From Big Medical Encyclopedia

FIBROUS SSTEODISPLAZYYa of JAWS (osteodysplasia maxillarum fibrosa; the synonym a fibrous dysplasia of jaws) — a malformation of jaws in the form of their opukholepodobny deformation, to-rogo is the cornerstone disturbance of ossification. Is one of the most frequent localizations of a fibrous osteodysplasia (see).

In y show I more often in the period of secondary dentition, and also the puberty which is followed by activation of activity of endocrine system, intensive growth of jaws (see) and other bones of a facial skeleton.

Long time version F. h considered the lake an oseruvizm (see). In a crust, time it is proved that the heru-vizm is independent but -

zo l. a form and it is illegal to consider it in group of fibrous displaziya.

Morphologically F. the lake of h is characterized by growth of the cellular and fibrous fabric of a peculiar structure containing separate trabeculas of an unripe bone or sites of incomplete bone formation. Sometimes at damage of jaws development of the fabric which is reminding cement of a fang on the structure (see Teeth) and usually forming single or multiple roundish or branchy conglomerates — tsemen-

1 p kl is observed.

On number of the bones of a facial skeleton involved in patol. process, distinguish moioossalny and noliossal-ny forms F. the lake of h Porazhenke of jaws is quite often combined with damage of other bones of a skeleton.

First sign F. the lake of h usually is disturbance of symmetry of the person, at the same time there are changes of a bite (see), sometimes considerable. With increase in the sizes patol. the center in a jaw secondary disturbances from a prelum of nearby bodies can appear (an exophthalmos, decrease in visual acuity on one eye, the complicated nasal breath, etc.). The face of patients, especially at a poliossalny form, becomes ugly (tsvetn. tab., Art. 208, fig. 11).

The diagnosis is based on a wedge, and rentgenol. data. At damage of an upper jaw in initial stages patol. process is shown on the roentgenogram by moderate inflation of walls of a jaw evenly in the medial and lateral party. Contours of a jaw are kept, Highmore's (maxillary, T.) the bosom is slightly darkened, its form is not changed. Structure patol. the center it is homogeneous, its density approaches density of a surrounding bone, border rather accurate. At increase patol. the center contours of an upper jaw blur, borders of a Highmore's bosom completely disappear (tsvetn. tab., Art. 208, fig. 13). Fast-growing patol. the centers replacing an upper jaw can squeeze an eye-socket, nasal bones. Structure patol. the centers becomes heterogeneous.

At defeat of a mandible rentgenol. the picture is quite uniform. The centers are localized usually in a body and a branch of a jaw. The affected area is blown up, hl. obr. in the vestibular party, a compact (cortical) layer it is sharply thinned. The trabekulyarnost disappears inherent in a healthy bone, the homogeneous melkosetchaty drawing is characteristic. Less often rough trabeculas are defined, to-rye border separate shapeless cells or cysts. Structure patol. center of homogen.

Diagnosis of a poliossalny form F. the lake of h, as a rule, does not cause difficulties. The Moioossalny form needs to be differentiated with sarcoma (see), an osteoblastoclastoma (see), an osteoma (see), ossifying fibroma (see), hron. hyperplastic (dontogenous) osteomyelitis of jaws (see Jaws, pathology). Sarcoma differs in rapid growth, existence of pains, a chaotic arrangement of sites of a lysis and petrification on the roentgenogram. Increase patol. the center at sarcoma is followed by a gap compact - a layer of a bone. At differential diagnosis with an osteoblastoclastoma, ossifying fibroma, an osteoma take into account characteristic rentgenol. signs of the last. For hron. hyperplastic (dontogenous) osteomyelitis existence of so-called causal tooth with resorptive changes at tops of roots, reaction of a periosteum, stratification of a cortical layer, more various picture of reorganization of a bone is characteristic. In difficult cases it is necessary to resort to a biopsy (see).

Treatment of patients with F. the lake of h operational also consists in radical removal patol. the center with the subsequent bone plastics (see) the formed defect (tsvetn. tab., Art. 192, fig. 12, 14).

The forecast for life at F. lake of h favorable. The surgeries undertaken right after detection of a disease at children's age can be prevention of gross cosmetic violations and functions of nearby bodies.

Bibliography: Dmitriyev V. S., Logosov V. S. and Savitsky V. A. Benign tumors of the person, oral cavity and neck, M., 1968; To about l e with about in A. A. New growths of a facial skeleton, M., 1969; To about with and N with to and I am I. S. Fibrous dystrophies and dysplasia of bones, L., 1973; Horn and certain V. V. Clinical forms of a fibrous dysplasia of face bones at children, Stomatology, • 1, page 61, 1969. V. S. Dmitriyeva, V. V. Roginsky.