Cephalometrics

Question 1

Why are Lateral Cephalograms taken in Orthodontics

Answer 1

A high percentage of severe malocclusions is associated with discrepancies in jaw relationships

Question 2

What are the TWO types of Skeletal Problems?

Answer 2

Vertical skeletal discrepancy attributed to an increased vertical growth pattern

Antero-posterior skeletal discrepancy attributed to a retrusive mandible

Question 3

When is a cephalogram indicated?

Answer 3

Marked antero-posterior discrepancy e.g. Class II and III malocclusions

Class I bimaxillary protrusion

Marked vertical discrepancy e.g. AOB, deep overbites

Question 4

What are the cranial base landmarks?

Answer 4

Sella
Nasion
Basion
Orbitale
Porion

Question 5

Definition of Sella

Answer 5

The geometric centre of the sella turcica

Question 6

Definition of Nasion

Answer 6

The most anterior portion of the frontal-nasal suture

Question 7

Definition of Basion

Answer 7

The most inferior tip of the clivus

The most anterior part of the foramen magnum

Question 8

Definition of Porion

Answer 8

The most superior point on the external auditory meatus

Question 9

Definition of Orbitale

Answer 9

The most inferior point of lateral orbital margin

Question 10

What is the Maxillary Outline?

Answer 10

Maxillary base and pterygo-maxillary fissure

Question 11

What are the Maxillary Landmarks?

Answer 11

1. Anterior nasal spine
2. Posterior nasal spine
3. A point (Subspinale)
4. Is point (Incisor superius)

Question 12

Definition of ANS

Answer 12

The most prominent point on the anterior maxilla in the mid-sagittal plane

Question 12

Definition of A point

Answer 12

The deepest point in the concavity of anterior maxilla in the mid-sagittal plane

Question 13

Definition of PNS

Answer 13

The distal most point on the hard palate in the mid-sagittal plane

Junction between hard and soft palate

Question 14

What are the Mandibular Outlines?

Answer 14

Ramus

Condyle

Mandibular body

Symphysis

Question 15

What are the Mandibular Landmarks?

Answer 15

Pogonion

Menton

Gonion

Point B (Supramentale)

Ii point (Incisor inferius)

Question 16

Definition of Pogonion

Answer 16

The most anterior point on the mandibular symphysis

Question 17

Definition of Menton

Answer 17

The most inferior point on the mandibular symphysis in the midline

Question 18

Definition of B point

Answer 18

The point of the deepest concavity anteriorly on the mandibular symphysis

Question 19

Definition of Gonion point

Answer 19

The most posterior, inferior point on the mandibular angle

Question 20

A HYPOdivergent facial pattern means that the planes meet?

Answer 20

Very far behind skull

Question 21

A HYPERdivergent facial pattern means that the planes meet?

Answer 21

Near or within skull

Question 22

What does SNA measure?

Answer 22

The angle that measures the relationship of maxilla to cranial base

Patient’s SNA is ___ which is ___ , indicating that the patient has a protrusive, retrusive or maxilla in ideal AP position with reference to the cranial base

Question 23

What does SNB measure?

Answer 23

The angle that measures the relationship of the mandible to cranial base

Patient’s SNB is ___ which is ___ , indicating that the patient has a prognathic, retrognathic or mandible in ideal AP position with reference to the cranial base

Question 24

What does ANB measure?

Answer 24

The angle measures the relative position of maxilla to mandible

Patient’s ANB is ___ which is ___ , indicating that the patient has a Class I/Class II/Class III in ideal AP position with reference to the N point

Question 25

What does WITS value mean?

Answer 25

Patient’s WITS is ___ which is ___ , indicating that the patient has a Class I/Class II/Class III in ideal AP position with reference to the FOP.

A point should be posterior B point (Class 1 = Negative value)

Question 26

What does Frankfort-Mandibular plane angle mean?

Answer 26

Patient’s FMA is ___ which is ___ , indicating that the patient’s mandible is hyper/hypo/normodivergent with reference to the Frankfort plane.

This confirms/refutes the conclusion from the MMA value.

Question 27

What does Maxillary-Mandibular plane angle mean?

Answer 27

Patient’s MMA is ___ which is ___ , indicating that the patient’s mandible is hyper/hypo/normodivergent with reference to the maxillary plane.

Question 28

What does LAFH value mean?

Answer 28

Patient’s LAFH is ___ which is ___ , indicating that the patient has an increased/decreased/normal LAFH relative to TAFH

Question 29

What does U1-Mx mean?

Answer 29

Patient’s U1-Mx is ___ which is ___ , indicating that the patient’s maxillary incisors are proclined/retroclined/ideally inclined with reference to the maxillary plane

Question 30

What does L1-Apog mean?

Answer 30

Patient’s L1-Apog is ___ which is ___ , indicating that the incisal edges of the patient’s lower incisors are protrusive/retrusive/in ideal AP position with reference to A-pog line

Question 31

What does L1-MP mean?

Answer 31

Patient’s L1-MP is ___ which is ___ , indicating that the patient’s lower incisors are protrusive/retrusive/in ideal AP position with reference to mandible plane

Question 32

What does Patient’s Lower lip to E line value mean?

Answer 32

Patient’s Lower lip to E line is ___ which is ___ , indicating that the patient’s lower lip is protrusive/retrusive/in ideal AP position with reference to E line