1. New imaging techniques in orthodontics
Dr Ehsan Tavakoli DDs, OMFR

3. Imaging
2D: PA, Panoramic, Cephalometry,
3D: CT,CBCT,MRI

4. Cone beam CT a new imaging technique in maxillofacial imaging
Synonyms: DVT,CBVI,CBVT,DCT
CBCT is more popular

5. CBCT
Currently, there are more than 47 CBCT systems from 20 different companies available commercially.
There are big variations in the quality of the images and the radiation doses between most of these CBCT systems
Units with reduced radiation doses and less powerful tubes are often associated with poor image quality

6. Various designs:

7. CBCT uses cone x-ray beam instead of fan beam in medical CT
Scan( degrees)
Scan time s

8. Specific Applications
* Implant surgery * Orthodontic treatment planning * Jaw Tumor * Impacted teeth * Periodontal disease * Endodontic

9. Advantages of CBCT Fast scanning time Multiplanar reformation
Inexpensive compared to CT
Compatible with dentistry specified software (implant, orthodontics)
The main advantage for the use of CBCT is that the clinician can get more accurate data from one scan than from the many 2D conventional radiographs traditionally used with less radiation exposure

10. MPR

11. CBCT in orthodontics

12. CBCT in orthodontics supernumerary teeth eruption disturbances
the technique of choice for examining and localizing impacted teeth.
TMJ analysis
Airway study

14. impacted canines and their positional relationship to adjacent teeth

15. Dental development visualization in a mixed dentition

17. Softwares Dolphin (cephalometric analysis)
InVivoDental (3D reconstruction)
3dMD (3D reconstruction)

18. 3dMD software depicting the skeletal and soft tissues

19. Impacted canine

20. Digital study models(cast)
Are introduced as the digital alternative to the traditional stone cast record.
No need for impression taking
They are easier and faster to obtain, to store
Patients benefit from shorter appointment time
provides superior treatment outcome

23. Digital study models(cast)
Root shape, position, and angulations
A gradual transition from the plaster models decade to the digital models is expected to occur in the near future.

24. 3D cephalometry Cephalometric 2D images limitations :
the difficulty in locating landmarks
image distortion
differences in magnifications(L-R),
superimposition of the bilateral craniofacial structures
and measurement errors

25. 3D cephalometry
CBCT produces images that are anatomically real-size 1:1 scale
lack of superimposition of the anatomical structures.
Lack of image distortion
high precision of the linear and angular measurements (Kumar et al., 2007; Moshiri et al., 2007; Kumar et al., 2008).

27. 3D cephalometry
cephalometric planes are defined using three or four landmarks instead of the two landmarks used in 2D cephalometry
allows for the evaluation of the right and the left sides of the skull independently(in facial asymmetry)

28. 3D superimposition
CBCT allows superimposition of images before and after treatment to evaluate the growth and treatment changes
The 2D cepahalograms have been traditionally used to evaluate these growth or treatment changes based on stable anatomical landmarks.
For example, the sella turcica for the cranial base registration
and the mandibular canal for the mandible.
3D images provided easier and more accurate anatomical landmark registration

29. superimposition of the pre- (brown) and post - (blue) treatment skull models of a 12 years old patient treated with rapid maxillary expansion
The use of different colors highlights the changes between the two scans

31. Superimposition: before(red) after(green)

32. 3D facial photographs(stereophotogrammetry)
soft tissue facial analysis
evaluation of the craniofacial growth and development
measurements of the aesthetic facial parameters

33. Image fusion registration of a 3D photograph upon a CBCT
allow evaluation of soft and hard tissue simultaneously
By changing the translucency of the image, the correlation between the facial soft tissues to the skeleton can be determined

34. Image fusion

35. changing the translucency of fused image

36. Thanks for your attention