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Flashcards in Transition Zones Deck (27)
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1
Q

What is/are the characteristic(s) of occipitalization of occiput?

A

the atlas may be partially or completely fused to the occiput

2
Q

What is another way of implying occipitalization of C1?

A

atlas assimilation

3
Q

What is the incidence of occipitalization of C1?

A

0.1% to 0.8%

4
Q

When do the centers of ossification for the odontoid process first appear?

A

during the last trimester in utero

5
Q

When do the bilateral ossification centers for the odontoid process fuse?

A

at or shortly after birth

6
Q

What joint is formed between the odontoid process ossification centers and the centrum of C2?

A

subdental synchondrosis

7
Q

Ossification between the odontoid process and centrum joint of C2 first appears at what age?

A

4 years old

8
Q

A joint between the odontoid process and centrum of C2 is last identified at what age?

A

7 years old

9
Q

What is the name given to the condition in which the joint formed between the odontoid process and centrum of C2 persists beyond age 7?

A

os odontoideum

10
Q

What is the name given to the joint between the odontoid process and centrum of C2 which is still evident beyond age 7?

A

persistent subdental synchondrosis

11
Q

What is the name given to the joint formed between the tip of the dens and the odontoid process centers of ossification?

A

tip of the dens synchondrosis

12
Q

At what age will the tip of the dens center of ossification appear?

A

sometime in early adolescence

13
Q

At what age will the tip of the dens fuse with the odontoid process?

A

before age 12

14
Q

If the joint formed between the tip of the dens and odontoid process centers of ossification persists beyond age 12, what is the condition called?

A

terminal ossicle

15
Q

What is a basilar impression?

A

persistence of the nonunion of the basilar and condylar parts of the chondrocranium such that the cartilage deforms due to the weight of the brain

16
Q

What is the basilar invagination?

A

the upper cervical spine appears to be invaginated into the skull on x-ray analysis

17
Q

What is the incidence of rib-related changes following dorsalization of C7?

A

from one-half to two and one-half percent of the population

18
Q

Do patients typically present with symptoms specific for dorsalization of C7?

A

no, they are typically asymptomatic

19
Q

What is the gender bias suggested in dorsalization of C7?

A

female

20
Q

What alterations in C7 facet orientation may accompany dorsalization?

A

the superior articular facet of C7 may change from back, upward, and medial to that of a typical thoracic facet… back, upward, and lateral; the inferior articular facet is unchanged

21
Q

What percent of the population may demonstrate thoracic-like features at C7?

A

up to 46%

22
Q

What T1 facet orientation changes may accompany cervicalization?

A

the superior articular facet may change from back, upward, and lateral to back, upward, and medial; the inferior articular facet is unchanged

23
Q

What is the incidence of cervicalization of T1 in the population?

A

up to 28% of the population

24
Q

What is the incidence of lumbar ribs in the population?

A

over 7% of the population demonstrates lumbar ribs

25
Q

What L1 facet orientation changes may accompany dorsalization?

A

the superior articular facet may change from concave, back, upward, and medial to flat, back, upward, and lateral; the inferior articular facet is unchanged

26
Q

What is the gender bias associated with dorsalization of L1?

A

males are two to three times more affected

27
Q

What T12 facet orientation changes may accompany lumbarization?

A

the superior articular facet may change from flat, back, upward, and lateral to concave, back, upward, and medial; the inferior articular facet is unchanged