SINUS LIFT

PROCEDURES
 • Introduction
• Anatomical considerations
• History of sinus surgery
• Indications
• Contraindications
• Classifications
• SA 1 to SA 4 : in detail
Contents •
•
Other techniques
complications
• Conclusions
• References
 ANTRUM OF HIGHMORE?
• 1st discovered and illustrated by Leonardo da
vinci, but the earliest attribution of significance
was given by NATHANIEL HIGHMORE(the
British surgeon and anatomist)in 1651
 Surgical
Anatomy of
Maxillary Sinus
 Largest of the PNS
 Pyramidal shaped
cavity within the
body of the Maxilla.

 Pyramidal in shape
 base :lateral nasal
wall;
 apex : root of the
zygoma
FLOOR OF THE
SINUS
 Curved rather than
flat formed by
alveolar process of
the maxilla and lies
about 1cm below
the level of the floor
of the nose.
 Closely related to
root apices of the
maxillary premolar
and molar
  Imparts resonance to the voice
 Increases the surface area and lightens
the skull
 Moistens and warms inspired air
 Filters the debris from the inspired air
FUNCTIONS  Mucus production and storage
 Limit extent of facial injury from trauma
 Provides thermal insulation to important
tissues
 Serves as accessory olfactory organs.
 maxillary sinus expands and lowers down
(‘pneumatization’), resulting in reduced
subantral bone height, which is inadequate to
insert adequately long implants.
1. Residual subantral bone is less
than 10 mm in height.

2. Residual subantral bone is less

than 5 mm in width

3. Maxillary sinus is free of any

acute or chronic infection(sinusitis)
or pathology (cyst).
1. Heavy smoking
2. Acute sinus infection.
3.Recurrent history of chronic sinusitis.
4. Uncontrolled diabetes.
5. Maxillary sinus hypoplasia (MSH)
6. Cystic fibrosis (CF)
7. Maxillary sinus malignant tumours
 Local Intraoral
contraindications contraindications
 Grossly inadequate oral hygiene or inability to perform or
maintain appropriate oral hygiene
 Untreated periodontal disease of adjacent dentition
 Gross malocclusion and insufficient freeway space for
restoration
 Severe pathologic parafunctional habit (clenching or bruxism)
 Fulminant mucosal disease (desquamative mucosal disease,
erosive lichen planus)
 Severe Xerostomia
Decreased crown
height space
Poor bone density
Implant size
Decreased crown height space
 Poor bone density
• A literature review from 1981 to 2001 reveals the poorest
bone density may decrease the implant loading survival by an
average of 16 % and it has been reported as low as 40%.
• Bone strength =density
• Bone density= bone implant contact percent(BIC)
The cause of this can be related to various factors :
• Bone strength α density ( poor dense bone is 10 times
weaker than anterior mandible )
• Deficient osseous structure and absence of cortical plate on the
crest of the ridge.

• The thin labial cortex and ridge often being wide in posterior
region, implant has to relay on lateral BIC which is often
insignificant.
 BIC is least in D4 bone

Stress patterns migrate farther

towards the apex

As a result bone loss occurs

around the body rather than at
crest as in other denser bones

Greatest biomechanical elastic

modulus difference

Implant surgery often uses bone

compression rather than bone
extraction , often to
compensates for this
deficiencies
 IMPLANT SIZE
The ideal length of implant is directly related to

Implant success after loading is reduced in implant length less than 10 mm

4mm threaded root form implants should be at least 12mm in length when the
bone density is poor. This improves BIC .

Implants longer than 16 mm is not desired even in softest bone , since stress
transfer is not dissipated beyond this length.

Average implant: 12 to 16mm

Sinus grafting is required in conjunction with implant placement to gain adequate

bone height for implants for placing longer implants since the bone density is poor.
Classification of available bone

DIVISION A
—
DIVISION B
—
DIVISION C
—
DIVISION D
—
Misch and Judy in 1985
Division A (Abundant Bone)

>10-13mm height

>5mm width

>7mm mesio-distal length

<30 degrees angulation

C/I ratio <1

Division A is most often restored

with Division A root form implant
Division B (Barely sufficient bone)

 2.5-5mm width
 >10-13mm height
 >12mm mesio-distal length
 <20 angulation between implant body and
occlusal plane
 Crown/Implant ratio <1

 As the bone resorbs, the width of available bone first decreases at the expense of
the facial cortical plate. There is 25% decrease in bone width the first year, and
40% decrease in bone width within the first 1 to 3 years after tooth extraction.
Treatment options

•Modify by osteoplasty to permit the placement of root

form implants 4 mm
or greater in width.
 Insert a narrow Division B root form implant.
 Modify the existing Division B bone into Division A by
augmentation.
Unfavorable in: Width (C-w)
Height (C-h)
Angulation (C-a)
>30 degrees
C/I ratio >1

Division C (Compromised Bone)

(1) Osteoplasty
(2) Root form implants
(3) Subperiosteal implants
(4) Augmentation procedures
(5) Transosteal implants
Division D (Deficient Bone)

Severe atrophy
 Basal bone loss
 Flat maxilla
 Pencil thin mandible
D1: dense cortical bone
 D2: thick dense to porous cortical bone
on the crest and coarse trabecular bone
within.
 D3: thin porous cortical bone on crest
and fine trabecular bone within.
 D4: fine trabecular bone
 D5: immature, non-mineralized bone.
HISTORY OF SINUS SURGERY
1. 1970’S : TATUM ..autogenous rib bone onlay graft
2. 1974 : modified caldwell luc procedure for SA
grafting...crest was infractured to elevate sinus
membrane
3. 1975 : Lateral approach surgical technique & implant
simultaneously ( one piece ceramic implant )
4. 1981 : submerged titanium implants ...predicatble results
• 1974 to 1979 : autologus bone was the graft material
• 1980 : Tatum used synethetic bone in lateral approach
• 1980 : Boyne and James : autogenous bone
Treatment classification
for posterior maxilla
1984 : Misch ....based on amount of bone below the antrum.

1986 : expanded ...by including the available bone width.

1987 : included the technique of sinus floor elevation through implant osteotomy
before implant placement. ( out of 170 graft cases with 2 complications )

SA protocol : surgical approach + bone graft material + and timetable for healing
before prosthetic reconstruction

1995 : lateral dimension of the sinus cavity ...used to modify the healing period
protocol ( smaller width sinus form bone faster than larger width >15mm sinus )
 TECHNIQUE
1. Subantral option one(SA-1): conventional implant
placement
2. Subantral option two(SA-2): sinus lift and
simultaneous implant placement
3. Subantral option three(SA-3): sinus graft with
immediate or delayed endosteal implant placement
4. Subantral option four(SA-4): sinus graft healing and
extended delay of implant insertion
 Subantral option
one(SA-1):

• When sufficient bone height is present.

• Division B bone ....SA-1 treated with osteoplasty or augmentation

to increase the width of bone.

• The insertion of small diameter implants is not suggested in this

region due to.......
• Augmentation in width accomplished by bone spreading,
autogenous bone &/ appositional grafts.

• If less than 2.5 mm width ( C-w)...most predictable option is

onlay autologous bone grafts.

• Endosteal implants were allowed to heal for a period of 4 to 8

months followed by progressive bone loading.
A panoromic radiograph of posterior maxilla with abundant bone
height on right and left sides
Maxillary posterior quadrant is incised and reflected showing
available bone width
A guide is used to place the anterior implant 2mm from the
adjacent teeth
Sub antral option two : sinus
lift and simultaneous implant
placement
• Selected when 10 to 12mm of vertical bone is present (
2mm less than the minimum height in SA-1).

• SA-2 approach modifies the floor of the antrum...so no

pathological ....retrograde infection.
Incision Edentulous maxilla
and
reflection: Lateral relief incisions...5mm

One teeth beyond the edentulous site

Care for greater palatine artery..

Labial mucosa is pulled off rather than elevation...?

Check for available width of the bone >6mm.

 Osteotomy and sinus lift

• The implant osteotomy is prepared to the appropriate final

diameter short of the antral floor.
• Flat end or cup shaped osteotome is inserted and tapped firmly
in 0.5 to 1mm increments beyond the osteotomy until reaching
its final vertical position up to 2mm beyond the prepared implant
osteotomy
• Slow elevation less likely to tear the sinus

Surgical approach compresses

the bone below the antrum, Green stick type
fracture

• Elevates the unprepared bone and sinus membrane

over the broad based osteotome

if osteotome cannot proceed to the

desired osteotomy depth after tapping.....
Additional 1mm depth gained by osteotomy preparation
with rotary drills.
• Osteotome gets stuck....use extraction forceps

• If sinus infection occurs....BIC is prevented

• Attempts to feel the elevation of the membrane from 8mm deep

implant osteotomy may easily cause tear of membrane

to determine the success …...4 to 6 months later....bone over the

implant apex
 Subantral Option Three: Sinus Graft With Immediate Or
Delayed Endosteal Implant Placement

At least 5mm of vertical bone & sufficient width are present

Lateral maxillary wall approach....superior to residual ridge

Width is >5mm , implant inserted at the same time as sinus

agumentation or
delayed 2 or more months before implant insertion

When ridge is div B or C-w...onlay graft in conjunction with

sinus agumentation
 This height ( with adequate bone width and quality ) can be
considered sufficient to allow the primary stability of implants
placed at the same time of sinus graft procedure

 Will allow the use of alloplastic materials, because adequate

amount of bone may be harvested from the tuberosity to
augment the alloplastic component of graft.
 anesthesia

• Infiltration

• Second division of maxillary nerve block

• Two options of nerve block

1. HIGH POSTERIOR APPROACH

2. GREATER PALATINE FORAMEN APPROACH

Incision and flap reflection
Access window
 CT Scan...dimensions of the antrum

 Outline of lateral access window is scored on the bone with a

rotary handpiece under copious cooled sterile saline

 It is often easier to perform this step at 50,000 rpm even at

2000 rpm depending on the bone thickness

 No 6 round bur scratches the bone and designs the overall

window dimension.

 No 4 round bur which polishes away the bone within the groove
made by no 6 bur
 Inferior score line: placed 2 to 5 mm
above the level of antral floor i.e, 5-
10 mm from the crest.

If score line is too high: then ledge

above the sinus floor results in
dissection of membrane on the floor.

In case if available bone height is 10mm then sinus graft requires only 5
to 6mm of additional bone. This case lateral access is limited and inferior
score line is placed 1 to 2mm above the antral floor
 Superior score line : approx
8 to 10mm above the
inferior score line

Anterior score line : 5mm Distal score line: 15 mm in the

distal to anterior vertical wall edentulous posterior maxilla from

of the natrum the anterior limit of the window

usually in first molar region
• A larger access window offers many advantages : less stress on
the membrane during initial elevation and ease of additional
membrane elevation with instruments because of direct access
that facilitates graft placement.

• Excessive larger access window is not indicated, because the

outer bony wall of maxilla helps bone grow into sinus graft
material

• Corners should be rounded rather than angled.

 SINUS MEMBRANE ELEVATION
Flat end metal punch or
mallet....tapping at centre
followed by periphery

Short bladed surgical

curette..curved portion
against the window @ 2-4mm
Distance = 16 mm
• The top layer: collagen + antibiotic

• The second layer : sinus graft materials

• The bottom layer : autogenous bone

The top layer: collagen + antibiotic

 A resorbable collagen
membrane ( collatape) soaked in
parentral form of antibiotic
( Ancef 0.2ml, Cleocin 0.2 ml)
 Collagen acts as carrier
 Prevents sinus peroforation
The second layer : sinus graft materials

Various graft materials:

1. Autogenous bone
2. DFDB powder
3. Cortical fibers
4. FDBA
5. β – TCP
6. Xenograft hydroxyapatite (
bovine anorganic bone)
7. Calcium carbonates ( bio glass) &
8. combinations
The second layer : sinus graft materials (DFDB)

• Minute amount of osteoinductive material.... Bone volume <

original graft material placed

• Material resorbs more rapidly than bone formation.

• In addition, when placed in hypoxic conditions  fibrous or

cartilagenous tissue rather than bone.

• “ At the sinus graft consensus conference, high success rate

was reported for all materials and combinations, with the
exception of DFDB used alone”
The second layer : sinus graft materials (DFDB)

• In this graft material: DFDB+ microporous HA/ mineralised bone

allograft + PRP is used.

10 to 20 ml of whole blood is Centrifuged at 3400 to

drawn 5600 rpm
 The second layer : sinus graft materials

• The PRP is added to DFDB cortical fibers and osteoconductive

ceramic material is used in the intermediate layer.

• An antibiotic is also added when used for sinus grafts.

• Second layer ….. Microporous HA, inorganic
bovine bone, FDBA with 30% DFDB,PRP and
antibiotics.
• Should not be tight,
 The third layer

• Regional accelerated phenomenon

• Autologus bone graft

Regional accelerated phenomenon
• size of the antrum in the lower one third has been evaluated:

 Lateral to medial nasal wall < 10 mm ( small)

 average : 10 to 20 mm

 Large : > 20 mm

• Bone graft maturation takes 4 to 10 months, depending on the

type of graft material and size of the graft site.
 Autologus bone graft

• AUTOLOGOUS BONE

• TATUM...1970

• BOYNE AND JAMES...1980

• MISCH...Macaca fascicularis....iliac crest and tail boneost

SA3: implant placement
 Advantages of delaying implant placement:

 Individual rate of healing is assesed after 2 to 4 months....

 Sinus graft becomes infected with the implant in place....
 An implant in the middle of the graft impair the vascular bed...
 No chance for bone width augumentation...
 Denser the bone in delayed implant placement....
 Underfilled sinus graft...
 Not unusual to observe a craterlike formation in the center of
lateral window....
“ if overall time factor is patients concern...wait for 2 months to 4
months “
 SA region is first augumented ....later implant
placed

SA4: < 5mm available bone height

sinus SA 4 corresponds to a larger antrum

graft
healing
with Less autologous bone available at the harvesting
site...
delayed However in div D maxilla and atrophic

implant
maxilla...exposure may be upto zygomatic arch

insertion
Additional harvesting sites needed

Less vascular bed, low height , large antrum,

minimal autologous bon… long healing period
 Direct technique
• Advantages:
• When more than 4-5mm of bone grafting is
required
• Sinus membrane is directly visualized
• Easy access
• Disadvantages:
• More pain
• More post operative discomfort
• Time consuming
• Needs highly efficient surgeon
• More susceptible for infection
 Indirect techniques
• Advantages:
• Minimally invasive surgical procedure.
• The osteotomy is minimal being 1-3 mm deep and wide.
• Minimal instrumentation with closed graft deliver permits
a sterile technique.
• Simplicity of the procedure requires less time and
• expertise
• Disadvantages:
• Immediate implant loading is recommended after 3 months.
• Blind procedure (the sinus isn’t exposed).
• More chance of errors to occur
Floor dilatation technique
 Summers technique

Summers started floor dilatation of the sinus, thus

increasing the length of his implants.
Summers developed his technique, using the fractured sinus
floor as an osteotome and putting the grafting material through
the osteotome hole
 Balloon dilatation theory

This is an elegant minimum invasive technique, using an elastic

catheter. Forcing saline in the catheter, we swell the balloon and push
out the membrane.
Aside from its higher costs this technique is accessible and with
predictable results.
 Surgical protocol of sinus lifting
during extraction of upper molar.
• Raising the floor of the sinus during extraction is a
two-stage technique. It’s borrowed from classic
Summers’ technique, but it has limited indications.
• Raising the floor of the sinus through fracturing
the interroot septum of upper molar after its
extraction is possible, but relatively risky
technique.
 Hydropneumatic technique

The essence of this technique is that after the

osteotomy with the pilot bur, reaching 2 mm from the sinus
cavity, the hole is expanded to the sinus floor using
calibrated diamond tips
Then, using a tip, called “Trumpet” expands the hole, a cooling solution is
inserted from the piezosurgery unit and its hydrodynamic
pressure pushes out the Schneider membrane.
The grafting material is placed in the free space through the osteotome
hole with the help of the “trumpet” and then the implant
 Postop instructions
Do not disturb or touch the wounds.
Avoid rinsing or spitting for 2 days to allow blood clot
and graft material stabilization.
Don’t blow your nose at least 4weeks after surgery
Do not apply pressure with your tongue or fingers to
the grafted area, as the material is movable during the
initial healing.
Do not lift or pull on the lip to look at the sutures.
Do not smoke.
Keep good oral hygiene
 complications
• Membrane perforation/tearing
• Mucous retention cyst
• Bleeding
• Antral septa
• Incision line opening
• Neural injury
• Acute maxillary sinusitis
• Penetration of the implant apex into the sinus
Membrane tear
 conclusion
• The maxillary sinus lift has, over the last 30 years,
been established as an accepted standard for
treatment of the edentulous maxilla.
• Alternatives such as short implants, although shown to
be effective in the short term, lack long-term studies to
support routine use.
• While there are some relative contraindications for the
procedure, there are almost no absolute
contraindications. With preparation, education, and
experience, the maxillary sinus
augmentation/elevation graft is a procedure that
greatly benefits the patient, with a predictable
outcome.
 REFERENCES
• CONTEMPORARY IMPLANT DENTISTRY
CARL E.MISCH.
• ALTERNATIVE SINUS LIFT TECHNIQUES
Literature review.
• MAXILLARY SINUS AUGMENTATION. Tarun
Kumar A.B, Ullas Anand.
• SINUS LIFT PROCEDURES: AN OVERVIEW
OF CURRENT TECHNIQUES .Avichai Stern,
DDS*, James Green, DMD