11. Maxillary Sinus

Question 1

What are the four facial sinuses ?

Answer 1

Frontal.
Sphenoid.
Ethmoid.
Maxillary.

Question 2

Embryology - when does the sinuses begin to form ?

Answer 2

3-4th foetal months

Question 3

Embryology - what two sinuses are large at birth ?

Answer 3

Maxillary and ethmoid.

Question 4

Embryology - what sinuses undergo expansion in first few years of life ?

Answer 4

Sphenoid and frontal.

Question 5

Name the three functions of paranasal sinuses.

Answer 5

Resonance of voice.
Reserve chambers for warming inspired air.
Reduce weight of the skull.

Question 6

What is the largest sinus ?

Answer 6

Maxillary.

Question 7

What is the average volumetric space of the maxillary sinus in average adult ?

Answer 7

15ml.

Question 8

What is the average dimensions of the maxillary sinus ?

Answer 8

37mm high.
27mm wide.
35mm antero-posteriorly.
Pyramidal shaped cavity.

Question 9

Where does the maxillary sinus drain to ?

Answer 9

Middle meatus.

Question 10

Where is the middle meatus located ?

Answer 10

Superiorly on medial wall of maxillary sinus.

Question 11

Where are the alveolar canals which transport the posterior superior alveolar vessels and nerves to maxillary posterior teeth found ?

Answer 11

Posterior wall of sinus cavity.

Question 12

What epithelium lines the sinus ?

Answer 12

Pseudostratified ciliated columnar epithelium.

Question 13

What is the function of cilia ?

Answer 13

Mobilise trapped particulate matter and foreign material within the sinus.
Move this material toward the ostia for elimination into the nasal cavity.

Question 14

How would you manage a small OAC ?

Answer 14

Inform the patient.
If small - encourage clot, or suture margins, prescribe antibiotics, give post-op instructions to minimise pressure forming within the sinuses.

Question 15

What size of OAC will usually heal with a normal blood clot formation and routine mucosal healing ?

Answer 15

<2mm.

Question 16

How would you manage a large OAC ?

Answer 16

Close with buccal advancement flap (3 sided).

Question 17

What are the signs/symptoms of chronic OAF ?

Answer 17

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.

Question 17

What type of sutures would you use on primary closure of OAC, why and how long would you leave them in for ?

Answer 17

Silk sutures.
Want stitches to be held in place for longer.
2 weeks (rather than 1).

Question 17

What type of flap should be raised to close sinus tract ?

Answer 17

Buccal advancement flap.

Question 18

What teeth are more likely to result in fracture of maxillary tuberosity ?

Answer 18

Single standing molar teeth with splayed roots.

Question 18

Why does the surgical procedure for closure of chronic OAC differ from acute OAC ?

Answer 18

Fistula must be removed (epithelial lining) prior to performing 3-sided buccal advancement flap.

Question 19

What are some signs of fractured tuberosity ?

Answer 19

Noise.
Movement visually or with supporting fingers.
Move than one tooth movement.
Tear in soft tissue of palate.

Question 19

What are 5 things to remember if you choose to splint tooth after alveolar tuberosity fracture ?

Answer 19

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.

Question 20

What precipitates sinusitis ?

Answer 20

Viral infection.

Question 21

What is sinusitis ?

Answer 21

Inflammation.
Obstruction of ostia.
Trapping of debris in cavity.

Question 22

What might alter mucociliary clearance patterns ?

Answer 22

Allergens, inflammation, anatomic abnormalities, OAC.

Question 23

What are the signs/symptoms of sinusitis ?

Answer 23

Facial pain, pressure, congestion, nasal obstruction, paranasal drainage, hyposmia, fever, headache, dental pain, halitosis, fatigue, cough, ear pain (referred pain), anaesthesia/paraesthesia over cheek.

Question 24

What are common dental causes which sinusitis can be confused with ?

Answer 24

PA abscess, periodontal infection, deep caries, recent extraction socket, TMD, neuralgia or atypical facial pain.

Question 25

What are indicators on examination of sinusitis ?

Answer 25

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.

Question 26

What decongestant can be prescribed for sinusitis symptomatic treatment ?

Answer 26

Ephedrine nasal drops 0.5% one drop for each nostril 3x daily when required for maximum 7 days.

Question 27

What is the risk of recurrent use of decongestants ?

Answer 27

Atrophy of lining of antrum.

Question 28

When should antibiotics be prescribed for sinusitis ?

Answer 28

Only when symptomatic treatment is not effective or symptoms worsen and signs/symptoms point to a bacterial sinusitis.

Question 29

What two antibiotics can be prescribed for sinusitis ?

Answer 29

Amoxicillin or doxycycline.

Question 30

What dose of amoxicillin should be prescribed for sinusitis ?

Answer 30

500mg 3x daily for 7 days - SDCEP.

Question 31

What dose of doxycycline should be prescribed for sinusitis ?

Answer 31

100mg x1 daily for 7 days (double loading dose - on first day) - SDCEP.