Orthodontic Assistant Practice Exam

In an orthodontic numeric system, what is the designation for tooth number 22?

1. Upper left 4

2. Lower left 3

3. Upper right 7

4. Lower right 4

The correct answer is: Lower left 3

In the orthodontic numeric system known as the FDI World Dental Federation notation, tooth number 22 is designated as Upper Left 2. Each tooth is assigned a number based on the quadrant it is located in, coupled with its position within that quadrant. Tooth number 22 specifically refers to the upper left quadrant. In this system, the first digit indicates the quadrant (1 for upper right, 2 for upper left, 3 for lower right, and 4 for lower left), and the second digit indicates the position of the tooth in that quadrant from the midline outwards, starting with the central incisor at "1." Thus, in quadrant 2, the second digit "2" corresponds to the lateral incisor. This understanding clarifies that in the context of the choices provided, the designation for tooth number 22 aligns with the specifics of tooth numbering and its location in the dental arch.