Intra-Oral Radiographic Anatomy & Basic Interpretation Flashcards
When can carious lesions be detected radiographically?
when there has been enough demineralisation to differentiate the area from normal enamel and dentine
What is cervical burnout?
Triangular shaped radiolucency at the
neck of the teeth
Artefactual phenomenon created by the anatomy of the teeth and the varied penetration of the X-ray beam as a result of this
At contact points, less tooth to pass
through, less attenuation & therefore darker corresponding area on radiograph as more of the beam passes through
not secondary caries
What are misleading shadows?
Radiopaque zone beneath amalgam restorations
Consequence of Sn & Zn ions released into underlying demineralised dentine increasing its radiodensity→radiopaque zone→ normal dentine either side may appear more radiolucent in contrast
What is the mach band effect?
- Optical illusion caused by the retina
- Human visual system makes the bright areas look brighter, and dark look darker so as to enhance contrast and differentiate structures at their boundaries
How to differentiate between caries and mach band effect?
caries - jagged aread
mach band - uniform outlines around fillings
What are important features to note in bitewings?
- RADIOLUCENT AREAS – Caries v Cervical burnout
- RADIOPAQUE AREAS – Restorations
- PRESENCE OF ROOT FILLING MATERIAL
- PRESENCE/POSITION OF POSTS AND PINS
What are periapicals mainly used for?
Mainly used for detection of periapical radiolucencies and bone levels
What is the Y of Ennis?
- Radiographic Feature
- Superimposition of the nasal
cavity floor and the border of the maxillary sinus
above canines, upside down Y seen on maxillary canine periapicals
What are the 4 occlusal views?
Upper
1. Anterior oblique maxillary
2. Lateral oblique maxillary
Lower
1. True mandibular occlusal
2. Anterior oblique mandibular
At what angle is the x-ray beam at when at occusal maxillary anterior oblique is taken?
65
At what angle is the true occlusal mandibular taken?
90 degrees
to sensor
At what degree is an anterior oblique mandibular taken?
45 degrees
What is the aim of taking a radiograph?
- To identify the presence or absence of disease
- To provide information on the nature and extent of the disease
- To monitor disease such as caries progression or cyst recurrence
- To investigate unerupted/missing teeth when necessary
- To enable the formation of a differential diagnosis
What are the optimum viewing conditions?
- Subdued lighting conditions/low level of light
- Minimise or diminish screen glare (inappropriately placed lights)
- Utilise monitors with adequate resolution and brightness
What are the aspects to assess when determining the image quality?
- Foreshortening
- Elongation
- Overexposure/Underexposure (less troublesome with digital advances!)
- Coning off
- Receptor placed back to front… May not be aware with digital images
