to elucidate logically. The intelligent clinician can always use and apply such workbut then that is what research is all about! At 2C15.00 the book is well produced but priced at 1976 prices. If you cannot afford to buy it, borrow it! A. J. RODESANO
A Colour Atlas of General Surgical Diagnosis. Wolfe. 1976. pp. 448, price 215.00.
By WILLIAM F. WALKER. London:
For those people already familiar with this series this book will form a very valuable addition to the range. It sets out to demonstrate photographically a wide range of surgical cases and their typical appearances. Each colour photograph is accompanied by a very short two or three line explanatory text. The reproduction of the colour photographs throughout is of an excellent standard as too are the appropriate reproductions of x-ray plates. Inevitably the emphasis tends to be on the photogenic cases, rather than on the frequency of occurrence of any given condition but the book loses nothing for this. By comparison with the book on orofacial disease it does of course tend to be somewhat sketchy in its coverage of any single system, but it nevertheless provides the reader with a clear visual impression of many of the common conditions which might be presented for spot diagnosis. In this context, the book is of extreme value, not only to the undergraduate studying general surgery, but to the postgraduate working for his Final Fellowship in Dental Surgery. It is in no way an alternative to a good standard text book on General Surgery, but rather an adjunct to the basic text, giving a better clinical impression of the appearance of many commonly occurring conditions. J. Ll. WILLIAMS of Human Mandibular Movement by J. M. GOODSON and E. JOHANSEN. Monographs in Oral Science V editeci by H. M. MEYERS, Basel: S. Karger. 1975, p. 80, 50 figs., 20 tab., price $38.75.
The authors of this monograph describe a technique for measurement of jaw movement and a computerised analytical method for calculating and displaying the three-dimensional velocities and pathways of selected points on the mandible. A short theoretical section introduces the idea of position vectors and direction cosines and demonstrates that it is necessary to measure three linear and three angular displacements in order to define the position of a body in space. There follows a brief description of a system to measure these six variables for mandibular movement. The system is fitted to the buccal surfaces of the mandibular teeth and the patient immobilised with a plaster headcap. Movements of the mandible are transmitted to electrical devices which produce analogue outputs of their linear and angular displacement. These analogue outputs are then digitised and used as input data for the computer programme which displays in analogue form the positions and velocities required. The largest section of the book describes the results obtained for a single normal subject carrying out five jaw movements; chewing, opening and closing, right- and left-lateral and protrusive. The amount of work involved in the analysis is considerable and only single jaw movement cycles are analysed. The analogue recordings of the jaw movements which form the basis of the analysis are shown and it is clear that there is considerable difference between the repeated chewing cycles. It is impossible to see what these differences mean in actual jaw movement as the computer process