Abstract
Dental extractions were performed in five patients with Christmas disease,whilst giving infusions of a concentrate which contained three other clotting factors in addition to factor IX. The therapy was supported locally by inserting a plate over the extraction area, which was removed for cleaning on the third and subsequent days for a short period. The concentrate was extremely well tolerated. There was little or no bleeding following extraction, and several extractions of wisdom teeth were carried out without loss of blood. In order to obtain the required level of factor IX in the plasma at a minimum of 10% after the first infusion and before the extractions, a quantity of the concentrate had to be given which was equivalent to at least two units of factor IX per kg of body weight. A higher level of factor IX was sometimes required in the days following the extractions.