横腭弓增强支抗的研究

目的：评价临床矫治安氏Ⅱ类1分类错He病例使用横腭弓支抗的控制效果。方法：选择15－29岁安氏Ⅱ类1分类错He患者12例，分析用横腭弓增强支抗治疗前后的X线头影测量值的变化。结果：①6－－Ptm0、6－－So、6－CR－So、6-AP-So、1－－Ptm0、1－－So、1－－NA、1－－SN矫治前后改变极具显著性（P＜0．001）；②6－－PP于治疗后亦增大，有显著性（P＜0．05），但是∠GoGn-SN和ALFH／AFH的改变没有显著性；③横腭弓用于增强支抗时，磨牙前移量被控制在拔牙间隙的1／3内。结论：在常规治疗手段如Ⅱ类牵引及后牙段结扎固定的辅助下，横腭弓能够提供中到重度支抗；横腭弓能够对磨牙伸长进行较为有效的限制。     

钟摆矫治器联合颊侧推簧远移磨牙的疗效分析

目的：评价钟摆矫治器联合颊侧推簧远移磨牙的疗效.方法：选择40例牙性安氏Ⅱ类错（牙合）畸形的患者,随机均分为两组：钟摆矫治器联合颊侧推簧远移磨牙组（组1）和头帽口外弓远移磨牙组（组2）,在治疗开始前（T0）和远移磨牙完成时（T1）分别拍摄侧位头影定位片进行头影测量,t检验分析组内和组间的差异.结果：组1和组2远移磨牙的平均距离分别是（4.48±1.63） mm、（2.68±1.71） mm;组1和组2磨牙远中倾斜的平均角度分别是5.46°±3.23°、1.02°±2.16°;组1上颌中切牙未发生明显的唇倾和唇向移位,而组2上颌中切牙发生了较为明显的腭侧移位.结论：钟摆矫治器联合颊侧推簧远移磨牙可有效防止前牙支抗的丧失、控制磨牙的近中颊侧旋转.     

改良Jones装置推磨牙向后

在正畸临床治疗中,牙源性安氏Ⅱ类错　,常需推磨牙向后以开拓间隙,矫正磨牙至Ｉ类关系。我们采用改良Ｊｏｎｅｓ装置推磨牙向后,共治疗５例,取得良好效果。现将该矫治器的制作和临床应用体会介绍如下。 矫治器组成 矫治器选用Ｊｏｎｅｓ装置［１］,并对其进行改良,包括支抗和作用力两部分。（图１） 支抗部分为Ｎａｎｃｅ 腭托,在或上制作带环,颊侧焊托槽,腭侧用直径１．０ｍｍ不锈钢丝制作连接丝,埋于腭托内。腭托面积尽量大,近中至切牙腭侧,远中至第二双尖牙远中,边缘离开龈缘约３——５ｍｍ,并避开腭乳头。 作用力部分：…     

方丝弓技术矫治安氏Ⅱ类1分类错He

OBJECTIVE: To treat class II division 1 extraction cases by means of Edgewise technique. METHODS: 27 skeletal class II division 1 malocclusion patients were extracted 2 upper first premolars and 2 lower second premolars, and treated by Edgewise principles and sequential force system. They aged from 11 to 20. The duration of orthodontic treatment was 25.5 months on average(22-28 months). RESULTS: The patients' profile was much improved; Molar relation changed from class II to class I relationship; Anterior overjet and overbite are normal; Good occlusal intercuspation is also achieved. The ANB angle was significantly changed from 5.6 degrees +/- 2.2 degrees to 3.2 degrees +/- 1.4 degrees; Z angle was altered from 60.8 degrees +/- 5.8 degrees to 76.4 degrees +/- 6.6 degrees; Distance of AO-BO was reduced from 6.8 +/- 2.4 mm to 3.2 +/- 1.1 mm. CONCLUSIONS: Edgewise technique is an effective method for treatment of class II division 1 extraction cases.     

口外弓推磨牙远移矫治安氏Ⅱ类错殆12例临床分析

目的 研究口外弓推上颌磨牙远移矫治安氏Ⅱ类错殆后的组织变化。方法 用口外弓推磨牙远移治疗12例安氏Ⅱ类错he。通过治疗前后X线测量及模型测量进行分析比较。结果 磨牙关系均被纠正至安氏Ⅰ类关系。结论 口外弓推磨牙远移配合方丝弓矫治器是矫治安氏Ⅱ类错he简便有效的方法之一。     

口外弓椎磨牙向后治疗安氏Ⅱ类1分错He的分析研究

目的：探讨口外弓椎磨牙向后治疗安氏Ⅱ类１分类错Ｈｅ的机制。方法：对１２例安氏Ⅱ类Ｉ分类错Ｈｅ的少年进行口外弓椎磨牙向后治疗,第二期用方丝弓矫治器治疗;对两期相关的软硬组织进行Ｘ线头影测量。结果：口外弓椎磨牙向后治疗的治疗使颌骨、牙齿、软组织有不同程度的改变,主要通过抑制上颌骨,使下颌正常生长而使ＡＮＢ明显减小;口外力了使上中切牙倾斜度明显减小。方丝弓矫治器使治疗更完善。结论：口外弓椎磨牙向后配合方     

改良Nance弓矫治后牙锁(牙合)伴前牙深覆(牙合)的临床效果

目的探讨改良Nance弓矫治上颌第二磨牙正锁伴前牙深覆病例的临床效果。方法应用改良Nance弓矫治40例上颌第二磨牙正锁伴前牙深覆患者,对矫治前后X线头影进行测量分析和测量临床牙冠高度,并设空白对照组24例作对照。结果治疗组经过3~4个月的矫治,上颌第二磨牙正锁解除,前面高平均增加(2.63±0.57)mm,后面高平均增加(1.66±0.26)mm,覆平均减少(2.59±1.28)mm,上下前磨牙临床牙冠高度均有显著增加,下颌多于上颌。下磨牙临床牙冠高度亦明显增加,上磨牙不明显。结论改良Nance弓是一种简单有效的矫治上颌第二磨牙正锁的口内装置,并能快速打开咬合,尤其适用于深覆低角型患者。     

种植微螺钉支抗矫治下颌磨牙缺失患者的上牙前突伴拥挤

目的探讨微螺钉种植体作为支抗用于下颌磨牙缺失患者矫治上牙前突伴拥挤的临床效果。方法选择下颌单侧磨牙缺失、上牙前突伴拥挤的成年错!患者8例（年龄22~38岁）,在每位患者下颌磨牙缺失侧的第二前磨牙远中11~13 mm颊侧牙槽嵴处各种植1枚纯钛微螺钉,并以栓道固位方式在微螺钉的龈上部分附着自制微螺钉牵引帽,利用微螺钉牵引帽依次牵引同侧的下颌前磨牙、尖牙、切牙向远中移位,并利用牵引帽上的牵引钩行颌间Ⅱ类牵引。结果采用种植微螺钉作为支抗的8例患者治疗后均达到较理想的效果,前牙覆盖覆!和后牙尖窝关系均正常。疗程最长者24个月,最短者15个月,平均20.8个月。结论微螺钉种植体支抗可以用于下颌磨牙缺失的上牙前突伴拥挤患者的矫治。     

Variations of Palatal Canal Morphology in Maxillary Molars: A Case Series and Literature Review

A series of challenging cases with unusual canal anatomy in the palatal roots of maxillary first and second molars is presented. A review of the literature was done to elucidate the prevalence of anatomic variations in the palatal canal of maxillary first and second molars. An uncertain or indefinite radiographic appearance of the palatal canal, or eccentric deviation of the master cone or previous root canal filling was considered an indication of a bifurcated palatal canal. Five maxillary molars with a bifurcated palatal canal were identified. A MEDLINE database search was performed to identify studies on the palatal canal morphology of maxillary first and second molars. Data were categorized based on the methodology used in each study. The overall prevalence of anatomic variations in the palatal canal of maxillary first and second molars was less than 2%; however, anatomic variations occurred more frequently in certain ethnic groups, reaching up to 33% in maxillary first molars and up to 14% in maxillary second molars. This case series showed that even experienced endodontic clinicians can miss a bifurcated palatal canal if they are not aware of or overlook the hidden clues for these anatomic variations. The traditional assumption of an exclusively single-canal anatomy in palatal canals of maxillary molars needs to be changed, even though it is the most prevalent anatomy. The overall low percentage of more than 1 palatal canal in maxillary molars is disturbingly misleading, because in certain ethnic groups this prevalence can be considerably higher.     

Maxillary Molars With Morphologic Variations of the Palatal Root Canals: A Report of Four Cases

IntroductionThe purpose of this article was to show the importance of the knowledge of the anatomy of root canals. Unusual root and root canal morphologies associated with both buccal roots of upper molars have been recorded in several studies in the literature. However, scientific information focusing on variations of the palatal root is rare.MethodsIn this report, four cases are presented involving the root canal treatment of maxillary first and second molars with unusual morphologic configurations of the palatal root canals.ResultsDuring root canal treatment, type IV and V configurations as defined by Vertucci of the palatal canals of two first and two second maxillary molars were identified. After mechanical instrumentation, the canals were obturated. Radiologic and clinical re-evaluation showed no signs of inflammation.ConclusionsThis report describes and discusses the possibility of different root and canal variations of the maxillary molars from a clinical point of view. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. Therefore, careful examination of radiographs and internal anatomy of teeth is essential.     

机用镍钛Hero642预备磨牙弯曲根管的临床研究

目的探讨机用镍钛器械Hero642应用于磨牙弯曲根管预备的效果。方法选择根管弯曲的磨牙86颗,先采用小号K锉疏通根管,将根尖部预备至15号后,再以机用镍钛器械Hero642完成根管预备,侧向加压充填根管,根据治疗前后的x线片评价根管预备和充填效果。结果86颗磨牙共有274个根管,264个根管形态良好,无台阶、根尖堵塞、根管偏移及侧壁穿孔等并发症发生。根充恰填256个,8个根管超充,10个根管未能完全扩通,无法到达根尖孔而欠充或做塑化治疗。结论手用锉疏通弯曲根管的根尖段后再以机用镍钛器械Hero642完成根管预备,可获得良好的成形效果且较少产生并发症。     

Prognosis of Second Molars with External Root Resorption Caused by Adjacent Embedded Third Molars

IntroductionThis prospective study was designed to determine the prognosis of second molars with external root resorption (ERR-M2s) caused by embedded third molars (EM3s) following EM3 removal and explore related predictors.MethodsThis study consecutively enrolled 58 participants who had asymptomatic second molars with apical external root resorption caused by EM3s. EM3s were extracted, and follow-up examinations were conducted at 1 week, 4 weeks, and 6 months. The primary outcome was prognosis of ERR-M2s after third molar extraction without any further intervention, as assessed via clinical and radiographic examinations. Potential predictors (sex, age, number of roots, EM3s position, type and degree of external root resorption) of prognosis were analyzed via univariable and multivariable analyses.ResultsA total of 63 ERR-M2s from 58 patients (16 males and 42 females; 19–57 years of age) were evaluated. At the last follow-up, 56 teeth (89%) remained asymptomatic and normal response to heat and cold tests. According to univariable analyses, ERR-M2s were more likely to remain normal response to heat and cold tests in younger patients. In the multivariable analysis, older age (odds ratio, 1.118; 95% confidence interval, 1.026–1.219; P < .05) and the type of all roots affected (odds ratio, 0.073; 95% confidence interval, 0.007–0.754; P < .05) were significantly associated with poor prognosis.ConclusionsAsymptomatic ERR-M2s have a high probability of remaining normal pulp without further intervention after EM3 extraction, especially in younger patients. No intervention except follow-up and observation is necessary.     

少牙畸形患者牙弓长度和宽度的临床研究

目的研究少牙畸形患者牙弓的长度和宽度,为临床诊治提供参考。方法选取少牙畸形与正常的牙模型各50副,用游标卡尺测量并计算牙弓长度和宽度的各项参数,采用ANOVA法进行统计分析。结果少牙畸形患者较正常的上、下牙弓长度分别少4.40mm和2.80mm,上、下颌尖牙宽度分别少2.82mm和2.70mm,上、下颌磨牙宽度分别少3.40mm和1.80mm。两组测量项目的差异均有统计学意义(P<0.01)。结论正畸治疗时,应当考虑到少牙畸形患者的牙弓长度和宽度均较正常小。     

庆大霉素与曲安奈德局部注射在下颌阻生智齿拔除后的临床探讨

目的：探讨下颌阻生智齿拔除后局部封闭．减少术后并发症的方法。方法：将120例拔除下颌阻生智齿（低位或阻生）的患者随机分成两组,实验组拔牙后,用庆大霉素及曲安奈德创口周围局部注射,对照组拔牙后创口常规处理。术后进行随访,记录术后肿胀、疼痛、开口受限、干槽症4项并发症情况,对其进行检验。结果：实验组拔牙术后的并发症明显少于对照组,两组并发症比较差异均有统计学意义（P〈0．05）。结论：下颌阻生智肯拔除术后,创口周围注射庆大霉素和曲安奈得,可减少并发症的发生。