Edward P. R. Ryan was a dental surgeon in the U.S. Army at the beginning of the 20th century; this guide is an eye-opening history of dental practice during the era. Designed as a practical primer for aspiring and practicing dentists, this book includes the basics of dental anatomy, various bacterial conditions of the mouth, plus types of fracture and dislocations of the jaw. Typical causes of dental pain, be it simple toothache or the more serious occurrences of nerve pain, are explained. Common surgeries on the mouth, and the pitfalls of post-operative care, receive detailed examination. While Ryan's treatments and suggestions are outdated, he does make several poignant observations: he notes a deep correlation between dental hygiene and the emergence of disease in the teeth and gums. The most common patient he treated either had never cleaned their mouths, or had only done so on occasion. Importantly, this book demonstrates new technologies such as X-rays, which afforded Ryan and other army dentists a better capacity for diagnosis and treatment. In all, this book contains some eighty images - photographs and illustrations - of the dental practice undertaken by Edward Ryan.