sinus augmentation Flashcards
- What is required in the presurgical examination of sinus augmentation?
-Acute sinusitis
-Chronic sinusitis
-assessment on CBCT:
1 sinus
2 alveolar bone
3 OMC status
4 pathology
5 anatomy (blood vessels, septa)
when to intervene regarding chronic sinusitis
If the sinus membrane would occlude osteomeatal complex, then pathology should be removed at either the time of grafting or before by ENT (4m prior to grafting)
- Which are contraindications for sinus augmentation?
1) Smoking
2) OMC blockage (interferes with mucocilliary clearance and normal ventilation)
3) Sinusitis
4) mucous retention cyst (contraindicated if it will occlude the ostium; if it is >8mm refer to ENT, if <8mm it can be drained during sinus lift)
5) periapical or radicular cysts in the maxillary sinus
6) oroantral fistulas
7) sinus neoplasm
8) Antroliths (remove and allow healing)
What types of sinusitis are there?
-acute sinusitis
-chronic recurrent sinusitis
-odontogenic sinusitis associated with necrotic pulp tissue
-allergic sinus
-Bacterial, mycotic, and viral rhinosinusitis
why is smoking an issue for sinus lift
-increased risk of perf
-reduced chance of osseointegration
-wound dehiscence
-graft infection
- How would you pick between 1-stage and 2-stage techniques for sinus floor elevation?
1 stage:
-at least 5mm bone height
-good quality bone (D2 or D3) with cortical bone
-minimal occlusal forces
-no parafunction
2-stage:
-less than 5mm bone height
-Poor quality bone (D3 or D4) with no cortical bone
-High occlusal forces
-Parafunction
Why do you need residual bone for an implant in the 1 stage approach
-less bone to act as a blood supply for the new bone graft
-need bone for mechanical retention for primary stability
what is the function of the max sinuses
1) reduce the weight of the skull
2) produce mucous
3) resonance of a person’s voice
4) warming of air
what is the lining of the sinus histologically
-pseudostratified ciliated columnar epithelium
-then connective tissue
-underneath is periosteum
-this together is the Schneiderian membrane
dimensions of sinus
-height 36-45 mm
-width 25-35 mm
-length 38-45 mm
what is the ostium and how far is it from the floor of the sinus
- opening from the sinus to middle meatus
- Avg distance from floor is 28 mm
how many walls are there and what are they
1) anterior: 1-5mm thick, location of infraorbital a and n
2) superior: orbital floor with infraorbital canal
3) posterior pterygomaxillary region, contains the PSA n and a, pterygoid plexus of veings, and internal maxillary a
4) medial wall: separates the nasal fossa
5) floor: above max molars
6) lateral: zygomatic process (1-2mm thick)
blood supply of the sinus
-infraorbital artery
-posterior superior alveolar artery
-posterior lateral nasal artery
innervation of the sinus
ASAn
MSAn
PSAn
infraorbital n
incidence of septa
31%, usually between 2nd PM and 1st M
thickness of the sinus membrane
(Monje et al., 2016): 1.17mm radiographically, 0.48mm histologically
- What are the effects of occluding the ostium after sinus augmentation?
mucous build up as it cannot drain
-sinusitis
-mucocele
-inflammation and infection of sinus
signs of ostium occlusion
facial edema
pain
foul drainage from nose
classification of sinus contours
o Type A - narrow tapered
o Type B - tapering
o Type C - ovoid
o Type D - square
o Type E – irregular
o Subtype 1 - without recess
o Subtype 2 - with BSR
o Subtype 3 - with PNR
E:
o Subtype 1 - tooth roots protruding into sinus floor
o Subtype 2 - irregular sinus floor
o Subtype 3 - septa or exostosis present on sinus floor
