[Behavior of the fibrin-stabilizing blood coagulation factor XIII in hemorrhages after tooth extractions].

The influence of the fibrin-stabilizing coagulation factor XIII is necessary for the formation of a stable blood clot. The factor is not included in the usual global coagulation tests. The presence of lowered concentrations of this factor can be congenital or acquired as a result of various diseases. A lowered concentration of factor XIII was demonstrated in six patients with otherwise normal coagulation tests during a secondary hemorrhage a few days after an extraction. The hemorrhage was attributed to the lowered resistance of the instable blood clot over against the fibrinolytic characteristics of the buccal cavity milieu.