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ORIGINAL ARTICLE |
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Year : 2012 | Volume
: 2
| Issue : 1 | Page : 26-31 |
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Evaluation of increase in bone height following maxillary sinus augmentation using direct and indirect technique
Diana Daniel1, S Girish Rao2
1 Sr Lecturer, Department of Oral and Maxillofacial Surgery, Bangalore Institute of Dental Sciences, Bangalore, India 2 Professor and Head D. A. Pandu Memorial R. V. Dental College and Hospital, Bangalore, India
Date of Web Publication | 24-May-2012 |
Correspondence Address: Diana Daniel 201/A, Seven Hills Excellency, No. 33, 2nd Cross, SBM Colony, Mathikere, Bangalore - 560 054 India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0974-6781.96563
Abstract | | |
Aims: Prospective study to evaluate the increase in bone height following maxillary sinus augmentation using direct and indirect techniques. Settings and Design: The sample was drawn from the patients reporting to the Department of Oral and Maxillofacial Surgery, D. A. Pandu Memorial R. V. Dental College and Hospital, Bangalore, seeking implant options for oral rehabilitation Materials and Methods: Ten patients with unfavorable post-extraction resorptive patterns and increased pneumatization of the maxillary sinus were included for the purpose of study. In all, a total of 22 implants have been placed in maxillary bone with augmented maxillary sinuses. Statistical Analysis Used: Wilcoxon signed ranks test. Results: In the direct technique group, the average increase in median bone height from pre-operative time interval to post-operative time interval was noted to be 9.5 mm and this was statistically significant (P<0.01). Similarly, the average increase in median bone height from preoperative time interval to postoperative time interval in the indirect technique group was noted to be 5.5 mm and this was statistically significant (P<0.01). Conclusions: By the findings of this study, we can safely conclude that the average increase in bone height in the direct technique group was higher (9.5 mm) than the average increase in bone height in the indirect technique group (5.5 mm). Keywords: Direct sinus lift technique, implant, indirect sinus lift technique
How to cite this article: Daniel D, Rao S G. Evaluation of increase in bone height following maxillary sinus augmentation using direct and indirect technique. J Dent Implant 2012;2:26-31 |
How to cite this URL: Daniel D, Rao S G. Evaluation of increase in bone height following maxillary sinus augmentation using direct and indirect technique. J Dent Implant [serial online] 2012 [cited 2023 May 31];2:26-31. Available from: https://www.jdionline.org/text.asp?2012/2/1/26/96563 |
Introduction | |  |
Edentulism is a condition that keeps many people from "feeling their best". It not only affects the self confidence, but also has a dramatic impact on the quality of life. Dental implants currently are the closest thing technology has to offer in lieu of a natural tooth. Implant success in posterior maxilla is frequently challenged by unfavorable post-extraction resorptive patterns, pneumatization of the maxillary sinus, and the often poor quality of the remaining alveolar bone. Hence, sinus floor elevation has become an important procedure in peri-implant grafting. [1] Various maxillary sinus floor augmentation techniques have been proposed for managing severe bone loss in the posterior maxilla. [2],[3] There have been reports of successful bone formation in sinus floor elevation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials, although these reports do not address the height of new bone formation possible using this procedure. [4],[5] The present prospective study was undertaken to evaluate the gain in height of new bone formation in the maxillary sinus following direct and indirect sinus lift technique and insertion of titanium implants with/without additional grafting material.
Materials and Methods | |  |
The study involved placing 22 self-threaded titanium implants in 10 (female = 5; male = 5) patients by direct (n=11) and indirect (n=11) technique. The sample was drawn from the patients reporting to the Department of Oral and Maxillofacial Surgery, seeking implant options for oral rehabilitation [Table 1]. Patients presenting with edentulous, atrophic maxillary arch either due to physiological aging, trauma, or periodontal conditions and patients presenting with one or more missing teeth in the posterior maxillary arch, either unilaterally or bilaterally with pre-operative bone height of <7 mm in the posterior maxilla was included in the study. Patients with systemic illness/systemic drugs that would affect postoperative healing; patients with poor oral hygiene, chronic smokers, psychiatric illness, pre- existing sinus problem or unwilling for the follow-up and pre-operative bone height > 7 mm in the posterior maxilla was excluded from the study.
Radiographic evaluation
Panoramic radiographs were used for screening examinations and treatment planning of the patients to get a broad perspective of the maxillary sinus, and nasal floor; and were used to assess the depth of the bone available. Since the panoramic films generally have a magnification factor of about 25%, this was anticipated and eliminated during the patient work-up to gain better appreciation of the actual position of vital structures and the size of implant to be selected. The OPGs were standardized by using known diameter stainless steel shots incorporated in a vacuum-formed stent in the proposed implant site worn by the patient at the time of radiography. The distortion was calculated by comparing the actual diameter of the steel shots with the radiographic diameter as
Distortion = Normal diameter of the steel shot × 100
Radiographic diameter
Bone mapping was done for assessment of transverse thickness of bone. The procedure involved anesthetizing the proposed area of the patient and marking the depth of the soft tissue over the alveolar bone using a sterile file at various levels and then marking the recorded depth of the bone over a sectioned cast of the patient.
Surgical technique
All patients were operated under local anesthesia. Standard conditions of asepsis and sterility were adhered to during the implant placement procedures. Implants were placed either simultaneously following the sinus elevation procedure (Indirect) or following a healing period of six months (Direct).
Direct surgical technique
The surgical incision was made on the crest, with vertical releasing curvilinear incisions flaring into the vestibule. Full-thickness subperiosteal labial and palatal flaps were reflected to expose the crest and to provide visualization of the antero-lateral wall of maxillary sinus. The incision ensured adequate buccal and palatal attached tissue on either side. The infra-orbital nerve was identified and protected. The dimension of the osteotomy was determined based on the clinical and radiographic examinations. The buccal bone window was created on the antero-lateral wall of the maxillary sinus behind the canine fossa using a postage stamp method [Figure 1]. The bony wall was gently elevated with sinus membrane elevators without damaging the schneiderian membrane. The graft material was then placed and packed. If the height of the bone was greater than 5 mm the implant was placed in the same sitting. If the height of the bone was less than 5 mm, the graft was allowed to consolidate over a period of next 6 months. Subsequently, under local anesthesia the alveolar bone to receive the implant was exposed and a flat implant bed was prepared using a rosehead bur wherever it was found necessary. A surgical stent having guide channel was used to place the implant in the correct position and a small round bur or spiral drill was used to mark the implant site. The stent was then removed and the site was checked for appropriate facio-lingual and mesio-distal positioning. Any obvious crestal defect required slight modification of the position. A pilot drill usually 2 mm in diameter was then drilled in the marked implant site to establish the depth and axis of implant recipient site. The implant was placed with its axis parallel to the occlusal forces, with the emergence of the implant angling to meet the functional cusp of the opposing teeth. Paralleling pins were used to check the parallelism of the drill holes to the adjacent teeth as well as adjacent implant recipient sites, in case multiple implants were being placed. The drills were used in a reduction gear hand piece along with a physio-dispenser enabling internal as well as external irrigation to prevent excessive heat generation. The drill was used at the speed of 800 to 1000 rpm with copious irrigation. The paralleling pins were used at each stage of surgery to ensure that the axis of the recipient site is not changed. Following the pilot drill, drills with gradually increasing diameters were used to enlarge the implant recipient site till the desired diameter corresponding to the implant diameter was reached. Implants were then placed into the prepared site using a torque wrench. 3-0 Vicryl sutures were used to close the surgical wound. The patients were monitored on a periodic basis both clinically and radiologically [Figure 1]a-d. | Figure 1a: Indirect sinus lift technique using angulated sinus osteotome Figure 1b: Implant in situ and bone graft imamate post-operative Figure 1c: Six months' post-operative orthopantomograph showing the implant Figure 1d: Nine months' post-operative orthopantomograph showing implant with prosthesis
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Outline of the osteotomy cut inward and upward rotation graft placed of the lateral sinus wall in trap door technique.
Indirect surgical technique
The alveolar cortical bone to receive the implant was exposed under profound anesthesia and perforated using a rounded drill. A pilot drill usually 2 mm in diameter was then drilled in the marked implant site to establish the axis of implant recipient site. Following the pilot drill, drills with gradually increasing diameters were used to enlarge the implant recipient site till the desired diameter corresponding to the implant diameter was reached. The height was maintained 2 mm short of sinus floor. The indirect sinus lift was carried out by insertion of the correct-caliber osteotome and working up through the successively greater instrument diameters, until the sinus floor was fractured and elevated up. The sinus floor was then fractured and separated from the sinus membrane avoiding damage to the membrane using a surgical mallet. The graft material was inserted within the socket, if required. The material was displaced apically with the help of larger-diameter instruments, thereby lifting the membrane and condensing the graft material between the latter and the sinus floor. The implant was then placed immediately in the prepared site. 3-0 Vicryl sutures were placed to close the surgical wound. The patients were monitored on a periodic basis both clinically and radiologically [Figure 2]a-f. | Figure 2a: Pre-operative orthopantomograph Figure 2b: Elevation of the sinus membrane using the balloon technique Figure 2c: Creation of a bony window in the mandibular symphysis region for graft harvest Figure 2d: Clinical picture showing the insertion of the graft material Figure 2e: Immediate post-operative Figure 2f: One-year post-operative orthopantomograph showing the implant with prosthesis
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Results | |  |
In the present study we have made an attempt to evaluate the increase in bone height following maxillary sinus augmentation by Direct (n=11) and Indirect (n=11) technique. The study involved placing 22 self-threaded titanium implants in 10 (Female = 5; Male = 5) patients. All the patients included in the study ranged between 14 and 65 years of age. All the patients had undergone atraumatic extraction of teeth in the upper posterior teeth region. The average period of edentulousness was 2.2 ± 1.40 years. The implants were placed under local anesthesia with antibiotic cover and sterile condition in the predetermined site. The average implant diameter used in all cases was 4.50 ± 0.46 mm. Bone regeneration was spontaneous in certain cases (n=09) and was accelerated by the placement of a combination of autogenous and alloplastic graft materials in the remaining few cases (n=13). During the follow-ups, each implant was checked for clinical and radiological signs of implant failure such as infection of peri-implant tissue, implant mobility and presence of radiolucent line around the implant when seen on the radiograph. All the implants were exposed between sixth to eight months and were checked for clinical mobility once the healing caps were placed. The gingival healing caps were left in place for a period of two to three weeks to give time for the gingival collar to form around the implant. Once the gingival healing was complete the healing caps were replaced with abutments for the respective implants and then the patients were referred to the Department of Prosthodontics for Dental Rehabilitation. At the time of exposure and further follow-ups there was no evidence of peri-implant infections, as well there was no clinical mobility of the implants and follow-up radiographs showed no peri-implant radiolucency indicating excellent osseointegration. We used Wilcoxon Signed Ranks test to evaluate the increase in bone height in Direct and Indirect technique group at pre-operative and post-operative time intervals
In the direct technique group, the average increase in median bone height from pre-operative time interval to post-operative time interval was noted to be 9.5 mm and this was statistically significant (P < 0.01). Similarly, the average increase in median bone height from pre-operative time interval to post-operative time interval in the indirect technique group was noted to be 5.5 mm and this was statistically significant (P < 0.01).
Discussion | |  |
During the past decade, implants have become one of the most exciting and rapidly developing topics in dental practice as they provide a proper treatment alternative to conservative prosthodontics. In the posterior maxilla anatomical limitations (such as deficiency of maxillary alveolar bone and increased pneumatization of the maxillary sinuses) constitute a challenging problem. Because there is little available bone volume in this region, sinus floor elevation is a pre-requisite to implant placement. In the present study the sinus augmentation is done either by direct technique or indirect technique as a single step procedure or a two-step procedure. Despite two surgical operations being performed to place a few implants (n=11), no significant complications were reported. Graziani F compared implant survival following sinus floor augmentation procedures with implants placed in posterior maxillary bone and demonstrated survival between 75% and 100% both for non-augmented and augmented areas. [6] Milan Jurisic, in his study on maxillary sinus floor augmentation compared osteotome with lateral window technique with immediate and delayed implant placements on 61 patients. [7] The implant survival rates were assessed clinically and radiographically and 100% success was achieved using either osteotome or lateral approaches to augment the maxillary sinus floor. This finding was in concurrence with the findings in the present study. Nicola et al. compared the crestal and lateral approaches and the gain in bone height was comparable for the one-step (median = 10 mm) and two-step (median = 12.7 mm) procedures. [8] In the present study the median gain in bone height (12 mm) was almost same for direct technique and indirect technique (11.5 mm). In the present study the sinus augmentation is done either by direct technique or indirect technique as a single step procedure or a two step procedure. Despite two surgical operations being performed to place a few implants (n=11), no significant complications were reported. Graziani F compared implant survival following sinus floor augmentation procedures with implants placed in posterior maxillary bone and demonstrated survival between 75% and 100% both for non-augmented and augmented areas. [6] Milan Jurisic in his study on maxillary sinus floor augmentation compared osteotome with lateral window technique with immediate and delayed implant placements on 61 patients. [7] The implant survival rates were assessed clinically and radiographically and 100% success was achieved using either osteotome or lateral approaches to augment the maxillary sinus floor. This finding was in concurrence with the findings in the present study. Nicola et al. compared the crestal and lateral approaches and the gain in bone height was comparable for the one-step (median = 10 mm) and two-step (median = 12.7 mm) procedures. [8] In the present study the average increase in bone height in the direct technique group was higher (9.5 mm) than the average increase in bone height in the indirect technique group (5.5 mm).
Conclusion | |  |
In our study 22 implants were placed in augmented sinus bone. All the patients were followed up for a period of 6 months to one year. There was no undesirable event as far as the ease of placement is concerned and the healing period after the surgery was also uneventful. The follow-up period after implant placement was uneventful and none of the implants were rejected or infected; the implants were then exposed during the second stage and gingival healing caps were placed and left in situ for a period of 15 days to one month. Clinical mobility was checked immediately after healing caps were placed and was reassessed in each of the follow-up appointments, and even during the prosthetic phase. None of the implants showed any clinical mobility. Radiographs were also taken periodically to assess the presence of any peri-implant radiolucency; none of the 22 implants showed any radiolucency showing successful osseointegration. The findings are also in concurrence with a study done by Milan Jurisic and Aleksa Markovic et al.,[7] which compared maxillary sinus floor augmentation with osteotome v/s lateral window technique with immediate and delayed implant placements and demonstrated a success rate of 100%. Seung-Mi Jeong et al. [9] in his study placed 10 implants in residual bone height of 4-6 mm and gained mean endosinus gain of 3.5 ± 0.6 mm. In our study, we noticed that in the direct technique group the average increase in median bone height from pre-operative time interval to postoperative time interval was 9.5 mm and this was statistically significant (P<0.01). Similarly, the average increase in median bone height from pre-operative time interval to post-operative time interval in the indirect technique group was noted to be 5.5 mm and this was statistically significant (P<0.01) [Table 2]. By the findings of this study, we can safely conclude that the average increase in bone height in the direct technique group was higher (9.5 mm) than the average increase in bone height in the indirect technique group (5.5 mm).
References | |  |
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[Figure 1], [Figure 2]
[Table 1], [Table 2]
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