The code "40" refers to the lower right quadrant of the oral cavity. It does not represent a specific tooth number.
According to the Area of Oral Cavity Codes reference:
| Area of Oral Cavity Code | Description |
|---|---|
| 10 | Upper right quadrant |
| 20 | Upper left quadrant |
| 30 | Lower left quadrant |
| 40 | Lower right quadrant |
Therefore, 40 is not a tooth number but a dental quadrant code.
