OS - maxillary sinuses

Question 1

what roots of what teeth are most commonly found in maxillary sinuses?

Answer 1

palatal roots of maxillary molars

Question 2

what are maxillary sinus peri-operative complications?

Answer 2

endodontic materials or instruments intruded in to the sinus

Question 3

why may pts think sinus pathology is toothache?

Answer 3

the trigeminal nerve (maxillary division) innervates the teeth and sinus

Question 4

what can sinus pathology present as inside the mouth?

Answer 4

cancer
erosion of the bone in the mouth
a cyst in the antrum can displace teeth and cause communication in to oral cavity

Question 5

what are the paranasal sinuses lined by and what does this produce?

Answer 5

ciliated epithelium (respiratory epithelium) - produces mucous

Question 6

what are the paranasal sinuses?

Answer 6

air-containing sacs lined by ciliated epithelium communicating with the nasal cavity

Question 7

what are the 4 paranasal sinuses?

Answer 7

bilateral frontal, ethmoid, sphenoid, and maxillary

Question 8

what is the cause of pan sinusitis?

Answer 8

infection in one sinus that is in close proximity to the draining ostium

Question 9

what are the said physiological functions of the paranasal sinuses?

Answer 9

humidification of air
filtering air
production of voice
lightening the weight of the head
crumple zone (protects force on the face to brain)

Question 10

what do the ethmoid sinuses look like radiographically?

Answer 10

small air cells

Question 11

where does the sphenoid sinus lie?

Answer 11

under sella turcica

Question 12

are the frontal sinuses symmetrical?

Answer 12

no

Question 13

why do sinuses present as black on a CT scan?

Answer 13

air filled

Question 14

how are secretions drained from the maxillary sinus?

Answer 14

against gravity - ciliated epithelium beat in a spiraling pattern to ostium

Question 15

what is the maxillary sinus also known as?

Answer 15

the antrum of highmore

Question 16

what shape is the maxillary sinus and how much volume does it hold?

Answer 16

pyramidal shape, volume of 15-30mls

Question 17

when does the maxillary sinus start to develop?

Answer 17

3 months IUL

Question 18

what size is the maxillary sinus by the age of 9?

Answer 18

60% of its max size

Question 19

when does maxillary sinus become its full size?

Answer 19

18 years

Question 20

what issues arises with the continuous growth of the maxillary sinus throughout life?

Answer 20

more likely to cause OAC and fracture tuberosities

Question 21

what anatomical features are related to the maxillary sinus?

Answer 21

orbit
infra-orbital nerve
nasolacrimal duct
posterior teeth
lateral wall of the nose
pterygopalatine fossa
maxillary artery

Question 22

what is Schneiderian membrane?

Answer 22

respiratory epithelium that lines the sulcus

Question 23

where do all paranasal sinuses drain through?

Answer 23

lateral wall of the nasal cavity

Question 24

where does the maxillary sinus drain to?

Answer 24

middle meatus through a 2.4mm diameter ostium (2/3rds up the medial wall of the sinus)

Question 25

where does the frontal sinus drain to, what innervates it, and what supplies its blood?

Answer 25

drains to: middle meatus innervated by: supraorbital nerve blood supply: anterior ethmoidal arteries

Question 26

where does the sphenoid sinus drain to, what innervates it, and what supplies its blood?

Answer 26

drains to: sphenoethmoidal recess innervated by: posterior ethmoidal nerve blood supply: pharyngeal branch of maxillary artery

Question 27

where does the ethmoidal air cells (ant, post, middle) drain to, what innervates it, and what supplies its blood?

Answer 27

anterior - drains to middle meatus middle - drains to lateral wall of middle meatus posterior - drains to lateral wall of superior meatus innervated by: maxillary nerves blood supply: maxillary artery

Question 28

what can infection in the frontal sinuses co-infect?

Answer 28

maxillary and ethmoidal sinuses (pan sinusitis)

Question 29

what is the physiological role of the maxillary sinus thought to be?

Answer 29

immunological defense

Question 30

how can you investigate the maxillary sinus?

Answer 30

CT/MRI endoscopy - more commonly used for antral pathology antral tap (in the past) - small hole for drainage transillumination - if illuminates = healthy

Question 31

what sinuses can be investigated through transillumination?

Answer 31

frontal and maxillary

Question 32

why is the maxillary sinus of significance to dentistry?

Answer 32

roots of the upper molars/ premolars closely related to the antrum and share common innervation dental procedures complicated by problems involving the antrum - OAC, roots in antrum, fracture tuberosity, extruded root canal materials

Question 33

what is antral lining prolapse?

Answer 33

lining of the antrum stays intact but prolapses down

Question 34

what is common pathology associated with the maxillary sinuses?

Answer 34

infective sinusitis-bacterial, viral, fungal, 10% dental origin, OAF fractures tumours/cysts

Question 35

what causes non-infective sinusitis?

Answer 35

allergic, vasomotor, septal deviation, foreign body

Question 36

what causes acute infective sinusitis?

Answer 36

bacterial infection which follows viral infection caused by strep. pneumoniae, H. influenzae (resp bacteria)

Question 37

how do you diagnose acute infective sinusitis?

Answer 37

clinical grounds only

Question 38

what history will a pt present with with acute infective sinusitis?

Answer 38

pain tenderness across area worsens on bending over no swelling posterior teeth TTP post nasal drip mucopurulent discharge poor response to nasal decongestants

Question 39

how do you manage acute sinusitis in fit and healthy pts?

Answer 39

menthol inhalation

Question 40

how do you manage acute infective sinusitis in pts with prolonged severe infection/ underlying immunocompromisation?

Answer 40

amoxicillin 500mg TDS for 7 days OR doxycycline 100mg (200mg first day) for 7 days.

Question 41

how does inhalation manage sinusitis?

Answer 41

shrinks linings and opens ostium, allowing contents to discharge through ostium in to lateral wall of nose, nasopharynx then oropharynx

Question 42

how does sinusitis become self limiting?

Answer 42

mucopurulent out of mucous

Question 43

why is amoxicillin not prescribed for sinusitis anymore?

Answer 43

due to its widespread use during covid

Question 44

what can mechanically obstruct sinuses causing sinusitis?

Answer 44

oedema of nasal mucosa polyps septal deviation

Question 45

what can result in impaired mucus clearance?

Answer 45

poor ciliary action abnormally thick or sticky mucous (cystic fibrosis)

Question 46

how does chronic sinusitis present?

Answer 46

ongoing low-grade symptoms

Question 47

management of chronic sinusitis?

Answer 47

antral lavage intranasal antrostomy metronidazole with amoxycillin/ erythromycin

Question 48

what is an oral antral fistula?

Answer 48

persistent epithelial lined tract (must be excised)

Question 49

what does chronic sinusitis suggest in the absence of OAF?

Answer 49

immunocompromise

Question 50

what is an antral mucocoele?

Answer 50

intra antral pathology - cyst formed in antral lining of schneiderian membrane

Question 51

what can an antral mucocoele lead to?

Answer 51

chronic sinusitis if it gets too big that it obstructs

Question 52

what are 3 complications of sinusitis?

Answer 52

brain abscesses orbital cellulitis cavernous sinus thrombosis

Question 53

what are the causes of OAC?

Answer 53

extraction of posterior teeth tuberosity fracture middle third fracture malignancy/ pathology

Question 54

what are symptoms of an OAC?

Answer 54

passage of fluid down nose passage of air into mouth alteration of voice unilateral epistaxis or nasal obstruction

Question 55

what can an untreated fistula cause?

Answer 55

persistent sinusitis unilateral nasal discharge intra-oral antral polyp cacogeusia and facial pain

Question 56

OAC management?

Answer 56

ideally close immediately - buccal advancement flap plate or modified denture antibiotics, ephedrine drops, mucolytic inhalations avoid nose blowing

Question 57

what size of OAC can close spontaneously?

Answer 57

less than 5mm

Question 58

where does maxillary sinus drain?

Answer 58

middle meatus through an ostium 2/3rds up the medial wall of sinus

Question 59

what innervates the maxillary sinus?

Answer 59

second branch of trigeminal - maxillary nerve