Could MRI be used to help detect cracks in teeth?
Cracked teeth can cause several problems. Cracked teeth can sometimes be treated with a crown, but depending on the severity of the crack, extraction and replacement with a bridge or implant may be the only options.
Magnetic resonance imaging (MRI) technology may be able to help dentists identify those cracks sooner, and intervene before significant damage is done, and/or determine if the tooth is salvable (i.e., not worth crowning), a new study from the University of Minnesota’s School of Dentistry and the Center for Magnetic Resonance Research (CMRR) found.
The study was recently published in DentoMaxillofacial Radiology.
“Dental MRI does not exist in clinical practice and even the wording ‘dental MRI’ sounds strange due to traditional view of MRI as a method totally impractical for imaging of the hard tissues,” said Djaudat Idiyatullin, Ph.D., assistant professor in the CMRR, and first author of the study. “However, in this study we demonstrate that MRI technology can be used not only for imaging a calcified dental tissue, but also, what is more important, to detect microcracks in teeth.”
The proof-of-concept study tested two extracted teeth with known cracks. It was small, but because dental MRI has not been done before, the findings open additional opportunities for research.
“If we’re able to apply this technology to dental care, we may be able to spot cracks in the beginning and prevent patients from tooth loss and pain,” said Don Nixdorf, D.D.S., associate professor in the School of Dentistry.
The team used a specific imaging technique developed by Dr. Idiyatullin and Michael Garwood, Ph.D., professor in the Department of Radiology and the CMRR, along with other CMRR researchers. It’s called SWeep Imaging with Fourier Transformation (SWIFT).
“SWIFT is a unique imaging technique because it allows the MRI machine to capture fast-decaying signal from tissue, which is why regular MRI is not able to image bone and teeth,” said Garwood.
Researchers compared CBCT, SWIFT and Gradient Echo imaging. Only SWIFT detected the microcracks.
They found that SWIFT imaging could detect cracks 20 micrometers wide, which is 10 times narrower than the imaging voxel size. To put that into perspective, red blood cells are about 10 micrometers wide. Through SWIFT MRI imaging, it may be possible to identify a crack the size of just two such blood cells.
Note, MRI machines are not common. Most machines are large and expensive to build and operate, so it is not feasible to introduce MRI machines into dental offices for routine check-ups yet.
Still, more collaborative projects like this one could lead researchers to identify new ways to apply imaging to dentistry, or ways to make MRI imaging more accessible to the dental field. By continuing to study microcracks, dentists can also improve upon current care practices.
“The dental industry lacks data on best practices for the early diagnosis and treatment of cracks and fractures, largely because dentists don’t have access to effective imaging tools,” said Laurence Gaalaas, D.D.S., assistant professor in the School of Dentistry. “Even if we currently cannot apply this work directly to patient care, using the technology could help us better understand cracks in teeth, and to develop more accurate diagnostic criteria.”