DIASTEM (diastema; grech, diastema an interval) — the anomaly of position of teeth which is expressed an interval between the central cutters.
Belongs to widespread anomalies (7 — 19%); on an upper jaw meets more often (fig.).
To its emergence the shortened bridle of a lip, the wrong arrangement of rudiments of the central cutters, inborn lack of side cutters, existence of accessory teeth, discrepancy bring in the sizes of an alveolar shoot and teeth (small teeth), addictions (biting of nails, a pencil, etc.); quite often D. is family feature and is transferred as an ancestral feature.
Size D.: from 0,6 mm to 6 — 7 mm. Small D. can be considered as norm; the wide interval between teeth is, generally an esthetic shortcoming; besides, at it pronouncing tooth concordants is at a loss. It is recommended to eliminate D. before eruption of side cutters, i.e. in 7 — 8 years.
Treatment orthodontic; consists in rapprochement of the central cutters by means of special devices. sometimes in combination with surgical intervention (removal of accessory teeth, a compact osteotomy between the central cutters, movement of the place of an attachment of a bridle of a lip). After D.'s elimination it is necessary to hold the moved central cutters before eruption of side cutters by means of any retentsionny adaptation or a temporary removable prosthesis. If by orthodontic methods it is impossible to liquidate D., napr, in the presence of a crack more than 5 mm wide and small teeth, at inborn lack of side cutters, it is reasonable to cover cutters with artificial crowns with plastic facing, liquidating thus the available interval.
Bibliography: Kalamkarov of X. And., etc. Distribution of dentoalveolar anomalies at children of preschool and school age, Stomatology, t. 52, No. 4, page 50, 1973, bibliogr.; T e of l of e and e in and G. T. Treatment of a diastem, in the same place, t. 51, No. 1, page 36, 1972, bibliogr.; Horoshilkina F. Ya. Etiology, clinic and treatment of a diastem, in the same place, No. 2, page 77, bibliogr.; In i s h and of a S. E. Management of diastemas in orthodontics, Amer. J. Ortho-dont., v. 61, p. 55, 1972.
O. I. Efanov.