In their contribution to the first edition of this Handbook, entitled
"The Teeth," LEHNER and PLENK (1936) discussed the tissues constituting
the "perio- dontium" rather briefly. In contrast to the detailed
paragraphs dealing with, for example, enamel and dentine, the section
(about 40 pages and 20 illustra- tions, mostly drawings) devoted to
periodontal tissues failed to provide a factual review and summary of
the contemporary knowledge and latest developments in research on the
various components of the periodontium. Instead, much of the text was an
attempt to arrive at conclusions from often purely semantic
speculations, playing the various schools of thought against each other,
provid- ing arguments in favor of the authors' views and arguments for
the feasibility and probability of accepting or rejecting the often
diverse opinions, while the reader was referred to the already existing
literature for factual details. Since 1936, however, factual details
ofthe structural biology of the periodon- tal tissues, i. e. their
development, structure, function, and physiology, have been greatly
extended and have been internationally accepted. With much less opin-
ionated belief to cope with, this knowledge has formed the solid
foundation upon which diagnosis, prevention, and treatment in the fields
of clinical perio- dontology, modem orthodontics, and re- and
transplantation procedures of teeth have been built.