Random Study Stuff

Question 1

(Alveolar bone defects in orthodontic patients)
What percentages of patients had bony dehiscences and fenestrations?

Answer 1

Bony dehiscences and fenestrations in 51% and 37% of patients respectively

Question 2

(Panoramic “dark band” sign)
In cases with a dark band across the roots on panoramic radiographs, what did CT reveal and how often?

Answer 2

In 63% of the cases where a dark band across the roots was observed on panoramic radiographs, CT revealed grooving of the root.

Question 3

(Impacted lower third molars: contact relationships)
What were the rates of contact with the mandibular canal and with the lingual cortex?

Answer 3

The tooth was in contact with the mandibular canal in 94% and with the lingual cortex in 86%

Question 4

(CT evaluation of impacted lower third molars)
What proportions were buccal, lingual, inferior, and inter-radicular for the mandibular canal course?

Answer 4

In 31% of the CT images, the course of the mandibular canal was buccal, in 33% lingual, in 26% inferior, and in 10% inter-radicular.

Question 5

What’ sthe difference between sensitivity and specificity?

Answer 5

Question 6

(Root fracture detection: CBCT vs dental radiography)
What were the sensitivity and specificity for dental radiography and for CBCT?

Answer 6

Sensitivity and specificity of root fractures were 26.3% and 100%, respectively, for dental radiography and 89.5% and 97.5%, respectively, for CBCT

Question 7

(Vertical root fracture detection with CBCT)
What were the sensitivity and specificity in suspected cases (n=32) confirmed by surgical exploration?

Answer 7

The sensitivity was 88%, and specificity was 75%.

Question 8

(Periapical pathology detection in posterior maxillary teeth)
In teeth referred for apical surgery, how did CBCT compare to PA’s for detecting lesions?

Answer 8

In 156 roots, CBCT showed significantly more lesions (34%, p < 0.001) than PA’s

Question 9

(CBCT exposure conclusions)
How does CBCT x-ray exposure compare with dental films?

Answer 9

X-ray exposure from CBCT imaging is in the same range as dental films

Question 10

(Dose reduction summary)
What reductions in effective dose are reported when changing parameters?

Answer 10

mA, kVp, FOV and collar reduce Effective Dose (E)
Thyroid collar alone reduces 51 - 57%!
12” –→ 9” FOV reduces by 24%
15mA –→ 2mA reduces by 86%
120 kVp –→ 60 kVp reduces by 90%

Question 11

(Background radiation)
What daily natural exposure value is cited? vs what effective dose range is listed for CBCT?

Answer 11

The average daily exposure from natural exposure is ~8 µSv

CBCT = 5.8 - 206 µS

Question 12

(X-ray radiation)
What type of damage do X-rays cause and what is noted about long-term effects?

Answer 12

Lacking a particle, X-rays cause the same type of damage as gamma radiation, but, like gamma radiation, cannot sit dormant and cause cancer in the long term

Question 13

(Gamma radiation)
What immediate effects can high-dose gamma radiation cause?

Answer 13

But the “damage in the immediate” is often far worse than the long-term damage alpha and beta cause; because it is difficult to stop, gamma radiation can go through the entire body of a person, and in a high dose it can kill them horribly in a short period of time.

Question 14

(Gamma radiation)
What distinguishes gamma radiation from alpha and beta radiation?

Answer 14

Unlike alpha and beta radiation, gamma radiation has no particle and is entirely an energy discharge from the unstable atom.

Question 15

(Beta radiation)
What hazards are associated with beta-emitting material?

Answer 15

Like alpha emitting material, beta emitting material can be inhaled or ingested, remaining for years and causing sickness. That is why it is important to wear a gas mask when traveling in a radioactive area.

Question 16

Like alpha emitting material, beta emitting material can be inhaled or ingested, remaining for years and causing sickness. That is why it is important to wear a gas mask when traveling in a radioactive area.

Answer 16

However, alpha emitting material can be inhaled or swallowed, and could potentially “stick” in the body and stay there for years, bombarding one area with alpha radiation. This usually causes deadly cancer to form.

Question 17

(Alpha radiation)
How is alpha radiation characterized in terms of overall harm compared to other types?

Answer 17

Out of all four types, alpha radiation is (for the most part) the least harmful.

Question 18

(Qualifying factor)
What is the QF for X-rays?

Answer 18

X-rays are the standard with a QF of 1

Question 19

(Qualifying factor)
How does the QF number relate to tissue damage?

Answer 19

Higher the number = greater tissue damage