A simple and a bit dated presentation on imaging in rothodntics.

1. Dr Jean Marc Retrouvey

2. A new way to look at our
patients

3. Historical perspective
Images and animations from the Stanford University project
Dr Paul Brown

4. Two dimensional radiographic Imaging
for Orthodontic Diagnosis
 Historical perspective
 What is in use today
 2D conventional versus 2D digital
 Digital 2D is now the standard of
care in Orthodontics

5. 1. Cephalostat: Ceph Analysis
 Popularized by Dr Broadbent in the 1930s with
his landmark study “The face of Normal Child”
Angle Orthodontist 1937
 He studied the growth pattern of children with
the help of cephalometric radiographs.
 Still the norm in 2008

6.  Cephalometric analyses
› Used since the 1950
› Well recognized diagnostic tool in Orthodontic
Diagnosis
› Multitude of analyses to analyze the information
provided by the radiograph
› Great to analyze AP projection of the dentition

7.  2D image of a 3D object
 Measure of a plane not a volume
 Misses the z coordinate
 Problems of superimpositions of structure
 Difficulty in picking up the asymmetries
 Dentition is not clearly visible.

9.  Single image
 Rarely used or reported in the literature
 Harder to trace
 Useful to study the transverse dimension
 No real norms have been developed for
this type of radiograph.

10.  Actually, few norms exist to quantify the data
obtained from these 3D imaging systems
 In the future, 3D norms will be established to
analyze the facial structures in 3D
 Systems will become more affordable and
user friendly.

11.  No commercial analyses of the data
provided by 3D imaging is currently available
to the practicing orthodontist (to my
knowledge)
 3D imaging system are getting used in
orthodontic departments in Canada

12. Panoramic radiograph
 Proven method
 The whole dentition and the lower facial
structures are clearly visible
 Fairly affordable system

13.  2D image
 Inaccurate
 Gives only an idea of the problem
 Mainly a screening tool
 Digital system as now are much better
than the standard ones

14. Example: Impacted canines
 Usually diagnosed with the help of a
panoramic radiograph.
 Off angle radiographs are taken to help
position the impacted tooth as accurately as
possible

15. Routine radiograph taken at 9 years of age

16. 11 years old
In this case, the panoramic radiograph was useful in
detecting a potential canine impaction problem

18. Ct Scan usage in Orthodontics
Very limited use in dentistry due to
cost and high radiation dosage

19.  Good 3D visualization of the jaws
 Position of the teeth is clearly visible
 Costly
 High radiation dose for the child
 Offered only in an hospital environment
 Should never be used as routine procedure

20. In the dental discipline, Ct
Scans will be replaced by
Conebeam technology in the
near future

21.  B: 15 year old patient afflicted by multiple
impactions
 Followed by an orthodontist for several years
 Surgery to expose the impacted upper
anterior teeth done a year ago. Surgeon
recomanded to extract anterior teeth
 The orthodontist then refers to the Montreal
Children Hopsital for treatment

25. 3D folderViewerStartInteleViewerCD.exe

26.  We decided to keep the lateral incisors for
now and slowly position to the occlusal plane
 Probable extraction of the upper central
incisors for lack of bone
 Micro implants to expose the lower lateral
incisors and bring these on the arch

28.  Valid procedure for impacted teeth as a real
visualization of the position of the tooth in
relation to the alveolar bone is possible
 Avoid bad surprises with impacted teeth and
root resorption
 Useful for complex eruption sequences

31.  Allows for vision in the 3 planes of space
 Soft tissues as well as hard tissues are
visible
 Tooth anatomy and position are visible
 Great TMJ visualization (hard tissues for
now)
 Asymmetries

32.  You can observe the structures in 3D from
the lateral to the frontal. Multiple images
 The occlusion can be observed in relation to
the osseous structures (advantage over the
study casts)
 Much better visualization of the roots in their
real position (advantage over 2D
radiographs)

33.  Great for complex adult cases
 TMJ cases with a potentially significant
physical component
 “mandatory?” for orthognathic cases
› See Dr Chehade for that.
 In my practice, all orthognathic surgery
cases will go through a Conebeam (machine
is actually being tested on site)

34. When not to use Cone Beam
 Marketing..
 Standard radiographic techniques give
sufficient information.
 Do not irradiate growing kids for the sake of
imaging normal structures
 These tools are there to make our treatment
planning and observations easier and more
precise. Use them appropriately

35.  1. Severely impacted teeth
 2. TMJ visualization
 3.Airway analysis
 4.Complex restorative cases
 5. Orthognathic surgery (to come)

38.  This “new” technology has re-opened my
eyes on TMJ pains and pathologies and
their possible relationship to occlusion
and or malfunction.
 Removing the guessing in severe Cl II
malocclusion

47.  ANB 7
 Retrognathic mandible
 Severe crowding
 Very acceptable esthetics
 14 year old: Camouflage treatment?

48.  TMJ pains are reported (despite the age)
 Mandibular deviation to the right on opening
 These pains are supposed to be transitory
according to several head and neck pain
experts and mainly of psychosomatic origins.
 Anyway…we order imaging of the joints

50. The head of the left condyle is getting smaller. The
cortical bone has disappeared

51.  Great for sleep apnea
patients

55.  Root angulation
 Root torque
 Root length
 Pathologies are clearly visible and seen in
their real position

57.  Patient occlusion is visible in 3D from all
planes of space
 Transverse cuts will be obtained to analyze
torque and interdigitation.
 Relation to the articular condyle is clearly
visible

58.  Conebeam technology should not replace
study casts routinely.
 Study casts (plaster or 3D representation)
remain the standard of care in orthodontics.
 However in some cases, such as
orthognathic surgery and complex
rehabilitation, virtual models may be
indicated

59.  Now we can incorporate STL files from
dental scanners ( intra or extra orals with
files obtained from cone beam CTs.
 We also have a virtual articulator to mimic
rotational motions of the condyles.
 Nothing yet for the translation motions
though

60. Old way to incorporate model
data into a ceph radiograph

62. Diagnostic Wax Up will be replaced by
virtual ones

66.  Huge advantage over any conventional
system
 Better diagnosis
 Better planning (multiple possibilities)
 Superimposition in 3 D
 Possibility to get transfer splints from the
radiograph information with a 3D printer

68.  Planification of case is much better and
multiple options may be explored
 You can transfer the DICOM files to an STL
for a virtual model or order a transfer splint
(using CD-CAM technology)

71.  New user friendlier software for easy
manipulation of images
 We will be able to finish our cases before we
start
 Example: Anatomage or Dolphin 3D
› www.anatomage.com