Maxillary Antrum Flashcards
What is the maxillary antrum?
The largest paranasal sinus
Pyramidal shaped and bilateral
What is maxillary antrum lined with?
Respiratory epithelium = ciliated pseudostratified columnar epithelium
4 functions of maxillary antrum?
Reduce weight of skull
Voice resonance
Humidification
Mucous production
How does maxillary antrum drain?
Drain into nose via ostium (half way up medial wall)
Efficient cilia beat towards ostium
NOT DEPENDENT ON GRAVITY
What are the anatomical borders of the antrum?
Infraorbital border - superior
Alveolar process - inferior
Lateral wall of nose - medial
Zygoma - lateral
What nerve bundle transverse the roof of antrum?
Infraorbital bundle in orbital floor
Branch of maxillary nerve from trigeminal
Sensory innervation - skin lower eyelid, side of nose, nasal septum, part of cheek and upper lip
No motor
What features would you see on medial wall of sinus?
Middle and inferior turbinates
Ostium - cilia push mucous = drainage
What features would you see on the floor of the sinus?
Alveolar process of maxilla and the hard palate
Close to apices of teeth
Is there a difference in the floor of the sinus in children and adults?
In children alveolus adjacent to nasal floor
In adults 5-10mm lower
What would you expect to see on the anterior wall of the maxilla?
The cheek
Thinnest part - good surgical access
Canine fossa
What is an OAC?
Open communication between oral cavity and maxillary sinus
Where does floor of sinus extend?
Often molar region to canine
Where is OAC most likely?
Palatal root of first molar
What roots have RFs for OAC?
Long, divergent, dilacerated or ankylosed roots
Hypercementosis
What are other RFs for OAC?
Lone standing molar Loss apical periodical bone Pneumatisation of sinus Impacted upper molar Cleft lip and palate
What operator technique are RF for OAC?
Poor technique - excessive force, wrong instruments
Displacement of foreign object into sinus
Tuberosity fracture
What pt factors post surgery could lead to OAC?
Failure to follow antra regime
Build up of pressure in cavity - nose blowing, sneezing, altitude
What teeth are at most clinical risk?
Upper second molar (most risk) Upper first molar Upper third molar Upper secondary premolar Upper first premolar
What are 3 important factors considering risk of OAC?
Thickness of antral floor
Bone resorption related periodontitis
Early and complete increase risk of OAC
What are signs and symptoms of OAC?
Purulent discharge Bad taste Liquid regurgitation through nose Air escape
What test can be used to check for air escape?
Valsalvin test
What are clinical signs of OAC?
Movement of antra lining during respiraton
Bubble from socket during respiration
Hollow sound when aspirating socket
Fogging of mirror
Extracted tooth attached concave bone or tuberosity
What radiographic sign can indicate OAC?
Defect in sinus floor
What is management of OAC less 2mm
Promote spontaneous healing Gentle irrigation of socket + debridement of sharp bone Resorbable haemostatic agent (Surgicel) Suturing loose edges Antral regime + review Vacuum splint
What is management of OAC that is 2-4m?
Consider conservative vs surgical repair
Assess- pt clinical signs, general RFs, MH, SH, OH
What is management of OAC >4mm
Surgical repair
What is the conservative tx of OACs?
Many undetected and will heal spontaneously Ab - broad spec (penicillin) Splint - aid healing Decongestants Pt instructions
What pt instructions should you give re OAC?
No nose-blowing
No flying altitude, don’t suck straws
Steam inhalation
Good OH
What are the active tx options of OAC?
Suture
Packing (resorbable/ non-resorbable)
Splints
w/ conservative regimen
What is OAF?
Oral antra fistula
Communication of the oral cavity and maxillary sinus lined by epithelium
Difference OAC and OAF?
OAF - epithelialised lining develops
What are signs/ symptoms of OAF?
Purulent discharge Bad taste Liquid regurgitation through nose Air escape Episodic sinusitis Nasal voice Epistaxis (nose bleed) Prolapse antra mucosa into mouth Whistling sound
How can OAF be surgically repaired?
Buccal advancement flap - most common
Buccal fay pad graft
Palatal rotation
How is buccal advancement flap used to tx OAF?
Excised OAF lining together w/ antra sinus lining or granulation tissue
Why is buccal advancement flap most commonly used for tx of OAF?
Good success rate w/ low morbidity
Good blood supply from buccal periosteum
Disadv of buccal advancement flap for tx of OAF?
Reduction is vestibular sulcus depth - prosthetic implications
What is technique for buccal advancement flap for OAF?
Full thickness buccal mucoperiosteum flap is raised w/ flared margins to allow for advancement
Advancement to palatal side – periosteal release required in transverse direction
Sutured using vertical mattress
Important sits on sound bone
Palatal mucosa can be incised
OAF need to surgically remove fistula before closed
What does buccal fat pad graft for tx of OAF involve?
Involve use of highly vascular fat surrounded by buccinator and masseter
Blunt dissection and pulled over to close defect then fat sutured
What anatomy do you need to be careful of when using buccal fat pad graft?
Parotid duct and papilla - pierce buccinator at anterior border
When is buccal fat pad graft useful?
Useful for delayed closure of larger defects
What does palatal rotation rely on?
Greater palatine artery
Why is palatal rotation not often used?
Painful donor site
Healing by secondary intention
Length/ width ratio important - flap necrosis
How to avoid displacement of foreign objects?
Awareness - radiograph, awareness of RFs
Avoid apical pressure
What are RFs for displacement of object into sinus?
RF - age, RCT, ankylosis, proximity
What are the most common teeth to be involved in displacement?
Upper 6 palatal root
3rd molar - whole tooth
2nd molar root
What are the 3 approaches to management of displaced object?
- Alveolar approach
- Caldwell-Luc approach
- Functional endoscopic sinus surgery - FESS
What radiographs are useful when managing displacement?
Intra-oral PA
OPT
CBCT - assess ability of retrieval
Used to diagnose and identify location and extent of displacement
When can retrieval be used?
When displacement in closer than think - between mucosa and alveolar bone or between sinus lining and floor
Use light and suction
What is transalveolar approach?
Fill sinus w/ saline and use suction to retrieve
Use flap w/ bone removal to aid visualisation
What is Caldwell-Luc procedure?
If not obviously retrievable by trans alveolar
Required GA
What are pros and cons of Caldwell-Luc procedure?
Pro - trapdoor approach = good access and persevere alveolar bone
Con - traumatic, loss vitality adjacent teeth, fistula formation, infra-orbital nerve damage
What is procedure of Caldwell-Luc?
Raise flap in buccal sulcus above premolar teeth to create lateral window
What is FESS?
Conservative approach where sinus access via enlarged middle meatus antrosotomy
Minimise associated complications but expensive, time consuming and need skilled operator (ENT)
What are 3 management decisions of tx of displaced objects?
Retrieve
Delay
Refer
What to do if delay tx of displaced object?
Document
Radiograph
Ab
Refer
Post-op advice when displaced object?
Similar conservative regimen Decongestants Abs Avoidance nose blowing OH
Features of the tuberosity?
Most distal aspect of maxilla
Contains socket of third molar
Why are fractures of tuberosity a concern?
Cause large OAC
Stability issue for later prosthetics
What are RFs of fractured tuberosity?
Upper molar XLA Roots - divergent, dilacerated, ankylosed Lone standing molar Pneumatised sinus Increased age Poor technique
Why dose increased age increase risk of tuberosity fracture?
Antrum larger, expanded, pneumatised - floor lower down
What poor techniques can lead to fractured tuberosity?
Uncontrolled force
Inadequate maxillary alveolar support
Excessive elevation
Clinical signs of fractured tuberosity?
Tooth and tuberosity move synchronously w/ XLA
Fracture noise
Palatal tear - bleaching mucosa
Bleeding
What does management of tuberosity fracture depend on?
If tuberosity attached to periosteum or not
How to manage fracture if tuberosity attached to periosteum?
- Splinting to adjacent teeth
- Conservative management - soft diet, ab and re-book for surgical XLA (6-8 weeks)
- Section crown to enable roots and tuberosity to heal
- Remove fractured tuberosity - subperiosteal dissection off fragment
How to manage fractured tuberosity if separated from soft tissue +/- OAC?
Smooth sharp edges residual bone
No OAC - suture and antra regime
OAC - tx according to defect size
How can implants cause injury to sinus?
Inadequate height - injury to sinus floor
Overcome w/ sinus life procedure - increase vertical volume of bone
What is an internal sinus lift?
Use summers technique
Aim: maintain integrity of sinus lining, limit graft to restore alveolar bone and avoid impaired sinus drainage
What is chronic sinusitis?
When remains persistent
Can be bacterial or viral
Symptoms of chronic sinusitis?
Mimic toothache, nasal discharge, pressure/ pain when bending
How to tx bacterial sinusitis?
Abs
Decongestants
How to tx chronic sinusitis?
Antra wash
Nasal surgery
ENT referral - esp if recurrent