Panoramic dental x-ray is the two-dimensional (2D) medical imaging technique most commonly used by dentists and oral surgeons for general screening of oral problems.
In the diagnosis of oral diseases, the dentist uses intraoral or extraoral medical imaging techniques depending on the area to be visualised in detail. Intraoral X-rays include periapical, occlusal and bitewing, while extraoral X-rays include panoramic, cephalometric and cone beam computed tomography.
Panoramic dental X-rays allow the entire mouth to be visualised in a single image. It is preferred for patients who have a gag reflex against intraoral X-rays.
The radiological imaging method performed with X-ray beam contains ionising radiation, albeit in low doses. According to risk assessments, there is no harm in its application in adults and children over the age of 5, but if there is a possibility of being pregnant, the treatment should be postponed by informing the dentist. Since the exposure time is approximately 20 seconds, it is not suitable for children under the age of 5 and people with disabilities.
X-ray preparation consists of several stages. First of all, jewellery, glasses, metal objects, prostheses are removed. X-rays with an implanted tooth do not have any disadvantages. A double-sided radiation protective lead vest is worn to prevent other parts of the body from being affected by radiation.
The application is usually performed standing up, but the device can also be adapted for patients using a wheelchair. The patient’s head, forehead and chin are centred with supports. For proper alignment of the teeth, a bite bar with a disposable plastic sheath is placed in the mouth.
In order to obtain a clear and understandable image, the patient stands still without moving. The X-ray technician starts the exposure by directing the X-ray beam to the relevant area. The X-ray device draws a semicircle by moving between the jaw joints. After the exposure is completed, the X-ray device creates the digital image. The dentist facilitates the diagnosis by making contrast and brightness adjustments in the digital image.
The two-dimensional image taken with a panoramic dental X-ray is formed by superimposing different anatomical structures consisting of upper and lower teeth, nerves, sinuses and jaw bones. Abnormalities in these structures are diagnosed. The curved structure of the jaw is shown in the two-dimensional plane in a flat-opened form. Soft tissue and air cavity shadows may obscure the hard tissues.
Through the X-ray image, diagnoses such as tissue loss in the jaw bone as a result of advanced periodontal diseases, cysts and tumours in the jaw bones, oral and jaw cancer, tooth decay, gum infections, wisdom and other impacted teeth, jaw joint disorders and sinusitis are made.
While hard tissue diagnoses are made by radiographic methods, soft tissue diagnoses are made by magnetic resonance imaging (MR). Today, studies are continuing due to technological developments in order to visualise hard and soft tissues at the same time.