Das 135: Intraoral And Extraoral Imaging(Chpt.39,40,41,42)

The number of bitewing films needed is determined by the number of teeth present in the posterior areas. Bitewing films are used to capture images of the back teeth, specifically the premolars and molars. By assessing the number of teeth in these areas, the dentist can determine how many bitewing films are necessary to accurately diagnose and monitor dental conditions such as cavities or gum disease. The other factors mentioned, such as the age of the patient, size of the patient's mouth, and number of periapical x-rays taken, may influence the overall treatment plan but are not directly related to the number of bitewing films needed.

The bisecting technique may be used in some situations such as a small mouth, shallow palate, or the presence of tori. This technique involves aligning the film and the long axis of the tooth, and then angling the x-ray beam to bisect the angle formed by the film and the tooth. It is commonly used when it is difficult to place the film parallel to the tooth due to anatomical limitations.

When the patient's tongue is not in contact with the palate during the exposure, it can cause a dark radiolucent shadow to obscure the apices of the maxillary teeth. This is because the tongue acts as a barrier and prevents the x-ray beam from fully penetrating the area, resulting in a shadow.

EndoRay is the correct answer because it is a film holder specifically designed for endodontic procedures. It aids in positioning the film by fitting around the dam clamp and the endodontic instruments. This ensures accurate and stable placement of the film, allowing for precise imaging during the procedure. XCP and EeZee-Grip are also film holders commonly used in dentistry, but they do not have the specific design features to accommodate endodontic instruments. Stable bite block is not a film holder and therefore not relevant to the question.

When taking radiographs using film, the white side of the film is always placed toward the teeth. This is because the white side of the film is the side that is sensitive to radiation and needs to be exposed to the X-rays. Placing the white side toward the teeth ensures that the X-rays pass through the teeth and interact with the film, creating an image of the teeth on the film. Placing the white side away from the teeth would result in an incorrect exposure and a poor quality radiograph.

In panoramic imaging, both the film/sensor and the tubehead rotate. This is because panoramic imaging requires capturing a wide-angle image of the entire dental arch, including both the upper and lower jaws. By rotating both the film/sensor and the tubehead, a continuous image can be obtained as the X-ray beam moves around the patient's head. This rotation allows for a more comprehensive and accurate panoramic image to be captured.

A periapical view is an X-ray that shows the entire tooth, from the occlusal surface or incisal edge to the bone about 2 to 3 mm beyond the apex. This view is used to assess the root and surrounding bone structure for any abnormalities or pathology. It provides a comprehensive image of the tooth and the surrounding bone, allowing for a thorough evaluation of the tooth's health.

The bisecting technique is used when patients have small mouths or low palatal vaults. This technique allows for better positioning of the sensor or film in these cases, ensuring that the entire area of interest is captured in the image. It helps to overcome the limitations posed by anatomical variations and provides a clear and accurate image.

The lead plate in the panoramic tubehead with an opening shaped like a narrow vertical slit is the collimator. A collimator is a device that restricts the size and shape of the X-ray beam, ensuring that only the desired area is exposed to radiation. In this case, the narrow vertical slit helps to shape the X-ray beam into a thin, focused line, allowing for more precise imaging in panoramic radiography.

When the patient does not stand or sit with a straight spine, the cervical spine (located in the neck) will appear as a radiopacity in the center of the film. This means that the cervical spine will show up as a dense, white area on the X-ray, which can obscure the diagnostic information that the dentist is trying to see. This can make it difficult to accurately interpret the X-ray and identify any potential issues or abnormalities in the teeth or surrounding structures.

The correct answer is 4. In adults, a size 4 intraoral film is used for the occlusal technique. The occlusal technique is used to capture images of the entire arch of teeth and surrounding structures in a single film. Size 4 intraoral films are larger in size and can accommodate the entire arch comfortably, making them suitable for this technique in adults.

During a radiographic survey of edentulous ridges, the most commonly found condition is retained root tips. This refers to the situation where fragments of teeth roots remain in the jawbone after a tooth extraction. These root tips can cause discomfort, infection, or other complications if not properly addressed. Radiographic surveys are often performed to identify and assess any remaining root tips in order to plan appropriate treatment.

Skull radiography is most often used in oral surgery and orthodontics. This is because oral surgery often requires detailed imaging of the jaw and surrounding structures, which can be achieved through skull radiography. Similarly, orthodontics involves the assessment and treatment of dental and skeletal irregularities, and skull radiography can be helpful in evaluating the position and alignment of the teeth and jaws. Therefore, the combination of oral surgery and orthodontics is the most appropriate answer.

If the patient's chin is too high during the panoramic exposure, a "reverse smile line" will appear on the radiograph. This is because the positioning of the chin affects the alignment of the teeth and jaw on the radiograph. When the chin is too high, it causes an upward curvature of the smile line, resulting in a reverse smile line appearance on the radiograph. This can help in identifying the incorrect positioning of the chin during the exposure.

Four standard-sized films are recommended to make a full bitewing survey of the posterior teeth. Bitewing radiographs are commonly used in dentistry to detect cavities and monitor the health of the teeth and surrounding structures. By placing the films in specific positions in the mouth, a comprehensive view of the posterior teeth can be obtained. Using four films allows for a complete survey of the back teeth, ensuring that no areas are missed during the examination.

The American Academy of Oral and Maxillofacial Radiology recommends using the paralleling technique because it provides the most accurate image with the least amount of radiation exposure. This technique ensures that the film sensor is positioned parallel to the teeth, resulting in a highly accurate image. Additionally, by using this technique, the film sensor is placed closer to the teeth, reducing the chance of patient gagging. Therefore, both factors contribute to the recommendation of the paralleling technique for its accuracy and patient comfort while minimizing radiation exposure.

A thyroid collar is not used to protect the neck during film exposure in panoramic radiography.

The correct answer is angulation. Angulation refers to the alignment of the x-ray beam in the horizontal and vertical planes formed by the long axis of the teeth and the film sensor placement. It is important to have proper angulation in order to obtain accurate and clear dental x-ray images.

Three for the maxillary arch and three for the mandibular arch.

The bitewing view is a dental radiographic technique that shows both the whole tooth crown to apex and the surrounding bone, as well as the crestal bone. This view provides a comprehensive image of the tooth and its surrounding structures, allowing for a thorough evaluation of dental health and any potential issues.

Digital technology has allowed better resolution and the ability to show better details in panoramic units. With digital technology, images can be captured and displayed in high resolution, allowing for clearer and more detailed images of the patient's teeth and surrounding structures. This advancement in technology has improved the diagnostic capabilities of panoramic units, allowing for better detection and evaluation of dental issues.

A full mouth series typically refers to a set of X-rays that captures images of all the teeth in the mouth. Since the question specifies that the patient is a six-year-old, it is safe to assume that their mouth is smaller in size compared to an adult. Therefore, a smaller film size, such as #1, would be required to properly capture all the teeth in the mouth of a six-year-old patient.

When the patient's jaws are outside the focal trough, the resulting images are distorted. This is because the focal trough is the region where the X-ray beam is focused, and if the patient's jaws are not properly aligned within this region, the X-ray image will appear distorted. The distortion can make it difficult to accurately assess the patient's dental structure and may require retakes to obtain clear and accurate images.

The question is asking about the size of the film sensor used for the anterior region of the mouth. The answer is either A or B because the size of the film sensor used in dentistry can vary depending on the specific dental procedure being performed.

When using the size #2 film sensor, the anterior films are positioned vertically and the posterior films/sensors are positioned horizontally.

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The CBCT is not difficult to learn to use and does not require a lot of practice.

The term that describes the imaginary line between the long axis of the tooth and the film plane is called the bisector. The bisector divides the angle formed by the long axis of the tooth and the film plane into two equal parts. This line is important in dental radiography as it helps in positioning the film accurately and obtaining clear and accurate images of the tooth.

The bisecting-angle instrument (BAI) uses aiming rings to determine the correct PID angulation. Aiming rings are commonly used in dental radiography to guide the positioning of the X-ray tube and ensure accurate angulation. By aligning the aiming rings with the desired angle, the dental professional can position the X-ray tube in the correct position to capture clear and accurate images.

When taking periapical x-rays, the patient's head is positioned upright for maxillary films and tilted back slightly for the mandibular arch. This positioning allows for optimal visualization of the teeth and surrounding structures in each arch.

The labial mounting method refers to the placement of dental films in the mouth so that the front side of the teeth (labial surface) faces the viewer. This method allows for easier identification and interpretation of dental structures and abnormalities. Mounting films according to the labial mounting method is recommended by the American Dental Association to ensure accurate diagnosis and treatment planning.

If a patient wearing earrings or glasses does not remove them before a panoramic x-ray image exposure, it can result in a blurred area or a ghost image appearing on the image. The earrings or glasses can obstruct the x-ray beam, causing a dark area or a blurred area on the image. Additionally, the reflection of the earrings or glasses can create a ghost image, which appears as a faint duplicate image on the x-ray. Therefore, both options B and C are correct.

To correct an elongated image on an x-ray view, the vertical angulation needs to be increased. This means that the angle between the x-ray beam and the object being imaged needs to be increased. By doing so, the image will appear shorter and more proportionate. Decreasing or lowering the vertical angulation would only exacerbate the elongation, while flattening the angulation would result in a distorted image. Therefore, increasing the vertical angulation is the correct adjustment to correct the elongation.

The phrase "appear on the same side as the original object" is not consistent with the production of panoramic ghost images. Panoramic ghost images typically appear on the opposite side of the original object, creating a mirrored effect.

The correct answer states that if it is not possible to obtain intraoral images, extraoral images must be used. This means that if the patient cannot tolerate having the film sensor placed in their mouth due to a gag reflex, alternative imaging techniques that do not require placing the sensor in the mouth should be used. This could include using extraoral techniques such as panoramic radiographs or cone beam computed tomography (CBCT) scans to capture images of the patient's oral structures.

When the patient's midsagittal plane is not centered, the structures on one side of the image appear narrower while the structures on the other side appear wider. This is because the misalignment causes a distortion in the image, making it appear asymmetrical.

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The angulation of the PID (Position-Indicating Device) is critical to ensure that the central ray is perpendicular to the bisector line in both the bisecting technique and the bitewing technique. In the bisecting technique, the PID is angled to achieve the correct alignment between the central ray and the bisector line of the angle formed by the tooth and the film. In the bitewing technique, the PID is also angled to ensure that the central ray is perpendicular to the bisector line of the interproximal spaces being examined.

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When using a size #1 film sensor for anterior images using the paralleling technique, four maxillary images and three mandibular images are exposed.

The main components of the panoramic unit include the x-ray tubehead, which generates the x-rays, and the head positioner, which holds the patient's head in the correct position for imaging. The x-ray tubehead is responsible for producing the x-rays that pass through the patient's head and create the panoramic image. The head positioner ensures that the patient's head is properly aligned and stable during the imaging process.

Occlusal radiographs are used to view the entire arch of teeth in either the maxilla or mandible. The radiographic film is placed on the occlusal surface of the teeth, and the patient bites down to hold it in place. The x-ray beam is directed perpendicular to the film and passes through the teeth and surrounding structures. In the case of a maxillary occlusal radiograph, the x-ray beam is most likely to pass through the bridge of the nose, as the film is positioned in the roof of the mouth.

The focal trough is a predetermined layer of structures that is sometimes referred to as the image layer. It is located between the film cassette and x-ray source. However, the statement that the trough is narrower in the posterior and wider in the anterior is not accurate. The focal trough is actually narrower in the anterior and wider in the posterior.

Rough handling of the film cassette during panoramic film unloading and reloading can cause static electricity to build up. This static electricity can result in black branch-like artifacts on the film, which are known as static electricity images.

A dark radiolucent shadow that obscures the anterior teeth can occur when the lips are not closed on the bite-block during the exposure. This can result in scattered radiation reaching the film, causing a dark shadow to appear on the radiograph.

An error in horizontal angulation is most likely to reduce the usefulness of an interproximal radiograph. Horizontal angulation refers to the alignment of the x-ray beam parallel to the interproximal spaces. If there is an error in horizontal angulation, the resulting radiograph may not accurately show the interproximal areas, making it less useful for diagnosing dental conditions such as cavities or periodontal disease in between teeth.

When taking an X-ray, positioning the film parallel to the long axis of the tooth helps to minimize image distortion. This is because when the film is parallel to the long axis, it aligns with the tooth structure and allows for a more accurate representation of the tooth's shape and size on the X-ray image. If the film is positioned perpendicular to the long axis, it can result in distortion and an inaccurate representation of the tooth. Similarly, the direction of the central ray of the X-ray beam does not affect image distortion, so the other options are incorrect.

If the patient's teeth are not positioned in the groove of the bite-block, they will appear "skinny". This is because the bite-block is designed to hold the teeth in a specific position and alignment, and if the teeth are not properly positioned within the groove, they will appear narrower or "skinny" compared to their actual size.

Occlusal radiographs are X-rays that provide a comprehensive view of the upper and lower teeth and their supporting structures. They are commonly used to locate unerupted teeth, which are teeth that have not yet emerged through the gums. By using occlusal radiographs, dentists can identify the position and orientation of unerupted teeth, helping them to plan for their extraction or to monitor their development. This type of radiograph is not typically used for detecting decay, checking bone levels, or identifying infections at the apex of the teeth.

The advantages of panoramic imaging, when contrasted with intraoral imaging, include less radiation exposure. This means that panoramic imaging exposes the patient to lower levels of radiation compared to intraoral imaging. This is advantageous as it reduces the potential risks associated with radiation exposure, making panoramic imaging a safer option for patients.

Panoramic radiographs are recommended in all of the listed clinical situations except for the evaluation of periodontal furcation involvement. Panoramic radiographs are useful for evaluating the mixed dentition, examining edentulous alveolar ridges, and assessing the development and position of third molar teeth. However, they may not provide sufficient detail for evaluating periodontal furcation involvement, which typically requires more specific imaging techniques such as periapical or bitewing radiographs.

In the paralleling technique, the central ray of the x-ray beam must be perpendicular to the film sensor and the long axis of the tooth. This means that the x-ray beam should be directed straight at a 90-degree angle to both the film sensor and the tooth. This positioning ensures that the x-ray image captured is accurate and provides a clear view of the tooth and its surrounding structures.

The correct answer is "The film sensor must be placed directly against the teeth being exposed." This statement is false because in the paralleling technique, the film sensor is placed away from the teeth being exposed. It is positioned parallel to the teeth and held in place by a holder, which helps to achieve accurate and consistent x-rays. Placing the film sensor directly against the teeth would lead to distorted images and inaccurate diagnosis.

The production of a wedge-shaped radiopaque artifact near the midline in panoramic radiography would be caused by the lead apron being placed too high up on the back of the patient's neck.

The given statement is not true because the digital panoramic unit does not use film that needs to be processed. Digital panoramic units use electronic sensors to capture and produce images instantly without the need for film processing.

In the paralleling technique of intraoral radiography, a focal spot distance of 12 inches/30 cm or more is advocated. This means that the distance between the x-ray tube and the image receptor should be at least 12 inches/30 cm. This distance is recommended because it helps to minimize image distortion and magnification, resulting in more accurate and clear radiographic images. Additionally, a longer focal spot distance reduces the risk of cone-cutting, where the x-ray beam does not fully cover the image receptor.

An accurate description of intensifying screens is that they are located on the internal surfaces of an open film cassette, composed of phosphor crystals that fluoresce upon x-ray exposure, and film size and sensitivity is paired with screen size and fluorescence. However, the reflecting layer does not direct the light produced toward the screen base.

An occlusal survey is not indicated to reveal the extent of periodontal lesions because it primarily focuses on determining the shape of the dental arch, locating the position of an impacted canine, and revealing fractures. Periodontal lesions involve the gums and supporting structures of the teeth, which can be assessed through other diagnostic methods such as periodontal probing and radiographs. Therefore, an occlusal survey is not necessary for this purpose.

The panoramic tubehead does not rotate the film behind the patient's head. Instead, it rotates behind the patient's head. The tubehead houses the filament that produces electrons and the target that produces radiographs. The vertical angulation of the tubehead is not adjustable.

With the paralleling technique, usually there are 8 posterior film sensor images taken. This technique involves placing the film or sensor parallel to the long axis of the tooth being examined. By taking images from different angles, it allows for a more comprehensive view of the posterior teeth. This technique is commonly used in dental radiography to accurately diagnose dental conditions and plan treatments.

The mandibular parasymphyseal area is the best region to examine to assess adequate density when determining ideal panoramic film density. This area is located in the anterior region of the mandible, near the midline. It is an area where the bone density is relatively uniform and less prone to anatomical variations. Therefore, it provides a good reference point to evaluate the overall density of the panoramic film. The other options mentioned, such as the dentinoenamel junction on molars, maxillary sinus cavity anatomy, and gonial angle of the mandible, may have more variations in density and are not as reliable for assessing overall density.

When taking radiographs on larger than average patients, the factor that would most likely be increased is time. This is because larger patients may require more time for the X-ray beam to penetrate through their body and reach the image receptor. Increasing the exposure time ensures that an adequate amount of radiation is delivered to produce a diagnostic image. Increasing other factors such as mA or kVp may result in overexposure for larger patients, while distance and filtration are not directly related to the size of the patient.

A panoramic image allows dentists to view the entire dentition and related structures on film. This means that they can see all of the teeth, as well as the surrounding bones, joints, and tissues. This provides a comprehensive view of the patient's oral health and helps in diagnosing and treating various dental conditions. It is an important tool in dentistry for evaluating the overall dental and oral health of a patient.

When the patient's head is positioned too far backward, the clinician will observe the following manifestations: the image is too large and does not fit on the film, anterior teeth on both arches are involved most often, and structures appear wider and very blurred compared to normal. However, the structures on one side will not be narrower than the other.