maxillary sinus Flashcards
sinuses in the face
4
frontal sinus
sphenoid sinus
ethmoid air cells
maxillary sinus (dental most concerned)
embryology of sinuses
3
Formation occurs during 3rd and 4th foetal months, with evaginations of the mucosa of the nasal cavity
Maxillary and ethmoid relatively large at birth
Sphenoid and frontal undergo expansion within the first few years of life
3 functions of paranasal sinuses
- resonance to the voice
- reserve chambers for warming inspired air
- reduce the weight of the skull
maxillary sinus a.k.a
maxillary antrum
maxillary sinus anatomy
and dimensions
Usually, the largest of the sinuses
Pyramid-shaped cavity within the body of each maxilla
Volumetric space 15ml in average adult
Average dimensions: variation between people
* 37mm high
* 27mm wide
* 35mm antero-posteriorly
opening of the maxillary sinus (ostium)
5 points
Middle meatus (hiatus semilunaris)
Opening approx. 4mm diameter
Located superiorly on medial wall of sinus (large collection of fluid/mucous before it can drain)
Lined with mucosa
Can become narrow or blocked during episodes of inflammation/disease easily
posterior wall of maxillary sinus has
alevolar canals that transport the posterior superior alveolar vessels and nerves to the maxillary posterior teeth
maxillary sinus and roots of maxillary teeth
Roots of maxillary molars and sometimes premolars may project into the floor of the maxillary sinus
The roots may perforate the bone so that only the mucosal lining of the sinus covers them
epithelium of sinuses
pseudostratified ciliated columnar epithelium (produce mucous)
role of cilia in epithelium of sinuses
2
- mobilise trapped particulate matter and foreign material within the sinus
- move this material towards the ostia for elimination into the nasal cavity
pseudostratified ciliated columnar epithelium
ostia/ostium
opening of sinus
6 possible clinical issues that can occur to msaxillary sinuses
- Oro-Antral Communication (OAC) - Acute
- Oro-Antral Fistula (OAF) - Chronic
- Root in the antrum
- Sinusitis
- Benign Lesions
- Malignant Lesions
most common clinical issues involving maxillary sinus
OAC/OAF
aetiology of OAC/OAF
Extraction of toot/RR and due to close relation of floor maxillary antrum/sinus and tooth create a communication either by breaking bone of floor or ripping the mucosa lining and oral cavity(previously wasn’t there)
* Get bacteria ingress into sinus
* Affect function of sinus
how to dx OAC/OAF
7 main
- Size of tooth
- Radiographic position of roots in relation to antrum predict
- Bone at trifurcation of roots possible to come out in extraction
- Bubbling of blood
- Nose holding test gently - careful as can create an OAC; if just broken bone, lining can be intact and this can break it
- Direct vision
- Good light and suction – echo sound
Blunt probe (take care not to create an OAC) avoid
pre op assessment for risk OAC
3 indications from radiograph
close radiographic relation between roots and antrum
Loan standing upper molar has increased chance of communication and/or # tuberosity
Splayed roots increased chance
Arrow area – 26 can see maxillary sinus has been wrapped around the roots (less so on 16), very little bone – high chance communication and # tuberosity
OAC is
acute
just happened, immediate post extraction - can see bleeding, potential prolapse of lining of maxillary antrum
OAF is
chronic
communication made - management failed and opening persists - sinus tract has been created now
no bleeding
management of OAC
Inform patient
If small or sinus lining intact: majority
* Encourage clot
* Suture margins pack has risk of pushing into sinus
* Antibiotic (area of debate)
Post-op instructions most important
* Minimising pressure formation within the sinuses and mouth
* Avoid blowing nose, avoid sucking through straw, inflating balloon, smoking, avoid singing
Small OACs <2mm usually heal with normal blood clot formation and routine mucosal healing
If large or lining torn: Close with buccal advancement flap
acute
prognosis of OAC tx success depends on
size
small OACs <2mm usually heal with normal blood clot formation and routine mucosal helaing
if large or lining torn - close with buccal advancement flap
management of small OAC
5 points
Inform patient
Encourage clot
Suture margins pack has risk of pushing into sinus
Antibiotic (area of debate)
Post-op instructions most important
* Minimising pressure formation within the sinuses and mouth
* Avoid blowing nose, avoid sucking through straw, inflating balloon, smoking, avoid singing
post op instructions for pt with OAC
Post-op instructions most important
* Minimising pressure formation within the sinuses and mouth
* Avoid blowing nose, avoid sucking through straw, inflating balloon, smoking, avoid singing
post op instructions for pt with OAC
Post-op instructions most important
* Minimising pressure formation within the sinuses and mouth
* Avoid blowing nose, avoid sucking through straw, inflating balloon, smoking, avoid singing
pts with OAF may complain of
6
- 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 (discussed later)
management of OAF
excision of sinus tract (like a tube)
raise Buccal Advancement Flap - same design as large OAC
antral washout - not always done
followed by same closure as OAC
chronic
5 flap design options for OAC/OAF
2 main
**Buccal Advancement Flap **
* most common, but can fail esp in bigger communication
Buccal Fat Pad with Buccal Advancement Flap
* thicker flap, can be better for larger communication
* high in sulcus - yellow globular fatty tissue
* 2 layer closure rather than 1, can cause more bruising and more prominent cheek bone on one side
Palatal Flap
very painful, raw exposed bone on palate, thick tissue for flap coverage
Bone Graft/Collagen Membrane usually only when others failed
Rotated Tongue Flap (Historical)
aetiology of fracture of maxillary tuberosity
5
- Single standing molar
- Unknown unerupted molar or wisdom tooth
- Pathological gemination/concrescence
- Extracting in wrong order
- Inadequate alveolar support with non-dominant hand
Commonly involves maxillary sinus
aetiology of fracture of maxillary tuberosity
5
- Single standing molar
- Unknown unerupted molar or wisdom tooth
- Pathological gemination/concrescence
- Extracting in wrong order
- Inadequate alveolar support with non-dominant hand
Commonly involves maxillary sinus
dx of maxillary tuberoisty #
4
noise
movement notes both visually or with supporting fingers
more than one tooth movement
tear in soft tissue of palate
management options for fracture of maxillary tuberoisty
2 methods
Reduce and stabilise to tooth in front
* Orthodontic buccal arch wire with composite
* Arch bar
* Splints (lab-made) – challenge as need impression
Dissect out and close wound primarily
* Pulled too far from blood supply so no chance healing
if splint the tooth remember to
5
Remove or treat pulp
Ensure it is out of occlusion
Consider antibiotic and antiseptics
Post-op instructions
* Similar to OAC instructions
Remove the tooth surgically 4-8 weeks later after bone healing
suspect root/tooth in maxillary sinus - what to do
Confirm radiographically by OPT, occlusal, or periapical (+/- CBCT usually on day of retrieval)
Decision on retrieval
* If in doubt or retrieval difficult – refer
best outcome if part of tooth/root end up in maxillary antrum
fractured part of floor of antrum but not torn lining of antrum, but accidentally pushed root up so wedged between lining of maxillary antrum and alveolar bone
* won’t cause sinusitis, pt issues or will move as wedged in place
So if pt doesn’t consent to further surgery it is least likely to cause problems (cannot guarantee none)
retrieval options for root/tooth in antrum
3
OAF-type approach / through the extraction socket most common
* Open fenestration with care
* Suction – efficient and narrow bore
* Small curettes - careful esp if think lining isn’t breached yet
* Irrigation or ribbon gauze
* Close as for OAC
Caldwell-Luc approach
* Buccal/Labial sulcus
* Buccal window cut in bone more anterior to where root is and look downwardly posterior into sinus
ENT if unsuccessful or hard on radiograph
* Endoscopic Retrieval
when you examine pt with maxillary discomfort remeber
close relationship of sinuses and the posteiror maxillary teeth
aetiology of paranasal sinus inflammation and infection
pt with sinusitis often present to the dentist first
aetiology of sinusitis
Most are precipitated by the effects of a viral infection
* Inflammation and oedema
* Obstruction of ostia
* Trapping of debris within sinus cavity
Mucociliary clearance patterns may be altered by:
* Allergens
* Inflammation
* anatomic abnormalities
Normal physiological function is further disrupted by the cellular damage that occurs to the mucosal lining, this affects normal ciliary function
When the sinus can no longer evacuate its contents efficiently
* build up of pressure, also produce an area of stagnation in sinuses
* opportune situation for bacterial overgrowth of normal flora - leads to a bacterial infection –* opportunistic infection, viral initially*
signs and symptoms of sinusitis
- Facial pain
- Pressure
- Congestion (fullness)
- Nasal obstruction
- Paranasal drainage
- Hyposmia (reduced sense of smell)
- Fever
- Headache
- Dental pain
- Halitosis
- Fatigue
- Cough
- Ear pain (referred pain)
- Anaesthesia / paraesthesia over cheek
dental causes to rule out is sinusitis suspected
periapical abscess
periodontal infection
deep caries
recent extraction socket
TMD
neuralgia or atypical facial pain/chronic midfacial pain
4 dental indicators for sinusitis
Discomfort on palpation of infraorbital region
A diffuse pain in the maxillary teeth
Equal sensitivity from percussion of multiple teeth in the same region
* Doesn’t make sense all TTP as no evidence of dental disease
Pain that worsens with head or facial movements
3 tx aims for sinusitis
tx presenting symptoms
reduce tissue oedema
reverse obstruction of the ostia - allow drainage
tx for sinusitis
Decongestants reduce mucosal oedema
* Ephedrine nasal drops 0.5% one drop each nostril up to three times daily when required (use for a maximum of 7 days)
* Effective but only short term use as cause atrophy of nasal lining
Humidified air is also helpful (steam/menthol inhalations)
Antibiotics for sinusitis should only be used if symptomatic treatment is not effective/symptoms worsen AND signs and symptoms point to a bacterial sinusitis
* Amoxicillin 500mg, three times a day, for 7 days (first line) OR
* Doxycycline 100mg, once a day, for 7 days (200mg loading dose)
check SDCEP guidance
tx for sinusitis
Decongestants reduce mucosal oedema
* Ephedrine nasal drops 0.5% one drop each nostril up to three times daily when required (use for a maximum of 7 days)
* Effective but only short term use as cause atrophy of nasal lining
Humidified air is also helpful (steam/menthol inhalations)
Antibiotics for sinusitis should only be used if symptomatic treatment is not effective/symptoms worsen AND signs and symptoms point to a bacterial sinusitis
* Amoxicillin 500mg, three times a day, for 7 days (first line) OR
* Doxycycline 100mg, once a day, for 7 days (200mg loading dose)
check SDCEP guidance
fungal infections sinusitis
very rare - if have a non-resolving sinusitis, check for this
can cause expansion of the bony walls by increase mucus secretion and fungal growth (happens in any long standing sinus infection)
* REFER TO ENT
can trauma cause sinusitis
yes - by violating the integrity of the bony cavity and sinus membrane
e.g.
* Sinus wall fractures
* Orbital floor fractures
* Root canal therapy
* Tooth extractions
* Dental Implants/Sinus lifts (perforate sinus, reduce volume of max sinus to allow inc bony deposition for bone graft)
* Deep periodontal treatment
* Nasal packing
* Nasogastric tubes
* Mechanical (nasal) intubation
possible traumas that can damage the sinus bony walls and membrane
can cause sinusitis
9
- Sinus wall fractures
- Orbital floor fractures
- Root canal therapy
- Tooth extractions
- Dental Implants/Sinus lifts (perforate sinus, reduce volume of max sinus to allow inc bony deposition for bone graft)
- Deep periodontal treatment
- Nasal packing
- Nasogastric tubes
- Mechanical (nasal) intubation
benign sinus lesions
can be chance findings on OPT
e.g. polyps, papillomas, antral pseudocysts, mucoceles and mucous retention cysts
or odontogenic cysts/tumours expanding into maxillary sinus
malignant lesions in maxillary sinus
rare
primary tumous e.g. of the bone or lining
or local spread from adjacent sites e.g. SCC of maxilla invades the sinus
