For asymmetry of teeth arc that is defined by single-side removal of the first premolar non-symmetric placement of anti-measures is character, that is reflected in the main linear parameters of the complete and incomplete side of arc.

The objective of the research is to define linear parameters of asymmetric dent-alveolar arcs, defined by the lack of anti-measure for one of premolars on the upper jaw under normadentism of constant teeth and mesognatic shape of dent-alveolar arcs.

We have carried out a biometric study of 17 jaw models, obtained from patients of both sexes of the fist maturity period after orthodontic treatment with single-side removal of the first premolar of the upper jaw. Measures of the both arc sides we taken, one of them was named complete, and another - incomplete (with lack of one of premolars) without signs of laterality.

To define main parameters of the main frontal point, located in contact place of medial cutting teeth of the upper jaw near the cutting edge, we have placed a perpendicular to the line that links distal surfaces of the second molars. This line was called as «sagittal arc line». From the centre of the distal surface of each tooth we have placed a perpendicular to the sagittal arc line, it allowed us to measure transversal (W) and sagittal (D) parameters of arcs. Frontal-distal diagonal of dent-alveolar arc (FD) was measured from the frontal point to the point, located at the centre of distal surface of a certain tooth.

The results have shown that in the front arc department the size of frontal-distal diagonal didn't have any signs of laterality and, in general, equaled 22,7 ± 1,94 mm. At the same time, arc depth up to the fang level at the complete side was shorter by about 4,2 ± 1,21 mm, and arc width was bigger by 2,8 ± 0,93 mm.

The most evident alterations took place in the area of chewing teeth. Frontal-distal diagonal at the complete arc side was bigger by 4,6 ± 0,82 mm, up to the level of constant molars - by 4,3 ± 0,95 mm, and up to the second molars - by 3,1 ± 0,79 mm, it was conditioned by mesial shift of chewing teeth to the defect.

The width of dent-alveolar arc at the complete side up to second premolars equaled 22,3 ± 2,4 mm, to first constant molars - 24,8 ± 2,6 mm, to second molars - 28,75  ± 2,5 mm the width of dent-alveolr arc of the incomplete side to second premolars equaled 18,35 ± 1,9 mm, to fist constant premolars - 19,6 ± 2,3 mm, to second molars - 21,8 ± 2,4 mm. Besides, the depth of dent-alveolar arc at the complete side was smaller than it was at the incomplete side, that was conditioned by an asymmetric shape of dent-alveolar arc.

Thus, we have outlined reliable differences of the main parameters of dent-alveolar arcs on both complete and incomplete sides.

The work is submitted to the Scientific International Conference «Innovative Medical Technologies», France (Paris), 15-22 March 2012, came to the editorial office on 14.02.2012.