CT scan safe, effective to detect dental problems

July 13, 2014 9:38 pm

by GEORGE NAVA TRUE II

Radiation is like a double-edged sword. With the right dose, it can treat disease and help doctors diagnose patients. In the wrong hands and with a bigger dose, it can kill.

The pioneering research of Marie Curie, the first woman to win a Nobel Prize, proved that radiation could be both friend and foe. Curie’s work on radioactivity paved the way for a better understanding of this powerful force and helped shaped the modern world.

However, the damaging effects of radiation were not known at that time and Curie died on July 4, 1934 from long-term radiation exposure.

Her tragic death was not in vain though. Curie’s passing led to the development of safety measures and contributed to our vast knowledge of radiation today.

Indeed, Curie is long gone but her legacy lives on in modern medical equipment that utilizes radiation for the benefit of patients. One important use is in the field of dentistry where cone beam computerized tomography or CBCT is becoming a popular tool among local practitioners.

Many of us are familiar with the conventional computerized tomography (CT) scan – also known as computed axial tomography (CAT) scan – where the patient enters a huge chamber that makes strange (some say creepy) noises. This device uses rotating x-ray equipment and a digital computer to see inside the body. With this tool, one can view clear images of bones, tissues, muscles, and blood vessels.

The machine gives cross-sectional images of the body that are used mainly in diagnosing different types of cancers. A CT scan not only confirms the presence of cancer in the body but it can tell the precise location and size of the tumor. CT scans also help determine whether the cancer has spread to other parts of the body. This information can help the doctor plan radiation treatments and surgeries.

Since it can visualize almost all parts of the body, a CT scan can also tell whether a patient has internal injuries. This provides doctors with vital information that cannot be obtained from ordinary x-rays.

“Thanks to its ability to provide clear images of bone, muscle and blood vessels, CT imaging is a valuable tool for the diagnosis and treatment of musculoskeletal disorders and injuries. It is often used to measure bone mineral density and to detect injuries to internal organs. CT imaging is even used for the diagnosis and treatment of certain vascular diseases that, undetected and untreated, have the potential to cause renal failure, stroke or death,” according to Conebeam.com

A dental CT scan or CBCT is a smaller version of the regular CT scanner. Think of it as the son or daughter of Big Daddy CT scan. This compact instrument delivers a cone-shaped x-ray beam and works faster and with less radiation. In spite of its small size, this David can stand up to any Goliath in terms of patient benefits.

“The CT scan, often used in medical practices to assist in the treatment of cancer and heart disease, is increasingly becoming an important technology used in dental practices to help dentists conduct complicated oral surgeries and procedures. The dental CT scan is a three-dimensional (3D) rendering that offers a detailed image of the area scanned inside the mouth. Dentists using CT scan are able to take images from a variety of angles, and due to the high-level of detail are able to detect such details as nerve endings and sinus cavities before performing surgery, thereby mitigating potential complications during and after the procedure. Specifically, the dental CT scan is used to render effective, but safe, care to the dental patient,” said Wisegeek.com

Ask Dr. Kenneth Lester Lim, an oral implantologist who holds office at Suite 202 of the Jollibee Center Building, San Miguel Avenue, Ortigas Center, Pasig City, and he will tell you about the amazing power of the dental CT scan. This non-invasive imaging technique was first introduced in Europe in 1996 and uses a rotating scanner that takes pictures of the patient’s teeth. But these are not ordinary snapshots mind you. The 3D images can be viewed with special software and tells the dentist exactly what’s wrong with the patient.

“If you go to a hospital and take a conventional CT scan, your whole body enters a small chamber that produces funny noises and this can be uncomfortable for people who are claustrophobic. The good thing about a dental CT scan is that it is confined to the upper and lower jaw,” explained Lim, a professor at National University in Manila.

“We don’t expose our bodies to unnecessary radiation. The dentist gets everything he needs in one sitting. It’s safe because there is less radiation. It’s convenient because it can be done with the patient either sitting or standing,” he added.

For many dentists, this small yet indispensable tool is important in diagnosis and treatment planning, especially in the fields of oral implantology or implant dentistry, orthodontics (improper bites) and endodontics (root canal therapy).

In the case of dental implants (artificial teeth anchored to the jaw) that have helped many toothless people eat and speak normally, a dental CT scan can accurately tell the dentist whether the patient has enough bone to accommodate these prostheses.

With traditional panoramic x-rays, dentists get only a limited view of the patient’s problem. This two-dimensional (2D) image shows the height and shape of the jaw but bone width and density remain a mystery. This makes it hard for the dentist to determine whether the patient is an ideal candidate for dental implants.

“Dental CT scans give clear 3D images and help the dentist see the patient from all angles – the front, back, inside, sideways, the left and the right. In 2D, it’s like looking at the mirror. You see yourself but you don’t see what’s behind you. If you have a wound at the back, you won’t see it. This is the biggest advantage of a dental CT scan – you see everything,” Lim said.

“All defects could be seen and measured. Before the dentist conducts surgery, he already knows what to do and he can prepare for it. He won’t be surprised anymore since he knows everything about the patient. He knows exactly what’s happening. This eliminates frustrating delays and costly mistakes,” he explained.

While a dental CT scan has less radiation than conventional x-rays and the big CT scanners found in hospitals, concerns have been raised about the side effects of multiple bursts of radiation that the former deliver. To avoid problems, Lim said a CT scan should be done by a professional who is familiar with the technique.

Another drawback is the price. A dental CT scan can cost anywhere from P8,000 – P10,000 which is way beyond the reach of many Filipinos. Still, this covers the entire mouth and takes the guesswork out of dentistry.

In short, the patient no longer has to take repeated x-rays and expose himself to unnecessary radiation since a single CT scan will show everything. This makes life easier for the dentist who already knows what the problem is and can deal with it effectively. For many patients, that is a small price to pay for peace of mind.

“Not all dentists have CT scanners but this will hopefully become more common in the next five to 10 years. Some dentists send patients to the hospital for a CT scan but a dental CT scan is cheaper in the long run since you get the whole picture,” Lim concluded.