Mandibular cancer is a malignant neoplasm characterized by an infiltrative type of growth, early metastasis. Patients indicate the appearance of acute paroxysmal pain radiating along the mandibular nerve, paresthesia of the lower lip and mental region, the presence of pathological mobility of intact teeth. Diagnosis of mandibular cancer includes clinical, radiological and cytological studies. Treatment of mandibular cancer consists of pre- and postoperative telegammotherapy, radical resection of the affected part of the bone. When metastases are detected, lymphadenectomy is performed.
C41.1 Malignant neoplasm of bones and articular cartilage of other and unspecified localizations. The lower jaw.
Mandibular cancer is a primary or secondary (metastatic) malignant tumor affecting the mandibular bone. Cancer of the lower jaw is diagnosed less often than the upper one. For one case of mandibular cancer, there is one case of sarcoma of the same localization. The primary tumor process is detected mainly in men after 40-45 years. More often, a malignant neoplasm is localized in the molar area. Metastatic cancer of the lower jaw occurs mainly in women due to metastasis of tumors of the breast, stomach. Histogenetically, mandibular cancer in the vast majority of cases is squamous keratinizing.
The main causes of mandibular cancer are obligate and facultative precancerous mucosa lining the alveolar process. Malignant lesion of bone tissue develops as a result of malignancy of papillomatosis, erosive or verrucous form of leukoplakia. With a long-existing decubital ulcer of the mucous membrane, which appeared as a result of chronic trauma by the sharp edges of destroyed teeth, the risks of the transition of the inflammatory process into a tumor process are also high.
Cancer of the lower jaw can also occur as a result of the germination of a malignant neoplasm into the bone from adjacent anatomical areas. Tumor cells can spread to the bone tissue from the bottom of the oral cavity, the retromolar area. In rare cases, patients with primary cancer of the lower jaw, developing directly into the bone from the remnants of the dental rudiment or epithelial cells of the shell of an odontogenic cyst, turn to the department of dentistry.
According to the prevalence of the tumor , the following stages of mandibular cancer are distinguished:
- T1 – malignant neoplasm is localized within one anatomical area.
- T2 – mandibular cancer spreads to two adjacent areas.
- T3 – the tumor extends beyond two anatomical regions.
- T4 – the whole organ is involved in the tumor process.
In cancer patients, cancer can affect the anterior part of the mandibular bone (in the projection of the lower incisors), lateral areas (not including the angular zone), as well as branches of the mandible.
The first signs of mandibular cancer are acute shooting pains. On the mucous membrane along the transitional fold, an ulcerative surface with a gray dense bottom and torn, pitted, turned-out edges is found. With the infiltrative spread of the tumor deep into the underlying tissues, as a result of compression and gradual destruction of the mandibular nerve, numbness of the lip and chin occurs on the side of the lesion. In case of violation of the integrity of the cortical plate, the spongy substance, intact teeth begin to loosen.
After removal of the movable tooth, the tumor tissue grows rapidly, filling the hole. Epithelialization processes are not observed at the same time. From the distal parts of the alveolar process, cancer of the lower jaw spreads to the masticatory muscles, pharynx, palate. Patients indicate a painful limited opening of the mouth. There are pronounced pains when chewing, swallowing.
When mandibular cancer germinates into adjacent soft tissues, facial asymmetry appears, the alveolar process is deformed. As a result of osteolysis, even from the impact of small forces that do not exceed physiological ones, a pathological fracture of the lower jaw may occur. Mandibular cancer is characterized by early metastasis to the submandibular and cervical lymph nodes.
Diagnosis of mandibular cancer includes the collection of complaints, anamnesis of the disease, physical examination, radiography. The results of cytological examination are decisive in making a diagnosis.
- Objective data. In secondary cancer of the mandible, a crater-shaped ulcerative surface with a dense bottom covered with a gray plaque and torn, pitted infiltrated edges is revealed on the mucous membrane of the alveolar process in the transition area of the stationary mucosa to the mobile one. On palpation, soreness and bleeding are noted. In the affected area, a positive symptom of Vincent is diagnosed. There is pathological mobility of intact teeth. Limited opening of the mouth, pain when swallowing indicate the germination of tumor cells into the surrounding tissues.
- Jaw x-ray. Radiographic changes characteristic of mandibular cancer are areas of bone rarefaction without clear boundaries with blurred contours. There is no reaction from the periosteum. It is not possible to distinguish a healthy bone from a pathologically altered one.
- Cytology. For cytological examination, the dentist takes a scrape from the ulcerative surface. With central cancer, it is impossible to take the material for examination by puncture due to the high density of the bone tissue of the lower jaw. In this case, bone trepanation is indicated. When enlarged lymph nodes are detected, they are punctured with subsequent cytological examination of the contents.
- Scintigraphy. For the diagnosis of mandibular cancer, a radioisotope method is also used, which is based on the ability of a malignant neoplasm to accumulate the isotope p32.
Differentiate mandibular cancer with chronic osteomyelitis, fibrotic osteodystrophy, eosinophilic granuloma, ameloblastoma, osteoblastoclastoma, tuberculosis, actinomycosis. A physical examination is performed by a maxillofacial surgeon, a dental surgeon, an oncologist.
Mandibular cancer requires combined treatment. At the preoperative stage, a number of orthopedic measures are performed (removal of impressions, manufacture of structures for fixing the remaining part of the jaw in the same position). Movable teeth are not removed due to the high risk of lymphogenic dissemination of cancer cells. This is followed by a course of gamma therapy, 3 weeks after which the operation is performed. With superficial lesions of the alveolar process, through resection is performed, retreating on both sides of the pathological focus.
If the cancer of the mandible is localized in the middle of the lateral part, the bone section from the mental area to the mandibular opening is removed. When the angular zone is involved in the tumor process, resection of half of the mandibular bone is initiated. If the chin is affected, the mandibular bone from corner to corner is to be removed. In the case of metastasis of mandibular cancer to regional lymph nodes, radical excision of the lymphatic apparatus together with subcutaneous tissue, accessory nerve, nodding muscle, submandibular gland is indicated.
When the cancer of the lower jaw spreads to the tongue, palate, ear salivary gland and pharynx, all tissues affected by the tumor process must be removed. Gamma therapy is also performed in the postoperative period. Reconstructive operations aimed at replacing bone defects are indicated to be performed no earlier than a year after surgery. In case of diagnosis of an inoperable malignant tumor, a course of palliative radiation therapy is prescribed. Squamous cell keratinizing cancer cells are insensitive to chemotherapy.
With late detection of mandibular cancer, the prognosis is unfavorable. The absence of relapses and further progression of the tumor process is noted only in a fifth of all operated patients. Relapses occur more often during the first two years after surgery.