Biological Mechanisms of Tooth Movement. Группа авторов
(23–79), expressed opposition to the extraction of teeth for the correction of malocclusions, and advocated filing elongated teeth “to bring them into proper alignment.” Plinius was evidently the first to recommend using files to address the vertical dimension of malocclusion, and this method had been widely used until the nineteenth century (Weinberger, 1926).
Figure 1.3 Aulus Cornelius Celsus (25 BCE–50 CE).
(Picture courtesy: http://www.general‐anaesthesia.com/.)
There were few, if any, known advances in the fields of medicine, dentistry, and orthodontics from the first to the eighteenth centuries, with the exception of Galen (131–201), who established experimental medicine, and defined anatomy as the basis of medicine. He devoted chapters to teeth, and, like Celsus, a century earlier, advocated the use of finger pressure to align malposed teeth. Galen advocated the same method to that of Celsus through his writings in 180 CE, which stated that a tooth that projects beyond its neighbors should be filed off to reduce the irregularity (Caster, 1934). Another exception was Vesalius (1514–1564), whose dissections produced the first illustrated and precise book on human anatomy.
For reasons connected with the church, Galen and his writings monopolized medicine for more than a thousand years. However, there were minor advancements in European medicine during that protracted era and advancements evidenced by writings of Muslim physicians from Arabia, Spain, Egypt, and Persia.
Orthodontic treatment during the Industrial Revolution: Emergence of identification of biological factors
The writings of authors in the Middle Ages were mainly repetitions of what already existed, and there were no new references to mechanical principles for correcting dental irregularities. It was Pierre Fauchard (1678–1761), the father of dentistry and orthodontics (Figure 1.4), who organized previous knowledge and opinions, and provided an extensive discussion on the rationale for numerous clinical procedures (Wahl, 2005a). His book titled Le chirurgien dentiste (The Surgeon‐Dentist) was published in two editions, the first in 1728 and the second in 1746. The second edition described a few orthodontic cases (Volume II, Chapter VIII) along with an extensive description of appliances and mechanical principles. This book is considered to be dentistry’s first scientific publication. Fauchard also advocated keeping young patients under observation and removing long‐retained deciduous teeth to prevent irregularity in the permanent dentition. He also stated that blows and violent efforts may increase the chances of developing an irregular tooth arrangement and reported that the greatest incidence of these mishaps occur in the incisor and canine regions. Most of the appliances he fabricated were made of gold or silver and were designed according to the patient’s needs, marking the beginning of “customized orthodontic appliances” (Figure 1.5). The orthodontic appliance described by Fauchard used silk or silver ligatures to move malposed teeth to new positions, and “pelican” pliers for instant alignment of incisors, facilitated by bending of the alveolar bone. After placing teeth in position with pelican forceps, he retained them with silver ligatures or lead plates adjusted on either side, over which linen was placed and sewed into position with needle and thread, between interproximal spaces and over the occlusal surfaces of the teeth. This device, named bandeau, marked the beginning of the era of modern orthodontic appliances and their utilization in treating malocclusions (Asbell, 1990).
Figure 1.4 (a) Pierre Fauchard (1678–1761), the father of dentistry and orthodontics.
(Source: Vasconcellos Vilella, 2007.)
(b) His book titled Le chirurgien dentiste(The Surgeon‐Dentist).
(Source: Picture courtesy: Andrew I. Spielman.)
Figure 1.5 (a) Dental pelican forceps (resembling a pelican’s beak).
(Source: Courtesy of Alex Peck Medical Antiques.)
(b) Bandeau–the appliance devised by Pierre Fauchard.
(Source: Vasconcellos Vilella, 2007.)
John Hunter (1728–1793), in 1778, in his book titled A Practical Treatise on the Diseases of the Teeth, stated that teeth might be moved by applied force, because “bone moves out of the way of pressure.” This book, along with his previously published book, titled The Natural History of Human Teeth, marked the beginning of a new era in the practice of dentistry in England (Wahl, 2005a). Hunter recognized the best time to carry out orthodontic treatment to be the youthful period, in which the jaws have an adaptive disposition. In 1815, Delabarre reported that orthodontic forces cause pain and swelling of paradental tissues, two cardinal signs of inflammation.
Up to 1841, about a century after Fauchard had written a chapter about orthodontics, there was no single book devoted entirely to orthodontics alone, but in 1841, Schange published a book solely confined to orthodontics (Wahl, 2005a), which served as a stimulus for conducting investigations in this defined clinical field. Moreover, this book initiated the notion that orthodontics is a unique dental specialty. Schange described the tooth‐eruption process, causes of irregularities, their prevention, and classified defects of conformation. In treating irregularities, Schange took a different view from Fauchard, who had advocated the use of radical procedures. He warned practitioners of the attendant danger to the tooth when these procedures were performed and favored application of delicate forces in a continuous manner, hence being the first to favor light orthodontic forces. He recommended silk ligatures to apply light forces, and gold for constructing bands and plates, and recognized the importance of retaining teeth after OTM.
Figure 1.6 Norman William Kingsley (1829–1913).
(Source: Dr Sheldon Peck, University of North Carolina at Chapel Hill. Reproduced with permission of Dr Sheldon Peck.)
Samuel Fitch’s book titled A System of Dental Surgery, published in 1835, marked the beginning of a new era in the practice of dentistry in America. He drew attention to the mobility of teeth within the alveolar process during OTM and characterized the growth period as the time for attaining best results of treatment. Norman Kingsley’s treatise on “oral deformities” (1880) had an immediate impact, by placing orthodontics as a specialty, which requires more than general information to solve many of the problems its practitioners face. The book emphasized the importance of basic biology and mechanical principles while studying orthodontia as a science. While describing structural changes due to tooth‐moving forces, Kingsley (Figure 1.6) stated that “the physiological fact being that bone will yield or become absorbed under some influences, and also be reproduced … and in moving teeth, the power used creates a pressure which produces absorption.” He also stated that “the function of absorption and reproduction may or may not go coincidentally, simultaneously and with equal rapidity.”