Tooth Types :
Tooth types with their specific anatomy are related to mas- ticatory function of the tooth and to its role in speech and esthetics . Form and function of each type are somewhat similar for BOTH primary and permanent dentitions. Types include incisors, canines, premolars, and molars; premolars (bicuspids) ONLY in permanent dentition.
A. Incisors: bite and cut food because of triangular prox- imal form.
B. Canines (cuspids): pierce or tear food because of prominent cusp and tapered shape.
C. Premolars (bicuspids): assist molars in grinding food because of broad occlusal surface and prominent cusps and assist canines in piercing and tearing food with their cusps.
D. Molars: grind food, assisted by premolars, because of broad occlusal surfaces and prominent cusps.
Tooth Surfaces :
Includes facial (buccal), lingual, occlusal, and interpro- mixal surfaces. Interproximal surfaces are complex (as is the care of the area).
A. Contact point: point on the proximal surface where two adjacent teeth actually touch each other (if not present, may have an open contact).
B. Interproximal space: area between two teeth.
1. P art of the interproximal space is occupied by the interdental papilla.
2. P art of the interproximal space not occupied is called the embrasure.
C. Embrasure: area bordered by interdental papilla, proximal surfaces of the two adjacent teeth, and con- tact point.
1. I f there is no contact point between the teeth, the area between is a diastema instead of an em- brasure
D. Height of contour (crest of curvature):
1. Located on the mesial and distal surfaces at the contact area (also greatest elevation of the tooth either incisocervically or occlusocervically on a specific surface of the crown).
2. Also located on the facial and lingual surfaces as is easily seen when viewing the tooth’s profile from the proximal.
Tooth Designation :
Two systems of tooth designation are widely used. These systems offer standardized method of identifying teeth for purposes of treatment, identification, documentation. Palmer method is older method used by orthodontists and uses quadrant and position within it in numbering.
A. Universal Tooth Designation System: used in the United States; adaptable to electronic data transfer (used on the NDHBE):
1. Primary teeth are designated by the capital letters A through T, consecutively, starting with the max- illary right second molar, moving in a clockwise fashion, and ending with the mandibular right sec- ond molar.
2. Permanent teeth are designated by numbers #1 through #32, consecutively, starting with the max- illary right third molar, moving in a clockwise fashion, and ending with the mandibular right third molar.
B. International Standards Organization Designation System (ISO System) by the World Health Organiza- tion: used internationally; adaptable to electronic data transfer; teeth are designated by a two-digit code; first digit indicates quadrant, second indicates the tooth in quadrant.