Augmentation of the rat jaw with autogeneic cortico-cancellous bone grafts and guided tissue regeneration

The aim of the present study was to evaluate the effect of augmenting the maxillary alveolar ridge and the lateral aspect of the mandible with onlay autogeneic cortico-cancellous bone grafts that were covered with e-PTFE membranes. The experiment was carried out in 51 rats. In 15 rats, the edentulous maxillary jaw between the incisor and the first molar was augmented by means of an autogeneic ischiac bone graft that was fixed with a gold-coated microimplant. In one side, the graft was covered with an e-PTFE membrane, while the other side, which served as control, was treated without a membrane. In the other 36 rats, the lateral aspect of the mandible was augmented in both sides by means of an autogeneic ischiac bone graft that was fixed with a gold-coated or a titanium microimplant. In one side, the augmented area was covered with an e-PTFE membrane, while the contralateral side was treated without a membrane. Histological analysis at 60, 120 and 180 days after augmentation of the maxilla showed that, in the case of the test sites (where most of the membranes were either exposed or lost), the bone grafts presented extensive resorption and there was a lack of bone continuity between the graft and the recipient site. Similar findings were made at the non-membrane-treated control sides. In the case of augmentation of the mandible with membranes, the bone grafts were not resorbed, but were integrated into newly formed bone at the recipient site. In the control sides, the grafts presented varying degrees of resorption and integration into the recipient bone. It is concluded that, in comparison to bone grafting alone, onlay ischiac bone grafting combined with guided tissue regeneration eliminates the risk of bone graft resorption and ensures integration of the graft into newly formed bone at the recipient site, provided that closure of the operated area can be maintained during healing.     

Prognostic factors for alveolar regeneration: bone formation at teeth and titanium implants

OBJECTIVES: There is a limited understanding of the effect of defect characteristics on alveolar bone healing. The objectives of this study were to assess the effect of alveolar bone width and space provision on bone regeneration at teeth and titanium implants, and to test the hypothesis that the regenerative potentials at teeth and implants are not significantly different. METHODS: Critical size, 5-6-mm, supra-alveolar, periodontal defects were surgically created in 10 young adult dogs. Similarly, critical size, 5-mm, supra-alveolar, peri-implant defects were created in four dogs. A space-providing expanded polytetrafluoroethylene device was implanted for guided tissue regeneration/guided bone regeneration. The animals were euthanized at 8 weeks postsurgery. Histometric analysis assessed alveolar bone regeneration (height) relative to space provision by the device and the width of the alveolar crest at the base of the defect. Statistical analysis used the linear mixed models. RESULTS: A significant correlation was found between bone width and wound area (r=0.55892, p<0.0001). Generally, bone width and wound area had statistically significant effects on the extent of bone regeneration (p<0.0005 and p<0.0001, respectively). Bone regeneration was linearly correlated with the bone width at periodontal (p<0.001) and implant (p=0.04) sites, and with the wound area at periodontal (p<0.0001) and implant (p=0.03) sites. The relationships of bone regeneration with these two variables were not significantly different between teeth and implants (bone width: p=0.83; wound area: p=0.09). When adjusted for wound area, bone regeneration was significantly greater at periodontal than at implant sites (p=0.047). CONCLUSIONS: The horizontal dimension of the alveolar bone influences space provision. Space provision and horizontal dimension of the alveolar bone appear to be important determinants of bone regeneration at teeth and implants. The extent of alveolar bone formation at implant sites is limited compared with that at periodontal sites.     

大龄腭裂患者同期腭裂修复与齿槽嵴裂植骨的临床观察

目的：探讨８岁以上单侧完全性腭裂患者同期腭裂修复与齿槽嵴裂植骨的可行性及植骨效果。方法：对３８例同期腭裂修复与齿槽嵴裂植骨的腭裂患者作回顾性研究。患者年龄８～２４岁,平均年龄为１４．８岁。分析手术时间、术中出血、术后恢复和创口愈合情况。术后随访１２月以上,对随访的Ｘ线片进行植骨效果的客观评价。结果：所有手术均顺利完成,平均手术时间比单纯改良兰氏腭裂修复手术多３７ｍｉｎ,没有明显增加术中出血量,患者     

髂骨块状骨植骨术修复恒牙列牙槽突裂的短期临床观察

目的探讨牙槽突裂髂骨块状骨植骨术的临床可行性和可靠性。方法回顾分析15例行"牙槽突裂髂骨块状骨植骨术"的恒牙列牙槽突裂患者,随访6个月以上,收集临床资料,并进行影像学分析。结果所有患者均能定期复诊,术后13例患者创口愈合良好,2例因创口裂开导致植骨失败。影像学资料显示术后6个月植骨区间隙消失,骨桥形成,且植骨区无明显吸收。已有2例患者完成正畸及种植治疗。术后3个月所有患者均可正常行走,无明显行动障碍。结论牙槽突裂髂骨块状骨植骨术短期临床效果满意,移植骨吸收少,长期效果还需进一步研究。     

Mid Versus Late Secondary Alveolar Cleft Grafting Using Iliac Crest Corticocancellous Bone Graft

Background

Mid-secondary alveolar cleft repair performed at ages 9–12, in the mixed dentition stage, prior to eruption of the permanent canine, is generally accepted as the ideal time for residual alveolar cleft closure in cleft lip and palate cases with a cleft alveolus.

Methods

In our study, four cases of mid-secondary and five cases of late–secondary alveolar cleft grafting were carried out using iliac crest corticocancellous bone graft. Clinical defect closure and radiographic bone fill were compared.

Results

All the nine cases performed in the two different age groups showed excellent results, clinically, with complete closure of the cleft defect and achievement of continuity of the dental arches. One case was planned for a two-stage procedure owing to the large bilateral maxillary defects. Good bone fill was visualized radiographically in all nine cases.

Conclusion

Precise timing for undertaking alveolar cleft repair may not be all that crucial for a successful alveolar cleft grafting procedure.     

Alveolar ridge augmentation using a resorbable copolymer membrane and autogenous bone grafts. An experimental study in the rat

The aim of the present study was to compare the result of maxillary alveolar ridge augmentation by the combined use of mandibular bone grafts and resorbable membranes (Resolut), with that achieved by the use of the same type of bone graft combined with the placement of e-PTFE membranes (Gore-Tex). The experiment was carried out in 30 rats. In one side of the maxillary jaw, the edentulous alveolar ridge between the incisor and the first molar was augmented by means of an autogenous mandibular bone graft that was fixed with a titanium microimplant and covered with a resorbable membrane. The contralateral side, serving as control, was treated in the same way, with the difference that an e-PTFE membrane was placed over the bone graft. Histological analysis at 15, 30, 60, 120 and 180 days after surgery demonstrated that, in both test and control sites where the membrane was properly adapted and not exposed, the bone grafts presented no resorption and were integrated into the maxillary bone at the recipient site. In cases where the membrane was exposed, however, the bone grafts presented extensive resorption and lack of continuity between the graft and the recipient bed. At 60-180 days after surgery, the exposure of both types of membrane had frequently led to complete resorption of the grafts, encapsulation of the titanium microimplant by fibrous connective tissue, or exfoliation of the microimplant. It is concluded that alveolar ridge augmentation can be predictably accomplished by combining mandibular bone grafting with the placement of resorbable or non-resorbable membranes according to the GTR principle, provided that the membrane is properly adapted over the graft and complete closure of the treated area is maintained during healing.     

牙槽突裂的裂隙特点及正畸治疗对唇腭裂患者牙槽突植骨术的影响

牙槽突裂是位于唇腭裂患者上颌牙弓处的骨缺损,常发生于侧切牙与尖牙之间。由于先天性裂隙、早期手术治疗所致瘢痕挛缩及唇肌压迫等原因,患者多并发严重的上颌骨横向发育障碍。牙槽突植骨术作为唇腭裂序列治疗中的重要步骤,是修补上颌骨裂隙和矫正上颌横向发育不足的有效手段。众多临床实践及研究发现,正畸治疗的时机选择与牙槽突植骨术的成功率及预后效果密不可分,同时,牙槽突裂的裂隙特点对牙槽突植骨术产生的影响也不可忽视。本文就牙槽突裂的裂隙特点与正畸治疗时机对牙槽突植骨术成功率及预后的影响两方面进行综述,以期为唇腭裂患者临床治疗方案的选择及实验研究的设计提供一定的依据。     

自体松质骨支持引导组织再生膜重建牙槽嵴的初步临床研究

目的:观察自体松质骨结合引导组织再生膜技术重建牙槽嵴的临床效果。方法:小切口微创取自体髂骨松质骨粒移植于牙槽嵴表面,上方覆盖聚四氟乙烯引导膜,为6例患者修复萎缩或缺损的牙槽嵴,分别在术前,术后1周,12周进行临床检查、测量重建高度或宽度,作X线检查,并对1例患者12周时的再生骨行组织学检查,观察临床重建效果。结果:牙槽嵴形态以及骨量较手术前得到明显改善,12周时6例牙槽嵴平均增宽,增高4.20 mm,X线检查表明术后植骨区骨组织量增多、骨密度较术前更致密;术后12周植骨部位组织学表现为排列不规则的板层新生骨,可见大量的成骨细胞突起。结论:自体松质骨移植与膜引导组织骨再生技术联合增高牙槽嵴取得满意疗效,值得推广应用。     

Prognostic factors for alveolar regeneration: effect of a space-providing biomaterial on guided tissue regeneration

OBJECTIVES: There is a limited understanding of the effect of bone biomaterials on the healing potential when used in conjunction with guided tissue regeneration (GTR). The objective of this study was to evaluate the effect of a space-providing coral-derived biomaterial on alveolar bone regeneration in conjunction with GTR. METHODS: Bilateral, critical-size, 6-mm, supra-alveolar, periodontal defects were created in four young adult Beagle dogs. In a split-mouth design, the animals received an ePTFE device to provide for GTR in contralateral defect sites with or without the coral biomaterial. The animals were euthanized at 4 weeks post surgery. A histometric analysis assessed vertical regeneration of alveolar bone relative to space-provision by the ePTFE device. Because of the correlation of within-dog measurements, a mixed model ANOVA was used to analyze the data. RESULTS: There was significantly greater mean bone regeneration in sites receiving calcium carbonate coral implant GTR (cGTR) compared to GTR (p < 0.0001). Sites providing larger wound areas exhibited greater bone regeneration compared to sites exhibiting smaller wound areas (p < 0.0001). However, grouping the sites by wound area thresholds showed that bone regeneration was not significantly different in sites receiving cGTR compared to sites receiving GTR alone, irrespective of the size of the wound area (p > 0.5). Conclusions: Space-provision has a significant effect on bone regeneration following GTR. The coral biomaterial effectively enhances space-provision, and this appears to be the principal mechanism by which this biomaterial supports bone regeneration rather than postulated osteoconductive properties.     

牙槽突裂骨移植治疗进展

牙槽突裂骨移植是口腔颌面部裂隙畸形重建的重要步骤。初期肋骨移植能使上颌骨连续,消除口鼻腔瘘,不影响面中部发育,有助于防止双侧唇裂上颌骨节段性塌陷。二期髂骨移植成功率高,能稳定地产生小梁骨,恢复上颌骨连续性,提供正畸支持。牙槽突植骨能否产生足够的牙槽骨支持后期的正畸治疗,尚需进一步研究。本文就牙槽突裂骨移植治疗的进展作一综述。