What Are Mandibular Cysts?

Jaw cyst refers to the appearance of a cystic mass containing liquid in the jaw, which gradually increases and the jaw is swollen and destroyed. According to the cause of the disease, it can be divided into two categories, odontogenic and non-odontogenic. The cysts evolved from dental tissues or teeth; non-dental cysts can develop from the epithelium remaining in the jaw during embryonic development, such as facial fissure cysts, which can also be extravasation caused by injury. Cysts and aneurysmal bone cysts.

Basic Information

English name

cyst of jaw

Visiting department

Oral and Maxillofacial Surgery

Multiple groups

Young adults

Common symptoms

Progressive painless swelling of the jaw

Jaw cyst disease classification

Jaw cysts can be classified according to the origin of the tissue and the location of the disease. They are derived from tooth tissue or the epithelium of the teeth or the remainder of the epithelium. They are called odontogenic jaw cysts. The extravasated cysts and aneurysmal bone cysts caused by the injury are called non-dental jaw cysts.

(I) Dental-derived jaw cyst

Occurs in the jawbone and is associated with dental tissue and teeth. According to their sources, they are divided into the following types:

Apical cyst

It is caused by the apical granuloma and chronic inflammation, which causes the residual proliferation of epithelial ginseng in the periodontal ligament. Degeneration and liquefaction occur in the center of the proliferative epithelium, and the surrounding tissue fluid continuously leaks out, gradually forming cysts, so it can also be called periapical cysts.

2. basal cyst

Occurs in the early stages of enamel development. Before enamel and dentin are formed, after inflammation or injury stimulation, the stellate network layer of the oil generator degenerates, and fluid oozes out, accumulating therein to form cysts.

3. Dental cyst

Follicular cyst, also known as follicular cyst, occurs after the formation of the crown or root of the tooth, the fluid leaks out between the remnant enamel epithelium and the crown surface to form a tooth-containing cyst. Can come from 1 tooth germ (including 1 tooth), but also from multiple teeth.

4. Odontokeratosis cyst

It is derived from the original tooth germ or the remnants of the tooth plate. Some people think that it is the primordial cyst. Keratotic cysts have typical pathological manifestations. The epithelium and fibrous envelope of the cyst wall are thin, and the fibrous envelope of the cyst wall sometimes contains ascus (or satellite sac cavity) or epithelial islands. Inside the capsule are white or yellow keratinous or greasy substances.

(Two) non-dental cysts

It is developed from the residual epithelium during embryonic development, so it is also called non-dental ectodermal epithelial cyst.

Ball maxillary cyst

Occurs between the maxillary incisors and the canines. The teeth are often displaced and displaced. The X-ray film shows that the cyst is shadowed between the roots of the teeth, not at the apex. Teeth have no caries and discoloration, and the pulp has vitality.

2. Nasal cyst

Located in or near the incisor tube (from the residual epithelium of the incisor tube). An enlarged cyst shadow of the incisor canal was seen on the X-ray film.

3. Median cyst

Behind the incisor hole, anywhere in the suture. On the X-ray film, there are circular cyst shadows between the seams. It can also occur at the midline of the lower jaw.

4. Nasal labial cyst

Located on the base of the upper lip and in the vestibule of the nose. It may come from remnants of nasolacrimal duct epithelium. The cyst is on the surface of the bone. There was no destruction of bone on X-ray film. The presence of cysts can pop out of the oral vestibule.

Clinical manifestations of jaw cyst

Jaw cysts occur mostly in young adults and can occur anywhere in the jaw. Apical cysts mostly occur in the upper and lower anterior teeth. Tooth-containing cysts mostly occur in the third mandibular molar, and the maxillary canine area is also a common site. Keratotic cysts mostly occur in the third molar of the lower jaw and the ascending branch of the lower jaw. Tooth-containing cysts grow slowly and there are no conscious symptoms in the initial stage. If the cysts continue to grow and the bone gradually expands to the surrounding area, facial deformities will form. The teeth in the mouth appear loose and tilted.

1. Progressive painless swelling of the jaw bone, progress slowly, and mostly without symptoms.

2. The larger ones had a table tennis-like squishiness.

3. Often there are tooth lesions (root end cysts) or missing teeth.

4. The grass-yellow liquid was extracted by puncture, and cholesterol crystals were seen under the microscope. Keratinous cysts (a type of jaw cyst) have cystic fluid that is milky white keratin or sebaceous.

Jaw cyst examination

1.X-ray plain film

Jaw cysts appear as round or oval-shaped areas of reduced density on plain radiographs with clear boundaries and smooth and sharp edges, which can be single or multiple rooms. With the accumulation of cyst fluid, the cyst has a certain swelling, which can cause displacement of adjacent teeth, and a small number of tooth absorption can be seen. The surrounding bone is resorbed, and the wall of the capsule cavity is a dense white line (cortical line of bone).

2.Computed tomography

During plain CT scans, the cysts were round or oval, with smooth edges. The density of a cyst is related to the contents of the cyst. Generally, there are two cases: most are low density, and few are equal or high density. The former is related to the contents of the cysts being liquid lipids and cholesterol, while the latter is related to the contents of the cysts being keratin, bleeding and calcification. On enhanced CT, the cyst wall may be slightly strengthened, but the cyst fluid is not enhanced. Residual roots or teeth can be seen inside, intervals can be seen, continuity of the bone cortex can be interrupted, and swelling can be seen in the surrounding soft tissue.

3. Pathological examination confirmed the diagnosis.

Differential diagnosis of jaw cyst

1.X-ray film

How should cyst-like shadows be identified as jaw cysts and distinguished from similar lesions. Cysts should be distinguished from central hemangiomas, inflammatory granulomas, and malignant lesions. Dental cysts and fissure cysts themselves.

2. puncture diagnosis

The purpose of puncture is to identify the nature of the cyst and exclude the possibility of other lesions.

3. Biopsy diagnosis

As for biopsy, it is only necessary in rare cases. That is, after X-ray and puncture examination, its nature cannot be determined, and the possibility of inflammatory granulomas, central hemangiomas, or other lesions cannot be ruled out, and final qualitative analysis is required by means of biopsy. Biopsy can determine the nature of the cyst and the presence of other lesions. However, if the puncture is a lot of bright red blood, the biopsy should be very careful to avoid causing uncontrollable bleeding.

Jaw cyst treatment

In the treatment of jaw cysts, in addition to age, the location of the cyst also determines the choice of surgical method. Cysts are located in the maxilla or mandible, anterior or posterior, midline or both sides, and should be treated separately. Different methods should be used for different cyst sizes.

1. Treatment of small cysts

Small cysts caused by apical infections can be treated by:

If it is caused by dead pulp teeth, the root canal can be treated as the root canal, and the cyst can be removed after filling, or it can be filled during the operation, and the apical resection is also performed. Wounds can be sutured, and primary healing is generally available. If it is caused by the residual root, the residual root can be removed, the alveolar fossa can be enlarged and the cyst can be removed or scraped, and the tooth can be sutured to obtain primary healing.

Treatment of fissure cysts in the anterior or midline of the diaphragm, such as incisor canal cysts, epistaxis cysts, or median cysts. Such as a cyst removal, it is easy to penetrate the nasal floor when peeling the capsular membrane, forming an nasal leak. This fistula is difficult to repair and sometimes difficult to repair after multiple surgeries. In this case, it is best not to perform cyst removal, but to perform open resection. That is, the cyst wall that protrudes or does not protrude from the mouth, along with the iliac mucosa on the surface, is not removed. After the meal, the cystic cavity can be washed after eating. Generally, it can be flat for 3 to 6 months after operation. The color of the capsule is similar to that of the iliac mucosa, and there is no need to remove it again. This method is very traumatic and relatively safe, and there are no complications of penetrating the nasal cavity, which is very suitable for the elderly.

2. Treatment of medium cysts

Middle-type cysts in the jaws of the elderly, treatment is more complicated. Most of the elderly lack teeth or have alveolar bone atrophy. If the medium-sized cyst is located in the front of the upper jaw, it may press the piriform foramen into the base of the nose; the posterior may invade the maxillary sinus. If it is located in the lower jaw, the mandible of the elderly becomes narrow due to lack of teeth. A cyst in the body or ascending branch may compress or push the inferior alveolar neural tube, and place the adjacent tooth ectopic or the root tip in the capsule cavity. For one-time cyst removal, the upper jaw may pass through the nasal cavity or maxillary sinus, and the lower jaw may easily damage the inferior alveolar neural tube; if adjacent teeth are damaged, root canal treatment or removal is needed, causing unnecessary pain. These treatments are not suitable for the elderly. Therefore, the treatment of middle-aged bone cysts in the elderly is most safe with window decompression, with less trauma and less pain. Of course, the only drawback is that the healing time is slightly longer, during which time the cystic cavity needs to be flushed after meals. Because the rinsing method is simple, it is not limited by time, and it is safe and comfortable.

Usually the decompression time after opening the window is 6 to 18 months. Stage II surgery is not required for those who have disappeared after decompression. Stage II surgery can be used to reduce the size of the cyst. The purpose of window decompression is not to eradicate the cyst directly, but to shrink the cyst space, restore the shape of the jaw, and protect the shape and function of the jaw to the greatest extent. Some scholars have tried not to perform scraping. In some cases, it has been confirmed that the capsular membrane can be transformed into the oral mucosa after exposing the oral cavity through open drainage.

3. Treatment of large jaw cyst

Patients with large jaw cysts, especially the elderly. Due to the large scope of osteotomy, complicated surgery, prone to facial deformities after surgery, and elderly people who cannot withstand major surgery, it is recommended to use cystic window decompression to reduce the scope of the lesion and restore the jaw shape. Choose the appropriate treatment plan for the specific situation after the operation.