Why another series on infectious disease? The question is a fair one in view of the proliferation of monographs, texts, and periodicals on the vast subject of infectious disease. The goal of this series is to provide an additional service to the clinician in the form of clinical information not usually assembled in one convenient volume. One type of monograph presented in this series will cover a specific infection, detailing microbiologic research and clinical aspects. It is hoped that such a compilation will be helpful in both its thoroughness and breadth to the clinician interested in this particular problem. The other type of monograph that this series will provide will discuss a clinical presentation that comprises many possible specific etiologies, such as the present volume, Infections of the Head and Neck. Using this volume as an example, one must presently refer to a multitude of sources to cover the diseases discussed in this text, even though they must all be considered by the clinician in the differential diagnosis of specific patients. Volumes in the series will be multi-authored, giving us the opportunity to invite authorities in each specific area to contribute their expertise and experience. Regular revisions are planned so that each volume will remain as current as it is thorough.