颈外动脉危险吻合血管造影研究

目的：研究颈外动脉与颈内动脉，椎动脉间存在的危险吻合，方法：分析了250例颈外动脉造影图像中存在的危险吻合现象（包括烟雾病35例，头颈部高血运病变216例，其中7例已行戏外动脉结扎）。结果：烟雾病中14侧病脑中动脉，11例颞浅动脉，7例枕动脉参与颅内供血；颈外动脉结扎病例均丰在咽枕吻合，此外，还发现3例（3／250）眼动脉由脑膜中动脉异常起源，结论：颈外动脉与颈内动脉，椎动脉间存在多种危险吻合途径，栓塞治疗时应高度注意并予以适当处理，以避免造成颅内误栓。     

Influence of conventional forceps extraction and extraction with an extrusion instrument on cementoblast loss and external root resorption of replanted monkey incisors

Cementoblast loss and root resorption on the root surface was registered histologically after removal and immediate replantation of maxillary central incisors in monkeys ( Cecropithecus aethiops ). Incisors were removed with either a conventional extraction technique using forceps or with a special designed extrusion instrument and in both cases teeth were immediately replanted. Altogether 18 monkeys were used for the experiments in which 9 monkeys were sacrificed after 3 d and 9 animals after 8 wk. Histological analysis was made in horizontal sections perpendicular to the long axis of the tooth using either 24 measuring points or 12 sections. Histometric analysis showed extensive cementoblast loss in the periodontal ligament (PDL) and with a maximum of damage occurring on the corner surfaces of the root. Extracted teeth showed significantly more extensive cementoblast loss than extruded teeth. Root resorption was also found in the corner locations and was significantly more frequent in extracted than in extruded teeth. There was a similarity in the distribution of cementoblast loss and root resorption indicating that root resorption develops in the same areas where cementoblast loss takes place, i.e. locations that are more compressed during removal of the tooth and must have caused by mechanical damage to the PDL exerted on the root surface during tooth removal.     

埋伏阻生牙导致牙根外吸收邻牙的预后的临床观察

目的 探讨埋伏阻生牙导致邻牙（恒牙）牙根外吸收（ERR）时,阻生牙拔除术后邻牙的预后。方法 以埋伏阻生牙导致邻牙（恒牙）ERR但可以正常行使功能的63例患者的75颗ERR邻牙作为研究对象,微创拔除埋伏阻生牙后,术后随访6月,观察ERR邻牙的预后情况,并分析预后与患者年龄、性别、牙根数量、牙根吸收类型、牙根吸收程度的关系。结果 在75颗ERR邻牙中,67颗（89.3%）为无症状活髓牙。ERR邻牙的预后与患者的年龄相关（r=0.330,P<0.05）,年龄低于30岁者ERR邻牙均保持了无症状活髓。ERR邻牙的预后与性别、牙根数量、牙根吸收类型、牙根吸收程度无相关性（P>0.05）。结论 对于因相邻埋伏阻生牙导致的牙根外吸收而无临床症状的恒牙,有较大概率在阻生牙拔除术后保存活髓,建议密切随访观察,不必行预防性根管治疗。     

Playing wind instruments as a potential aetiologic cofactor in external cervical resorption: two case reports

AIM: To present two cases of external cervical resorption (ECR) on maxillary incisors, in which the primary aetiologic factor is suggested to be pressure trauma by frequently playing wind instruments. SUMMARY: The exact aetiological spectrum of ECR is still poorly understood. For resorption to occur, a defect in the cementum layer (trigger) is a likely prerequisite. Whilst the mechanism for continuation (stimulus) is still unclear, knowledge of potential predisposing factors is important in assessing patients at risk. Pressure generated by playing wind instruments could present an aetiological factor in ECR because it affects the cervical region of the root surface. The cases that are presented may confirm this hypothesis and the extent of resorption defects is shown by cone-beam computer tomography (CT) and micro-focus CT imaging techniques.     

Stability of the implant/abutment joint in a single-tooth external-hexagon implant system: clinical and mechanical review

Rigorous efforts have recently been made to reduce the recurrence of implant/abutment joint failure in single‐tooth implant restorations. However, the current knowledge about the stability of implant/abutment joints in an external hexagon implant system is incomplete. We reviewed clinical data regarding single‐tooth implant treatment with Brånemark implants, specifically the CeraOne abutment system (Nobel Biocare AB, Göteborg, Sweden). In vitro studies on joint stability were systematically assessed. Bending overload and the presence of misfit at the implant/abutment joint interface are the critical mechanical conditions that can make the joint unstable. Appropriate joint fitness and proper alignment of the implant should be assessed, and occlusal adjustment by narrowing the restoration width and flattening cuspal inclination should be applied to avoid bending moments caused by the lateral component of occlusal forces. Sufficient clinical reports of longer duration that evaluate and verify longer‐term success of the newly manufactured joint components were unavailable.     

Abutment rotational displacement of external hexagon implant system under lateral cyclic loading

Purpose This in vitro study investigated the effect of lateral cyclic loading with different load positions and periods on abutment rotational displacement (RD) of external hexagon implant system. Materials and Methods Four groups of five implant assemblies each were used. Each assembly consisted of Brånemark System® Mk IV implant (Nobel Biocare AB, Göteborg, Sweden), CeraOne® abutment (Nobel Biocare AB), and a cement‐retained casting. A cyclic load of 50 N was applied centrally and perpendicular to the long axis of the implant for groups A and B for 0.25 and 0.50 × 10⁶ cycles, respectively, while for groups C and D, the same load was applied at 4‐mm distance eccentrically for 0.25 and 0.50 × 10⁶ cycles, respectively. The displacement was evaluated by hand drawing a longitudinal line across the implant‐abutment interface. Before and after loading, the lateral distance between two reference points on the abutment and implant was measured under high resolution (×200) and the difference formed the RD value. The data were analyzed with one‐way analysis of variance and compared with Tukey test (α=0.05). Results Group D had the highest mean of RD value (55.00 ± 1.871 μm), while group A had the lowest (2.800 ± 0.837 μm). Groups A and B had a high statistically significant difference in RD values, as compared to groups C or D (p < .001). Moreover, group C had statistically significant difference from group D (p=.011). Conversely, no statistical significance was obtained when group A was compared with group B. Conclusion Within the limits of this in vitro study, the RD of the external hexagon joint components occurred significantly under eccentric lateral loading when compared to centric loading. The displacement increased significantly with longer period of eccentric lateral loading.     

Toxicity of concentrated sodium hypochlorite used as an endodontic irrigant

AIM: To present a clinical case that illustrates the toxicity of concentrated sodium hypochlorite (NaOCl) on vital tissues. SUMMARY: The severe clinical consequences of extruding concentrated NaOCl into the periradicular tissues during root canal irrigation are described. After diagnosis of external resorption in tooth 34, endodontic treatment was initiated. Following irrigation with a concentrated NaOCl solution, a rapidly developing swelling and haematoma were visible. During the next few days, an extensive bruise and local necrosis of the oral mucosa developed. After healing of the involved tissues, the canal was prepared and obturated. At this time, no clinical symptoms remained. KEY LEARNING POINTS: * The use of concentrated NaOCl as a root canal irrigant might cause severe clinical problems when extruded into vital tissues. * The present report confirms the known toxicity of NaOCl to soft tissues following inadvertent extrusion. * To avoid extrusion, it is always prudent to confirm the length and integrity of the root canal system before irrigating with concentrated solutions.     

左侧下颌骨髁突内陷性脱位1例

<正>1临床资料患者,女性,36岁,汉族。因"外伤致张闭口不能9 d"就诊。9 d前患者被石板砸倒后下颌着地致伤,伤后下颌不能活动,无法张闭口,影响进食。检查:左侧下颌面部皮肤可见一长约1 cm的     

A clinical report on distraction osteogenesis applied for Apert syndrome

This case report describes the orthodontic treatment done to an 11-year-old female patient having Apert syndrome, a genetic disorder manifested by craniofacial and limb anomalies. The orthodontic treatment was accompanied with distraction osteogenesis for forward advancement of the correction of midfacial hypoplasia. After the active treatment, a better facial profile and occlusion were achieved. The occlusion remained stable during the 2 years and 8 months follow-up.     

《黄帝内经》关、阖、枢理论解读

关、阖、枢理论出自《黄帝内经》,对其理论内涵的解读历代分歧甚大。本文通过还原其出处经文《灵枢·根结》《素问·阴阳离合论》《素问·皮部论》的成篇背景,提出关、阖、枢应视为经、络、皮部联系系统的功能模式,其中阳经之气受天阳之气的影响而布散于表,开气门而与天气相通,主外之皮肉筋骨;阴经之气受水谷之气充养,回输腑脏。阴阳经又以关、阖、枢的形式气化相通,构成人身内之脏腑、外之皮肉筋骨与外界沟通之门户。《素问·皮部论》补充了内外邪气按三阴三阳关-阖-枢传变的模式,并为用调经刺络法治疗外经病和脏腑病提供理论依据。