Postero anterior cephalometry/certified fixed orthodontic courses by Indian dental academy

POSTEROANTERIO
R
CEPHALOMETRY

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


Introduction
 In

orthodontics , the primary indication for
obtaining a posteroanterior cephalometric
film is the presence of facial asymmetry, it is
also important in cases of dentoalveolar
asymmetries, dental and skeletal crossbites,
and functional mandibular displacements.
(transverse discrepancies)
 The posteroanterior cephalometric projection,
also called as the Caldwell projection.




1.
2.

3.

Importance of posteroanterior cephalometry
is in
Orthodontic surgery planning
Differential tooth eruption with segmental
TMJ therapy
Functional jaw orthopaedics including three
dimensional improvements in facial or
dental proportion or symmetry.

 Tracing

suggestion

1) One must ensure that the head position and
intermaxillary occlusal relationships that appear
in the X-ray do not differ significantly from those
identified during the clinical or photographic
evaluation of the patient or those found in the
analysis of dental cast.
2) Examine the cephalogram in order to exclude
the possibility of pathology of the hard and soft
tissues involved.
3) During tracing of the posteroanterior
cephalogram, it is essential to bear in mind
where the structures have been identified in
lateral cephalogram

.

4) Tracing of posteroanterior cephalogram may
begin with the midline structures seen in the
lateral cephalogram and should include the
occipital, parital, frontal, nasal bones, the
maxilla, the sphenoid bone, and the symphysis
of the mandible.
5) The fan of x-ray beam expands as it passes
through the head, causing a divergence
between the images of all bilateral structures
except those along the central beam.
Structures whose images are doubled and
exhibit an apparent asymmetry are
conventionally averaged and traced as a single
image.

Landmarks












LANDMARKS
ag- antegonion – the highest
point in the antegonial notch
ans- anterior nasal spine
cd- condylar- the most
superior point of the condylar
head
cor –coronoid – the most
superior point of the coronoid
process
iif- incision inferior frontale –
the midpoint between the
mandibular central incisiors at
the level of the incisal edges










isf- incision superior frontale –
the midpoint between the
maxillary central incisors at the
level of incisal edges.
lpa – latereal pyriform aperature
– the most lateral aspect of the
pyriform aperature.
lo – larero – orbitale – the
intersection of the lateral orbital
contour with the innominate
(oblique) line
m – mandibular midpoint –
located by projecting the mental
spine on the lower mandibular
border , perpendicular to the
line ag – ag.








lm- mandibular molar – the most
prominent lateral point on the
buccal side of the second
deciduous or first permanent
mandibular molar
ma – mastoid – the lowest point
of the mastoid process
mx – maxillare – the intersection
of the lateral contour of the
maxillary alveolar process and
the lower contour of the
maxillozygomatic process of the
maxilla
um – maxillary molar – the most
prominent lateral point on the
buccal surface of the second
deciduous or first maxillary
molar








mo- medio-orbitale – the
point on the medial orbital
margin that is closest to the
median plane
mf- mental foramen – the
center of the mental foramen
om- orbital midpoint – the
projection on the line lo-lo of
the top of the nasal septum at
the base of crista galli
za- point zygomatic arch –
point at the most lateral
border of the center of the
zygomatic arch








tns- top nasal septumthe highest point on the
superior aspect of the
nasal septum
mzmf- zygomaticofrontal
medial suture point-in
-point at the medial
margin of the
zygomaticofrontal suture
lzmf- zygomaticofrontal
lateral suture point-out –
point at the lateral margin
of the zygomaticofrontal
suture



1.

2.

3.
4.
5.

Most of the posteroanterior cephalometric analysis
described in the literature are quantitative , and
they evaluate the craniofacial skeleton by means
of linear absolute measurements of
Width or height ( Grummons and Kappeyne 1987,
Athanasiou et al 1992, Ricketts et al 1972, Solow
and Ingerslev 1975)
Angles (Grummons and Kappeyne 1987,
Athanasiou et al 1992, Ricketts et al 1972, Solow
and Ingerslev 1975)
Ratios (Costaras et al 1982, Grummons and
Kappeyne 1987, Athanasiou et al 1992)
Volumetric comparison (Grummons and
Kappeyne 1987)
Using qualitative methods (Graysons et al 1983)

 Landmarks

and variables that can be identified
on coronal planes of different depths in the
same posteroanterior cephalogram can provide
useful information concerning the vertical,
transverse, and saggital dimensions of the
craniofacial dimension.

 The

multiplane analysis developed by grayson
et al (1983) is the best and most complete
method in this category.

Method of Analysis
1.





Multiplane cephalometric analysis
(Grayson Analysis 1983)
Introduction
Landmarks are identified in different frontal planes at
selected depths of the craniofacial complex and
subsequent skeletal midlines are constructed in
saggital plane.
The midpoints and midlines may be combined and a
‘warped midsaggital plane’ can be the outcome of
the analysis.



Method



Analysis is performed on three different acetate
papers using the same posteroanterior
cephalogram.
Structures are traced within or near the three
different planes indicated on the lateral view.




Tracing of landmarks for various planes




In the first acetate sheet,
for plane A, orbital rims (A)
along with pyriform
aperature (B), maxillary
and mandibular incisors
(C), and the midpoint of
the symphysis (D) are
outlined.
This first tracing,
represents the anatomy of
the most superficial
aspect of the craniofacial
complex, as indicated by
plane A, is present





On the Second sheet, for
plane B, the greater and
lesser wings of sphenoid (A),
the most lateral cross-section
of the zygomatic arch (B), the
coronoid process (c), the
maxillary and mandibular first
permanent molars (D), the
body of the mandible (E), and
the mental foramina (F) are
traced.
These structures are located
on or near the deeper
coronal plane B.





Third tracing, for plane C,
includes the upper surface of
the petrous portion of the
temporal bone (A), the
mandibular condyles with the
outer border of the ramus
down to the gonial angle (B),
and the mastoid processes
(C) with the arch of temporal
and parietal bones
connecting them.
This tracing corresponds to
the plane C.

When these three tracings are viewed
separately, they reveal cross section of the
craniofacial complex.
 For each tracing , midsaggital midlines are
constructed as follows.












For plane A, it Passes through
orbits, Pyriform aperature, incisors
Mce- the centrum of each orbit is
identified and the midpoint Mce is
constructed,
Mp- the most lateral point on the
perimeter of each pyriform
aperature is located, and the
midpoint Mp is marked,
Mi- the midpoint Mi is constructed
between the maxillary and
mandibular incisors,
Mg- point Mg is identified at the
gnathion area







All these midpoints are close to the midline in some
sense. The midline in plane A can be constructed by
connecting these midpoints.
The result is a segmented construction of these
midlines , whose angles express the degree of
asymmetry of the structures in this specific plane.
The same principle are applied to the planes B and
C.











For plane B (for sphenoid and
zygomatic arch region) the
midpoint that are used are
point Msi, which is the bisector
between points Si, (point of
intersection of the shadow of
the greater and lesser wing of
sphenoid)
Point Mz, between the center
of the zygomatic arches,
Point Mc, between the tips of
the coronoid processes,
Point Mx, between left and
right maxillare,
Point Mf, between left and
right mental foramina.










For plane C , the midpoints used
are
Point Md – between heads of
condyles,
Point Mm – between the
innermost inferior points of the
mastoid processes,
Point Mgo – between the two
gonions.







If the three tracings are
superimposed , the phenomenon
of wraping within the craniofacial
skeleton can be observed.
The midline constructs deviate
progressively laterally as one
passes from plane C, through
plane B, to the plane A.
This multiple analysis gives the
possibility to view the saggital
plane in posteroanterior
cephalometry.

Grummons analysis





Introduction
The analysis is presented in two forms: the
comprehensive frontal asymmetry analysis and the
summary frontal asymmetry analysis.
The analysis consist of different components,
including horizontal planes, mandibular morphology,
volumetric comparison, maxillomandibular
comparison of asymmetry, linear asymmetry
assessment, maxillomandibular relation, and frontal
vertical proportions

•Landmarks used in Grummons
analysis
Ag -antegonial notch
ANS Anterior nasal spine
Cg crista galli
Cd condylion (most superior
aspect)
Fr foramen Rotundum
J jugal process
Me menton
MSR Mid-saggital reference line
at crista galli

•Landmarks used in Grummons
analysis

Nc nasal cavity at widest point
Z Zygomatic frontal suture,
medial aspect
ZA zygomatic arch
A1 upper incisor edge
B1 lower incisor edge


The practical procedure includes the
following
1.








.

Construction of four horizontal
planes
One connecting the medial
aspect of the zygomaticofrontal
suture (Z);
One connecting the centers of
the zygomatic arches (ZA); .
One connecting the medial
aspect of the jugal process (J)
and ;
One parallel to Z- plane through
menton.
These planes are drawn to show
the degree of parallelism and
symmetry of facial structures.

2. A midsaggital reference
line (MSR)
 Is constructed from crista
galli (Cg) through the
anterior nasal spine
(ANS) to the chin area .
 If anatomical variation in
upper and middle facial
region exist, an
alternative way of making
MSR is, draw a line from
midpoint of Z- plane
either through ANS or
midpoint of both foramina
rotundum (Fr - Fr line).

3. Mandibular morphology
analysis  Left sided and right
sided triangles are
formed between the
head of the condyle
(Co) to the antegonial
notch (Ag) and menton
(Me).
 A vertical line from ANS
to Me visualizes the
midsaggital plane in the
lower face.

4. Volumetric comparison –
 Four connected points
determine an area, and here a
connection is made between
the points;
 Condylion (Co);
 Antegonial notch (Ag);
 Menton (Me) and ;
 The intersection with a
perpendicular from Co to MSR.
 Two polygons (left and right)
are defined by these points can
be superimposed with the aid of
a computer program, and a
percentile value of symmetry
can be obtained.

5. Maxillomandibular
comparison of asymmetry –
 Four lines are constructed,
perpendicular to MSR, from
Ag and from J,
 And lines from Cg to Ag, are
also drawn.
 Two pairs of triangles are
formed in this way, and
each pair is bisected by
MSR.
 If symmetry is present , the
four triangles becomes two
triangles, namely J-Cg-J
and Ag-Cg-Ag.
 This assess symmetries in
both jaws.

6. Linear asymmetry
assessment;
 The linear distance to MSR
and the difference in the
vertical dimension of the
perpendicular projections of
bilateral landmarks to MSR
are calculated for the
landmarks Co, NC, j, Ag,
and Me.


7. Maxillomandibular relation –
 The distances from the buccal
cusps of the maxillary first molar
to the J - perpendiculars are
measured.
 Lines connecting Ag-Ag and
ANS-Me, and the MSR line, are
also drawn to reveal dental
compensations for any skeletal
asymmetry, the so-called
maxillomandibular imbalance in
horizontal or vertical planes.
 This shows midline asymmetry
of the upper and lower incisors
and asymmetry in occlusal
plane.

8. Frontal vertical proportion
analysis  Ratios of skeletal and dental
measurements, made along
the Cg-Me line, are
calculated with division at
ANS, A1 and B1.
(A1: upper central incisor
edge, B1: lower central
incisor edge):
 The following ratios are
taken into consideration
 Upper facial ratio - Cg-ANS :
Cg-Me;
 Lower facial ratio - ANSMe : Cg-Me;












Maxillary ratio - ANS-A1 :
ANS-Me;
Total maxillary ratio - ANSA1 : Cg-Me;
Mandibular ratio – B1-Me :
ANS-Me;
Total mandibular ratio – B1Me : Cg-Me;
Maxillomandibular ratio –
ANS-A1 : B1-Me.



These ratios can be compared with common
facial aesthetic ratios and measurements.


The summary facial asymmetry analysis
includes only the construction of the horizontal
planes, the mandibular morphology analysis,
and the maxillomandibular comparison of facial
asymmetry.
 This provides a practical summary of the
patient’s frontal asymmetry , emphasizing key
dentoalveolar and skeletal factors that influence
treatment decision.



Ricketts analysis




In 1972 Ricketts
proposed a
posteroanterior
analysis.
The
measurements
used in this
analysis are
given in the
diagram.






1.
2.
3.
4.
5.

This analysis includes clinical norms of
measurements used.
Measurements , in this includes 15 factors ,
that are grouped into 5 fields.
Dental frontal problem
Maxillomandibular relationship
Dentoskeletal relationship
Craniofacial relationship
Inner structural problems


Field I Dental-frontal
problems
 1. Molar relationship (left and
right):
 Molar relationship involves
the distance between the
buccal surfaces of the
maxillary and mandibular first
molars, measured at the
level of the occlusal plane.
 Normal value: maxillary
molar 1.5 mm buccaly.
 Standard deviation : ±1.5mm




Interpretation: This measurement describes the
molar relationship on the transverse plane.
Lower or negative values indicate a cusp-tocusp molar or lingual cross bite, respectively.
Values higher than +3 mm correspond to buccal
cross bites.


2. Inter molar width:
 The distance between the
buccal surfaces of the
mandibular first molars
measured at the level of the
occlusal plane.
 Normal value : 55mm. For
boys and 54mm. For girls.


Standard deviation : ±2mm.



Interpretation : measures
the arch width in milimeters
at level of first molars.

3. Intercuspid width :
 Distance between the cusps of
both mandibular cuspids
measured at the occlusal
plane.
 Normal value:22.7 mm at age
7 (non erupted teeth). The
distance widens 0.8 mm per
year until age 13 when it
reaches the adult value of 27.5
mm.
 Standard deviation : ±1.5mm.
 Interpretation : describes the
coincidence or lack of
coincidence of the denture
midlines.

4.Denture midline :
 Distance between the
maxillary and mandibular
dental midlines.
 Normal value: 0 mm.
 Standard deviation:
±1.5mm.
 Interpretation: Describes
the coincidence or lack of
coincidence of the
denture midlines.

Field II Maxillomandibular
relationship :
5. Left and right maxillomandibular
width:
 The distance between the maxilla
(point J) and the frontal facial
plane (Z - AG).
 Normal value : 10mm. For an
patient aged 8½ years.
 Standard deviation : ±1.5mm
 Interpretation : indicates the
transverse development of the
maxilla, useful for the differential
diagnosis of crossbite.



Z

J

AG

6. Maxillomandibular midline :
 The angle formed between
the midsagittal plane and the
ANS-Me plane.
 Normal value: 0°.
 Standard deviation: 2°.
 Interpretation: Determines the
mandibular midline deviation
with respect to the midsagittal
plane. This asymmetry might
be the consequence of
functional or skeletal
problems.

Z

Z

Field III : Dentoskeletal
relationship
7. Molar to both jaws (left and
right)
 Distance between the buccal
surface of the mandibular first
molar and the frontal
maxillomandibular plane (JAG).
 Normal value : 6.3mm. For an
average boy at age 8½.
 Standard deviation : ±1.7mm.
 Interpretation: An increased
measure indicates the
likelihood of a buccal
mandibular expansion.



J

AG

8. Dental midline to
maxillomandibular midline :
mandibular incisors midline
and the maxillomandibular
midline (ANS-Me).
 Normal value: 0 mm.
 Standard deviation: ±1.5 mm
 Interpretation: Relates the
mandibular midline to the
maxillomandibular midline. An
increased value indicates
deviation of the mandibular
midline of dental origin

9. Inclination of the occlusal plane :
 Difference between the
measurements from the Z-Z line
to the occlusal plane at the level
of the left and right molars.
 Normal value : 0mm.
 Standard deviation : ± 2mm.
 Interpretation: A value out of the
norm is due to an inclination of
the occlusal plane. It should be
taken into account because it
might be the result of skeletal
asymmetry and possible TMJ
disorders

Z

Z

Field IV : Craniofacial
relationship
10. Postural symmetry :
 Difference between angles ZAG-ZA on left and Z-AG-ZA
on right side.
 Normal value: 0°.





Standard deviation : ± 2°.
Interpretation: Used for the
diagnosis of asymmetry. It
can easily be distorted due to
an incorrect position of the
head when taking the
radiograph (lateral rotation).

Z

Field V : Inner structural
problems
11. Nasal width :
 The maximum width of the
nasal cavity.
 Normal value: 25 mm at age
8½. It increases 0.7 mm per
year.
 Standard deviation: ± 2 mm.
 Interpretation: Used for the
analysis of the airways.
Sometimes mouth breathing
might be due to a narrow nasal
cavity or to insufficient
transverse growth of the
maxilla.


12. Nasal height :
anterior nasal spine (ANS)
and the Z - Z plane.
 Normal value: 44.5 mm at
age 9, increases 1 mm per
year



Standard deviation : ± 3mm
Interpretation: Like nasal
width, this measurement
describes the nasal cavity.

z

13. Maxillary width :
 The distance between J
points.
 Normal value: 62 mm
at age 9. It increases
0.6 mm per year.




Standard deviation: ± 3
mm.
Interpretation: Indicates
transverse maxillary
growth and should be
taken into account for
planning and evaluation
of palatal disjunction

J


14. Mandibular width :
 The distance between
points AG and AG.
 Normal value: 76 mm at
age 9. It increases 1.4
mm per year.




mm.
Interpretation: Used for
the study of mandibular
morphology


15. Facial width :
 The distance between
points ZA and ZA.
 Normal value:116 mm
at age 9. It increases
2.4 mm per year.




mm.
Interpretation: Used to
describe facial
morphology.


HEWIT ANALYSIS


According to this method (Hewitt, 1975), analysis
of craniofacial asymmetry is performed by dividing
the craniofacial complex in constructed triangles,
the so-called triangulation of the face.
















The anatomical points
used are shown in figure.
1. Sella
2. Medial extent of orbit
3. Inferior extent of orbit
4. Condylar point
5. Mastoidale
6. Anterior nasal spine
7. Zygomatic arch
8. Upper molar point
9. Incisor point
10. Gonion
11. Menton





The two longitudinal axes
representing the midline points of the
maxillary and mandibular regions are
constructed.
Axis X : which represents the middle
third of the face is formed by joining:
sella, anterior nasal spine and
bisectors of lines joining the medial
extent of orbits, right and left orbitale,
right and left mastoidale, bilateral
zygomatic points, and right and left
molar points.

(X midline axis of maxillary region
N midline axis of mandibular region)




Axis N : which represents the
lower third of the face is
formed by joining : menton
and bisectors of lines joining
condylar points and bilateral
gonial points.


The angle of divergence of
the axes is proportional to
the degree of asymmetry
between the middle and
lower third of the face.
 The angle between the two
axes can be bisected to
give the arbitrary anatomical
axis of the face.
(AA Anatomical axis of face)



Method of triangulation




The reference points already
described were plotted and the
following triangles drawn on
both sides of the tracings:
A) Cranial base region:
Between the extreme upper
extent of the head of the
condyle, extreme mesial extent
of the head of the condyle and
sella to represent the cranial
base region;



B) Lateral maxillary region:
Between sella, mastoidale and
the root of the zygoma
representing the lateral maxillary
region;



C) Upper maxillary region:
Joining sella, anterior nasal
spine and the root of the
zygoma representing the upper
maxillary region;





D) Middle maxillary region:
Drawn between the root of
zygoma, upper molar points
and the anterior nasal spine
representing the right and left
middle maxillary regions;
E) Lower maxillary region:
Joining anterior nasal spine,
upper molar points and the
point of intersection of a line
drawn between the bilateral
upper molar points and the
arbitrary anatomical axis
lower maxillary regions;





F) Dental region: Drawn between
upper molar points, upper incisal
point and the point of intersection
of a line joining the upper molar
points and the anatomical axis
dental regions;
G) Mandibular region: Drawn
between the condylar points,
gonion, and menton to represent
the mandibular component of the
fact


 The

area of the respective triangles are
calculated for the component areas of the
face and compared for both the left and right
side.


Sassouni analysis
1. Upper Face and Cranial Base
2. Mid Face
3. Lower Face

Landmarks
 Upper face and Cranial Base






Roof of Orbit (RO)- Uppermost
point on the roof of the orbit
Lateral Orbitale (LO)Intersection point between the
external orbital contour laterally
and the oblique orbital line.
This represents the upper face
breadth.

RO

RO

 Mid face




Maxillare (Mx)- Maximum
concavity on the contour of the
maxilla between Malare (Ma)
and maxillary first molar.
Zygoma (Zyg)- Most lateral
and superior point of the
zygomatic arch.


 Lower face








Mastoidale(Ms)- lowest point
on the contour of mastoid
process.
Gonion (Go)- Intersection of
posterior border of ramus and
inferior border of mandible.
Menton (Me)- Lowermost point
on the contour of the chin.
This represents the mandibular
breadth.

 Construction of planes


Supraorbital plane is constructed
by joining points RO to RO



Bizygomatic plane is constructed

by joining points Zygoma (Zyg) to
Zygoma (Zyg)


Bimastoid plane is constructed by
joining points Mastoidale (Ms) to
Mastoidale (Ms)



Bigonial plane is constructed by
joining points Gonion (Go) to
Gonion (Go)


Symmetry


Trace the supraorbital line, the
lateroorbitale-to-lateroorbitale
(LO) line, the bizygomatic line,
the bimastoid line, and the
bigonial line



In an ideal situation all these
lines are parallel.


Symmetry


Symmetry of face in transverse
direction is assessed by
dropping a perpendicular to the
mid point of these lines.



When they are not parallel,
select the three planes that are
the most nearly parallel. From
their midpoints drop a
perpendicular and assess the
transverse symmetry of the face.

Position of upper first
molars


A line connecting LO (lateroorbitale)
and Mx (maxillare) is drawn and
prolonged downward.



The buccal contour of the maxillary
first permanent molar should be
tangent to this line, with a normal
variation of 2mm.



This is a guide, especially in crossbite
cases.


Limitations of posteroanterior
cephalometry






The main problems are related to the absence of
well-defined, stable (or relatively stable) structures
for the superimposition of the subsequent
cephalometric tracings.
Measurements used are subject to errors that may
be related to the X-ray projection, the measuring
system, or the identification of landmarks.
Difficulty in reproducing head posture, difficult in
identifying landmarks because of superimposed
structures or poor radiographic technique, these
factors also contributes in limiting the use of
posteroanterior cephalometry.

 Case



analysis

Patient name: Vaishali Asole
21 yrs female

Grummons analysis


Grummons analysis :
1. construction of four horizontal
planes
 Z-Z plane
 ZA-ZA plane
 J-J plane
 Parallel to Z plane through
menton
 Not parallel, asymmetry in
zygomatic region
2. MSR through Cg-ANS
3. Mandibular morphology
analysis – two triangles, CoMe-Ag on right and left side
compared

Cg
Z

Co

ZA

J
ANS
Ag


Me

4. Volumetric comparison
 Two polygons formed by
Co-Ag-Me-the intersection
with a perpendicular from
Co-MSR are compared with
computer program.
Co
5. Maxillomandibular
comparison of asymmetry
 Four lines from Ag, J
bilaterally, and from Cg- J ,
Cg – Ag
Ag
 If symmetry is present four
triangles become two.
 Asymmetry in maxillary
region.

Cg

J

Me

6. Linear asymmetry analysis
 Linear distance to MSR and
vertical difference of
perpendicular projection of
Co, NC, Ag, Me to MSR .
 Vertical discrepancy lies
with Co, J, and NC region.
7. Maxillomandibular relation
 Distance from buccal cusp
of first molar to the J
perpendicular, lines Ag-Ag
and ANS – Me constructed
to reveal dental
compensation for any
skeletal asymmetry.

Co

NC
J
Ag

Me

Ricketts analysis
Field I
1. Molar relationship
 Buccal surfaces of first
molar at the level of occlusal
plane.
Patients value- 1mm
Normal – 1.5mm ±1.5mm
No presence of crossbite
2. Intermolar width
 Distance between the buccal
surfaces of mandibular first
molars at occlusal plane.
Patient value – 55mm for boy
Normal -55mm ± 2mm for boy
Arch width in molar region is
normal



3. Intercuspid width
Distance between the cusps
of both mandibular cuspid
at occlusal plane
Patient value 21mm
Normal - 27.8mm
Lack of coinciding denture
midline
4. Denture midline
Patient 1.5mm
Normal 0mm ±1.5mm
Normal, within in range.

Field II
5.Left and right
maxillomandibular width
 Distance between J and ZAG Z-AG plane.
Patient value- left-16mm,
right-14mm
Normal – 10mm for an
average patient aged 8½
years.
6. Maxillomandibular midline
Angle between midsaggital
plane and ANS-Me plane.
Patient value- 0°
Normal- 0° ± 2 °
Normal

Z

AG


Field III
7. Molar to both jaw
 Distance between the
buccal surfaces of
mandibular first molars and
J-AG plane
Patient value left- 12mm
right – 7mm
Normal – 6.3 mm for an
averaged boy at age 8½
years.
8. Dental midline to
AG
maxillomandibular midline
 Distance between
mandibular incisor midline
and ANS-Me plane
Patient value 2mm
Normal 0mm ±1.5mm
Midline is shifted.


J

ANS

M

9. Inclination of the occlusal plane
 Difference betweeen measurement
from Z-Z line to occlusal plane at
the level of right and left molars
Patient value – left- 72mm right –
65mm
Normal – 0mm ± 2mm
Difference is 7mm , asymmetry
present due to skeletal asymmetry.
 Field IV
10.Postural symmetry
Difference between angles Z- AG-ZA
on both sides.
Patient value- left - 10° right – 10°
Normal - 0° ± 2 °
Asymmetric face.

ZA

Z

AG


Z

Field V
11. Nasal width
NC-NC
patient value- 24mm
Normal – 33.7mm
(for age 21 year)
Narrow nasal cavity
12.Nasal height
Distance between ANS
and Z plane
Patient value- 61mm
Normal – 56.5mm
(for age 21 years )
Nasal height is short



Z

Nc

13. Maxillary width
Distance between J points
Patient value – 65mm
Normal – 69.2mm
(for age 21years).
constricted maxillary region
14. Mandibular width
Distance between points AGAG
Patient value – 88mm
Normal – 92.8mm
(for age 21 years).
constricted mandibular
region

J
AG


15. Facial width
Distance between
points ZA-ZA
Patient value- 103mm
Normal : 142.8mm
(for age 21 years).
Constricted
interzygomatic width

ZA


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