorb the less penetrating **long wavelengths** to reduce radiation exposure. * A filter is an absorbing material (usually aluminum) placed in the path of the x-ray beam to remove a high percentage of the soft x-rays (the longer wavelengths) and reduce patient radiation dose.*

Answer 74

c. create a smaller diameter of exposure. ## Footnote *The less divergent x-ray beam creates a smaller diameter of exposure.*

Answer 75

d. Rectangular PIDs. ## Footnote *Rectangular PIDs reduce patient radiation dose by 70 percent.*

Answer 76

a. Wearing a personnel-monitoring device ## Footnote *Personnel-monitoring devices play a valuable role in recording radiation exposures, but they do not stop radiation from exposing the wearer.*

Answer 77

c. protect the operator from receiving radiation. ## Footnote *Personnel-monitoring devices play a valuable role in recording the amount and type of radiation received, but they do not stop radiation from exposing the wearer.*

Answer 78

True ## Footnote *While gaining diagnostic benefits from dental radiographs with zero exposure would be ideal, that is not possible. However, the oral health care team should strive for low-dose, high-yield radiography by obtaining the maximum information with the lowest possible dose.*

Answer 79

True ## Footnote *Expert-recommended evidence-based guidelines are available for the dentist to consult.*

Answer 80

False ## Footnote *Round collimators must restrict the x-ray beam to 2.75 inches (7 cm) at the patient end of the PID, while rectangular collimators expose an area slightly greater than a size #2 film. Considerable excess radiation that contributes nothing to the image occurs with round collimation.*

Answer 81

True ## Footnote *Use of aluminum filters removes from the beam a high percentage of low-energy x-rays that increase radiation exposure but do not contribute useful information to the image.*

Answer 82

True ## Footnote *There are currently three commercially available dental x-ray film speeds: D, E, and F. Compared to D-speed film, E-speed film is twice as fast and requires only half the exposure. F-speed film further reduces radiation exposure by 20 percent compared to E-speed film.*

Answer 83

False ## Footnote *In the past, unethical practitioners might not replenish or change processing chemical solutions according to schedule in order to save time and money. To compensate for the weakening solutions, an increase in radiation dose would be used. It is unethical practice to knowingly use a higher dose of radiation than necessary to achieve a diagnostic image.*

Answer 84

True ## Footnote *TLDs contain lithium fluoride crystals which, when heated after exposure to radiation, give off energy in the form of visible light. The amount of light emitted is proportional to the amount of radiation absorbed by the crystals, making TLDs very accurate radiation monitoring devices.*

Answer 85

True ## Footnote *The MPD for the general public is 5 mSv/year. The dose is higher for radiation workers but is still far below a level capable of causing detectable damage.*

Answer 86

False ## Footnote *Necessary medical or dental diagnostic or therapeutic radiation is not counted in the MPD. If a patient needs radiographic services, then that patient needs radiographic services.*

Answer 87

True ## Footnote *There are regulations promulgated by federal and state, and in some cases, county and city, governments which all need to be followed. The oral health care practice needs to be aware of and comply with all regulations that govern the use of ionizing radiation.*

Answer 88

True *The United States Nuclear Regulatory Commission has developed radiation protection guidelines referred to as the* *maximum permissible dose (MPD)* *for the protection of radiation workers and the general public.*

Answer 89

True ## Footnote *The ALARA concept implies that any radiation dose that can be reduced without major difficulty, great expense, or inconvenience should be reduced or eliminated.*

Answer 90

False ## Footnote *Federal regulations require that the intraoral x-ray beam be collimated to a diameter of **2.75** inches at the patient’s skin.*

Answer 91

False *A drifting tube head should never be held during the exposure either by the radiographer or the patient.* *Radiation leakage* *from the tube head can be significant. If the tube head drifts, it should be serviced to stabilize it.*

Answer 92

* True* * Not every undiagnostic radiograph must be retaken. If multiple radiographs are taken at the same time, the radiographer should check to see if the area of interest is imaged on an adjacent radiograph. Sometimes a retake radiograph may be avoided if the area of interest is imaged diagnostically on an adjacent radiograph.*

Answer 93

False ## Footnote *Based on evidence-based selection criteria, an adult recall patient with no risk factors for caries would most likely be assessed for bitewing radiographs every 24 to 36 months.*

Answer 94

True ## Footnote *Based on evidence-based selection criteria, a child recall patient with several risk factors for caries would most likely be assessed for bitewing radiographs every 6 to 12 months.*

Answer 95

True ## Footnote *A high level of caries experience or demineralization is one of the factors increasing risk for caries listed by the evidence-based selection criteria.*

Answer 96

False ## Footnote ***Low-energy** x-rays are harmful to the patient because they are absorbed by the skin, increasing the patient’s dose.*

Answer 97

b. Anxiety ## Footnote *Appearance, attitude, interpersonal skills, and communication are needed to gain patient trust and confidence. A confident radiographer will foster confidence in the patient, who, in turn, will be better able and willing to follow directions during the procedure.*

Answer 98

c. If a patient has concerns regarding x-ray exposure, the radiographer should tell the patient not to worry, everything will be okay. ## Footnote *Statements such as “Don’t worry” and “Everything will be okay” convey an attitude of apathy or imply that the patient’s feelings do not matter.*

Answer 99

a. The radiographer should praise the patient for their assistance with the procedure. ## Footnote *Positive reinforcement and feedback that the procedure is going well will help foster more cooperation.*

Answer 100

d. In an uncomfortable discussion, avoid eye contact with the patient. ## Footnote *Effective use of words in verbal communication begins with facing the patient directly and maintaining eye contact.*

Answer 101

a. Nonverbal communication is not very believable. ## Footnote *We usually use a combination of verbal and nonverbal communication. Nonverbal communication is very believable and often conveys the strongest message.*

Answer 102

b. Adults generally need x-rays more often than children. ## Footnote *Children generally need dental x-rays more often than adults because they are still developing and the teeth are more likely to be affected by decay than those of adults.*

Answer 103

c. The amount of radiation absorbed by the tissue is referred to as the dose. ## Footnote *When human tissue is exposed to radiation, some of the energy is absorbed and some passes through without effect. The amount of energy absorbed by the tissue is the dose.*

Answer 104

a. The radiographer must remain in the room during the exposure to be sure the patient does not move. ## Footnote *If the radiographer did not leave the room or stand behind a barrier, he/she would be exposed to needless radiation many times a day. Even though the amount of exposure each time is small, the cumulative dose over time is not necessary.*

Answer 105

c. It has been linked to full-term, low birth-weight infants. ## Footnote *Dental radiography during pregnancy is associated with low birth weight, especially in full-term pregnancies. Whether dental radiation affects the reproductive organs directly or whether exposure of the thyroid gland affects pregnancy outcomes indirectly is not yet known.*

Answer 106

b. Use the slowest film speed currently available. ## Footnote *The fastest type of x-ray film currently available should be used to minimize exposure.*

Answer 107

d. “Your radiographs are too dark but we corrected the problem. Let’s take them again.” ## Footnote *Being honest about problems gains patient’s confidence. However, care must be taken to not imply that defective equipment has been used on the patient.*

Answer 108

a. ask the patient to pronounce his or her name for you. ## Footnote *Always greet the patient by name. Address the patient using their proper title (Miss, Mrs., Ms., Mr., Dr., etc.) and last name. If you are uncertain of the correct pronunciation of the patient’s name, ask the patient to pronounce it for you.*

Answer 109

b. “This is an easy procedure, but I need you to help by slowly closing.” ## Footnote *If the radiographer feels that the procedure is uncomfortable or unnecessary, these feelings will be conveyed to the patient. The radiographer should not impose his or her own feelings onto the patient.*

Answer 110

c. "This won't hurt a bit." ## Footnote *Telling the apprehensive patient, “This won’t hurt a bit” may convey an attitude of apathy, or imply that the patient’s apprehensions do not matter.*

Answer 111

a. facing the patient directly, maintaining eye contact, and giving specific directions. * Effective use of words in* *verbal communication begins with facing the patient directly and maintaining eye contact.*

Answer 112

d. Periapical ## Footnote *The radiographer’s choice of words and sentence structure are important. Words used should be at a level the patient can understand. Too many highly technical words may confuse the patient and result in misunderstandings.*

Answer 113

d. All of the above * Nonverbal communication includes gestures, facial expressions, body movement, and listening.*

Answer 114

c. Whenever the child needs them ## Footnote *How often radiographs (dental x-rays) should be taken depends on the patient’s individual health needs. It is important to recognize that just as each patient is different from the next, so should the scheduling of x-ray exams be individualized for each patient.*

Answer 115

b. “To protect you from possible scatter radiation.” * Lead and other materials that simulate lead used in protective aprons and thyroid collars absorb potential scatter radiation and protect other parts of the body from unnecessary radiation.*

Answer 116

a. attitude. ## Footnote *Attitude is defined as the position assumed by the body in connection with a feeling or mood.*

Answer 117

True ## Footnote *Attitude plays a significant role in gaining the patient’s trust in the radiographer’s ability. A fresh, positive attitude with each new patient will most likely encourage a cooperative patient.*

Answer 118

True ## Footnote *Patients can sense the health care professional’s attitude, by the way he/she walks, talks, and behaves. Patients will easily sense disgruntled members of the oral health care team. Maintaining a pleasant, positive attitude will help generate the same from patients.*

Answer 119

False ## Footnote *Empathy is the ability to share another’s emotions or feelings. Apathy implies that a patient’s emotions and apprehensions do not matter.*

Answer 120

False ## Footnote *If placement of the image receptor during the radiographic procedure is uncomfortable, show empathy. Empathy is the ability to share in another’s feelings. If discomfort must be tolerated to produce the necessary radiographs, empathetic, yet direct and tactful communication can bring the desired result.*

Answer 121

False ## Footnote *The patient will assume that discomfort means incorrect placement and will feel obligated to tell the radiographer of any and all feelings associated with placements.*

Answer 122

False ## Footnote *This query will likely cause the patient to move to answer the radiographer, defeating the purpose of the request. The command, “Hold still, please” is less likely to prompt the patient to move.*

Answer 123

True. ## Footnote *The radiographer may want the patient to close slowly, but by saying, “Close slowly, please” the patient may be closed before the radiographer says the word “slowly.” Rearranging the words to, “Slowly close, please” is more likely to produce the desired results.*

Answer 124

True ## Footnote *We usually use a combination of verbal and nonverbal communication.*

Answer 125

True *The ability to communicate is based on the radiographer’s knowledge, education, and training in the area of dental radiology. Many patients do not comprehend the enormous value of a radiographic exam of their teeth and supporting structures.*

Answer 126

False *Treatment without necessary radiographs is considered negligent care. A patient cannot sign a paper refusing radiographs releasing the dentist from liability. This would be consenting to negligent care, which is illegal.*

Answer 127

True ## Footnote *It is surprising how many patients do not comprehend the enormous value of a radiographic examination of their teeth and the supporting oral structures. An educated patient is more inclined to understand and accept dental treatment plans and embrace suggestions for oral health promotion and disease prevention.*

Answer 128

False ## Footnote *The dose of radiation required for dental x-rays is extremely small compared to that used for radiation therapy. The effects of very high doses involved in therapeutic radiation may increase susceptibility to diseases, such as tooth decay. This can occur as a result of a decrease in secretions of the salivary glands. It is especially important that patients who have had radiation therapy for cancer of tissues in the head or neck regions have dental x-ray exams as needed, to detect problems at an early stage.*

Answer 129

False ## Footnote *When the two methods are not in synch, the nonverbal communication usually conveys the strongest message. Patients feel that **actions speak louder than words.***

Answer 130

False *The use of* *show-tell-do as a method of combined verbal and nonverbal communication is useful in dental radiography for all patients, especially when barriers to communication exist such as in the case of a language or cultural difference, a sensory impairment, a cognitive impairment, and for children.*

Answer 131

False ## Footnote *A better answer to the patient question, “Why do I need x-rays?” is because many diseases cannot be detected by clinical exam alone.*

Answer 132

True ## Footnote *Interpersonal skills are used to communicate with others successfully. Respectfulness; courtesy; empathy; and patient, honest, and tactful communication are examples of interpersonal skills.*

Answer 133

True ## Footnote *Attitude will play a significant role in gaining the patient’s trust in the radiographer’s ability. The attitude of the radiographer toward the procedure will be conveyed to the patient. If the radiographer feels that the procedure is uncomfortable or unnecessary, these feelings will be conveyed to the patient. The radiographer should not impose his or her own feelings onto the patient.*

Answer 134

False ## Footnote ***Dismissing the patient’s fears may convey an attitude of apathy,** or imply that the patient’s apprehensions do not matter. If placement of an intraoral imaging receptor during the radiographic procedure is uncomfortable, show empathy.*

Answer 135

True *Because a demonstration of technical skill will build patient confidence, the radiographer should feel that his or her training and education provided adequate preparation for this role. Having confidence in oneself fosters confidence in others.*

Answer 136

False ## Footnote *The radiographer can verbally agree with the patient that excess radiation exposure is a concern and that the practice has adopted a strict radiation safety program*

Answer 137

c. Panoramic ## Footnote *Intraoral radiography consists of methods of exposing an image receptor placed inside the oral cavity. Bitewing, periapical, and occlusal examinations all involve the exposure of image receptors placed in the mouth, while the panoramic examination uses a receptor placed outside the mouth.*

Answer 138

a. Use the largest possible source of radiation (focal spot). ## Footnote *The smallest focal spot of radiation should be selected.*

Answer 139

c. The patient’s finger can be used to hold a large image receptor in position in the oral cavity. ## Footnote *An image receptor holder with an external aiming device will assist the radiographer with directing the x-ray beam at the correct angle. Using the patient’s finger to hold the image receptor in place during exposure is not acceptable.*

Answer 140

a. Four incisor periapical radiograph ## Footnote *Only one maxillary and one mandibular image receptor placed in the incisor areas would be required.*

Answer 141

a. A minimum of 10 periapical radiographs is required for a full mouth survey on an adult patient. ## Footnote *The number and size of image receptors used for a full mouth series of bitewing and periapical radiographs varies among oral health care practices. A minimum of 4 bitewing and 14 periapical radiographs*

Answer 142

b. The identification dot should be positioned toward the apices of the teeth when placing periapical radiographs. ## Footnote *The identification dot is used to differentiate the right from the left side of the patient. However, it has the potential to obscure information imaged on the film and therefore should be positioned away from the area of interest.*

Answer 143

a. Incorrect vertical angulation results in overlapped contact points. * Incorrect horizontal angulation results in overlapped contact points.*

Answer 144

b. Accurate vertical angulation is more important to the paralleling than the bisecting technique. ## Footnote *Although the vertical angulation settings vary between these two techniques, both the paralleling and the bisecting techniques require correct vertical angulation to produce diagnostic-quality radiographs.*

Answer 145

c. The open end of the PID should be placed two inches from the patient’s skin. ## Footnote *The open end of the PID should be placed as close to the patient’s skin as possible, without touching, to avoid an underexposed radiograph. As the beam of radiation spreads out, less radiation is available to strike the film and produce a diagnostic-quality radiograph.*

Answer 146

b. Vertical angulation is accomplished by directing the central ray parallel to the image receptor. ## Footnote *Vertical angulation is accomplished by directing the central ray **perpendicular** to the image receptor in the paralleling technique and perpendicular to the imaginary bisector when using the bisecting technique.*

Answer 147

d. When the open end of the PID is tilted toward the floor, the vertical angle is positive. ## Footnote *Vertical angulation is described in degrees, with the vertical angulation of the tube head and PID beginning at zero, where they are parallel to the floor. The vertical angulations, scaled in 5 or 10 degrees, are inscribed on the sides of the yoke, where the tube head is connected. When pointing down toward the floor, the vertical angulation is called “positive,” and when pointing up toward the ceiling, the vertical angulation is called “negative.”*

Answer 148

a. Bitewing radiographs record the apices of teeth and surrounding bone. ## Footnote *The fundamental purpose of the bitewing exam is to show the coronal portions of the teeth and alveolar crests of a segment of both the mandible and maxilla on one film. The periapical radiograph is designed to image the apices of teeth and surrounding bone.*

Answer 149

b. The paralleling technique arose through application of the rule of isometry. ## Footnote *The concept of the bisecting technique (also called “bisecting-angle” or “short-cone technique”) originated through application of a geometric principle known as the rule of isometry.*

Answer 150

d. All of the above. * The* *paralleling technique is* *also called “right-angle,” “extension-cone,” or “long-cone” technique.*

Answer 151

d. Teeth should be as close as possible to the radiation source. ## Footnote *The object (tooth) should be as far as practical from the target (source of radiation).*

Answer 152

a. parallel to the floor. ## Footnote *The vertical angulation of the tube head and the PID begins at zero. In the zero position, the PID is parallel to the plane of the floor.*

Answer 153

b. Cleft palate * Conditions prompting the exposure of a periapical radiograph include apical pathology (abscesses), fractures, large carious lesions, extensive periodontal involvement, examination of developmental anomalies such as missing teeth and abnormal eruption patterns, and any unexplained pain or bleeding. Occlusal radiographs would be a better choice for imaging a large area such as a cleft palate.*

Answer 154

d. 3 ## Footnote *A size #3 image receptor with dimensions of 1 1/16 inches by 2 1/8 inches is used for horizontal bitewing radiographs.*

Answer 155

c. 14 ## Footnote *The number and size of image receptors used for a full mouth series of bitewing and periapical radiographs varies among oral health care practices. A minimum of 4 bitewing and 14 periapical radiographs*

Answer 156

d. distinguish between the patient's right and left sides. * The* *identification dot, embossed into the film by the manufacturer, will be used during interpretation of the radiograph to distinguish between the patient’s right and left sides.*

Answer 157

True ## Footnote *X-rays producing an image on an image receptor is similar to light casting a shadow of an object. When a hand is placed between a light bulb and a countertop, a shadow of the hand appears on the countertop. In the same way, x-rays cast a shadow of the teeth on the image receptor.*

Answer 158

True ## Footnote *The open end of the PID should be placed as close to the patient’s skin as possible without touching. Failure to bring the end of the PID in close to the patient will result in an underexposed radiograph because as the beam of radiation spreads out, less radiation is available to strike the image receptor and produce a diagnostic-quality image.*

Answer 159

False ## Footnote *All deviations in which the PID is tilted toward the floor are called “positive angulations.”*

Answer 160

False ## Footnote *The purpose of the periapical examination is to view the entire tooth and surrounding bone.*

Answer 161

True ## Footnote *This name is given to the periapical radiograph because it images the entire tooth from the crown to the root end and the surrounding bone.*

Answer 162

False ## Footnote *Periapical radiographs are used to examine a single tooth or condition but more than one tooth will be imaged on a single radiograph.*

Answer 163

True ## Footnote *An image receptor holder with an external aiming device will assist the radiographer with directing the x-ray beam at correct angles.*

Answer 164

True ## Footnote *When using a size #2 image receptor in the anterior region, there is a tendency to bend film or phosphor plate corners to make it fit more comfortably. A solid-state digital sensor may impinge on sensitive tissues. Bending the image receptor distorts the image or damages the receptor. A smaller image receptor is often the better alternative.*

Answer 165

False ## Footnote *Periapical image receptors for exposure of posterior areas are placed with the long dimension horizontally. This is known as horizontal placement.*

Answer 166

True ## Footnote *Image receptors placed in the anterior regions should be oriented with the longer dimension vertical. This is known as vertical placement.*

Answer 167

False ## Footnote *The identification dot may obscure information in that portion of the image and should be positioned away from the area of interest. In the case of periapical radiographs, the identification dot should be positioned toward the incisal/occlusal edges, where it is least likely to interfere with diagnostic information.*

Answer 168

False ## Footnote *Placing the dot in the slot for periapical projections positions the identification dot **toward the occlusal or incisal edges, away from the apices of teeth.***

Answer 169

True ## Footnote *Incorrect horizontal angulation produces overlapped contact points. Incorrect vertical angulation using the paralleling technique results in cutting off a portion of the area of interest from the radiograph. Incorrect vertical angulation using the bisecting technique results in elongation or foreshortening of the image.*

Answer 170

False *The **bitewing** examination is sometimes referred to as an* ***interproximal radiograph.***

Answer 171

True. *The technique used to image* *bitewing radiographs is unique to the bitewing exam.*

Answer 172

False *The technique used to image* *bitewing radiographs* *is unique to the bitewing exam. However, because of the almost parallel relationship of the image receptor to the teeth, the bitewing technique could be considered a modification of the paralleling technique used for exposing periapical radiographs.*

Answer 173

True ## Footnote *Neither the paralleling nor the bisecting technique completely meets all five requirements for accurate shadow casting in all regions of the oral cavity on all patient types.*

Answer 174

False ## Footnote *The **size #4 film or phosphor plate is used exclusively for occlusal radiographs** of adult patients, and the **size #3 film** or phosphor plate is used exclusively for **horizontal bitewing radiographs** of adult patients.*

Answer 175

True *The bitewing survey may consist of two to eight radiographs. A complete set of seven or eight* *vertical bitewing radiographs may be exposed for the examination of a periodontally involved patient. This vertical bitewing set will include both posterior and anterior radiographs. When the patient does not require anterior bitewings, two or four posterior bitewing radiographs positioned either vertically or horizontally are usually taken.*

Answer 176

d. Bite blocks with an L-shaped back plate should be used with the bisecting technique. ## Footnote *Bite blocks with a 105-degree back plate should be used with the bisecting technique. The parallelling technique requires a bite block with an L-shaped (90˚) back plate.*

Answer 177

c. The patient’s eyeglasses may be left in place to protect the eyes. ## Footnote *The radiographer should ask the patient to remove the eyeglasses. If the metal or thick plastic frame of the eyeglasses lies in the path of the beam of radiation, they will be imaged onto the radiograph.*

Answer 178

a. Increasing the vertical angulation ## Footnote *Elongation results from inadequate vertical angulation.*

Answer 179

b. Decreasing the vertical angulation ## Footnote *Foreshortening results from excessive vertical angulation.*

Answer 180

c. Directing the central ray perpendicular to the plane of the image receptor ## Footnote *Overlapping error results when the central rays of the x-ray beam are directed obliquely toward the image receptor in the horizontal plane.*

Answer 181

a. -10 degrees ## Footnote *To obtain a radiograph with an accurate representation of the mandibular premolar, the central ray of the x-ray beam should be directed toward the imaginary bisector between the long axis of the canine and the plane of the image receptor in the vertical dimension at -10 degrees.*

Answer 182

True ## Footnote *When the palatal vault is high, the angulation can be decreased no more than 15 degrees because of the more vertical position of the image receptor. When the vault is low, the vertical angulation can be increased up to 15 degrees.*

Answer 183

True ## Footnote *The steps for determining correct horizontal angulation are the same for both the bisecting and paralleling techniques.*

Answer 184

False ## Footnote *The patient must be seated correctly with the midsaggital plane perpendicular to the floor and the occlusal plane parallel to the floor to use predetermined anatomical landmarks through which to direct the central ray of the x-ray beam.*

Exam 2 (Chs. 5, 6 & 12, 13, 15) Flashcards

Ch 5 added Ch 6 added Ch 12 added Ch 13 added