Destructive

DESTRUCTIVE, DESTRUCTION (of the) palatal surface of the alveolar process of the upper jaw extends along the edge of the hard palate to the soft palate and then down the lateral wall of the pharynx to the deep cervical lymph glands (lymphoglandulae cervicales profundae superiores mediales). Lymphatic trunks from the internal (lingual) surface of the alveolar process of the lower jaw divide into anterior and posterior: the anterior ones, from the area of the front teeth, pierce the m. mylohyoideus and direct themselves to the anterior mandibular lymph gland (lgl. mandibularis anterior); the posterior ones extend in the submucous layer of the transitional fold and then along the lateral wall of the pharynx to the deep cervical lymph glands (lgl. cervicales profundae superiores mediales), and exceptionally also to the posterior mandibular lymph glands (lymphoglandullae mandibulares posteriores). The lymphatic trunks of the right and left sides often cross the median line. Innervation of the D. is carried out by branches (rami gingivales) from the second and third branches of the trigeminal nerve.

A. Rivkind. Pathology. In cases of traumatic injury, if the integrity of the mucosa is violated, a painful shallow ulcer forms. Besides other traumas, the cause of the ulcer may be defects of a dental prosthesis and thermal and chemical burns (T-ra Jodi, alcohol, caustic alkalis, acids, lapis, etc.). Violations of the integrity of the mucous membrane appear as ulcers of various sizes, irregular contours, covered with a whitish-gray coating of dead epithelium. Depending on the concentration and amount of caustic substance that acted, deeper lesions may also result. Necrosis of the D., reaching the bone, is observed upon entry of the arsenic acid used by dentists onto the D. So-called dyspeptic ulcers—ranging from a point size to 1/2 cm, often very painful, covered with a yellowish coating of ulcer spots, surrounded by an inflammatory zone. They occur singly or in multiples. An ulceration is preceded by a blister of the herpes labialis type. Their appearance is linked to gastrointestinal disorders, which however is not always the case. - Tuberculous lesions are observed both as primary and secondary in the form of shallow ulcers with sharply defined edges, covered with a grayish-yellow coating, sometimes sharply painful and sometimes completely painless. They are solitary and multiple. - Pemphigus vulgaris occurs in the form of single or a few blisters filled with reddish fluid, bursting under slight pressure and leaving traces resembling burns. - Besides a number of local diseases, mainly nonspecific (see Gingivitis) and specific (syphilis, lupus, actinomycosis, etc.), one should note a more or less active reaction of the D. tissue in certain physiological states (pregnancy, menstrual period) and in general diseases—avitaminoses (see Scurvy), blood diseases (alekia, leukemia), diabetes. Thus, hypertrophic gingivitis (see) and epulis of pregnant women are known; vicarious bleeding from the D. has been described during delayed menstruation. In leukemias, thickening of the D. is observed, associated with the appearance of extensive infiltrates and proliferation of cells of the lymphoid or myeloid series in the connective tissue basis, depending on the form of leukemia; the fibrous structure of the connective tissue basis is completely erased at the same time. Hemorrhages are also present, noticeable especially under the epithelium—in the papillary layer and therefore visible even with a simple examination. In some cases, bleeding from the D. is very profuse and persistent, which should be considered when performing biopsies. Gangrenous decomposition of the D. is often noted. In malignant anemia, pallor of the D. is noted. In hemorrhagic diatheses, small spotted hemorrhages (morbus maculosus Werlhofii) occur. In diabetes, inflammation of the D. is noted with a predominance of the exudative moment—purulent discharge, ulcerations. All these changes are localized not only in the D. tissue but also in the deep parts of the paradenecium.

E. Platonov.

DESTRUCTIVE, DESTRUCTION (from Latin destructio—destruction). Destructive—accompanying the loss of structure, a term often used in pathology to denote various (degenerative, necrobiotic, inflammatory, neoplastic) processes accompanied by a certain degree of violation of the normal anatomical structure of certain organs and tissues (up to their complete destruction). Destructive processes can be observed, for example, in the liver during acute yellow atrophy of the liver, during alternation or purulent inflammation of any tissue, during the growth of malignant neoplasms that destroy tissues (destructive growth of tumors), tissue parasitism, etc. The basis of destructive processes lies either simply in necrobiosis or in processes of dissociation, desquamation, and proliferation of cells of a given structural formation. Destructive processes, giving in the end changes of a regressive order, can at the same time be a stage in the development of certain phenomena of a progressive type; thus, the detachment of the tail of a tadpole, the early periods of development of the thyroid gland, the development of bone are accompanied by certain destructive moments, which can be considered here as a physiological, formative process. 759