Tooth position representation is a method of numbering every human tooth in dentistry. The upper and lower dentition is divided into four areas: the upper right area is also called area A, the upper left area is also called area B, the lower right area is also called area C, and the lower left area is also called area D. ..
According to the order of dentition from front to back, each tooth is expressed in numerical order, with Arabic numerals 1-8 for permanent teeth and Roman numerals I-V for deciduous teeth.
Common ones are:
The representation of FDI: also known as digital marking, is commonly used in the world. Each tooth is recorded with two Arabic numerals.
Position recording method: also known as Palmer's tooth position representation, it is recorded with quadrant symbols and an Arabic numeral.
Universal numbering system: numbers from 1-32.
Extended data:
Teeth can be divided into incisors, canine teeth, premolars and molars. Each tooth consists of a crown exposed outside the alveolar bone, a root growing in the alveolar bone and a neck between the crown and the root.
The main component of a tooth is dentin, which is surrounded by enamel (at the crown) and cementum (at the root). There is also a periodontal membrane composed of fibers outside the cementum to fix the teeth in the alveolar cavity. There is a dental pulp cavity in the center of the tooth, which is filled with dental pulp and rich in blood vessels and nerves.
People have to grow teeth twice in their lives. The first eruption 1 time is called deciduous teeth, with 5 teeth on the left and right sides of the upper and lower jaws, totaling 20 teeth, which fully grow from 6 months after birth to about 3 years old. At the age of 6 ~ 7, deciduous teeth begin to fall off. The second eruption is called permanent teeth, with 8 teeth on the left and right sides of the upper and lower jaws, totaling 32 teeth. At the age of 6 ~ 7, 1 molars erupted and deciduous teeth began to be replaced. At the age of 13 ~ 14, all deciduous teeth were replaced. But the third molar (also known as "wisdom tooth" or "full head tooth") will not grow until about 20 years old.
Baidu encyclopedia-tooth position representation
Baidu encyclopedia-tooth