![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Universal_Numbering_System.svg/220px-Universal_Numbering_System.svg.png)
The Universal Numbering System, sometimes called the "American System", is a dental notation system commonly used in the United States.[1][2]
Most of the rest of the world uses the FDI World Dental Federation notation, accepted as an international standard by the International Standards Organization as ISO 3950.[3] However, dentists in the United Kingdom commonly still use the older Palmer notation despite the difficulty in representing its graphical components in computerized (non-handwritten) records.
Left and right[edit]
Dental charts are normally arranged from the viewpoint of a dental practitioner facing a patient. The patient's right side appears on the left side of the chart, and the patient's left side appears on the right side of the chart.
The labels "right" and "left" on the charts in this article correspond to the patient's right and left, respectively.
Universal numbering system[edit]
Although it is named the "universal numbering system", it is also called the "American system" as it is only used in the United States.[4] The uppercase letters A through T are used for primary teeth and the numbers 1 - 32 are used for permanent teeth. The tooth designated "1" is the maxillary right third molar ("wisdom tooth") and the count continues along the upper teeth to the left side. Then the count begins at the mandibular left third molar, designated number 17, and continues along the bottom teeth to the right side. Each tooth has a unique number or letter, allowing for easier use on keyboards.
Permanent dentition | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
upper right | upper left | ||||||||||||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
32 | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 |
lower right | lower left | ||||||||||||||
Primary dentition | |||||||||||||||
upper right | upper left | ||||||||||||||
A | B | C | D | E | F | G | H | I | J | ||||||
T | S | R | Q | P | O | N | M | L | K | ||||||
lower right | lower left | ||||||||||||||
Alternate system for primary dentition | |||||||||||||||
upper right | upper left | ||||||||||||||
1d | 2d | 3d | 4d | 5d | 6d | 7d | 8d | 9d | 10d | ||||||
20d | 19d | 18d | 17d | 16d | 15d | 14d | 13d | 12d | 11d | ||||||
lower right | lower left |
Tooth numbering[edit]
![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Comparison_of_dental_notations.svg/350px-Comparison_of_dental_notations.svg.png)
Permanent teeth and their assigned numbers (Universal Tooth Numbering System)
Upper right
- 3rd molar (wisdom tooth)
- 2nd molar (12-yr molar)
- 1st molar (6-yr molar)
- 2nd bicuspid (2nd premolar)
- 1st bicuspid (1st premolar)
- Cuspid (canine/eye tooth)
- Lateral incisor
- Central incisor
Upper left
- Central incisor
- Lateral incisor
- Cuspid (canine/eye tooth)
- 1st bicuspid (1st premolar)
- 2nd bicuspid (2nd premolar)
- 1st molar (6-yr molar)
- 2nd molar (12-yr molar)
- 3rd molar (wisdom tooth)
Lower left
- 3rd molar (wisdom tooth)
- 2nd molar (12-yr molar)
- 1st molar (6-yr molar)
- 2nd bicuspid (2nd premolar)
- 1st bicuspid (1st premolar)
- Cuspid (canine/eye tooth)
- Lateral incisor
- Central incisor
Lower right
- Central incisor
- Lateral incisor
- Cuspid (canine/eye tooth)
- 1st bicuspid (1st premolar)
- 2nd bicuspid (2nd premolar)
- 1st molar (6-yr molar)
- 2nd molar (12-yr molar)
- 3rd molar (wisdom tooth)
See also[edit]
References[edit]
- ^ "Tooth Numbering Systems". Oral Health Topics A–Z. American Dental Association. Archived from the original on November 2, 2006. Retrieved 2014-05-26. (www.archive.org link)
- ^ American Dental Association (August 2022). "Universal Tooth Designation System" (PDF). ValueSet - Universal Tooth Designation System ada.org. Archived (PDF) from the original on 2023-03-06. Retrieved 2023-03-10.
- ^ ISO 3950 Updated – Dentistry Designation System
- ^ "Histology: A Text and Atlas by Michael H. Ross • Wojciech Pawlina".
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction