Why should the cast be removed after 14 days?

I certainly understand your eagerness to remove your splint as soon as you can. Without knowing a lot about your case, 2 weeks does seem a little long.  Only your surgeon knows the full details of your surgery, though, so please check with him or her to see if it's possible to remove your splint earlier. Good luck to you. 

Thank you very much for enquire.Swelling after a rhinoplasty depends of the surgery complexity.In this regard, the nasal swelling Post-op It can last from two weeks to two months.To reduce this swelling, I recommend you perform delicates daily lymphatic drainage massage therapy over the face (around the nose) avoid sun exposure, and take pain/inflamation pills, as your surgeron precribe you.Kind regards, Dr. Emmanuel Mallol Cotes

I commonly remove the nasal splint about a week after surgery.  Best to ask your surgeon if it can done sooner. than what you were told.