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.     

Preservation of the ridge and sealing of the socket with a combination epithelialised and subepithelial connective tissue graft for management of defects in the buccal bone before insertion of implants: a case series

Defects in the layer of buccal bone lead to its loss after tooth extractions. This requires hard tissue grafting before implants can be put in place. The aim of this study was to evaluate the stability of hard tissue grafts inserted at the same time as the teeth were extracted. Teeth had to be extracted because of defects in the buccal bone. Extractions were combined with preservation of the ridge using autogenous and artificial bone. A combination epithelialised and subepithelial connective tissue graft was used to seal the socket. Wound healing was assessed and the width of the alveolar crest was measured after hard tissue grafting and during insertion of the implants. We studied 39 patients (20 female, 19 male, mean (SD) age 41 (7.9) years) who had 43 teeth extracted together with preservation of the ridge. One patient failed to attend for placement of the implant. Thirty-nine implants were inserted 5.3 (0.4) months after preservation of the ridge. Two patients developed partial necrosis of the combination graft, but in all other cases primary wound healing was uneventful. In three cases the bone grafts failed to consolidate. The mean (SD) width of the alveolar crest was after bone grafting 6.80 (1.20) mm and during insertion of implants 5.65 (1.50) mm; the mean resorption of the bone grafts was 1.2 (1.1) mm. We conclude that bone grafting to rebuild buccal alveolar defects at the same time that the tooth is extracted, combined with a soft tissue graft to seal the socket, showed promising results and could be an alternative treatment to delayed hard tissue grafting.     

牙槽骨劈开术同期牙种植的临床应用

目的　评价牙槽骨劈开技术在口腔种植中应用的临床效果。方法　对116例缺牙区牙槽嵴高度大于12 mm,颊舌向厚度在3~5 mm之间的牙列缺损患者,行牙槽嵴劈开同期植入种植体治疗。共植入ITI种植体147枚,Replace种植体52枚。根据骨劈开术后间隙及唇颊侧骨壁厚度等不同情况选择植入或不植入自体骨、人工骨粉等修复手段。术后6月种植修复,定期随诊。结果　种植区软组织愈合好,无红肿,颊舌向牙槽骨较种植前明显增宽。术后除1颗种植体失败取出外,其余种植体稳固,种植修复体能正常使用。复诊时X线检查骨吸收≤1 mm。结论　骨劈开术使牙槽骨宽度在3~5 mm的病例有了一期种植的可能,是一种简单有效的增宽牙槽骨的方法。     

Onlay植骨技术在上颌前牙美学区种植修复中的应用

目的:评估Onlay植骨技术在上颌前牙美学区种植修复中的应用。方法:随机选取82例行种植修复术的患者,根据术前评估,给予患者合理的Onlay植骨技术及牙种植修复手术方案。观察患者植骨期间牙槽嵴骨量变化及美学指标变化情况,记录牙种植体存活率。结果:Onlay植骨术后3个月末牙槽嵴水平向骨量(7.84±0.42)mm、牙槽嵴垂直向骨量(11.65±0.85)mm和术后6个月末牙槽嵴水平向骨量(7.15±0.60)mm、牙槽嵴垂直向骨量(10.86±0.63)mm均显著高于植骨前骨量,P=0.035、0.039、0.035、0.040;牙种植修复术后3个月末PES(7.48±1.36)分、WES(7.56±1.09)分和术后6个月末PES(7.78±1.42)分、WES(7.82±1.51)分均显著高于术前评分水平,P=0.040、0.043、0.038、0.032;Onlay植骨术后,骨组织美观丰满,伤口愈合良好,未出现植骨坏死,种植体存活率高。结论:将Onlay植骨技术应用于上颌前牙美学区种植修复中,可显著改善种植区骨量不足的问题,骨愈合情况良好,种植体存活率高,值得推广使用。     

Utilization of mandibular tori for alveolar ridge augmentation and maxillary sinus lifting: a case report.

This article reports the utilization of mandibular tori as an alternative source of autogenous bone for ridge augmentation and maxillary sinus lifting to facilitate ideal implant placement. A patient presenting bilateral mandibular tori required replacement of a missing maxillary molar and a mandibular premolar. Both areas showed ridge deficiency that required bone augmentation before implant placement. Mandibular tori were used for horizontal augmentation of the mandibular alveolar ridge and vertical augmentation of the maxillary ridge by elevation of the maxillary sinus. Adequate new bone formation was noted in both areas 6 months after grafting. Bone formed in the grafted areas showed comparable clinical features to those of native bone. Implants were successfully placed and loaded, restoring esthetics and function. Within the limitations of this observation, mandibular tori can be successfully used for ridge augmentation and sinus lifting. However, further controlled studies are needed to determine the overall benefit of this source of autogenous bone.     

牙种植术钻孔骨碎作植骨的临床研究

目的:评价在牙种植术中,钻备种植窝时收集到的自体骨颗粒单独或与Bio-Oss人工骨混合作为骨移植材料应用的临床效果。方法:34例52枚牙种植术的病例分成四组。第一组(对照组)22枚植体,单纯植入种植体,种植区无植入自体骨或人工骨。第二组6枚植体,植入螺纹种植体后,在部分暴露的植体处植入Bio-Oss人工骨。第三组8枚植体,收集种植术中准备植体窝时,在各种钻针上的自体骨颗粒,植入种植体周骨量不足区域。第四组16枚植体,自各种钻针上收集到的自体骨颗粒与Bio-Oss人工骨混合,植入种植体周骨缺损区。记录I、II期手术种植体周围骨组织高度。结果:植入术后3-12个月,II期手术时,实验组有新生骨形成,第四组(即Bio-Oss人工骨与自体骨颗粒混合物植入组),新生骨形成的量较其余组别多。结论:研究表明牙种植术中钻备种植窝时收集到的自体骨颗粒可作为有效的植骨材料,这种简单的方法避免从他处手术获得自体骨,对扩大牙种植适应症有重要意义。RRRR     

Partial-thickness cortical bone graft from the mandibular ramus: a non-invasive harvesting technique

BACKGROUND: The conventional method of harvesting full cortical bone from the mandibular ramus was reported to have associated complications ranging from postoperative pain and swelling to impaired inferior alveolar nerve function. METHODS: A modified ramal bone harvesting technique is described in which partial cortical-type bone is harvested from the mandibular ramus and used for an autogenous bone graft. RESULTS: Partial-thickness cortical bone was harvested without paresthesia while reducing postoperative discomfort and complications. Sufficient bone was obtained for ridge augmentation and eventual implant placement. CONCLUSION: Non-invasive partial cortical ramal bone harvesting is a reproducible and predictable technique for preventing nerve damage while providing sufficient block bone needed for a dental implant.     

帐篷钉技术在牙槽嵴骨增量中的应用研究

充足的骨量是种植修复成功的关键因素,而临床上种植区骨量不足较为常见,导致难以获得理想的种植体植入方位。因此为确保种植修复的成功和稳定,牙槽嵴的修复与重建具有重要的临床意义。随着骨增量技术的发展,基于引导骨组织再生术基本原理的帐篷钉技术在临床上获得了显著效果,可以在减少甚至不使用自体骨的情况下完成牙槽嵴缺损的修复与重建。本文回顾了帐篷钉技术的发展历史,对其应用原理及条件、临床效果、相关并发症、技术要点以及注意事项等进行综述。     

Alveolar ridge preservation in the esthetic zone

In the esthetic zone, in the case of tooth extraction, the clinician is often confronted with a challenge regarding the optimal decision‐making process for providing a solution using dental implants. This is because, after tooth extraction, alveolar bone loss and structural and compositional changes of the covering soft tissues, as well as morphological alterations, can be expected. Ideally, the therapeutic plan starts before tooth extraction and it offers three options: spontaneous healing of the extraction socket; immediate implant placement; and techniques for preserving the alveolar ridge at the site of tooth removal. The decision‐making process mainly depends on: (i) the chosen time‐point for implant placement and the ability to place a dental implant; (ii) the quality and quantity of soft tissue in the region of the extraction socket; (iii) the remaining height of the buccal bone plate; and (iv) the expected rates of implant survival and success. Based on scientific evidence, three time‐periods for alveolar ridge preservation are described in the literature: (i) soft‐tissue preservation with 6–8 weeks of healing after tooth extraction (for optimization of the soft tissues); (ii) hard‐ and soft‐tissue preservation with 4–6 months of healing after tooth extraction (for optimization of the hard and soft tissues); and (iii) hard‐tissue preservation with > 6 months of healing after tooth extraction (for optimization of the hard tissues).     

Jawbone enlargement using immediate implant placement associated with a split-crest technique and guided tissue regeneration.

Five patients with sufficient vertical bone height but insufficient bone width for implant placement were chosen for treatment with a split-crest technique combined with guided tissue regeneration. The surgical technique involved splitting the alveolar ridge longitudinally in two parts, provoking a greenstick fracture. A chisel was then used to make a fine cut and spread apart the two cortical plates. Implants were then placed. Implants and defects were covered with expanded polytetrafluoroethylene membranes. Biometrical examination showed a gain in bone width, varying between 1 and 4 mm; maxillary sites showed greater ridge enlargement. Histologic examination showed regeneration of bone tissue between the two portions of the split crest. This membrane technique could be effective and predictable for horizontal ridge augmentation associated with immediate implant placement.     

The use of resorbable collagen membrane in conjunction with autogenous bone graft and inorganic bovine mineral for buccal/labial alveolar ridge augmentation: a pilot study

STATEMENT OF PROBLEM: No study provides human histologic evidence regarding the use of resorbable collagen membrane for a 2-stage localized alveolar augmentation procedure. PURPOSE: The purpose of this pilot study was to evaluate the potential of use of a resorbable collagen membrane in conjunction with an autogenous bone graft and inorganic bovine mineral (IBM) for labial/buccal alveolar ridge augmentation prior to placing dental implants.Material and methods Seven consecutively treated human patients participated in the study. All patients received labial/buccal alveolar ridge augmentation. An autogenous block graft was secured at the recipient site with fixation screws and a mixture of autogenous particulate with IBM was placed at the periphery. Resorbable collagen membrane was used as a barrier. Radiographic and laboratory measurements were made to quantify ridge augmentation and resorption rate. Preoperative and postoperative stone casts were used to quantify alveolar ridge augmentation. Volumetric evaluation was measured in mL whereas linear laboratory evaluation was measured in millimeters. Measurements were made 1 and 6 months after bone grafting. Histologic and histomorphometric analysis from the grafted area evaluated new bone formation, and osteoconductivity of IBM. RESULTS: For all patients Type II to III bone quality was achieved at the augmented sites. The implant survival rate was 100% at second-stage surgery. No complication was observed at the recipient sites. Radiographic evaluation revealed 4.65 mm labial/lingual augmentation, whereas laboratory analysis revealed 4.57 mm. Volumetric laboratory analysis demonstrated 1.00 (+/- 0.29) mL alveolar ridge augmentation 6 months after bone grafting and 13.79% resorption between months 1 and 6. Histomorphometric analysis revealed that on average, the area occupied by bone was 34.28% (range 24 to 50; +/-9.05),] soft tissue 46.00% (+/-9.20%; range 30% to 55%), and IBM particles 19.71% (+/-11.74%, range 3% to 42%). The proportion of the surface of the IBM particles in contact with bone was 47.14% (range 15% to 64%; SD 17.21%). CONCLUSIONS: Resorbable collagen membranes may be used as barriers for labial/buccal alveolar ridge augmentation procedures.     

A maxillary ridge-splitting technique followed by immediate placement of implants: a case report

Maxillary alveolar atrophy often limits the placement of dental implants. This article reports on a refinement of a technique for widening the atrophic ridge by splitting the alveolar bone longitudinally. Treatment of a patient with a severely resorbed edentulous maxilla is described. Six 4-mm wide by 13-mm long threaded Osseotite implants were placed immediately within the split ridge and surrounded with a mixture of autogenous tuberosity and bovine bone. The advantages of this technique for patients include less surgical trauma and condensed treatment time.     

Augmentation in two stages of atrophic alveolar bone prior to dental rehabilitation: a case report

AIM: The aim of this report is to describe a significantly deficient case of alveolar bone that was managed by alveolar bone augmentation using a technique of distraction osteogensis and onlay bone grafting prior to dental implant placement. BACKGROUND: Injury to the teeth and alveolar ridge of the maxillary anterior region can cause a severe alveolar ridge deficiency resulting in ridge atrophy and maxillary retrognathism. The loss of these teeth and alveolar bone together with fibrotic scar formation can result in adverse changes of the interarch space, occlusal plane, arch relationship, and arch form which complicates rehabilitation and can compromise the esthetic outcome. While implant dentistry has become a new paradigm in oral reconstruction and replacement of missing teeth, ideal implant positioning can be compromised by inadequate alveolar bone in terms of bone height, width, and quality of the bone itself. Correction of osseous deficiencies with ridge augmentation allows ideal implant placement and creates a more natural soft tissue profile which influences crown anatomy and esthetics. REPORT: A 20-year-old female presented with a complaint of poor esthetics resulting from oral injuries incurred in a traffic accident six years previously. In addition to a mandibular parasymphyseal fracture, five maxillary anterior teeth and the most of the alveolar ridge were lost. Clinical examination revealed severe loss of bone in the maxillary anterior region, an absence of a labial sulcus, loss of upper lip support, and a slight over eruption of the mandibular anterior teeth. In preparation for dental implants a distraction osteogenesis surgical procedure was done to lengthen the height of the alveolar ridge. After a three-month healing period, the width of the residual ridge was found to be insufficient for implant placement. To correct this deficiency, a bone graft of a cortiocancellous block was harvested from the chin and fixed to the labial aspect of the ridge. To facilitate revascularization, small perforations were made in the cortical bone of the alveolar ridge at the recipient site before cancellous bone retrieved from the donor site was gently placed between the bone block and the ridge. The patient was then appropriately medicated and healing was uneventful. After three months, the width of the residual ridge was assessed to be adequate for endosseous implants. SUMMARY: The clinical result reported here has shown several procedures may be necessary for the rehabilitation of a trauma patient. Distraction osteogenesis per se may not always satisfactorily improve the anatomical alveolar anatomy but it has advantages over other methods of augmentation. It can improve the height and also expand the soft tissue for further bone grafting. Augmentation of the alveolar bone with an onlay bone graft often provides the desired gain of bone, allows for the ideal placement of dental implants, and improves any discrepancy between the upper and lower arches.     

Biologic mechanical advantages of 3 different cranial bone grafting techniques for implant reconstruction of the atrophic maxilla.

PURPOSE: The purpose of this study was to test the mechanical capacities of 3 different bone grafting techniques in the atrophic maxilla when co-stabilized with dental implants. Reconstruction of the atrophic maxilla is a difficult clinical challenge and implants cannot be placed without adequate bone. METHODS: The biomechanical performance of 3 different grafting techniques was evaluated in vitro using a maxillary model, cadaveric cranial bone blocks, and dental implants. A maxillary model fabricated from polyurethane (sawbone) was selected as a substrate for this study because of consistency in shape, size, and mechanical properties. This anatomic model was more consistent than different cadaveric maxilla, where significant variation was found to exist among atrophic specimens. Cadaveric cranial bone graft blocks were secured to the model maxilla (sandwich, ridge only, and sinus inlay) with a dental implant. The strength of the implant/bone graft complex was tested to failure in an Instron machine (Instron Inc, Canton, MA). RESULTS: The 3 bone grafting methods showed significantly different deformation and strength characteristics. The sandwich technique enhanced resistance to deformation under higher imposed loads. The location of the graft influenced the overall mechanical performance (eg, the ridge onlay) and showed a significantly higher resistance to compressive loads applied toward the alveolar ridge (mastication force). CONCLUSION: The ridge onlay grafting procedures created a higher biomechanical tolerance to imposed load than the sinus grafting (sinus inlay). Sinus grafting, although successful, was not the most ideal location for immediate mechanical loading resistance when compared with ridge augmentation in this in vitro model.     

The effects of bone grafting material and a collagen membrane in the ridge splitting technique: an experimental study in dogs

Objectives: This study was designed to evaluate the effect of bone graft materials and collagen membranes in ridge splitting procedures with immediate implant placement using a dog model. Materials and methods: Mandibular premolars were extracted in five beagle dogs. After 3 months, ridge splitting and placement of three OsseoSpeed^? implants were performed bilaterally. The gaps between the implants were allocated according to the following eight treatment modalities; Group 1(no graft), Group 2 (autogenous bone), Group 3 (Bio‐Oss^® Collagen), Group 4 (Bio‐Oss^®), Group 5 (no graft+BioGide^®), Group 6 (autogenous bone+BioGide^®), Group 7 (Bio‐Oss^® Collagen+BioGide^®), and Group 8 (Bio‐Oss^®+BioGide^®). The dogs were sacrificed after 8 or 12 weeks and the specimens were analyzed histologically and histometrically. Results: The gaps between the implants were filled with the newly formed bone, irrespective of which of the eight grafting techniques was used. Group 1 revealed a significantly lower percentage of bone‐to‐implant contact (BIC) than Group 5 at 8 and 12 weeks (P<0.05). Group 1 showed the most prominent marginal bone loss (MBL) at 12 weeks (P<0.05). Regarding the use of membranes, Groups 1 and 2 showed significantly more MBL than Groups 5 and 6 at 12 weeks (P<0.05). Conclusions: After ridge splitting, if the gaps between implants were grafted or covered with collagen membranes, a higher percentage of BIC was obtained. Based on our results, we suggest that the use of bone graft materials and/or collagen membranes is better for the prevention of MBL after ridge splitting procedures. To cite this article:
Han J‐Y, Shin S‐I, Herr Y, Kwon Y‐H, Chung J‐H. The effects of bone grafting material and a collagen membrane in the ridge splitting technique: an experimental study in dogs.
Clin. Oral Impl. Res. xx , 2011; 000–000
doi: 10.1111/j.1600‐0501.2010.02127.x     

Use of titanium mesh for staged localized alveolar ridge augmentation: clinical and histologic-histomorphometric evaluation

The use of titanium mesh for localized alveolar ridge augmentation was evaluated by clinical, radiographic, laboratory, and histologic-histomorphometric evaluation. Seventeen patients participated in this study. All patients required localized alveolar ridge augmentation before placement of dental implants. An equal mixture of autogenous bone graft and inorganic bovine mineral (Bio-Oss) was used as a bone graft material. Autogenous bone graft was harvested intraorally. Titanium mesh was submerged for 8.47 months (SD 2.83). Impressions were taken intraorally before bone grafting, 6 months after bone grafting, and 6 months after implant placement. Impressions were used to measure the volume of alveolar ridge augmentation and provide linear laboratory measurements regarding the results of bone augmentation. Bone quality (type II-IV) was recorded during implant surgery. Standardized linear tomographs were taken before bone grafting and before implant placement. A biopsy was harvested with a trephine bur from the grafted area during implant surgery for histologic-histomorphometric evaluation. In all cases the grafted area had adequate bone volume and consistency for placement of dental implants. Early mesh exposure (2 weeks) was observed in 2 patients, and late exposure (>3 months) was observed in 4 patients. Volumetric laboratory measurements indicated 0.86 cc (SD 0.69) alveolar augmentation 1 month after bone grafting, 0.73 cc (SD 0.60) 6 months after bone grafting, and 0.71 cc (SD 0.57) 6 months after implant placement. This indicated 15.11% resorption 6 months after bone grafting, and no further resorption occurred after implant placement. Linear laboratory measurements indicated vertical augmentation of 2.94 mm (SD 0.86) 1 month after bone grafting, 2.59 mm (SD 0.91) 6 months after bone grafting, and 2.65 mm (SD 1.14) 6 months after implant placement. The corresponding measurements for labial-buccal augmentation were 4.47 mm (SD 1.55), 3.88 mm (SD 1.43), and 3.82 mm (SD 1.47). Radiographic evaluation indicated 2.56 mm (SD 1.32) vertical augmentation and 3.75 mm (SD 1.33) labial-buccal augmentation. Histomorphometric evaluation indicated 36.47% (SD 10.05) new bone formation, 49.18% (SD 6.92) connective tissue, and 14.35% (SD 5.85) residual Bio-Oss particles; 44.65% (SD 22.58) of the Bio-Oss surface was in tight contact with newly formed bone. The use of titanium mesh for localized alveolar ridge augmentation with a mixture of autogenous intraorally harvested bone graft and Bio-Oss offered adequate bone volume for placement of dental implants. Intraorally harvested autogenous bone graft mixed with Bio-Oss under a titanium mesh offered 36.47% new bone formation, and 15.11% resorption occurred 6 months after bone grafting.     

Vertical guided bone regeneration with bioabsorbable barriers

BACKGROUND: Guided bone regeneration (GBR) is a very useful surgical technique to increase limited alveolar bone for implant placement. The use of non-resorbable barriers is well established; however, bioabsorbable collagen membranes may simplify the surgical technique and make it more predictable. METHODS: Vertical ridge augmentation was performed on 11 patients at the time of implant placement. The part of the implant out of bone was covered with autogenous bone/graft, and a slow-resorption collagen membrane was placed on top. Gingival tissues were closed with horizontal mattress and interrupted sutures. Second-stage surgery was performed 4 to 6 months later, and healing abutments were placed. The length of the implant out of bone was determined at stage 1 and stage 2 surgeries on a periapical x-ray 1 year after implant load. Histology was obtained from one of the cases at second-stage surgery. RESULTS: Measurements revealed that the mean implant out of bone was 3.5 mm at stage 1 and 0.5 mm at stage 2. Mean bone gain was 3 mm, which represented 83% of the exposed implant at stage 1. One year after loading, implants showed a mean marginal bone loss of 1.4 mm. Minimal complications were detected, and only one case failed. Histology from one successful case showed new trabecular bone with large cellular marrow spaces in the regenerated area. CONCLUSION: Slow-resorption collagen membranes have the potential to promote vertical ridge augmentation when used with autogenous bone at the time of implant placement.     

Simultaneous flapless implant placement and peri-implant defect correction: an experimental pilot study in dogs

BACKGROUND: Minimally invasive implant surgery allows clinicians to place implants in less time, without extensive flaps, and with less bleeding and postoperative discomfort. The purpose of this study was to evaluate a new surgical technique by which implants are inserted in a deficient alveolar ridge using a flapless technique simultaneously with a peri-implant defect correction that is performed using a subperiosteal tunneling procedure. METHODS: Bilateral, horizontal defects of the alveolar ridge were created in the mandibles of five mongrel dogs. After 3 months of healing, one implant was placed on each side of the mandible by a flapless procedure. The exposed threads of the implant on one side of the mandible were covered with a 1:1 autogenous bone/xenograft mixture using a subperiosteal tunneling technique. Four months later, biopsies of the implant sites were taken and prepared for ground sectioning and analysis. RESULTS: All implants were well osseointegrated with the host bone. All of the peri-implant defects at the test sites were covered with tissue that resembled bone. In all specimens, a mixture of bone, connective tissue, and residual bone particles was observed in the graft area. In the control sites, where no graft was used, none of the exposed threads on any implants were covered with new bone. CONCLUSION: This preliminary report indicates the potential use of a minimally invasive flapless technique as a substitute for a more invasive implant placement and ridge augmentation procedure.     

Distraction osteogensis: a surgical option for restoring missing tissue in the anterior esthetic zone

Common causes of alveolar defects include bone resorption due to loss of teeth, infection, or trauma. There is often insufficient height or width of residual bone, and ridge augmentation may be required prior to implant placement. These defects range from small alveolar deficiencies to more complex, extensive bony defects. Various techniques are available for reconstructing alveolar ridges. Without augmentation, dental implants may have to be placed in anatomically unfavorable positions or have adverse angulations. These position/angulation compromises can lead to esthetic dissatisfaction, mechanical overload, and possibly implant loss. Both bone grafting and distraction osteogenesis are predictable methods for restoring missing tissue.     

Clinical results of alveolar ridge augmentation with mandibular block bone grafts in partially edentulous patients prior to implant placement

A group of 15 partially edentulous patients who needed alveolar ridge augmentation for implant placement, were consecutively treated using a two-stage technique in an outpatient environment. A total of 18 alveolar segments were grafted. During the first operation bone blocks harvested from the mandibular ramus or symphysis were placed as lateral or vertical onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 6 months of healing the flap was re-opened, the screws were removed and the implants placed. Twelve months after the first operation implant-supported fixed bridges could be provided to the patients. Mean lateral augmentation obtained at the time of bone grafting was 6.5 +/- 0.33 mm, that reduced during healing because of graft resorption to a mean of 5.0 +/- 0.23 mm. Mean vertical augmentation obtained in the 9 sites where it was needed was 3.4 +/- 0.66 mm at bone grafting and 2.2 +/- 0.66 mm at implant placement. Mean lateral and vertical augmentation decreased by 23.5% and 42%, respectively, during bone graft healing (before implant insertion). Mandibular sites showed a larger amount of bone graft resorption than maxillary sites. All the 40 implants placed were integrated at the abutment connection and after prosthetic loading (mean follow-up was 12 months). No major complications were recorded at donor or recipient sites. Soft tissue healing was uneventful, and pain and swelling were comparable to usual dentoalveolar procedures. A visible ecchymosis was present for 4 to 7 days when the bone was harvested from the mandibular symphysis. From a clinical point of view this procedure appears to be simple, safe and effective for treating localised alveolar ridge defects in partially edentulous patients.