Sneha Gada^*; Sathvik Nallluri, Thiyaneswaran Nessapan, Deepak Nallaswamy

Prosthodontics, Saveetha Dental College, Chennai, India

Background: Vertical ridge augmentation is one of the greatest challenges in the field of bone regeneration for implants. Several techniques have been proposed for vertical ridge augmentation, namely block grafts (onlay, inlay grafts), distraction osteogenesis and guided bone regeneration. There have been continual efforts to develop newer techniques like tenting, sandwich technique, tunneling technique etc. However, the evidence to support the various techniques of augmentation has been insufficient.

Aim/Hypothesis: The aim of this study is to perform a randomized controlled trial to assess the bone volume gain by the split buccal bone (SBB) and cortical tenting technique (CT) in the posterior mandibular region in a split mouth situation.

Material and Methods: Nine partially edentulous patients (mean age 53.78years, range 40-70), requiring bilaterally vertical augmentation for future implant placement, had their posterior mandibles randomly allocated to both the interventions (SBB or CT). A bone block, harvested from the lateral aspect of the mandibular ramus, was bisected into two cortical laminae. These laminae were used to reconstruct the buccal and palatal walls of an alveolar ridge defect in the SBB technique and as an onlay tent in the CT technique. The inter-laminar space was filled with particulate autogenous bone and the whole graft was covered with a double-layered Creos Xenoprotect collagen membrane. Cone bean computed tomography (CBCT) measurements were made in the diagnostic phase, after 3 and 6 months using a splint with radio-opaque markers. After a mean interval of 6.4 months, the surgical site was re-entered, the screws were removed and the site was prepared to receive endosseous implants.

Results: Nine patients with 18 grafted sites were treated. In the SBB group, the mean pre-operative bone heights measured (above the inferior alveolar canal) was 6.88 ± 1.41 mm and the mean horizontal width was 3.75 ± 0.96 mm. Postoperatively, the mean vertical dimension gained was 5.78 ± 1.63 mm (maximum: 6.9 mm), and the mean width gain was 4.87 ± 1.10 mm (p < 0.001). In the CT group, the mean pre-operative bone heights measured was 6.43 ± 1.34 mm and the mean horizontal width was 4.01 ± 0.45 mm. Postoperatively, the mean vertical gained dimension was 5.05 ± 1.04 mm (maximum: 6.7 mm), and the mean width gain was 4.59 ± 0.81 mm (p < 0.001). The difference observed was statistically significant (p ≈ 0.018). Soft tissue dehiscence was seen in three patients in the CT group, and two patients in the SBB group. There was an average resorption of 6.3% seen, except for one case, where there was a 36% graft resorption due to intra-operative complications. All the surgical sites, except for one, received implants.

Conclusion and Clinical implications: Split buccal bone augmentation showed higher bone gain values compared to the cortical tenting. The results of this study implied that block grafts in combination with particulate autogenous grafts are predictable treatment options for ridge reconstruction. The use of thin cortical laminae with particulate graft create an osteoinductive scaffold for bone regeneration, help in neovascularization in comparison to thick block grafts as well as show higher resistance to resorption.

Disclosure of Interest: None Declared

Keywords: bone graft, clinical studies/trials, guided bone regeneration

斯内哈·加达^* ; 萨斯维克·纳尔鲁里、蒂亚内斯瓦兰·内萨潘、迪帕克·纳拉斯瓦米

修复学，Saveetha 牙科学院，印度钦奈

背景：垂直嵴增强是种植体骨再生领域的最大挑战之一。已经提出了几种用于垂直脊增强的技术，即块状移植物（高嵌体、嵌体移植物）、牵张成骨和引导骨再生。一直在不断努力开发新技术，如帐篷、三明治技术、隧道技术等。然而，支持各种增强技术的证据不足。

目的/假设：本研究的目的是进行一项随机对照试验，以评估在张开嘴的情况下，在后下颌骨区域中，颊骨裂开 (SBB) 和皮质帐篷技术 (CT) 的骨量增加。

材料与方法：9 名部分缺牙患者（平均年龄 53.78 岁，范围 40-70），需要双侧垂直增强以供未来种植体植入，他们的后下颌骨随机分配到两种干预措施（SBB 或 CT）。从下颌支的侧面采集的骨块被分成两个皮质层。这些薄层用于在 SBB 技术中重建牙槽嵴缺损的颊壁和腭壁，在 CT 技术中用作覆盖帐篷。层间空间充满颗粒状自体骨，整个移植物覆盖有双层 Creos Xenoprotect 胶原膜。锥豆计算机断层扫描 (CBCT) 测量在诊断阶段进行，在 3 个月和 6 个月后使用带有不透射线标记的夹板进行。在平均间隔 6.4 个月后，

结果： 9 例患者共 18 个移植部位接受治疗。在 SBB 组中，术前测量的平均骨高度（下牙槽管上方）为 6.88 ± 1.41 mm，平均水平宽度为 3.75 ± 0.96 mm。术后，平均垂直尺寸增加为 5.78 ± 1.63 毫米（最大值：6.9 毫米），平均宽度增加为 4.87 ± 1.10 毫米（p < 0.001）。在 CT 组中，术前测量的平均骨高度为 6.43 ± 1.34 mm，平均水平宽度为 4.01 ± 0.45 mm。术后，平均垂直增益尺寸为 5.05 ± 1.04 毫米（最大值：6.7 毫米），平均宽度增益为 4.59 ± 0.81 毫米（p < 0.001）。观察到的差异具有统计学意义（p≈ 0.018）。CT 组 3 名患者和 SBB 组 2 名患者出现软组织裂开。观察到平均吸收率为 6.3%，除了一个病例外，由于术中并发症，移植物吸收率为 36%。除一处外，所有手术部位都植入了植入物。

结论和临床意义：与皮质帐篷相比，分裂颊骨增强显示出更高的骨增量值。这项研究的结果表明，块状移植物与颗粒状自体移植物相结合是牙槽嵴重建的可预测治疗选择。使用带有颗粒移植物的薄皮质层为骨再生创造了骨诱导支架，与厚块移植物相比有助于新血管形成，并显示出更高的再吸收抵抗力。

利益披露：无申报

关键词：骨移植，临床研究/试验，引导骨再生