This is a power point presentation on sinus floor elevation, describing the various techniques, biological aspects and clinical outcomes from a periodontist point of view. It also includes a brief review on the anatomy of maxillary sinus and management of complications.

1. SINUS LIFT
DARSHANAA A
FINAL YEAR PG

2. Contents
Introduction
History
Anatomy of the maxillary sinus
Treatment options for sinus floor elevation in the posterior maxilla
Graft materials
General indications for sinus floor elevation
Aspects of protrusion in the maxillary sinus
Aspects of implant length
3 layers of cortical bone at the second stage
One stage or two stage sinus lifting and implantation
Lateral sinus floor elevation
Sinus membrane elevation with grafting materials and immediate
or delayed implant placement
Sinus membrane elevation and simultaneous implant placement
without graft
Transcrestal sinus floor elevation
Concluding remarks
Alternative techniques in crestal approach sinus elevation
Indications for different sinus floor elevation techniques
Indications regarding the residual bone height
Contraindications
Management of complications
Conclusion

3. What causes lack of
sufficient bone height and
how was it managed?
Pneumatization and
atrophy of bone in
edentulous areas
A combination of long
and short implants
Implants mesial and distal
(tuberosity region) to the sinus
area and bridge placement
Cantilever bridge

4. •According to Branemark et al. and Weingart, based on human experiment and animal research, introducing
the tip of the implant into the maxillary (and nasal) sinus should not necessarily lead to problems for sinus
health.
•Increase in absolute bone height by augmenting the bottom of the sinus using autogenous iliac crest bone
graft was published by Boyne and Tatum in the late 1970s. This technique was called the sinus lift procedure

5. History
Maxillary sinus floor elevation was initially described by Tatum at an Alabama implant
conference in 1976 and subsequently published by Boyne in 1980.
Its need stemmed from the indispensability to restore the posterior maxilla using implants.
The procedure is one of the most common preprosthetic surgeries performed in dentistry today.
Since its first description, numerous articles have been published in this field regarding different
grafting materials, modifications to the classic technique, and parity between different
techniques.

6. Anatomy of the maxillary sinus
•Shape- a pyramid-shaped cavity; base- adjacent to the nasal
wall; apex- pointing to zygoma.
•Size- insignificant until eruption of permanent dentition;
average dimensions of adult sinus- 2.5–3.5 cm wide, 3.6–4.5
cm tall, and 3.8–4.5 cm deep; estimated volume of
approximately 12–15 cm.
•Extent- Anteriorly, extends to canine and premolar area.
sinus floor usually has its most inferior point near the first
molar region.
•The size of the sinus increases with age if the area is
edentulous. The extent of pneumatization varies from person
to person and from side to side; leaves the bony lateral and
occlusal alveolus paper-thin in the posterior maxilla.
•The maxillary sinus bony cavity lined with the sinus
membrane, known as the ‘schneiderian membrane’; consists
of ciliated epithelium like the rest of the respiratory tract;
continuous with, and connects to, the nasal epithelium
through the ostium in the middle meatus; has a thickness of
approximately 0.8 mm. Antral mucosa is thinner and less
vascular than nasal mucosa

7. The blood supply to the maxillary sinus is primarily derived from the posterior superior alveolar
artery and the infraorbital artery, both being branches of the maxillary artery.
There are significant anastomoses between these 2 arteries in the lateral antral wall. The greater
palatine artery also supplies the inferior portion of the sinus.
However, because the blood supplies to the maxillary sinus are from terminal branches of
peripheral vessels, significant hemorrhage during the sinus lift procedure is rare.
Nerve supply to the sinus is derived from the superior alveolar branch of the maxillary (V2)
division of the trigeminal nerve.

8. Treatment options for sinus floor
elevation in the posterior maxilla
•Boyne & James (1980), and later Kent & Block (1989), were the first to describe the technique of
lateral sinus floor elevation using autogenous bone harvested from the iliac crest and later
placement of implants. Lateral sinus augmentation with bone harvested from an intraoral site
was reported by Wood & Moore (1998).
•An alternative technique to increase the available bone height in the posterior maxilla, without
the use of grafting materials, has been described in 2004
•If minor augmentation is needed and the residual bone volume is adequate, transalveolar or
transcrestal sinus floor elevation can be used. The transcrestal sinus floor elevation procedure
can be performed with the addition of grafting materials inserted immediately before the
implant. This was described in 1999

9. Graft material
•the gold standard for grafting in sinus lift procedures has been the autogenous bone as a result
of their osteoinductive properties
•In cases where bilateral sinus grafting is planned and/or total augmentations are indicated, the
first choice of donor site has been the iliac crest. Large amounts of bone can be harvested from
this area. This procedure can therefore only be performed under general anesthesia.
•An alternative donor site mentioned in the literature is tibia head bone. Intraoral donor sites are
the chin, the coronoid process and the lateral buccal cortical bone plate of the mandible. These
intraoral donor sites have the advantage of being able to be performed under local anesthesia
and as an outpatient procedure. However, the quantity of bone to be harvested is limited.
•require an intraoral or extraoral donor site for bone harvesting and poses an increased risk of
complications and morbidity
•Thus, different grafting materials of biologic or synthetic origin, either alone or in combination
with autogenous bone grafts or locally harvested bone chips is commonly used.

10. General indications for sinus floor
elevation
•Implant placement in the premolar and/or molar
area in the maxilla with inadequate available
bone height in planned implant sites.
•Need for augmentation procedures dependent
on the number of missing posterior teeth.
•use of short implants in the posterior maxilla
have shown good result. modern micro-rough
surface implants in lengths of about 8–10 mm
and longer and of different brands are similarly
successful. the use of different sinus floor
elevation techniques should be considered when
< 8 mm of bone is available below the maxillary
sinus.

11. Aspects of protrusion in the maxillary
sinus
•In the Academy of Osseointegration Consensus Conference on sinus grafts, held in Boston (MA, USA)
in 1996, one of the consensus statements was that ‘implants placed into a grafted area should not
penetrate through the top of the graft, to avoid a nonbone covered tip of the implant in the sinus.’
•Johannsen et al (2013) – long -term follow-up studies on lateral sinus floor elevation with autogenous
bone grafts, evaluated using cone beam computed tomography, found that the implant tips often
protrude through the grafted area but are covered with a healthy sinus membrane.
•Jensen OT et al (1998) - Similar results were found for graftless lateral sinus floor elevation and
simultaneous implant placement, in which the apical part was covered with an asymptomatic and
normally thick sinus membrane.
•Abi Najim S et al (2013) - In a retrospective cohort study with a mean follow up of 10 years, 70
patients had 83 implants placed with conventional treatment, which penetrated the sinus floor
together with membrane perforation; however, there were no clinical or radiological signs of sinusitis
in any of the patients.
•Aparicio c (2008) - In addition, the experiences from zygomatic implants show few problems related
to the exposed implant surface per se.

12. Aspects of implant length
•to avoid perforation of membrane during the transcrestal sinus floor elevation procedure, the
membrane elevation height should not exceed 4 mm. Depending on the residual bone height,
an implant may therefore be 8–12 mm long.
•With the two-stage lateral sinus floor elevation technique, the height of the augmentation after
healing will dictate the length of the implants. Hence, the amount of grafting material used and
its properties with regard to resorption and shrinkage are of importance.
•With the graftless lateral sinus floor elevation technique, studies have shown a correlation
between bone formation and protruding implant length into the sinus. Therefore, it is
recommended to place implants of at least 10 mm in length to ensure an effective tenting effect.
•As a rule of thumb, if transcrestal sinus floor elevation is used the intended elevated height
should not exceed the height of the residual bone, while, with lateral sinus floor elevation, the
elevated height should exceed the height of the residual bone.

13. three layers of cortical bone at the
second stage
If implants are inserted at a second stage, 4 to 6 months after sinus lifting with autogenous
bone, there are three layers of cortical bone that might be encountered.
•The (thin) cortical bone of the alveolar process.
•The cortical bone of the former original sinus bottom, which still can be recognized on the
orthopantomogram.
•the new sinus floor or the former trap door.
Normally this last level is not reached with implants that have a length of 12 mm. The last-
mentioned cortical bone layer is not a very resistant one. If implant preparation is performed
too deeply, the burr will easily pass this last level

14. One stage or two stage sinus lifting and
implantation
Implantations can be performed simultaneously with sinus lifting (one-stage procedure) or at a
later stage (two-stage procedure).
A simultaneous sinus lifting and implantation procedure should only be performed if there is
sufficient bone quality and quantity to provide the implant of a firm basis for a good primary
stability.
This means that, if less than 4-5 mm vertical bone height is available, implant surgery should be
performed at a second stage, normally at least 4 months after sinus lifting with autogenous
bone (Raghoebar GM et al, 1997)

15. Lateral sinus floor elevation
Sinus membrane elevation with grafting materials
and immediate or delayed implant placement
INDICATIONS
•a posterior maxilla with inadequate subantral bone height for implant stability (≤ 5 mm).
•A prerequisite for a one-stage approach is that initial implant stability can be accomplished.

16. SURGICAL PROCEDURE

17. CLINICAL OUTCOMES
IMPLANT SURVIVAL
•Aghaloo TL et al (2007) - greatest survival rate - autogenous bone grafts and with xenogenic bone grafts (resonance
frequency analysis = 95%); increased bone formation and higher survival rate - When membranes are used to cover
the lateral wall of the augmented sinus; higher survival rates - implants with a microrough surface
•The implant failure rate is usually higher during the first year of function
•the annual implant failure rate was reported to be 3.48%, with a 3-year survival rate of 90.1%. (Pjetturson BE et al
(2008)

18. 5,128 implants placed after lateral sinus floor elevation,
with follow-up times ranging from 10 to 102 months,
were analyzed. Implant survival was 92% for those
placed in autogenous and composite grafts, 93.3% for
those placed in allogeneic/nonautogenous and
autogenous/ composite grafts, 81% for those placed in
alloplast and alloplast/xenograft materials and 95.6% for
those placed in xenograft materials alone
In a prospective study using composite grafts with either autogenous bone and deproteinized bovine bone mineral, or
autogenous bone together with beta-tricalcium phosphate, the 5-year survival rate was 98% (Bonstein MM et al 2008)
no statistical difference in implant survival or success for different grafting materials, including autogenous bone, or
differences in results comparing the two methods (Del Fabbro M et al 2008)
In a study comparing particulated bone in a two-stage procedure with bone blocks and simultaneous implant
placement, the results favored the two-stage procedure after 1 year of functional loading (Wannfors K et al, 2000)

19. MARGINAL BONE RESPONSES
marginal bone loss was higher in grafted patients and it took a longer time to reach the steady state compared
with implants placed in pristine bone. smokers lost more implants and more marginal bone during the 3- to 10-
year follow up time compared with nonsmokers. (Mordenfeld A et al 2014)
LONG-TERM STABILITY OF BONE GRAFT HEIGHT
In the past 10 years, Jensen et al. (2012) have investigated the healing mechanism of autogenous bone and
deproteinized bovine bone mineral in different mixtures in an experimental minipig model. These studies all
showed that the former provides strong activationvof bone formation as well as fast resorption during the early
healing phase, the bone height gained can be reduced by as much as 50% by this remodeling. It also offers the
possibility of a shorter healing time compared with the latter. The latter, as a result of the minimal substitution
rate it provides better stability of the graft height.
Autogenous bone, beta-tricalcium phosphate and surgical plaster have a higher resorption rate than other
materials (dasmah A et al 2012)
In a prospective study, 80/20 mixture of BioOss and autogenous bone, the graft height was minimally affected
(10%) after 2 years (Hallman M et al 2002)
In one recently published study, BoneCeramic and BioOss were used and the height of the graft measured on
panoramic radiography after 5 years showed no statistical difference in reduction (4 and 5%, respectively).
Most of the height reduction occurred during the first 1–2 years. (Mordenfeld et al 2016)

20. COMPLICATIONS
penetration of the membrane and migration of the graft material into the sinus antrum. An
incidence of membrane perforation of 0–25% is reported in the literature, but very few with
subsequent complications. (Chiapasco M et al 2009)
graft resorption and decrease of the anticipated graft volume, graft migration and
sequestration, and may be more prone to infections compared with bone substitutes when
autogenous bone or resorbable materials are used
early implant failure during immediate implant placement.
postoperative infections, excessive bleeding and damage of the infraorbital nerve.
Implant loss (implant survival) and marginal bone resorption. Implant survival is probably 2–3%
lower for implants placed in augmented bone compared with implants placed in ordinary bone.
(Nedir R et al 2016)

21. BIOLOGIC AND HISTOLOGIC ASPECTS
in a relatively early phase after grafting, autogenous
bone shows the highest total bone-volume values.
Interestingly, the variation in levels of total bone
volume, observed at early phases according to the
different grafting material used, dimished with
time. After 9 months no statistically significant
differences in total bone volume were detected
between the various grafting materials. The authors
concluded, from a biological point of view, that, if a
shorter graft-healing time and/or a shorter loading
protocol is needed, the use of autogenous bone
graft is advantageous
In many animal studies of different grafting materials, autogenous bone generally promotes the best bone
formation.
In histomorphometric studies comparing simultaneous implant placement with the staged approach, the results
were in favor of the staged approach (Janner SF 2011)

22. Sinus membrane elevation and simultaneous
implant placement without graft
INDICATIONS
•Graftless lateral sinus floor elevation is indicated when the amount of residual bone height in
the alveolar process below the maxillary sinus floor is inadequate for optimal stability when
inserting dental implants using a standard technique and/or by the transcrestal sinus floor
elevation technique
•As the graftless lateral sinus floor elevation technique utilizes simultaneous implant placement
and tenting of the sinus membrane, the possibility of achieving sufficient primary implant
stability should be the decisive factor in selection of this technique. The stability of the primary
implant may vary depending on bone height and width, as well as on bone density and type of
implant used.

23. SURGICAL TECHNIQUE

24. OUTCOMES
IMPLANT SURVIVAL
Several authors have documented that the mere elevation of the maxillary sinus membrane at
the time of implant insertion, with the creation of a void space in which blood-clot formation
occurred, resulted in successful bone reformation and implant survival.
Cricchio et al. (2011) reported that 96 maxillary sinus membrane-elevation procedures and the
simultaneous placement of 239 oxidized implants, without bone grafts or bone substitutes,
resulted in predictable bone formation with a high implant-survival rate of 98.7% during a
follow-up period of 1–6 years after functional loading.
Riben & Thor (2016) evaluated 83 implants placed according to 53 sinus membrane-elevation
procedures and reported a survival rate of 94.3% after a mean follow-up time of 4.6 years
Ellegard et al. (2006) reported on sinus membrane lift and simultaneous implant therapy in 68
periodontally compromised patients. The 5-year follow-up results showed an implant survival
rate of 90% despite compromised periodontal health in all of the patients and the fact that more
than 60% of the patients were smokers at the time of implant surgery

25. INTRASINUS RESPONSES BASED ON RADIOGRAPHIC MEASUREMENTS OR AUGMENTED NEW-
BONE STABILITY
•Cricchio et al. (2011) found intrasinus bone formation at all implant sites, which amounted to,
on average, 5.3 mm at 6 months after implant surgery. The amount of bone mineralization, as
evaluated in periapical radiographs, seemed to increase with time. In general, new bone was
more easily distinguished at time points of 1 year and later than at earlier time points. There
was a positive correlation between the amount of bone formation and the implant length in the
maxillary sinus (i.e. the higher the sinus membrane elevation, the more bone created)
•Thor et al. (2007) found more bone in sites with only 2.0–5.5 mm of residual bone than in sites
with more bone and drew the conclusion that this was a result of the longer implant length
present in sinuses with less residual bone
•In a split-mouth design, Borges et al. (2011) compared sinus membrane elevation without (test
side) and with the use of autogenous bone graft. They found no statistically significant
differences in newbone formation between the two groups. A significant, positive correlation
was found between the protruded implant length/bone gain.

26. COMPLICATIONS
Sinus membrane perforation is an intraoperative complication observed with the graftless
lateral sinus floor elevation technique. However, although an intact membrane is desirable,
perforation does not seem to prevent bone formation
In a study on 239 implants placed according to 96 elevation procedures, six minor perforations
(< 5 mm) and five major perforations (> 5 mm) occurred. Of the 25 implants inserted in the
sinuses with membrane perforation, only one failed, giving a survival rate of 96% for implants in
perforated sites. The six minor perforations were left to heal, while the five major perforations
were sutured to the adjacent bone wall. Bone formation was observed in all perforated sites.
This was confirmed in experimental studies, minor membrane perforation seemed to have no
consequence on the NB (Crichio et al 2009)
Early exposure of the cover screw is another complication observed with this technique,
particularly in situations with minimal height of the residual crest. However, exposure of the
cover screw does not seem to lead to increased risk for implant failure, although some marginal
bone resorption can be expected (Crichio et al 2014)

27. BIOLOGIC AND HISTOLOGIC ASPECTS
•Boyne et al. (1993) showed, in a study on primates, that sinus membrane elevation and implant insertion with the
apical part protruding in the sinus cavity under the elevated mucosa, results in spontaneous bone formation
•In an experimental study by Palma et al., (2006) machined and oxidized implants were placed in conjunction with
sinus membrane elevation using the replaceable bone-window technique. One sinus was filled with autogenous
bone grafts and served as a control for the elevated side where no grafts were used. Histology was performed after 6
months of healing and showed bone formation around the implants at both sides with no apparent differences. The
lifted sinus membrane lined the new bone and the apex of the implant with no signs of inflammatory infiltrates or
irritation. The surface-modified oxidized implants showed more direct bone–implant contacts than did machined
implants, irrespective of treatment.
osteogenic potential of the maxillary sinus membrane on bone formation during the early healing phase.
•On the other hand, in a study on primates, Scala et al. (2012) reported that the sinus membrane is not involved in
new-bone formation during the first 20 days after surgery. They found that new bone originates from the sinus wall
and from septa
•Similar conclusions have been outlined by Jungner et al., (2014) in a histologic and immunohistochemical study on
early bone-formation events in primates after membrane elevation in the maxillary sinus
•In a clinical histologic study, Johansson et al. (2013) found no differences when comparing lateral sinus floor
elevation, with and without autogenous bone grafts, regarding bone formation and bone–implant contacts

28. Transcrestal sinus floor elevation
INDICATIONS
suitable for single tooth gaps with sufficient bone width
ADVANTAGES
less trauma, shorter operation time and less postoperative morbidity. Moreover, the implants
are commonly placed simultaneously with the transcrestal sinus floor elevation procedure.

29. SURGICAL TECHNIQUE

30. CLINICAL OUTCOMES
Review comprising 19 studies, the survival rate of
posterior maxillary implants when using the
osteotome technique was investigated, showed an
implant survival rate of 95.8% after 5 years. a
statistically significant difference between implants
installed in bone in which the residual bone height
was < 5 mm (92.7%) compared with > 5 mm (96.9%).
The authors could see no significant difference when
grafting material was added compared with lifting the
membrane without additional filler material.
if an intact chamber is created around the implant, blood alone would be sufficient for bone healing
(Lundgren et al)
These findings were confirmed in an experimental study (Palma VC et al 2006)
in a clinical/ histological study, no differences were found between grafted and nongrafted implants regarding
the amount of bone and bone–implant contacts (Johansson LA et al 2013)
technique sensitive; up to 28% of the membranes may rupture during elevation (Testori T et al, 2012), a
secluded blood chamber cannot be expected if there is a membrane tear.

31. in a review comprising 25 papers, that the transcrestal approach had a 97.2% survival rate of the implants
followed up to 6 years compared with 93.7% for the lateral window approach

32. BIOLOGIC/HISTOLOGIC ASPECTS OF TRANSCRESTAL SINUS FLOOR ELEVATION
no experimental studies on the transcrestal sinus floor elevation technique per se have been
published.
However, experimental and clinical studies have shown bone formation after elevation of the
sinus membrane with implants or other space-making devices when using a lateral approach
(Cricchio G et al 2009)

33. Concluding remarks
•Lateral antrostomy allows for a greater amount of bone augmentation to the atrophic maxilla
but requires a larger surgical access.
•The crestal approach is minimally invasive but permits only a limited amount of augmentation.
•Therefore, practitioners should select the type of procedure appropriate to the particular clinical
needs.
•In addition, all relevant anatomic structures in the vicinity should be respected to minimize
surgical complications

34. Alternative techniques in crestal
approach sinus elevation
SINUS LIFT BY DILATATION
using the elasticity of the bone, Summers started floor dilatation of the sinus, thus increasing
the length of his implants.
The disadvantages of this technique are its limited indications - the height lack of 1-2 mm and
the absence of direct visual control of the state of the membrane

35. SUMMERS’ OSTEOTOME TECHNIQUE
•Summers developed his technique, using the fractured
sinus floor as an osteotome and putting the grafting
material throurh the osteotome hole
MODIFIED SUMMERS TECHNIQUE
•Later, Summers’ technique was modified and the original
concave, cutting osteotomes were replaced by convex and
rounded ones.
•The main difference of the modified osteotome
technique, is that we don’t fracture a fragment in the
sinus floor. The rounded osteotoms permit safely
comprimition of bone after preparing the pilot hole,
expanding of the hole, extrusion of the graft in the sinus
cavity and placing of the implant

36. BALOON SINUS LIFT TECHNIQUE
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.
Additional advantage of this method is that we know in
advance the free space volume and the graft material
volume we need

37. 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
THE HYDROPNEUMATIC SINUSLIFT
a crestal access technique, introduced in 2008 by Troedhan,
A. Kurrek, M. Wainwright.
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” , with a diameter equal
to the diameter of the last instrument that 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.

38. Indications for different sinus floor
elevation techniques
The type of sinus floor elevation technique selected to be discussed with the patient, is mainly
based on
•residual vertical bone height
•marginal bone width
•local intrasinus anatomy
•number of teeth to be replaced
•surgical training and experience

39. cone beam computed tomography is the preferred radiographic technique as it provides high
quality images in three dimensions using low doses of irradiation compared with conventional
computed tomography. They also help in revealing information useful for the selection of
technique
Apart from pathology, the thickness of the lateral bone wall, presence of septa, flat vs. oblique
sinus floor, status of the Schneiderian membrane and width of the sinus, and virtual implants
can be placed. the amount of grafting material can be estimated. allow for measurements of
bone density, which can be used to estimate the primary stability

40. Indications regarding the residual bone height
•It is proposed that a transcrestal sinus floor elevation
approach is considered as the first choice for single
tooth gaps in situations with sufficient width for implant
placement and a minimal residual bone height of 5 mm.
•Lateral sinus floor elevation with simultaneous implant
placement, with or without graft, is indicated when a
minimal residual bone height of 3 mm is available and
when one or several teeth are to be replaced.
•In situations with a residual bone height of < 3 mm, a
lateral sinus floor elevation technique with grafting in a
separate session, followed by implant placement after
graft healing, should be the technique of choice.
With regard to the time of implant placement, a one-
stage procedure is preferred provided that sufficient
primary stability can be achieved

41. However, the sinus floor elevation technique should always aim to achieve sufficient primary
stability of the implants at placement to allow for optimal rahabilitation conditions.
Concerning impact of implant length, if 10 mm is recommended as the minimal length of
implant in sinus floor elevation and the maximal recommended elevation height in transcrestal
sinus floor elevation should not exceed 3–4 mm, the recommended residual bone height should
be at least 6 mm. For the same implant length, a lateral sinus floor elevation with simultaneous
placement of implants should have a residual bone height of 3–5 mm, as the minimal elevation
height should exceed 3–4 mm to allow for new-bone formation under the elevated membrane.
In the situation with a staged procedure the amount of residual bone is not of importance as the
appropriate degree of implant stability will be achieved from the new bone formed from the
healed graft.

42. Contraindications
ABSOLUTE CONTRAINDICATION
•previous sinus surgery like the Caldwell Luc operation. This type of surgery often leaves scar
tissue instead of the normal ciliated mucosa lining of the maxillary sinus. Apart from the medical
patient history, this condition is often recognizable on the radiograph. On an orthopantomogram
this condition often shows as a radiographically vague sinus structure, which indicates abnormal
local anatomy.
•Maxillary sinus diseases such as tumors or Chronic polypous sinusitis, strong allergic
conditions comprise a contraindication for sinus lifting. They may be recognized on an
orthopantomogram. Computer tomography, however, gives a much better impression of the
actual maxillary sinus condition.

43. RELATIVE CONTRAINDICATION
•the contours of dental roots are often recognized in the floor of the maxillary sinus. Even many
months after extraction these root shapes remain. Preparing the maxillary mucosa from these
structures without tearing the membrane can be extremely difficult. This should be kept in mind
when planning sinus lifting soon after extraction of premolars and molars.
•extremely narrow sinus. The maxillary sinus is rarely that narrow that the trap door does not
have sufficient space to be turned up. Unfortunately, this condition can only be recognized on a
coronal computed tomographic scan. If the condition is detected preoperatively, the trap door
can be made less high utilizing a wide horizontal trap door preparation.
•presence of Underwood’s septa or severe sinus floor convolutions. Most septa are seen in
young people and are believed to strengthen the structure of that specific part of the scull. They
normally run transversally through the bottom of the sinus and can be quite high. This means
that if an usual trap door preparation is made, it will block the door and prevent it from being
turned inward and upward.

44. There are three ways to get around this underwood’s septa.
•make an anthrostomy instead of a door. In this way the Schneiderian membrane can be
prepared upward, but does not provide the bony trap door as a new sinus floor.
•make the trap door only on the medial sinus lob (this means mesially of the septum). This is
only indicated if implant surgery is planned in that specific area of the maxilla.
•Make a scalloped trap door. This can only be done in the septum and does not extend too far
cranially

45. Management of complications
ANTRAL PSEUDOCYSTS - can be thoroughly drained
once the osteotomy has been prepared and before
membrane elevation and graft placement. Patients
with larger or more generalized pseudocysts should
be referred to an otolaryngologist for evaluation
before considering augmentation procedures
SINUSITIS - If dentally related, the source of such
infections should be removed and an antibiotic
should be initiated. Patients presenting with acute or
chronic sinusitis that is not dentally related should be
referred to the appropriate medical professional for
assessment and treatment before sinus
augmentation.

46. PERFORATION OF SCHNIDERIAN MEMBRANE - attempt to elevate the membrane around the perforation. This
may require expansion of the osteotomy site. In case of a large perforation, this may not be possible. Small
perforations can be repaired by placing a resorbable collagen membrane over the perforated area after it has
been elevated and before the addition of bone graft. Larger perforations are more common in areas of
challenging anatomy and are more difficult to deal with. They are usually repaired using larger resorbable
membranes fixed to the superior aspect of the osteotomy window with bone tacks before bone augmentation

47. INTRAOPERATIVE BLEEDING- can be controlled by
placement of the bone graft, which exerts pressure on the
wound. However, significant bleeding may be challenging
to manage as the bone graft particles may wash out. If a
vessel in the lateral wall of bone is noted, a crush injury to
the vessel can stop the bleeding.
POSTOPERATIVE BLEEDING- sometimes occur in the form
of a nose bleed. Patients should be advised of this
possibility and be instructed not to blow their nose for at
least 5 days after the operation. Postoperative bleeding
from the surgical site is rare and can be avoided through
adequate primary closure and thorough suturing.
POSTOPERATIVE SWELLING AND HEMATOMA- a steroid
may be used and an NSAID is highly recommended.
Patients with such conditions should be carefully
monitored.
POSTOPERATIVE INFECTIONS - use of appropriate
antibiotics before and after the surgical procedure is
standard and may reduce infection risk. If antibiotic
therapy is not effective, incision and drainage should be
performed. If the infection cannot be resolved, then a
mucoperiosteal flap should be raised, the graft removed
and the site thoroughly irrigated.

48. conclusion
Although the cIinicaI resuIts of recent publications
are promising, it should be kept in mind that this
type of delicate surgery should only be planned after
careful investigation and performed by experienced
surgeons.

49. References
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