maxillary antrum Flashcards
3 main fcts of paranasal sinuses
resonance to voice
reserve chamber for warming inspired air
reduce weight of skull
embryology
form during 3rd and 4th foetal months
- evaginations of mucosa in nasal cavity
maxillary and ethmoid fairly large at birth
sphenoid and frontal - expansion during first few yrs of life
opening - ostium
middle meatus (hiatus semilunaris)
opening approx 4mm diameter
located superiorly on medial wall of sinus
- position can predispose to sinusitis - hard to drain
lined with mucosa
can become narrowed/blocked during episodes of inflammation/disease
differential diagnoses
dental sinus TMD tumours MS atypical facial pain
clinical significance
OAC/OAF root in antrum sinusitis benign lesions malignant lesions
when should you suspect a malignant lesion?
when you can’t see walls of sinus
which sinus is usually the largest?
MS
shape of MS
pyramid
dimensions of MS
av volumetric space 15ml in adult
37mm high
27mm wide
35mm AP
what are generally found on the posterior wall of the sinus cavity and what is the clinical significance of this?
alveolar canals that transport the posterior superior alveolar vessels and nerves to the maxillary posterior teeth
can get referred pain e.g. pts think they have toothache
MS and roots of molars and sometimes premolars
may project into the floor
roots may perforate the bone so that only the mucosal lining of the sinus covers them
if PA pathology could inflame the mucosa - can get mucosal thickening
MS lining
pseudostratified ciliated columnar epithelium
cilia mobilise trapped particulate matter and foreign material within the sinus and move it towards the ostia for elimination into the nasal cavity
diagnosis of OAC/OAF
size of tooth
radiographic position of roots in relation to antrum
bone at trifurcation of roots
bubbling of blood
nose holding test (careful as can create an OAC)
direct vision
good light and suction (echo)
blunt probe (careful as can create an OAC)
OAC pre-op assessment purpose
so you can warn pt - explain it is a 2D image so roots may not be as close but there is a risk
management of acute OAC if small or sinus lining intact
inform pt
encourage clot
suture margins
small OACs <2mm usually heal with normal blood clot formation and routine mucosal healing
management of acute OAC if large or lining torn
close - if you can get primary closure not under tension without a flap then do it
BAF
- 3-sided - straight or slightly splayed for wider base
- need to release periosteum (fibrous, inelastic)
- paint line with scalpel where relieving incisions end
- once you have released it the flap becomes v elastic
so can cover socket w no tension
- non-resorbable (prolene)
- combination of sutures to keep it closed (mattress
sutures evert edges so get better healing as mucosa
not interrrupted
acute OAC antibiotics
perforation introduces oral bacteria
use prophylactic antibiotics
7 days
amoxicillin or doxycycline
acute OAC POIs
review appt in a couple of days don't forcibly blow nose or stifle a sneeze (by pinching nose) - sneeze with mouth open steam/menthol inhalation to keep sinuses clear avoid using straw no smoking don't prod area no vigorous mouthwashing no wind instruments