Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Go to emergency care now if swelling of the mouth, face, or neck makes it difficult to breathe or swallow, or if there is heavy bleeding that will not stop.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent, same-day dental care if:
A tooth becomes loose or moves after an injury
You have severe dental pain, swelling, fever, or pus
A tooth is knocked out or pushed out of position
New spacing develops quickly with noticeably loose teeth
3
Does any of this apply?
Book an appointment
Arrange a routine dental appointment if a gap is new, getting wider, trapping food, affecting speech or biting, or bothering you.
You should also book an appointment if your gums bleed regularly or appear to be receding.
The article also says
Spacing without pain, injury, looseness, or swelling is not usually an emergency.
Every sign above is quoted from the sofidex article on Widely spaced teeth. If you are not sure, err upward — it is always reasonable to be checked.