CT scan jaw is a method of layer-by-layer X-ray diagnostics that allows for volumetric image reconstruction and detailed assessment of the condition of the patient’s dental system. The scanning area includes the upper and lower jaws, dentition, mandibular canal, TMJ, maxillary sinuses. It is used for planning dental implantation and other operations, diagnosis of developmental abnormalities, injuries, fistulas, tumors, inflammatory diseases of the dental system. The study provides accurate and reliable information about the state of bone tissues, their density, and features of the anatomy of the maxillofacial zone. Contrast computed tomography is performed to study soft tissues and blood supply to the jaw apparatus.
Indications
The procedure is used in traumatology, orthodontics and maxillofacial surgery to diagnose jaw injuries and dental problems. It can be repeatedly carried out in the process of monitoring the effectiveness of conservative therapy, before and after surgery. Each jaw is scanned separately. CT of the mandible allows you to determine its size, the location of the mandibular canal, visualize inflammatory and degenerative changes, tumor processes, fistulas, cavities, complex fractures, dentition injuries, craniofascial anomalies of development, retinated teeth. CT of the lower jaw is used to control implantation, modeling of the jaw and teeth of patients for the manufacture of braces.
In the upper jaw area, scanning makes it possible to state the width and height of the bone, assess the inner surface of the maxillary sinuses, identify the presence of foreign bodies, pathological processes. With the help of computer diagnostics, the implantation of implants, the dynamics of the course of the disease, recovery in the postoperative period, the quality of root canals after the installation of the seal are monitored. CT of the upper jaw is indicated for injuries, developmental abnormalities, visualization of the position of teeth that are unable to erupt independently due to the fact that they are under the bone or gum tissue, cleft palate and pathology of the salivary glands.
Both jaws are scanned for the differentiation of complications of caries, fresh fractures, post-traumatic and congenital deformities, neoplasms, abscess formation. Before plastic surgery, in addition to CT scan jaw, a tomographic examination of the parts of the skeleton is performed, which will serve as a working material for replacing the fragments of the facial skull being removed. As a result, three-dimensional models are obtained, on the basis of which a virtual operation is performed, which greatly facilitates the conduct of a real intervention.
Contraindications
CT scan jaw is contraindicated in pregnant women and children under 14 years of age. The procedure is not performed for mental illnesses accompanied by motor anxiety, since non-compliance with complete immobility leads to a sharp decrease in image quality. If necessary, such studies for vital indications, patients are given shallow anesthesia. The same is done to ordinary patients if they find it difficult to control themselves.
Contraindications to CT scan jaw are the serious condition of the patient, as well as pronounced obesity (due to the limited technical capabilities of the tomograph). Despite the safety of diagnostics, it is not carried out if several studies with X-rays were performed shortly before the procedure (due to exceeding the permissible radiation load). The list of contraindications to contrast CT scan jaw additionally includes intolerance to iodine-containing drugs, severe kidney pathology, diabetes mellitus, multiple myeloma and hyperthyroidism. During lactation, a contrast study is allowed if the patient refrains from feeding after the procedure.
Preparation
Manipulation without contrast does not require preparation. Before the CT scan of the jaw, it is necessary to remove the watch and all metal objects, leave the phone, orthopedic and orthodontic structures, hearing aids outside the office. Contrast CT scan jaw
is performed on an empty stomach, the patient is forbidden to eat 6 hours before the procedure. Women during lactation stop breastfeeding on the eve of the study and resume only two days after its completion. You need to take with you medical documentation compiled based on the results of previous diagnostic procedures, and a doctor’s referral (if available). The patient has the right to undergo a CT scan of the jaw without referral on his own initiative.
Methodology of conducting
Manipulation is carried out using a tomograph, on a mobile table, where the patient lies motionless. The design features of the device allow you to use scanning to examine a fairly narrow area (from 040 x 50 mm to 080 x 80 mm). To expand the possibilities of diagnostic search in CT scan jaw, the technique of connecting several sections is used. The study lasts from 15 to 25 seconds, the exposure is 3-12 seconds, the radiation dose ranges from 350 to 1600 mGr * cm2.
When performing a CT scan of the jaw, the tomograph table automatically moves through the radial tunnel, into the walls of which sensors are mounted, layer by layer recording the results and transmitting them to the monitor. The image processing program allows you to take pictures in 3 projections: sagittal, coronary and axial. To improve orientation in the layers, an expanded curve can additionally be built. It is possible to estimate the density of the jaw tissue on the Hounsfield scale. The patient is isolated in a room shielded from X-rays during a CT scan jaw. The doctor (laboratory assistant) observes the course of manipulation from the next office, communicating with the patient through the microphone of the tomograph. Diagnosis does not cause unpleasant sensations.
The procedure with contrast is carried out for 15 minutes. Before contrast CT scan jaw, a skin test is performed to exclude intolerance to the drugs used. If the result is negative, an iodine-containing substance is injected into the patient’s vein, they wait a few minutes until the drug is evenly distributed and accumulates in the examined tissues, then a CT scan of the jaw is performed. At the same time, the radiation load does not increase. Teeth are not examined with contrast, since the main purpose of contrast examination is the tumor process, and it does not happen in the dentition.
Interpretation of results
The transcript of the results obtained is carried out by a doctor. An hour after the manipulation, the patient is given pictures and a conclusion on his hands, where the course of the scan is described in detail. Deciphering the CT scan jaw, the diagnostician pays attention to the intensity of darkening, describes the presence of organic changes and the structure of intraoral tissues. The absence of pathological disorders in CT scan jaw is interpreted as the norm. In case of detection of any pathology, a consultation of specialized specialists, hospitalization or planned therapy is prescribed. CT scan jaw has indisputable advantages over other radiation techniques. It is more accurate and informative, provides a set of scans, on the basis of which a 3D image is built. The dose of X-ray radiation during CT scan jaw is less than with conventional radiography.
