ameloblastoma of the jaw
Introduction
Introduction to mandibular ameloblastoma Ameloblastoma is the most common odontogenic epithelial-derived tumor of the jaw, accounting for about 80% of this type of tumor. Ameloblastoma is a benign but locally invasive pleomorphic tumor. Its tissue sources include enamel or scalp, epithelial lining of odontogenic cyst, and basal layer of oral mucosal epithelium. According to the World Health Organization and domestic common classification, ameloblastoma can usually be divided into five types, namely, follicular type, plexiform type, granulosa cell type, squamous metaplasia type and basal cell type. basic knowledge The proportion of sickness: 0.003%-0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: molars
Cause
Causes of mandibular ameloblastoma
Ameloblastoma is a central epithelial tumor of the jaw, which is more common in odontogenic tumors. There are different opinions on the tissue origin of ameloblastoma, but most of them are believed to occur from enamel or scalp. The ameloblastoma is macroscopic or cystic, and there are two components in the same tumor. The cystic cavity can contain brown liquid. Under the microscope, the tumor cells are different in size. Bulks or strips, dispersed in the interstitial of connective tissue, according to the World Health Organization and domestic common classification, can usually be divided into five types of ameloblastoma, namely: follicular, plexiform, granulosa cells Type, squamous metaplasia and basal cell type.
Prevention
Prevention of mandibular ameloblastoma
The disease is a congenital disease, early diagnosis and early treatment is the key to the prevention and treatment of this disease. In addition, for postoperative patients, active follow-up should be carried out to prevent recurrence and cause more serious harm.
Complication
Jaw ameloblastoma complications Complications
Maxillary ameloblastoma can affect the maxillary sinus, nasal cavity and eyelids, and there may be corresponding nasal congestion, upward movement of the eyelids, obstruction of the nasolacrimal duct, etc., followed by easy recurrence of the disease. Relatively speaking, the solid or multi-capsule type is relatively simple. The cyst is prone to recurrence, and the curettage and curettage are more likely to recur than radical surgery. Freezing or cauterization can reduce the recurrence rate. After multiple recurrences, it can invade the ankle, sputum, forehead, and even the skull base, intracranial, and more. After the recurrence surgery, it not only affects the face, causes dysfunction, and even life-threatening.
Symptom
Jaw ameloblastoma symptoms Common symptoms Nasal nasolacrimal duct obstruction occlusion relationship disordered tooth displacement slow growth facial deformity bone destruction jaw bulging molar lower lip numbness
1. Jaw bulging and facial deformity: The incidence of mandible is more than that of the maxilla. It occurs in the molar area and the mandibular corner. It grows slowly and has no initial symptoms. The bulging deformation of the jaw is often complained when the patient is on the doctor.
2. Tumors affecting the alveolar bone can cause tooth loosening and displacement.
3. Lower lip numbness discomfort: This symptom occurs when the alveolar nerve or malignant transformation (very low incidence) occurs under tumor compression.
4. Pathological fractures may occur when bone destruction is frequent.
5. Maxillary ameloblastoma can affect the maxillary sinus, nasal cavity and eyelids, and there may be corresponding nasal congestion, upward eyelid movement, and obstruction of the nasolacrimal duct.
Examine
Examination of mandibular ameloblastoma
1, X-ray inspection
X-ray film shows the jaw bulging, irregular multi-atrial cystic light transmission image, the image edge is not smooth, there is a half moon-shaped notch, the size of the room is very different, and the alveolar bone can have obvious "root tip infiltration" "The sign"--the alveolar bone of the root tip is irregularly destroyed and absorbed. The root can be absorbed by serrated or truncated sample. If there is rapid growth and accompanied by pain ulcer, the X-ray shows that the bone space is destroyed. When spotted, it should be suspected of malignant changes.
2, puncture examination
The puncture sac fluid is often brown, sometimes with cholesterol crystals, but without keratinized epithelium.
3, pathological examination
Histopathological examination confirmed the diagnosis.
4, CT examination
High-resolution spiral CT combined with dental software technology, especially multi-slice spiral CT volume data acquisition technology, can not only reproduce two-dimensional curved images reflecting the anatomical features of the jaw and two-dimensional images in any orientation, but also can display the lesions finely. Three-dimensional structure; due to the high density resolution of CT, it can also display the internal structure of the lesion and the density of the contents of the capsule; in addition, the application of different window techniques can also observe the details of bone and soft tissue lesions, all of which are improved. Helps display the characteristics of the mandibular ameloblastoma.
Diagnosis
Diagnosis and diagnosis of mandibular ameloblastoma
diagnosis
1. The jaw is painless and progressively enlarged, which can cause facial deformities, often without special symptoms.
2. The occlusion relationship is disordered, the tooth displacement element is loose or shedding, and occasionally a pathological fracture.
3. The jaw is bulging, the surface is nodular, uneven, sometimes accompanied by a table tennis-like pressure.
4. X-ray film shows the jaw bulging, irregular multi-atrial cystic light transmission image, the image edge is not smooth, there is a half moon-shaped notch, the size of the room is very different, and the teeth that affect the alveolar bone can have obvious "roots" Tip infiltration and stagnation---the alveolar bone of the root tip is irregularly damaged and absorbed, and the root can be absorbed by serrated or truncated sample.
5. If there is rapid growth and accompanied by symptoms such as pain ulcers, X-ray findings of bone space destruction disappear, when spotted, it should be suspected of malignant changes.
6. Puncture cyst fluid is often brown, sometimes cholesterol crystals, but no keratinized epithelium.
7. Histopathological examination confirmed the diagnosis.
Differential diagnosis
Based on the incidence and the need of surgical methods, ameloblastoma mainly needs to be differentiated from odontogenic keratocyst and other non-keratinized cysts. Non-keratinized cysts such as dental cysts, apical cysts, residual cysts and facial fissure cysts, etc. These cysts have certain characteristics from the site of the disease, internal structure and clinical manifestations. It is not difficult to identify with ameloblastoma. Because of the ameloblastoma and odontogenic keratocyst in the pathogenesis, lesion morphology and biology The learning behavior and other aspects have similarities to a certain extent, and the treatment method is different from other non-keratinized cysts. Therefore, the identification of the two is the focus and difficulty of differential diagnosis of cystic lesions of the jaw.
The invasiveness of ameloblastoma is higher than that of keratocyst, which causes the surrounding bone destruction to be larger than that of keratinized cyst and easy to invade surrounding soft tissue. The root resorption caused by ameloblastoma is mostly jagged or truncated, resulting in adjacent teeth. Frequent exfoliation; keratocyst roots are mostly slanted, less causing adjacent teeth to fall off, ameloblastoma is mostly cystic mixed, irregular thick wall, papillary wall or wall nodules can be seen; The cyst is a pure cystic, uniform thin wall. The multi-room ameloblastoma is divided into different sizes. The interatrial septum is usually composed of soft tissue and a small amount of bone components, and is thicker. The size of the keratinized cyst is similar. The septum is slender, intact, and thin. The MR signals of the cystic part of the ameloblastoma are mostly long T1, long T2 signal, and sometimes short T1 signal can be seen in intracapsular hemorrhage; the cystic cyst is rich in keratinized protein and Solid cholesterol crystals, the T2 signal is significantly lower than the ameloblastoma, this sign is considered to be an important feature distinguishing the nature of the two fluids, regardless of CT or MR enhancement examination, the wall of the ameloblast, separation, papillary And wall nodules are obvious Technology; and the partition wall keratocyst no enhancement.
