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Orthodontist works primarily in the
occlusal plane of space. Advent of radiographic
cephalometrics have planned the treatment
modality in two dimension space,
Currently, the lateral cephalometric head films is
used in many respects to the exclusion of record
that define the third dimension.
Burstone (1961) introduced a new
procedure called occlusogram (positive print 1:1
photographs) and with the help of lateral
cephalometric head films it is now possible to
make treatment plan in all 3 dimension.
“An occlusogram is a 1:1 reproduction of the
occlusal surfaces of plaster models on a sheet of
acetate tracing paper.”
Photographic technique - Introduced by
Burstone; 1961, producing positive - print 1:1
photography of dental casts and tracing was
done with the help of photograph.
Photocopier technique - Introduced by
Yen. Photocopy of models are taken and then
they are traced and digitized.
TYPES OF OCCLUSOGRAMS
Manual eye viewer technique – Introduced by
White, describes a device called an occlusal tracer,
which makes a tracing of the teeth directly from the
model. (JCO, Feb 1982)
Computerized occlusogram - Introduced by
Burstone, 1:1 photograph is taken and scanned on
to which the points are digitized. (JCO, August 1979)
• Individualized Arch Forms: The occlusal
shape of each tooth can then be traced in an
ideal position on this basic arch, and a
customized ideal lower arch form can be
constructed and used throughout treatment.
White: JCO, Feb
Arch Length Discrepancy Measurement: The
occlusogram also permits the clinician to make
highly accurate and reliable arch length discrepancy
measurements by superimposing the idealized lower
arch form on the original.
Occlusal Simulations: Marcotte and Burstone
suggested setting the maxillary teeth around an
idealized lower arch form so that it would be
possible to do an occlusal simulation, or what is
known as a "set-up": without the time and
inaccuracies inherent in a plaster model technique.
Occlusal simulations permit the orthodontist to
quickly see if the maxillary teeth even have the
possibility of occluding with the lower correctly.
Evaluation of Various Treatment Plans: The
orthodontist can try any alternative he can think of
without risk or harm to the patient. Once a decision
is made regarding the diagnosis and treatment plan,
the orthodontist can implement this plan with a high
level of confidence.
To compare malocclusions with occlusogram
To formulate accurate tooth-size discrepancies.
Many clinicians prefer using diagnostic model
setups of standard Bolton measurements, but
setups are time consuming and difficult to
master. Occlusogram set up gives accurate tooth
JCO, July 1992
To construct ideal and individualized arch forms.
Nature arranges teeth in arcs through various
forces. An ideal arch selected at the beginning can
provide a template for arch wire construction
throughout treatment. These arch wire patterns
bring a coherence and consistency to arch wire
construction that is difficult to achieve by any
To create occlusal simulations.
To evaluate various treatment plans.
To make accurate measurements of arch
length discrepancy (ALD).
Although occlusograms have been used by a
few orthodontists for several years, there have been
no published norms or guidelines.
Marcotte published an excellent paper
regarding the clinical significance of occlusograms
In 1978, White illustrated how occlusograms
could be used for arch form determination and arch
length discrepancy measurements.
Occlusograms of twenty-four untreated
normal adult Class I occlusions were made at the
University of Connecticut using Dr. Burstone's
photographic technique. The measurements on
this sample of occlusograms leads to some
suggested guidelines for those who want to use
Each upper tooth touches two lower teeth below it,
with the exception of the last upper molar, which
has only the last lower molar to bite against.
The biting edge of the upper anterior teeth lies in
front of the biting edge of the lower anterior teeth
by an average of .7mm (anterior overjet).
The upper posterior teeth extend beyond the lower
posterior teeth by an average of 2.3mm on each
side (posterior overjet).
Typical ideal normal Class I occlusogram.
The upper bicuspids are wider than the lower
bicuspids by an average of 1.9mm on each side
(bicuspid lateral overjet).
The upper molars are wider than the lower molars by
an average of 1.4mm on each side (lateral molar
A key to firm static occlusion is the width and
position of the maxillary lateral incisors. If these teeth
are positioned correctly, they will extend at least to
the middle of the mandibular cuspid. This will insure
that the maxillary cuspid will be in proper occlusal
position, contacting the lower first bicuspid. If the
maxillary incisors are not wide enough to permit the
lateral incisors to engage the mandibular cuspids
properly, it will be impossible to achieve a firm Class
I occlusion without spacing between the upper
TYPES OF ARCH FORMS
JCO-Nov 1978: White
There are four currently popular formulae for arch
• Bonwill-Hawley formula,
• Brader arch forms,
• The Catenary arch design, and
• Rocky Mountain Data Systems computer-derived
Bonwill-Hawley Arch Design:
• Based upon the combined mesiodistal widths of
the incisors and cuspids.
• Arc of the anterior teeth relates an equilateral
• Largely been discredited, but it is still widely
• The shape of an ideal arch wire from an
orthodontic supply company will most likely be
of the Bonwill-Hawley design.
Bonwill-Hawley Arch Design:Bonwill-Hawley Arch Design:
Brader Arch Design:
• Known as trifocal ellipses.
• Based on arch width at the second molars as
measured at the facial, gingival surface.
• Brader arch adapts to the facial surfaces of the
teeth and all of the forms are alike in shape.
They differ in size as dictated by the widths at
the second molars.
Brader Arch Design
The maxillary arch form is always one size larger
than the mandibular and coordination of working
archwires throughout treatment is greatly
The main clinical criticism of the Brader arches is
that when those forms are followed, there is often
severe narrowing in the cuspid areas .
Typical narrowing of cuspids treated with Brader arch forms.
Catenary Arch Design:
• Determined by intermolar widths, but measured
from central fossa to central fossa.
• Curve which results when a fine chain is
suspended at its two ends.
• Described as a central core or central perimeter
around which the teeth arrange themselves.
• Catenary's popularity is the work of MacConaill
Catenary Arch Design:
• MacConaill and Scher acknowledge some deviations
from this "pure form", but suggest that these are due
to pathological forces that occur during eruption of
the teeth and subsequent alveolar development.
• Burdie and LillieH found that a basic bony arch is
established as early as 9.5 weeks in utero and they
suggested that this basic arch was of a catenary
design. However, their own evidence shows many
arches which were arranged outside of the catenary
form and certainly this is before any pathological
force has disturbed the catenary "pure form ".
• RMDS is based upon measurements taken from
intermolar width, intercuspid width, and arch
depth as measured from the facial surface of the
incisor to the distal surface of the terminal molar.
• This allows the computer to be programmed with
Cartesian x and y coordinates that are necessary
for a two-dimensional, computer-derived formula.
Facial type is also considered in this arch
All of these techniques have one common area
of agreement, the anterior part of the dental arch is
part of a curve. This curve has been described as
1. an ellipse,
2. a parabola,
3. part of a trifocal ellipse,
4. and a catenary.
A study was undertaken to see how a collection of
ideal, untreated arches conformed to the predetermined
arch forms of the most popular formulae, and to come
to conclusions, if possible, about how reasonable, ideal
arch forms can be derived for individual patients.
Dental casts of twenty-four orthodontically
untreated, superior, adult occlusions were collected.
Tracings of the teeth were made on acetate paper and
overlays were constructed and superimposed.
RMDS recognized the possibility of arch
asymmetry and changed its computer analysis method to
use a different mathematical curve for each side of the
Clinical Technique Determining
Physiologic Archforms – Oakes method
Mandibular model with all permanent teeth
present provides the best basis for construction of a
correct or "physiologic" arch form.
This technique takes less than three minutes. For
the best symmetry, trace first from the midline to the
left, then flip the acetate over and trace from the
midline to the left on the opposite side.
1. Attach cake-decorating beads, representing the
ideal bracket positions, to the mandibular model
2. Place a clear piece of glass or plastic over the model,
or place the model in an occlusogram jig and overlay
the jig with acetate.
3. Viewing the model from directly overhead, transfer
the bead positions to the acetate, glass, or plastic with
a permanent marker.
4. Remove the acetate, glass, or plastic from the model,
and connect the dots as symmetrically as possible.
Some smoothing is often needed to obtain symmetry
in cases with anterior crowding.
Place the lower arch wire directly over the traced arch
form. Bend the upper arch wire to lie outside the
traced arch form.
Physiologic archforms are difficult to construct in
cases where there is severe intercanine constriction. If
the original intercanine width is maintained, the arch
form will be "squeezed" in the cuspid region.
Although the principle is sound, such an arch form
would be unacceptable. In these cases, expansion is
necessary and extended retainer wear must be
Although preformed arches have been made using
various geometric or computer-generated data, the fit
to an individual mandibular model is highly variable.
The simple technique described above produces
individualized physiologic archforms that reduce the
potential for relapse of orthodontic expansion.
• Photographic Technique:
The dental impressions are made, casts
Wax jaw registration be made in centric
This wax centric relation registration is then
placed between the dental casts while the
posterior borders of the casts are trimmed and
made flush with each other.
TYPES OF OCCLUSOGRAMS
Study model set-up, Black-and-white camera on horizontal photo copy stand,
A registration groove is placed in the backs of
both casts simultaneously by means of a custom-
made dental cast scriber.
The casts have thus been trimmed with their
backs mutually perpendicular to the occlusal
plane and to the palatal midline and have also
been scribed to permit the positive-print,
occlusograms to be oriented laterally.
The casts are then finished and polished in the
Central groove cut into
the backs of models.
Triangular file used to cut central
Occlusogram camera assembly consists of a 4 by
5 inch box camera, a dental cast stage, two 375-
watt floodlights, and a hinged Plexiglas plate.
The camera is mounted on a sliding track, so that
the distance from the edge of the stage can be
adjusted and fixed to produce a 1:1 magnification.
For this particular installation a 210 mm lens is
found to be satisfactory.
The dental cast stage has an adjustable guide onto
which fit the registration grooves on the backs of
the dental casts.
Occlusogram set up. This set up can produce archival-quality occlusograms
on positive print film.
Lower dental cast on the registration track of the occlusostat. The registration
lines can be seen on the leading face of the occlusostat. The occlusal surfaces of the
cast have also been made flush with the leading edge of the occlusostat.
Registration dots which are located in the leading
edge of the stage will also be recorded on the
With a fine-grain positive film placed into film
cassette and with both flood lights focused on the
dental casts, a typical the exposure is made.
Processed according to manufacturer's directions,
maxillary and mandibular occlusograms are
produced at 1:1 magnification.
Using the registration dots on the leading edge of the
stage as reference points, both occlusograms are
registered on these dots and permanently fixed at the
bottom edge with a noncracking type of tape (for
example, Mylar tape).
Since the positive print film is transparent, the
existing occlusal relationships in centric relation can
be seen when the occlusograms are folded over. For
most treatment procedures, however, an occlusogram
tracing is required.
For this occlusogram tracing, acetate paper is
placed over the occlusograms and the maxillary
and mandibular teeth are outlined, showing the
gingival tooth contours, incisal edges, buccal cusp
ridges, central grooves, and cusp tips.
Also traced are the palatal rugae, the midpalatal
raphe, the fovea palatinus, and the registration
Upper and lower occlusogram tracings. Both are shown with the
registration dots on the backs and the registration lines (R). A mid saggital
reference line is also drawn on the upper occlusogram tracing
Both the occlusogram tracing are assembled on the registration dots.
• Yen makes a photocopy of the model and then traces
or digitizes the photocopy.
• Yen's method is easier than the other two, but the
photocopying can introduce varying degrees of
distortion because the models are three-dimensional.
• This distortion can be limited to about 1 -2 percent
enlargement if the models are placed on the surface of
the machine so that the least amount of shadow is
projected to the copy.
Photo copier method
Photocopy of upper and lower models, with right, left, and midline
The following is a simple clinical method of
using occlusograms to evaluate space
requirements, while taking into account lateral
and frontal treatment planning objectives. Like
Yen's technique, it uses a photocopier, but the
effect of a small amount of photocopier
distortion is minimized by the measurement
Occlusograms in Orthodontic
FABER; JCO Jul 1992
Make a set of orthodontic study models with a
centric relation wax bite registration.
Trim the backs of the models with the bite
registration in place, so that when they are placed
on their backs they are in centric relation.
Make three marks on each
model with the backs in centric
relation and the teeth in
occlusion- on the right and left
sides in the buccal segments
(usually the molars) and at the
Then, extend the marks over the
occlusal surfaces so they will
appear on the photocopy.
Triangular file used to cut
central orientation groove.
Make a photocopy of the models.
Photocopy of upper and lower models, with right, left, and midline
Trace both arches along with the
reference marks. Mark the right
and left sides.
With the frontal cephalogram
and the clinical examination,
establish the post-treatment
midline for the mandibular arch
and mark it with an arrow on the
lower occlusal tracing.
A. Pretreatment lateral tracing showing AB to occlusal plane. B. Pretreatment
anteroposterior tracing with apical base midlines marked.
Use an arch symmetry
chart to establish
symmetry of the lower
arch from right to left.
Mark the midline and
reference line. Lower occlusal tracing placed over arch
symmetry chart to establish midline and
perpendicular reference crosshairs.
Place the upper tracing
over the lower, aligning
the reference marks
marked on the occlusal
surfaces. Transfer the
crosshair reference lines
from the lower
occlusogram to the
Determine the desired post-treatment position of the
lower incisor on the lateral cephalometric tracing.
Measure the amount of facial or lingual movement,
and mark this amount along the vertical reference line
on the lower occlusogram.
Mark the desired post-treatment cuspid width on the
Treatment objectives for incicors and
Pretreatment lateral cephalogram
When the anteroposterior position of the denture
bases is influenced by growth, facial growth
rotations, changes in the cant of the occlusal
plane, and/or surgery, these positions should be
anticipated for the period of treatment and
incorporated into the occlusogram tracings.
Treatment objectives for
orthodontic phase (blue)
and surgical advancement
of mandible (red).
The amount of movement is calculated by
measuring the projected AB to occlusal plane
before and after changes.
Completed occlusograms showing
archforms in red and space
requirements in blue. Dashed line
indicates projected change in AB to
occlusal plane after surgery.
This can be marked on the occlusogram, and
the lower tracing can then be slid forward to the
new line to evaluate the arch width required for
good posterior occlusion after changes.
Determine the desired molar movement from the
axial inclinations on the frontal cephalogram, from
the study models, or from clinical examination of
the buccal and gingival tooth contacts.
Mark the desired molar width on the lower
Using a French curve (or a template if desired),
draw the treatment-planning archform by
connecting the incisor, cuspid, and molar reference
Place the upper occlusal tracing over the lower by
aligning the reference crosshairs, and draw the
planned upper archform, allowing for buccal and
Measure the mesiodistal tooth widths directly
from the models with bow calipers, then mark off
these widths on the occlusogram archforms.
Work distally from the midline, and be sure to
measure the widths on both sides of the arch; there
are often significant tooth-size differentials from
right to left.
Direct measurement of models using bow calipers.
Planned archforms drawn in red, and mesiodistal tooth widths marked off in
Blue posterior lines perpendicular to archforms show space required to meet
This technique demonstrates the versatility and
simplicity of occlusograms when used for space
analysis and coordination with treatment planning
in the other planes of space.
Reliability of Measurements
from Photocopies of Study Models:-
MICHEL JCO,1992 Oct
Ten sets of study models (20 occlusal surfaces) were
photocopied on a Canon PC-25 photocopier.
Each model and its photocopy were then measured by
the same operator, using an electronic digital caliper.
The following measurements were recorded:
1. Total arch length (the sum of all maxillary and
mandibular individual tooth widths)
2. Intercuspid width
3. Intermolar width
There was little difference between the actual
models and the photocopies in measurements of
arch width. However, there was a substantial
difference in the measurements of total arch
Photocopies of models appear to be valid for:
Comparing pre- and post-treatment archforms
Checking original tooth rotations or the initial
arch form during treatment.
Producing occlusograms for demonstration
Photocopies may be less precise for:
Measuring arch length
Producing occlusograms for space analysis
The most primitive technique for making
accurate 1:1 occlusal reproductions is to trace
the occlusal surfaces of the teeth onto a clear
1/8" plastic sheet that is secured against the
Since the eye of the viewer is the camera,
the viewer's head must not be moved while
tracing both sides of the model. With a
minimum of practice, highly accurate tracings
can be made with inexpensive materials .
Manual eye viewer –occlusogram
Manual method: Occlusal map maker.
Computer-Aided Space Analysis
YEN- JCO, Apr 1991
Make a photocopy of the upper and lower study
Digitize the key landmarks from the photocopy. (If
necessary, allow for any enlargement introduced by
Run the program and print out the data.
Printout of space analysis and computer-generated arch form.
Horizontal lines in arch form indicate arch widths.
Computerized arch form is made by simply
connecting the most mesial and distal points of each
tooth from second molar to second molar.
Each arch is divided into three segments- anterior
(B + C) and posterior (A and D).
The "required space" for each segment is the sum of
the tooth sizes in that segment; the "available space"
is the total width of the segment.
Each arch is divided into anterior
(B + C) and posterior (A + D)
segments for space analysis.
Computer produces arch form by
connecting most mesial and distal
points of teeth.
Digitizing the points of the 1:1 occlusal
photograph of the model give the both measurements
and a diagram of the tooth positions . The computer
does a setup.
Points are digitized at the mesial and distal
contacts and the tips of the buccal cusps of the lower,
and the functional cusps on the upper will be the tips
of the lingual cusps. The computer draws the teeth.
Digitizing points on a 1:1 occlusal photograph. Occlusogram.
Computer-drawn original and final arch forms. Arch length
inadequacies and movement required of each tooth are
calculated and shown.
The computer calculates the variations from the
mean in tooth size. The reason for seeing this on the
screen at this time is to find out if there are major
tooth size differences and make a decision on
extraction, or to point out a mistake in digitizing.
Now, the first question the computer asks is if the
right molar should be moved so that we can determine
the geometric midline. There are other determinants of
the midline, including what looks good for the face
and also if there is any skeletal discrepancy anteriorly.
The geometric midline is a point right in the
center of the arch if we like the relative positions of
the posterior teeth on the right and left sides.
So, the computer asks whether the buccal
segments to be moved back in respect to the other,
just to equalize their axial inclination or their
position. It will then calculate where the center of the
arch is — the geometric midline.
Now the computer will first of all draw the
original malocclusion on which you see certain
control points which the orthodontist decides.
Orthodontist decides what the width should be. He
digitizes where he wants the lower incisor to be. This
is all individualized. All the computer does is make
it easy to handle.
Final upper occlusal plot.
Now, we have the
new arch form
constructed. Both the
original and final arches
are shown on the screen.
The anterior part of the arch is a segment of
a parabola, so it fits a parabola between the points
that clinician select. There are enough control
points, so that each arch form is individualized for
The clinician decides where to position the
midline, the computer stores that decision and it
then calculates the arch length inadequacy. Also,
the computer graphically shows where each tooth
will be in the individualized arch.
Control points are placed one in the midline
point, how far backward or forward you want the
incisor. Clinician also selects the width points where
he thinks the tips of the cuspids should be, and the
mesiobuccal cusp of the first and second molars.
The clinician must make those decisions. No
computer can make them. However, lateral treatment
planning program helps with the decision of where
the lower incisor goes.
Now, the computer asks if he want to see a
hard copy. Normally hard copies are made as a
permanent record at the end. The printout is
three times life size, so he can see what the
relationships are in detail. The longer lines
represent the mesials of the first molars .
Computerized setup. Lower teeth (red) and upper teeth (green).
Orthodontist can choose to extract and see the
"treated case" on the screen. If he doesn't like the
results, he can go back and go through another
He can try one with different extractions or
A number of different treatment plans can be
tried to arrive at the best possible one.
Manual and computer-aided space
analysis: A comparative study.
Schirmer, AJO;1997 Dec
The computer-aided measuring system is
reliable, but accurate mesiodistal measurements
cannot be made from photocopies of dental models.
Manual measurements that use a calibrated gauge
produce the most accurate, reliable, and reproducible
Video Printing in Orthodontic
BURKE: JCO; Feb 1987
The Mitsubishi P5OU Video Printer measures about
Video printer used to image study models, with sample print..
The printer can “ grab” a still picture of
anything that appears on the TV monitor when
the “ print” button is pushed. This triggering can
be done at the printer or by a remote-control
extension cord switch.
Video cameras or color camcorder, which has
self-contained playback capability, can be
connected directly to the video printer for
making extraoral pictures.
Close-up lenses are more adaptable. These
optical glass “ magnifiers” come in various diopter
strengths and attach to the lens. Close-up lenses
permit any type of magnification— for example, a
1:1 ratio for occlusograms.
Diopter lenses attach to camera lens for close-up focusing.www.indiandentalacademy.
Creating a video print is essentially the same as
conventional photography, with the added
advantage of immediate results for appraisal and
Facial images can be improved by using adjustable
photo reflector light stands with standard household
When you set up your system, trial and error will
determine the correct camera distance,
magnification, and lighting.
THE “3-D OCCLUSOGRAM”
AJO, Sep 1999: Foirelli
• The 3-D Occlusogram (3-DO) procedure includes
4stages, which are performed by different
components of the software:
• Image scanning and setting
• Occlusal view processing
• Lateral cephalometric processing
• Occlusogram construction
• The treatment goal can be produced either manually,
by means of 3-dimensional scanning equipment, or
by means of the software demonstrated above
coupled with a common flatbed scanner.
• The latter has the advantage that, after a rather short
training period, it is more rapid and more precise than
the manual method without requiring any special and
expensive equipment that the orthodontist does not
generally already possess.
Holograms as substitutes for
study casts. Harradine et al: AJO 1990
A hologram not only provides two-dimensional
information about an object, as found in photographs,
but also depth information. This transforms the image
of the object into three dimensions.
Plaster casts are mainstay of clinical
orthodontic records since many years but has
Fragile & prone for fracture
Bulky & expensive to store and transport.
Need keep for long periods.
Advantages of holograms
Schwaninger et al (1977) proposed potential
advantages of holograms as a substitute for study
Holograms are resistant to damage.
Better suited to transport by post.
Can be stored with patient’s clinical records.
Accurate measurements such as intercanine
width can be measured.
Significant consideration is the consequence of
incorrect occlusion of the models when the
holograms are being made.
Once made, a hologram cannot be adjusted as a set
of study casts.
Clinically useful holograms are therefore more
demanding in terms of clinical and laboratory
techniques than are study casts.
In a study by Harradine et al ( 1990 Aug AJO)
with four clinicians and 56 patients, three of the
clinicians found the holograms to be acceptable
alternatives to study casts in routine clinical
Current holographic cameras enable those who
are not experts to produce holograms very simply, but
careful clinical and laboratory techniques are required
to ensure that these holograms correctly record the
The Holodent system, a new technique for
measurement and storage of dental casts.
Martensson et al: AJO 1992 Aug
The system has a precision that is equal to
that of previously reported methods and may be
well-suited for studies of dental positional changes
in longitudinal materials of study models.
Holograms of dental casts may solve storage
problems by replacing space consuming plaster
Occlusograms offer us an accurate way to
measure, compare, and evaluate malocclusions, to
plan and forecast treatment, and to visualize
occlusal objectives. They do take time, but it can
be easily learn how to do them. The use of
photocopies removes the need for expensive and
Hoping that orthodontists will take one more
look at this valuable technique. The rewards to both
patient and doctor clearly make occlusograms a
worthwhile adjunct to our diagnostic