Allergy, Nose & Sinus

Sinusitis from a tooth infection (WARNING – GRAPHIC MEDICAL IMAGES)

February 10, 2020

Dr Gan recently saw a patient, Mr A, who complained of left cheek pressure and fullness over the last one year. This was associated with a left blocked nose and postnasal drip (mucous dripping down the back of the nose). He has visited a few doctors and had four courses of oral antibiotics. The symptoms did improve with antibiotics and nasal douche (nose wash with salt water) but they never resolve completely.


Dr Gan performed a nasoendoscopy (scope through the nose) on Mr A. It showed a congested left sinus outflow track with an inflammatory polyp. Mucopus (mixture of mucous and pus) can be seen flowing from the sinus to the back of his nose and throat (resulting in postnasal drip). The rest of his ENT and head & neck examination was unremarkable.



A nasoendoscopic view of the left nose showing an inflammatory polyp



A nasoendoscopic view of the back of the left nose showing mucopus from the obstructed sinus outflow track



Based on the clinical history and nasoendoscopy findings, Mr A was diagnosed with chronic sinusitis (sinus infection). A sample of the mucopus from Mr A’s nose was taken for culture (sent to the lab to grow the bacteria for antibiotic sensitivity). Given the chronicity of his symptoms, Mr A was advised to undergo a CT scan (special series of X-rays) of his nose and sinuses to investigate the cause of his persistent or refractory sinusitis. However, Mr A was not keen and would like to be more conservative in his treatment.


As M A’s previous courses of antibiotics ranged from 5-7 days. The duration of treatment may have been inadequate for his sinus infection. Hence, Mr A was given a two weeks course of “strong” antibiotics along with nasal douche and nasal steroid sprays. Upon review in the clinic 2 weeks later, Mr A’s symptoms improved, but again still persistent and troubling to him. The culture from the nose did not show any bacterial growth. Mr A was left with limited options and agreed to undergo a CT scan of his nose and sinuses. The scan showed that his left cheek sinus (maxillary sinus) was completely filled with mucopus. It also showed that his left upper molar tooth has a dental cyst that has ruptured into the maxillary sinus.



A CT scan of the nose & sinus showing a completely blocked and infected left maxillary sinus. There was also a left upper rear tooth (molar) with a cyst that has ruptured into the maxillary sinus



Mr A denied any toothaches but did complain of some sensitivity in his gums. He was referred to a dental surgeon who confirmed that the left upper molar dental cyst was infected. Hence, the protruded upper molar in the sinus was likely the source of Mr A’s recalcitrant left maxillary sinus infection. Mr A underwent left functional endoscopic sinus surgery (aka FESS or sinus surgery), extraction of the left upper molar/dental cyst and closure of the dental wound.


During surgery, there was copious amount of pus seen in the left maxillary sinus. This was flushed out completely. Immediately post surgery, Mr A felt the relieve from the pressure in his left cheek. Mr A was last seen about a month after surgery. His nose symptoms and pressure in the left cheek have completely resolved.



An endoscopic view of the opening of the left maxillary sinus in the nose during surgery. The scope is a 30 degrees scope looking out 30 degrees to the side.



After the pus was suctioned out, the back wall and floor of the maxillary sinus can be seen. This is a view on a 30 degree scope (looking to the side)



The roots of the upper molars (upper rear teeth) are very close to the floor of the maxillary sinus. In some patients, their upper molars may protrude into the maxillary sinus. An infected tooth in the sinus may be a cause of sinus infection. It is important to remove the cause or source of the sinus infection or the sinus infection will never clear.

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