Chapter 5: Intraoral Radiographic Imaging Flashcards
The 3 categories of radiographic imaging are?
BOP
- bitewing
- occlusal
- periapical
Bitewing projection?
Crowns of all teeth and adjacent alveolar crest
Occlusal projection?
Area of teeth and bone larger than Periapical
Periapical projection?
All of a tooth and the surrounding bone
Criteria of quality for intraoral radiographic imaging:
- Record the complete areas of interest
- Reduce the amount of distortion
- Optimal density and contrast
General steps of periapical projection technique:
- prepare the unit
- seat the patient: upright, lead apron
- adjust xray settings: ET, mA, kVp
- examine oral cavity
- position tube head and reception and X-ray tube
- make the exposure
What to expect from the periapical projection technique:
Teeth
Periodontal areas
Surrounding bone
Bone
Periapcial indications:
Assessment of the tooth and bone alterations
Study and location of bone areas
Implant assessment
What are the two techniques of periapical projection:
- bisecting angle and paralleling technique
Paralleling technique:
Film is parallel to the long axis of the tooth and the xray beam is perpendicular to the film and the long axis of the tooth
- Increase the distance between xray source and object to minimise the magnification of the image
Other names for the paralleling technique:
- mc cormack
- right angle
- long cone
RML
Advantages of the paralleling technique:
- less distortion
- high resolution
- high accuracy
HARAD
Closer to the area of interest, shorter cone, film is placed on the palate, patient will hold the film, form a triangle: these statements are referring to which periapical technique
Bisecting angle technique
The bisecting angle technique is also called:
- dieck
- cieszynski
- short cone
What is the bisecting angle technique based on?
Cieszynski’s rule of isometry: two triangles are equal if they share one complete side and have 2 equal angles
Where is the receptor positioned in the bisecting angle technique:
On the lingual surface of the teeth resting in the palate or floor of the mouth
Bisecting angle technique:
Long axis of the tooth and receptor form an angle and an imaginary line bisects that angle, and the xray beam is projected at a right angle to that bisecting line
Which of the 2 Periapical techniques is: most common, simple, has a higher deformation?
Bisecting angle technique
Positioning of the patient in the bisecting angle technique:
- comfortable, stable, leaning against the chair
- maxillary images: upright with sagittal plane vertical and occlusal horizontal
- mandibular images: tilted slightly to compensate for the change occlusal plane when mouth is open
Do you place the receptor in front of or behind the area of interest in the BAT?
Behind
Angulation of the tube head in the BAT?
- vertical angulation
- horizontal angulation
Vertical angulation: maxilla
Incisors: 40
Canines: 45
PM: 30
M: 25
CIPM
* remember for dental anatomy that canines have the most angulation in the dental arch
Vertical angulation: mandible
Incisors: -15
Canines: -20
PM: -10
M: -5
CIPM
Horizontal angulation:
Perpendicular to bisector
Advantages of Periapcial projection:
Non complex technique
Low cost
Sharpness
Disadvantages of Periapical technique
Limited area
Bidimensional image
Overlapping
Ineffective in edentulism
Which Radiographic technique is indicated for caries diagnosis?
Bitewing
Indications of bitewing projections:
- occlusal and inter proximal caries detection
- recurrent caries
- pulpal problems
- overflowing restorations
- fixed prosthesis adjustments
- enamel cementum junction
- alveolar crest
- Inter proximal calculus deposits
Positioning of the patient’s head in bite wing projection:
Occlusal plane parallel to the floor
Receptor placement in bitewing projection:
- dont bend
- comfortable position lingual to the teeth to be examined
- bitewing between occlusal surfaces
- posterior edge distal to 2nd molar
Vertical angulation of the bitewing projection
5-10 degrees palatal anatomy
Horizontal angulation of the bitewing projection:
Perpendicular to the dental arch
Which of the X-ray projection techniques uses a large receptor
Occlusal
Indications of occlusal projections:
- dental trauma in anterior teeth
- mandibular fracture
- foreign bodies
- impacted teeth
- cortical bone enlargement
- calculus in warton’s duct
- assessment of the buccal or lingual position of impacted teeth
Orthogonal projection: xray beam perpendicular to the
Film
Contraindications of xray projections?
- infection/trauma
- mental and physical disabilities
- gag reflex
- pregnancy
- edentulous patients
