Radicular cyst is a cavity formation in the area of the tip of the tooth root, lined from the inside with epithelial tissue and filled with cystic fluid. It is the outcome of chronic periapical inflammation. A patient with a radicular cyst may not make any obvious complaints, they occur when the contents are suppurated or the cyst germinates into the maxillary sinus. The long-term existence of a cyst leads to bone deformation and an increased risk of jaw fracture. For diagnosis, data from objective examination, dental x-ray, electrodontometry and puncture with subsequent cytological examination are used. Treatment of a radicular cyst is performed surgically.
ICD 10
K04.8 Radicular cyst
Meaning
Radicular (or root) cyst is a liquid formation with fibrous walls that forms in the apical zone of the tooth root and restricts the inflammatory focus from healthy periodontal tissues. This is the most common form of cystic diseases of the jaw (jaw cysts) – it is observed in 95% of cases. Cysts of the roots of the teeth of the upper jaw are somewhat more common than the lower one. Men and women are equally susceptible to the development of formations, as a rule, at the age of 20 to 45 years. Radicular cysts can reach more than 5 cm in diameter.
Causes
The main reason for the appearance of a cyst is the presence of an inflammatory process, as a result of which the body forms a connective tissue capsule to isolate the focus of infection. Most often, cysts are formed in patients with a long-existing carious process, pulpitis and periodontitis, or due to illiterate dental intervention. One of the most frequent precursor diseases of a radicular cyst is granulomatous periodontitis, a chronic inflammatory periodontal disease with the formation of specific connective tissue granulomas that gradually grow and turn into cysts.
Often, the cause of infection is a tooth injury, an infectious disease, for example, sore throat, otitis or sinusitis, or a decrease in immunity. The cystic process can also be accompanied by complicated eruption of wisdom teeth, malocclusion.
Pathanatomy
A root cyst is formed from epithelial cells under the influence of an inflammatory process in periodontal tissues. It has thin fibrous walls, is lined from the inside with a multilayer flat epithelium and is filled with a yellow transparent liquid with cholesterol crystals. The formation is formed either directly on the tip of the tooth root – such a cyst is called apical, or it adheres to the lateral surface of the root and is then classified as a lateral periodontal cyst.
Symptoms
For a long time, a cystic lesion can be absolutely asymptomatic or accompanied by signs that are insignificant to the patient, which are most often ignored. With a large cyst, there may be displacement of adjacent teeth and deformation of the alveolar process, and palpation in this area is accompanied by a symptom of “parchment crunch” and a feeling of malleability of the wall under the doctor’s fingers. Facial deformity in patients with a radicular cyst occurs in 36.4% of cases. Due to the growth of the formation, the destruction of bone tissue occurs, and as a result there is a risk of fracture of the jaw.
The symptoms are much more pronounced when the cyst suppurates. This phenomenon can be provoked by a blow to the tooth or another maxillofacial injury, unsuccessful dental intervention, sinusitis, etc. The inflammation starts from the cyst wall, the infected contents turn into pus. There are complaints of pain in the area of the causal tooth and symptoms of intoxication (fever, malaise, chills). An objective examination reveals hyperemia and swelling of the surrounding tissues.
Complications
The lack of proper medical care in this case leads to serious complications, such as fistula, phlegmon of soft tissues and osteomyelitis of the jaw. The infectious process can spread to the paranasal sinuses and the inner ear, causing acute inflammatory diseases of the ENT organs. In dentistry, there is also such a phenomenon as the germination of a cyst into the maxillary sinus. As a result, there is a serious deformation of its walls with atrophy of the spongy substance of the bone and the development of sinusitis in the patient.
Diagnostics
Upon examination, the dentist reveals a darkening of the tooth color (the affected tooth may be under the crown, in which case it is much lighter than the tooth itself) or a running carious process. Probing the root canals is painless and is accompanied by the release of yellowish fluid. Percussion, as a rule, rarely causes any discomfort. To clarify the diagnosis , it is carried out:
- Dental x-ray. Often, a radicular cyst is detected accidentally during the treatment of other teeth. This formation on the radiograph is a round or oval shadow with clear boundaries, located at the tip of the root of the tooth or adjacent to the side wall of the root. The bone structure of the periodontal fissure is destroyed and is not visualized in the image. The roots of the adjacent teeth are displaced. In some cases, it is not possible to identify the cyst even on an X-ray, due to the fact that the root of the causal tooth falls into the visibility zone insufficiently.
- EOM. In order to clarify the diagnosis, the method of electrodontometry is used. The threshold of excitability of the causal tooth is in the range from 100 to 120 µA, which corresponds to pulp necrosis.
- Diagnostic puncture. To find out if the cystic formation is malignant, a puncture is performed with a thick needle. The contents of the non-festering radicular cyst is a yellow liquid with a suspension of cholesterol grains.
- X-ray of PNS. In order to exclude the germination of the formation into the cavity of the paranasal sinuses, it is necessary to additionally perform radiography of the paranasal sinuses. Radiological signs of a cyst are domed protrusion and deformation of the bone floor of the sinus. In doubtful cases, contrast radiography or computed tomography of the maxillary bone is recommended.
Differential diagnosis
Differential diagnosis of radicular cysts is carried out with other cystic formations of the jaw and tumors (ameloblastoma and osteoblastoclastoma). Thus, with a follicular cyst, there is no connection between the disease and the inflammatory process in the causal tooth, and with radiography, the crown of a permanent tooth is visualized in the cyst cavity. Analysis of the dental arch shows the absence of a permanent tooth, or in its place is a baby tooth. Follicular cysts are usually found in childhood and adolescence.
Incisor canal cysts form clearly in the area of the midline of the hard palate behind the upper central incisors. Nasolabial cysts are located under the base of the wing of the nose in the area of the nasolabial beard, and globulomaxillary cysts are located in the space between the lateral incisor and the canine of the upper jaw.
Ameloblastoma is characterized by its location in the area of the angle and body of the lower jaw, while its development is not associated with inflammatory periodontal diseases. During X-ray examination, the tumor has a picture of a single-chamber cyst or polycystic formation with an uncut wisdom tooth inside. To clarify the diagnosis, a puncture and cytological examination of the resulting contents are necessary.
Osteoblastoclastoma differs from a radicular cyst in its cellular structure and less clear boundaries on the X-ray. Getting into the tumor zone, the roots of the teeth, as a rule, are resorbed. When puncturing osteoblastoclastomas, a small amount of brown liquid is obtained without an admixture of cholesterol.
Treatment
Cystotomy
There are two methods of surgical treatment of this disease: cystotomy and cystectomy. During cystotomy, the doctor forms an opening for communicating the cyst cavity with the external environment, thereby reducing the hydrostatic pressure inside the formation as a result of fluid outflow into the oral cavity, nose or paranasal sinus. This intervention is recommended for large formations that destroy the walls of the maxillary sinus, affect the roots of several teeth and do not have radiological signs of an increase in the periodontal gap, and extensive cysts of the lower jaw, thinning its bone tissue.
The operation is performed under local anesthesia according to the following scheme: the surgeon cuts out a semi-oval muco-periosteal flap in the projection of a cystic formation, exposes the bone wall and performs trepanation, after which the cyst cavity is washed and filled with a tampon with iodoform. To prevent relapse during surgery, it is recommended to perform a thorough revision of the tissues and remove necrotic areas. After 7 days, it is necessary to change the tampon and then change the dressing 3-4 times. This intervention is well tolerated by patients, but is accompanied by a long-term existence of a postoperative defect.
Cystectomy
During cystectomy, the cyst is removed entirely by separating its fibrous membrane from adjacent tissues. Next, tamponade of the cavity or convergence of the edges of the mucosa damaged during the operation is performed. This manipulation is recommended for patients with small cysts or large formations in the absence of teeth while maintaining a sufficiently thick layer of bone tissue. In some cases, surgeons consider it appropriate to combine both surgical interventions. In the postoperative period, it is necessary to carefully monitor the condition of the oral cavity, use antiseptic rinsing agents and carefully carry out hygienic procedures. If the temperature rises and there are symptoms of intoxication, it is necessary to consult a dentist-surgeon as soon as possible.
Prognosis and prevention
The absence of pronounced clinical symptoms leads to a late diagnosis of the disease, when, as a rule, its course is complicated by the addition of infection or deformation of the anatomical structures of the oral cavity. In order to diagnose a radicular cyst in a timely manner, it is important to regularly undergo a dental examination. Preventive measures consist in maintaining oral health and high-quality treatment of inflammatory diseases such as caries, pulpitis and periodontitis.
Literature
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