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Crowded, irregular, and protruding teeth have been a problem for some individuals since antiquity, and attempts to correct this disorder go back at least to 100 BC. Primitive (and surprisingly well designed) orthodontic appliances have been found in both Greek and Etruscan materials. As dentistry developed in the eighteenth and nineteenth centuries, a number of devices for the "regulation" of the teeth were described by various authors and apparently used sporadically by the dentists of that era.
After 1850, the first texts that systematically described orthodontics appeared, the most notable being Norman Kingsley' s Oral Deformities. Kingsley (Fig. 1-1), who had a tremendous influence on American dentistry in the latter half of the nineteenth century, was among the first to use extraoral force to correct protruding teeth. He was also a pioneer in treatment of cleft palate and related problems.

Fig. 1-1 Norman Kingsley’s self-portrait, which was a noted sculptor and artist as well as an influential dentist, also served as Dean of the school of dentistry at New York University.

Despite the contributions of Kingsley and his contemporaries, their emphasis in orthodontics remained the a paid to the dental occlusion, and since it was common practice to remove teeth for many dental problems, extractions for crowding or malalignment were frequent. In an era when an intact dentition was a rarity, the details of occlusal relationships were considered unimportant.
In order to make good prosthetic replacement teeth, it was necessary to develop a concept of occlusion, and this occurred in the late 1800s. As the concepts of prosthetic occlusion developed and were refined, it was natural to extend this to the natural dentition. Edward H. Angle (Fig. l-2) whose influence began to be felt about 1890 can be credited with much of the development of a concept of occlusion in the natural dentition. Angle' s original interest was in prosthodontics, and the taught in that department in the dental schools at Pennsylvania and Minnesota in the 1880s. His increasing interest in dental occlusion and in the treatment necessary to obtain normal occlusion led directly to his development of orthodontics as a specialty, with himself as the "father of modern orthodontics".

Fig. 1-2 Edward H. Angle in his early forties, near the time that he established himself as the first dental specialist. From 1905 to 1928, Angle operated proprietary orthodontic school in St. Louis, New London, Connecticut, and Pasadena, California, in which many of the pioneer American orthodontists were trained.

The publication of Angle' s classification of malocclusion in the 1890s was an important step in the development of orthodontics because it not only subdivided major types of malocclusion but also included the first clear and simple definition of normal occlusion in the natural dentition. Angle' s postulate was that the upper first molars were the keys to occlusion lower molars should be related so that the mesiobuccal cusp of the upper molar occludes in buccal groove of the lower molar. If this molar relationship existed and the teeth were arranged on a smoothly curving line of occlusion (Fig. 1-3), then normal o本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。