2. Cephalometrics

Question 1

How far is the ceph X-ray bean from the patient’s head

Answer 1

5 feet

Question 2

How is the head adjusted to take a ceph

Answer 2

according to the frankfort horizontal plane (pointer aligns with orbitale)

Question 3

Describe the sella turcica

Answer 3

center of pituitary fossa of the sphenoid

Question 4

Describe the nasion

Answer 4

most anterior point of the frontonasal suture

Question 5

Describe the orbitale

Answer 5

lowest point in the inferior margin of orbit

Question 6

Describe the anterior nasal spine

Answer 6

tip of the bony anterior nasal spine

Question 7

Describe the posterior nasal spine

Answer 7

tip of posterior spine of the palatine bone in the hard palate

Question 8

Describe the pterygomaxillary fissure

Answer 8

anterior wall represents retromolar tuberosity of maxilla and posterior wall represents the pterygoid process of sphenoid bone

Question 9

Describe the point A (subspinale)

Answer 9

deepest midline point in the maxilla between anterior nasal spine and prosthion (supradentale)

Question 10

Describe the point B (supramentale

Answer 10

deepest midline concavity on the mandibular symphysis between infradentale and pogonion

Question 11

Describe the gonion

Answer 11

Most inferior posterior point on the jaw angle

Question 12

Describe the gnathion

Answer 12

point midway between the most inferior and anterior points of the bony chin

Question 13

Describe the menton

Answer 13

most inferior midline point on the mandibular symphysis

Question 14

Describe the pogonion

Answer 14

most anterior point on the chin

Question 15

Describe the porior

Answer 15

midpoint on upper edge of the external auditory meatus

Question 16

Describe the basion

Answer 16

lower most point on the anterior margin of the foramen magnum in the mid-sagittal plane

Question 17

If the SNA is < _ degrees the (maxilla/mandible) is (Protrusive/retrusive)

Answer 17

82…maxilla…retrusive (class III)

Question 18

If the SNA is > _ degrees the (maxilla/mandible) is (Protrusive/retrusive)

Answer 18

82…maxilla…protrusive (class II)

Question 19

If the SNB is > _ degrees the (maxilla/mandible) is (Protrusive/retrusive)

Answer 19

80… mandible… protrusive (class III)

Question 20

If the SNA is < _ degrees the (maxilla/mandible) is (Protrusive/retrusive)

Answer 20

80… mandible… retrusive (class II)

Question 21

If the ANB is > _ degrees the skeletal relationship is Angle’s class (I/II/III)

Answer 21

2… class II

Question 22

If the ANB is < _ degrees the skeletal relationship is Angle’s class (I/II/III)

Answer 22

2… class III

Question 23

What does it mean when the interincisal angle is

Answer 23

130… incisors are flaired

Question 24

What does it mean when the interincisal angle is >_degrees

Answer 24

130… incisors are retrusive

Question 25

What does 1 to NA signify and what are the standard numbers

Answer 25

upper central incisor angulation…. 22 degrees… upper central is 4 mm in front of NA

Question 26

What does 1 to NB signifiy and what are the standard numbers

Answer 26

lower central incisor angulation to nasion-point B

-20 degrees and most porminent part of lower central is 4 mm in front of NB

Question 27

Growth axis plane is from what two pointment

Answer 27

Sella and gnathion

Question 28

Growth plane less thant 59 indicates

Answer 28

more horizontal growth of the mandible

Question 29

Palatal plane is measured from what two points

Answer 29

ANS and PNS

Question 30

Mandibular plane is measured from

Answer 30

gonion to gnathion

Question 31

High mandibular angle indicates? Low mandibular angle indicates?

Answer 31

High angle= open bite tendency

Low angle= deep bite tendency

Question 32

Facial plane is measured from what two points?

Answer 32

Nasion and porion

Question 33

Frankfort plane is measured from

Answer 33

porion and orbitale