无托槽隐形矫治器和直丝弓矫治器对切牙牙根吸收的影响

目的:评估使用无托槽隐形矫治器和直丝弓矫治器的患者切牙牙根吸收情况.方法:分别选取28例使用无托槽隐形矫治器(实验组)和直丝弓矫治器(对照组)的患者,分析患者术前、术中6个月及术后的锥形束CT(CBCT)影像.通过测量各时间段的牙根长度,比较2组患者牙根吸收有无差异.对于牙根长度未见变化的患牙,通过CBCT检测其有无单纯唇腭侧和近远中骨质吸收.采用SPSS16.0软件包对数据进行统计学分析.结果:术后6个月,实验组患者47.3％的牙出现牙根吸收,显著少于对照组的68.8％ (P＜0.05).2组患者上颌中切牙牙根吸收的发生率均高于其他牙(实验组为55％,对照组为75％).矫治完成后,对照组牙根吸收的发生率上升到85.3％,而实验组上升到68.3％(P＜0.05).部分牙根长度未见减少的牙也存在局部根吸收,骨吸收最常发生在牙根的腭侧面(实验组为18％,对照组为14％).结论:与传统直丝弓矫治器相比,使用无托槽隐形矫治器的患者切牙牙根吸收程度较小.     

Pendulum and modified pendulum appliances for maxillary molar distalization in Class II malocclusion – a systematic review

Objective: The main purpose of the present systematic review was to evaluate the quantitative effects of the pendulum appliance and modified pendulum appliances for maxillary molar distalization in Class II malocclusion.

Materials and methods: Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus and key journals and review articles; the date of the last search was 30 January 2017. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP).

Results: In total, 203 studies were identified for screening, and 25 studies were eligible. The quality assessment rated four (16%) of the study as being of strong quality and 21 (84%) of these studies as being of moderate quality. The pendulum appliances showed mean molar distalization of 2–6.4?mm, distal tipping of molars from 6.67° to 14.50° and anchorage loss with mean premolar and incisor mesial movement of 1.63–3.6?mm and 0.9–6.5?mm, respectively. The bone anchored pendulum appliances (BAPAs) showed mean molar distalization of 4.8–6.4?mm, distal tipping of molars from 9° to 11.3° and mean premolar distalization of 2.7–5.4?mm.

Conclusions: Pendulum and modified pendulum appliances are effective in molar distalization. Pendulum appliance with K-loop modification, implant supported pendulum appliance and BAPA significantly reduced anchorage loss of the anterior teeth and distal tipping of the molar teeth.     

差动直丝弓矫治技术打开咬合过程中不同磨牙后倾弯曲度对下颌前牙及牙周膜应力分布的影响

目的：研究在差动直丝弓矫治技术打开咬合过程中,不同下颌磨牙后倾弯角度对下颌前牙应力分布及位移趋势的影响。方法利用志愿者锥体束CT,建立下颌牙列和差动直丝弓矫治器的三维有限元模型,模拟下颌30°、35°、40°和45°四种后倾弯,对模型加载进行有限元分析。结果下颌前牙牙根和牙周膜所受应力均随后倾弯度数增大而增大,当后倾弯角度大于40°时应力出现减小,其应力分布符合非控制性倾斜移动的特点。下颌前牙的初始位移趋势随后倾弯的增大而增大,当大于40°时初始位移趋势开始减小。下颌尖牙在颊舌向上表现为冠颊倾,下颌切牙冠唇倾,在垂直向上表现为先尖牙再切牙的顺序压低,在近远中向均表现为冠近中移动趋势。结论在差动直丝弓打开咬合阶段,通过调整磨牙后倾曲的角度可获得下颌前牙段适宜的压入以及匹配的上下颌牙弓宽度。     

生理性支抗Spee氏弓矫治器矫治安氏Ⅱ1错(牙合)拔牙病例的临床体会

目的 应用PASS矫治器(生理性支抗Spee氏弓矫治器)对安氏Ⅱ1错(牙合)进行矫治,观察其临床效果.方法 选取20例安氏Ⅱ1错(牙合)畸形患者,拔除4个第一双尖牙,应用PASS矫治器进行矫治,对治疗前后头影测量项目进行统计学分析.结果 20例患者平均疗程16.2±2.2月.矫治后ANB角减小0.99°,U1-SN角减小16.06°,U1-L1角增加14.60°,U1-NA减小7.13 mm,L1-NB减小2.01 mm,前牙覆(牙合)和覆盖分别减小了1.99 mm和6.88 mm,以上测量项目变化有统计学意义.结论 应用PASS矫治器对安氏Ⅱ1错(牙合)畸形矫治能得到很好的矫治效果.     

正畸辅助儿童髁突囊内骨折外脱位伴下颌后缩的闭合性治疗

目的 ：尝试正畸辅助闭合性治疗儿童髁突囊内骨折外脱位伴颏部骨折及下颌后缩,并观察其短期治疗效果。方法 ：1例9岁儿童外伤后15 d就诊,临床及影像学检查诊断为颏部骨折,双侧髁突囊内骨折外脱位,伴下牙弓增宽、下颌后缩。取模设计模型外科,制作Herbst矫治器。全麻下手法复位双侧髁突并缩窄下牙弓,同时戴入矫治器前移下颌。结果 ：配戴1个月后去除矫治器,随访6个月后患者咬合关系正常,下颌运动无碍,锥形束CT（CBCT）显示双侧髁突愈合改建良好,颏部骨折对位愈合。结论 ：借助Herbst矫治器的辅助,可闭合性治疗儿童髁突骨折外脱位伴颏部骨折及下颌后缩,短期随访获得了良好的咬合关系、髁突形态及下颌功能。     

HM-W1A型经皮微波凝固肿瘤治疗仪的研制

通过HM－W1A型经皮微波凝固肿瘤治疗仪的研制，我们探索出扩大微波凝固范围、改善凝固形态的有效途径，使该疗法更有利于对较大瘤体实施治疗，从而达到减少穿刺次数、提高肿瘤根治率的目的。     

Urostomy appliances and stoma care routines. The relation to peristomal skin complications

The aim of the study was to describe types of appliances and stoma care routines and evaluate their relation to peristomal skin complications. Sixty-six patients with a cutaneous uretero-ileostomy were interviewed and the peristomal skin was assessed according to Classification of Peristomal Skin (CPS). The results show a conservatism regarding the types of appliance and the stoma care routines. More than half of the patients used the same product at follow-up as they were initially fitted with three to 14 years earlier. The routines adopted by the patients were often inadequate, resulting in skin complications. Continuous exposure of the skin to urine by creation of a too wide opening in the face-plate and infrequent changing of the appliance resulted in development of pseudoverrucose skin lesions.     

Fatigue resistance of removable orthodontic appliance reinforced with glass fibre weave

The aim of this study was to measure the fatigue resistance of fibre-reinforced composite (FRC) reinforced polymeric parts of a removable orthodontic appliance beside the clasp. The effect of quantity and position of FRC-reinforcement were investigated. In addition, the influence of water storage on the fatigue properties was determined. The test specimens for eight groups (n=6) were manufactured from autopolymerizing acrylic resin. Polymethylmethacrylate pre-impregnated woven glass fibre was used as reinforcement of acrylic resin specimens at the region of steel wire clasp. The test specimens of the control group were not reinforced. In the second group, the test specimens were reinforced with one fibre layer (thickness: 0.06 mm) on the tension side, and in the third and fourth group with two fibre layers. Fatigue resistance was measured by applying repeated bending force to the clasp. The highest fatigue resistance values were achieved when the test specimens were fibre-reinforced with two fibre layers. The lowest fatigue resistance values resulted when the test specimens were not reinforced (P=0.046, anova). Water storage had a tendency to decrease the fatigue resistance in all fibre reinforced test specimen groups. The results suggest that use of the woven polymer pre-impregnated glass FRC-reinforcement increases the fracture resistance of orthodontic appliance made of acrylic polymer.     

Role of parental variables in predicting facial growth after treatment of anterior crossbite

A pilot study was done to determine whether parental cephalometric variables could be used to better predict craniofacial dimensions in their offspring. The sample consisted of lateral roentgenographic cephalograms from 41 children who had been treated with functional appliances for anterior crossbites and from their respective parents. The actual mandibular prognathic growth change of each child after treatment was determined from two profile radiographs over a 3-year period. Morphologic features after treatment and those of the respective parents were compared with the observed yearly growth change, and the predictive values were calculated by means of uni- or multivariate analysis. The best fit predictive formula was obtained by the total observation of variables from both children and their parents by means of multiple regression analysis in which the correlation coefficient exceeded 0.9 despite a value of less than 0.5 when the variables were analyzed separately by simple regression analysis. Thus, to predict the craniofacial growth for a given type of child, the dimensions of the child in addition to those of his or her parents (hereditary) seem to be a valid approach.     

Multidisciplinary Management of the Airway in a Trauma-Induced Brain Injury Patient

Laryngomalacia occurs in some brain injury patients secondary to global muscle hypotonia. Surgical therapies for epiglottis prolapse have centered around removal or reshaping of the epiglottis. This approach has brought mixed success and frequent complications. We present a case that demonstrates successful nonsurgical treatment of a 33-year-old male brain injury patient with moderate obstructive sleep apnea that is believed to be a consequence of post-brain injury nocturnal epiglottis prolapse. The presence of a tracheostomy performed at the time of emergency surgery had become an emotional and physical barrier to our patients recovery. The tracheostomy could only be reversed if the obstructive sleep apnea disorder could be managed in an alternative fashion. A titratable mandibular repositioning appliance was prescribed and its effectiveness was demonstrated with nasolaryngoscopy and polysomnography.After initially fitting the oral appliance, a period of accommodation and gradual protrusive adjustments was allowed. Subsequent confirmation polysomnography demonstrated improvement, but not suitable resolution, of disordered breathing events. However, an additional 1.25-mm protrusive titration of the oral appliance during the course of the confirmation polysomnogram led to therapeutic success. The patients tracheostomy was subsequently reversed with significant quality of life benefits.