Dental anatomy is the study of the classification and morphology of teeth, as well as the study of the principles of occlusion.
Dental anatomy may be considered the study of teeth at three different levels. First, teeth may be studied in terms of the elements of each individual tooth (for example, dentin and enamel). Second, teeth may be studied in terms of classification and numbering systems. Third, teeth may be studied in the larger context of the oral cavity, along with the principles of occlusion and structures that may display pathology such as the gingiva and the temporomandibular joint.
The teeth are derived from the ectoderm and the mesoderm in the embryonic stages of development. Each tooth arises from either the maxilla (the bone that makes up the upper jaw) or the mandible (the bone that makes up the lower jaw). Teeth originating from the maxilla are considered to be in the superior dental arch, or the maxillary dental arch. Teeth arising from the mandible are considered to be in the inferior dental arch, also known as the mandibular dental arch.
Each tooth consists of:
Although each tooth has the same basic structure, some variation exists. Different types of teeth have variation in their roots. Incisors and cuspids have only one root. Maxillary (upper) premolar teeth commonly have two roots, whereas the mandibular premolars commonly have one. The premolars may also have two roots fused to look as one. The molars on the maxillary arch have three roots, while, on the other hand, the molars on the mandibular arch have two roots.
Permanent teeth are divided into four groups based on their function and placement in the jaw. Teeth are given the same name whether they are in the upper or lower jaw. From medial (middle of the mouth) to lateral, the four types of teeth are listed below:
Children who still have their temporary teeth (also known as primary, deciduous, or "baby" teeth) have incisors (four upper, four lower), cuspids (two upper, two lower), and molars (four upper and four lower), but lack pre-molars. There are 20 total primary teeth.
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Author Info: Cindy F. Ovard, RDA, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Nursing and Allied Health, 2002 |