Surgical Aspects of the Maxillary Antrum

Question 1

What shape is the maxillary antrum?

Answer 1

Pyramidal shape

Apex is facing laterally

Question 2

What is the roof of the antrum?

Answer 2

Orbital floor (brittle and thin) = more likely to fracture - where infraorbital nerves come through
Infraorbital bundle traverses

Question 3

Medial wall of the maxillary antrum?

Answer 3

Lateral wall
Contains ostium
Cartilaginous in places

Question 4

Floor of the maxillary antrum?

Answer 4

Alveolar process of maxilla
Hard palate
Thinnest near tooth bearing alveolus 
In children adjacent to nasal floor
In adults 5-10mm lower
Close to apices of teeth

Question 5

Anterior wall of the maxillary sinus?

Answer 5

The cheek area

• Also forms lateral wall with lateral maxilla
• Should call antero-lateral wall
• Contains canine fossa = infection of canine can extend into maxillary sinus
• Thinnest part <2mm thick
• Good for surgical access

Question 6

What does the maxillary sinus drain into?

Answer 6

Drains into nose via ostium
Ostium is halfway up the medial wall
Efficient cilia - beat towards ostium

Question 7

What is an oro-antral communication?

Answer 7

An open communication between the oral cavity and maxillary sinus

Floor can extend from molar region to canine
Root apices closely associated

Question 8

Most common tooth/root to have an OAC?

Answer 8

Palatal root of first molar

Question 9

How to diagnose an OAC?

Answer 9

Clinical/radiographic signs:

• Movement of antral lining during respiration
• Emanating bubbles from socket during respiration
• Hollow sound when aspirating socket
• Fogging of mirror
• Extracted tooth attached to concave bone or fractured tuberosity
• Post op radiograph - defect sinus floor

Question 10

Conservative management of OACs?

Answer 10

Many OACs undetected
- Heal spontaneously

Instructions

• No nose blowing
• OHI

Antibiotics - broad spectrum (penicillin)
Splints
Decongestants (eucalyptus oil)

Question 11

Active treatment for OACs?

Answer 11

Suturing
- Resorbable/non-resorbable
- Packing - resorbable/oxidised cellulose
Non-resorbable - fistula: BIPP (ismuth iodoform paraffin paste), ribbon gauze

Splints
Antibiotics, decongestants

Question 12

What is a fistula?

Answer 12

Communication of the oral cavity and maxillary sinus lined by epithelium (>7 days after surgery)

Question 13

What can a healed OAC form?

Answer 13

An oro-antral fistula

Question 14

Signs and symptoms of oro-antral fistula?

Answer 14

Purulent discharge
Bad taste
Liquid discharge through nose
Air escape - both directions (do NOT do acutely)
- Can have false negative result due to infection/debris
Episodic sinusitis
Nasal voice
Epistaxis
Prolapse of antral mucosa into mouth
Whistling noise
Radiographic evidence - CBCT/Occipitomental

Question 15

Types of surgical repair?

Answer 15

Buccal advancement flap
Buccal fat pad graft
Palatal rotation/palatal finger flap
Trapezoid flap

Question 16

Surgical closure - buccal advancement flap features?

Answer 16

Raise full thickness mucoperiosteal buccal flap
Release periosteal fibres to bring it over the OAC
If a fistula cut the fistula out as well as the flap to remove the epi lining

Good success rate
Low morbidity
Good blood supply

BUT decrease in vestibular sulcus depth - prosthetic implications (E.G. difficulty with dentures)

Question 17

Palatal rotation flap?

Answer 17

Relies on greater palatine artery
Length/width ratio important
- >2.5 = flap necrosis
Painful donor site
Seldom used, useful for larger OAFs
Leave to heal by secondary intention

Question 18

Buccal fat pad graft features?

Answer 18

Do a buccal advancement flap and take buccal fat and pull it into the hole before closing it up

Question 19

What epi lines the maxillary sinus?

Answer 19

Lined by respiratory epithelium (ciliated pseudostratified columnar epithelium)

Question 20

What is the largest paranasal sinus?

Answer 20

Maxillary sinus

Question 21

Functions of the maxillary sinus?

Answer 21

Reduces weight of skull
Voice resonance
Humidification
Mucous production

Question 22

Anatomical borders of the maxillary sinus?

Answer 22

Infraorbital surface of maxilla (Superior)
Alveolar process (Inferior)
Lateral wall of nose (Medial)
Zygoma (Lateral)
Maxilla (Anterior/medial/lateral)

Question 23

OAC risk factors?

Answer 23

Long/ankylosed roots
Lone standing molar
Hypercementosis, bulbous roots 
Loss of apical periapical bone 
Pneumatisation of sinus
Impacted upper molar 
Poor technique - excessive force
Cleft lip and palate
Root fracture

Question 24

Risk factors of OACs?

Answer 24

Thinner antral floor (1-7mm)
Bone resorption related to chronic apical periodontitis
Early and complete increase risk of OAC

Question 25

OAC management?

Answer 25

<2MM: - Promote spontaneous healing - Gentle irritation of socket and debridement of sharp bone - Resorbable haemostatic agent (surgicel) - Suturing loose edges - Antral regime and review - Vacuum splint 2-4mm = conservative vs surgical repair - assess risk factors >4mm or OAF = surgical repair

Question 26

Common displaced foreign objects? How to avoid displacing objects?

Answer 26

Upper 3rd molars 0.3-3.8% of iatrogenic cases of foreign body entrapment Upper 6 palatal root >3rd molar > 2nd molar root Avoid apical pressure Controlled pressure and safe technique

Question 27

Transalveolar approach of retrieving a displaced foreign object?

Answer 27

1. Fill sinus with saline - use suction to retrieve root 2. 2 or 3 sided buccal flap - flap design should permit closure with advancement: - Flap elevated subperiostally - Bone removal to enable visualisation and removal of interdental septae - Retrieve root with tweezers - Closure with buccal advancement (+/- fat pad or collagen membranes)

Question 28

How to retrieve a displaced foreign object?

Answer 28

1. Alveolar approach 2. Caldwell-Luc approach 3. Functional endoscopic sinus surgery (FESS) Retrieve Light Suction Locations - is it between mucosa and alveolar bone or between intact sinus lining and floor of sinus

Question 29

Caldwell-Luc procedure?

Answer 29

Create incision in lateral aspect (premolar region) Create buccal window = access into sinus Flush object out

Question 30

Pros caldwell-luc?

Answer 30

``` Trapdoor approach Good access Preserves alveolar bone Method of choice for delayed procedures Direct vision ```

Question 31

Cons of caldwell-luc?

Answer 31

``` Trauma, loss of vitality to adjacent teeth Fistula formation Epistaxis Intraorbital nerve damage - Neuralgia - Paraesthesia ```

Question 32

Functional endoscopic sinus surgery features?

Answer 32

Conservative Maxillary sinus access via enlarged middle meatus antrosotomy Minimises complications associated with surgical options Expensive, time consuming

Question 33

Risks of functional endoscopic sinus surgery?

Answer 33

Risks - infection, epistaxis, CSF leak, difficulty retrieving posterior/inferior or large foreign body

Question 34

When choosing to delay retrieving a displaced foreign object, what should you do?

Answer 34

``` Document info (size, position) Radiograph - PA, OPT, OM, CT Suture socket Antibiotics Refer ```

Question 35

Fractured tuberosity features?

Answer 35

``` Most distal aspect of maxilla Contains socket of 3rd molar Fracture - cause for concern: - Large OAC - Stability issue later for prosthetics Associated with upper molar extractions - usually 7, 8 ```

Question 36

Fractured tuberosity risk factors?

Answer 36

``` Divergent/dilacerated/ankylosed roots Removal of impacted upper molar Lone standing upper molar Pneumatised maxillary sinus Increased age Poor technique - Uncontrolled force, inadequate maxillary alveolus support, excessive elevation ```

Question 37

Clinical signs of fractured tuberosity?

Answer 37

Tooth and tuberosity are felt to move synchronously with extraction Fracture noise Palatal tear Bleeding Assess - continue vs abandon extraction, immediate vs delayed repair?

Question 38

How to manage fractured tuberositys IF it's still attached to the periosteum? (realising fracture early)

Answer 38

1. Rigid spliting to adjacent teeth (composite and ortho wire) - Soft diet, antibiotics, rebook for surgical extaction in 6-8 weeks) 2. Or section crown to enable roots and tuberosity to heal and suture - Soft diet, antibiotics. Rebook for surgical extraction 6-8 weeks 3. Remove fractured tuberosity (if small) - subperiosteal dissection of mucoperiosteum off the fragment

Question 39

If fractured tuberosity completely separate from soft tissues +/- OAC management?

Answer 39

Smooth sharp edges residual bone If no OAC - suture and antral regime and review If OAC - treat according to defect size and antral regime and review

Question 40

Symptoms of sinusitis?

Answer 40

``` Bacterial or viral Mimic toothache Nasal discharge Pressure - tender Pain when bending over/lying down ```

Question 41

Tx of chronic sinusitis?

Answer 41

Bacterial - broad spectrum antibiotics (amoxicillin - if not working then co-amoxiclav), decongestants - If not resolved refer to ENT Chronic - antral wash out, nasal surgery