10/4

Question 1

What kind of radiation effect results in acute radiation syndrome

Answer 1

Somatic radiation effects (deterministic, short-term)

Question 2

What are the dosages of a SUB-lethal exposure
LETHAL exposure
SUPRA-lethal exposure

Answer 2

SUB = < 2 Gy
LETHAL = 2-8 Gys
SUPRA = > 8

Question 3

What are the phases of Acute Radiation Syndrome?

Answer 3

1. Prodromal period (sickness, fatigue: several weeks)
   SUB
2. Hematopoietic Syndrome (irreversible: spleen and bone marrow loss of blood cells: death within 10-30 days)
   LETHAL (2-10)
3. GI Syndrome (intestinal atrophy and ulceration, infection: death within 3-5 days)
   SUPRA (10-100)
4. CNS and Cardiovascular Syndrome (Brain damage: dead in 48 hours
   SUPRA (>100)

Question 4

What is the radiation therapy for intraoral cancer?

Answer 4

50 Gy

Question 5

What are the radiation effects to the following parts of the oral cavity?
Mucosa
Taste Buds
Salivary Glands
Teeth
Bone
Muscle

Answer 5

Mucosa: mucositis (secondary infections)
Taste Buds: loss of taste
Salivary Glands: xerostomia (pH becomes acidic and can decalcify enamel)
Teeth: Poor development + radiation caries (mainly in children)
Bone: Osteoradionecrosis
Muscle: FIbrosis

Question 6

What is the MPD for occupational limit? Non-occupational limit?

Answer 6

5 rem/year = 50 msV
0.5 rem/year = 5 msV

Question 7

What is the average annual effective dose of ionizing radiation in the late 1900s

Answer 7

3.6 (0.39 from X-ray, 0.14 from nuclear medicine = 1/6 of radiation exposure)

Question 8

What two cancers have the highest risk from dental radiographic exposure?

Answer 8

LEUKEMIA and THYROID cancer