Videocephalometry /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
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DEFINITION
Video imaging technology is a method in
which orthodontist gathers facial
frontal,profile,and dental images and
modify them to project potential esthetic
treatment goals
(David .m .Sarver)

INTRODUCTION

The continued improvement in
orthodontic and surgical techniques
creates a greater demand for the
orthodontist to communicate with
the patient and other involved
professionals about the projected
treatment goals and outcome.

Experienced clinicians often
have a good mental image of
what they want to
accomplish with the
treatment,but the patient’s
ability to visualize or
interpret,and thus accept, the
plan has been limited.

Clear communication of treatment goals and
potential options of treatment are important
aspects of today’s concepts of informed consent
and clinical practice.
Orthognathic surgeries need clear
communication and attention.
A Pioneer oral and maxillofacial surgeon once
stated “Big Surgery, Big problems!”.

Computerized video imaging technology
offers a mutual visual template by which
dentists,orthodontists,oral and maxillofacial
surgeons,and plastic surgeons can effectively
communicate with patients and with each other.
Co-ordination of calibrated lateral ceph with
facial profile images permits precise measurement
of bony and dental movements, and through the
application of algorithmic prediction ratios,images
are produced that express the expected surgical
and/or orthodontic outcome

This improvement in visualization and
quantification can help to remove
some of the guesswork involved in
surgical treatment planning.


This topic covers the transition
from conventional treatment
planning to computer assisted
planning and how the merging of
technology and contemporary
dental and profile treatment
planning has occurred.



In a study by Kiyak(1982) he found that
53% of female patients and 41% of male
patients listed esthetics as a major factor in
their decision to proceed with orthognathic
surgery.

In a study by Saver et al (1988)of patients
whose surgeries were planned interactively with
video imaging,90% patients reported that the
final result was as good as or better than the
predicted image.

Video imaging technology has the potential to
touch almost every aspect of the orthodontic
practice.
Its advantages are






Diagnosis and treatment planning
Communication at consultations
Database management
Communication with other offices

EVOLUTION
There are 5 general methods of visualizing, planning
and predicting surgical orthodontic outcomes:
1) Manual acetate tracing “cut &paste” techniques
as described by Cohen, Mc neill et al and
Henderson.
2) Manipulation of patient photographs .
3) Computerized diagnostic and planning software
that produces a soft tissue profile “line drawing”
as result of manipulation of digitized structures of
lateral cephalometric radiographs.

4) computerized diagnostic and planning
software that integrates video images with
patients lateral ceph.
5) 3-D computer technology for planning
and predicting orthognathic surgery(moss et
al).He expanded on the early methods of 3-D
planning by including laser scanning to model
the soft tissue response to hard tissue
movements

3-D TECHNOLOGY


ACETATE TRACING OVERLAY METHOD

The most commonly used method in the
prediction of profile outcome with orthognathic
surgery is the use of acetate tracing
manipulation.
This was first introduced to orthodontists
in 1970’s.


METHOD
Cephalogram is obtained with patient’s
soft tissue and lips at rest.The hard and soft
tissue outline is traced onto a sheet of matte
acetate paper with a 0.5 mm lead pencil.
Tracing of incisal and cusp outlines of all
teeth &occlusal plane should be clearly visible.
Then simulated tracing done by simply
placing the incisors in normal overbite & over
jet relation &placing posterior teeth in occlusion

The planner retraces the profile outline,with a
ruler measuring the ratio of hard tissue and soft
tissue response and apply a BEST GUESS
Disadvantages:
Involves lot of guess work
Crude & time consuming
Trained and experienced orthodontists & oral
surgeons can make a mental image, but the
patients ability to interpret was much more
limited

Utilizing the prediction tracing. A. Desired orthodontic change in
the mandible. B. Desired orthodontic change in the maxilla. C.
Desired position of the teeth prior to surgery to allow desired
anteroposterior change at surgery. D. Superimposition showing
desired orthodontic change following surgery.

PHOTOGRAPH MODIFICATION
In an attempt to improve communication with
patients,this was proposed,as a method of
illustrating to the patient the soft-tissue results
of the suggested plan


METHOD
The photographs are physically sectioned;the
cut-outs represents the parts that will be
moved in the planned osteotomies and are
arranged to simulate surgical movements
Advantages: It gives the patient better
visualization of the profile changes than a
acetate tracing does.

Disadvantages:
 Does not permit change to soft tissue
contours that occurs with treatment
 Unavoidable gaps in photo have an
unnatural appearance
 An experienced clinician with artistic skill are
essential with this methodology

COMBINING PHOTOS WITH
CEPHALOGRAMS
Henderson in 1974 presented the idea of
combining cephalometric tracing with
sectioned transparent profile photographs
to assess predicted skeletal movements
and soft-tissue profile changes


METHOD: As described by kinnebrew et al
AJO1983
MATERIALS:An accurate lateral ceph taken in
centric relation,with relaxed soft tissues and
visual axis paralleling the horizon
35 transparent photo in slide
Radiographic view box
Vertical surface for projecting the slide
Acetate tracing paper & suitable lead pencil

TECHNIQUE:
The ceph is traced in the standard
fashion,including the hard and soft tissue
outlines
The 35 mm slide of patients profile
photo(transparent)projected onto view surface
The ceph tracing is overlaid onto photographic
image.the image is adjusted until the soft
tissue outlines coincide.exact parallelism is
difficult because of radiographic magnification

The facial features,including
ears,hairline,forehead,eyes,eyelid,nose,lips,chin
and neck are then traced onto a clean acetate
sheath with contoured shaded.
The image is then redrawn adjusting the
dysmorphic parts to the unchanged part of the
face to effect balance of the profile and to
restore normal contours.it is a composite tracing.

The composite tracing can be modified to
simulate dental and skeletal changes.Then, by
using the appropriate soft-tissue displacement
ratios,the overlying soft tissue can be artistically
contoured into its predicted position.
Disadvantages:


process is time consuming

 Magnification factor should be taken into
consideration

MANUAL METHOD OF PHOTO CEPHALOMETRY


ERA OF COMPUTERS
Initial uses of computers involved basic
image modification of profile images
obtained with either a
 Video or digital camera
 Conventional scanner
 Scanner which can take 35 mm slides

Computer assisted cut & paste movements
(morphing)were used to modify the image in an
effort to describe the anticipated profile or facial
result from dental or osseous movement
Advantages
 Proved to be useful in describing gross facial
changes expected with orthognathic surgery.

Disadvantages:
 Incapable to visualize the underlying dental
or osseous relation
 This is critical because functional correction
of malocclusion is our primary treatment goal
 This virtually dictates our need for
superimposition of the cephalometric
radiograph and the face.

PHOTOCEPHALOMETRY
It was a precursor to videocephalometrics.
In 1978 Hohl et al proposed a
photocephalometric technique for taking
cephalometric radiographs and photo images
that could be accurately superimposed.


TECHNIQUE
Involves taking a photograph and cephalogram
of the patient in the same position and from the
same distance.
The photograph negative could be enlarged
and accurately superimposed on the ceph to
allow visualization of the profile changes that
would occur with craniofacial osteotomies.


ACCURACY:
A study by Phillips et al investigated the
accuracy of photocephalometry.A grid was
placed at a position that corresponded to the
patient’s mid sagittal plane and then a camera
was mounted on a tripod that directly
corresponded to the ceph radiographic source.
Photograph and cephalograms of the grid were
taken and evaluated.

Study concluded that,this technique provided
images that could be superimposed to a
certain degree,enlargement factors between
cephalogram and photographs were of great
magnitude.
This reflects the need for development of
algorithms to further refine the predictability.

Advantages:
A more detailed visualization of soft
tissues in the frontal and lateral views
A more accurate analysis of soft to hard
tissue relationships,particularly of soft
tissue thickness.

Disadvantage:
The differences in the enlargement factors
between the photographic and radiographic
images are of such magnitude that the super
imposition of the two images is not feasible for
quantitative comparison of soft and hard tissue
anatomy.

THE EVOLUTION OF
COMPUTERIZED CEPH ANALYSIS AND
PROFILE PREDICTION

Cephalograms are 2-dimensional
representation of 3-dimensional anatomy.
All over the world orthodontists take ceph in
highly standardized form


Standard head position and orientation.
Standard object-source distance
Standardized radiographic enlargement
Digitization:
Digitization is process by which analog
information is converted into digital format.
Digital imaging may be done in two different
ways

Digital image may be scanned
Digitally produced
1) A digital image,either photo or ceph,may be
produced from the existing radiograph or
photograph by scanning it into computer or
the use of a mounted digital video camera.
Presently scanning is the least expensive option
in terms of costs.

2)digital image may also be produced through
digital photographs or radiographs.The digital
radiography uses a digital capture plate on
which image is immediately transferred to
computer storage.
 No need of processing
 Reduced exposure to patient
 Wave of future
 Highly expensive,&currently not available

The benefits of digitization of ceph are,
The laborious measurement of angle and
distances by the manual use of a protractor is
eliminated.
Once the ceph land marks are entered
through the digitizer measurement
calculations are performed virtually
instantaneously by the computer.This
eliminates vast amounts of time required in
the measurement.. And a added bonus ,the
errors are avoided

DIGITIZATION
Currently there are 3 methods for
cephalometric radiograhic analysis
1)hand tracing &direct measurement
2)direct computer digitization
3)indirect computer digitization


Hand tracing
A piece of acetate tracing paper is affixed to
the ceph and a 0.5mm lead pencil is used to
trace hard &soft tissue anatomy.Measurement
of desired angles and distances for analysis
are then performed by hand with the use of a
protractor/ruler.


Direct computer measurement
The ceph is placed on a digitizing tablet,and
the anatomy and anatomical points are
entered into computer through the use of an
electronic pen or instrument
Digitizing tablet: is made up of a fine
electronic grid that includes registration points
as fine as .009mm apart

Electronic pen:
Also called as potentiometer & is of two
types.pen type and cross hair cursor
Pen type:an electronic pen is activated to emit
signals when the tip of the pen is depressed
against the ceph.This closely resembles the
mechanical motion orthodontists are
accustomed to.


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Cross hair cursor: This potentiometer comprises
of two wires arranged in a cross-hair
pattern,which are imbedded into a glass
window.The electronic signal is emitted from the
junction of the wires.The points to be digitized
are identified by the clinician,the crosshair
directly placed on the point,and the
potentiometer is then activated with a button on
the instrument.An electronic signal is
emitted,picked up by the grid,and registered in
computer memory.

Advantages:
Once data entry is complete,the computer
can instantly reconstructs the data in the form
of conventional tracing or print out.
Many analysis made instantly


Disadvantages:
Instrument tends to block the view of the rest
of the film
Point identification very difficult
Glare from the glass


Indirect digitization
A video camera or scanner captures an image
of the ceph & stores it in computer.Once the
image is captured and stored in the
computer,image is then displayed on the
monitor and indirectly digitized via a mouse or
an on-screen electronic pen


Comparing hand tracing with
computer digitization
Richardson(1981) investigated the precision of
directly digitized ceph and hand traced
ceph.He concluded that there is not much of
difference in both methods in terms of
accuracy.
In a study by houston(1982),he concluded that
the errors associated between the two groups
was significantly insignificant.

Comparing direct digitization
with on screen digitization

In a study by jackson et al(1985 BJO),he
concluded that onscreen digitization method
is as good as manual tracing.There are
following factors which influence the image
seen by the clinician.


Distortion by the camera lens



Software distortion



Type of monitor


In a study by Sarver et al in which he found that
computer monitor is the most common source
for distortion
16%distortion on left side
11% distortion on right side
No distortion in center
He advocates to use flat screen monitor to
eliminate this.

Requirements for vcd

Also radiographic source,developing euipment,lightings,plain background.

Video imaging technique
There are two phases in video imaging
1.counseling phase
2.treatment planning phase


Counseling phase
Involves the use of facial or dental
image modification without any
quantitative aspect to the process.
It is simply a graphic way of
communicating ,concepts that are
difficult to present verbally.

For e.g,imaged pictures or smile banks could
be used to explain to patients how their teeth
will look like.
Procedure
Pre treatment profile modification
sessions may be performed with the patient
before full records are taken.in the counseling
phase profile image is gathered and displayed
on the computer screen, & profile changes
expected with surgery are illustrated through
the use of cut & paste tools

Which is present in most imaging
software packages.Cut & paste permits
image modification but does not offer
quantitative feedback.
The changes performed on the image
are displayed on the monitor may not be
duplicated in the surgical, procedure
because the surgeon does not know how
far facial and skeletal components were
moved to obtain the projected outcome
image.

As in all phases of profile analysis
and consultation, natural head position
is recommended
The following figure illustrates why
head positioning is important in imaging.


Difference in lateral rotation of head,foreshortens the nose

SNA-NORMAL
.

SNB-90


.

15 ROTATION OF PICTURE


The counseling and treatment planning
phases are explained along with a patient
example.
A adult female patient presented with a
chief complaint of her class II dental
relationship secondary to mandibular
deficiency.she was referred by her spouse
a dentist,and was considering mandibular
advancement to correct her class II
relationship.

Molar relationship


She had been ortho treated as a child with 4
bicuspid extn but was unable to attain class
I molar relationship.
she presented to orthodontists for
counseling to discuss her treatment options
but was unwilling to commit to surgery until
she had a clear idea of what she will look
like.


An initial profile image was captured and
displayed on compu screen for graphic
illustration of the facial changes that should be
anticipated with orthodontic decompensation
and surgical mandibular advancement.
The use of cut & paste art functions in the
software programme allows us to copy outlined
segments of the image to RAM for short term
storage and graphic movement.

The conseling phase is performed without
videocephalometric integration,but simulation of
the soft tissue reaction to the planned hardtissue movements(orthodontic and orthognathic)
can be performed.
It is done to communicate to the patient the
facial changes that would occur with pre-surgical
orthodontics and outcome of orthognathic
surgery.

procedure
First the initial image is captured and displayed
on the computer screen with selected ceph
analysis overlaid on the profile image.
Application of the ceph analysis to the profile
demonstrates the dental compensation and
mandibular deficiency present in this patient.

IMAGE OBTAINED
WITH VIDEO
CAMERA , STORED
& THEN DISPLAYED
FOR DIGITIZATION
AND ANALYSIS


Simulation of orthodontic decompensation of
maxillary incisors through torque and
advancement of upper incisors is then
performed using the cut and paste function.
Profile changes expected with maxillary
advancement in preparation for surgery are
illustrated by advancing the upper lip on the
profile image.
(Look worse before you look better)

This is in order to mentally prepare them
for the unmasking effect of
decompensation.
In the computer simulation, a box is
placed encompassing the upper lip and
copied to RAM.The box is then moved
forward by the mouse.The new position
reflects soft tissue reaction to
decompensation.

Click & drag


The next step is to simulate
mandibular advancement. A new
copy box is placed on the mandible
and copied to RAM.
This outlined portion is then moved
anteriorly to simulate mandibular
advancement

Click& drag


The mandible is moved forward ,the
amount estimated by the clinician to
correct the class II
This image simulates orthodontic
decompensation and correction of
mandibular deficiency & class II
malocclusion


The next logical procedure is advancement
genioplasty to improve chin projection.This
is simulated by outlining another template
on the chin,copying the section of the chin
to RAM and then moving the chin
anteriorly to an esthetically desired
position.

Click& drag

Simulation of genioplasty


The final profile created by image
modification effectively communicates the
anticipated effect of orthodontic
decompensation ,surgical mandibular
advancement,and advancement
genioplasty


final profile


Pre & post counseling photos


In this short preliminary visit the patient has
received graphic communication regarding the
potential facial changes that will occur during
ortho treatment & the anticipated outcome of the
proposed treatment plan.
After this phase of counseling, patients may
then decide whether they value the esthetic
changes & are reassured enough by the image
modification to pursue more comprehensive
treatment planning

Treatment planning phase
The treatment planning phase of video imaging
involves the integration of the facial profile image
with the ceph and calibrating it to profile video so
as to relate the underlying hard-tissue to
overlying soft-tissue. It allows quantification of
hard & soft tissue movements and to apply
algorithmic response ratios between the two to
project the soft-tissue reaction to hard tissue
movement.

Judgments can be made about the basic
changes needed for occlusal correction by
having the ability to see where the teeth are
in relation to the face.consideration can then
be given to what other procedures may be
needed to attain the facial and dental
aesthetic goals.


In the adult patient the computer projection
can be quite accurate.In the adult major
inaccuracy is the actual treatment itself.

In the adolescent the unpredictability of the
growth dynamics greatly diminishes the
predictive value of video cephalometric
projection.

procedure
The same patient example will be used to explain
the treatment planning phase.After the profile
image is captured, calibration procedures are
performed when the ceph is matched to video
image.
The computer can then perform algorithmic
calculations so that the movements on the video
screen are translated into real life terms.

A profile treatment planning template is created
by integration of the cephalogram, calibrated to
the facial profile, and displayed on the computer
monitor.
Profile projections(hard tissue movement with
appropriate soft tissue response)are drawn from
the computer data base & applied in algorithmic
fashion when the dental or osseous segments
are moved.

calibration
If the coordinated videocephalometric images
cannot be translated into real – life
measurements,then the treatment planning
process has no quantitative validity.
Methods:
Direct digitization,a ruler is placed on the on
the digitization tablet or on head film itself.The
software will ask the user to digitize 2 or more
points on film or ruler,which gives the comp a
referrence.

In programmes where tablet is not used &
the head film is imaged through a video
camera or a scanner ( in -direct digitization)
Two methods of calibration.

 Grid
 two point system

In first method ( Grid )
A grid is placed on a light box,& a mounted video
camera takes a picture.In the soft ware a preset grid is
already in place to match-up with grid in the light
box.By zooming the lens calibration done.
Second method: (two point system)
Requires identification of two points on the
radiograph.The same two points are identified on the
comp screen using a calibration feature in the
software.

A profile planning
template is created
by integration of
ceph,calibrated to
the facial profile
and displayed.


Simulation of orthodontic decompensation is
created by up righting and advancing the upper
incisor template.
The computer not only allows overlay
&visualization of the pretreatment tracing &
projected dental movement but also measures
these anticipated and planned movements,
which are reflected in a table on the left, which is
shown in the figure.


anticipated and planned movements, which
are reflected in a table


Simulation of orthodontic
decompensation is
created by up righting and
advancing the upper
incisor template.


The soft tissue outline of the upper lip is automatically
adjusted through the algorithmic response
calculations.


The video portion of the software is adjusted to
the prediction outline, simulating a soft-tissue
response to the incisor movement.


Simulation of mandibular advancement is
accomplished by clicking and dragging the
mandibular template forward.
The quantitation table supplies the amount of
advancement required to achieve ideal over jet
and over bite.


Simulation of mandibular
advancement is
accomplished by clicking
and dragging the mandibular
template forward.


Once the mandibular template is
brought forward to ideal over jet & over
bite, the video profile is adjusted to the
cephalometric prediction through the
“auto-treat” or morph function of the
cephalometric software.


See the
soft-tissue
response


The profile is judged to be still moderately
convex, so an advancement genioplasty is
simulated by advancing the template of the chin.
The figure illustrates the cephalometric outline
prediction of a 4 mm anterior movement of chin.


Advancement
genioplasty


This image is auto treated.This movement can be
greatly influenced by patient direction and desire
because there are few functional demands on this
movement


The final prediction image now reflects a
treatment plan that has corrected the
malocclusion and arrived at an esthetically
pleasing profile to both patient and clinician.

Final projected profile outcome with ceph
tracing blinked off

ceph tracing
blinked off


The quantity of all osseous and soft-tissue
changes are also visualized on the monitor.The
ideal face is the goals and target of treatment,
and computer serves as a feedback mechanism
to view the magnitude of the movements
required to achieve the desired outcome and to
decide whether these movements are indeed
attainable.
Overlay of the pre treatment tracing &treatment
prediction tracing with the final video projection

superimposition


Close-up view of profile after orthodontic
treatment,mandibular advancement,&chin
advancement.


After the post- surgical orthodontic therapy is
completed and post operative swelling has
decreased,the clinician is able to compare the
predicted and actual profile results.


VCD

ACTUAL

The final occlusal result is an excellent class I
relation


PRE
VCD

POST

Adolescent prediction
Video cephalometric planning is not
ineffective in the adolescent case, but the
complexities of the facial growth contribute
to inaccuracies in prediction.
In adults it is very accurate because static
nature of dental & soft-tissue relationship.


The factors that contribute to inaccuracies are
Skeletal growth patterns are notoriously
unpredictable
Soft-tissue growth is rarely included in growth
projections.
Co-operation from children towards treatment
is minimal.


VCD Prediction of profile outcome is only as
good as the Cephalometric VTO in the growing
patient.
The comparison of treatment projection & the
final result indicates the current reliability of
adolescent prediction.

Medico-legal issues
The accuracy of video images are effected by

 Honesty of the treatment prediction

- mainly as a communicative tool
- Prediction should be done which can be
achieved



Technical capabilities of clinicians

Close communication is required between surgeons,
orthodontists,and dentists involved in the case and each
member must place faith in other’s capabilities and
follow the plan.

Summary of advantages of vcd
 A higher level of communication
 More precision in this communication
 This communication is more effective & less
time consuming.
Because imaging is more realistic & life-like,the
treatment planning process is facilitated for the
orthodontist by the following

 Improved visualization of the individual
treatment plans.This results in greater precision
in planning a desired outcome.
 Greater participation by patient’s in helping
in the decision making process of their final
result.
 A mutual template is provided for decision
making among patient,orthodontist & oral
surgeon.
 It reduces the guess work in planning.

In a study by sarver,johnston & matuka(j.o.m.f.s
1988) 90% of patient’s reported that the final
result was as good as or better than the
projected image.
This means that


we are very accurate in predicting.



Our surgeon’s are very good at placing the
osteotomies where it is required.


Patient unhappiness may result from
 The planner outlines treatment that is
clinically unattainable.
 The orthodontist or oral surgeon are unable
to “deliver the goods” as outlined or
planned.


Vendors of software


DIGIGRAPH
Dolphin imaging systems,valencia,calif.



PRESCRIPTION PLANNER & PORTRAIT
Rx data design Inc,Ooltwah.



QUICKCEPH IMAGE
Orthodontic processing,coronado,calif



DENTOFACIAL PLANNER
Dento facial software Inc,toronto,canada.



MEASURE
Pacific coast software Inc,pasific palisades, calif

OTP Records
Orthovision Technologies
 ShowCase
Dentofacial Software
 Vistadent
GAC

The cost currently $ 12,000-16,000
( Source: JCO Volume 1995 Oct PETER M. SINCLAIR, DDS, M)


CONCLUSION

It is no more that the doctor is the sole
decision maker .It is the doctor’s legal
and moral responsibility to advice a
patient of risk & benefit considerations
of contemplated treatment and to
present and discuss treatment
alternatives and the risk involved in the
treatment. The vcd might help as a aid
in the process.

Thank you
Leader in continuing dental education


Videocephalometry /certified fixed orthodontic courses by Indian dental academy

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