ORTHO cephalometrics

Question 1

in ortho when do we take radiographs?

Answer 1

confirm unerupted teeth
locate unerupted teeth
pathology
root morphology
assess skeletal pattern
monitor treatment changes

Question 2

what is cephalometrics?

Answer 2

the analysis and interpretation of standardised radiographs of the facial bones

Question 3

when is cephalometric analysis used?

Answer 3

skeletal discrepancies
incisor relationships

functional appliances
incisor change

research (with ethical approval)

Question 4

name the parts of a cephalostat?

Answer 4

scale
ear rods
nose piece
film
aluminium wedge

Question 5

where does the scale sit when using the cephalostat?

Answer 5

mid-sagittal plane

Question 6

what position should pt be in when using cephalostat?

Answer 6

frankfort plane horizontal to the floor
teeth in RCP

Question 7

What outlines are drawn in hand drawn cephalometrics?

Answer 7

soft tissue profile
cranial base
nasal bones
maxilla and teeth
mandible and teeth

trace an average of both eyes

Question 8

what are the landmarks on a ceph?

Answer 8

sella
nasion
ANS/ PNS
A point + B point
gonion
menton

Question 9

where is the nasion (N)?

Answer 9

the most anterior point of the fronto-nasal suture in the median plane

Question 10

where is the sella (S)?

Answer 10

the point representing the midpoint of the pituitary fossa (sella turcica)

Question 11

where is point A on a ceph? and what does it represent?

Answer 11

point at the deepest midline concavity of the anterior maxilla
represents the anterior limit of the maxilla

Question 12

can point A change in a person?

Answer 12

yes - with growth and tooth movement
because it is on alveolar bone

Question 13

where is the anterior nasal spine (ANS)?

Answer 13

the tip of the bony anterior nasal spine in the medial plane

Question 14

where is the posterior nasal spine (PNS)?

Answer 14

tip of the posterior nasal spine

Question 15

what can obscure the posterior nasal spine (PNS)?

Answer 15

developing upper 8s

Question 16

where is point B?

Answer 16

deepest concavity on the mandibular symphysis

Question 17

can point B change?

Answer 17

yes - with growth and tooth movement
because it is on alveolar bone

Question 18

where is the pogonion (pog)?

Answer 18

the most anterior point of the mandibular symphysis

Question 19

where is the menton (Me)?

Answer 19

the most inferior point on the mandibular symphysis

Question 20

where is the gonion (Go)?

Answer 20

the constructed point of intersection of the tangents of the ramus plane and the mandibular plane
the most posterior and inferior point on the angle of the mandible

Question 21

what dots make the cranial base?

Answer 21

S-N

Question 22

what dots make the maxilla?

Answer 22

ANS - PNS

Question 23

what dots make the mandible?

Answer 23

Go-Me

Question 24

what are the lines on a ceph?

Answer 24

S-N (cranial base)
N-A + N-B
ANS - PNS (maxilla)
Go- Me (mandible)
upper incisor
lower incisor

Question 25

what does the SNA angle indicate?

Answer 25

the relative antero-posterior positioning of maxilla in relation to cranial base

Question 26

what does an increased SNA angle indicate? and what angle would this be?

Answer 26

prognathic maxilla (forward) >82 degrees

Question 27

what does a decreased SNA angle indicate? and what angle would this be?

Answer 27

retrognathic maxilla (backwards) <82 degrees

Question 28

what does the SNB angle indicate?

Answer 28

antero-posterior positioning of the mandible in relation to cranial base

Question 29

what does an increased SNB angle indicate? and what angle would this be?

Answer 29

prognathic mandible >80 degrees

Question 30

what does a decreased SNB angle indicate? and what angle would this be?

Answer 30

retrognathic mandible <80 degrees

Question 31

what does the ANB angle denote?

Answer 31

the relative position of the maxilla and mandible to each other

Question 32

what does an increased ANB angle indicate? and what angle would this be?

Answer 32

class II skeletal pattern > 4 degrees

Question 33

what does a decreased or negative ANB angle indicate?

Answer 33

class III skeletal pattern

Question 34

what forms the MMPA (maxillo mandibular plane angle)?

Answer 34

intersection of mandibular plane with maxillary plane

Question 35

what does an increased MMPA angle indicate?

Answer 35

vertical growth pattern

Question 36

what does a reduced MMPA plane angle indicate?

Answer 36

horizontal growth pattern

Question 37

what does an increased incisor inclination angle indicate?

Answer 37

proclined incisors

Question 38

what does a decreased incisor inclination indicate?

Answer 38

retroclined incisors

Question 39

what is the E plane?

Answer 39

Ricketts esthetic plane line joins soft tissue chin and nose tip

Question 40

what are E plane measurements in a balanced face?

Answer 40

lower lip = 1-2mm upper lip = 2-3mm

Question 41

what type of digital software is available for digital cephalometric tracing?

Answer 41

dolphin imaging software OPAL image viewer PACS - graphic tools