Maxillary Sinus Flashcards
When does formation of the maxillary sinus begin in utero?
3/4 foetal months
What sinuses are relatively large and well formed at birth? (2)
maxillary
ethmoid
What are the functions of the paranasal sinuses? (3)
- Resonance to the voice
- Reserve chambers for warming inspired air
- Reduce the weight of the skull
What is the average volumetric space of an adult maxillary sinus?
15ml
What are the average dimensions of the maxillary sinus? (3)
- 37mm high
- 27mm wide
- 35mm antero-posteriorly
Where is the opening of the maxillary sinus located?
Middle meatus (hiatus semilunaris)
superiorly on medial wall of sinus
What length is the opening to the maxillary sinus?
4mm
Where is the alveolar canal that transports the posterior superior alveolar nerve located in relation to the sinus?
generally found on the posterior wall of the sinus cavity
What epithelium lines the maxillary sinus?
pseudostratified ciliated columnar epithelium
What is the function of the cilia that lines the sinus? (2)
mobilise trapped particulate matter and foreign material within the sinus
move this material toward the ostia for elimination into the nasal cavity
What complications are associated with the maxillary sinus? (6)
- Oro-Antral Communication (OAC) = Acute
- Oro-Antral Fistula (OAF) = Chronic
- Root in the antrum (iatrogenic)
- Sinusitis
- Benign Lesions
- Malignant Lesions
How do we diagnose an oro-antral communication? (8)
- can predict by the Size of tooth/roots
- predict via the radiographic position of roots in relation to antrum during pre-op assessment
- Bone at trifurcation of roots of removal
- Bubbling of blood post extraction
- Nose holding test
- Direct vision
- Good light and suction (suction can sometimes create an echo)
- Blunt probe (take care not to create an OAC) = X don’t use
Define a fistula.
epithelial lines tract
How do we manage a small OAC/OAC with sinus lining intact? (5)
- Inform patient
- Encourage clot
- Suture margins to hold clot in place
- Antibiotic (area of debate)
- Post-op instructions
= Minimising pressure formation within the sinuses and mouth
Avoid nose blowing, sucking a straw, inflating balloons, smoking, singing.
How do we manage a large OAC? (6)
Inform patient
create a buccal advancement flap
possible trimming of buccal bone
incise the periosteum
ensure the BAF closes the communication with NO tension
suture and close BAF.
What post-op instructions do we provide after and OAC? (1)
Minimising pressure formation within the sinuses and mouth;
Avoid nose blowing, sucking a straw, inflating balloons, smoking, singing.
What do patients complain of if they have a chronic OAF? (6)
(Hx of upper extraction)
- Problems with fluid consumption = fluids from nose
- Problems with speech or singing (nasal quality)
- Problems playing brass/wind instruments
- Problems smoking cigarettes or using a straw
- Bad taste/odour/halitosis/pus discharge (post-nasal drip)
- Pain/sinusitis type symptoms
How do we treat a chronic OAF? (4)
Remove the tract
Raise a flap
washout the antrum
close the flap
What types of flaps can we use to close OAF/C? (4)
- Buccal Advancement Flap
- Buccal Fat Pad with Buccal Advancement Flap
- Palatal Flap = thicke tissue
- Bone Graft/Collagen Membrane
What is the advnatge of a buccal fat pad buccal advancement flap?
it is a reinforced/thicker flap
What are the disadvantages of using a buccal fat pad advancement flap? (2)
- More bruising/swelling
- Can cause asymmetry (one side more boney looking)
What can cause fracture of the maxillary tuberosity? (5)
- XLA of Single standing molar
- Unknown unerupted molar or wisdom tooth
- Pathological gemination/concrescence
- Extracting in wrong order (start from back to front)
- Inadequate alveolar support
How do we diagnose/identify a fractured maxillary tuberosity? (4)
- Noise “cracking”
- Movement noted both visually or with supporting fingers
- More than one tooth movement
- Tear in soft tissue of palate
How do we manage a fractured maxillary tuberosity? (2)
If noticed early enough;
* Reduce the section and stabilise the bone and teeth by splinting
or
If not noticed early and the blood supply has been lost;
* Dissect out the bone and the tooth and close the wound primarily – no BAF needed
What can we use to splint teeth/bone after a maxillary tuberosity fracture? (3)
- Orthodontic buccal arch wire with composite
- 8-12 weeks with rigid HSSW and composite
- Arch bar
If a tooth is splinted after a maxillary tuberosity fracture, what must we do next? (5)
- Dissect out the tooth or treat the pulp = ensure no symptoms
- Ensure it is out of occlusion by reducing the occlusal height (once oedema occurs = no occlusal interference)
- Consider antibiotic and antiseptics
- Provide post-op instructions
- If tooth not dissected out, Remove the tooth surgically 4-8 weeks later
If there are roots/teeth in the antrum why must we take a CBCT on the day of surgery and not before?
roots/teeth can travel
What options do we have for root/teeth retrieval from the maxillary antrum? (3)
OAF-type approach / through the extraction socket
Caldwell-Luc approach:
- Access via Buccal/Labial sulcus
- Buccal window cut in bone more anteriorly (premolar region)
- ENT = Endoscopic Retrieval
What causes sinusitis? (3)
(Most are precipitated by the effects of a viral infection)
Inflammation and oedema = Obstruction of ostia
= Trapping of debris within sinus cavity
Alteration of mucociliary clearance patterns by:
- Allergens
- Inflammation
- anatomic abnormalities
Normal physiological function is disrupted by the cellular damage that occurs to the mucosal lining = this affects normal ciliary function
What can occur when the maxillary sinus cannot evacuate its contents and there is a build up of pressure?
opportune situation for bacterial overgrowth of normal flora
(bacterial infection)
What are the three main characteristics signs and symptoms of sinusitis?
Discomfort on palpation of infraorbital region - bilateral or unilateral
A diffuse pain in the maxillary teeth
- Equal sensitivity from percussion of multiple teeth in the same region
Pain that worsens with head or facial movements – ask to jump/swing head up and down
What are general signs and symptoms associated with sinusitis? (14)
- Facial pain
- Pressure
- Congestion (fullness)
- Nasal obstruction
- Paranasal drainage
- Hyposmia
- Fever
- Headache
- Dental pain
- Halitosis
- Fatigue
- Cough
- Ear pain
*Anaesthesia/paraesthesia over cheek
What other diagnosis should we rule out before diagnosing sinusitis? (6)
- Periapical abscess
- Periodontal infection
- Deep caries
- Recent extraction socket
- TMD
- Neuralgia or atypical facial pain / chronic midfacial pain
How do we manage sinusitis? (5)
Treat presenting symptoms
- Reduce tissue oedema
- Decongestants to reduce mucosal oedema
Ephedrine nasal drops 0.5% one drop each nostril up to three times daily when required - Reverse obstruction of the ostia
- Humidified air is also helpful (steam/menthol inhalations)
Why can we only prescribe Ephedrine for up to 7 days?
it can cause atrophy to the nasal lining
When should we prescribe antibiotics for sinusitis? (2)
Antibiotics should only be used if symptomatic treatment is not effective/symptoms worsen
AND
signs and symptoms point to a bacterial sinusitis
What antibiotics do we prescribe for bacterial sinusitis? (2)
Pen V tablets 250mg, 2x tablets 4x times a day
8 tablets for 5 days
or
Doxycycline capsules 100mg, once a day, for 7 days (initial 200mg loading dose = 2x tablets)
What is a non-resolving sinusitis usually caused by?
What can a non-resolving sinusitis lead to?
fungal sinusitis
- can cause expansion of the bony walls by increased mucus secretion and fungal growth
What can cause a traumatic sinusitis? (9)
- Sinus wall fractures
- Orbital floor fractures
- Root canal therapy
- Tooth extractions
- Dental Implants / Sinus lifts
- Deep periodontal treatment
- Nasal packing
- Nasogastric tubes
- Mechanical (nasal) intubation
What other factors can contribute to sinusitis? provide examples (3)
- Benign sinus lesions
e.g. polyps, papillomas, antral pseudocysts, mucoceles and mucous retention cysts - Odontogenic cysts / odontogenic tumours expanding into the maxillary sinus
- Malignant lesions (rare)
- Primary tumours of bone or epithelial sinus lining
- Local spread from adjacent sites
