Vertical distraction osteogenesis of fibula transplant for mandibular reconstruction: a case report

Bone continuity defects in the mandible are caused by tumor surgery, trauma, infection, or osteoradionecrosis. Today, reconstruction of long-span mandibular defects with a free fibular flap is a routine procedure. However the bone height of the mandible after reconstruction is about half that of the dentulous mandible. Therefore, the deficiency in bone height makes implant placement impractical. In our case, because it was necessary to restore the mandibular height, a vertical distraction osteogenesis was performed on the grafted mandible of the patient who was referred to our clinic with a reconstructed mandible owing to a gunshot injury. As a result, the vertical discrepancy between the fibula and the native hemimandible of the patient was corrected. And the placement of dental implants was performed without any complications. In conclusion, we believe that the vertical distraction osteogenesis of free vascularized fibula flaps is a reliable technique that optimizes implant positioning for ideal prosthetic rehabilitation.     

Vertical distraction osteogenesis of fibular free flap in mandibular prosthetic rehabilitation: a case report

A 17-year-old boy underwent three cycles of chemotherapy and a subsequent mandibular resection for a Ewing's sarcoma of the left body and ramus. The mandible was immediately reconstructed with a microvascular osteomuscular fibular flap. One year after the mandibular reconstruction, distraction osteogenesis of the anterior portion of the fibula was performed using a Martin distractor according to the Hoffmeister technique. Bone lengthening was achieved at a rate of 1 mm/day by turning the device twice each day for 12 days. Subsequently, we waited for 70 days for bone consolidation to occur. After 6 additional weeks, five Maestro implants were placed into the distracted fibula. Bone specimens were retrieved with a trephine bur during implant placement. Mature bone was present after 70 days and after 6 months. The bone height increase was 12 mm.     

Peri-implant bone loss around posterior mandible dental implants placed after distraction osteogenesis: preliminary findings

BACKGROUND: The present study evaluates implant survival and peri-implant bone loss around posterior mandible dental implants placed at sites of distraction osteogenesis. METHODS: On removal of the distraction devices, 34 dental implants were inserted into 14 posterior mandible sites in 10 healthy, non-smoking female patients. Prosthetic treatment was performed 4 months after implant placement using fixed implant prostheses. After 6 to 16.5 months, periapical radiographs were taken and evaluated for peri-implant bone loss and radiolucency. The distance between the implant margin and the first visible bone-implant contact was measured on the mesial and distal aspects of the implants using imaging software. Radiographic dimensional distortion was corrected as a function of the known true dimension of the implant. RESULTS: Of the 34 implants placed, two (5.9%) failed to integrate at reentry surgery. Both were replaced and restored during the course of the study so that a total of 34 implants was followed for 12.1 +/- 3.8 months post-restoration and 16.1 +/- 3.8 months post-insertion. Mean loss of marginal bone height was 2.6 +/- 1.0 mm. During the follow-up period, radiolucent lines along the implant surface were absent. CONCLUSIONS: The mean peri-implant bone loss in areas of alveolar bone distraction was 1.9 mm/year. A high implant survival rate was observed.     

功能性颌骨重建61例临床分析

目的:评价采用多种骨瓣进行功能性颌骨重建的临床效果。方法:61例颌骨缺损患者,首先应用多种骨瓣重建颌骨的连续性,然后植入骨结合种植体,利用种植义齿重建患者的咀嚼和发音功能。61例患者中,男39例,女22例,平均年龄48岁(20～61岁)。游离髂骨瓣32例,血管化腓骨瓣21例,单纯牵引成骨重建颌骨7例,其他骨瓣1例。共植入种植体247颗。种植固定义齿修复29例,种植体支持的活动义齿修复32例。结果:种植义齿修复完成后平均追踪49个月(6～114个月),种植体脱落6颗。1例患者在修复完成2年后因肿瘤复发死亡(含4颗种植体,不计入存活种植体)。至最后复查,共237颗种植体仍在行使功能,累计5年存活率为95.95%。结论:应用游离髂骨瓣、血管化腓骨瓣重建颌骨的连续性后,植入骨结合种植体,能够有效地重建患者的咀嚼、发音功能,近期效果满意。     

牙槽骨垂直牵引成骨种植术的临床研究

目的 评价牙槽骨垂直牵引成骨技术在改善种植区域骨量中的可行性、临床效果及优缺点。方法 19例因肿瘤切除术或外伤等原因造成重度牙槽突垂直向骨缺损（缺损均大于10mm)患者接受了垂直骨牵引术，其中男性15例，女性4例，平均年龄35岁。常规行术前、术后及牵引前、后X线检查记录及取牵引器时直接测量牵引高度。安放牵引器7d后开始牵引，每日牵引1mm至设计高度。保留牵引器2－3个月，局麻下拆除牵引器，植入种植体。结果 19例中11例已完成种植上部结构修复，已植入种植体尚未完成上部修复6例，共植入种植体65枚。19例在牵引成骨后均形成理想新骨，平均新生骨的高度13mm。牵引区意外骨折2例，牵引区感染1例，植入种植体后感染1例。结论 牙槽骨垂直牵引术是解决重度骨量不足的有效的替代方法。     

Efficacy of Cancellous Block Allograft Augmentation Prior to Implant Placement in the Posterior Atrophic Mandible

Background: The present study evaluated the outcome of ridge augmentation with cancellous freeze‐dried block bone allografts in the posterior atrophic mandible followed by placement of dental implants. Materials and Methods: A bony deficiency of at least 3 mm, horizontally, vertically, or both, according to computerized tomography (CT) para‐axial reconstruction served as inclusion criteria. Implants were inserted after a healing period of 6 months. Bone measurements were taken prior to bone augmentation, during implant placement, and at second‐stage surgery. Marginal bone loss and crown‐to‐implant ratio were also measured. Results: Twenty‐nine cancellous allogeneic bone blocks were placed in 21 patients. The mean follow‐up was 37 months. Bone block survival rate was 79.3%. Mean horizontal and vertical bone gains were 5.6 and 4.3 mm, respectively. Mean buccal bone resorption was 0.5 mm at implant placement and 0.2 mm at second‐stage surgery. A total of 85 implants were placed. Mean bone thickness buccal to the implant neck was 2.5 mm at implant placement and 2.3 mm at second‐stage surgery. There was no evidence of vertical bone loss between implant placement and second‐stage surgery. Implant survival rate was 95.3%. All patients received a fixed implant‐supported prosthesis. At the last follow‐up, the mean marginal bone loss was 0.5 mm. The mean crown‐to‐implant ratio was 0.96. Conclusion: Implant placement in the posterior atrophic mandible following augmentation with cancellous freeze‐dried bone block allografts may be regarded as a viable treatment alternative.     

血管化腓骨重建下颌骨后用腓骨残端游离移植及牙种植的可行性研究

目的: 探讨利用残余腓骨增加下颌骨缺损腓骨重建患者垂直骨高度的临床效果。方法: 选择12例下颌骨缺损血管化腓骨重建后拟行种植牙修复的患者,利用腿部残余腓骨段进行垂直骨增量,同期或延期植入种植体并最终完成牙列修复,对术后骨吸收情况和种植体稳定性、存留率等数据采用SPSS 19.0软件包进行统计分析。结果: 术后6个月,近中骨块和远中骨块的吸收量分别为（0.94±0.18）mm和（0.89±0.15）mm;术后12个月,吸收量分别为（1.16±0.21）mm和（1.07±0.17）mm。种植体植入6个月和12个月后,ISQ值分别为（67.25±6.43）和（71.08±4.89）;边缘骨吸收量在植入术后6个月和12个月分别为（0.65±0.12）mm和（0.76±0.18）mm。术后1年种植体存留率为87.1%。结论: 非血管化腓骨具有可靠的抗吸收能力,在下颌骨缺损重建术后垂直骨高度不足的情况下,可为种植体植入提供充足骨量,并维持长期稳定性和存留率。     

Distraction of scarred soft tissue before secondary bone grafting. A case report.

Mandibular distraction was performed to restore oral function in a 52-year-old man with tongue cancer, in whom a mandibular fracture developed after marginal resection of the mandible. The fracture caused the mandibular dental arch to be shorter than the maxillary arch. An external fixation device was attached to the collapsed mandible. The mandibular soft tissue was expanded by 32 mm. After gradual distraction, a vascularized iliac bone graft was transferred to the lengthened space. Subsequently, vestibuloplasty was performed and implants were inserted. A normal appearance, acceptable occlusion and satisfactory oral function were achieved.     

Overcorrection in vertical alveolar distraction osteogenesis for dental implants

A decrease in bone height following alveolar distraction osteogenesis (DO) before implant placement is common, and can be severe when alveolar DO is performed soon after surgical intervention. The aim of this study was to investigate the decrease in bone height after vertical alveolar DO and determine the need for overcorrection with implant placement. Thirty-five patients (17 males and 18 females, mean age 43.9 years) underwent 38 procedures with successful placement of 141 dental implants. Alveolar ridge height was evaluated using digital orthopantomographic radiographs taken shortly after the end of distraction, at consolidation and before implant placement. The mean distraction was 9.7 mm. The total vertical alveolar bone decrease was 2.1mm (21%) during the consolidation period and 3.6mm (37%) at implant placement. Although the 20 sites with a healthy alveolus (surgery >6 months) had bone reductions of 1.5 and 2.5mm (15 and 25%) the 18 sites at which alveolar DO was performed within 6 months (mean 3.0) of surgical intervention had much greater bone loss of 2.7 and 4.8mm (28 and 50%), respectively ((**)P<0.01). These results indicate that any alveolar DO protocol should include a waiting period after the surgical intervention, as well as consider an overcorrection of more than 25% within the limits of the applied surgical protocol.     

即刻植骨同期种植体植入修复下颌骨缺损

目的 :探讨下颌骨缺损即刻植骨同期种植的可行性。方法 :对 6例下颌骨部分切除的患者 ,行下颌骨缺损即刻植骨同期种植术。其中 2例行血管化腓骨双层折叠移植 ,另 4例为非血管化髂骨移植。同期植入种植体共 19颗。结果 :6例术后均一期愈合 ,X线显示种植体周围骨结合正常。结论 :下颌骨缺损血管化和非血管化骨移植同期种植术是可行的 ,但由于同期种植的复杂性 ,要求在适应症的选择及手术操作上应更加严格     

Two-stage reconstruction of the severely deficient alveolar ridge: bone graft followed by alveolar distraction osteogenesis

Distraction osteogenesis for the augmentation of severe alveolar bone deficiency has gained popularity during the past two decades. In cases where the vertical bone height is not sufficient to create a stable transport segment, performing alveolar distraction osteogenesis (ADO) is not possible. In these severe cases, a two-stage treatment protocol is suggested: onlay bone grafting followed by ADO. An iliac crest onlay bone graft followed by ADO was performed in 13 patients: seven in the mandible and six in the maxilla. Following ADO, endosseous implants and prosthetic restorations were placed. In all cases, the onlay bone graft resulted in inadequate height for implant placement, but allowed ADO to be performed. ADO was performed to a mean total vertical augmentation of 13.7 mm. Fifty-two endosseous implants were placed. During a mean follow-up of 4.85 years, two implants failed, both during the first 6 months; the survival rate was 96.15%. In severe cases lacking the required bone for ADO, using an onlay bone graft as a first stage treatment increases the bone height thus allowing ADO to be performed. This article describes a safe and stable two-stage treatment modality for severely atrophic cases, resulting in sufficient bone for implant placement and correction of the inter-maxillary vertical relationship.     

Vertical distraction of a free vascularized osteocutaneous scapular flap in the reconstructed mandible for implant therapy

This paper describes a case of vertical distraction osteogenesis of a free vascularized osteocutaneous scapular flap in the reconstructed mandible before implant therapy. The patient was a 67-year-old woman with squamous cell carcinoma of the right lower gingiva. She underwent segmental mandibulectomy for tumor ablation and reconstruction with an osteocutaneous scapular flap. The distraction protocol, clinical course and implant therapy are presented. Through this procedure, the bone height of the scapular graft increased by 10mm. Implants with adequate length could be placed in the distracted area. Two years after masticatory loading, the condition of these implants was stable. Vertical distraction osteogenesis of the scapular flap was considered effective when performed before implant therapy, to facilitate postoperative functional and esthetic restoration after tumor resection.     

Functional and esthetic rehabilitation after mandibular resection in a child using a tooth/implant-supported distraction device: a case report

After resection and autogenous bone grafting in infancy and childhood, hypotrophy of the concerned jaw can often be observed. A 6-year-old male patient with osteogenic sarcoma was treated with partial resection of the mandible from the left first molar to the right first premolar. The aim was to rehabilitate the patient functionally and esthetically as he grew. At the age of 16, after the placement of 4 Br?nemark System implants in the consolidated autogeneous bone graft, the patient was treated with horizontal distraction osteogenesis. A new and unconventional type of individual tooth/implant-supported distraction device was used to lengthen the mandible by 16 mm. The implants placed to support the device were later used for prosthodontic rehabilitation. Progress in bone reconstruction, plastic coverage, and implant dentistry, as well as distraction osteogenesis, have enabled the compensation of functional and esthetic impairments caused by resection, especially in infants and young children.     

Histologic and radiographic evidence of vertical ridge augmentation utilizing distraction osteogenesis: 10 consecutively placed distractors

BACKGROUND: Vertical ridge augmentation for dental implant placement is one of the greatest challenges facing the surgeon. Inadequate vertical bone compromises the implant positioning and resulting restoration. The cleansibility, esthetics, and mechanical properties of the restoration can all be compromised. While the technique of distraction osteogenesis has been successfully employed for long bone applications for over 40 years, it has only recently been introduced as a technique for vertical ridge augmentation prior to dental implant reconstruction. METHODS: In this study, the placement of 10 consecutive distractors in 7 patients was evaluated. The surgical technique, latency period, distraction rate, and consolidation period are reviewed. RESULTS: The technique of distraction osteogenesis resulted in an average vertical augmentation of 7 mm, with a range of 5 to 9 mm. There were no complications affecting the outcome of the distraction procedure. No failures have occurred to date in the 16 implants that were placed and loaded following distraction. CONCLUSIONS: In summary, clinical, histologic, and radiographic evidence of consistent vertical bone augmentation was found with this technique of distraction osteogenesis for vertical ridge augmentation.     

Mikro- und Makrodistraktion am Kiefer

Vertical distraction osteogenesis (VDO) has been developed by our study group to move dentulous and edentulous segments of the alveolar process vertically with a device in microplate-design. Besides these techniques of vertical distraction of the atrophic alveolar crest some further modifications as Micro- and Macrodistraction are available. Microdistraction can be used in localised small defects of the alveolar crest with microplates and screws of 1.0 mm ¶in diameter. In a pilotstudy we ¶could treat 6 patients especially after traumatic bone loss of the alveolus. The lengths of the segments were 12.6 mm, the vertical distraction rate was 9.2 mm in average. Macrodistraction we call the distraction of the severely resorbed mandible in order to rebuild the vertical dimension of the weakened mandible. Vertical distraction osteogenesis of 13.6 mm was completed successfully in five patients with large segments of 119 mm lengths in average in a sandwich-technique. With a solid 2.3 basic plate a secure stability of the weakened mandible could be achieved. In contrast to bone transplantation an earlier mineralisation in the vertically distracted area could be seen by radiological examination and biopsy. We could insert dental implants in both pilot groups 3 months after distraction procedure. Main advantages of vertical distraction osteogenesis are: 1. No bone harvesting, 2. decreased resorption, 3. lower morbidity compared with conventional techniques, 4. lower infection rate and 5. feasibility to insert dental implants 3 months after distraction procedure, 6. gain of soft tissue     

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.     

Bone defect formation during implant placement following alveolar distraction

PURPOSE: This retrospective study was designed to evaluate the volume of hard tissue generated at the time of implant placement in distracted alveolar bone. MATERIALS AND METHODS: All patients who underwent distraction osteogenesis between 2000 and 2003 were included. The preoperative bone height, amount of distraction performed, and presence or absence of complications affecting implant placement were recorded. The augmentation achieved was correlated with insufficient bone formation using the Spearman correlation and the Fisher exact test. RESULTS: The study included 43 implants placed in 17 cases of alveolar distraction. Of the 34 implants placed in bone augmented by 4.5 to 6.5 mm, bone defects were observed with 12. All 9 implants placed in ridges augmented by 7 to 10.5 mm demonstrated a bone defect. The "defect" and "no-defect" implant groups differed significantly with respect to preoperative bone height and amount of distraction performed (P < .001 for both). Significantly more defects were formed in bone augmented by > 25% compared to bone augmented by < 25% (P < .001). CONCLUSIONS: When considering distraction osteogenesis, augmentation of up to 25% of the initial bone height seems more predictable and less likely to be associated with complications at the time of implant placement. In distractions greater than 25% of the original height, additional treatment should be considered.     

Distraction osteogenesis assisted by tissue engineering in an irradiated mandible: a case report

Distraction osteogenesis (DO) can provide predictable bone regeneration without grafting procedures but requires long treatment time and forms less bone transverse to the direction of distraction. To promote 3-dimensional bone formation and shorten the consolidation period, tissue-engineered osteogenic material (injectable bone) was applied in a patient who was being treated with vertical DO with an osteocutaneous fibular flap to reconstruct the mandible. The material, which comprised autologous mesenchymal stem cells culture-expanded then induced to be osteogenic in character and platelet-rich plasma (PRP) activated with thrombin and calcium chloride, was infiltrated into the distracted tissue at the end of distraction and injected into a space created labially with a titanium mesh at implant placement. The infiltration contributed to full consolidation of the regenerate for 3 months, and the injection thickened the regenerated ridge and bridged a gap between the native mandible and distracted fibula. The reconstructed mandible was expanded from 10 mm to 25 mm in height despite a lacerated and opened labial periosteum in the distracted area. Six implants 18 mm in length were placed and subsequently achieved osseointegration. The cutaneous flap covering the implants was trimmed, and the palatal mucosa was transplanted to the regenerated ridge for vestibuloplasty. These raw surfaces were covered with PRP; within 3 weeks, they had attained an epithelium. The implants have supported a fixed prosthesis with adequate surrounding bone and attached mucosa. DO was assisted by tissue engineering and became effective in restoring the compromised mandible.     

Staged reconstruction of the severely atrophic mandible with autogenous bone graft and endosteal implants.

PURPOSE: Vastly different surgical techniques have been advocated for osseous reconstruction of the severely atrophic mandible. Endosseous implants placed in autologous bone grafts have been proposed to minimize graft resorption and restore function; however, sufficient bone must exist to support the implants and prevent pathologic fracture. The purpose of this retrospective analysis was to assess the efficacy of autologous bone grafting and the subsequent placement of endosteal implants as a staged procedure in patients with severely atrophic mandibles. MATERIALS AND METHODS: The records of all patients presenting to The University of North Carolina for treatment from 1997 to 1999 with atrophic mandibles (vertical mandibular height <7 mm as measured on panoramic radiographs in at least 1 site at the mandibular midline and at the thinnest portion of the mandibular body) were reviewed. Bone height was assessed preoperatively, immediately postoperatively, at the time of implant placement (4 to 6 months), and again at 12 and 24 months after bone grafting from posterior iliac crest to the mandible via an extraoral approach. Five endosteal implants were subsequently placed in each patient as a delayed procedure 4 to 6 months after bone grafting, and prosthetic rehabilitation was completed with implant supported prostheses. RESULTS: Fourteen consecutive patients were identified with a median preoperative bone height of 9 mm (interquartile range, 25th to 75th percentile [IQ], 7 to 10 mm) in the mandibular midline and 5 mm (IQ, 2 to 5 mm) in the body region. There were no perioperative complications. Median estimated blood loss during the bone graft procedure, as estimated by the surgeon and the anesthesiologist, was 300 mL (IQ, 150 to 1,100 mL), and 1 patient required blood transfusion secondary to symptomatic anemia. The mean loss of vertical bone height after grafting and during the 4 to 6 months before implant placement was 33%. After implant placement and at 12 months, the vertical bone loss was negligible in the implant-supported region and less than 11% in the body region. CONCLUSION: Reconstruction of the severely atrophic mandible using autogenous corticocancellous bone grafts followed by placement of osseointegrated implants in 4 to 6 months can restore and maintain mandibular bone sufficient to support implants and facilitate successful restoration of occlusion. A prospective study is planned to identify predictors of successful outcomes compared with other surgical/prosthetic treatment.     

Horizontal distraction of the anterior maxilla in combination with bilateral sinuslift operation--preliminary report

In many cases alveolar ridge atrophy causes severe alveolar ridge deficiency in horizontal and vertical direction. In cases of severe atrophy of the edentulous maxilla a maxillary retrognathism results. In this article, a new technique of solving this problem prior to implant placement is described. In six patients with severe atrophy of the edentulous maxilla a sinuslift operation and placement of dental implants were carried out in the posterior maxilla. In the anterior part of the maxilla a segmental split osteotomy and placement of two miniplate distractors were performed. One week after surgery distraction started with a distraction speed of 0.5 mm a day until a clinical correct position of the anterior maxilla resulted. Then, the stabilisation period of 12 weeks followed before the distractors were removed and two to four implants were placed in the anterior distracted maxilla. After a second healing period of 4 months the implants were used for loading by a fixed prosthetic superstructure. Six patients were treated by this regime and 58 implants were placed. All implants were loaded by a fixed prosthesis. Distraction was performed without disturbances. Three months after healing new bone was formed in the distraction gap. There was no implant loss. An aesthetic satisfying superstructure with good red and white aesthetics was achieved together with a correct interalveolar relation. Distraction of the anterior part of the maxilla in combination with sinuslift operation is an alternative technique for correction of interalveolar incongruences in the edentulous maxilla and augmentation prior to implant placement.