From Big Medical Encyclopedia

DYSOSTOSIS (dysostosis; Greek dys-+ osteon a bone + osis) — the disturbance of development of bones which is the cornerstone of inborn hereditary family diseases of bone system. Most often there are anomalies of development of bones of a skull in combination with other symptoms, however multiple and generalized damages of bones of a skeleton meet. The term «Dysostosis» is applied to generalized damages of a skeleton — chondrodystrophias (see), to a gargoilizm (see), to bone formation imperfect (see) etc.

The most important kinds of D.: clavicular and cranial, craniofacial, maxillofacial and maxillary черeпной.

Clavicular and cranial Dysostosis

Fig. 1. A clavicular and cranial Dysostosis (Sheytkhauer's syndrome — Mari — Sentona) at three sisters. Lack of clavicles at two sisters leads to full contact of shoulders.

The clavicular and cranial Dysostosis (Sheytkhauer's syndrome — Mari — Sentona) is characterized by a hypoplasia of cover bones of a skull in combination with a full or partial underdevelopment of one or both clavicles, i.e. disturbance of development of so-called hymenoid bones. Not fusion or late fusion of cranial seams and fontanels is characteristic of D. of this look, brachycephaly (see) with dominance of expansion of a calvaria in the lateral directions, an outstanding forehead, a hypoplasia of facial bones, hl. obr. an upper jaw, causing a pseudo-progeny (the seeming increase in a mandible). Disturbance of development of jaws is followed by delay of a teething. Lack of clavicles or a partial underdevelopment with defect of internal, middle or outside parts leads them to increase in mobility of a shoulder girdle, and at their total absence — to full contact of shoulders (fig. 1).

The described changes often are followed by deformations of a backbone, bones of top and bottom extremities, feet, haunch bones. Anomaly is inherited on recessive and dominant type, can be family.

At a clavicular and cranial dysostosis numerous changes radiological come to light from a skeleton, however changes of clavicles and bones of a skull are most characteristic. Defects of clavicles are symmetric to a thicket and can be the different sizes: from clavicles, small to total absence. Most often there is no acromial end of a clavicle. The free end of the rest is rounded off, covered with the closing bone plate and connected dense fibrous tyazhy with an acromial shoot of a shovel. On the course of a fibrous tyazh bone inclusions sometimes are found.

At rentgenol, a research of a skull the brachycephaly is defined: the neurocranium is increased in the diameter and reduced in a front-back size. The base of skull is shortened in transverse direction and a little extended in longitudinal. Bones of the arch, especially frontal, are thinned and as if inflated, considerably being given in the parties. The front fontanel remains nezarashchenny. In places of decussation of seams also additional fontanels or additional bone inclusions in seams can be observed. Bones of a facial skull are small, genyantrums are underdeveloped. The sizes of a mandible are not changed. Anomalies of a bite, an arrangement, a form and terms of a teething are found.

At a research of a skeleton of a trunk and extremities deviations in development of a number of bones can be found: the reduced sizes of shovels, a sacrum, pelvic bones with lack of merge among themselves pubic, sciatic and ileal bones and an underdevelopment of a pubic symphysis; an underdevelopment of proximal departments of hips with their varus deformation; shortening or lack of nail tuberosity at trailer phalanxes of fingers of brushes and feet; not fusion of handles of vertebrae.

At multiple damage of a skeleton existence of characteristic changes of clavicles does rentgenol, the diagnosis reliable.

Craniofacial Dysostosis

Fig. 2. Enzygotic twins of 13 years with a craniofacial dysostosis (Kruzon's syndrome). Widely placed eyes are characteristic, squint, a hypoplasia of an upper jaw is expressed.

Craniofacial Dysostosis (Kruzon's syndrome, hypertelorism) — an underdevelopment of bones of a skull, brain and upper jaw in combination with premature closing of cranial seams, exophthalmos (see), squint (see), nystagmus (see), visual disturbance. The forehead in a nose bridge is hilly, eyes are widely placed (fig. 2), Nov of a peculiar ankyroid form («a beak of a parrot»), a hypoplasia of an upper jaw, a pseudo-progeny; in sharply expressed cases decrease in intellectual development is observed. It is inherited on dominant type.

Radiological changes of a skull come to light. Into the forefront the characteristic dekonfiguration of the head and disturbance of normal ratios between a brain and facial skull acts: the first is reduced in sizes, has almost spherical shape, seams of a zarashchena, manual impressions are strengthened. Bones of a calvaria are thinned, knaruzh in a front fontanel are a little stuck out. The base of skull is shortened and deepened, the area of the Turkish saddle is narrowed, eye-sockets are flattened.

Bones of a facial skull are small: the upper jaw and nasal bones are underdeveloped, the mandible considerably is given forward owing to what the sharp deflection of a nose inside is formed.

Fig. 3. The child with a maxillofacial dysostosis. The located palpebral fissures, disturbance of development of teeth wide slantwise are characteristic.

A maxillofacial Dysostosis

the Maxillofacial Dysostosis (Berri's syndrome — Franchesketti, Franchesketti's syndrome — Tsvalena) — a hypoplasia of hl. obr. a mandible and malars, a macrostomia (a peculiar «fish» or «bird's» person), the located palpebral fissures (fig. 3) wide slantwise, with the vyvorochenny and mown from top to bottom centuries and colobomas in outside departments, blind fistulas from corners of a mouth to ears, yazykovidny pilosis of cheeks, disturbances of development of teeth, deformation of auricles, sometimes a middle and inner ear with development of deafness, removable operation. Contrary to Kruzon and Aper's syndromes (see Aper a syndrome) is defined strong development of frontal sinuses. Deformation of a thorax and backbone meets. It is inherited on dominant type.

A maxillary and cranial Dysostosis

the Maxillary and cranial Dysostosis (a syndrome Peters — Hevelsa) — a hypoplasia of an upper jaw, zygomas, an open bite, a progeny (a vystoyaniye of a mandible), shortening of front department of a base of skull. Anomaly is inherited on dominant type.

There are other forms cranial D.: Gegenkhar, Roben, François's syndromes, etc. Outward of patients with various forms D. is characteristic. Remains all life, does not give in to operational correction, almost does not demand differential diagnosis with other diseases. In doubtful cases an important diagnostic method is rentgenol, the research.

Distinguish so-called incomplete types of the listed D. when not all take place the symptoms characterizing them. Separate signs can be combined in various combinations, making as if transition types of.

The forecast for life favorable.

Bibliography: Alekseev V. A. Case of a cranial and clavicular dysostosis, Vestn, rentgenol, and radio-gramophones., No. 3, page 80, 1974; Kosinskaya N. S. Disturbances of development of the bone and joint device, page. Stars, etc., L., 1966; Kruchinskiyg. B. Rare inborn syndromes of the person and jaws (in borders of the first and second branchiate arches), Minsk, 1974, bibliogr.; P e y N - e r S. A. Radiodiagnosis of diseases of bones and joints, book 1 — 2, M., 1964; Romodanov A. The item and JI I am Hz of e of the Tax Code about D. S. Craniofacial Dysostosis, Zhurn, neuropath, and psikhiat., t. 72, No. 10, page 1487, 1972, bibliogr.; Fleischer-Peters A. Kiefermissbildungen bei Dysostose-Syndromen des Schadels, Dtsch, zahnarztl. Z., Bd 24, S. 932, 1969; Humange-netik, hrsg. v. P. E. Becker, Bd 2, S. 489, Stuttgart, 1964, Bibliogr.; Hylton R. P. a. Albright J. E. Cleidocranial dysostosis, J. oral Surg., v. 28, p. 682, 1970; T e s s i e r P. The definite plastic surgical treatment of the severe facial deformities of craniofacial dysostosis, Plast. reconst. Surg., v. 48, p. 419, 1971.

T. P. Vinogradova; I. G. Lagunova (rents.).