<s>[INST] I was just leaving a dentist office where anesthesia was injected into the path of trigeminal (sp?) nerve (corner of mouth drooping and winking affected). I have allergies and immediately after leaving the dental office I blew my nose. It felt like my nostril collapsed and it is very difficult to breathe through the affected nostril. Thoughts? [/INST] Hello! I read your question and understand your concern. This is probably not due to the nitrous oxide or the local anesthetic. There are a couple of possibilities: One is that if local anesthetic may have been given close to the nasal cavity which can cause irritation and these symptoms. This should be gone within 24 hours. There is also the possibility that anesthesia in a special area on the palate (greater palatine foramen) was given which could also cause these symptoms. Again, they should be relatively short-lived. If the problem persist I recommend you to go to the ORL specialist and have a good physical examination with a nasal spectrum. A full blood work and other tests may be needed. Hope to have been of help! Greetings! </s>