Cortical tenting grafting technique in the severely atrophic alveolar ridge for implant site preparation

OBJECTIVES: Alveolar ridge augmentation using intraoral autogenous block grafts to augment localized alveolar ridge defects before implant placement is a predictable method. However, large severely atrophic edentulous segments may require extraoral donor sites. The purpose of this study was to evaluate the effectiveness of using intraoral cortical block grafts in combination with particulate human mineralized allograft, in a "tenting" fashion, to augment large atrophic alveolar ridge defects for implant placement. MATERIALS: This prospective case study evaluated augmentation in 10 consecutive patients with severely resorbed alveolar ridges missing a minimum of 4 adjacent teeth. Before augmentation, all grafted sites were deemed inadequate for placement of a standard 4-mm-diameter implant. Horizontal ridge augmentation was performed using autologous membranous cortical bone grafts from an oral donor site to tent out the soft tissue matrix and periosteum for the adjacent particulate allograft. The ridges were clinically evaluated 4 to 5 months after augmentation, and 42 implants were placed at that time. RESULTS: Implants were successfully placed at all grafted sites 4 to 5 months after the original graft date. Clinical evaluation of the grafted sites upon re-entry revealed uniform ridge anatomy. All edentulous segments had at least 2 implants placed of at least 4.0 mm diameter. In all, 42 implants were placed into grafted sites in the 10 patients. Implants were checked for osseointegration by using a counter torque of 35 N.cm. One implant failed to integrate. Mean follow-up was 22 months after implant placement. All augmented ridges had retained their functional and esthetic integrity at 1 year after original augmentation. CONCLUSION: Tenting of the periosteum and soft tissue matrix using a cortical bone block maintains space and minimizes resorption of the particulate allograft volume. In addition, bridging the cortical blocks with particulate bone avoids unaesthetic ridge defects between cortical block grafts in larger ridge defects. The result was a more uniform and esthetic alveolar ridge, capable of maintaining an implant-supported prosthesis. The technique offers predictable functional and esthetic reconstruction of large-volume defects without extensive amounts of autogenous bone. This offers a superior functional and esthetic result than with either cortical or particulate grafting alone.     

Clinical evaluation of particulate allogeneic with and without autogenous bone grafts and resorbable collagen membranes for bone augmentation of atrophic alveolar ridges

Objectives: The evaluate the clinical outcome of bone augmentation with the use of particulate mineralized freeze‐dried bone allograft (FDBA) with or without the addition of autogeneous bone chips, applied in a bi‐layered (BL) technique, covered by a resorbable cross‐linked collagen membrane. Material and methods: Fifty patients presenting with a vertical and/or lateral ridge deficiency of at least 3 mm were included: Group FDBA, N=27 patients, particulate FDBA was the only graft; and Group BL, N=23 patients, a BL bone grafting procedure where autogenous bone chips were the inner layer and FDBA the outer. Bone graft was covered with a ribose cross‐linked collagen barrier membrane. Ridge dimensions were clinically or radiographically (computerized tomography scan) measured at the time of the bone augmentation procedure and at implant placement or uncovering and the maximum linear vertical or horizontal calcified tissue gain was calculated. Statistical analysis consisted of linear regression analysis, with maximum bone gain being the dependent variable. Results: In the FDBA group, mean vertical bone gain was 3.47 mm (SD 1.25) and the horizontal, 5 mm (SD 1.28), while in the BL values were 3.5 mm (SD 1.2) and 3.6 mm (SD 1.72), respectively. Addition of autogenous bone does not appear to statistically significantly enhance the results. Spontaneous membrane exposure occurred in 24% of the cases and was the only variant that significantly influenced results (P<0.001). Conclusions: Large vertical and/or horizontal ridge deficiencies may be treated with FDBA and ribose cross‐linked collagen barrier membranes with good clinical outcome. No added effect of the application of a layer of autogenous bone in these bone augmentation procedures could be demonstrated. Spontaneous membrane exposure was the only parameter to affect the degree of new calcified tissue formation. To cite this article:
Beitlitum I, Artzi Z, Nemcovsky CE.
Clinical evaluation of particulate allogeneic with and without autogenous bone grafts and resorbable collagen membranes for bone augmentation of atrophic alveolar ridges.
Clin. Oral Impl. Res. 21 , 2010; 1242–1250.
doi: 10.1111/j.1600‐0501.2010.01936.x     

上颌前牙区骨挤压联合骨引导再生同期种植术的应用

目的：评价上颌前牙区骨挤压联合骨引导再生同期种植术的临床效果.方法：对14例上前牙缺失、牙槽骨厚度为3mm-4mm的患者,联合采用骨挤压、骨引导再生技术,植入Frialit-2种植体17颗,于植入后6个月行二期手术,同时测量牙槽嵴顶增宽的厚度,最终完成烤瓷冠修复.结果：本组共17颗种植体,术后均无明显并发症发生,牙槽嵴顶增宽的厚度平均为2.8mm±0.6 mm,修复完成后观察12-20个月,种植体行使功能良好,无一种植体松动或脱落.结论：对于上颌前牙区牙槽骨吸收的患者,采用骨挤压联合骨引导再生术后行种植体植入,可改善牙槽骨质量,获得满意的近期临床效果.     

Simultaneous sinus lifting and alveolar distraction of the atrophic maxillary alveolus for implant placement: a preliminary report

This article describes a procedure for performing simultaneous sinus lifting and alveolar distraction to augment an atrophic maxillary alveolus. This technique is a 1-stage operation that is indicated when the amount of native sinus floor bone is minimal (<5 mm). The technique is contraindicated when there is <2 mm of sinus floor,when a 2-stage operation is needed (sinus lifting, alveolar distraction osteogenesis). Postoperative complications are minimal.     

Intraoral onlay block bone grafts versus cortical tenting technique on alveolar ridge augmentations: a systematic review

Background To review systematically the bone gain and superficial resorption rate of the onlay block bone grafts versus the cortical tenting technique, as well as secondarily study the postoperative complications, implant survival and success rates, and peri-implant marginal bone loss.Material and Methods Following the recommended methods for systematic reviews and meta-analyses (PRISMA), an electronic search was performed in the PubMed (MEDLINE), EMBASE and the Cochrane Library of the Cochrane Collaboration (CENTRAL) databases to identify all relevant articles published up to March 2021 on onlay block bone grafts and cortical tenting technique.Results Eighteen papers complied with the inclusion criteria. In onlay grafts, the vertical bone gain mean was 4.24 mm, and resorption 20.91%; and 4.29 mm in the horizontal augmentation with a resorption of 10.28%. The complication rate was 14.8%. The implant survival and success rates were 100% and 92%; and the mean peri-implant bone loss ranged from 0.6 to 1.26 mm.In cortical tenting technique, the vertical bone gain mean was 6.17 mm and the resorption of 9.99%; and 5.55 mm in the horizontal augmentation with a 6.12% of resorption. The complication rate was 24.6%. The implant survival and success rates were 96.63% and 100%; and the mean peri-implant bone loss ranged from 0.27 to 0.77mm.Conclusions Despite the limitations, both techniques offer a predicTable way to reconstruct atrophic alveolar ridges, though the cortical tenting technique seems to achieve a greater bone gain and a lower surface resorption. Current evidence is still limited due to the inadequate follow-up, lack of information referred to methodological quality and sample attrition. Key words:Onlay graft, cortical graft, intraoral bone, augmentation procedure.     

Reconstruction of alveolar clefts with mandibular or iliac crest bone grafts: a comparative study

The aim of this study was to compare the results of treatment obtained with mandibular symphyseal and iliac crest bone grafts used for reconstruction of alveolar clefts. The study included 40 patients with unilateral cleft lip palate (UCLP): 20 consecutive patients whose defects were reconstructed with mandibular bone grafts (MBG) and 20 randomly selected UCLP patients who underwent reconstruction with iliac crest bone (ICB). The age at surgery varied from 8 to 13 years (mean age MBG group, 9.1 years; ICB group, 10.3 years), and the postoperative observation period varied from 12 to 33 months (mean, 19 months). Transverse expansion of the maxilla was not completed until after the bone grafting in the group of patients receiving MBGs, whereas it was completed before surgery in the ICB group. The observed marginal bone level on cleft-related teeth was similar in both groups. No periodontal complications were present in any of the patients, and the amount of attached gingiva was similar in both groups. In the MBG group, 15% of the canines were retained, whereas 20% of the canines were retained in the ICB group. The only complication that developed was in a patient from the MBG group, in whom a partial dehiscence of the donor site was observed. The results of this study demonstrate that reconstruction of alveolar clefts with MBG or ICB has a comparable prognosis. The use of MBGs in these patients has several advantages compared with ICB, including reduced operating time, reduced morbidity, reduced hospitalization time, and finally, a cutaneous scar at the iliac crest can be avoided.     

Anteroinferior distraction of the atrophic subtotal maxillary alveolus for implant placement: a case report

Most reports on alveolar distraction have been related to vertical distraction in the mandible and the maxilla. There have been few reports on horizontal or oblique alveolar distraction. A case of an atrophic subtotal maxillary alveolus distracted 10 mm anteriorly and 5 mm vertically, followed by the placement of 9 implants, is presented. A healthy, 55-year-old woman presented with a chief complaint of mobility of all maxillary teeth. All remaining 11 teeth except the maxillary left second molar were diagnosed as being involved with advanced marginal periodontitis, and were considered hopeless and subsequently extracted. Three months after extraction, a horizontal osteotomy was performed with a bone saw between the bilateral second premolar regions, extending vertically distal to the second premolars, without involving the maxillary sinuses. After confirming mobility of the alveolar bone, a distraction device was seated with titanium miniscrews and adhesive resin cement over the hard palate. After a 7-day waiting period, the maxillary alveolus was distracted anteroinferiorly 0.25 mm twice a day for 25 consecutive days. The distraction process was completed uneventfully. Postdistraction computed tomography demonstrated that the maxillary alveolus was adequately distracted to place implants in an ideal position. Nine endosseous implants were placed 4 months after seating the distraction device. All implants had good primary stability and were submerged. All implants osseointegrated, although 2 anterior implants were replaced due to disintegration resulting from transmucosal overloading of the interim removable prosthesis. No significant marginal bone resorption was seen around the implants 16 months after implant placement. It was concluded that alveolar distraction can be very useful for augmenting the atrophic alveolus, not only vertically but also horizontally or obliquely.     

Use of crestal bone for augmentation of extremely knife-edged alveolar ridges prior to implant placement: report of 3 cases.

A technique is presented for interforaminal lateral augmentation of mandibles with adequate bone height, but extremely knife-edged mandibular alveolar ridges (Class IV of Cawood and Howell's classification of residual ridges), in which the crestal portion of the knife-edged ridge is used as grafting material. Following an osteotomy and rotation of the grafts by 180 degrees, the grafts were fixed to the residual ridge below the osteotomy line by means of miniscrews. All grafts showed only mild resorption after a healing period of 3 months, and it was possible to place 4 implants in the now sufficiently wide host region.     

Sinus grafting with porous bone mineral (Bio-Oss) for implant placement: a 5-year study on 15 patients

The efficacy of Bio-Oss as a graft material for sinus floor elevation was studied in 15 patients. A total of 20 sinus augmentation procedures was performed, and 6 months later 57 implants were placed into the augmented sinuses. New bone formation was confirmed in biopsies of 3 patients (new bone: 21.08% +/- 7.25% after 6 mo, 27.55% +/- 4.88% after 12 mo; Bio-Oss: 39.17% +/- 4.36% after 6 mo, 27.01% +/- 11.64% after 12 mo). After a mean loading period of 4.0 +/- 0.5 years (range 3.2 to 4.8 y), 56 implants remained in place. This study confirms Bio-Oss's good osteoconductive properties.     

Particulate allogeneic bone grafts into maxillary alveolar clefts in humans: a preliminary report

The purpose of this study was to determine the ability of particulate allogeneic bone graft to adequately bridge unilateral maxillary alveolar clefts in humans. Twenty patients with unilateral alveolar clefts and oronasal fistula underwent alveolar cleft grafting with a clinically appropriate amount of particulate allogeneic bone. The grafted cleft area was followed radiographically for three to six months postsurgery. Although it was difficult to quantitate, it was both clinically and radiographically apparent at three months that bone bridging and filling of the cleft had occurred in 100% of the cases. From this study, it appears that allogeneic bone is a viable alternative for repairing alveolar clefts and that its use has a significant benefit to the patient by eliminating the morbidity of a second operative site.     

The sandwich osteotomy technique to treat vertical alveolar bone defects prior to implant placement: a systematic review

Clinical Oral Investigations - The aim of this systematic review was to investigate the predictability of the sandwich osteotomy technique to provide sufficient alveolar bone height for dental...     

Sinus floor elevation using a bovine bone mineral (Bio-Oss) with or without the concomitant use of a bilayered collagen barrier (Bio-Gide): a clinical report of immediate and delayed implant placement

Xenografts have been used extensively, either alone or in combination with autogenous bone, in sinus floor elevation techniques. However, controversy exists regarding the need to cover the lateral osteotomy site with a membrane. Also, the healing period before loading remains undefined when machined-surface implants are placed. Twenty-nine patients showing reduced bone volume in the posterior maxilla had 61 Br?nemark System implants placed in 30 sinuses augmented with a lateral osteotomy approach. Sinuses grafted with Bio-Oss and covered with a collagen membrane Bio-Gide (M+) received 29 implants, while grafted but uncovered sites (M-) received 32 implants. An immediate procedure was followed to place 41 implants and a staged procedure was used for 20 implants. Abutment connection was made in 2 distinct postoperative periods: 6 to 9 months and over 9 months. The patients were followed for an average of 22.4 months. The survival rate of the implants was dependent on the postoperative healing time and membrane presence. In case of the immediate procedure and in M- sites, when residual bone height was less than 5 mm, more failures occurred when the loading was done at 6 to 9 months than after 9 months. No failures occurred in the M- series when a staged approach was followed. The overall survival rate was 78.1% for the M- sites and 93.1% for the M+ sites. No failures occurred (0/35) in the control implants placed in adjacent native bone. Implant survival rate was related to the quality of the reconstructed cortical plate and to implant length. The concomitant use of a collagen barrier to cover the osteotomy site, when machined-surface implants were used in sinus grafting, seemed to improve the quality of the graft healing and survival rate of the implants loaded between 6 and 9 months after placement.     

The use of ramus autogenous block grafts for vertical alveolar ridge augmentation and implant placement: a pilot study

PURPOSE: This study presents a clinical, radiographic, laboratory, and histologic/histomorphometric analysis of the use of mandibular ramus block autografts for vertical alveolar ridge augmentation and implant placement. MATERIALS AND METHODS: Autogenous block autografts were fixed at the recipient site with fixation screws while a mixture of autogenous bone marrow and inorganic bovine material (Bio-Oss) was used at the periphery. All grafts appeared well incorporated at the recipient site during reentry surgery. RESULTS: Radiographic measurements revealed an average of 6.12 mm vertical ridge augmentation 1 month after surgery and 5.12 mm 4 to 6 months after surgery. Laboratory volumetric measurements revealed an average of 0.91 mL alveolar ridge augmentation 1 month after surgery and 0.75 mL 6 months postoperatively. Linear laboratory measurements revealed 6.12 mm of vertical ridge augmentation 1 month postoperatively and 4.37 mm 4 to 6 months after surgery. Histologic evaluation indicated signs of active remodeling in all the specimens. Histomorphometric analysis of the peripheral particulate bone indicated bone present at 34.33% of the grafted area, while 42.17% of the area was occupied by fibrous tissue and 23.50% by residual Bio-Oss particles. DISCUSSION: The results demonstrated the potential of mandibular block autografts harvested from the ascending ramus to maintain their vitality. Volumetric resorption rate of 17.58% and radiographic resorption rate of 16.34% were in accordance with previously published literature. Early exposure appeared to compromise the results, while late exposures did not affect the vitality of the block autografts. CONCLUSION: Mandibular block autografts can maintain their vitality when used for vertical alveolar ridge augmentation. Inorganic bovine mineral (Bio-Oss) can be used at the periphery of the block graft when mixed with autogenous bone marrow.