2.15.23 Jo_Lateral sinus Flashcards
When is lateral sinus indicated? When is it contraindicated?
Indications:
* Atrophy of the posterior maxilla (RBH <5mm)
* Healthy maxillary sinus
Contraindications:
* Pre-existing sinus disease
* Sinus infection (sinusitis)
* Sinus pathology
For implants, when do you do staged vs. simultaneous placement with lateral sinus?
Staged: < 3 mm RBH
Simultaneous: ≥ 3 mm RBH
What is the average thickness of the Schneiderian membrane?
Insua 2016 COIR
CBCT = 0.79 mm
Histology: 0.33 mm
What is the vascular supply of the maxillary sinus?
Rosano ‘11
First part of the study:
* 15 fresh cadaver heads
* 30 maxillary sinuses
* The vascular network afferent to the
sinus was injected with liquid latex
mixed with green India ink through
he external carotid artery.
* Second part of the study
* 100 CT scans for pts scheduled for
sinus lift sx (200 sinuses in total)
Anastomosis
between AAA and Infraorbital Artery (IOA) in
dissection
= 100%
CBCT detection = 47%
Vertical distance from lowest point of the bony
canal to the alveolar crest
= 11.25 mm
Guliz ‘11 COIR
Prevalence of septa = 16%
Prevalence of sinus pathology = 25%
Artery was seen in 65% of all sinus
Mostly intraosseous 68%
Mean diameter of PSAA = 1.3 mm
Mean distance of PSAA to alveolar crest = 18 mm
Mean distance of PSAA to medial sinus wall = 11 mm
What is the presence of sinus septae?
Guliz ‘11 COIR: 16%
Pommer ‘12 JCP: 28.4 %
Qian ‘17: 32.6%
More from Pommer ‘12:
Septa height = 7.5 mm avg
Septa location:
Premolar = 24%
Molar = 55%
Retromolar regions = 21%
Septa orientation:
Transverse = 88%
—> most difficult to manage
Sagittal = 11%
Horizontal = 1%
What is the classification of sinus widths?
Chan ‘14 COIR
Lower boundary:
* Narrow: < 8
* Average: 8-10
* Wide >10
Upper boundary:
* Narrow < 14
* Average 14-17
* Wide > 17
How does sinus angle correlate with perforations?
Cho ‘01
Narrow = < 30 degrees
* Perforation: 37.5 %
Wide 31-60 degrees
* Perf 28.6%
> 61 degrees
* Perf 0%
What are the classifications for palatonasal recesses?
Chan ‘13
Obtuse (> 90 degrees) vs. Acute (< 90 degrees)
% of acute sites:
* 2nd PM : 15% acute
* 1st molar: 8.2 % acute
* 2nd molar: 2.4 % acute
These are measured at ≤ 15 mm from crest
How should a lateral sinus window be designed?
Baldini ‘16 COIR
RCT, 16 pts, bilateral sinus lift
* 6 X 6 vs. 10 X 8 mm window size
* No differences in amount of bone
augmentation and surgical time
* Smaller window showed less
patient discomfort (PROMs).
Avila-Ortiz ‘12
24 maxillary sinus augmentation on 21 pts (one pt was excluded due to infection after grafting)
* Appropriate window dimensions (AWD) in mm2
* Bone graft used: a mixture of cortical and
cancellous allograft particles
* FU 6 months
* Time of implant placement, bone core biopsies were harvested and analyzed histlmorphotrtically.
* Quantify:
* Vital bone (VB)
* Remaining allograft particles (RA)
* Non mineralized tissue (NMT)
Strong negative correlation between AWD and %VB (r =-0.6)
* Positive correlation between AWD and %RA
(r=0.56)
* NMT NSSD with AWD
AWD may have influence on the maturation
and consolidation of an allograft in the
maxillary sinus.
VB formation following maxillary sinus augmentation may be inversely proportional to the AWD.
What graft material should be used in the lateral sinus?
Froum ‘06
Allograft vs. Bio-Oss
Significantly more new vital bone was formed when allograft was used.
BioOss: 12.44 % vital bone
Residual graft: 7.65%
Allograft: 28.25% vital bone
Residual graft: 3.30%
Shanbhag ‘14
Observed bone reduction reported during graft maturation.
* NSD in volume reduction between different
materials.
* Space making materials seem to perform better.
Some loss of augmentation volume always
occurs after sinus augmentation (SA) during
early healing times.
* In general, less volume reduction expected
with xenograft/composite grafts but
augmentation loss has not been shown to
compromise implant success or survival.
Dr. Wang says: particle size has an effect
Does the membrane matter for lateral sinus?
Dr. Wang: Most people use resorbable collagen membrane since they don’t want to go back to retrieve ePTFE
Tarnow ‘00 (outdated technique using nonresorb membrane)
Prospective study on histologic and clinical
comparison of12 pts with bilateral sinus lift
* Nonresorbable membrane (e-PTFE)
vs.
No membrane
* More vital bone and higher implant survival
were observed in the membrane group
Wallance ‘05 IJPRD
Histomorphometric and clinical analyses of
51 pts with 64 sinus lift
* BioGIde vs. Gore-Tex vs. No membrane
* NSSD between membrane groups as to
vital bone formation and implant survival
Suarez ‘15 IJOMI
Meta-analysis of histomorphometric
outcomes of 37 studies
* Search with at least 6 pts and minimum
of 6-month follow-up
The presence of a barrier membrane over the window DOES NOT influence the amount of vital bone formation after sinus augmentation. = so you can go without a membrane over the outside of the graft.
* Type of grafting material used and healing time did not influence the histomorphometric outcome.
What are the long-term crestal bone changes of a sinus lift?
Urban ‘20 COIR
Retrospective case series study 86 pts 209
implants included
* Sagittal sandwich technique (Urban 2010):
* Particulate autogenous bone
* Anorganic bovine bone-derived mineral
and
Group S (residual alveolar ridge height 0.1-3.5 mm
Group M (height of 3.5-7mm)
Group C (native bone)
* Radiographs at baseline + annually w/ 10-yr FU
Findings: NSSD among groups
What is the Carl Misch “layered” technique for lateral sinus?
Top layer: 30x40 collagen membrane (Oramem)
3rd layer: BioOss + ampicillin liquid
2nd layer: 4:1 ratio of cortical to cancellous (e.g.: 2gcortical + 0.5g cancellous)
Lower layer: ≥5 mm autogenous bone (from tuberosity or adjacent sites) - this is the “cushion” that will surround the implant body
