Reviewed by Larry White

Tom Mulligan has possibly done more than any living author to popularize and simplify the bewildering topic of biomechanics. The second edition of this book will clarify the subject even more, with its amplified illustrations, explanations, and color photographs.

Dr Mulligan had a great advantage before publishing this second edition. He has lectured extensively throughout the world and received feedback regarding biomechanical concepts that continue to confuse readers even as he sought to improve their understanding. He used the questions from those orthodontists to expand and illuminate his narrative.

The second edition has 25 chapters, 2 more than the first edition. Each chapter has a main theme, which is followed with a brief summary called the short story. Bibliographies accompanying the chapters are sparse but relevant, and they will not overwhelm or intimidate readers. He devoted chapters to understanding forces and moments, static equilibrium, and wire-bracket angles; controlling molars in 3 dimensions; applying step, center, and off-center bends; using overlays, differential moments, diastemas, and extraction therapies; and treating open bites.

Nothing disturbs orthodontists more than unexpected consequences during treatment, and Dr Mulligan teaches how to anticipate the effect of any wire used in treatment and how to avoid undesirable results. The movement of teeth does not rely on capricious events, which orthodontists simply observe and try to manage; rather, teeth move in predictable ways, depending upon how and where orthodontists apply the various forces. He explained the principles underlying those movements clearly and precisely.

Dr Mulligan has distilled the understanding and application of orthodontic biomechanical principles in an uncommon manner that everyone can comprehend and, more importantly, apply. He did not waste narrative talking about various brackets or philosophies of orthodontics that the specialty will inevitably replace someday. He explained nothing less than the immutable laws that govern the responses of teeth and bones to orthodontists’ therapies.

I have said before that, if orthodontists were allowed only 1 book in their professional library, they should choose Common sense mechanics because it embraces the most fundamental concepts and universal principles of orthodontics. This second edition magnifies and refines those standards even more.