锥形线束CT在牙槽外科手术中的应用价值

目的 :探讨锥型线束CT在牙槽外科手术中的应用价值。方法 :对 3 1例需拔牙或行种植义齿病例行锥型线束CT检查 ,扫描层厚 0 .62 5mm或 1.2 5mm ,扫描数据输入重建工作站 ,依据需要进行图像重建 (包括曲面重建、矢状位重建、冠状位重建等 ) ,重建层厚均为 0 .62 5mm。对图像进行分析及测量 (包括骨质厚度、高度等 )。结果 :锥型线束CT可清楚显示牙根与下牙槽神经管及上颌窦之间的解剖关系。能精确测量出上、下颌骨的厚度、高度及任何解剖标志之间的距离。结论 :锥形线束CT ,可精确定位 ,能清晰地描述颌骨的解剖结构及对某些数据进行精确测量 ,对指导牙槽外科的手术设计 ,预防手术并发症 ,具有重要的临床应用价值。     

Relationships between implant stability, image-based measures and nitric oxide levels

For monitoring of dental implants, practitioners seem to use simultaneously a variety of image-based and laboratory measurements. This longitudinal study was conducted to analyse the possible relationships between nitric oxide (NO) content of peri-implant sulcus fluid (PISF), marginal bone levels and implant stability in terms of resonance frequency analysis (RFA) at immediately (IL) and conventionally (CL) loaded mandibular molar dental implants from the same individuals. Dental implants were placed in 10 patients who had first molar loss bilaterally in the mandibular area. One site of the patient was determined as IL and the other site was CL. PISF samples, marginal bone level and RFA were taken for all dental implants during a 12-month follow-up period. For both types of loading, there were no significant changes at implant stability (ISQ) and PISF volume during the whole study period. The lowest total nitrite levels were observed at the end of 12 months. Marginal bone gain of 0.22 and 0.09 mm was noticed between 6 and 12 months in IL and CL groups, respectively. During the study period, negative correlation was noted between radiographic bone level and ISQ at both IL and CL sites; however, this correlation reached a significant level only at 6 months in CL implant group (P = 0.015). Although not significant, marginal bone loss seems to have a negative relationship with the implant stability values regardless of the mode of loading. NO metabolism around IL and CL dental implants may not demonstrate a significantly different pattern.     

A case of Burkitt's lymphoma that presented initially with resorption of alveolar bone

A 16-year-old male was evaluated for a 1-month history of alveolar bone resorption, which had been treated with endodontics by a neighborhood dentist. Intraoral examination showed slight gingival swelling and teeth mobility. However, no tumor mass was seen. The panoramic image showed resorption of alveolar bone and loss of teeth lamina dura. Because he complained of general fatigue, he was introduced to the internist. Biopsies of gingiva and bone marrow aspiration revealed a massive proliferation of lymphoblasts expressing CD10, 19, 20 and HLA-DR antigens on the surface. Their karyotypes were abnormal; 46, XY, t (8;14) (q24;q32). Accordingly, he was diagnosed as Burkitt's lymphoma, and received intensive chemotherapy which relieved his symptoms and decreased his tumor. However, his disease soon became refractory to chemotherapy, and he died 11 weeks after the onset.     

Nitric oxide promotes the progression of periapical lesion via inducing macrophage and osteoblast apoptosis

This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts.     

牙槽突植骨同期髂软骨移植治疗单侧唇腭裂术后鼻畸形

目的:介绍牙槽突植骨同期髂软骨移植治疗单侧唇腭裂术后鼻畸形的方法。方法:2003年3月～2004年3月,12例单侧唇腭裂术后严重鼻畸形患者在牙槽突植骨术的同时行鼻成形术,并切取部分髂软骨雕刻成"L"形,作为隆鼻支架移植于鼻背和鼻小柱处。所有患者术前、术后测量了鼻尖突度、鼻小柱高度、鼻孔横径、鼻孔纵径、鼻小柱偏斜度和鼻唇角,并拍摄面部照片。应用配对 t 检验对数据进行了比较。结果:术后患者鼻孔对称,鼻尖挺拔,鼻外形有了明显改观,术后鼻外形各项数值较术前有显著性差异(P<0.01)。结论:髂软骨移植可为患侧鼻翼软骨提供额外的支持,可用以治疗唇腭裂术后鼻畸形。     

Clinical application of a new compact CT system to assess 3-D images for the preoperative treatment planning of implants in the posterior mandible A case report

When treatment planning before placing dental implants in the posterior region of the mandible, the locations of the inferior alveolar nerve and mental foramen need to be ascertained, as they determine the bone height available and the implant length selected. The purpose of this study was to introduce the clinical application of a newly developed compact computed tomography system (Ortho-CT) to assess three-dimensional (3-D) images for the preoperative treatment planning of implants in the posterior region of the mandible. To evaluate the 3-D images, we scanned using the Ortho-CT system the mandible with a radiopaque template placed in the posterior region. The Ortho-CT images provided excellent information for evaluating the morphology of the mandible, and for showing the location of the inferior alveolar nerve, mental foramen and the relationship of the template to the bone. We consider that Ortho-CT is a useful aid to preoperative treatment planning of implant therapy in the mandible.     

外斜线取骨自体骨移植及其他牙槽嵴骨增量法的研究进展

针对严重骨缺损且有种植修复意向的牙列缺损位点，自体骨移植是实现种植体三维方向充足骨量的“经典方案”，常用的口内供骨区有颏部和外斜线区域。相比颏部取骨，下颌骨外斜线取骨移植后神经并发症少，但跟其他牙槽嵴骨增量方式相比，术后骨吸收率大。本文重点讲述下颌骨外斜线块状取骨及其局限性，并阐述了其他临床应用广泛的牙槽骨增量方法，对比移植骨术后牙槽嵴宽度及高度变化、术后骨吸收率，为临床提供减小外斜线块状取骨局限性的其他骨增量方法。     

口腔内局部因素对于牙槽骨吸收的影响

牙槽骨是高度可塑性组织，人体骨骼中代谢最活跃的部分。牙槽骨具有受压力侧吸收，受牵引力会增生的特性，改建符合Wolff定律。牙槽骨是全身骨骼的一部分．影响骨代谢的全身因素如维生素D缺乏、中年妇女雌激素水平下降、与骨代谢有密切关系的神经肽（如神经肽Y、β-内啡肽，一氧化氮等）、还有影响钙磷代谢的一些疾病均会对牙槽骨产生一定影响。     

软衬材料用于下颌慢性牙槽嵴疼痛的临床评价

目的：评价软衬材料用于治疗下颌慢性牙槽嵴疼痛的效果。方法：对16例下颌慢性牙槽嵴疼痛的患者,采用Molloplast-B软衬材料衬垫下颌全口义齿,于修复后1个月行舒适度问卷调查,采用秩和检验进行统计学分析,于使用软衬前后进行咀嚼效能测定。结果：16例患者的疼痛症状均有缓解,7例患者的固位有改善,14例咀嚼效果有改善;使用软衬后咀嚼效能显著提高。结论：短期内Molloplast-B软衬材料对下颌慢性牙槽嵴疼痛,有良好的临床效果。