Twin Block Functional Therapy. Applications in Dentofacial Orthopaedics (1995) Author: William J. Clark Publisher: Times International Publishers Limited, London Price: 95.00, ISBN: 0-7234-21-20-X

The use of myofunctional appliances, when required as an initial phase of treatment, has become widespread within UK orthodontics over the last 20 years. Such systems are commonly employed in orthodontic practice and are taught in most of the Dental Schools. Bill Clark's personal enthusiasm has been largely responsible for the introduction of the Twin Block. He has advocated and promoted its usage, as an 'orthopaedic' type of appliance, which, since it is in two parts, may be worn for longer than most other varieties. The book is presented largely involving numbers of well-illustrated case reports. Though this visibly supports the validity of the therapy, the inclusion of repetitive detail and advice has been difficult to avoid. The foreword, by Dr T. M. Graber, is more a descriptive overview of the contents, with the book aiming to cover all the usages for which Clark has employed this appliance. The most effective aspects of the text are those directed to the reasoning for the therapy, current designs, construction and practical tips on the appliance usage, and its involvement with particular Class II malocclusions. The changes that have occurred in how Clark now employs his appliances are an important reason for reading the book. The wide page format of the volume (which is not too thick) makes it easy to absorb the detail and illustrations. It is a desirable purchase for those wishing to collate and update their information on the thinking of William J. Clark, and at £95.00 should still find a place in all postgraduate centres and Dental School Libraries. Laurence A. Usiskin