Maxillary Sinus Flashcards
What are the paranasal sinuses lined with
mucous membrane
What type of epithelium are paranasal sinuses lined with
pseudostratified ciliated columnar epithelium
What is the function of cilia
o Mobilise the trapped particular matter and foreign material withint he sinus
o Move this material towards the ostia for elimination into the nasal cavity
What is the function of the paranasal sinuses
o Lighten the skull bones
o Act as sound resonators
o Provide mucous for the nasal activity
o Reserve chambers for warming inspired air due to good blood supply
What are the 4 pairs of paranasal sinuses
maxillary
frontal
sphenoidal
ethmoidal
What shape is the maxillary sinus
pyramid
Where does the maxillary sinus drain
middle meatus
What part of the maxillary sinus anatomy promotes sinusitis
ostium of sinus is higher than the floor of the sinus cavity
What is the maxillary sinus opening to the middle meatus called
hiatus semilunaris
What does the posterior wall of the maxillary sinus contain
the alveolar canals that transport the posterior superior alveolar nerves and vessels to the maxillary posterior teeth
Describe the frontal sinuses
In frontal bone
Communicates with nasal cavity via frontonasal duct
Describe the sphenoidal sinuses
Located in sphenoid bone
Communicate with nasal cavity via opening superior to each superior nasal concha
Describe the ethmoidal sinuses
Aka ethmoid air cells
In the lateral mass of each ethmoid bone
Open into superior meatus and middle meatus
When are the sinuses formed
Formation occurs during 3rd and 4th foetal months with evaginations of the mucosa of the nasal cavity
What are the most common issues associated with the maxillary sinus
- OAC
- OAF
- root/tooth in antrum
- sinusitis
- benign lesions
- malignant lesions
How is an OAC created
by tooth removal resulting in creation of a communication due to bone breakage or tearing of the lining
What is diagnosis of OAC based on
- Size of tooth
- Radiographic position of roots in relation to antrum
- Bone at trifurcation of roots
- Bubbling at blood
- Nose holding test (careful as can create OAC)
- Direct vision
- Good lighting and suction, look out for an echo
- Blunt probe (can create OAC)
What radiographic signs may indicate a tooth of being mroe problematic
o Big splayed roots can be more problematic
o Low standing molars have increased chance of fractured tuberosity and OAC
What is management of OAC
inform px
depends on size
What is the management for a small OAC or if the lining is intact
o Encourage clot
o Suture margins
o Antibiotic (area of debate)
o Post-op instructions
What are the post-op instructions for OAC
Minimising pressure formation with the sinuses and mouth
What size of OAC usually heal with normal blood clot formation and routine mucosal healing
<2mm
If the OAC is large, how should it be managed
close with buccal advancement flap
What is the buccal advancement flap
broad based trapezoid flap with 2 relieving incisions which are less flared, flap should be lifted so bare bone exposed
Why may you trim buccal bone when doing a buccal advancement flap
to get flap to fit
Why may you incise the periosteum when doing a buccal advancement flap
If flap cant be stitched without tension then periosteum should be incised to loosen it
What makes an OAF different from OAC
OAF has epithelial lined tract
What may a px complain of for an OAF
- Problems with fluid consumption (coming out of nose)
- Problem with speech/singing (nasal quality)
- Problems playing brass/wind instruments (hard to create pressure)
- Problems smoking or using a straw
- Bad taste/odour/halitosis/pus discharge
- Pain/sinusitis type symptoms
What is the tx of OAF
same as OAC except epithelial lined tract should be exised prior
What are the flap design options for OAF
- BAF
- buccal fat pad with BAF
- palatal flap
- bone graft/collagen membrane
What should you do if you suspect a root in the maxillary antrum
- confirm via xray (OPT, occlusal, PA, CBCT)
How can the root/tooth be retrived from the antrum
- OAF type approach through extraction socket
- caldwell luc approach
- ENT
What is the OAF approach to getting the root/tooth out the antrum
o Open fenestration with care
o Suction using narrow bore
o Small curettes used
o Irrigation or ribbon gauze should be used
o Close as for OAC
What is the caldwell luc approach for getting the tooth/root out the antrum
o Buccal window cut in bone
When do you refer to ENT for root/tooth removal from antrum
o If unretrievable
o May do endoscopic retrieval
When examining a px with maxillary discomfort, what should you remember
- The close relationship of the sinuses and the posterior maxillary teeth
- The aetiology of paranasal sinus inflammation and infection
- Patients with sinusitis often present to the dentist first
What is the aetiology of sinusitis
- most precipiated by effects of a viral infection
- mucociliary clearance patterns may be altered
- normal physiological function is further disrupted
- sinus can no longer evacuate its contents efficiently
What are the effects precipiated by viral infection that results in sinusitis
o Inflammation and oedema
o Obstruction of ostia
o Trapping of debris within sinus cavity
What may the mucociliary clearance patterns be altered by
o Allergens
o Inflammation
o Anatomic abnormalities
When the sinus can no longer evacuate its contents efficiently, what does this result in
- build up of pressure
- opportunistic situation for bacterial overgrwoth of normal flora
What are signs/symptoms of sinusitis
- Facial pain
- Pressure
- Congestion
- Nasal obstruction
- Paranasal drainae
- Hyposmia
- Fever
- Headache
- Dental pain
- Halitosis
- Fatigure
- Cough
- Ear pain
- Anaesthesia
What causes should be ruled out with suspected sinusitis
- Periapical abscess
- Periodontal infection
- Deep caries
- Recent extraction socket
- TMD
- Neuralgia or atypical facial pain/chronic midfacial pain
What are indicators of sinusitis
- Discomfort on palpation of infraorbital region
- A diffuse pain in the maxillary teeth (all TTP)
- Equal sensitivity from percussion of multiple teeth in same region
- Paint that worsens with head or facial movements
What are tx aims of sinusitis
- Treat presenting symptoms
- Reduce tissue oedema
- Reverse obstruction of the ostia
What is tx of sinusitis
Decongestants reduce mucosal oedema
humified air
What do the decongestants consist of
Ephedrine nasal drops 0.5% one drop each nostril up to 3x daily when required (use for up to 7 days, otherwise can cause atrophy of nose lining)
When should AB be used
- Only used if symptomatic treatment not effective or symptoms worsen AND signs and symptoms point to a bacterial sinusitis (superinfection)
What is the AB regimen
o Amoxicillin 500mg TID 7 days (first line)
o Doxycycline 100mg once a day for 7 day, 8 tablets given as 200mg loading dose (first day)
How can trauma result in sinusitis
by violating the integrity of the bony cavity and sinus membrane
What are the effects of trauma on the sinus
o Sinus wall fractures
o Orbital floor fractures
o Root canal therapy
o Tooth extractions
o Dental implants/sinus lift
o Deep periodontal treatment
o Nasal packing
o Nasogastric tubes
o Mechanical (nasal) intubation
What are benign lesions of the sinus
Polyps, papilloma, antral pseudocysts, mucoceles, mucous retention cysts
Odontogenic cysts/odontogenic tumours expanding into maxillary sinus
What are malignant lesions of the sinus
Primary tumours
Local spread from adjacent sites
What is the aetiology of maxillary tuberosity fracture
o Single standing molar (thin bone)
o Unknown unerupted molar or wisdom tooth
o Pathological gemination/concrescence
o Extracting in wrong order (should start with posterior)
o Inadequate alveolar support
Why is support important for preventing maxillary tuberosity fractures
Providing support means that you can feel the bone moving before the tooth is taken out which means you can stop before the real damage is done
How do you diagnose tuberosity fracture
o Noise
o Movement noted both visually or with supporting fingers
If felt prior to tooth removal, can splint the tooth in place
o More than one tooth movement
o Tera in soft tissue of palate
How do you manage tuberosity fracture
- reduce and stabilise
or - dissect out and close wound primarily
How should you reduce and stabilise the tuberosity
Orthodontic buccal arch wire with composite
Arch bar
Splints (lab made)
If you splint the teeth post tuberosity fracture, what should be done
Remove/treat pulp
Ensure it is out of occlusion
Consider antibiotics and antiseptics
Post-operative instructions
Remove the tooth surgically 4-8 weeks later
