"Off to the CT scan!"
...you hear from the doctor, and you head towards the office behind the massive door. Just a few moments later, the doctor receives complete information about the condition of your teeth (and more). What can a 3D scan reveal about your health? How safe is diagnostic imaging with computed tomography? Who is it recommended for, and who should avoid it? Let’s dive into these questions in this article.
Cone Beam Computed Tomography (CBCT), or 3D dental imaging (sometimes called 3D CT or simply computed tomography), is a method widely used for diagnosing dental issues and ENT (ear, nose, and throat) conditions.
CBCT is most often ordered during the initial consultation. It allows the doctor to get a comprehensive view of the teeth, the maxillofacial area, and adjacent ENT organs, even if the patient has no obvious complaints and came for a routine check-up. However, if the patient complains of pain or discomfort, the CT scan becomes an indispensable tool.
Why CBCT?
Why use CBCT when you could just take a single tooth X-ray or a panoramic X-ray (showing all the teeth on both jaws)? The issue is that these images do not reveal internal structures, assess the number of root canals, or examine the roots' specifics.
If a dentist determines that tooth treatment is necessary, for example, due to deep decay or nerve damage, it's crucial to understand the layout of the root canals to properly and completely fill them. CBCT helps detect micro-cracks, assess the thickness of the tooth wall, and decide whether pulp removal, filling, or a ceramic inlay is needed.
Before placing a crown, an orthodontist needs to ensure that the root canals have been adequately filled to prevent inflammation under the crown. If implants or prosthetics are required, CBCT helps evaluate the bone condition and choose the appropriate treatment method.
Typically, CBCT is performed during the initial consultation, and then, if necessary, panoramic X-rays are used to monitor the placement of implants.
What else does the 3D scanner see?
CBCT allows for detailed examination of ENT organs, such as the sinuses and inner ear, to detect inflammation or fluid accumulation. When placing implants in the upper jaw, it’s essential to check the sinus cavities. If pathology is found there, it needs to be treated by an ENT specialist first.
In children, CBCT helps diagnose adenoids, which are often associated with malocclusion. Breathing issues through the nose can affect the development of the facial skeleton and bite, which may require dental intervention.
If a patient snores at night, it may be related to a deviated septum, which can also be seen on the CT scan. In such cases, the dentist will refer the patient to an ENT specialist to correct the issue and improve nasal breathing.
CBCT also helps rule out bone pathologies of the skull. If a patient complains of vague pain, CBCT can pinpoint the problem's source and refer them to the appropriate specialist.
A Painless Procedure
The CBCT procedure takes just 14 seconds and requires no special preparation. The patient needs to remove any metal objects that could affect the image quality. The patient assumes the correct position, and the machine rotates around the head, creating a 3D image.
The procedure is completely painless and does not trigger a gag reflex. Even young children tolerate it well.
Age Is Not a Barrier
CBCT can be performed from a very young age, as long as the child can remain still for 14 seconds. The diagnostic is used if root canal treatment or crown placement is needed. Losing a tooth at a young age can delay the development of permanent teeth, so timely diagnosis and treatment are crucial.
The procedure for children is the same as for adults. If a child is scared, a parent can be present in the room to provide support.
CBCT Limitations
While CBCT allows for the examination of bone structures, it is not suitable for detailed analysis of soft tissues. For this, spiral computed tomography (CT) is used, which detects the presence of fluid, cysts, or polyps. However, CBCT is sometimes used to clarify diagnoses, especially if spiral CT produces artifacts due to metal structures in the mouth.
Radiation Exposure and Safety
We are exposed to background radiation daily from food, water, and our environment. For example, eating a banana gives us 0.0001 microsieverts of radiation. A flight on an airplane equals 80 microsieverts, roughly equivalent to four CT scans for a child.
Background radiation varies by region, but the allowable dose is 1000 microsieverts per year. With CBCT, the radiation dose is controlled based on the patient: adults receive up to 26 microsieverts, while children receive 21 microsieverts. The permissible dose for medical indications can reach up to 500,000 microsieverts per year.
Equipment quality and radiation doses are monitored annually to meet standards.
Who Should Avoid CBCT?
Any X-ray procedure has contraindications. Primarily, CT diagnostics are contraindicated for women in the first and second trimesters of pregnancy, as this is when the fetus's organs and systems are developing. In the third trimester, the procedure is only possible for strict indications and with the approval of an obstetrician-gynecologist.
If dental treatment is needed during pregnancy, it is carried out temporarily and to a minimal extent to avoid risks to the fetus.
CT scans are also contraindicated for patients with tumors and those who have undergone chemotherapy. They are advised to wait 6-8 months before starting dental treatment.
CBCT is Not Contraindicated for Nursing Mothers
X-ray procedures do not affect milk quality and are safe for the baby. There is no need to pump milk after the procedure; feeding can continue without stress for the mother and the baby.
Just a few seconds—and the doctor knows everything about your teeth (and more).
