Radiology Ch. 4 and 18

x-rays

cause biologic changes in living cells, adversely affects all living tissue

prescribing dental radiographs

This is based on the individual needs of the patient

FMX

Appropriate when a new adult patient presents with clinical evidence of generalized dental disease or history of extensive dental treatment

inherent filtration

Takes place when the primary beam passes through the glass window of the x-ray tube, the insulating oil, and the tubehead seal

inherent filtration

It does not meet the standards regulated by state and federal law

0.5-1.0 mm of aluminum

added filtration

An aluminum disk is placed between the collimator and tubehead seal

Filters low-energy and longer wavelength x-rays

total filtration

The sum of inherent and added filtration

Regulated by state and federal law

1.5 mm

Minimum total aluminum filtration for machines operating at 70kV or below

2.5 mm

Minimum total aluminum filtration for machines operating higher than 70kV

collimation

restricts the size and shape of the x-ray beam

round colliator

Located at the opening of the tubehead

Produces a cone-shaped beam 2.75 inches in diameter

rectangular collimator

Located at the opening of the tubehead

Exposes 60% less tissue than round option

PID

An extension of the x-ray tubehead used to direct the x-ray beam

Can be round or rectangular

16in rectangular

What is the recommended PID that is the most effective at reducing patient exposure

thyroid collar

A flexible lead shield placed around the patient’s neck

ONLY recommended for all intraoral exposures

lead apron

Placed over the patient’s chest and lap to protect the reproductive organs and blood forming tissues from scatter radiation

F-speed

Provides 20% more reduction exposure than E-speed

Kodiak InSight

beam alignment device

Stabilizes the receptor in the mouth and reduces the chance for movement

Eliminates the need for patient to hold receptor with a finger

60-80

What is the optimal kilovoltage setting

6-8

What is the optimal mliamperage setting

nondiagnostic images

must be retaken, resulting in additional radiation exposure for the patient

digital

Type of receptors that are most effective method of reducing a patient’s radiation exposure

primary beam

When taking radiographs, he dental radiographer must avoid the:

6 feet

The dental radiographer must maintain a distance of at least __ from the tubehead

inverse square law

The intensity of the beam diminishes as the distance from the source increases

90-135 degrees

What is the angle range the radiographer must be at in comparison to the beam

protective barriers

Leaded walls or lead doors that absorb the primary beam

film badge

Worn at waist level when taking radiographs

Mailed to the monitoring company once a month for evaluation

ALARA

as lows as reasonably achievable

Every possible method of reducing exposure to radiation should be employed

patient education

Explain the precautions taken for radiographs by talking about the prodcedure or providing a pamphlet

intraoral radiographic examination

A radiographic inspection of teeth and intraoral adjacent structures

Requires the use of intraoral image receptors

periapical, interproximal, and occlusal

3 Types of Intraoral Radiographic Examinations

periapical examination

Purpose: examine the entire tooth and 2mm of supporting bone

Technique: Paralleling and bisecting

Type of imaging receptor is in the name

interproximal examination

Purpose: examine the crowns of both the maxillary and mandibular teeth on a single film

Used for examining interproximal surfaces

bite-wing

What is the type of imaging receptor and technique used during interproximal examination

occlusal examination

Purpose: A larger film used to examine large areas of the maxilla or the mandible on one film

Film receptor type and technique is in the name

maximum permissible dose

Limit of ionizing radiation dose that a person is allowed to receive without incurring significant harmful side effects

50 mSv/year

What is the MPD of occupationally exposed people/radiographers

0.5 mSv/month

What is the MPD of pregnant dental personel during pregnancy months

1 mSv/year

What is the MPD of nonoccupationally exposed people

cumulative occupational dose

The accumulated lifetime radiation dose occupationally exposed workers must not receive

Calculation: worker’s age x 10 mSv

occlude

To close or to bite down

FMX

A series of intraoral dental images that show all the tooth-bearing areas of both jaws

Usually 14-20 images

tooth-bearing areas

The regions of the maxilla and mandible where the 32 teeth of the human dentition is normally located

dentulous

Areas of that exhibit teeth

edentulous

Areas where teeth are no longer present

FMX

Combination of periapical images and bite-wing images

diagnostic

Image that meets all the specific criteria for each intraoral image exposure

extraoral imaging examination

An inspection used to examine large areas of the skull or jaws

3

In order to take radiographs of a patient, How many years must have passed from their last FMX

0.25 mm

What is the minimum lead thickness needed for a lead apron to be effective

8in and 16in

What are the 2 sizes PID’s come in

round and rectangular

What are the two shapes PID’s come in