Allergy, Nose & Sinus

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

February 10, 2020
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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.



Chronic Sinus Infection

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.



Sinusitis from tooth infection

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.



Sinus Infection

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.



Maxillary Sinus

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.

    When Should You See an ENT Specialist in Singapore?

    • Any ear, nose or throat symptoms that you are troubled with or concerned about
    • Persistent blocked nose with mouth breathing or snoring

    Dr Gan Eng Cern

    Dr Gan Eng Cern is a distinguished ENT doctor with fellowship training. In addition to his clinical practice as an ear, nose and throat specialist in Singapore, Dr. Gan has contributed to the academic field as a Senior Clinical Lecturer at the Yong Loo Lin School of Medicine, National University of Singapore. He is recognised for his extensive research work, with numerous contributions to reputable international ENT journals. Dr Gan is also highly sought after as a speaker and has shared his surgical knowledge as a surgical dissection teacher at various prominent ENT conferences and courses.


    • 2020 – Reader’s Choice Gold Award for Best ENT Specialist (Expat Living Singapore)
    • 2016 – Best Educator Award (Eastern Health Alliance)
    • 2016 – “Wow” Award (Patient Compliment)
    • 2014 – Eastern Health Alliance Caring Award – Silver
    • 2014 – 19th Yahya Cohen Memorial Lectureship (awarded by the College of Surgeons, Academy of Medicine Singapore for best scientific surgical paper)
    • 2012 – Human Manpower Development Award (Ministry of Health, Singapore)
    • 2007 – Singhealth Best Doctor Award


    • MBBS – Bachelor of Science, Bachelor of Medicine, Bachelor of Surgery (University of New South Wales, Sydney, Australia)
    • MRCS (Edin) – Member of the Royal College of Surgeons Edinburgh, United Kingdom
    • MMed (ORL) – Master of Medicine in ENT (National University of Singapore)
    • FAMS – Fellow of the Academy of Medicine Singapore

    Why Choose Dr Gan Eng Cern


    Reliable & Reputable ENT Expert

    Experienced and patient ENT Specialist who has your best interests at heart. We aim to provide you with accessible and specialized care for any ENT condition in a comfortable setting.


    Friendly & Helpful Clinic Staff

    Our friendly staff will assist you to the best of our ability and we are happy to accept most insurance providers and assist with E-filing with relevant insurance providers or Medisave.


    Advanced ENT Equipment & Fully Equipped Facility

    Our ENT Specialist, Dr Gan Eng Cern, will be able to diagnose and offer personalised treatments for your specific ENT condition. You can expect a high level of ENT care in a spacious setting with in-house minor surgical, endoscopy, allergy testing and microscopy services.


    Financial Options

    There are various financial options available for you to ensure that you are able to receive the most optimal treatment and care. Our ENT clinic staff will be able to assist you with your medical insurance claims and work with your chosen healthcare organization to minimize the hassle and paperwork required. In some cases, you may be able to utilise the funds in your Medisave account to defray part of the costs of your treatment. As our clinic is accredited by the Medisave board, we are able to process your claims from your Medisave for certain clinic procedures.

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