Preclinical Radio - Part II (Modified Techniques)

How is the film packet placed in relation to the tooth under investigation with the bisecting angle technique?

placed as close as possible

1 multiple choice option

How is the bisecting angle technique carried out?

- film packet placed as close as possible to tooth under investigation

- angle formed btw. long axis of tooth and long axis of film is assessed and mentally bisected

- tubehead positioned at right angle to bisecting line with central ray aimed through tooth apex

What are technical limitations of the bisecting angle technique?

- long axis of multi-rooted teeth isn't easily determined

- angulation of central ray to imagined line is arbitrary

What are diagnostic limitations of the bisecting angle technique?

- anatomic inaccuracy

- distortion and magnification are inherent

What is the head position for the bisecting angle technique?

occlusal plane of teeth of interest must be parallel to the floor

What is the film/sensor position for the bisecting angle technique?

- same guidelines used for paralleling

- extend edge of film several mms beyond the incisal edge/occlusal surface

What is the horizontal angulation for the bisecting angle technique?

- central ray is parallel to MR of teeth under investigation in order to achieve open contacts

- determined by shape of arch and position of teeth

What is the vertical angulation for the bisecting angle technique?

perpendicular to imaginary line bisecting the angle formed by long axis of the tooth and long axis of film

What are the instruments used for the modified technique with sensors?

- snap-a-ray Dentsply Rinn

- sticky tab system

What is horizontal angulation responsible for?

- controls radiation beam as it crosses the teeth and anatomy

- opens interproximal contacts

What is vertical angulation responsible for?

capturing areas of interest and surrounding bone

When is increased vertical angulation needed?

when imaging a long root for periapical diagnosis

Excessive vertical angulation results in ___

A) elongation

B) foreshortening

B) foreshortening

Insufficient vertical angulation results in ___

A) elongation

B) foreshortening

A) elongation

What are the 4 variables that must come together for quality images whether the operator is using an aiming system or not?

- head position

- receptor position

- vertical angulation

- horizontal angulation

What is the head position for modified techniques?

- occlusal plane must be parallel to the floor

- mid-sagittal plane vertical

head against headrest

- chair in upright position

For the modified technique, what should you do if the apices aren't visible?

lower occlusal plane and/or increase the (+) vertical angulation

What are technical limitations with the endo technique?

- endo procedures are technically challenging

- film/sensor and PID must be properly positioned to capture as ideal an image as possible of the apex

- presence of rubber dam, clamp, files, master cones

What are technique modifications for the endo technique?

- visualization of multiple roots

- increased vertical angulation

How do you visualize multiple roots in the endo technique?

- separate multiple roots/canals in order to assess

- vary horizontal angulation from normal by 10-15 degrees (usually in forward direction)

- SLOB rule

How should you vary vertical angulation in the endo technique?

vary vertical angulation 10-15 degrees beyond the recommended for the tooth

What are instruments used for the endo technique when using the modified technique?

- hemostat

- snap-a-ray

What are instruments used for the endo technique when doing paralleling?

XCP endo instruments

Where is the sticky tab located on the sensor when doing the endo technique?

- attached to infection control barrier

- positioned across the corner of the sensor to draw out of the mouth

How do you separate files when imaging endo?

change horizontal angulation

1 multiple choice option

How do you get the periapical region of the tooth when imaging endo?

change vertical angulation

1 multiple choice option

What is the theory for the occlusal technique?

- displays a relatively large segment of a dental arch on one intraoral film

- useful when patients can't tolerate traditional PA technique

- can be used in combination w/ traditional PAs for localization purposes

What are the purposes of the occlusal technique?

- precisely locates roots and supernumerary, unerupted, and impacted teeth

- localizes foreign bodies in the jaws and stones in ducts of sublingual and submandibular glands

- demonstrate and evaluate integrity of anterior, medial, and lateral outlines of maxillary sinus

- aids in examination of patients w/ trismus

- obtain info about location, nature, extent, and displacement of fractures of mandible and maxilla

- determines medial and lateral extent of diseases and to detect disease in the palate or floor of the mouth

What are instruments used for the occlusal technique with film?

none

What are the instruments used for the occlusal technique with sensors?

some type of holder

For the occlusal technique, size ___ is used for adults

A) 1

B) 2

C) 3

D) 4

D) 4

For the occlusal technique, size ___ is used for peds

A) 1

B) 2

C) 3

D) 4

B) 2

What is the image field for the maxillary anterior modified occlusal technique?

- anterior maxilla

- canine to canine

- anterior floor of nasal fossa

- nasopalatine foramen

What is the vertical angulation for the maxillary anterior modified occlusal technique?

+60

3 multiple choice options

What is the horizontal angulation for the maxillary anterior modified occlusal technique?

parallel with marginal ridges of teeth of interest

What are indications of the maxillary occlusal technique?

- PA assessment of incisors

- useful in adults and children unable to tolerate PA film/sensor placement

- detection and localization of unerupted and supernumerary teeth

- evaluation of size and extent of pathological lesions in anterior maxilla (cysts, tumors, PA inflammatory lesions)

- assessment of fractures of teeth and alveolar bone

What is the image field for the mandibular anterior modified occlusal technique?

anterior mandible, dentition, and alveolar bone from canine to canine

What is the vertical angulation for the mandibular anterior modified occlusal technique?

-50

3 multiple choice options

What are indications of the mandibular occlusal technique?

- PA assessment of the incisors

- useful in adults and children unable to tolerate traditional PA placement

- detection and localization of unerupted and supernumerary teeth

- evaluation of size and extent of pathological lesions in the anterior mandible (cysts, tumors, PA inflammatory lesions)

- assessment of fractures of teeth and alveolar bone

What is the image field for the maxillary posterior modified oblique occlusal technique?

- posterior maxilla

- dentition distal canine through 3rd molar

- antrum

- distal tuberosity

- zygomatic process

What is the vertical angulation for the maxillary posterior modified oblique occlusal technique?

+60

3 multiple choice options

What are indications of the maxillary posterior occlusal technique?

- PA assessment of posteriors

- detection and localization of unerupted and supernumerary teeth

- evaluation of size and extent of pathological lesions in posterior maxilla (cysts, tumors, PA inflammatory lesions)

- assessment of antral floor

- assessment of fractures of teeth and assoc. alveolar bone including tuberosity

- assessment of roots pushed into antrum during extractions

What is the image field of the mandibular posterior occlusal technique?

- posterior mandible

- dentition distal canine through 3rd molar

- cortex of mandible

What is the vertical angulation for the mandibular posterior occlusal technique?

-50

3 multiple choice options

What are indications of the posterior mandible occlusal technique?

- PA assessment of the posteriors

- detection and localization of unerupted and supernumerary teeth

- evaluation of size and extend of pathological lesions of the posterior mandible (cysts, tumors, periapical inflammatory lesions)

- assessment of fractures of teeth and assoc. alveolar bone

What is the image field for the mandibular true occlusal?

- soft tissues of floor of mouth

- buccal and lingual cortical plates

- dentition and its position in mandible

What is the head position for the mandibular true occlusal?

- patient reclined

- extend neck is possible

What is the vertical angulation of the mandibular true occlusal?

-90

3 multiple choice options

What are the indications for the mandibular true occlusal?

- detection of RO calculi in submandibular and sublingual salivary ducts

- assessment of BL position of unerupted/impacted teeth

- assessment of BL expansion of body of the mandible (cysts, tumors)

- assessment of displacement fractures of the anterior body of mandible in horizontal plane

- assessment of mandibular tori

The number and type of films is based on what?

- age

- medical history

- general oral health

- caries (past and present)

True/False: the AAOMR requires the use of aprons when taking x-rays

False

What are instruments used when taking peds x-rays without an aiming ring?

- snap-a-ray

- sticky tabs for posterior PAs

- paper tabs or sticky tabs

What are instruments used when taking peds x-rays when paralleling?

Rinn XCP instruments if age appropriate

What is the 8 film series for peds?

- 2 anterior occlusals

- 2 posterior bitewings

- 4 posterior periapicals

What are the occlusals and bitewings taken for peds (where and how many)?

- 2 anterior occlusals

- 2 posterior bitewings

True/False: for peds, you should increase the number of images as the child gets older and the mouth gets bigger

True

What size films are being used for a peds patient with primary teeth present only?

- size 0 for posterior bitewings and PAs

- size 2 for anterior occlusals

What size films are being used for a peds patient with mixed dentition (with 1st permanent molars)?

- size 1 for posterior bitewings and PAs

- size 2 for anterior occlusals

What size films are being used for a peds patient with mixed dentition including 1st permanent molars and premolars?

- size 2 for posterior bitewings and PAs

- individualized film selection for anterior PAs

What is the image field for pediatric maxillary anterior modified occlusals?

- anterior maxilla

- canine to canine

What is the vertical angulation for peds maxillary anterior modified occlusals?

+60

3 multiple choice options

What are the indications for peds maxillary anterior modified occlusals?

- caries detection

- assessment of development

What is the image field for peds mandibular anterior modified occlusals?

- anterior mandible

- canine to canine

What is the vertical angulation for peds mandibular modified occlusals?

-50

3 multiple choice options

What are the indications for peds mandibular modified occlusals?

- caries detection

- assessment of development

What is the vertical angulation for peds maxillary posterior PAs?

+5 to +10

What is the horizontal angulation for peds maxillary and mandibular posterior PAs?

positioned to open and visualize interproximal contacts

What is the vertical angulation for peds mandibular PAs?

0 to -5

What are instruments used for peds bitewings?

- paper bite tab

- sticky bite tabs

What is the vertical angulation for peds bitewings?

0 to +5

What is the film/sensor positioning for peds bitewings?

- captures distal 1/3 to 1/2 of maxillary and mandibular canine crowns

- front edge positioned toward midline and advanced as far forward as arch will allow

What is the priority list for interproximal contacts in the mixed dentition?

1. age of patient

2. which teeth have been erupted the longest?

3. which teeth will hopefully a last lifetime?

What are purposes of bitewings?

- detection of interproximal caries

- detection of secondary caries

- evaluation of periodontal alveolar crest levels

- evaluation of interproximal calculus

- evaluation of peri-implant bone levels

What is the vertical angulation for bitewings?

+5 to +10 across occlusal plane

What are instruments used for bitewings when using film?

- sticky tab

- paper tabs

- dentsply Rinn XCP instruments

What are instruments used for bitewings when using sensors?

- sticky tab

- Dentsply Rinn XCP horizontal and vertical

What is the placement/horizontal angulation for an anterior vertical BW?

- receptor centered on canines, central incisors

- focused on interproximal contacts

- mesial of canines and all incisors if possible

What is the placement/horizontal angulation for a posterior vertical BW for premolars?

- positioned to capture distal 1/2 to 1/3 of maxillary and mandibular crowns

- opens appropriate contacts

What is the placement/horizontal angulation for posterior vertical BW for molars?

- positioned to capture the distal of the most distal maxillary and mandibular crowns

- opens appropriate contacts

What is the film size for adults for the anterior vertical BW?

size 1

How many images are taken for anterior vertical BWs?

A) 1

B) 2

C) 3

D) 4

C) 3

What is the image size for posterior vertical BWs?

2

How many posterior vertical BWs are taken on each side?

A) 1

B) 2

C) 3

D) 4

B) 2

What is the selection/orientation for a posterior vertical holder used to create a PA?

- vertical orientation

- film/sensor is offset to align with the teeth/tooth

What is the purpose of a posterior vertical holder used to create a PA?

- creates ideal PA as films/sensor is forced to stay in mouth and parallel to long axis of tooth/teeth

- appropriate PID vertical angulation is used (aiming ring not followed)

What is the size of film used for implants?

2

What is the sensor placement/PID placement/vertical angulation for implants?

regardless of technique, PIDs vertical angulation parallels implant platform

What are radiographs used for with implants?

- implant placement

- seating of healing abutment

- seating of impression coping

- seating of abutment/crown

For bitewings taken pre-cementation, where is cotton placed?

directly on top of crown

Why is cotton placed directly over the top of the crown when taking bitewings pre-cementation?

provides even pressure on the crown to verify seating, closed margins, and contacts

What are advantages of the bisected angle technique?

- positioning of the film packet is reasonably comfortable for the patient in all areas of the mouth

- positioning is relatively simple and quick

- if all angulations are assessed correctly, the image of the tooth will be the same length as the tooth itself and should be adequate for most diagnostic purposes

What are disadvantages of the bisected angle technique?

- many variables involved in this technique often result in the image being badly distorted

- incorrect vertical angulation will result in foreshortening or elongation of the image

- periodontal bone levels are poorly shown

- shadow of zygomatic buttress frequently overlies the roots of the upper molars

- horizontal and vertical angles have to be assessed for every patient and considerable skill is required

- it is not possible to obtain reproducible views

- coning off/cone cutting may result if the central ray is not aimed at the center of the film, particularly is using rectangular collimation

- incorrect horizontal angulation will result in overlapping of the crowns and roots

- crowns of teeth are often distorted, thus preventing detection of approximal caries

- buccal roots of maxillary premolars and molars are foreshortened

A 28-year-old patient presents for routine dental radiographs. The clinician decides to use the paralleling technique instead of the bisecting angle technique to obtain periapical images.

Which of the following best describes a primary advantage of the paralleling technique over the bisecting angle technique?

A. Allows shorter exposure times due to closer placement of the sensor

B. Reduces vertical distortion by aligning the X-ray beam perpendicular to the receptor and tooth

C. Requires less patient cooperation and sensor stabilization

D. Is better suited for patients with small mouths or shallow palates

B. Reduces vertical distortion by aligning the X-ray beam perpendicular to the receptor and tooth

A 67-year-old patient presents for a full-mouth series. Due to a shallow palate and difficulty tolerating the positioning of the film holder, the clinician decides to use the bisecting angle technique instead of the paralleling technique.

Which of the following is the most appropriate justification for using the bisecting angle technique in this patient?

A. It eliminates the risk of elongation and foreshortening

B. It requires less radiation exposure to obtain the same diagnostic quality

C. It is better tolerated by patients with anatomical limitations such as shallow palates or small mouths

D. It provides more consistent and reproducible results than the paralleling technique

C. It is better tolerated by patients with anatomical limitations such as shallow palates or small mouths

A 35-year-old patient is undergoing a full mouth series of radiographs. While reviewing the periapical image of tooth #8, you notice that the image is foreshortened, with the crown appearing disproportionately short and the apex not fully visible. What is the most appropriate adjustment to correct this error?

A. Increase the horizontal angulation

B. Decrease the horizontal angulation

C. Shift the X-ray tubehead more posteriorly

D. Decrease the vertical angulation

E. Increase the vertical angulation

F. Use a shorter exposure time

D. Decrease the vertical angulation

During a routine periapical radiograph of tooth #9, the image reveals that the tooth appears longer than normal, with the root apex extending beyond the film. Which adjustment should be made to correct the elongation in the next attempt?

A. Increase the horizontal angulation

B. Decrease the horizontal angulation

C. Increase the vertical angulation

D. Decrease the vertical angulation

E. Use a film holder with a longer bite block

F. Move the X-ray tubehead closer to the patient

C. Increase the vertical angulation

A 6-year-old patient presents with delayed eruption of the maxillary central incisors. Clinical examination reveals mild soft tissue swelling, and the teeth are not visible in the arch. Which radiographic technique is most appropriate to assess the presence and position of the unerupted maxillary anterior teeth?

A. Periapical radiograph using paralleling technique

B. Panoramic radiograph

C. Modified maxillary anterior occlusal radiograph

D. Bitewing radiograph

C. Modified maxillary anterior occlusal radiograph

A 42-year-old patient requires periapical radiographs of the anterior maxillary teeth. The clinician uses the bisected angle technique instead of the paralleling technique. Which of the following is a major technical limitation of this approach?

A. Requires a film holder with an aiming ring

B. Increased risk of image distortion due to angulation errors

C. Always requires a digital sensor

D. Cannot be used in edentulous areas

B. Increased risk of image distortion due to angulation errors

A 25-year-old patient presents with a suspected periapical abscess in the mandibular right first molar. To determine the direction of the lesion in relation to the root canal system, you take two periapical radiographs at different horizontal angles, the second moving the PID forward. You discover on the second image, that the lesion also moves forward. Using the SLOB rule, what is the likely location of this lesion?

A) The lesion is located on the lingual side of the root

B) The lesion is located on the buccal side of the root

A) The lesion is located on the lingual side of the root

A 40-year-old patient presents with a suspected periapical abscess in the maxillary left second molar. To determine the direction of the lesion in relation to the root canal system, you take two periapical radiographs at different horizontal angles, the second moving the PID forward. You discover on the second image, that the lesion seems to have moved in the opposite direction of the PID (more posterior). Using the SLOB rule, what is the likely location of this lesion?

A) The lesion is located on the lingual side of the root

B) The lesion is located on the buccal side of the root

B) The lesion is located on the buccal side of the root