antrum Flashcards
describe the growth of the antrum (5)
- rapid 0-4yo then gradual 4-8yo
- width and length complete by 12yo
- height increases until 18yo
- slower growth in females after 8yo, stops earlier
- loss of upper teeth = antral floor encroaches
describe the drainage of paranasal sinuses (2)
- middle meatus drains frontal, maxillary, anterior and middle ethmoidal sinuses
- sphenoethmoidal recess drains the posterior ethmoidal and sphenoidal sinuses
what are sinuses lined by?
respiratory mucosa (pseudostratified columnar ciliated epithelium)
give some functions of the antrum (5)
- warm and humidify air
- defence against microbial ingress (cilia)
- decrease weight of skeleton
- voice resonance contribution
- “crumple zone” (protects brain in trauma)
what innervates the sinuses?
maxillary nerve branches = superior alveolar nerves and infraorbital nerve
what is the blood supply of the antrum?
maxillary artery branches = infraorbital, posterior superior alveolar arteries
what radiographic imaging could be used to view the antrum? (4)
- PA
- occlusal (limited value)
- DPT
- OM view
how to tell the difference between cyst and sinus? (2)
- sinus has radiolucent channels (vascular)
- sinus has a wiggly line, cyst can be scalloped or rounded
what walls/surfaces of the maxillary sinus can be seen on the DPT?
- floor
- anterior
- posterior
- roof/floor of orbit
what developmental disorders can affect the antrum?
- aplasia (failure to develop)
- hypoplasia
- hyperplasia
describe maxillary sinus hypoplasia (what, radiograph, other)
- unilateral >
- reduction of sinus size and compensatory enlargement of nasal cavity
- increased radiographic height of alveolar process
- increased risk of infections due to narrow sinus drainage into ostium
define maxillary sinusitis
inflammation of the maxillary sinus with mucosal thickening + mucopus/pus
give some possible causes of acute sinusitis (up to 6)
- URTI (intrinsic)
dental extrinsic: (maxillary sinusitis of odontogenic origin) - PA inflammation/infection
- endo treatment
- OAC/OAF
- root displacement/implant extrusion into sinus
- surgery (eg ridge augmentation)
give some specific sinogenic s/s (4)
- unilateral nasal obstruction/discharge
- pus in middle meatus
- concurrent/recent URTI
- increased pain on vertical change in head position
give some shared sinogenic and dental s/s (5)
- increased pain with changes in atmospheric pressure
- unilateral maxillary pain
- sleep disturbance
- facial swelling/rare cases of acute ethmoid/frontal sinusitis
- upper buccal sulcus swelling (rare, large antrum)
how is sinusitis managed? (6)
- steam inhalations (Karvol, Olbas oil)
- decongestants - ephedrine 0.5% spray/drops (QDS <7 days) or xylometazoline
- saline irrigation of nasal cavity
- avoid long haul flights
- antibiotics ONLY if signs of spreading infection, persistent symptoms >7 days, very severe s/s, immunocompromised, cystic fibrosis
– amoxicillin, doxycycline or clarithromycin 7/7 - refer if systemically unwell or orbital involvement
what may be used as a decongestant for sinusitis and what do these do?
- ephedrine 0.5% spray/drops (QDS <7 days)
- xylometazole
- constrict nasal lining to widen ostia
why should decongestants not be used for >7 days?
to avoid rebound effect of mucosal swelling
when are antibiotics indicated for sinusitis? (4)
- signs of spreading infection
- persistent symptoms >7 days or very severe s/s
- immunocompromised
- cystic fibrosis
what is the difference between acute and chronic sinusitis?
acute = up to 4 weeks, self-limiting, symptomatic treatment
chronic = 8-12 weeks, rarely painful
what may cause chronic sinusitis? (4)
- acute infection and decreased ciliary action –> bacterial infection
- poor draining - high position of ostium
- poor draining from middle meatus (nasal polyps, deviated nasal septum, concha bullosa)
- dental causes
what is the management of chronic sinusitis (as a GDP)? (2)
- identify and treat any underlying dental cause
- refer to ENT - steroid nasal sprays, decongestants, surgery to remove obstructions/FESS
causes of maxillary sinusitis of odontogenic origin (6)
violation of sinus membrane by intimate association of maxillary teeth with antral floor:
- PA disease
- advanced periodontitis
- cysts (radicular, dentigeous)
- pathological jaw lesions
- facial trauma
- iatrogenic = post-XTN/implant/augmentation/maxfax, displaced tooth/foreign body/implant, endo treatment
how may endodontic treatment cause maxillary sinusitis?
- over-instrumentation
- sodium hypochlorite accident
- extrusion of filling material
describe the four stages of maxillary sinusitis of endodontic origin progression
1 = asymptomatic with minimal local reaction in antral floor periosteum/mucosa for months-years
- mucosal thickening radiographically
2 = beyond sinus floor, partial/total obstruction of sinus
- similar s/s to sinogenic sinusitis
3 = involvement of nasal cavity, ethmoid and frontal sinuses
4 = spread to other areas
what issues can be caused by severe spread of maxillary sinusitis of endodontic origin? (3)
- orbital cellulitis and blindness
- meningitis, brain abscess
- cavernous sinus thrombosis
how does maxillary sinusitis of endodontic origin usually present? (2)
(usually present to GP or ENT)
- unilateral sinusitis on the side of dental pathology
- variable s/s similar to acute sinusitis, endodontic symptoms may be absent (apex within sinus)
what may imaging show in maxillary sinusitis of endodontic origin? (4)
- PA RL
- PA osteoperiostitis (antral halo)
- PA mucositis (mucosal thickening)
- sinus obstruction (opacification)
how is maxillary sinusitis of endodontic origin managed? (2)
- remove cause of infection (RCT, endodontic microsurgery, intentional reimplantation, XTN)
- consider adjunctive medical or surgical management and f/u with ENT (esp chronic s/s)
management of displaced tooth in the antrum (4)
- saline flush, explore socket with high volume suction and good lighting
- inform pt and re-radiograph
– loose in antrum = Caldwell-Luc approach/endoscopic removal
– absent = check suction, swallowing or inhalation (CXR at A&E)
if a tooth fragment is inhaled, where is it likely to end up?
right main bronchus
what is the Caldwell-Luc approach and what is it used for (3)?
surgical procedure involving a MPF and cavity in the upper buccal buttress
- removal of foreign bodies in antrum
- exposure and removal of tumours in/adjacent to antrum
- removal of odontogenic tumours/cysts
why is it important to check the antrum on a CBCT pre-implants?
higher risk of rhinosinusitis after implant surgery if the pt has pre-operative chronic sinusitis (should be managed before implants)
s/s of OAC/OAF
- leakage of fluid into the nose
- air escape from the nose into the mouth
- sinusitis s/s
management of OACs/OAFs (8)
- majority of OACs resolve without surgical treatment
- inform pt
- antral regime:
– amoxicillin
– Karvol steam inhalations
– ephedrine 0.5% nasal drops/spray
– NO nose blowing or long haul flights - review
- OAC/OAF present 2 weeks later = may need surgical closure with buccal advancement flaps +/- buccal fat pad
what type of fungal infection is more common in the sinus?
Aspergillus
what may sinus infection lead to (life-threatening)? give some s/s
orbital cellulitis (esp in young)
- eye swelling, proptosis, diplopia
- pain
- history of common cold/URTI
how is orbital cellulitis managed? (2)
- send to A&E for urgent CT scan
- IV antibiotics and surgical drainage by ophthalmology
describe central mucosal thickenings of the antrum (what, causes, types)
- mucosal thickenings >2mm
- type of inflammatory hyperplasia
- eg PA infections, RCTs, periodontitis, close relationship of maxillary teeth with sinus
- types = maxillary pseudocysts, mucous retention cysts, mucoceles
describe a maxillary pseudocyst (what, tx, radiograph)
- formed by accumulation of serum beneath periosteum, lifting it off the bone
- not epithelial-lined
- asymptomatic, harmless, no treatment needed unless blocking
- common on DPT as a dome-shaped radiopacity on antral floor
describe a sinus mucous retention cyst (what, where, radiograph, tx)
- no epithelial lining
- inflammation of epithelial lining with secretory duct obstruction and liquid accumulation
- most common in maxillary sinus
- common on DPT = dome/ball-shaped, no cortical outline, intact sinus floor, no alveolar expansion or effects on teeth
- no tx unless blocking
how can you tell the difference between central mucosal thickenings of the sinus and an odontogenic cyst?
odontogenic cyst would have a bony margin
how can you tell the difference between central mucosal thickenings of the sinus and malignancy?
malignancy would have bone destruction
how can you tell the difference between central mucosal thickenings of the sinus and polyps?
polyps are often smaller and multiple
describe sinus mucocele (what, s/s, tx, location)
- true cyst (epithelial and mucoperiosteal lining) containing mucinous secretions in blocked/obstructed sinus cavity (blocked ostium)
- benign, but may erode bone
- can cause significant pathology in periorbital region
- endoscopic removal/external surgery
- usually in frontal sinus, Japan (following external sinus surgery)
list some tumours which may involve the maxillary sinus (4)
- odontogenic cysts/tumours, ameloblastoma
- adenomas, myxomas, fibromas
- fibrous dysplasia, Paget’s
- osteoma
what are the most malignant tumours involving the maxillary sinus?
- 80% squamous cell carcinoma
- 10% acinic cell carcinoma (and others)
- metastases
malignant tumours affecting maxillary sinus - common demographic
middle-aged to elderly males
s/s of malignant tumours affecting the sinus (up to 10)
- space-occupying lesion in antrum
- orbital displacement, diplopia
- epistaxis, nasal obstructions
- unilateral facial pain, infraorbital paraesthesia, cheek numbess
- unilateral firm, non-infective facial swelling
- loss of radiopaque sinus outline
- palatal swelling
- non-healing extraction site
- loose maxillary teeth in absence of perio/PA disease
- trismus
what traumatic conditions can affect the maxillary sinus? (2)
- iatrogenic = dental tx
- middle facial bone fractures
list the categories of conditions affecting the antrum (5)
- developmental disorders
- diseases (inflammatory)
- tumours
- diseases outside sinus which may affect sinus as they grow
- trauma
