LO 7/8 Flashcards
What are the types of intraoral imaging examinations?
- Periapical examination
- Interproximal examination
- Occlusal examination
Describe periapical examinations
- Purpose - used to examine the entire tooth and supporting bone
- Type of imaging receptor - periapical receptor
- Technique - paralleling or bisecting
Describe interproximal examinations
- Purpose- to examine the crown of both the maxillary and mandibular teeth on a single film
- Type of imaging receptor - bitewing receptor
- Technique-bitwing technique
Describe occlusal examinations
- Purpose- used to examine large areas of the maxilla or the mandible on one film
- Type of imaging receptor - occlusal receptor
- Technique - occlusal technique (only bisecting can be used)
Describe a complete mouth series (CMS)
- Also known as full mouth series (FMS or FMX)
- Includes tooth fairing areas - dentulous areas, endentulous areas
Describe diagnostic criteria for intraoral images
- Images must have optimum density, contrast, definition, and detail
- Images must have the least amount of distortion possible
- The CMS must include images that show all tooth bearing areas
- Periapical images must show the entire crowns and roots of teeth being examined, as well as 2 to 3 mm beyond the root apices
- Bite-wing images must show open contacts
Describe an extraoral imaging examination
- An inspection of large areas of the skull or Jaws
- Extra oral receptors are receptors that are placed outside of the mouth
- Examples of common extra oral images - panoramic images, lateral jaw, lateral cephalometric, posteroanterior, Waters (assess perineal sinuses, nose, and cheekbones)
Not all patients need a complete mouth series, when is a complete mouth series appropriate?
- When a new adult patient presents with clinical evidence of generalized dental disease or history of extensive dental treatment
- Otherwise, a combination of bitewings, selected periapicals, and/or a panoramic image should be prescribed on the basis of a patient’s individual needs
______ is an imaginary line that divides the tooth longitudinally into two equal halves
Long axis of the tooth
_______ is the central portion of the primary beam of x radiation
Central Ray
What is the paralleling technique also known as?
- Extension cone paralleling technique
- Right angle technique
- Long cone (16 inch) technique
Describe the principles of the paralleling technique
- The receptor is placed in the mouth parallel to the long axis of the tooth being radiographed
- The central Ray of the X-ray beam is directed perpendicular to the film and 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
How do you achieve parallelism in the paralleling technique?
- The film must be placed away from the tooth and toward the middle of the oral cavity due to the curvature of the palate
- The object film distance must be increased to keep the film parallel with the long axis of the tooth
- Results in increased image magnification
What is a film holder / beam alignment device
A device used to position an intraoral film in the mouth and retain the film in position during exposure
______ results from excessive vertical angulation semicolon occurs of the central Ray is directed perpendicular to the plane of the film rather than to the imaginary bisector
Foreshortened images
______ results from insufficient vertical angulation; occurs if the central Ray is directed perpendicular to the long axis of the tooth rather than the imaginary bisector
Elongated images
Describe horizontal angulation
- Remains the same for paralleling, bisecting, and bite-wing techniques
- Correct horizontal angulation - the central rate is directed perpendicular to the curvature of the arch and through the contact areas of the teeth
- Incorrect horizontal angulation - overlapped contact areas
Where is a size 1 receptor used?
- In the interior region
- Long portion in the vertical direction
Where is the size 2 receptor used?
- Used in the posterior region
- Long portion in the horizontal direction
Describe patient preparation procedure for radiographs
- Explain the procedure to the patient
- Adjust the chair height to your (clinician) level
- Place and secure the lead apron
- Remove all objects from the mouth
Describe equipment preparation for radiographs
- Set the exposure control factors
- Open the sterilized package containing the beam alignment devices, and assemble the devices over a covered work area
Describe the exposures for anterior teeth
- Size 1 receptor is small and easier for a patient to tolerate (less likely to cause a patient to gag)
- A total of seven interior placements using the size one receptor - four maxillary exposures; 3 mandibular exposures
Describe posterior exposure placements
8 posterior placements - 4 maxillary exposures; 4 mandibular exposures
Describe receptor placement for paralleling technique
- The specific area where the receptor must be positioned before the exposure is dictated by teeth and surrounding structures
- The specific placements described in the chapter are for 15 receptor periapical series using size 1 receptors for anterior exposures and size to receptors for posterior exposures
Which section of the mouth is exposed first?
- Interior teeth followed by posterior teeth
What can a failure to send her the X-ray beam result in?
- A partial image or a cone-cut
When would you need to make modifications in the paralleling technique?
- Patient has a shallow palate or bony growths
- In the mandibular premolar region
What modification can be done if the patient has a shallow palate?
- Cotton rolls - two cotton rolls can be used, one placed on each side of the bite Block
- Vertical angulation - the vertical angulation can be increased by 5 to 15°
What modifications can be made if the patient has bony growths?
- Maxillary Torus - the film must be placed on the far side of the Taurus and then exposed
- Mandibular tori - the film must be placed between the tori and the tongue and then exposed
What modification needs to be done in the mandibular premolar region?
- Receptor placement - the receptor must be placed under the tongue
- Film - the lower edge of the film can be gently softened to prevent discomfort
The issue in this region is damaged to the patient’s sensitive tissue on floor of mouth
What are the advantages of the paralleling technique?
- Accuracy - the image is free of distortion
- Simplicity - it eliminates the need to determine the horizontal and vertical angulation, it eliminates chances of dimensional distortion
- Duplication - comparison of serial images has great validity
What are the disadvantages of the paralleling technique?
- Receptor placement - may be difficult
- Patient discomfort - beam alignment device may cause discomfort
Give a brief overview of the bisecting technique
- The film must be placed along the lingual surface of the tooth
- The plane of the film and the long axis of the tooth form an angle at a point where the film contacts the tooth
- The imaginary bisector bisects the angle formed by the film and long axis of the tooth
- The central Ray is directed perpendicular to the imaginary bisector
- The two imaginary triangles that result are right triangles and congruent
What are the basic rules of the bisecting technique?
- Film stabilization - can use film holders or finger holding method
- Size 2 film is used
- Horizontal angulation - is the same for paralleling, bisecting, and bite-wing technique; directed through the contact areas between the teeth
- Vertical angulation - the central Ray is directed perpendicular to the imaginary bisector - for shortening and elongation can result
Describe beam alignment devices
- Devices used to position an intraoral receptor
- Aiming rings allow for easy alignment of the position indicating device
- Recommended because they eliminate the need for patient to stabilize the receptor
- Rinn BAI system
Describe receptor holders
- Used to position the receptor in the mouth and maintain it in a position during exposure
- Stabe bite Block
- Rinn Snap-A-Ray Holder
What is the receptor typically used in the bisecting technique?
- Size 2 receptor
Anterior- long portion in a vertical direction
Posterior - long portion in a horizontal direction
What are the rules for the bisecting technique?
- Film placement - occlusal and extends 1/8 in beyond the incisal or occlusal surfaces
- Exposure order - start with interiors, then premolars, finally molars
Describe horizontal angulation
- The positioning of the tube head and the direction of the central Ray in a horizontal or side to side plane
- Correct horizontal angulation - the central Ray is directed perpendicular to the curvature of the arch and through the contact areas of the teeth
- Incorrect horizontal angulation - overlapped contact areas
Describe vertical angulation
- The positioning of the PID in a vertical or up and down plane
- Correct vertical angulation - results in a radiographic image that is the same length as the tooth
- Incorrect vertical angulation - results in a radiographic image that is not the same length as the tooth
______results from excessive vertical angulation
Four shortened images
______ results from insufficient vertical angulation
Elongated images
Describe the exposure sequence for anterior teeth
- Anterior exposure sequene - begin with a maxillary right canine tooth and end with the maxillary left canine
- Move to the mandibular Arch - begin with the mandibular left canine, expose all of the mandibular anterior teeth, finish with the mandibular right canine
Describe the exposure sequence for posterior teeth
- Begin with the maxillary right quadrant, move to the mandibular right quadrant, move to the maxillary left quadrant, finish with the mandibular left quadrant
- I each quadrant, expose the premolar receptor first and then the molar receptor
What are the advantages of the bisecting technique?
- Can be used without a film holder for clients with a shallow palette, bony growths, gag reflex etc
- Decreased exposure time with a short 8-in PID, which we use in clinic
What are the disadvantages to the bisecting technique?
- Image distortion - occurs when a short PID is used. The x-rays diverge more, resulting in image magnification
- Distortion occurs because structures that are further away from the film appear more elongated than those that are closer to the film
- Could be unnecessary exposure if the client tries to stabilize the film with their finger
Give a brief overview of a bite-wing examination
- Includes the crowns of the maxillary and mandibular teeth, the interproximal areas, and the areas of crestal bone on the same film
- Useful in detecting interproximal caries and examining the crestal levels of the bone
- Vertical angulation is typically 0°, horizontal angulation is typically through the contacts
What are vertical bitewings used for and how are they placed?
- They are used to examine the level of alveolar bone
- There a place with long portion of the film in a vertical direction
- Seven films are used to cover the canine, midline, premolar, and molar areas
What are the basic principles of the bitewing “technique”?
- The receptor is placed in the mouth parallel to the crowns of both the upper and lower teeth
- The receptor is stabilized when the patient bites on the bite wing tab or beam alignment device
- The central ray is directed through the contacts of the teeth, using a + 10° vertical angulation
Which receptor sizes are used for bitewings?
- Size 0 - for posterior teeth of children with primary dentitions
- Size 2 - for posterior teeth of older children and adults, place horizontally or vertically
- Size 3 - for bitewings, not recommended for adult patients
What is the difference between positive and negative vertical angulation?
- Positive angulation the PID is positioned above the occlusal plane and the central Ray is directed downward
- Negative angulation the PID is positioned below the occlusal plane in the central Ray is directed upward
What is the exposure sequence for bite wings and periapicals?
- Expose all interior periapical receptors first
- Follow with posterior periapical receptors
- Finish with bite wing exposures
What is the exposure sequence if you are doing bitewings only?
- Expose the premolar bitewing receptor first
- Expose the molar bite-wing receptor next
- Repeat on opposite side of the mouth
_____ are often used as post treatment or follow-up films for patients with bone loss caused by periodontal disease
Vertical bite wings
How can you modify a bite-wing radiograph when the patient has edentulous spaces?
- A cotton roll must be placed in the area of the missing tooth to support the bite-wing tab or beam alignment device
Describe the appearance, cause, and correction of unexposed receptors
- Can occur with digital sensors or films
- Appearance - the image appears clear
- Cause - failure to turn on the X-ray machine, electrical failure, malfunction of the X-ray machine
- Correction - make certain the X-ray machine is turned on and listen for the audible exposure signal
Describe the appearance, cause, and correction of film exposed to light
- Occurs in film only
- Appearance - the image appears black
- Cause - the film was exposed to white light
- Correction - do not unwrap in a room with white light, check the dark room for light leaks, turn off all lights in the dark room except the safelite
Describe the appearance, cause, and correction of overexposed receptors
- Me occur with digital sensors or film
- Appearance - image appears dark or high in density
- Cause - excessive exposure time, kilovoltage, or milliamperage
- Correction - check settings and reduce as needed before exposing receptor
Describe the appearance, cause, and correction for an underexposed receptor
- May occur with digital sensors or film
- Appearance - the image appears light or low density
- Cause - the receptor was underexposed
- Correction - check the exposure time, kill a voltage, and milliamperage settings on the X-ray machine before exposing your receptor
Describe the technique errors that occur with periapical views
- Receptor placement problems - may have absence of apical structure or dropped film corner
- Angulation problems- horizontal or vertical
- PID alignment problems- conecut with or without beam alignment device
Describes the appearance, cause, and correction for absence of apical structures on the radiograph
- May occur with digital sensors or film
- Appearance - no apices appear on the receptor
- Cause - receptor was not positioned in the patient’s mouth to cover the apical regions of the teeth
- Correction - make certain no more than 1/8 in of the receptor edge extends beyond the incisal / occlusal surfaces of the teeth
Describe the appearance, cause, and correction for dropped receptor corner
- May occur with digital sensors or film
- Appearance - the occlusal plane appears tipped or tilted
- Cause - the edge of the receptor was not placed parallel to the incisal - occlusal surfaces of the teeth
- Correction - make certain the edge of the receptors please parallel to the incisal - occlusal surfaces of the teeth
Describe the technique, appearance, cause, and correction for foreshortened images
- May occur with digital sensors or film
- Technique - may occur with the bisecting technique when beam alignment device is not used
- Appearance - short teeth with blunted roots
- Causes the vertical angulation was insufficient
- Correction - use adequate vertical inculation with the bisecting technique
Describe position indicating device alignment problems
- If the PID is misaligned and the X-ray beam is not centered over the receptor, a partial image results
- A cone cut image appears as a clearer or white unexposed area on a dental image and may occur with a rectangular or round PID
Describe the technique, appearance, and correction for cone cut with a beam alignment device
- May occur with digital sensors or film
- Technique - may occur with either paralleling or bisecting technique when a beam alignment device is used
- Appearance - a clear area appears on the image
- Cause - the PID was not properly aligned with the periapical beam alignment device
- Correction make certain x-ray beam is centered over the receptor
Describe the technique, appearance, cause, and correction for incorrect receptor placement of premolar bite wing
- May occur with a digital sensor or film
- Technique - may occur with bite-wing technique when abim alignment device or bite tab is used
- Appearance - distal surfaces of the canine’s are not visible on the image
- Cause - the batwing was receptor was positioned to distally in the mouth
- Correction - make certain the interior edge of the bite wing receptor is positioned at the mesially of the mandibular canine
Describe the technique, appearance, cause, and correction for incorrect placement of molar bite wing
- Me occur with digital sensors or film
- Technique - may occur with the bite wing technique when a beam alignment device or bite tab is used
- Appearance - third molar regions are not visible on the image
- The bite-wing receptor was positioned to mesially in the mouth
- Correction - makes certain the interior edge of the bite-wing receptor is positioned at the mesial line of the mandibular second premolar
Incorrect horizontal angulation results in ______, and incorrect vertical angulation results in ______
- Overlapped interproximal contacts
- Distorted images
Describe the technique, appearance, cause, and correction for bending of the receptor
- May occur with indirect digital sensors or film
- Technique - may occur with paralleling, bisecting, or bite-wing techniques
- Appearance stash images appear stretched on a film and distorted on PSP receptors
- Cause - improper handling; receptor damaged
- Correction check receptor placement before exposure
Describe the technique, appearance, cause, and correction for creasing on the receptor
- Make her with indirect digital sensors or film
- Technique Dash may occur with paralleling, bisecting, or bite-wing technique
- Appearance - a thin radio loosen line appears on the image
- Cause - improper handling semicolon receptor creased; film emulsion cracked
- Correction - do not over manipulate the receptor