COMPUTERS IN ORTHODONTICS

1. COMPUTERS IN ORTHODONTICS
Dr.Akash Kencha
Dept of Orthodontics and Dentofacial Orthopedics
S.B. Patil institute for Dental Sciences and Research

2. Contents
1. Introduction
2. Use of computers in dental practice
3. Classification of appliance
a)Administrative
b)Clinical
c)miscellaneous
5. Computed Tomography
6. Digigraph
7. VTO
8. Computerised tooth width analysis
8. Cephalometric applications
9. Dento facial planner plus
10. Vistadent image management system
11. Video imaging
12. MRI
13. Invisalign
Application of computers in orthodontics – Contents sem1/sb/09-04

3. INTRODUCTION
When the word "technology" is mentioned, most people think about computers.
Virtually every facet of our lives has some computerized component.
A few years ago, it was considered a specialized component, which has now been
converted to an everyday appliance. The computer is basically an automatic
electronic machine that performs calculations or derives results based on the data
fed into it and the software/ program it is designed for.
A computer is capable of accepting data, performing operations according to
instructions and providing the results of these operations in comparatively shorter
duration of time and with greater accuracy as compared to Manual labor. It is
built to perform routine calculations with speed, reliability and ease.

4. Dentistry, being that branch of medicine which relies
heavily on technology and which embraces new techniques
enhance not only record keeping, but practice management,
patient education and motivation.

5. Uses of computers in dental practice
classification of applications:
1) Administrative applications
 Patient case records
 Recall appointments
 Patient scheduling
 Accounts
 Patient correspondence
 Billing
 Prescription formats
 Post-treatment instructions
 Insurance claims
 Referral information

6. 2) Clinical applications
 Patient photographs-analysis and storage
 Patient radiographs-analysis and storage
 Inter- specialty referral and opinion
 Patient motivation
 Appliance design using CAD CAMs
 Growth predictions
 Visual treatment objectives
 Survey information/epidemiological data
 Presentations
 Continuing dental/ medical education
 Literature reviews

7. 3) Miscellaneous application
 Survey information/epidemiological data
 Presentations
 Continuing dental/ medical education
 Literature reviews
 Entertainment

8.  Orthodontists with their love for technology and
miniaturization have not remained untouched. Computers
are practically used in all the facets of any dental practice
today .Computers have become especially useful to
orthodontists for:
Digital photography
Digital radiography
Digital cephalometrics
Video cephalometrics
3-D imaging
Digital study models

9. Conventional
 Case Paper
 Impression & Diagnostic
Casts
 Radiographs
 Manual Tracing
 Cephalometric Analysis
 Diagnostic Set-up
 Treatment-Preformed
System
 Mid Term Evaluation
Computerised
 Data Sheet
 3D Photography
 RVG, Digital Radiography
 Digitised Tracing
 Advanced software's
 VTO / VTP
 Treatment-Customised
 Continuous Monitoring
Applications of Computers in Clinics

10. Computed Tomography
 Invented by Sir Godfrey Hounsfield
who was awarded a Nobel prize in
1979
 CT is an image display of the
anatomy of a thin slice of the body
developed from multiple x- ray
absorption measurements made
around the body’s periphery.

11. Parts of the Equipment;
1. Scanner ( movable x
ray table + gantry)
2. Computer system
3. A display console

12. Principle;
A x ray source and array of detectors
mounted within the gantry rotate
around the patient during each scan.
Detectors record the attenuation values
of the beam emerging from the
patient
Information from each traverse is a
Profile

13. The tube and detectors
are further angled
and another
traverse is made.
A series of Profiles is
built up.
The computer analyses
the data and an
image is produced.

14. Early scanners translate and rotate
system.
Recently developed scanners stationary
detectors and x ray tube rotates around the
patient
both the
detectors and x ray tube rotate in synchrony

15. Radiation dosage 1.536 rad
for a
single section
1.8432 rad
for
multiple sections
Estimated dose to the centre of the condyl
with CT is 180mR

16.  Useful in determining changes
in bone density
 Primary imaging method when
internal derangement or
arthrosis is suspected – clinical
diagnosis is not always
sufficient.
 Has advantages when planning
treatment or operations on jaws
and TMJ diseases and
deformities.

17. Microcomputed Tomography
Principally the same as CT, except that
the reconstructed cross sections are
confined to a much smaller area.
Significantly reduces radiation dosage.
Used to measure bone connectivity in all
3 dimensions.

18. Cephalometric Applications
DIGIGRAPH
 Introduced by Dolphin imaging systems
 Non-radiographic system
 ‘Digigraph workstation’
 Video images also possible
 VTO
 Reduces time required for records.

19. System design:
The DigiGraph Work Station is
about 5 feet long, 3 feet wide and 7
feet high.
The main cabinet contains the
electronic circuitry, and the patient
sits next to the cabinet in an
adjustable chair similar to those
used with cephalometers.

20. The head holder is suspended from
a beam, supported by a vertical
column attached to the cabinet.
more comfortable than
cephalometer head holders,
allowing the patient to remain in
the holder for several minutes.
Ear rods and forehead and
posterior head pieces are used to
minimize patient movement.
The ear rods can be removed so
that facial and intraoral images can
also be recorded while the patient is
sitting in the adjustable chair.

21. A model board can be inserted into the
head holder, and images of various
views can be recorded .

22. A light box can also be attached to the
head holder for imaging headfilms,
wristfilms, laminagraphic films, and
panoramic x-rays.

23. The video monitor is attached that
can be rotated as the operator
moves.
Images are as sharp as those on a
standard color television.
The images, text, and numerical data
can be displayed, stored, and
modified using either a light pen or a
standard computer keyboard.

24. Any image appearing on the screen can be
reproduced instantaneously with one of three
"hard copy" output devices:
• Sony video imager— makes 5 " x 7 " color
prints in 60 seconds
• Polaroid freeze-frame camera— produces
Polaroid prints in 10 seconds;
• Hewlett Packard Paintjet printer— makes 8 "
x 10 " paper color copies in 4 to 8 minutes.

25. The digitizing handpiece is used to record
cephalometric data while the patient is in the
head holder.
The removable, sterilizable tip of the
handpiece is placed directly on the patient to
record a series of facial and intraoral
landmarks. As each landmark is located, the
handpiece button is depressed and the
location is recorded in three-dimensional
coordinates (x,y,z). Each time the handpiece
button is depressed, an audible sound is picked
up by an array of four microphones on the
beam. The time it takes the sound to reach
each of the microphones determines the
landmark location.

26. Three-dimensional digital
modeling and setup
Aldo Macchi,S Gianpaolo Carrafiello,b Vittorio Cacciafesta,C
and Antonio Norcinic Varese, Italy
 Obtaining accurate images of the craniofacial
region is critical when developing an orthodontic
diagnosis and treatment plan.
 It is a new imaging method that provides
complete 3-dimensional views of the maxilla and
the mandible, and the model setup with individual
anatomic roots. The method uses computed
tomography technology and laser scanning using
computers.
Am J Ortho Dentofacial Orthop, MAY 2005

27. 3D Digital modeling and setup
 3D superimposition of the anatomic teeth, before
treatment [A & B] and after [C & D] the setup to
visualize the amount of teeth movement before and
after treatment [ E ] by making use of 3D setup using
computers.
 By making use of this set up we can analyse a degree of
correction achieved in malocclusion and discrepensies
like fenestrations.
A B
C D E
Am JOrtho Dentofacial Orthop, MAY 2006

28. Airway volume assessment in pt. with mouth
breathing, adenoid hypertrophy, or sleep
apnoea, by application of transfer function to
3D CT scan
Bone rendering with transparent soft
tissues by application of transfer
function ,which render soft tissue
invisible on 3D CT scan.
Visualization of internal anatomic
structures by removal of cranium by
box cut to peek inside a 3D volume by
use of transfer function.
Am JOrtho Dentofacial Orthop, MAY 2005

29. 3D Cone-Beam CT virtual models
 A. Can be Used In case of Surgical patients and those with
developmental anomalies like hemi facial microsomia
where in case ,if the working condyle is missing, it can be
replaced with costocondral graft by proper planning of
surgery using 3D cone beam CT virtual models .
 B. can be used to evaluate significant facial asymmetry
and missing articular fossa.
Am JOrtho Dentofacial Orthop, MAY 2006

30.  Can render bone transparent which allows visualization
of developing permanent teeth & It can also be used to
determine the position of the surgical pins or implants in
bone, that might be impairing tooth eruption .
3D Cone-Beam CT models
Am JOrtho Dentofacial Orthop, MAY 2006

31. Rapid prototyping: A new method of
preparing trays for indirect bonding
Fabio Ciuffolo,a Ettore Epifania,b Gionni Duranti,C
Valentina De Luca,d Daniele Raviglia,d Silvia Rezza,d
Computer-aided technology is used to
design the individualized trays, which are then
produced with a rapid prototyping procedure. The
advantages of application includes time saving
and accurate bracket placement .

32. Clinical application of RPT:
A) Bracket in RPT virtual tray with adhesive paste;
B) RPT placed on tooth;
C) RPT removal;
D)and E) RPT placement on adjacent teeth (full arc
bonding can undertaken);
F) Light-curing.
Design process of virtual
tray:
A) scanned malocclusion
model;
B) virtual bracket
placement;
C) and D)
creation of virtual tray.

33. Computerized tooth width
analysis
 Introduced by Christopher T.C. Ho and Terrence
Freer
 Named as Ho-Freer Graphical analysis of tooth
width Discrepancy (GATWD)
 Base line data obtained from pre treatment
orthodontic casts.

34.  Direct input using digital calipers or manual
input using visual basic 3.0
 Upto 24 tooth width measurements can be
done
 Caliper used is a Mitutoyo 6”/ 150mm , with
tapered beaks
 Connected to a Mitutoyo digimatic mini
processor - IBM compatible
computer

35.  Advantages:
1. Less time consuming
2. Use of digital calipers reduces errors
during transfer of measurements
3. Mathematical calculations done by the
computer
4. Eliminates reference to standard value
tables

36. Classification of Software
 Microsoft Word
 Microsoft Power
point
 Microsoft Access
 Microsoft Excel
 MS DOS
 Microsoft Outlook
 Microsoft Frontpage
 Net Meeting
•SOFTWARE FOR REGULAR USAGE

37.  Adobe Acrobat Reader
 Flash
 Corel draw
 MS Photo editor
 Adobe Photoshop
 Microsoft publisher
 Anti Virus Norton, Sophos…
 3d smax
 Maya
 AutoCAD
 WinZip
 Digicam Software
 Nero Express
 MSC Nastran, Patran
 Ortho cad
ADVANCED USAGE

38. Digitalizing study models using OrthoCAD
 OrthoCAD - It is a digital study model capture,
assessment and storage system.
 It provides a 3D record of the original malocclusion,
any stages during treatment and the outcome of the
treatment.

39. VISTADENT Image management
system
VISTADENT COMPLETE™
ability to modify an image that is stored in the program,
as well as the ability to do Visual Treatment Objective
(VTO).
Images can easily be manipulated to show treatment
objectives by using standard editing features such as cut
and paste or more advanced features like the Smile
Library.

40. Ideal system requirements;
 win 98 operating system or above
 pentium processor II
64 MB RAM
Other attachments:
• digital camera or scanner
• RGB camera
• Printer ( color)
• CD ROM drive

41. Easy to calculate cephalometric analysis.
The Ceph program allows one to trace and
identify your points directly from a
scanned X-RAY.
After points and tracings are entered they can
easily be edited for accuracy purposes. Then
Tracings, Analysis and Measurements can all
be printed on one page with the image.

42. The VTO feature automatically illustrates soft
tissue changes based on measurements for most
orthodontic treatment as well as many
surgeries.

43. Dentofacial Planner Plus is a powerful treatment
visualization software system.
DFP Plus links digitized lateral cephalograms to digital
facial images - move the skeletal and dental components
of the cephalometric tracing - the cephalometric profile
and the facial image are automatically transformed to
represent the predicted facial form.

44. Cephalometrics
DFP Plus contains all of the cephalometric functionality of
Dentofacial Planner,
A digitized radiograph is used as the starting point for a
wide variety of cephalometric analyses and
superimpositions, growth estimation, orthodontic treatment
planning and surgical prediction.
Soft tissue profile changes are automatically computed and
displayed during treatment planning manipulations.

45. Flexible Cephalometric Analysis
Dento Facial Planner and DFP Plus share the unique
functionality of Tools(tm), that provides flexibility in
customizing the work.
Tools - mix and match measurements from several
different analyses into one or more personalized
cephalometric analyses.
They easily add new landmarks, measurements and
graphical reference lines.

46. Image Review:
• simultaneously showing pretreatment and predicted
images:
Other functions;
•Ceph superimposition and narrow review
•Overlay ceph tracing on image
•Semi-transparent image superimposition

47. Video Imaging.
With the integration of computers and
cephalometric technology in the 1970s,
complex statistical analyses of growth
patterns and dentoskeletal relations were
established.
The speed of computerized cephalometric
programs has helped streamline the
laborious manual measurement of patient
cephalograms and the creation of the
visualization treatment objective (VTO).

48. In the VTO of an orthognathic
surgery case, the clinician
classically has used acetate
templates of the teeth and
jaws to predict orthodontic
and surgical movements and
the final profile is determined
by the reaction of the soft
tissue to the hard tissue
movements.

49. Video imaging technology allows the
orthodontist to gather frontal and
profile images and modify them to
project overall esthetic treatment
goals.
The video image is much more
realistic than photograph simulation
and it is much easier for the patient to
comprehend than just the soft tissue
profile of a cephalometric tracing.

50. Tracing Display
Tracings - displayed immediately; include
planes relevant to the selected cephalometric
analysis;
An advantage - is that the nonlinear
distortion associated with radiographs is
eliminated.
- all points are recorded in a direct, one-to-one
manner, allowing precise superimposition of
patient tracings over video images .

51. Visual Treatment Objective
• To move part of the picture, simply touch the
light pen to two points on the screen, at
opposite extremes of the area to be moved.
• The computer draws a box with the two
points at opposite corners.
• Then, by touching the light pen to another
spot on the screen, the boxed image is moved
to that spot .
• Boxes can be moved vertically, horizontally,
or diagonally, or they can be rotated about any
point.

52. The software automatically blends skin
tones and smoothes profile lines so they are
consistent with the surrounding tissue.
"before and after" format.
The light pen can also be used for freehand
drawing over any video image.

53. Coordinating images and cephalogram:
 Digitizing the ceph and then matching the
size of the video image to it
 Digitizing the ceph and then sizing the
ceph to an existing video image (loss of
calibration)
 Gathering the video image of a ceph
through a calibrated video camera and
matching it to an existing video image
 Simultaneous image gathering and ceph.
radiography.

54. Cephalometric Applications
 Downs
• Burstone
• McNamara
• Tweed
• Grummons frontal
• Standard lateral
• Standard frontal
•Ricketts lateral
• Ricketts frontal
• Vari-Simplex
• Holdaway
• Alabama
• Jarabak
• Steiner

55. What is Invisalign®?
Invisalign® is the invisible
way to straighten teeth
without braces.
 uses a series of clear
removable aligners to
straighten teeth without metal
wires or brackets.

56.  co-founded by Zia Chishti and Kelsey Wirth in
1997
 Based in Sunnyvale, California.*
 Align Technology
 the treatment procedure is handled by the
computer technicians in Pakistan - process
takes 3 weeks to a month.
 After approval from the orthodontist,
specifications are transmitted to the
manufacturing plant in Mexico

57. Impressions
are made using
Polyvinyl
Siloxane
Impression and
bite send along
with a detailed
treatment plan.
advanced imaging
technology transforms
plaster models into a
highly accurate 3-D
digital image.
A computerized movie -
called ClinCheck® -
depicting the movement
of teeth from the
beginning to the final
position is created.
After wearing all of
the aligners in the
series,
customized set of
aligners are made from
these models, sent to the
doctor, and given to the
patient. Pt to wear each
aligner for about two
weeks.
From the approved file,
laser scanning to build a
set Invisalign® uses of
actual models that reflect
each stage of the
treatment plan.
Using the Internet, the
doctor reviews the
ClinCheck file - if
necessary, adjustments
to the depicted plan are
made.
Procedure

58.  Patient gets the first aligner 6 weeks after
the 1st visit
 Most treatments require 20 – 60 aligners
 worn for 2 weeks each
 Should be taken off only for eating and
brushing

59. Contraindications;
 patients with severe malocclusions
 All children – growing jaws and erupting
teeth too complicated for the computer to
model

60. Magnetic Resonance Imaging
Principles:
Magnetism is a dynamic
invisible phenomenon
consisting of discrete
fields of forces.
Magnetic fields are caused
by moving electrical
charges or rotating
electric charges.
Images generated from
protons of the
hydrogen nuclei.
Essentially imaging of the
water in the tissue.

61. Equipment;
1. The Gantry ;houses the
patient. Patient is
surrounded by magnetic
coils
2. Operating console ; where
the operator controls the
computer and scanning
procedure
3. Computer room network.

62. The technique is based on the presence of
specific magnetic properties found within
atomic nuclei containing protons and
neutrons.
Inherent property of rotating about their axis
Causes a small magnetic field to be generated
around the electrically charged nuclei.

63. The dipoles exposed within a strong electric
field
Cause Orientation in response to the field
Depending on density and spatial relation
Signal is interpreted and image produced

64. When images are displayed; intense signals
show as white and weak ones as black.
Intermediate as shades of gray.
Cortical bone and teeth with low presence of
hydrogen are poorly imaged and appear
black.

65. The objectives of MRI imaging of the TMJ are;
 Determine relationship between the disc and
Temporal and mandibular components of the TMJ
 Detect inflammation, hematoma and effusion for the
soft tissue components.
 MRI clearly differentiates the soft tissue components .
Short and long echo imaging of the TMJ enables
identification of the positional relationships between
the disc and the condyle.

66.  Indications
 Assessing diseases of the TMJ
 Cleft lip and palate
 Tonsillitis and adenoiditis
 Cysts and infections
 Tumors

67.  Contraindications;
 Patients with cardiac pacemakers.
 Patients with cerebral metallic
aneurysm clips. Slight movement of the
clip could produce bleeding
 Stainless steel and other metals
produce artifacts ; obliterate image
details of the facial area.*

68.  Short comings;
 Inability to identify ligament tears or
perforations
 Dynamics of tissue joint not possible
 Cannot be used in patients suffering
from claustrophobia.

70.  Current principles and techniques in orthodontics- by
Thomas.M.Graber & Robert.L.Vanarsdall.
 Contemporory Orthodontics – by William.R.Proffit
 Gurukeerat Singh, Text Book of Orthodontics, First Edition,
2004 – Jaypee Brothers, New Delhi
 AJODO 2006; August ,volume130 ,no 2 : 257-65
 AJODO 2006: may, volume 129 ,no 5; 605-617
 AJODO 2005volume 128: 157-60
 AJODO 2006 volume 127: 627-637
 AJODO 2005 volume 127 no 5
 World journal of orthodontics December 2006
• OrthoCAD Bracket Placement Solution W. R. Redmond et al,
AJO/DO, May 2004
• Comparison of measurements made on digital and plaster
models M. Santoro et al, AJO/DO July 2003
BIBLIOGRAPHY