I'm sorry you're going through this. Unfortunately it does sound like there is a serious problem and here is some advice. I don't claim to be an expert or a veterinarian so take it for what it is.
You have not said anything about feeding a recovery diet such as critical care. If you have not been supplied with a recovery diet and have not been feeding this by syringe chances are your pet is starving and could be in very serious condition. So I'm going to assume this is the case just in case I don't hear back from you. If you have been feeding critical care according your vet's recommendations then I think it is more likely something else. That something else could be a number of chemical imbalances caused from not eating the right diet and could be caused by getting too much sugar (glucose imbalance) from treats which should never be given to a sick chinchilla. And it could a bad reaction to anesthesia which I know some chinchillas have had and have pulled out of and some do not.
Please do not keep your hopes up to high. Your pet is showing symptoms of actually dying at this point. If you have not been given such a recovery diet you may want to seek another veterinarian that is more competent.
Most veterinarians are not trained well when it comes to small animals like guinea pigs or chinchillas and finding an experienced vet is usually very difficult. These animals have very sensitive digestive systems that can be easily disrupted by antibiotics because they rely on a healthy microbial culture inside of the stomach and intestines that is killed off by medication. To get it back the intestines need to be flowing as regularly as possible. Dosing of antibiotics has to be very precise as well and administration of antibiotics and food should be as evenly spaced as possible. Never give antibiotics on an empty stomach.
Another thing to consider is that treats, especially if they are sugary, cause gas to build up in the bowels causing an obstruction and if bad enough can cause fatal damage. Avoid giving a sick chinchilla anything but hay, pellets, or a diet formulated for recovering herbivores.
Because you don't have access to a recovery diet you should mush up some pellets in water, maybe a tablespoon's worth, and see if your pet will eat it. If it does not eat when food is put into its mouth it's probably too late to save it and it will need intensive emergency veterinary care immediately if there is any hope. I doubt you have 2 days. You are probably dealing with starvation at this point. If there has been no fecal output in the last 24-48 hours you are dealing gastrointestinal stasis which goes along with that and you should try to find an emergency clinic to manage it because it probably will not reverse itself without treatment.
Antibiotics and pain can cause issues with digestion in addition to not eating from the original malocclusion. Improper diet can result in anorexia. Anorexia can cause some of these symptoms. Gas can also be an issue and simethecone (An over the counter medication used for gas in infants) is the preferred measure. Add a couple of drops to the food for each feeding to help with this. Malocclusion itself is usually permanent and will require regular filings of the teeth. Some owners will opt to have their pets euthanized once a diagnosis of malo has been made. I did this with my first chinchilla but depending on the cause and the amount of root elongation the malo can sometimes be managed for several years. My recommendation, if you really want to save your pet and can, is to take it to an emergency clinic today and get it put on intensive care. Second best is see if you can some food down and if that may resolve a glucose issue. Obtain critical care and dosing instructions today if possible.
Again I am sorry I don't better news for you. I hope it will work out regardless. Sometimes it does but usually when a pet is this far gone it takes a lot of work to get it out of trouble.
