This document provides an overview of sinus grafting procedures for dental implants. It defines maxillary sinus grafting as a procedure to increase bone thickness in the posterior maxilla when there is insufficient bone for dental implants. The document describes the surgical anatomy of the maxillary sinus and the conventional lateral window approach for sinus grafting. This involves raising a bone window to access the sinus membrane, elevating the membrane to increase bone height, then grafting and often simultaneously placing dental implants. The document outlines indications, contraindications and postoperative care for sinus grafting.

1. D R . S A N G E E T A P O R I Y A
M D S 2 N D Y E A R P G S T U D E N T
D E P T . O F P R O S T H O D O N T I C S
M G S D C
SINUS GRAFTING FOR
DENTAL IMPLANTS

2. CONTENT
 Introduction
 Definition
 Surgical Anatomy of Maxillary Sinus
 Sinus Lift
 Indications
 Contraindications
 Pre- & post-medication
 Coventional Technique
Lateral approach
crestal approach
 Complications
 Summary
 References

3. INTRODUCTION
• Paranasal Sinuses (PNS)-
air containing bony spaces around the nasal cavity

4. Definition
“ Maxillary sinus is the pneumatic space that is lodged inside the body of
the maxilla and that communicates with the environment by way of the
middle nasal meatus and the nasal vestibule.”
( Ref: Orban’s Oral Histology – 10th Ed.)

5. Why called 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

6. DEVELOPMENT
Maxillary sinus is the first of the PNS to
develop
4th week I.U.L. – dorsal portion of 1st
Pharyngeal arch forms the Maxillary process

7.  In its development Sinus is:
• Tubular at birth
• Ovoid in childhood
• Pyramidal in adulthood

9. Surgical Anatomy of Maxillary Sinus
 Largest of the PNS
 Pyramidal shaped cavity within the body
of the Maxilla

10.  Pyramidal in
shape –
base :lateral
nasal wall;
apex : root of
the zygoma

11. ROOF OF THE ANTRUM
 Formed by floor of the orbit and is transversed by the
infraorbital nerves.It is flat and slopes slightly
anteriorly and laterally

12. 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

13. ANTERIOR WALL
 Formed by the facial surface of the maxilla.
 Canine fossa is an important structure of this wall

14. POSTERIOR WALL
 Formed by sphenomaxillary wall.
 A thin plate of bone separate the antral cavity from
the infratemporal fossa.

15. MEDIAL WALL
 Bounded by the Lateral wall of nasal cavity
 The opening of the sinus is closer to the roof and
thus at a higher level than the floor.

16. LATERAL WALL
 Related to zygoma and cheek.

17.  Ostium
• situated high up in medial wall and opens into the
middle meatus of the nose in the lower part of the
hiatus semilunaris.
• Poorly placed from the point of view of free
drainage.
• An accessory ostium may also present behind the
main ostium in 30% cases.

18.  Arterial supply-
 Branch of third part of
maxillary artery
(pterygopalatine part)
 1. PSA
 2. IOA
 3. GPA.

19.  Venous drainage
 1.Anteriorly- Facial vein
 2.Posteriory- Pterygoid venous plexus

20.  Nerve supply
1.ASA
2. MSA
3. PSA
4. IO

21.  Lymph drainage
1. Submandibular lymph nodes
2. Deep cervical lymph node
3. Retro pharyngeal lymph nodes

22. About membrane
 The maxillary sinus bony cavity lined with the sinus
membrane, is also known as the ‘schneiderian
membrane.’ This membrane consists of ciliated
epithelium like the rest of the respiratory tract.
 It is continuous with, and connects to, the nasal
epithelium through the ostium in the middle meatus.
The membrane has a thickness of approximately 0.8
mm.

23. Functions
 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
 Mucus production and storage
 Limit extent of facial injury from trauma
 Provides thermal insulation to important tissues
 Serves as accessory olfactory organs.

24. What is a Sinus Lift?
When there's not enough bone for
an implant,
a sinus lift is needed

25. REQUIREMENT??
 After the loss of the Max M, PM,
the maxillary sinus expands and
lowers down (‘pneumatization’),
resulting in reduced subantral
bone height, which is inadequate
to insert adequately long implants.
 Further, long-time edentulism
leads to vertical ridge resorption,
which further deteriorates the
situation for the insertion of long
implants and also increases the
crown–implant height ratio.

26. 1st performed-whom &when?
 The first sinus graft was performed by Dr Hilt Tatum
in February 1975 in Lee County Hospital in Opelika,
Alabama.
 This was followed by the placement and successful
restoration of two endosteal implants.

27.  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).
When to do?

28.  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
When not to perform

29.  Antibiotics-
Amoxicillin–clavulanic acid – BD-5 days
 Analgesics
 Codeine (Tab.Tylenol 3)
 Anti anxiety/sedatives
Alprazolam (Tab. Alprax, or Valium, 2 mg) :when
required
 Corticosteroids
Dexamethasone (Tab.Decadron, 4 mg):when required
Pre- and post-medication

30.  Multivitamins
Vitamin B complex + zinc + Lactobacillus
combination(Cap. BC-Z-LB)
 Antibacterial oral rinse
Chlorhexidine gluconate 0.12%
 Cryotherapy
Ice or cold dressings on the face and cold oral liquids
used for 24–48 h after sinus graft surgery.
 Hot fermentations

31. How is the sinus lift procedure performed?
A sinus lift increases the thickness of bone

32.  Lateral approach for sinus grafting
(A) Lateral and (B) cross-sectional views of posterior maxilla showing sinus cavity
(sinus antrum) and subantral residual bone, which is inadequate in height to
insert adequately long implants.
SINUS CAVITY
Sinus membrane
Conventional surgical techniques

33. Fig (A and B) A mid-crestal incision along with two facial vertical extensions are
made and a trapezoidal mucoperiosteal flap is elevated to expose the lateral wall
of the maxillary sinus.

34. Fig (A and B) A rectangular or oval osseous window is carefully prepared on the
lateral wall of the sinus using a large round diamond bur to expose the sinus
membrane without perforating it.

35. Fig (A and B) Once the osteotomy is completed to expose the sinus membrane, the
bony window can gently be tapped with the back of the mouth mirror handle to
visualize the complete preparation and to break the small and thin bony bridges still
left between window bone and surrounding bone.

36. Fig (A and B) The schneiderian membrane is carefully elevated to the desired
height using a special set of sinus curettes.

37. Fig (A–C) The elevated sinus floor is grafted through the lateral window using bone
substitutes mixed with autogenous bone. A resorbable collagen membrane can be
placed under the elevated sinus membrane before filling it with the graft as it
protects the sinus membrane from being torn by the graft particles. (D) A parenteral
antibiotic like clindamycin can also be mixed with the graft to prevent any
postoperative infection

38. Fig Once the elevated sinus floor has been loosely filled with the graft, the implant
osteotomies are prepared in the usual fashion and implants are inserted. (A–D) The
rest of the sinus is further grafted until it is all loosely packed with the graft. If
subantral bone height is inadequate to stabilize the immediately inserted implants,
the surgeon can only graft the sinus and choose to go for delayed implant placement
when the new bone has regenerated in the grafted sinus floor after 6–8 months.

39. Fig (A and B) A resorbable collagen barrier membrane can be placed to cover the
lateral window to prevent soft tissue ingression into the grafted sinus. (C and D) Flap
is sutured back with a primary closure. Implants are uncovered and restored after
new bone formation has occurred in the entire grafted sinus in 6–8 months.

40. Simultaneous or delayed
Implant placement
one-stage lateral
antrostomy-
Implant with graft.
Sufficient residual bone.
two-stage lateral antrostomy-
Implant placement 6-12
months after grafting.
subantral bone height<4mm.

41.  Graft materials for the sinus grafting-
 Autogenous bone remains the gold standard.
 Autogenous donor sites –
Iliac crest,
chin,
anterior ramus,
and tuberosity.
 Alternate, FDBG +Bio-oss/TCP
 +PRF=Amount,quality,and pace

42.  Advances and modifications in the lateral
approach of sinus lifting:
Lateral approach of sinus lifting using piezosurgery
unit:-
Fig (A) Piezosurgery unit , sinus lift kit containing special tips for lateral window
preparation and (B) sinus membrane elevation.

43. Fig. Application of
the various piezo
tips: SL1 Tip is a
diamond coated tip
for vestibular bone
window cut and for
attenuation of sharp
angles.(A and B) A
rectangular window
can easily be scored
using this tip,
without tearing the
sinus membrane

44. Fig. SL2 Tip is a diamond-coated ball tip for smoothing the vestibular bone window;
precise osteoplasty using this tip at the prepared osteotomy corners to remove the
sharp bony edges, reduces the chances of membrane tear during elevation. (C and D)
Ball diameter: 1.5 mm, laser marked every 2 mm. (E and F) SL3 Tip is a flat-ended
noncutting tip used for detaching the Schneiderian membrane from the window
edge. (G and H) SL4 Tip is a noncutting spatula, oriented at 90°, used for detaching
the Schneiderian membrane inside the sinus.

45. Fig (I and J) SL5 Tip is a noncutting spatula, oriented at ±135°, used for detaching
the Schneiderian membrane inside the sinus and for removing anatomical structures.
(Courtesy: Dr Pierre Marin, Implantologist–private practice, Bordeaux, France)

46. Lateral approach of sinus lifting using DASK:
Dentium Advanced Sinus Kit (DASK)
Step 1 – scoring the lateral osseous window:-
1. Wall-off technique
2. Grind-out technique
Step 2 – sinus membrane elevation
Step 3 – osteotomy preparation for the implant
Step 4 – grafting of the elevated sinus floor and implant
placement

47. Fig 18. (A–C) Wall-off technique-
After elevating the mucoperiosteal flap to expose the ridge and lateral wall of the
sinus, a special DASK drill attached to a rotary handpiece is used to carefully score a
circular osseous window at the lateral osseous wall of the sinus, without any tear to
the underlying Schneiderian membrane. Once the drill has reached the membrane,
the scored round bony wall is carefully removed (wall-off) from the
underlying sinus membrane and the membrane is elevated using a special set of sinus
curettes

48.  Fig 18.42╇ (A and B) Grind-out technique- A
Fig . (A and B) Grind-out technique-
A special large coarse diamond DASK drill is used to grind the lateral wall of the
sinus with a sweeping action to reach the underlying sinus membrane. Once the
sinus membrane is exposed, it is elevated using a special set of sinus curettes.

49. Step 2 – sinus membrane elevation
Fig . (A) After exposing the sinus membrane either with wall-off or grind-out
technique, a special DASK tip is used to detach the membrane from
the prepared window margins. (B) Once the membrane has successfully been
detached all around from the prepared osseous window, a special set
of curettes (sinus elevators) is used to elevate the Schneiderian membrane to the
desired height.

50. Step 3 – osteotomy preparation for the
implant
Fig . (A and B) After the sinus membrane has been elevated to the desired height, the
osteotomy for the implant is prepared from the crestal approach using drills of the
particular implant system.

51. Step 4 – grafting of the elevated sinus floor and
implant placement
Fig . (A–D) Once the implant osteotomy has been prepared, the elevated sinus floor is grafted
through the lateral window using bone graft and the implant is inserted. Usually the implant is
placed and left for submerged healing but in selective cases where the inserted implant has
achieved adequate initial stability (more than 30 Ncm) and the force factors are minimum, the
implant can be left for open healing by placing the long healing abutment on top of the implant.

52. o Disadvantages of the lateral approach:
1. Large flap elevation reduce blood to lateral wall
of sinus.
2. Difficult access with reduced mouth opening.
3. More chances of sinus rupture and postoperative
complication, compared to the subcrestal
approach.
4. Large amount of graft required.
5. Barrier membrane needed to cover window.

53.  Crestal (osteotome) approach/internal sinus-
lift technique/Summer’s osteotome
technique

54. Sinus
membrane
Mucosa Subantral residual bone
Fig. (A ) cross-sectional view of posterior edentulous maxilla showing limited
subantral bone height, which is not sufficient for adequately long implant placement.
(B) Preoperative radiograph shows 8 mm subantral bone height

55. Buccal flap Sinus floor
Lateral wall of sinus Subantral bone
6-8mm
Palatal flap
Medial wall of sinus
Sinus membrane
Fig . (A and B) Mid-crestal incision is made and flaps are elevated to expose the
ridge crest.

56. Fig. (A–D) Osteotomy for the implant is prepared in the usual fashion using all the
drills 2.0 mm short of sinus floor, which can be verified with the dental radiographs
with the drill in place.

57. Fig .(A–D) Once the implant osteotomy is completely prepared 2 mm short of the sinus floor, an
appropriate sized sinus-lifting osteotome is inserted and carefully tapped to fracture up the
sinus floor, and also lift up the Schneiderian membrane. After fracturing the bony floor of the
sinus, a collagen membrane or collagen plug can be inserted into the osteotomy before further
lifting the sinus membrane. It prevents the inadvertent rupture of the delicate Schneiderian
membrane. After achieving the required height of sinus elevation, a blunt implant probe can be
inserted to evaluate the height of the sinus elevation that has been achieved and also to check if
any rupture have occurred in the membrane.

58. Fig. (A and B) The flap is sutured back with primary closure. (C and D) The implant
is exposed and restored after new bone regeneration has occurred in the grafted
sinus in 4–6 months

59. o Advantages of the crestal
approach/Summer’s osteotome technique
1. Less invasive.
2. Improves maxillary bone density, allows greater
initial stability of implants.
3. Less graft required .
4. No barrier membrane required.
5. Limited flap elevation required.

60. o Disadvantages of the crestal
approach/Summer’s osteotome technique
1. Initial implant stability unproven, if the residual
bone height is less than 6 mm.
2. Limited height of sinus elevation compared to the
lateral approach.
3. Higher chance of misaligning the long axis of the
osteotome during osteotomy.
4. Tapping can cause mental trauma to the patient.

61. Recent advancements and modifications
in the crestal approach of the sinus lifting
Bicortical engagement without sinus grafting:
If the subantral residual bone is more than 6–8 mm
in height and more than 10 mm in width, a large
diameter (6–7 mm) and short length (7–9 mm)
implant can be inserted with bicortical engagement
(in the crest bone as well as into the antral floor)

62. Fig. (A) Residual subantral bone height, which is insufficient for ideal length implant
placement. (B) A pilot drill/Lindemann drill is used to prepare the implant osteotomy 1–2 mm
short of sinus floor.
Fig .(A) All the osteotomy widening drills are used to the same depth. (B) A
countersinking drill can be used to submerge the implant 1 mm apical to the ridge
crest.

63. Fig. The rest of the sinus floor either can be ground using DASK or fractured up
using the osteotome. (A and B) Further, the implant is inserted to engage its apex
into the high-density sinus floor and platform into the high-density ridge crest
(bicortical engagement)

64. Sinus lifting with crestal approach using DASK
(grinding up technique):
Fig . (A) Subantral bone which is inadequate (4–6 mm) in height for adequately long
implant placement. (B) Pilot drilling is done 2 mm short of the sinus floor.

65. Fig .(A and B) All osteotomy widening drills are used to the same depth (2 mm short
of sinus floor)

66. Fig. (A) After completing the osteotomy preparation for the implant 2 mm short of
sinus floor, a diamond-coated bur from DASK is used to grind the rest of the
subantral bone, to reach the Schneiderian membrane. (B–D) A sinus elevation probe
with its umbrella-shaped tip is used for lifting the sinus membrane to the desired
height.

67. Fig. (A and B) Elevated sinus space is grafted using HA Scaffold (70%) + β-TCP(30%)
– Osteon graft which also helps in further lifting the membrane.
Fig. After the elevated sinus floor has
successfully been grafted, the implant is
inserted.

68. Hydraulic sinus-lift technique:
by Chen in 2005
osteotomy is initiated with a sinus drill, and water
pressure is used to gently elevate the schneiderian
membrane from the sinus floor.

69. Intralift technique
Fig . (A) Ridge crest can be approached with flap technique or (B) with soft tissue
punch technique.

70. Fig. (A); If the subantral bone height is more than 3 mm and high in density, drilling should be
started with a 2 mm pilot drill of any implant system to reach 2 mm short of sinus floor if
subantral bone is less than 3 mm or low in density, drilling should be done with (B) TKW1 (1.35
mm) tip to reach 2 mm short of the sinus floor. (C) TKW2 (2.1 mm) tip is used to further widen
the osteotomy and grind the sinus floor to reach the membrane. These tips do not cut or damage
the soft tissue including the sinus membrane, unless if they are forcefully pushed up to tear the
membrane. (D) A TKW4 (2.8 mm) tip is then used to widen the crestal half of the osteotomy

71. Fig .(A) A resorbable collagen membrane or plug is inserted through the osteotomy to prevent
sinus membrane rupture during its hydraulic lift. (B) A TKW5 (2.8 mm) tip is inserted into the
prepared osteotomy limited to the crestal half, which then delivers a jet of sterile saline to
elevate the sinus membrane. A TKW5 (2.8 mm) tip is a noncutting tip that delivers sterile
irrigation spray right up to the end, used for Schneiderian membrane elevation by means of
microcavitation. The membrane elevation is achieved gradually, by using a series of
successively increasing rates of irrigation flow. (C and D) Once the sinus membrane has been
detached and elevated from the sinus floor, the osteotomy is further widened using TKW3 (2.35
mm) and TKW4 (2.8 mm) tips. This osteotomy is wide enough to insert a regular diameter
(3.5–4 mm) implant but if the insertion of a wider diameter implant is planned, the osteotomy
can be further widened at this stage, using the widening drills of the particular implant
system.

72. Fig. (A) The particulated graft is introduced through the osteotomy using graft carrier and (B) a
TKW5 tip is used to disperse the graft into the elevated sinus floor. (C) Then the graft can be
further added and (D) implant is inserted.

73.  Advantages of the intralift technique-
1. Minimally invasive technique
2. Safe and fast technique
3. Selective cut – cuts only bone without any injury to
soft tissues including sinus membrane
4. Haemostatic effect – minimum bleeding during the
surgery
5. Fast healing
6. Minimal failure risk.

74. Postoperative instructions to the patient
after the sinus-lift procedure
 Activities
1. Do not blow your nose for the next 4 weeks.
2. Be sure to sneeze with your mouth open.
3. Do not spit or drink with straws.
4. You should avoid flying in a pressurized aircraft or
scuba diving because it may increase sinus pressure.
5. You can take a decongestant to help reduce the pressure
in your sinuses.
6. You should not play musical instruments that require
you to blow or blow up balloons; avoid any other
activity that increases oral or nasal pressure.
7. Avoid lifting heavy objects.
8. Avoid smoking.

75. Complications after sinus graft
surgery and their management
 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

76. Membrane perforation/tearing
Fig. If the tear or perforation of the membrane occurs during its elevation, the continuation of
the sinus elevation procedure is modified. (A–D)The sinus membrane should be elevated off the
bony walls of the antrum all around the perforation and then a dry piece of collagen barrier
membrane should be placed to cover the perforation; the sinus is continued to be grafted as
planned and the implant is inserted.

77. Mucous retention cyst
Fig . Radiograph shows large mucous retention cyst in the sinus at the molar site. (B) The tooth is extracted
and (C) an osteotome is used to fracture the sinus floor. The mucous retention cyst is carefully punctured and
drained, using a sharp probe. The site is irrigated using the parenteral form of clindamycin. (D) Further, bone
substitute is deposited into the cavity and (E) the membrane is further lifted using the same osteotome and
the implant is inserted. (F) The peri-implant socket spaces are grafted and (G) site is covered with a
polytetrafluoroethylene (PTFE) cytoplast membrane, which is stabilized with sutures. (H) Postimplantation
radiograph shows elevated and grafted sinus and placed implant, without any visibility of the mucous
retention cyst. (I) The successfully osseointegrated implant is uncovered after 4 months for restoration.

78. Bleeding
PSA severed by vertical incision during lateral
window, if membrane elevated from medial wall of
sinus.
Haemostat agents
Extraosseous anastomoses are formed by the
infraorbital and posterior superior artery which is
located 23 mm from the dentate ridge crest but can
be located 10 mm from the resorbed ridge. Care
should be taken not to sever these anastomoses as
they bleed profusely

79. Antral septa
Antral septa mostly
found in the middle of
the sinus cavity (between
second premolar and
first molar region)
 Two separate lateral
windows should be
prepared to individually
access both the sinus
compartments
and their grafting.

80. Incision line opening
Periosteum should be released to achieve a tension-
free closure.
The soft tissue supported prosthesis should be
avoided during the primary healing of the soft tissue.
Swelling reduction-cryotherapy, hot fermentation.

81. Neural injury
If the infraorbital nerve gets severed during surgery,
the patient can feel paraesthesia in the infraorbital
region, in the lateral part of the nose and over the lip
on the same side.
This is a very uncommon complication and even if it
occurs, the sensations revert in a few weeks.

82. Acute maxillary sinusitis
 Mild postoperative infection-
 Symptoms:
1. Nasal discharge or nasal blockage
2. Pain and pressure in infraorbital area
3. Intraoral as well as extraoral swelling
4. Cough.
 Management:
1. Amoxicillin–clavulanic acid combination (tab. Augmentin,
625 mg one tab b.i.d. for 2 weeks)
2. Decongestant (Oxymetazoline, 0.05% for 3 days)
3. Nasal saline rinses.

83.  Moderate to severe postoperative infection-
 Symptom
1. Severe headache
2. High-grade fever
3. Swelling in periorbital region with ocular symptoms
like diplopia, proptosis
4. Altered mental status
5. Infraorbital hyperaesthesia.
 Management
1. Moxifloxacin, 400 mg one tablet b.i.d. for two weeks
2. Nasal saline rinses

84. SUMMARY
The maxillary sinus is a pyramid-shaped cavity with its
base adjacent to the nasal wall and apex pointing to the
zygoma. The size of the sinus is insignificant until the
eruption of permanent dentition. The average dimensions
of the adult sinus are 2.5–3.5 cm wide, 3.6–4.5 cm
tall, and 3.8–4.5 cm deep. It has an estimated volume
of approximately 12–15 cm. Anteriorly, it extends to the
canine and premolar area. The sinus floor usually has its
most inferior point near the first molar region.

85. Sinus elevation is a procedure that is very commonly being
performed. The techniques and approach should be performed only
after the proper hands-on training, to avoid postoperative
complications. the internal sinus elevation procedure should be
preferred for cases where a small height of sinus elevation is
required. The lateral approach should be preferred for the cases
where a large area and height of the sinus membrane needs to
be elevated.

86. For the lateral approach, if performed using
rotary bur, the large-diameter diamond bur should be
preferred over the carbide bur, to avoid the tearing of the
membrane. The oval window should be prepared for the
lateral approach, because the membrane can tear during
elevation at the corners of the rectangular osseous window.
Before start elevating the membrane, the osseous
window should be tapped using the back of the mouth
mirror handle, to fracture the small and thin bridges
between the osseous window and the surrounding bone.
The use of piezotome or DASK kit obviously offers several
advantages to perform safe and efficient sinus lifting.

87. The DASK kit or intralift obviously
offer several advantages for easy and safe lifting of
the sinus membrane. A careful evaluation of the lifted
sinus membrane is mandatory before starting the graft
of the sinus floor, as any tear in the membrane that has
already occurred, may result in the loss of the graft in
the sinus cavity and postoperative sinus infection.

88. REFERNCES
 B D CHAURASIA’S HUMAN ANATOMY
 ORABANS ORAL HISTOLOGY AND
EMBRYOLOGY
 JAMES K AVERY ESSENTIALS OF ORAL
HISTOLOGY,& EMBRYOLOGY
 CONTEMPORARY IMPLANT DENTISTRY CARL E.
MISCH
 CLINICAL IMPLANTOLOGY AJAY VIKRAM
SINGH