[The extraoral fistula (author's transl)].

Extraoral fistulas, whether primary or as the residue of an abscess, have different causes. According to case reports in the literature and from clinical experience the dentogenous cause is the more frequent. For this reason a possible tooth involvement should be ruled out before therapy, loss of dental pulp of various origin and periodontal diseases should be excluded, otherwise the treatment must begin with the cause, after which further intervention is usually superfluous.