[Observation of gaps between the teeth classified by Eichner as type A]

1,030 sets of teeth classified by Eichner as type A (single gap between the teeth) were examined in view to tooth shifting, tipping and periodontal condition on the gap's antagonists and the gap's neighbours. If it is necessary to close the gap with prosthetic means is dependent on the mode of individual reaction which is estimated on a long-term-observation of gap areal (clinical and radiographic). The stability of position of gap antagonist or gap neighbour point to a positive bone factor (by Glickman). Only those cases ought not to treat.