冷冻自体下颌骨复合髂骨移植延期种植后种植体周围骨密度变化初探

目的:了解自体冷冻下颌骨复合髂骨移植延期种植后种植体周围骨密度的变化情况。方法:选择16只杂交狗为对象,液氮(-196℃)作为致冷剂,分别在动物双侧下颌骨体部制备骨缺损。左侧缺损行冷冻自体下颌骨骨块的原位再植并结合髂松质骨移植(复合移植组,composite transp lantation group,CTG),右侧缺损行自体髂骨块移植(髂骨移植组,iliac transp lantation group,ITG)。术后观察两类骨移植后的伤口愈合情况及骨新生与骨密度变化,术后3个月分别在两类骨块上植入IMZ(TPS种植体,每侧1枚,种植体植入后3、6、9、12周分别处死4只动物取材,通过标本的骨密度扫描进行种植体周围骨密度评价。结果:ITG种植体周围的骨密度均小于CTG,但随着时间的延长,这种差异逐渐缩小,到种植后12周时,这种差异已不明显。结论:骨密度测量结果提示,延期植入的牙种植体可与冷冻自体复合下颌骨形成良好的骨整合。骨密度值可以作为评价种植体周围骨整合情况的一个指标。     

非血管化髂骨和下颌骨与钛种植体结合的比较研究

目的 :研究非血管化髂骨和下颌骨与钛种植体结合的组织学特点。方法 :12只杂种犬随机分为 6组。切取 15mm× 5mm的下颌骨骨质 ,将骨块移植于对侧下颌骨人工骨缺损区 ,然后切取同样大小的髂骨骨块 ,移植于下颌骨骨缺损区 ,同时植入 2枚钛种植体 ,用种植体固定骨块。术后不同时间点取材 ,组织学观察。结果 :髂骨移植后早期以溶解坏死为主 ,6周时开始重建 ,种植体为混合界面 ;12周时改建基本完成 ,种植体形成骨结合。而下颌骨移植后早期移植骨吸收不明显 ,只是哈佛氏管扩大 ,与种植体界面间未见新骨形成 ;12周时移植骨内出现新生骨 ,骨吸收停止 ,种植体为混合界面 ,界面有不成熟的新生骨沉积 ,新骨与原骨结合不紧。 18周 ,种植体形成骨结合。 2 4周 ,移植的髂骨和下颌骨与骨床均融为一体 ,下颌骨与髂骨相比整体致密。结论 :髂骨与下颌骨移植后的修复过程及它们与钛种植体的骨结合过程不同 ,但均能形成骨性结合。下颌骨与种植体形成骨结合的时间比髂骨长     

深冷冻异体骨复合自体髂骨修复免下颌骨缺损的实验研究

目的　研究深冷冻异体骨 (deep frozenallograft,DFA)复合自体髂骨 (autogeneicilium ,AI)移植愈合过程的机理和特点。方法　在 2 0只大白兔的一侧下颌骨缺损内植入深冷冻异体骨复合自体髂骨移植材料 ,另一侧设自体骨对照。植入后 2周、4周、8周、12周 ,行大体标本、X线摄片、X线图象分析骨痂面积与骨痂灰度、组织学及扫描电镜观察骨形成的情况。结果　大体标本 :2周 ,对照组的移植骨愈合优于实验且 ;4、8、12周两组基本相似。X线摄片及组织学 :2周 ,实验组缺损可见自身成骨现象 ;4周形成骨小梁 ;8、12周骨质重建。X线图象分析骨痂面积与骨痂灰度 :实验组与对照组无明显的统计学差异 (P >0 0 5 )。扫描电镜 :实验组与对照组的成骨无差异。结论　深冷冻异体骨复合自体髂骨移植的愈合过程与自体骨相似 ;其成骨表现为骨引导成骨和骨诱导成骨 ,爬行替代是骨块移植愈合的主要方式     

自体冷冻病变骨-髂骨复合移植修复下颌骨缺损的临床研究

目的：采用自体冷冻病变骨—髂骨复合移植修复下颌骨缺损，对手术方法、优缺点及相关功能性义齿修复进行评价。方法：对1994年10月。2002年9月在我院行自体冷冻病变骨—髂骨复合移植修复下颌骨缺损的29例患者进行随访研究，根据临床检查、下颌曲面断层片及病人的满意程度对手术效果进行评估。结果：除2例切口感染、术后给予换药延期愈合外，其余切口均一期愈合，面部外形、口腔功能恢复满意。结论：自体冷冻病变骨—髂骨复合移植修复下颌骨缺损，是修复口腔功能及面部外形的有效方法。     

下颌骨缺损自体骨移植术后种植修复

目的：下颌骨缺损自体骨移植术后采用种植义齿修复。方法：6例髂骨移植患者，3例直接植入种植体；2例经颌骨骨块上置法植骨后植入种植体；1例经牵引成骨术增高牙槽突后植入种植体。2例腓骨移植患者，分别经腓骨上置法移植和牵引成骨术增高牙槽突后植入种植体。结果：8例患者最终都植入种植体，其中3例已完成上部义齿修复。结论：下颌骨缺损自体骨移植术后，常有牙槽突骨量不足，需行牙槽突Ⅱ期重建。上置法植骨和牵引成骨术能成功地重建牙槽突缺损骨量。     

带血管髂骨瓣移植同期种植体植入整复节段性下颌骨缺损

目的：利用血管化髂骨移植同期种植体植入早期整复节段性下颌骨缺损。方法：对5例下颌骨肿瘤患者于肿瘤切除后采用血管化的游离髂骨移植同期植入骨内种植体，术后6个月行Ⅱ期手术、义齿修复。结果：移植骨存活，植入的13枚种植体均与移植骨形成骨结合。义齿修复后随访6～48个月，种植体无松动、脱落．种植体颈部未见明显的骨质吸收。患者外形、咀嚼功能恢复满意。结论：采用该方法可早期整复节段性下颌骨缺损，运用时需注意种植体植入位置准确。     

非血管化髂骨移植同期种植重建下颌骨节段缺损的临床研究

目的：研究非血管化髂骨移植同期种植重建下颌骨节段缺损的方法及临床效果。方法：选取下颌骨节段缺损的病人，通过非血管化髂骨移植建立下颌骨连续性，同期植入牙种植体。结果：移植的骨块成活，植入的种植体可以实现骨结合并完成种植义齿修复，行使功能。结论：此方法可以实现下颌骨的功能重建。     

自体髂骨游离移植同期人工牙种植修复下颌骨缺损二例报告

两例因下颌骨良性肿瘤行下颌骨部分切除的病例，采用自体髂骨游离移植，同期骨内种植体植入，用以修复颌骨缺损及牙列缺损，治疗效果良好，为非血管化移植骨上同期植入牙种植体可以达到骨愈合提供了直接证据。     

纯钛种植体与非血管化髂骨骨结合的组织学观察

目的：研究纯钛种植体和非血管化髂骨块的骨结合情况。方法：10只杂种犬被随机分成5组，分别切取两侧游离髂骨移植于对侧，移植骨内同时植入钛种植体，术后不同时间点取材，组织学观察。结果：3周时，移植骨以吸收和坏死为主，6周时有新骨形成，9周时新骨形成的数量增加，12周时移植的骨块成活，骨组织改建完成，植入的钛种植体和移植的髂骨块之间无软组织介入，标志种植体与移植骨之间骨结合完成。结论：在本实验条件下，钛种植体和非血管化髂骨块可以形成完全骨结合。     

自体髂骨游离移植同期种植体植入修复骨量不足区牙缺失的动物实验研究

目的:利用自体髂骨游离移植一期植入种植体的动物实验研究,揭示自体髂骨游离移植同期植入种植体的愈合过程,为临床工作提供理论依据和借鉴。方法:选择16只健康成年雄性日本大耳白兔,在双侧髂骨制备髂骨缺损模型,游离移植自体髂骨,并同期分别在双侧髂骨植骨区及非植骨区植入自制圆柱状羟基磷灰石种植体。随机分成4组,每组4只。术后2周、4周、8周、12周各处死一组动物,切取标本。进行大体标本观察,放射线、组织学(脱钙HE染色)、扫描电镜检查、力学测试。结果:大体标本观察见各组种植体和髂骨结合紧密。肉眼见种植体和髂骨之间多为骨性结合,仅2周标本及4周实验组标本一些区域可见一薄层纤维样组织。放射线检查:2周标本可见有放射线透射区,实验组密度稍低于对照组密度;余各组种植体周围均未见明显的放射线透射区;4周标本实验组密度稍低于对照组;8周标本、12周标本实验组密度与对照组密度基本无差别。组织学及扫描电镜检查实验组与对照组种植体均与骨质形成不同程度的骨结合;对照组种植体比实验组形成更好的骨结合;各组种植体4周、8周、12周依次形成更好的骨结合。力学测试(反向推出实验)显示2周、4周、8周、12周骨结合实验组最大负荷分别是66.3N/cm2、143.9N/cm2、194.6N/cm2、248.3N/cm2。对照组最大负荷分别是108.6N/cm2、229.2N/cm2、307.1N/cm2、377.6N/cm2。结论:自体髂骨游离移植同期种植修复骨量不足区牙缺失是切实可行的修复方法。     

冷冻自体下颌骨复合髂骨移植的超微结构研究

目的：通过扫描电镜、透射电镜观察，了解冷冻自体下颌骨复合髂骨移植的愈合过程及机理。方法：8只健康家兔实施冷冻自体下颌骨复合髂骨移植，在对侧下颌骨行新鲜髂骨移植作对照。术后2周、4周各处死4只动物，制作标本进行扫描电镜、透射电镜观察。结果：实验组：术后2周主要表现为死骨，边缘有散在成骨细胞及点状钙盐沉积，透射电镜可见散在的代谢活跃的成骨细胞、幼稚骨细胞和破骨细胞。4周时植骨成骨活跃，新生骨占据大部分空间，切面上密布大量活跃成骨细胞、幼稚骨细胞及软骨细胞。对照组：2周时主要为死骨，边缘处只有非常少量的钙盐沉积，软骨细胞及成骨细胞活性差。4周时晶体沉积量显著增加但仍明显少于实验组，在皮质表面形成较厚的透明软骨，切面上可见很多中等活性的软骨细胞。结论：冷冻自体下颌骨复合髂骨移植术后早期有活跃的骨质再生，提示该手术方法用于下颌骨缺损整复是可行的。     

Early Healing of Hydroxyapatite‐Coated Implants in Grafted Bone of Zoledronic Acid–Treated Osteoporotic Rabbits

Background: Resorption of grafted bone and delayed osseointegration of implants are main problems associated with alveolar bone augmentation in dental implantology, especially for patients with osteoporosis. The aim of this study is to investigate the early healing response of implants to systemic treatment of zoledronic acid (ZA) in autogenous grafted iliac bone of osteoporotic rabbits. Methods: Ovariectomy (OVX) or sham operation was performed in 46 rabbits, and osteoporotic changes were verified in animals receiving OVX 3 months later. The remaining animals were divided into three groups (n = 12): sham, OVX, and OVX with ZA treatment (ZA group). Autogenous iliac bone grafting was performed in bilateral tibiae, and hydroxyapatite‐coated titanium implants were simultaneously placed into the grafted bone. The animals were sacrificed 2 and 8 weeks later for examination. Results: At both time points, systemic treatment of ZA efficiently promoted bone healing of implants in grafted bone, and all histologic and microcomputed tomography bone indices, including mineralized bone volume, implant–bone contact ratio, connectivity density, trabecular thickness, and trabecular number, were significantly increased in the ZA group compared with the OVX‐only group (P <0.01); implant–bone contact rates in the ZA group were even restored to levels similar to those of sham‐operated animals (P >0.05). Furthermore, biomechanical testing demonstrated that removal torque of implants was significantly increased in the ZA group compared with the OVX group (P <0.01). Conclusion: Systemic treatment with ZA could efficiently promote early bone healing of implants in autogenous grafted bone of osteoporotic rabbits by increasing early osseointegration and fixation of implants.     

Onlay bone grafts from iliac crest: a retrospective analysis

This study was performed to address the outcomes of patients treated with onlay grafts from the iliac crest to augment the deficient jaw. The results of 173 consecutive patients who underwent bone grafting prior to implant surgery are presented. The grafts were taken from the anterior iliac crest to repair alveolar bone deficiencies that were too large to be corrected using intraoral bone grafts. Three months postoperatively, 869 implants were placed into 190 onlay grafts (167 grafts in the maxilla, 23 in the mandible). The follow-up ranged from 3 months to 23 years post implantation. All patients received a fixed prosthesis. Parameters examined included healing of the donor site and bone grafts, implant survival, peri-implant condition, and donor site morbidity. The overall survival rate for all implants was calculated to be 95% ± 2.7% according to Kaplan–Meier analysis. The implant survival rate compares favourably with those reported in studies using intraoral and extraoral bone.     

Vertical ridge augmentation of the atrophic posterior mandible with interpositional bloc grafts: bone from the iliac crest vs. bovine anorganic bone. Clinical and histological results up to one year after loading from a randomized-controlled clinical trial

Objectives: To compare two different techniques for vertical bone augmentation of the posterior mandible: bone blocs from the iliac crest vs. anorganic bovine bone blocs used as inlays.
Materials and methods: Ten partially edentulous patients having 5–7 mm of residual crestal height above the mandibular canal had their posterior mandibles randomly allocated to both interventions. After 4 months implants were inserted, and after 4 months, provisional prostheses were placed. Definitive prostheses were delivered after 4 months. Histomorphometry of samples trephined at implant placement, prosthesis and implant failures, any complication after loading and peri-implant marginal bone-level changes were assessed by masked assessors. All patients were followed up to 1 year after loading.
Results: Four months after bone augmentation, there was statistically significant more residual graft (between 10% and 13%) in the Bio-Oss group. There were no statistically significant differences in failures and complications. Two implants could not be placed in one patient augmented with autogenous bone because the graft failed whereas one implant and its prosthesis of the Bio-Oss group failed after loading. After implant loading only one complication (peri-implantitis) occurred at one implant of the autogenous bone group. In 16 months (from implant placement to 1 year after loading), both groups lost statistically significant amounts of peri-implant marginal bone: 0.82 mm in the autogenous bone group and 0.59 mm in the Bio-Oss group; however, there were no statistically significant differences between the groups.
Conclusions: Both procedures achieved good results, but the use of bovine blocs was less invasive and may be preferable than harvesting bone from the iliac crest.     

Behavior of implants in bone grafts or free flaps after tumor resection

The authors compared bone resorption of autogenous bone grafts and revascularized free flaps used for the reconstruction of mandibular continuity defects following resection for tumors, before and after the placement of endosseous implants. Ten patients (group 1) were treated with autogenous bone grafts taken from the fibula or the anterior iliac crest; 8 patients (group 2) were treated with iliac or fibula revascularized flaps. Four to 8 months later, 72 endosseous implants were placed in the reconstructed areas. After a further healing period of 4-6 months, patients were rehabilitated with implant-borne prostheses. The following parameters were evaluated and compared between the two groups: 1) bone resorption of grafts and free flaps before and after implant placement; 2) peri-implant bone resorption mesial and distal to each implant, immediately after prosthetic rehabilitation and then during yearly follow-ups. Bone resorption before implant placement showed mean values of 3.53 mm in group 1, and 0.96 mm in group 2. Peri-implant bone resorption was: 0.49 mm (39 implants) in group 1, and 0.45 mm (30 implants) in group 2, at time of prosthetic rehabilitation; 0.78 mm (39 implants) in group 1, and 0.89 mm (30 implants) in group 2, 12 months after prosthetic load; 1.16 mm (24 implants) in group 1, and 1.02 mm (13 implants) in group 2, 24 months after the prosthetic load. A significant difference in bone resorption before implant placement was found between the two groups, whereas it was not found after implant placement and prosthetic load. The failure rate according to Albrektsson criteria was 4.9% (2/41 implants) in group 1, and was 3.2% (1/31) in group 2.     

The potential of the horizontal ramus of the mandible as a donor site for block and particular grafts in pre-implant surgery

The results on 32 consecutive patients, who underwent bone grafting prior to implant surgery, are presented. The grafts were taken from the horizontal part of the mandible, including the full height of the buccal cortico-cancellous plate and were used to reconstruct alveolar defects or to augment sinus floors. 3–5 months postoperatively, 99 implants were inserted in 43 onlay grafts and in 17 sinus floor augmentations. The follow-up ranged from 2–6 years post implant insertion. Parameters examined included: healing of donor site and bone grafts, implant survival, peri-implant condition, donor site morbidity and patient satisfaction. This study indicates that with one full height ramus graft, alveolar defects comprising a bicuspid–molar area, can be augmented. The grafted volume is also sufficient to augment one sinus floor. The implant survival rate (99%) compares well with studies using iliac crest or skull bone. Postoperative complaints were minimal, resulting in extremely high patient satisfaction (97%).     

冷冻自体牙-下颌骨复合组织块移植的实验研究

目的：研究冷冻自体下颌骨再植术时保留颌骨中牙根的可能性。方法;选用健康成年Ｗｉｓｔａｒ大白鼠４０只,任取２只用于观察下沉颌骨的组织学图像,其余的大鼠随机分为新鲜移植组和冷冻组,行牙－下颌骨复合组织块和我植到胫骨区的手术,分别于术后,１,２,３,４,６,８,１２,１６,２０周时处死动物,采用大观察,Ｘ线片,组织学及微血管造影等观察手段对牙－下颌骨复合组织块移植后的愈合过程进行比较。     

Three-dimensional finite-element analysis investigating the biomechanical effects of human mandibular reconstruction with autogenous bone grafts.

PURPOSE: To investigate the biomechanics of the mandible following reconstruction with autogenous bone grafts. MATERIAL: Computerized tomography scan images of a human mandible, fibula and iliac crest were collected and used to build models on a PC. METHODS: Four finite-element analysis (FEA) models of mandibles reconstructed with autogenous bone were created. The principal stresses of marked points, the Von Mises stresses at anatomical index regions, and the force values of temporo-mandibular joints and masticatory muscles were calculated. RESULTS: Compared with the normal mandible, the one repaired with a fibula had greater Von Mises stresses on the grafted bone; the one repaired with iliac crest bone had the similar distribution of the Von Mises stresses as in the normal mandible. The principal stresses in the autograft varied between tensile and compressive stresses from the right graft/bone binding interface to the left in all reconstructed mandibles. On the whole, the maximum Von Mises stress was greater on the mandible reconstructed with fibula than that reconstructed with iliac crest. CONCLUSION: Mandibles repaired with iliac crest grafts have more mechanical properties similar to normal than those repaired with fibula grafts.     

Implant placement and simultaneous ridge augmentation using autogenous bone and a micro titanium mesh: a prospective clinical study with 20 implants

This prospective clinical study evaluated bone regeneration around 20 dental implants placed in 15 patients (mean age 39.7 years). Peri-implant bone defects were augmented with autogenous bone grafts harvested intraorally from the mandible (chin or retromolar area). Augmented sites were covered with an individually trimmed micro titanium mesh which was rigidly affixed with microscrews to the residual jaw bone. Height of implant exposure (mean 6.5 mm), i.e. dehiscencies (80%) or fenestrations (20%), and graft height (mean 6.2 mm) were measured in an apico-coronal direction using a periodontal probe. At re-entry (mean interval 6.6 months) the titanium mesh and microscrews were removed and bone regeneration assessed. The mean height of the integrated bone graft was 5.8 mm corresponding to a mean bone fill of 93.5%. The overall postop healing course was excellent with only one site developing a soft tissue dehiscence with subsequent mesh exposure (complication rate 5%). This study demonstrated that a micro titanium mesh in combination with autogenous bone grafts is effective for treatment of peri-implant bone defects.