Ceph Skeletal Dental Measurements

Question 1

Upper Incisor to Sella Nasion Plane

Answer 1

Lines: U1 Long Axis, SN

Measure: Posterior inferior angle

Indicates: angulation of upper incisor (proclined or retroclined)

Norm = 104 +/- 6 degrees

Question 2

Upper Incisor to A Point Perpendicular

Answer 2

Lines = Frankfort Horizontal; A Point Perpendicular

Measure (mm) = facial U1 to A1 Perp

Indicates = AP position of upper incisor (protruded/retruded)

Norm = 5 +/- 1 mm

Question 3

Lower Incisor to A-Pogonion Plane

Answer 3

Lines = APo

Measure (mm) = to labial surface of L1; perpendicular to APo

Indicates = AP position of lower incisor (protruded/retruded)

Norm = 1 +/- 2.5 mm

Question 4

Lower Incisor to A-Pogonion Plane (#2?)

[according to my notes - not on the test]

Answer 4

Constructed L1-APo

Used for surgical or functional appliance treatment planning

Can use template or construction method

Incisor measurement changes with jaw position

Question 5

Upper Incisor to Lower Incisor

Answer 5

Lines = Long axis or upper and lower incisors

Measure = inner angle btwn incisors’ long axis

Indicates = relationship of incisors

Norm = 131 +/- 9 degrees

[Important because directly related to esthetics]

Question 6

Lower Incisor to Mandibular Plane

Answer 6

Lines = Long axis of lower incisor; mandibular plane

Measure = inner angle

Indicates = lower incisor inclination (proclined/retroclined)

Norm = 93 +/- 7 degrees

Question 7

Upper Incisor to Upper Lip

Answer 7

Lines = Stomion and Incisor Tip

Measure (mm) = Inferior part of upper lip; tip of maxillary incisor

Indicates = incisor’s vertical position (deficient/excess)

Norm = 2 +/- 1 mm

Question 8

Upper Incisor to Nasion-A Point Plane

Answer 8

Lines = NA, Long axis upper incisor

Measure = Inner/upper angle

Indicates = upper incisor inclination (proclined/retroclined)

Norm = 22 +/- 4 degrees

Question 9

Upper Incisor to Nasion-A Point Plane (#2?)

Answer 9

Lines = NA

Measure (mm) = Tip of incisor to NA line; right angle to NA line

Indicates = incisor’s AP position (protruded/retruded)

Norm = 4 +/- 1mm

Question 10

Lower Incisor to Nasion-B Point Plane

Answer 10

Lines = NB, Long axis of lower incisor

Measure = inner/lower angle

Indicates = Incisor inclination (proclined/retroclined)

Norm = 25 +/- 4 degrees

Question 11

Lower Incisor to Nasion-B Point Plane (#2)

Answer 11

Lines = NB

Measure (mm) = incisal tip to NB line; at right angles

Indicates = incisor’s AP position (protruded/retruded)

Norm 4 +/- 1 mm

Question 12

Overbite

Answer 12

Measure = vertical incisal edge difference

(most prominent incisors)

Norm = 2 +/- 2 mm

Question 13

Overjet

Answer 13

Measure = horizontal incisal edge difference

(most prominent incisors)

Norm = 2 +/- 2 mm