Maxillary Posterior Area Research Articles

SINUS FLOOR AUGMENTATION WITH BONE BLOCK GRAFTING AND SIMULTANEOUS IMPLANT PLACEMENT

SUMMARY Placement of dental implants in the posterior maxillary edentulous areas is often compromised by the limited volume of bone due to the anatomy of the maxillary sinuses. In such cases, the technique of Sinus Lift is indicated to provide a sufficient volume of hard tissue in order to achieve primary stability at implant placement. Simultaneous augmentation of the sinus floor and implant placement is severely limited by the amount of residual bone of the floor of the sinus. A clinical case of minimal residual bone at the bottom of the sinus is demonstrated. A sinus floor augmentation with bone block harvested from the mandibular symphysis is performed. The bone block is placed in the sinus after membrane elevation and fixed with a screw to the sinus floor. After fixation of the bone block in the sinus implant (10/4.1 mm TSV (Zimmer)) is placed in reconstructed bone with good primary stability. Healing occurs without complications and the third month X-ray showed normal density of bone around the implant. The technique is very sensitive to surgeon’s skills.

Outfracture Osteotomy Sinus Graft에 대한 임상적 연구

Purpose: The purpose of this study was to evaluate the feasibility of the outfracture osteotomy sinus graft technique with the evaluation of 8.5 year survival rate of the implants placed in the atrophic edentulous posterior maxillary area. Methods: One hundred and seventy-six cases of 145 patients who visited our center from August 2004 to February 2013 and were diagnosed as atrophic edentulous maxillary alveolar ridge, were selected and underwent sinus graft with outfracture osteotomy sinus graft technique. Feasibility of the outfracture osteotomy sinus graft technique was investigated with clinical and radiographic evaluation to assess the survival rate of the total dental implants in augmentation sinus surgery. Total fixture number available in follow-up period was 320, in which the lost 15 patients were excluded out of 160 patients. Results: Eight point five year cumulative survival rate was 95.6% with 14 failures of total 320 fixtures. The average follow-up period was 28 months 16 days with the minimum and maximum follow-up periods of 4 months 5 days and 94 months 10 days, respectively. Conclusion: Traditional infracture technique is a popular method for an augmentation sinus surgery. The authors modified this classical method by outfracturing and readapting the bony window after sinus graft, with excellent treatment results evidenced by high survival rate, which proves the feasibility of the newly-designed outfracture osteotomy sinus graft technique.

Sinus Bone Grafting Technique Using Special Reamers and Microelevators

When residual bone height is insufficient in the maxillary posterior area, the maxillary sinus elevation and implant placement with lateral approach are oftentimes used. However, the risk of sinus membrane perforation, or tearing, is high for this procedure. This article introduces a technique that uses a special reamer and a microelevator to minimize sinus membrane injury.

An analysis of failure of 5-year loaded tapered implants with SLA surface

The purpose of this study was to analyze the risk factors for 5-year loaded tapered implants with SLA surface. From June 2003 to February 2005, 65 patients (a total of 139 Implantium® (Dentium, Suwon, Korea) implants) were enrolled and cumulative survival was calculated based on Kaplan–Meier method. To confirm prognosis factors, Cox proportional hazard model was established. Among the 139 implants, 6 implants failed and the 5-year cumulative survival rate was 95.41%. Failed implants were 3 for osseointegration failure, 1 for malposition, and 2 for peri-implantitis and progressive bone loss respectively. There were no meaningful differences in the cumulative survival rates between maxilla and mandible, maxillary posterior area and other regions, and maxillary posterior area with and without sinus bone graft (p>0.05). Irrespective of graft location, delayed loaded cases due to improper primary stability from simultaneous bone graft increased the failure rate.

Prospective study of tapered resorbable blasting media surface implant stability in the maxillary posterior area

The purpose of this study was to evaluate the stability of tapered resorbable blasting media surface implants in the posterior maxilla. From September 2008 through January 2010, 20 patients (9 men, 11 women) who were treated with tapered GS III implants at Seoul National University Bundang Hospital were identified. Thirty-eight implants (14 premolar and 24 mol/L) were placed in maxillary posterior areas. The patients' mean age was 52.1 years, and the mean follow-up period was 12.6 months after final prosthesis delivery. The implant length was 11.8 ± 1.4 mm with a diameter of 4.6 ± 0.5 mm. The 1-year survival rate was 97.4%, and the success rate was 94.7%. The implant stability quotient value at implant placement was 63.6 and 74.4 at the second surgery, which indicated a significant difference. There was no significant difference in crestal bone loss according to implant diameter or length or sinus bone graft. This study showed the favorable clinical outcome of tapered implants that were placed in the maxillary posterior area.

Clinical and radiographic changes at implants supporting single‐unit crowns (SCs) and fixed dental prostheses (FDPs) with one cantilever extension. A retrospective study

To evaluate the clinical and radiographic changes at implants in posterior maxillary and mandibular areas supporting single-unit crowns (SCs) and fixed dental prostheses (FDPs) with one mesial or distal cantilever extension after an observation period of at least 3 years. Seventeen subjects with 19 implant-supported SCs and 21 subjects with 21 implant-supported FDPs fulfilled the inclusion criteria. All FDPs were supported by two implants and had a span of 3-4 units. All reconstructions were incorporated in the posterior maxilla or mandible. The mesial and distal radiographic marginal bone loss from baseline (i.e. delivery of the reconstruction) to the follow-up examination was averaged and compared between SCs supporting one cantilever extension with that of implants supporting FDPs adjacent to or distant from the cantilever extension. Changes in mean pocket probing depth (PPD) were calculated and compared between the three groups. The mean observation period was 78.2 ± 34.5 months for SCs supported by one implant and 67.8 ± 29.8 months for FDPs supported by two implants. No implant loss occurred, yielding a 100% survival rate. At baseline, the mean radiographic bone levels ± SD were 2.6 ± 0.3 mm for implants supporting SCs, 2.6 ± 0.3 mm for implants of FDPs adjacent to the cantilever extension, and 2.4 ± 0.5 mm for implants of FDPs distant from the cantilever extension. At follow-up, the corresponding mean bone levels ± SD were 2.7 ± 0.4, 2.7 ± 0.5, and 2.8 ± 0.5 mm, respectively. No statistically significant differences (P > 0.05) were observed comparing the mean marginal bone loss between the three groups. Moreover, mean changes in PPD between baseline and follow-up were not statistically significantly different (P > 0.05) between the three groups. The presence of one mesial or distal cantilever extension in the posterior maxilla or mandible does not jeopardize the marginal bone levels of implants supporting SCs or short-span FDPs after a mean observation period of at least 5 years.

Hydrodynamic ultrasonic maxillary sinus lift: Review of a new technique and presentation of a clinical case

Objectives: Placing implants in the posterior maxillary area has the drawback of working with scarce, poor quality bone in a significant percentage of cases. Numerous advanced surgical techniques have been developed to overcome the difficulties associated with these limitations. Subsequent to reports on the elevation of the maxillary sinus through the lateral approach, there were reports on the use of the crestal approach, which is less aggressive but requires a minimal amount of bone. Furthermore, it is more sensitive to operator technique, as the integrity of the sinus membrane is checked indirectly. The aim of this paper is to review the technical literature on minimally invasive sinus lift and compare the advantages of different techniques with Intralift™, a new technique. Study Design: The present study is a review of techniques used to perform minimally invasive sinus lift published in Cochrane, Embase and Medline over the past ten years and the description of the crestal sinus lift technique based on minimally invasive piezosurgery, with the example of a case report. Results: Only eight articles were found on minimally invasive techniques for sinus lift. The main advantage of this new technique, Intralift, is that it does not require a minimum amount of crestal bone (indeed, the smaller the width of the crestal bone, the better this technique is performed). The possibility of damage to the sinus membrane is minimised by using ultrasound based hydrodynamic pressure to lift it, while applying a very non-aggressive crestal approach. Conclusions: We believe that this technique is an advance in the search for less traumatic and aggressive techniques, which is the hallmark of current surgery. Key words: Sinus lift, surgical technique, minimally invasive surgery, ultrasound surgery.

Reamer‐mediated transalveolar sinus floor elevation without osteotome and simultaneous implant placement in the maxillary molar area: clinical outcomes of 391 implants in 380 patients

Minimally invasive sinus elevation and augmentation using a transalveolar approach can reduce perioperative complications and patient discomfort. A specially designed reamer accomplishes this without the use of an osteotome or a mallet. The objective of this study is to present this technique with relevant clinical cases and patient outcomes. Series of reamers with one cutting and one reaming edge were used to prepare an osteotomy site for posterior maxillary areas. A total of 391 osteotomies were prepared with the reamer in 380 patients, and 373 implants were placed simultaneously. In addition to the procedure's success parameters, levels of intraoperative patient comfort were monitored using a visual analogue scale. The mean height of the residual alveolar process was 5.8 (0.9) mm, whereas mean elevation of the sinus floor was 6.2 (0.4) mm. Eighteen (4.6%) Schneiderian membrane perforations occurred, and the 2-year survival rate was 95.4%. The success rate was 92.7% in sites with thin sinus floors (< 4 mm) and 96.4% in sites with greater bone height (> 4 mm). None of the patients experienced any discomfort during the procedure. Within the limits of the present study, it can be concluded that reamer-mediated transalveolar sinus floor elevation is a reliable method for implant placement in the posterior maxilla, even at sites with ≤ 4 mm of residual alveolar bone height. This reamer-mediated procedure is less invasive than traditional osteotomy and can minimize patient discomfort during sinus floor elevation.

Maxillary anterior and mandibular posterior residual ridge resorption in patients wearing a mandibular implant-retained overdenture

The mandibular implant-retained overdenture could improve masticatory function compared to the conventional complete denture. However, increased forces exerted by the overdenture could increase residual ridge resorption of the maxillary anterior and mandibular posterior areas. The aim of this study was to compare the effect of the mandibular implant-retained overdenture using two or four dental implants, or the conventional complete denture on resorption of the residual ridge of the maxillary anterior and mandibular posterior areas over a period of 10 years. In total, 120 patients, 30 patients treated with an overdenture on two implants (two-implant group), 30 patients with an overdenture on four implants (four-implant group) and 60 patients treated with a conventional full denture (conventional group), participated in this study. On panoramic radiographs, made before and 10 years after treatment, proportional area measurements were applied to determine changes in bone height. After 10 years, a statistically significant amount of bone resorption had occurred in the anterior maxilla in the two-implant group and in the four-implant group. A significant amount of bone resorption had occurred in the posterior mandible in all three groups. There were no statistically significant differences between the groups in both areas. Patients presented large individual differences. It is concluded that patients rehabilitated with implant-retained mandibular overdentures are not subjected to more residual ridge resorption in the anterior maxilla when compared to patients wearing a conventional full denture. Regarding the mandibular posterior residual ridge, resorption was irrespective of wearing an implant-retained mandibular overdenture or a conventional mandibular denture.

A cone beam computer tomographic study of the cortical bone thickness in different class II facial patterns

PurposeThe purpose of this study was to determine the difference of cortical bone thickness in different Frankfort to Mandibular plane angle (FMA) and anatomical areas by cone beam CT. Materials and methodsTwenty skeletal class II adult females were included, and divided into three groups by the FMA: the high FMA group, average FMA group, and low FMA group. Their cone beam computer tomography data were used for measurements and statistics. The cortical bone thickness was measured in five anatomical areas: (a) the labial alveolar bone located 2.0mm below the root apex of the mandibular central incisors, (b) the buccal shelf alveolar bone located between the mandibular first and second molars, (c) the labial alveolar bone located 2.0mm above the root apex of the maxillary central incisors, (d) the buccal alveolar bone located 3.0mm above the alveolar crest between the maxillary second premolar and the first molar, and (e) the infrazygomatic crest. ResultsThe right and left measurements of cortical bone thickness in five anatomical sites were not significantly different. This study also compared the cortical bone thickness with the patient's age, but no significant differences were observed.The results revealed no significant difference in cortical bone thickness with respect to FMA. The cortical bone thickness in the posterior area was higher than that in the anterior area. Both the anterior area and the posterior area of the mandible were thicker than those of the maxilla, but the bone thickness in the maxillary posterior area and infrazygomatic crest showed no significant difference. ConclusionAlthough the cortical bone thickness did not show a significant difference, such difference was present in different areas. Lower posterior>infrazygomatic crest, upper posterior>lower anterior>upper anterior. The upper posterior area and the infrazygomatic crest area showed no significant difference.

Cervical Enamel Projections in Unusual Locations: A Case Report and Mini‐Review

Periodontitis is primarily a bacteria-induced disease that can be modified by tooth-related local factors. Cervical enamel projections (CEPs) are a common tooth anomaly that can act as contributing factors in the development of periodontitis. They are most commonly found at the buccal surfaces of mandibular molars. A 57-year-old female was referred to our clinic for treatment of chronic periodontitis. A clinical examination revealed moderate attachment loss that was localized to the palatal side of the maxillary second molars. The rest of the dentition was less affected, with a diagnosis of generalized slight chronic periodontitis. An initial non-surgical periodontal treatment was provided followed by apically positioned flap surgery in the maxillary right and left posterior areas. At the time of surgery, CEPs were found where the periodontium was most affected. Because surgical intervention exposed the CEPs, they were not removed. After the active therapy, which resulted in inflammation resolution and maintainable probing depths, the patient was placed on a 3-month recall for periodontal maintenance. CEPs were found in an unusual location on the palatal roots of maxillary second molars. The findings of this case report confirm the role of CEPs as a local contributing factor in localized chronic periodontitis.

The Use of Titanium Mesh in Sinus Augmentation

Sinus floor elevation is a clinical procedure to allow implantation in the posterior maxillary areas, in cases of reduced alveolar height. Numerous techniques and materials have been described during the last 2 decades. The aim of this article is to present an innovative technique for sinus lifting procedure. The use of a titanium mesh allows better stability of grafted materials and a more predictable result.

Predictability of simultaneous implant placement with sinus floor elevation in the severely atrophic posterior maxillae ; Comparison of lateral and trans-crestal approaches

Purpose The aim of this study is to evaluate the survival rates and analyze the stability of lateral approach and trans-crestal approach for maxillary sinus floor elevation of simultaneous implant placement. Materials and method 407 patients who have been treated in LivingWell dental hospital between 2003 to 2009 were selected. Lateral window technique, osteotome technique and sinus drill technique were used for sinus floor elevation procedure. A total of 714 implants-MP-1 HA coated implant(Tapered Screw VentTM, SplineTM, Zimmer, USA), FBR surfaced implant(Pitt-EasyTM, Oraltronics, Germany)-were placed in grafted maxillary sinus simultaneously. The autogenous bone or a combination with the allograft or alloplast was grafted into sinus. Sinus floor elevation was combined with vertical/horizontal onlay bone grafts to reconstruct the defect of alveolar ridge. Results The average preoperative height of the maxillary alveolar bone was 5.78mm(range: 0.4mm~12.5mm). 14 implants failed during the healing period(lateral approach: 4, trans-crestal approach: 10) and 3 implant failed after prosthetic loading(lateral approach: 2, trans-crestal approach: 1). The cumulative survival rate of implants after 6 years was 97.6%. Trans-crestal approach(97.4%) and lateral approach(97.9%) had similar survival rates. Conclusion The results indicate that the trans-crestal approach and lateral approach for maxillary sinus elevation is a acceptable method at atrophic maxillary posterior area.

Cervical enamel projections in unusual locations: A case report and mini-review.

Background: Periodontitis is primarily a bacteria-induced disease that can be modified by tooth-related local factors. Cervical enamel projections (CEPs) are a common tooth anomaly that can act as a contributing factor in the development of periodontitis. They are most commonly found at the buccal surfaces of mandibular molars. Methods: A 57-year-old female was referred to our clinic for treatment of chronic periodontitis. Clinical examination revealed moderate attachment loss that was localized to the palatal side of the maxillary secondary molars. The rest of the dentition was less affected, with a diagnosis of generalized slight chronic periodontitis. Initial non-surgical periodontal treatment was provided, followed by apically positioned flap surgery in the maxillary right and left posterior areas. At the time of surgery, CEPs were found where the periodontium was most affected. Results: Due to the fact that surgical intervention exposed the CEPs, they were not removed. After the active therapy, which resulted in inflammation resolution and maintainable probing depth, the patient was placed on a three-month recall for periodontal maintenance. Conclusions: This case report presents CEPs in an unusual location in the palatal roots of maxillary secondary molars. CEPs confirm their role as a local contributing factor in localized chronic periodontitis.

Treatment of oroantral fistula with autologous bone graft and application of a non-reabsorbable membrane

The aim of the current report is to illustrate an alternative technique for the treatment of oroantral fistula (OAF), using an autologous bone graft integrated by xenologous particulate bone graft. Acute and chronic oroantral communications (OAC, OAF) can occur as a result of inadequate treatment. In fact surgical procedures into the maxillary posterior area can lead to inadvertent communication with the maxillary sinus. Spontaneous healing can occur in defects smaller than 3 mm while larger communications should be treated without delay, in order to avoid sinusitis. The most used techniques for the treatment of OAF involve buccal flap, palatal rotation - advancement flap, Bichat fat pad. All these surgical procedures are connected with a significant risk of morbidity of the donor site, infections, avascular flap necrosis, impossibility to repeat the surgical technique after clinical failure, and patient discomfort. We report a 65-years-old female patient who came to our attention for the presence of an OAF and was treated using an autologous bone graft integrated by xenologous particulate bone graft. An expanded polytetrafluoroethylene titanium-reinforced membrane (Gore-Tex) was used in order to obtain an optimal reconstruction of soft tissues and to assure the preservation of the bone graft from epithelial connection. This surgical procedure showed a good stability of the bone grafts, with a complete resolution of the OAF, optimal management of complications, including patient discomfort, and good regeneration of soft tissues. The principal advantage of the use of autologous bone graft with an expanded polytetrafluoroethylene titanium-reinforced membrane (Gore-Tex) to guide the bone regeneration is that it assures a predictable healing and allows a possible following implant-prosthetic rehabilitation.

Study about the complications associated with implant surgery and prosthetic treatment

Purpose : The aim of this study was to compare surgical complications between simple implant placement and implant placement combined with complicated surgical procedures. We also evaluated prosthetic complications according to the specific types of prosthesis. Material and Method : A retrospective analysis of dental chart of patients who was performed implant therapy during the period from June 2003 to December 2005 was carried out. This study was performed on 408 patients (208 male, 200 female). In addition, 1671 implants were performed. Based on their medical record and radiographs, the authors evaluated surgical and prosthetic complications, surgical procedures accompanied at the time of implant, risk factors of implant failure etc. Result : Surgical complications were developed on 358 implants(21.4% on total placed implants) and wound dehiscence was most prevalent complication. On maxillary posterior area, surgical complications developed more frequently on implants with major surgery and showed a significant difference. And complication rate of implants accompanied with GBR was higher than that of simple implants placement and also showed significant difference. The implant supported prosthesis showed no statistical difference in the occurrence of complications according to the types of prosthesis, and food retention was the most common post-prosthetic complication. Also we speculated that length and width of implant showed significant correlation to the failure of implant primary osseointegration. Conclusion : Based on the result, clinician should provide more careful maintenance for patients with implant placement accompanied by complicated surgical procedure. And periodic maintenance for the patient is requested for long-term survival of implant therapy.

Evaluation of interdental space of the maxillary posterior area for orthodontic mini-implants with cone-beam computed tomography

Our objectives in this study were to measure in a group of patients the interradicular spaces between the maxillary second premolar and first molar, which is often used as placement sites for mini-implants, and to suggest simple guidelines for safe placement. Cone-beam computed tomography was used in 35 patients to measure interdental spaces and distances between the surface of the cortical bone and the closest interradicular area apically in 1-mm intervals in 9 axial images from the cementoenamel junction (CEJ). The cone-beam computed tomography data were analyzed by using anlaysis of variance (ANOVA) to evaluate the differences in interradicular distances, cortical bone surfaces, and narrowest interradicular spaces. A t test was also performed to evaluate sex and placement side differences. Interradicular space became wider toward the apical area; several axial planes showed statistically nonsignificant differences from the CEJ to the root, and the average distance from the surface of the cortical bone to the area of the closest interradicular space was over 5 mm in the most sections. Guidelines for safe placement are as follows: the initial point for mini-implant placement is near the mucogingival line (2-4 mm from the CEJ) and less than a 45 degrees apical angulation to the long axis of tooth, with a mini-implant diameter of 1.4 to 1.8 mm and length of about 6 mm (bone contact). A larger placement angle would increase the cortical bone contact; however, it is difficult to apply various traction materials and might increase the danger of maxillary sinus perforation.

The use of the buccal fat pad for guided bone regeneration in posterior maxilla: Review of the literature and report of 2 cases

For the successful guided bone regeneration(GBR) of maxillary bony defect, proper soft tissue coverage is one of the most important things. Soft tissue dehiscence can be most common reason of osseous reconstruction failure. If a vascular supply to the graft should not develop from the host tissue, then the graft may also foil. Both of these prerequisites can be aided by judicious use of the buccal fat pad(BFP). Many methods for adequate soft tissue coverage have been proposed and the use of the BFP is one of them. BFP is useful in posterior maxillary area, can cover larger area and have higher blood flow than other methods. so the use of the BFP may offer protection and early blood supply to maxillary bone graft. This report describes the history, anatomy, blood flow, and clinical usefulness with two clinical cases.

A retrospective study of the dental implants placed in the controlled diabetes mellitus patients

Purpose: The aim of the present study was to analyze 7-year cumulative survival rate (CSR, %) of dental implants in the controlled diabetic patients and to evaluate the influence of the position, diameter and length of fixture, bone quality, age, gender and the method of maxillary sinus elevation on the survival rate. Methods: The data of 342 placed implants in the 104 diabetic patients collected between 1995 and 2007 at the Department of Periodontology in Yonsei University Hospital were analyzed. Results: Seven-year CSR of the 342 dental implants in the 104 controlled diabetic patients was 96.5%. The survival rates of the placed implants according the position have no statistically significant difference. The survival rates according to the length or diameter of the fixtures have no statistically significant difference. The survival rates according to the bone quality were 100% (TypeⅠ), 97.1% (Type Ⅱ), 97.7% (Type Ⅲ) and 85.7%(Type Ⅳ). The difference between the survival rate of Type Ⅰ, Ⅱ and Ⅲ and that of Type Ⅳ was statistically significant. The survival rates according to patient gender were 96.8% (male), 95.5% (female). The survival rates according to patient age were 100% (≤59), 93.8% (≥60). The survival rates according to the method of sinus elevation in the maxillary posterior area were 96.8% (without sinus elevation), 92.9% (lateral approach) and 89.8% (crestal approach). Conclusions: Dental implants can be used successfully in the controlled diabetic patients. In case of upper posterior region which has poor bone density and older patients, the implant treatment should be more properly planed, executed, and followed-up. (J Korean Acad Periodontol 2009;39:311-320)

Clinical and histologic comparison of two different composite grafts for sinus augmentation: a pilot clinical trial

Sinus augmentation is a procedure used for augmenting insufficient bone height that is often observed in the maxillary posterior areas. Many different techniques as well as bone graft regimens have been suggested for performing this procedure. It was the goal of this study to compare, clinically and histologically, two different composite grafting regimens used for sinus augmentation. Five patients, needing a bilateral sinus augmentation to allow implant placement, were recruited for this study. Right sinuses were grafted with cortical bone (collected from overlying the sinus membrane) and bovine hydroxyapatite (HA), while the left side sinuses were grafted with overlying autologous bone plus a bioglass (BG) material. Bone core biopsies were taken at 6 months after sinus graft or at the time of implant insertion. A waiting period of 6 additional months was granted to allow healing, before prosthetic restoration and functional loading. The level of peri-implant bone was evaluated 12 months after loading. A comparative histomorphometric analysis was conducted and a statistical analysis was performed. All implants in both groups were functional after a 12-month loading period. No bone loss was observed radiographically or clinically in both groups. Histologic analysis revealed that both composite grafts had a high biocompatibility. In the bovine HA-containing group, minimal xenogenic graft absorption was noted. In contrast, BG group samples presented a high absorption rate with some remaining particles imbedded in new normal bone. Sinus augmentation using a combination of autogenous bone plus either bovine HA or BG is a predictable technique.