The history of orthodontics has been intimately linked with the history of dentistry for more than 2000 years. Dentistry had its origins as a part of medicine.
Addressing an envelope to a post office box address is just like addressing envelopes to any other type of address. Of course, before you can address the envelope, you need the name of the recipient, the post office box number and the city, state and ZIP code.
To determine a ZIP +4 Code you will need to know an address. The last four digits are not specific to a city but to a street address or Post Office Box. This is what an address looks like with the ZIP +4 Code: The first five digits identify the area of the country and the delivery office to which the mail is directed. ZIP Codes start with a zero (0) in the northeast and gradually get higher as you move west. ZIP Codes in the far west start with a nine (9).