Orthodontics

Dr. Louw uses OrthoCad™ as part of his treatment planning in an orthodontic treatment case. It is the newest in advanced orthodontics and offers more possibilities than ever before. In partnership with the American company Cadent, all study models are digitalized in 3D format. Patients and parents can see the whole movement of the teeth in 3D and the outcome can be seen even before the treatment has commenced.

The 3D digital study model

This model can be manipulated and moved to be viewed from any possible side. Bracket type and size are selected according to the torque and movement needed on each tooth. All planes are scrutinized. Bracket placement. All brackets are placed on the exact correct position on each tooth to speed up the treatment duration and to give the best (functional and aesthetic) outcome. This outcome can even be influenced by the patient/ parent by selecting the “look” of the outcome beforehand.

Dr. Louw uses Self Ligating brackets by choice. Easy opening and replacement when needed. Low friction. Saves up to 6 months on the treatment duration. Because of being self ligating, the result will be more pleasing and will fit the face better. The combination of indirect bonding and self ligating brackets speeds up the treatment considerably.

Outcome selection
The treatment plan is discussed with each patient and the outcome may also be altered according to the wishes of the patient/ parent.

Central incisor’s clinical crown length is chosen. This causes the bracket (on the picture right) to move to a different position when the outcome is changed.

All angles and planes at a glance.

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Accurate analyses like Bolton, Space, Moyers etc. are performed digitally.

Bonding Brackets are bonded indirectly using trays that are made in the US facility utilizing the 3D digital model. Human error is eliminated.
The result. The treatment duration with OrthoCad is much shorter than any other conventional ortho system. The average treatment leghth is 18 months.

Summary
Orthodontists uses various diagnostic methods to aid in the treatment planning and evaluation of an orthodontic case. Standard methods include study models, panorama x-ray, cephalometric x-ray with analysis and digital photo’s of patient profile and teeth. Dr Louw uses all of these methods digitalized in the treatment planning.

Application in the orthodontic practice
Digital X-ray
Because of the size of digital xray photos, advanced equipment has been developed to digitalize the images and make them available to photo editing software. Two systems are available. The direct system that uses CCD sensors and the less common CMOS sensors.

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Figure. 1. Digital OPG machine for skeletal photo exposure

Frontal, lateral an panoramic photo taking for the fronto-lateral and horizontal planes. High resolutiondigital xrays with pixel quallity of approx. 300 pixels per mm2.

In comparison to the analog x-ray method, this digital device emits 50% less radiation.

Cephalometry

The cephalometric analysis forms a very important role in the orthodontic treatment planning. On this analysis measurements of the profile, the ratio of the upper jaw to the lower jaw, the lip profile, inclination of teeth, jaw angle etc. Is measured. This will determine in which direction teeth will be moved and if any extractions are needed. The facial profile must be improved and not altered too much by the movement of the teeth.

The cephalometric analysis is performed on the lateral skeletal photo (ceph). It can be done by using a transparent piece of paper on top of a printed copy of the ceph or doing it with a software programme such as Kodak Orthotrac.

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Digital tracing done with Kodak software. Fixed landmarks are used on the photo as seen above.

Digital Photography

Digital photography is needed to capture the soft tissue character associated with the x-ray photos. A lot of detail can’t be portrayed by the x-rays and where the digital photos are used for.

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Figure 3. Example of photos taken during treatment planning.

Study Models

The value of study models, whether digital or plaster, lies in the three dimensional properties. The bite can be studied from all angles. Aspects which are not seen on photos. Measurements are performed on these models to determine space shortage/ excess and also discrepancies needed for accurate planning. Plaster study models take up a lot of practice space and this is where the digital model is superior

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Fig. 4. Digital study models.
Fig. 4. b. By moving the mouse, the model can be moved in all directions around it’s own axis.

Coventional impression taking by means of an impression tray and material such as alginate or polyether is being replaced by digital scanning which does not cause gag reflexes and is more accepltable by children. A digital model can then be created immediately by means of CAD/CAM. The ideal bracket placement is selected and even the archwire can be bended by using robotic means (see figure 5)

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Fig. 5. Orthodontic archwires being bended by a robot.

Dr. Louw also does a lot of orthodontic treatment on adults. The OrthoCad method forms a great part of the treatment, but Invisalign and Ormco SimplyFive are also offered. These systems are bracketless and consists of a series of transparent “overlays” which are worn at night to guide the teeth into the desired direction. These methods have limitations and can only be used in basic treatments and minor crowding.

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