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种植全口覆盖义齿是依靠种植体基台、牙槽嵴和黏膜共同支持的全口覆盖义齿,并以其具有良好的固位、支持和稳定而越来越多地应用于临床。有限元分析法作为一种应用在多个领域的理论力学分析方法,从20世纪70年代开始应用于口腔种植学领域,使种植义齿生物力学的研究进入了一个新阶段。本文就有限元分析法在种植全口覆盖义齿研究中的应用现状及进展做一综述。     

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是上下颌牙列之间的静态接触或动态咬合接触关系,以及在口颌系统功能和功能紊乱中控制牙接触的系统各组成成分之间的一种动态的生物学关系。学以咬合研究为中心,探索咬合的生理病理特性及临床应用,理解咬合形态与功能的辩证关系。与颌位是学研究的基本概念,对牙尖交错位、后退接触位、下颌姿势位及正中关系的正确理解在临床工作有重要意义。     

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??Amelogenesis imperfecta is an isolated inherited disorder that is associated with mutations in more than 10 genes. It has a wide range of clinical presentations and genetic etiology?? affecting the development of enamel?? both in the primary and permanent dentition. Early diagnosis is critical for treatment planning and prognosis evaluation.     

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??Prolonged loss of unilateral posterior teeth will not only influence chewing habits??but also cause secondary occlusal disorders. Past researches have proved that posterior teeth loss is related to morphological reconstruction of temporomandibular joint. As the main area bearing occlusal force??condyle is the most active part in reconstruction. This article reviewed the current researches on the effects of unilateral posterior teeth loss on morphology of condyle.     

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提要：根管治疗术后根尖发生微渗漏是导致根管治疗失败常见的原因之一。根管治疗术后根尖微渗漏的影响因素有很多, 包括根管预备及充填方法、玷污层的处理、根充材料等。本文对此做一综述。     

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树突状细胞(dendritic cells,DC)代表了血液循环中抗原呈递细胞的一个大家族,分布于机体几乎所有组织。DC在人类血液单核细胞中仅占0.1～1.0,皮肤中占0.4,牙龈中占0.1～2.0。由于它们在体内稀少,缺少由DC家族所有成员表达的细胞标志物,因此在构成先天性免疫     

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??At present??the attention to removable partial denture??RPD??for dentition defect is getting lower and lower. However??in clinical practice??RPD is still a widely used repair method for dentition defects because of limitations in patients' physiological conditions??oral anatomy conditions??and economic conditions. The article focuses on the RPD production materials??the design of RPD??the influence of RPD on oral environment??and the application of digital technology in RPD.     

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??Toluidine blue ??TB????an alkaline thiazide cationic dye??which can be combined with the acidic substances in the tissue cells??is an important dye for nucleic acid staining. Because of the specific binding of TB to nucleic acids??TB can be retained in cancer tissue preferentially and widely used in the diagnosis of malignant tumors of the mouth??the eye??and the upper digestive tract. TB plays an important role in medical research. In addition??as an effective photosensitizer??TB can be widely used in photodynamic antimicrobial and antitumor therapy. The purpose of this review is to provide a summary about the research situation and the application of TB in oral medicine.     

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X线头影测量技术于1931年由Broadbent和Hofrath分别提出,是在X线头颅定位侧位片上描图,确定一些标志点.     

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疼痛是严重困扰人类健康的疾病。迄今为止,关于疼痛的产生机制尚不完全明确。谷氨酸是脑内最重要的兴奋性递质之一,是初级痛觉传入的主要神经递质。它能够与谷氨酸受体相结合,从而产生生物学效应。本文参考国内外文献综述了代谢型谷氨酸受体5参与疼痛的研究现状。     

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咬合板治疗口颌系统的功能紊乱已有100余年历史,并且至今仍在广泛使用.虽然各种假说一直用来解释其作用,但科学证据不多.普遍认为,咬合板具有保护牙齿不被磨耗的作用,但咬合板在颞下颌关节紊乱痛(TMD)处理中的功效始终很难确定.尽管许多研究认为咬合板减少了夜磨牙发生的频率,但并不表明这会消除磨牙症.戴用咬合板会使咀嚼肌和关节疼痛减少,但也可能是安慰剂效应和症状随时间而自然回归的结果.最新的系统回顾和Meta分析显示,合理调改硬质稳定咬合板对治疗TMD疼痛有效,有证据表明其他类型的咬合板包括软质稳定咬合板、再定位咬合板、松弛咬合板也有一些减少TMD疼痛的功效,但其潜在的副效应也存在,建议在密切监测下使用.本文对目前临床上使用的咬合板的种类及其作用机制进行了评述,重点对咬合板特别是稳定咬合板的作用、治疗价值、应用和注意事项等进行了介绍.强调合理选用和调改咬合板是治疗口颌系统功能紊乱能否成功的关键因素.     

[牙合]垫对牙齿重度磨耗患者口颌功能影响的临床研究

目的：研究殆垫对牙齿重度磨耗患者口颌功能的影响。方法：用殆垫恢复10例牙齿重度磨耗患者的垂直距离,分别检测治疗前、治疗后1个月、3个月、6个月的咬合平衡性、咬肌及颞肌前束的肌电幅值、颌位及殆的稳定性以及边缘运动的平滑度及对称性的变化。结果：①咬合平衡性、颌位及胎的稳定性以及边缘运动轨迹的平滑度及对称性在治疗后呈逐渐改善趋势,治疗6个月后80％的患者恢复正常;②治疗后各组的息止位肌电幅值均较治疗前显著降低（P〈0．05）,正中颌位紧咬时肌电幅值在治疗后3个月组和6个月组较治疗前显著增加（P〈O．05）。结论：通过6个月的治疗和观察,聆垫对重度磨耗患者的口颌功能的影响呈现持续改善趋势。     

[牙合]平面的研究进展

平面是影响口颌系统功能的重要因素之一。对患者进行口颌功能修复或重建时,确定适宜的平面是重要的一步。本文结合国内外学者的研究状况,对平面的定位及其影响因素、平面与口颌系统的关系以及平面与颈椎的关系等进行综述。     

咬合创伤致咀嚼肌疼痛的中枢机制研究

目的观察咬合创伤后咬肌区的化学和机械伤害性刺激对中枢神经系统c- fos、P物质（ SP）表达的影响。方法在!面洞型内放入一个2 mm牙用固位钉造成咬合干扰,咬合创伤形成后7 d,咬合创伤机械刺激组和机械刺激对照组在麻醉下对左侧咬肌区行机械性刺激,记录有疼痛反应次数,2 h后处死动物。咬合创伤化学刺激组和化学刺激对照组在麻醉下左侧咬肌区注射体积分数为5%甲醛,2 h后处死动物。取大鼠脑干组织,用SABC漂染法检测c- fos、SP表达,并定量分析。结果机械刺激和化学刺激后,c- fos在脑干obex水平和颈髓C1- 2水平有两个表达高峰,咬合创伤机械刺激组和咬合创伤化学刺激组动物c- fos表达均明显高于其对照组（ P<0.05）。咬合创伤机械刺激组机械性刺激后脑干SP表达明显高于其对照组（ P<0.05）,在颈髓C1- 2水平SP表达咬合创伤机械刺激组比其对照组增高,但无统计学差异（ P=0.072）。结论咬合创伤可引起脑干和颈髓中枢神经元的敏化,是咬合创伤致咀嚼肌疼痛的中枢机制之一。     

脑功能性磁共振成像在口颌系统领域的应用

脑功能性磁共振成像是一种非常有效的研究脑功能的非介入技术,它以血氧合度依赖的对比为基本成像原理,能准确定位、实时跟踪神经活动引起的脑血流和代谢改变.将其用于研究口颌系统,可明确中枢神经系统与颌面肌、(牙合)及颞下颌关节间的调控关系,为填补该领域的空白提供了一种良好的研究手段.     

Influence of wearing a scuba diving mouthpiece on the stomatognathic system – considerations for mouthpiece design

Although diver's mouth syndrome (DMS) has long been recognized by scuba divers, little attention has been paid to the influence of wearing a scuba diving mouthpiece on the stomatognathic system. In this review, DMS‐related stomatognathic events (DMS‐SE) while wearing a mouthpiece, the relationship between components of the mouthpiece and those events, and design considerations to reduce the risk of those events are discussed based on evidence from 32 articles concerning scuba diving mouthpieces. Forward movement of the mandible, loss of molar occlusal support, and continuous jaw clenching while wearing a mouthpiece are considered to be pathogenic for DMS‐SE. Several experimental studies have suggested a relationship between incidence of those events and the design of mouthpiece components such as the connector, labial flange, platform, and occlusal rug, and the possibility of reducing risk of those events through design customization of these components. Improvement of the shape of commercially available mouthpieces and creation of custom‐made mouthpieces may thus contribute to the prevention and treatment of DMS‐SE and the provision of a comfortable diving environment.     

Masticatory jaw movement optimization after introduction of occlusal interference

Summary How ‘control’ characteristics of masticatory jaw movement, such as skilfulness of the movement, change after alteration in occlusion remains uncertain. For each of 10 healthy adults with good occlusion, an occlusal interference with artificial ‘tooth‐cusp’ was introduced to the crown of the upper molar tooth on the non‐working side of unilateral chewing. Mandibular incisor‐point movements were then recorded by a 3D tracking device. The introduction of the occlusal interference induced a remarkable increase in the normalized jerk‐cost (NJC), prolonged duration of the decelerative phase and lowered peak velocity for jaw closing movement during chewing. Overall, the NJC and velocity profile showed significant recoveries during the course of about 90 repetitive chewing cycles performed under the altered occlusal condition. These findings suggest that acute adaptive changes of jaw motion after introduction of occlusal interference might be characterized as the recovery process of movement skilfulness in terms of movement smoothness and velocity profile.     

TMD患者咬合板治疗后接触变化的研究

目的:比较咬合板治疗颞下颌关节紊乱病(TMD)前后异常因素的变化情况,探讨咬合板治疗TMD的机理。方法:选取34名用咬合板治疗的TMD患者,记录其戴用咬合板后2个月时的咬合特征及临床症状,并与治疗前进行比较。结果:TMD患者治疗后的力中心距中线距离减小,闭合时间与侧方分离时间明显较治疗前缩短,早接触出现率较治疗前降低,但前伸分离时间、非工作侧干扰及前伸干扰的出现率与治疗前相比无显著性差异。结论:咬合板对于纠正力中心位置、减小早接触的发生率、缩短闭合时间及侧方分离时间具有明显的作用,能够使TMD患者的关系向着更加协调、稳定的方向发展,是其有效治疗TMD的重要机理。     

The effect of experimental occlusal interferences on nerve growth factor levels in periodontal tissues

Objective

To test the hypothesis that experimental occlusal interferences increase the nerve growth factor (NGF) levels in periodontal tissues and cause an up-regulation of preprotachykinin-A (PPTA) mRNA.

Background

NGF is related to hyperalgesia and inflammation. PPTA mRNA, a primer of substance P, is a possible factor in the aetiology of pain.

Methods

Experimental interferences were created by placing inlays in the right maxillary molars of 15 dogs. The right side molars formed the experimental group. The left side molars served as controls. Three dogs with cavities prepared without changing the occlusion formed a sham group. The dogs in the first group were sacrificed, 3 at each time, after 3, 7, 14, 30, and 60 days. The sham group was sacrificed after 14 days. The levels of NGF in periodontal tissues and PPTA mRNA in the trigeminal ganglions were detected by ELISA and TR-PCR. Comparisons were made with paired t-tests and a multivariate MANOVA test.

Results

On all measurement days, there were higher levels of NGF mRNA, PPTA mRNA, and NGF on the experimental than on the control side in 14 of 15 comparisons and in the sham group. NGF production in periodontium was time-dependent. No differences in NGF protein levels were observed between the control and the sham groups.

Conclusion

The results which need confirmation in further tests are of clinical interest. They indicate that occlusal experimental interferences may be an etiologic factor in oral facial pain by increasing mRNA and NGF protein levels in the periodontal tissues.