Your dentist may recommend a dental CT (computerised tomography) to check what is going on in your mouth — and you keep wondering, “Why a CT? Why not an X-ray?
Here we explain why this may be required and how they work
- Dental CTs are a revolutionary tool in dentistry. They form 3D images of the oral structures and reproduce the tiniest details precisely.
- Dental CTs are safe, quick, and patient-friendly and can be integrated into dental setups. Dentists use them to diagnose, treat, monitor, and for future referrals.
- Dental CTs are not routine procedures. Your dentist might recommend one if an X-ray is not enough to provide in-depth insight into what’s going on inside your mouth.
What is a dental CT?
A CT is a short form for computed tomography. You probably have heard of a CT scan for other areas of the body, such as the abdomen, knee or brain. Similarly, there are CTs specific for oral health. Dental CTs are three-dimensional imaging techniques, unlike conventional dental x-rays which only provide two-dimensional images of teeth and oral structures.
First developed in the late 1980s, dental CTs are now a part of standard setups across dental clinics and hospitals. As a result, they are used in day-to-day treatments, especially when dealing with complex cases or advanced dental technologies. The important structures that a dental CT covers include teeth, roots, soft tissues (tongue), upper and lower jaw bones, temporomandibular joints, maxillary sinus, nerves in and around the oral cavity, and parts of the pharynx and airway.
Conditions that may require a dental CT
Here are some conditions where you may need a dental CT.
- Failed root canal therapy. Extra canals that go undetected are a major cause of a failed RCT. Dental X-rays can show only a single angle of the teeth and are unable to detect overlapped or narrow canals. That’s when dental CTs are very helpful. They can detect overlapped, narrow, and missed canals raising re-RCT success rates to over 90%.
- Jaw joint assessments. Dental CTs are one of the best tools for checking the joint’s position, alignmzent, and any potential abnormalities. Moreover, dentists can look at the bones, cartilage and muscles around the joint to get a complete picture of what’s happening. If you’re dealing with jaw pain, swelling, or jaw locks, a dental CT scan can be extremely helpful.
- Evaluating impacted teeth. Impacted teeth, especially wisdom teeth, can be difficult to evaluate in routine X-rays. A dental CT aids dentists in determining the location and angulation of wisdom teeth and helps plan an extraction accordingly.
- Detecting trauma. Dental CTs give doctors detailed images making it much easier to spot fractures, assess the damage, and plan surgeries. As oral and facial fractures often occur together, CTs are helpful because they provide a detailed, comprehensive template of the surrounding facial structures.`
- Implant positions. The success of dental implants relies heavily on a thorough pre-operative evaluation of the area, including the nearby structures and how the implants will be positioned in the bone. In addition, your dentist must navigate around vital nerves and arteries during the placement. This is where dental CT scans come in. These scans provide high-resolution images with great clarity that showcase the bone structure, texture and quality. These scans also serve as a powerful tool for determining whether you are a suitable candidate for dental implants in the first place.`
- The extent of cysts and tumours. Dental CT scans provide exact measurements, location, and extent of growth for dental cysts and tumours. Furthermore, CT scans’ 3D pictures provide crucial information about a cyst’s shape, boundaries and possible encroachment on adjacent structures.
- Orthodontic treatment assessment. Planning is a key step in teeth straightening. CT scans help devise personalised treatment plans, determine the need for tooth extractions and evaluate whether braces or aligners suit the case.
Your dental CT is like a 3D virtual model of your mouth. It helps dentists to diagnose, detect, treat, and monitor progress. And the best part is it’s digital. It can be stored, retrieved, and transferred across systems. So, if you are moving or on vacation, visiting a new dentist, or continuing your therapy after a time gap, your dentist can always look back at a previous CT or forward the same to your new dentist.
How dental CT scanners work – the tech!
- These images are stacked (like a stack of coins) and processed to produce 3D images of your mouth. All this happens in less than a minute before you can see them on the monitor.
- These X-rays are captured onto a detector opposite the source. As the scanner spins, it takes snapshots from various angles. These high-resolution images capture the tiniest of details.
- It releases a narrow X-ray beam — in the form of a cone or a fan. These X-rays are invisible and can penetrate teeth and bones.
- Dental CT scanners have a large circular C-arm that spins around your head, similar to a spinning top.
While all of this may sound simple, millions of technical instruments within the scanners are working in synchrony to get a perfect scan.
