Jaw cyst

Introduction to jaw cyst Jaw cyst refers to the appearance of a fluid cystic mass in the jaw, which gradually increases and the jaw expands and destroys. According to the pathogenesis, it can be divided into two types: odontogenic and non-dental, odontogenic. The cyst is evolved from the dental tissue or the tooth; the non-dental cyst can be formed by the epithelium remaining in the jaw during embryonic development, such as a facial fissure cyst, or a blood extravasation caused by injury. Cysts and aneurysmal bone cysts. For the prevention of this disease, early diagnosis and early treatment is the key to the prevention and treatment of this disease. In addition, it should be noted that most of the patients with this disease are related to the dead bone, so the teeth caused by trauma, caries or deformed teeth should be treated as soon as possible. Myelopathy is important for preventing or reducing the occurrence of apical cysts. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of infection: non-infectious Complications: jaw osteomyelitis

Cause of jaw cyst

Disease factor (45%)

1, apical cyst: due to apical granuloma, chronic inflammation, causing residual proliferation of epithelial ganglion in the periodontal ligament. Denaturation and liquefaction occur in the center of the hyperplastic epithelial mass, and the surrounding tissue fluid continuously oozes out, gradually forming a cyst, so it can also be called a periapical cyst.

2, the initial cyst: occurs in the early stage of enamel development, before the formation of enamel and dentin, after the inflammation or damage stimulation, the stencil layer of the oil eliminator is denatured, and liquid seeps out, accumulating And the formation of cysts.

3, containing dental cysts: also known as filter vesicles, occurs in the crown or root formation, liquid leakage between the remnant glaze epithelium and the crown surface to form a dental cyst. Can come from 1 tooth germ (including 1 tooth), also from multiple teeth. Dental cysts are one of the most common odontogenic jaw cysts, accounting for 18%, second only to apical cysts.

4, odontogenic keratocyst: is derived from the original tooth germ or dental plate residue, it is considered to be the initial cyst. The keratocyst has a typical pathological manifestation. The epithelial muscle fiber envelope of the cyst wall is relatively thin, and sometimes contains an ascus (or satellite cyst) or an epithelial island in the fibrous envelope of the capsule wall. The capsule is white or yellow keratin or oily. Accounted for 9.2% of odontogenic jaw cysts.

Congenital factors (35%)

Non-dental cysts are derived from the epithelium remaining during embryonic development and are therefore also referred to as non-dental ectodermal epithelial cysts. Divided into:

1, the ball of the maxillary cyst: occurs between the maxillary incisor and the canine, the teeth are often displaced and displaced. X-ray films show cyst shadows between the roots of the teeth, not at the apex. The teeth have no discoloration and the pulp has vitality.

2, the sac cyst: located in or near the incisor tube (from the residual epithelium of the incisor). The cystic shadow of the enlarged incisor can be seen on the X-ray film.

3, the middle of the cyst: located in the incisor, any part of the sulcus. On the X-ray film, there is a circular cyst shadow between the slits. It can also occur at the midline of the mandible.

4, nasolabial cyst: located in the upper bed and nasal vestibule. May be from the residual epithelium of the nasolacrimal duct. The cyst is on the surface of the bone. There is no damage to the bone on the X-ray film. The presence of cysts can be found on the outside of the oral vestibule.

Jaw cyst prevention

For the prevention of this disease, early diagnosis and early treatment is the key to the prevention and treatment of this disease. In addition, it should be noted that most of the patients with this disease are related to the dead bone, so the teeth caused by trauma, caries or deformed teeth should be treated as soon as possible. Myelopathy is important for preventing or reducing the occurrence of apical cysts.

Jaw cyst complications Complications, jaw osteomyelitis

Some patients with this disease, when the root of the cyst is rooted into the sac, the apical bone of the tooth will be absorbed or tilted or detached. The keratinized cyst is easy to be secondary to infection, and the cortex is absorbed and the edge is unclear, resulting in chronic infection of bone. Thickening and compaction, larger cysts can affect the nasal cavity, maxillary sinus cavity, intraorbital and pterygopalatine structures. In severe patients, the bone gradually expands to the surrounding area, which can form facial deformities. After surgery for patients with cysts, intraoperatively Carelessness can cause other postoperative complications, and the incidence is high, including postoperative infection, recurrence, and spasm formation.

Jaw cyst symptoms Common symptoms Jaw joint pain Facial deformity Jaw cyst Cyst cyst

1. The jaw is progressively painless and swollen, with slow progress and many no symptoms.

2. The larger ones have a table tennis-like pressure.

3. There are often lesions of the teeth (root cysts) or missing teeth.

4. Puncture and extract the grass yellow liquid, the cholesterol crystal can be seen under the microscope, and the cystic fluid of the keratinized cyst (a type of jaw cyst) is milky white keratin or sebum-like substance.

The 5.x light appears as a cystic light-transparent shadow in the jaw bone, and the light-transmissive shadow has a smooth and smooth boundary with a uniform white hardened edge.

Examination of jaw cyst

The following auxiliary examination methods are helpful for the diagnosis of this disease:

1, X-ray film

The cyst of the jaw appears as a circular or oval density reduction zone on the X-ray film. The boundary is clear and the edge is smooth and sharp. It can be single or multiple rooms. With the accumulation of cyst fluid, the cyst has a certain degree of swelling. It can cause displacement of adjacent teeth, a small amount of visible tooth absorption, peripheral bone absorption, and a dense white line (cortical line).

2, computed tomography (CT)

When CT is scanned, the cyst is round or oval, and the edge is smooth. The density of the cyst is related to the contents of the capsule. There are generally two cases: most of them are low density, a few are equal or high density, and the former and cyst contents It is a liquid lipid substance related to cholesterol. The latter is related to the contents of the capsule, which are keratin, hemorrhage and calcification. On CT, the wall of the capsule can be slightly strengthened, and the cystic fluid is not enhanced, and residual roots or teeth can be seen inside. Visible interval, continuity of cortical bone can be interrupted, visible expansion in the surrounding soft tissue.

3, magnetic resonance (Magnetic Resonance Image, MRI)

Oral and maxillofacial MRI has the following characteristics:

(1) There is no radiological hazard to the human body.

(2) Soft tissue resolution is better than CT.

(3) There are no artifacts of ray hardening.

(4) Vascular and soft tissue can be identified without intravenous injection of contrast agent.

(5) Multi-planar imaging.

(6) A three-dimensional image can be obtained.

Diagnosis and differentiation of jaw cyst

diagnosis

1. Increase the painless swelling of the slow jaw, facial deformity, and ping-pong.

2. Puncture extracts the grass yellow liquid, and the odontogenic keratocyst is white keratinized or oily.

3. Patients with odontogenic origin have missing teeth or teeth.

The 4.x light appears as a cystic light-transparent shadow in the jaw bone, and the light-transmissive shadow has a smooth and smooth boundary with a uniform white hardened edge.

5. Histopathological examination confirmed the diagnosis.

Differential diagnosis

1, X-ray film

The cyst of the jaw appears as a circular or oval density reduction zone on the X-ray film. The boundary is clear and the edge is smooth and sharp. It can be single or multiple rooms. With the accumulation of cyst fluid, the cyst has a certain degree of swelling. It can cause displacement of adjacent teeth, a small amount of visible tooth absorption, peripheral bone absorption, and a dense white line (cortical line).

Benign tumors of the jaw are characterized by low-density lesions on the X-ray films, which can be seen as skeletal spaces or interfiber spaces, which are characterized by "soap-like" or "flame-like" changes, sometimes with spotted or spotted calcifications in low density. , mixed density, a few images of hard tissue density visible in the lesion area, there is a clear low-density envelope between the normal bone tissue, the lesion invades the surrounding soft tissue can interrupt the continuity of the cortical bone, benign Non-dental jaw tumors have the same performance as bone tumors in other parts of the body. Primary malignant tumors of the jaw are rare, and their borders are irregular or irregular, and their density can be low density such as primary. Intramaxillary cancer, myeloma; may also be mixed density such as osteosarcoma and chondrosarcoma, calcification of common tumor tissue in the lesion, disruption of cortical bone, and visible radiation-induced periosteal reaction in young patients with malignant bone tumor.

2, computed tomography (CT)

When CT is scanned, the cyst is round or oval, and the edge is smooth. The density of the cyst is related to the contents of the capsule. There are generally two cases: most of them are low density, a few are equal or high density, and the former and cyst contents It is a liquid lipid substance related to cholesterol. The latter is related to the contents of the capsule, which are keratin, hemorrhage and calcification. On CT, the wall of the capsule can be slightly strengthened, and the cystic fluid is not enhanced, and residual roots or teeth can be seen inside. Visible interval, continuity of cortical bone can be interrupted, visible expansion in the surrounding soft tissue.

Benign tumors of the jaw are often characterized by clear, low-density lesions on the CT, often accompanied by an expansive disruption of the buccal and lingual bone plates. In addition, in multi-atrial lesions, osteogenesis is seen, and the malignant tumor of the jaw is on the CT. It is characterized by tumor calcification, cortical bone destruction and soft tissue and intramedullary invasion. At present, CT has become one of the commonly used methods for examining maxillofacial lesions. CT can accurately determine the size, location and invasion of adjacent tissues of maxillofacial tumors. To a degree, studies have shown that CT is more meaningful for the diagnosis of jaw cysts and tumors when the lesion penetrates the cortical bone into adjacent soft tissue.

3, magnetic resonance (Magnetic Resonance Image, MRI)

Oral and maxillofacial MRI has the following characteristics:

(1) There is no radiological hazard to the human body.

(2) Soft tissue resolution is better than CT.

(3) There are no artifacts of ray hardening.

(4) Vascular and soft tissue can be identified without intravenous injection of contrast agent.

(5) Multi-planar imaging.

(6) A three-dimensional image can be obtained.

MRI can show the jaw cyst and tumor invasion of surrounding soft tissue. T2WI images can accurately reflect the boundary between tumor and normal soft tissue. MRI is superior to CT in showing bone marrow changes. Studies have shown that in jaw cysts and tumor invasion of bone marrow At the time, the results on MRI were very consistent with the results of histopathological examination. On the T2-weighted image, the low signal of the normal cortical bone was replaced by the high signal of the tumor, indicating that the tumor invaded the cortical bone, the jaw cyst and the incomplete tumor. The ossification interval and mucosal nodules can be shown on MRI. The reason why MRI is superior to CT in examining the lesions of the mandible is mainly reflected in the simultaneous evaluation of the involvement of cortical bone and bone marrow.

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