Tooth Development and Identification
- Tooth development is a complex process that involves the formation and eruption of teeth.
- Primary teeth start forming between the sixth and eighth weeks in utero, while permanent teeth begin forming in the twentieth week in utero.
- Teeth can be categorized into primary (baby) teeth and permanent teeth, with succedaneous teeth replacing primary teeth in the permanent dentition.
- Teeth can be named based on their arch, class, type, and side, with four classes of teeth: incisors, canines, premolars, and molars.
Nomenclature and Numbering Systems
- Teeth can be named using different notation systems, such as FDI, Universal numbering, and Palmer notation.
- The FDI system is used worldwide, while the Universal numbering system is widely used in the United States, and the Palmer notation is still preferred in the United Kingdom.
- The Palmer notation uses symbols and numbers, the Universal numbering system uses letters and numbers, and the FDI system uses a two-digit numbering system based on tooth quadrant and position from the midline.
Anatomic Landmarks and Tooth Structure
- The tooth is attached to the surrounding gingival tissue and alveolar bone by fibrous attachments involving gingival fibers, periodontal ligament fibers, and alveolar bone cortex.
- The crown is the visible part of the tooth above the gum line, while the root is the part below the gum line, with the cementoenamel junction (CEJ) as the boundary between the crown and root.
- The tooth is composed of enamel, dentin, and pulp, and the periodontium is the supporting structure of the tooth in the bone.
Tooth Surfaces, Cusps, and Ridges
- Tooth surfaces include buccal, labial, lingual, occlusal, and incisal surfaces.
- Canines have one cusp, while premolars and molars have multiple cusps.
- Tooth ridges include buccal, labial, lingual, cervical, triangular, and transverse ridges.
Tooth Developmental Features and Specific Tooth Characteristics
- Developmental grooves, embrasures, and mamelons are tooth developmental features.
- Specific characteristics of maxillary central incisors, maxillary lateral incisors, mandibular central incisors, mandibular lateral incisors, canines, maxillary canines, mandibular canines, premolars, and molars are described in detail.
Dental anatomy is a field of anatomy dedicated to the study of human tooth structures. The development, appearance, and classification of teeth fall within its purview. (The function of teeth as they contact one another falls elsewhere, under dental occlusion.) Tooth formation begins before birth, and the teeth's eventual morphology is dictated during this time. Dental anatomy is also a taxonomical science: it is concerned with the naming of teeth and the structures of which they are made, this information serving a practical purpose in dental treatment.
Usually, there are 20 primary ("baby") teeth and 32 permanent teeth, the last four being third molars or "wisdom teeth", each of which may or may not grow in. Among primary teeth, 10 usually are found in the maxilla (upper jaw) and the other 10 in the mandible (lower jaw). Among permanent teeth, 16 are found in the maxilla and the other 16 in the mandible. Each tooth has specific distinguishing features.