Swollen face

My daughter (aged 18), had two filling done two days ago on opposite side of her mouth.  Immediately one side of her face swelled up but the dentist paid this no notice.  I took her back the following day because I was worried.  The dentist said it may have been caused by an allergy to the anaesthetic (she's previously had a filling but never this reaction) or he may have injected too close to the nerve.  He prescribed ibuprofen and antibiotics, which she's been taking.   Her face is still very swollen.  She can't close or open her mouth fully and is having difficulty eating. The site of the filling is fine and isn't causing her any pain at all, the problem is with her face - specifically her lower cheek and up into her jaw 'hinge'.  I feel I haven't been given a proper reason for this, and I'm very worried about it.  Is it just a matter of time before the swelling goes?  Should I take her to a different dentist?  Are there likely to be any longer term problems, or am I just worrying too much?  Thanks.

[Ramin Mehregan, DMD]

Dear concerned mother
Swelling of tissue after dental injection is not a clinical syndrome but a clinical sign of some disorder. Causes are:
1) Trauma during injection
2) Infection
3) Allergy: localized swelling could occur due to vasodilation secondary to histamine release (if that was the case she would she would have also shown swelling of tongue and larynx and would have compromised her ability to breath)
4) Hemorrahge
5) Injection of irritating solutions such as alcohol or cold sterilizing solution

If the swelling was due to trauma or irritating solutions it will resolve in 1-3 days. If there is hemorrahge the swelling could take up to 2 weeks to resolve. (you should also be able to see bluish discoloration in the area). If the swelling is due to an infection it could progressively become more intense. The symptoms are usually pain, swelling, dysfunction of the lower jaw such as movements, etc. If the swelling does not resolve in 3 days she needs to be on Antibiotic therapy.
If the swelling was caused by an allergy, again she would have had signs of airway obstruction and need for immediate hospitalization.
Hope this will give you an answer.
Sincerely
Dr. Mehregan