Dentists and orthodontists could often benefit from precise views of their patient's skull, but most are limited to X-rays. Imaging Sciences International is making it practical for dentists to put a computed tomography system in their office so they can record 3D images.
ISI's Cone Beam 3D Dental Imaging System, called i-CAT, provides high resolution, volumetric images that display 3D analysis of bone structure and tooth orientation. That can be important for orthodontists and for dentists performing implants or other complex procedures.
These dental clinicians can examine precise cross-sectional slices of any location in the maxilla or mandible, seeing the dimensions and locations of critical anatomy. "Three-dimensional, volumetric imaging provides revolutionary information for implant planning and orthodontic treatment and care," says Edward Marandola, general manager at ISI, headquartered in Hatfield, PA.
The ability to perform these scans in the office will make it far simpler for dentists to have access to images that have required costly hospital visits for patients in the past. "Medical imaging advanced by leaps and bounds in the '80s and '90s, but dentists still have to send patients to the hospital if they want a scan of their skull," says Arun Singh, vice president & director of advanced technology at ISI.
There are two key parameters for acceptance in dental offices. "There are significant cost and space constraints in a dental office," Singh says.
To meet the size constraints, the i-CAT requires less than 60 square feet of floor space, so it can fit in a small room. A key element for shrinking the hardware is an amorphous silicon flat panel image sensor that is commonly used in oncology. The image capture screen measures 20×25 cm.
X-rays sent through the patient's skull are captured by the flat panel, then sent to a PC. "We're doing the same thing that happens with X-ray film, but we're capturing the image electronically with the flat panel," Singh says. Another benefit is that the system has less radiation to patients than conventional fan beam systems.
On the financial side, it's in line with other high-end dental equipment. The basic system costs $155,000. That's half the cost of medical CT units, the company says. A $25,000 option provides an extended field of view, imaging the entire skull. That option will be used primarily by orthodontists, Singh predicts.
One factor behind the falling cost is that the company can now leverage PC pricing. "PC technology has advanced dramatically, data capture is a lot better and storage capacity has grown substantially," Singh says.
There are many technical aspects beyond these market considerations. A short processing time is a key factor for owners and operators as well as for the patients who must sit still during the imaging. The typical scan time for the system is just 20 seconds, according to Singh. After that quick scan, there's an exact replica of the person's head.
Though that quick imaging step is accomplished while the unit revolves around the patient, it requires very precise movement. "We designed a compact mechanical system with the flat panel, making sure that its 360-degree rotation around the head is precise. We can't even afford a quarter mm of wobble," Singh says. Any unwanted movement would result in inaccurate imaging, he adds.
It takes about two minutes to produce the primary reconstruction of the 3D images. Secondary reconstruction of any desired view can be displayed in real-time.
Looking at speed from the dentist's and patient's point of view, the system provides significant benefits. By having the scanner in the office, dentists can insert finished dental implants in one visit instead of the many months that it now requires. Singh notes that patients sit while the image is being taken, which can be less intimidating than scanning systems that require them to lie down.