[Comparative studies of the prognosis of supporting areas].

After measuring average supporting zones in the deciduous and permanent dentition the "leeway space" is determined. The prognostic value of three methods is compared with the average supporting zones in the eugnathic permanent dentition. Separate measurements for the upper and lower jaw in the male and female were done. Correlations between early erupted teeth were considered in the prognosis of the size of the supporting zones. Prognostic values differ, they could be smaller, of equal size or larger compared with the average supporting zones. Average discrepancies range from 0 mm to 1.04 mm. Individual differences are larger amounting up to 3.24 mm. The average differences, but not the individual ones are probably only relevant in important clinical areas.