Sinusitus After Wisdom Teeth Removal
It is not widely appreciated, but the finding of sinusitus after having wisdom teeth extracted could pose a dillema. As described on the homepage of teethremoval.com after this website's owner had a 24/7 headache from having his wisdom teeth extracted he had a brain MRI performed. The only finding was that the right maxillary sinus was completely filled with fluid. Thus it was postulated that the sinus membrane could have been torn during extraction; however, no other symptoms warranted this observation. This lead to subsequent antibiotics for several months and later sinus surgery.
It is well known that dental procedures such as a wisdom tooth extraction or even a root canal can perforate the maxillary sinus. Often patients will describe some sudden huge rush or gush of fluid being observed coming from the nostril or even going into the mouth which smells bad. Some cases may not be so cut and dry so a follow up x-ray, CT scan, or MRI done if there are noticeable annoying symptoms after having a wisdom tooth extracted could show fluid in the maxillary sinus. [1, 2]
However, this is actually a very normal finding. In the book Overdiagnosed: Making People Sick in the Pursuit of Health by H. Gilbert Welch and et al. he discusses how when he first started as a doctor he would see a lot of patients who complained of sinus pain. He would order x-rays and often the radiologist would say sinusitis was present. H. Gilbert Welch was suspicious and did not think all these patients really had sinusitis. He ordered an x-ray for himself to test his theory. Low and behold the radiologist said there was "an ovid density involving the inferior margin of the left maxillary sinus... This may well represent a polyp secondary to chronic maxillary sinusitis. " H. Gilbert Welch had no symptoms and no sinus problems. 
A study in the New England Journal of Medicine performed CT scans of 31 healthy adults with a common cold to see if they also had sinusitis. 27 of the 31 adults had abnormalities of one or both maxillary sinuses which consisted of radiopaque material in the sinus cavity which is interpreted as mucosal swelling (inflammation). 
Some people who have wisdom teeth extracted (such as for preventative reasons) will have no symptoms and be completely healthy prior to surgery. However, it is possible that after having their wisdom teeth removed they could have symptoms. This may cause a subsequent x-ray, CT scan, and/or MRI to look for abnormalities. The problem thus is when it comes to sinusitus in particular is whether or not the abnormality was present prior to surgery or if it happened as a result of surgery and thus is a likely cause of the current symptoms. For this reason, it may be beneficial to have a baseline scan done prior to having any wisdom tooth extracted. This is somewhat controversial, but is likely best suited with an x-ray or MRI scan of the brain. (A CT scan emmits more radiation so is likely not as useful for a baseline study). Having an imaging study performed prior to surgery will allow one to determine more clearly what may have happened as a result of surgery if symptoms develop and additional care is needed. Since the maxillary sinus is present on both the left and right side but only near the upper wisdom teeth this only applies to the upper left and right wisdom teeth which may be extracted, not the lower wisdom teeth.
1) Anna Zairi and Theodoros Lambrianidis. Accidental Extrusion of Sodium Hypocholorite into the Maxillary Sinus. Quintessence International. 39. pages 745 - 748. 2008.
Mark Burhenne DDS. Sinus Drainage and Pain After a Root Canal Procedure. July 28, 2010. http://askthedentist.com/sinus-drainage-and-pain-after-a-root-canal-procedure/Accessed May 23, 2011.
3. H. Gilbert Welch, Lisa M. Schwartz, and Steven Woloshin. Overdiagnosed: Making People Sick in the Pursuit of Health. Beacon Press. 2011.
4) Jack M. Gwaltney. Computed Tomographic Study of the Common Cold. New England Journal of Medicine. vol. 330. no. 1. pages 25-30. 1994.