Final answer:
The first character of the Air Force Specialty Code (AFSC) for medical or dental fields is the number 4, indicating a medical professional's job function within the Air Force.
Step-by-step explanation:
The first character of the Air Force Specialty Code (AFSC) that is associated with medical or dental fields is the number 4. Each AFSC is a unique code that the United States Air Force uses to identify an enlisted member's job functions. For those in the medical or dental fields, the AFSC codes start with 4 indicating that the individual is part of the medical professionals within the Air Force. For example, a 4A would indicate a medical administrator, 4D would signify a medical/dental lab technician, and so forth.