11. Maxillary Sinus Flashcards
What are the four facial sinuses ?
Frontal.
Sphenoid.
Ethmoid.
Maxillary.
Embryology - when does the sinuses begin to form ?
3-4th foetal months
Embryology - what two sinuses are large at birth ?
Maxillary and ethmoid.
Embryology - what sinuses undergo expansion in first few years of life ?
Sphenoid and frontal.
Name the three functions of paranasal sinuses.
Resonance of voice.
Reserve chambers for warming inspired air.
Reduce weight of the skull.
What is the largest sinus ?
Maxillary.
What is the average volumetric space of the maxillary sinus in average adult ?
15ml.
What is the average dimensions of the maxillary sinus ?
37mm high.
27mm wide.
35mm antero-posteriorly.
Pyramidal shaped cavity.
Where does the maxillary sinus drain to ?
Middle meatus.
Where is the middle meatus located ?
Superiorly on medial wall of maxillary sinus.
Where are the alveolar canals which transport the posterior superior alveolar vessels and nerves to maxillary posterior teeth found ?
Posterior wall of sinus cavity.
What epithelium lines the sinus ?
Pseudostratified ciliated columnar epithelium.
What is the function of cilia ?
Mobilise trapped particulate matter and foreign material within the sinus.
Move this material toward the ostia for elimination into the nasal cavity.
How would you manage a small OAC ?
Inform the patient.
If small - encourage clot, or suture margins, prescribe antibiotics, give post-op instructions to minimise pressure forming within the sinuses.
What size of OAC will usually heal with a normal blood clot formation and routine mucosal healing ?
<2mm.
How would you manage a large OAC ?
Close with buccal advancement flap (3 sided).
What are the signs/symptoms of chronic OAF ?
Problems with fluid consumption - fluids from nose.
Problems with speech or singing - nasal quality.
Problems playing brass/wind instruments.
Problems smoking or using straw.
Bad taste/odour/halitosis/pus discharge.
Pain/sinusitis.
What type of sutures would you use on primary closure of OAC, why and how long would you leave them in for ?
Silk sutures.
Want stitches to be held in place for longer.
2 weeks (rather than 1).
What type of flap should be raised to close sinus tract ?
Buccal advancement flap.
What teeth are more likely to result in fracture of maxillary tuberosity ?
Single standing molar teeth with splayed roots.
Why does the surgical procedure for closure of chronic OAC differ from acute OAC ?
Fistula must be removed (epithelial lining) prior to performing 3-sided buccal advancement flap.
What are some signs of fractured tuberosity ?
Noise.
Movement visually or with supporting fingers.
Move than one tooth movement.
Tear in soft tissue of palate.
What are 5 things to remember if you choose to splint tooth after alveolar tuberosity fracture ?
Remove or treat the pulp.
Ensure it is out of occlusion.
Consider antibiotics and antiseptics.
Post-op instructions.
Remove the tooth surgically 4-8 weeks later - to avoid 2nd fracture.
What precipitates sinusitis ?
Viral infection.
What is sinusitis ?
Inflammation.
Obstruction of ostia.
Trapping of debris in cavity.
What might alter mucociliary clearance patterns ?
Allergens, inflammation, anatomic abnormalities, OAC.
What are the signs/symptoms of sinusitis ?
Facial pain, pressure, congestion, nasal obstruction, paranasal drainage, hyposmia, fever, headache, dental pain, halitosis, fatigue, cough, ear pain (referred pain), anaesthesia/paraesthesia over cheek.
What are common dental causes which sinusitis can be confused with ?
PA abscess, periodontal infection, deep caries, recent extraction socket, TMD, neuralgia or atypical facial pain.
What are indicators on examination of sinusitis ?
Discomfort on palpation of infraorbital region.
Diffuse pain in maxillary teeth.
Equal sensitivity from percussion of multiple teeth in same region.
Pain that worsens with head or facial movement.
What decongestant can be prescribed for sinusitis symptomatic treatment ?
Ephedrine nasal drops 0.5% one drop for each nostril 3x daily when required for maximum 7 days.
What is the risk of recurrent use of decongestants ?
Atrophy of lining of antrum.
When should antibiotics be prescribed for sinusitis ?
Only when symptomatic treatment is not effective or symptoms worsen and signs/symptoms point to a bacterial sinusitis.
What two antibiotics can be prescribed for sinusitis ?
Amoxicillin or doxycycline.
What dose of amoxicillin should be prescribed for sinusitis ?
500mg 3x daily for 7 days - SDCEP.
What dose of doxycycline should be prescribed for sinusitis ?
100mg x1 daily for 7 days (double loading dose - on first day) - SDCEP.
