maxillary sinus Flashcards
what sinuses are there
- frontal sinus
-sphenoid
-ethmoid - maxillary sinus
what are the function of paranasal sinuses
- reasonance to the voice
- reserve chambers for warming inspired air
- reduce weight of skull
anatomy of maxillary sinus
- largest
-pyramid shaped cavity in maxilla
-15ml
embryology of maxillary sinus
- 3rd and 4th foetal months
- maxillary relatively large at birth
what is opening of maxillary sinus
- middle meatus
- 4mm
-superiorly on medial wall of sinus
-lined with mucosa - if inflammation - becomes narrow or blocked
what anatomical features can be found near/in maxillary sinus
- roots of maxillary molars
-alveolar canals transporting posterior superior alveolar vessels
what is the epithelium in maxillary sinus
- pseudo stratified ciliated collumnar epithelium
what to cilia do
- mobilise trapped particulate matter and foreign material within the sinus
- move this material toward the ostia for elimination into the nasal cavity
clinical significance of maxillary sinus
- OAC
-OAF - root in antrum
-sinusitis
-benign lesions
-malignant lesions
how does OAC/OAF occur
- taking out maxillary molar close to floor of maxillary sinus
-break bone or tear maxillary lining
diagnosis of OAC/OAF
- size of tooth
-radiographic position of rotor in relation to antrum
-bone at trifurcation of roots
-bubbling of blood - nose holding test
-vision
-suction
-blunt probe
what is OAF
- chronic
- OAC which doesn’t heal
-sinus tract - epithelial line tract from mouth to sinus
OAC management
- inform patient
if small or sinus lining intact
- suture margins
- encourage clot
- antibiotic ??
Small OACs <2mm usually heal with normal blood clot formation and routine mucosal healing
if large
- close with buccal advancement flap
post op instructions for OAC
- Minimising pressure formation within the sinuses and mouth
- dont blow nose
- dont use straw
- avoid smoking
- avoid singing
what is design of buccal advancement flap
- 3 incisions
-2 relieving and 1 crevicular
what might patient complain of in OAF
- 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)
what has to be done prior to buccal advancement flap in OAF
- excision of sinus tract
what are other flap design options
- buccal fat pad with buccal advancement flap
- palatal flap
- bone graft/collagen membrane
- rotated tongue flap
aetiology of fracture of maxillary tuberosity
- single standing molar
- unknown unerupted molar or wisdom tooth
- pathological gemination/concrescence
- extracting in wrong order
- inadequate alveolar support
-commonly involves maxillary sinus
diagnosis of fracture of maxillary tuberosity
- noise
-movement
-more than one tooth movement
-tear in soft tissue of palate
management of fractured maxillary tuberosity
- reduce and stabilise - if early
- orthodontic buccal arch wire with composite
- arch bar
- splints
- dissect out and close wound primarily
if splinting a maxillary tuberosity fracture remember
- remove or treat pulp
- ensure out of occlusion
- consider antibiotics or antiseptics
- post-op instructions
- remove tooth surgically 4-8 weeks later
what to do if root of tooth in maxillary antrum
- confirm radiographically - OPT, occlusal or PA
- decision on retrieval
how might a root or tooth in maxillary sinus be retrieved
- OAF type approach - through extraction socket
- caldwell luc approach
- ENT endoscopic retrieval
sinusitis and maxillary sinus
- close relationship of sinuses and posterior maxillary teeth
- aetiology of paranasal sinus inflammation and infection
- patients with sinusitis often present to 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
- allergens, inflammation , anatomy
- cellular damage that occurs to mucosal lining
- then build up of pressure
-opportunistic situation for bacterial overgrowth of normal flora
signs and symptoms of sinusitis
- Facial pain
- Pressure
- Congestion (fullness)
- Nasal obstruction
- Paranasal drainage
- Hyposmia
- Fever
- Headache
- Dental pain
- Halitosis
- Fatigue
- Cough
- Ear pain
- Anaesthesia / paraesthesia over cheek
differential dental diagnosis for sinusitis
- Periapical abscess
- Periodontal infection
- Deep caries
- Recent extraction socket
- TMD
- Neuralgia or atypical facial pain / chronic midfacial pain
indicators of sinusitis
- discomfort on palpation of infraorbital region
-diffuse pain in maxillary teeth - TTP all teeth
- head or facial movements make worse
treatment of sinusitis
decongestants
- ephedrine nasal drops 0.5% - 3x daily for 7 days
humidified air
treatment of bacterial sinusitis
- amoxicillin 500mg 3x for 7 days
-doxycycline 100mg 1x for 7 days
what is the other potential cause of sinusitis
- Very occasionally a non-resolving sinusitis may be due to a fungal infection
- This can cause expansion of the bony walls by increased mucus secretion and fungal growth
how may sinusitis be caused by trauma
- 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 conditions can be present in maxillary sinus
- benign sinus lesions
- polyps, papillomas, antral pseudocysts, mucoceles and mucous retention cysts
- Odontogenic cysts / odontogenic tumours expanding into the maxillary sinus
- Malignant lesions
- Primary tumours
- Local spread from adjacent sites
