2. The Steiner analysis, developed and promoted by
Cecil Steiner in the 1950s, can be considered the first
of the modern cephalometric analyses for two reasons:
1. It displayed measurements in a way that emphasized
not just the individual measurements but their
interrelationship into a pattern.
2. It offered specific guides for use of cephalometric
measurements in treatment planning. Elements of it
remain useful today.
3. The Steiner numerical analysis, also suggests a series
of measurements not only to diagnose the problem
but it also provides guidelines for treatment planning
based on the prediction of changes that take place as a
result of growth and/or orthodontic therapy.
4. REFRENCE PLANE
Steiner use SELLA to NASION(anterior cranial base)
line as a reference plane for his analysis
ADVANTAGE
According to Steiner S-N plane is a best reference
plane because
“If head deviate from true profile position these
two mid line points are minimally moved, even if the
head rotates in a cephalostat”
7. SKELETAL ANALYSIS
Relate upper and lower jaw with skull and each other
in antero posterior axis
It consist of
5 Angular measurements
8. SNA ANGLE(82±2)
A commonly used measurement (of the R. A. Riedel
analysis) introduced by Steiner for assessment of the
anteroposterior position of the maxilla with regards to
the cranial base.
The inferior posterior angle formed by the
intersection of lines SN and NA is measured.
11. SNB angle(80±2)
A measurement introduced by Steiner to evaluate the
anteroposterior position of the mandible in relation to
the cranial base (also part of the R. A. Riedel analysis).
The inferior posterior angle formed by the intersection
of lines NA and NB is measured.
14. Angle ANB (3 ± 1)
The difference between SNA and SNB-the ANB angle-
indicates the magnitude of the skeletal jaw
discrepancy.
This to Steiner was the measurement of real interest.
15. The magnitude of the ANB angle, however, is
influenced by two factors other than the
anteroposterior difference in jaw position.
1. The vertical height of the face: As the vertical
distance between nasion and points A and B
increases, the ANB angle will decreases.
2. If the antero- posterior position of nasion is
abnormal, the size of the angle will be affected.
16. As SNA and SNB become larger and the jaws are more
protrusive, even if their horizontal relationship is
unchanged, it will be registered as a larger ANB angle.
Because of this criticism different indicators of jaw
discrepancy are now a days used.
17. Mandibular plane angle(32±4)
A measurement introduced by C. C. Steiner for
assessment of the steepness of the mandibular plane
in relation to the cranial base.
The anterior angle formed by the intersection of SN
and GoGn is measured.
W. B. Downs defined the mandibular plane angle as
the anterior angle formed by the intersection of the
Frankfort horizontal plane and a tangent to the lower
border of the mandible and symphysis.
18.
19. SN-OCCLUSAL PLANE ANGLE(17±4)
According to Steiner occlusal plane is
“Region of overlapping cusps of first premolar and
molar”
Determine the relation of teeth in occlusion with
cranial base
i. Increased in angle shows HIGH ANGLE
CASE(SEKELETAL OPEN BITE)
ii. Decreased in angle shows LOW ANGLE
CASE(SKELETAL DEEP BITE)
20. DENTAL ANALYSIS
Relates upper and lower incisors with each other and
with their respective jaws
3 Angular measurements
2 Linear measurements
1 Ratio
21. UI-NA angle(22)
Angle formed between the long axis of upper incisors
and line drawn from nasion to pogonoin
Describe axial inclination of upper incisors
Determine relative angular relationship of upper
incisor teeth
o Increased: Greater angulation of upper incisor
o Decreased: Lesser angulation of upper incisor
22. UI-NA DISTANCE(4mm)
Determine A-P position of upper incisor with relation
to N-A line
Distance measured from most anteriorly placed point
on labial side of crown of upper incisor to N-A line
Increased: Forwardly placed upper incisor
Decreased: backwardly placed upper incisor
23. LI-NB angle(25)
Angle formed between the long axis of lower incisors
and line drawn from nasion to pogonoin
Describe axial inclination of lower incisors
Determine relative angular relationship of lower
incisor teeth
Increased: Greater angulation of lower incisor
Decreased: Lesser angulation of lower incisor
24. LI-NB DISTANCE(4mm)
Determine A-P position of lower incisor with relation
to N-A line
Distance measured from most anteriorly placed point
on labial side of crown of lower incisor to N-A line
Increased: Forwardly placed lower incisor
Decreased: backwardly placed lower incisor
25. It is important to understand that it is possible for
both upper and lower incisors to have normal
angular(axial)relation with N-A line but have
disturbance in A-P positioning(forward or backward
placed incisors)
Reverse relationship of A-P positioning and axial
inclination or angular relation is also true.
26. INTERINCISAL ANGLE(135±5)
Angle between long axes of upper and lower incisors.
Average value: 135.4’ ( 130 to 150.5’)
increased in class I bimaxillary protrusion
28. Holdaway ratio (LI-NB/Pg-NB)
A measurement introduced by R. A. Holdaway to
evaluate the relative prominence of the mandibular
incisors, as compared to the size of the bony chin.
It is calculated as the ratio of the linear distance from
the labial surface of the mandibular central incisor to
the NB line, over the linear distance of the chin to the
same line.
29. If ratio is 2:1 it means that lower incisors are more
proclined as compared to chin prominence.
If discrepancy is 2mm=acceptable
3mm=less desirable
4mm=correction indicated
31. SOFT TISSUE ANALYSIS
To assess balance and harmony of lower facial profile
2 linear measurements
32. S-line (Esthetic plane of Steiner)
A line connecting the midpoint of the columella of the
nose to the soft tissue pogonion.
According to C. C. Steiner, the lips should fall on this
line and any deviation shows prominence or flatness of
the lips.
