The authors deal with the problem of a thorough preoperation examination of impacted lower third molars.They describe in more detail the classification systems of impacted lower third molars, which implicate the difficulty of extraction of impacted lower third molars. Factors, which can make the course of the extraction easier, but also more difficult, are presented. For the sake of a successful treatment and the favorable course the authors came to the conclusion by describing the importance of a detailed knowledge of the problems in case.

        Key words: angulation of lower third molars – impactation of lower third molars – classification systems