the use of osteointegrated implants has become a routine procedure for replacement of missing teeth . however , for better stability of implants , resorbed bone in edentulous regions often requires augmentation before an implant is inserted .
the posterior edentulous maxilla also presents special challenges in implant placement compared with other areas of the mouth due to progressive resorption that results in less available bone .
this poor quality and quantity of available bone challenge the essential condition for successful implant placement .
tatum was the first to report the penetration of the maxillary sinus with a modified caldwell - luc technique . in the posterior maxilla , using an unfinished fenestration osteotomy in the maxilla 's external face , a space is created between the residual maxillary ridge and the schneiderian membrane , commonly known as the  sinus lift procedure  .
adequate bone formation in this space can be achieved with a variety of graft materials when a reasonable healing period ( 5 - 6 months ) is allowed .
autologous bone from the iliac crest has been used most commonly and successfully for reconstruction of a variety of osseous defects . however , to overcome its disadvantages and to reduce morbidity at the donor site , allogeneic , xenogenous , alloplastic , or composite materials were introduced .
. however , autologous tissue - engineered osteoblasts offer important advantages compared with conventional autogenous bone grafts because the donor site morbidity is minimal and are performed as an outpatient procedure with local anesthesia .
we present a case where tissue - engineered autologous osteoblasts were used in combination with demineralized freeze - dried bone ( dfdb ) for bilateral sinus lift procedure .
a 52-year - old female reported to the department of oral and maxillofacial surgery for the placement of implants in order to receive the implant - supported prosthesis in her bilateral edentulous posterior maxillary regions .
the patient had been given other prosthetic options but decided upon implant - supported prosthesis .
the medical history revealed that the patient was type ii diabetic , hypertensive , asthmatic , anemic , and osteoporotic .
subsequent radiographic evaluation ( orthopantomography [ opg ] and cone - beam computed tomography ) revealed sinus pneumatization on both the sides [ figures 1 and 2 ] .
preoperative orthopantomography showing the deficient height in the posterior maxilla cone - beam computed tomography showing sinus pneumatization on both the sides the treatment plan included sinus lift procedure using ossron ( autologous tissue - engineered osteoblasts ) and dfdb graft , followed by , insertion of dental implants and the subsequent prosthetic phase .
when her medical conditions were found to be well under control , she was taken up for the harvest of bone marrow and bilateral sinus lift procedure .
six weeks before , the sinus lift procedure , the marrow cells were harvested from posterior superior iliac crest with bone marrow aspiration technique . the surgical site , posterior iliac crest was prepared with standard surgical protocol .
needle - 11 gz  10 cm ( care fusion ) was inserted and about 10 ml bone marrow was harvested and collected in two bottles with dulbeccos modified eagles 's medium .
the specimen was transported to rms regrow laboratory , maintaining the temperature between 2c and 8c .
after 6 weeks , when the osteoblasts were ready to be implanted , the patient was taken under sedation and local anesthesia using lignocaine 2% with adrenaline 1:80,000 for bilateral infra - orbital , posterior superior alveolar and greater palatine nerve blocks .
prophylactic antibiotics were administered before the procedure . the patient was scrubbed and draped as per standard surgical protocol .
a trapezoidal muco - periosteal flap was reflected from the distal aspect of 13 to 18 region using a crestal incision and anterior and posterior releasing incisions .
a 1.5 cm  1 cm bony window was created in the antero - lateral wall of the maxilla , approximately 3 mm superior to the crest .
the membrane was elevated inferiorly , anteriorly , and posteriorly together with the bony window [ figure 3 ] until the desired elevation was reached keeping it well below the level of the ostium , as guided by the measurements on the computed tomography .
the space thus created between the bony floor of the sinus and the membrane was filled with ossron [ figure 4 ] and dfdb ( allograft ) , making a putty [ figure 5 ] .
hemostasis was achieved and the flap was repositioned and sutured with 4 - 0 vicryl .
there was slight anatomical difference between the two sides , with the left sinus being narrower mediolaterally than the right .
the patient was discharged after 2 h. she was prescribed antibiotics and analgesics for 5 days .
elevation of the sinus membrane placement of demineralized freeze - dried bone ( allograft ) three months postoperative orthopantomography showing adequate bone height
six weeks before , the sinus lift procedure , the marrow cells were harvested from posterior superior iliac crest with bone marrow aspiration technique . the surgical site , posterior iliac crest was prepared with standard surgical protocol .
needle - 11 gz  10 cm ( care fusion ) was inserted and about 10 ml bone marrow was harvested and collected in two bottles with dulbeccos modified eagles 's medium .
the specimen was transported to rms regrow laboratory , maintaining the temperature between 2c and 8c .
after 6 weeks , when the osteoblasts were ready to be implanted , the patient was taken under sedation and local anesthesia using lignocaine 2% with adrenaline 1:80,000 for bilateral infra - orbital , posterior superior alveolar and greater palatine nerve blocks .
prophylactic antibiotics were administered before the procedure . the patient was scrubbed and draped as per standard surgical protocol .
a trapezoidal muco - periosteal flap was reflected from the distal aspect of 13 to 18 region using a crestal incision and anterior and posterior releasing incisions .
a 1.5 cm  1 cm bony window was created in the antero - lateral wall of the maxilla , approximately 3 mm superior to the crest .
the membrane was elevated inferiorly , anteriorly , and posteriorly together with the bony window [ figure 3 ] until the desired elevation was reached keeping it well below the level of the ostium , as guided by the measurements on the computed tomography .
the space thus created between the bony floor of the sinus and the membrane was filled with ossron [ figure 4 ] and dfdb ( allograft ) , making a putty [ figure 5 ] .
hemostasis was achieved and the flap was repositioned and sutured with 4 - 0 vicryl .
there was slight anatomical difference between the two sides , with the left sinus being narrower mediolaterally than the right .
the patient was discharged after 2 h. she was prescribed antibiotics and analgesics for 5 days .
elevation of the sinus membrane placement of demineralized freeze - dried bone ( allograft ) three months postoperative orthopantomography showing adequate bone height
sinus lift procedure has become a predictable and acceptable technique for bone augmentation in the posterior maxilla . since its first description by tatum in 1976 ,
the more notable ones are by boyne and james in 1980 , kent and block 1989 .
subsequently , jensen et al . described a two - stage procedure for sinus lift followed by implant placement at a later date .
described a single stage procedure of immediate implants placement at the time of sinus lift procedure . with the procedure and technique
now almost been a routine , the current trend is toward making bone grafting and bone formation more predictable .
use of autologous bone for grafting has been advocated by many . though autologous bone is the gold standard for sinus grafting , it has the limitations of requiring donor site and the need for hospital care , especially if iliac crest bone harvesting is involved .
apart from potential problems such as pain and infection at the donor site , intraoral bone grafts have a limited volume .
tissue - engineering procedures for bony augmentations of the maxilla offer significant advantages compared with conventional grafts , as there is minimal or no donor site morbidity .
ideally , these procedures are used under outpatient conditions under local anesthesia , using exclusively autologous material with bone forming capacity .
the ongoing development of tissue - engineered materials is aiming at a significant reduction in donor site morbidity and providing materials with better mechanical properties than those currently used bone marrow stromal cells ( bmsc s ) have been regarded as multi potent cells residing in bone marrow . under adequate culture conditions ,
bmsc 's can differentiate into various lineages of mesenchymal tissues , including bone , cartilage , fat , tendon , muscle , and marrow stroma .
first described the use of periosteum derived tissue - engineered bone for sinus grafting in two patients .
a year later , they reported their study for 27 patients and their results suggest that periosteum - derived osteoblasts on a suitable matrix can form lamellar bone within 3 months after transplantation and provide a reliable basis for simultaneous or secondary insertion of dental implants .
, we have used autologous osteoblasts obtained and cultured from bone marrow aspirate of posterior iliac crest . as per our knowledge
furthermore , the sole use of alloplast or allografts would not have been a good option in a diabetic patient due to the compromised microvasculature .
we have also combined the same with dfdb so as to achieve greater volume and take advantage of the excellent osteoinductive characteristics of autologous osteoblasts .
the postoperative radiograph shows adequate height of the bilateral posterior maxillary edentulous alveolar ridge , with no postoperative sequelae .
we believe tissue engineering makes it possible to fill larger volumes of the sinus cavity and provides predictable bone formation as compared to alloplasts and allografts . tissue engineering also reduces donor site morbidity and makes the procedure more acceptable to the patient .
this study can be regarded as a pilot study ; further such studies on a larger scale can be carried out especially in such medically compromised cases where large volume autologous bone is not possible to harvest .
 the pneumatization of the maxillary sinus often results in a lack of sufficient alveolar bone for implant placement . in the last decades 
 , maxillary sinus lift has become a very popular procedure with predictable results . 
 sinus floor augmentation procedures are generally carried out using autologous bone grafts , bone substitutes , or composites of bone and bone substitutes . 
 however , the inherent limitations associated with each of these , have directed the attention of investigators to new technologies like bone tissue engineering . 
 bone marrow stromal cells have been regarded as multi - potent cells residing in bone marrow . 
 these cells can be harvested from a person , multiplied outside his body using bioengineering principles and technologies and later introduced into a tissue defect . 
 we present a case where tissue - engineered autologous osteoblasts were used along with demineralized freeze - dried bone for sinus floor augmentation . 
Introduction
Case Report
Harvest of bone marrow
Sinus lift
Discussion
Conclusion