lateral cephalometrics

Question 1

Why is cephalometrics used in diagnosis and treatment planning?

Answer 1

1. Allows assessment of AP and vertical skeletal patterns.
2. Shows the incisor positions and angular ion.
3. Monitors the progress of treatment.

Question 2

What are the 10 cephalometric points?

(SNABO and Po ANS PNS Go Me)

Answer 2

S - sella
N - naison
A - A point
B - B point
O - orbitale
Po - porion
ANS - anterior nasal spine
PNS - posterior nasal spine
Go - gonion
Me - menton

Question 3

Where is the sella cephalometric point?

Answer 3

The midpoint of sella turcica (depression in the sphenoid bone containing the pituitary gland).

Question 4

Where is the Naison cephalometric point located?

Answer 4

In the most anterior point on the frontonasal suture.

Question 5

What is the A point in cephalometrics?

Answer 5

The point of deepest concavity anteriorly on the maxillary alveolus.

Question 6

Where is B point in cephalometrics?

Answer 6

The point of deepest concavity anteriorly on the mandibular symphysis.

Question 7

Where is Orbitale located?

Answer 7

The most inferior, anterior point located on the infraorbital rim.

Question 8

Where is the porion located?

Answer 8

The uppermost outermost point on the bony external auditory meatus.

Question 9

Where is the ANS?

Answer 9

The tip of the posterior nasal spine.

Question 10

Where is the PNS?

Answer 10

The tip of the posterior nasal spine.

Question 11

Where is Gonion?

Answer 11

The most posterior inferior point on the angle of the symphysis.

Question 12

Where is menton?

Answer 12

The most inferior point on the mandibular symphysis.

Question 13

Which 2 points are connected by the SN line?

Answer 13

Midpoint of sella turcica and naison.

Is taken to resemble the cranial base.

Question 14

Where is the Frankfort Plane?

Answer 14

The line joining porion and orbitale.

(runs from the tragus to the bottom of the orbit)

Question 15

Which 2 points are joined by the mandibular plane?

Answer 15

Gonion and Menton

Question 16

Which 2 points are joined by the Maxillary Plane?

Answer 16

The ANS and PNS

Question 17

What is the Functional Occlusal Plane?

Answer 17

The line drawn between cusp tips of permanent molars and premolars.

Question 18

What does the SNA represent?

Answer 18

The relative A-P position of the maxilla to the cranial base.

Question 19

What does the SNB angle represent?

Answer 19

The relative A-P position of the mandible to the cranial base.

Question 20

What does the ANB angle represent?

Answer 20

The relative A-P position of the maxilla to the mandible.

Question 21

What can the ANB angle be used to determine?

Answer 21

Skeletal Class

Question 22

If the ANB angle is 2-4º, which skeletal class would this correspond to?

Answer 22

Class I

Question 23

If the ANB angle is greater than 4º, which skeletal class would this correspond to?

Answer 23

Class II

Question 24

If the ANB angle is less than 2º, which skeletal class would this correspond to?

Answer 24

Class III

Question 25

Which 2 angles can a variation in position N affect?

Answer 25

SNA and SNB

Question 26

What assumption does the Eastman Analysis make?

Answer 26

That the cranial base (SN) is a reliable basis for comparison.

Question 27

Describe the Upper Incisors to Maxillary Plane Angle

Answer 27

The angle between the maxillary plane and axis of maxillary incisors.

Question 28

Describe the Lower Incisor to Mandibular Plane Angle.

Answer 28

The angle between the mandibular plane and mandibular incisors.

Question 29

What are both the UI/Max and LI/Mand angles used to determine?

Answer 29

Incisal position and if they are average inclination, proclined or retroclined.

Question 30

What is Wits Analysis?

Answer 30

Compares the maxilla and mandible with the functional occlusal plane.

Question 31

What is the functional occlusal plane?

Answer 31

The line drawn between the cusp tips of molars and premolars.