下颌切牙先天缺失错He畸形的临床矫治

目的：探讨下颌切牙先天缺失错颌畸形拔牙矫治的影响因素。方法：对已完成的23例下颌切牙缺失错He畸形病例矫治效果进行回顾性研究。结果：10例矫治后对缺失下切牙修复，11例进行拔牙矫治，2例直接进行矫治。矫治后牙弓后段上下牙列咬合关系良好，前牙覆He覆盖基本正常。结论：在下颌切牙先天缺失错He畸形矫治中，决定拔牙的重要因素依次为面型，前牙覆He覆盖关系，磨牙关系及尖牙关系。此类错He病例Bolten指数不调，在拔牙矫治中应将上述前两个因素作为重点考虑。     

上海地区上前牙先天缺失患者牙颌面形态分析

目的：了解上海地区上前牙先天缺失儿童的牙颌面形态特征，探讨上前牙先天缺失对颌面部生长发育的影响。方法：对37例上前牙先天缺失儿童进行X线头影测量分析，并与正常值比较。结果：上前牙先天缺失儿童头影测量无性别差异，与正常值比较，上前牙先天缺失儿童颌凸角，ANB，AoBo减小，上下牙槽座角增大，Y轴角，下颌平面角减少，He平面角减少，上中切牙倾角大，下中切牙倾角减小，软组织面凸角减少，上唇倾角增大，鼻唇角减少，结论：上前牙先天缺失可引起上颌发育不足，对下颌大小无影响，但可引起下颌平面逆时针旋转。     

自攻微螺钉种植体支抗矫治先天缺牙所致中线偏斜

患者梁某，女，19岁。主诉：左上颌侧牙齿缺失，上前牙间隙，上中线偏，要求正畸治疗。 一、临床检查 面部正侧面观无异常。恒牙[牙合]，左上颌侧切牙先天缺失，缺牙间隙减小，左侧尖牙与第一前磨牙间隙2mm左右，左侧尖牙反[牙合]。上中切牙左侧移位并倾斜致使上颌中线左偏；左侧尖牙近中倾斜，相应部位牙槽骨和牙弓欠丰满。前牙浅覆[牙合]浅覆盖，磨牙关系为：右侧中性，左侧远中。下前牙轻度拥挤（图1）。     

先天缺牙与牙形态、大小异常相互关系的研究

目的 探讨先天缺牙与牙形态异常及牙大小异常的相互关系。方法 对79例先天缺牙患者的缺牙部位、缺牙数目，余留牙异常的牙体形态进行分析。并按缺牙程度及部位分成4组，测量其牙冠宽度。结果 （1）上颌侧切牙、下颌中切牙为临床最常见牙先天缺失部位，上颌中切牙，上下颌第一磨牙为牙列中最不易先天缺失的牙齿，但上颌中切牙在先天缺牙患者中常呈轻度的锥形牙冠。（2）先天缺牙常伴牙齿形态异常，以上颌侧切牙，下颌尖牙、上颌第二前磨牙，上下颌第二磨牙多见。（3）轻度先天缺牙患者余留牙大小无异常，随着先天缺牙严重程度增加，前牙有逐渐减小趋势而后牙大小较稳定。结论 （1）上颌侧切牙为牙列中最不稳定的牙齿：（2）牙齿形态、大小、数目异常可能是一个连续的变异过程，可能为同一机制的不同表现。     

基于CBCT的下颌前牙区颌骨形态学研究

[摘要]目的：利用锥形束CT（codebeamcomputedtomography,CBCT）图像研究测量下颌前牙区的颌骨形态和宽度,为临床种植手术提供治疗依据。方法：选取2011年--2013年间50名成年受试者的CBCT检查结果,利用CBCT图像对下颌前牙区颌骨外形、唇舌侧宽度、近远中距离等进行观察和测量。结果：1．下颌前牙区颌骨形态唇侧均为凹形,最凹点位于下颌骨上中份,舌侧外形多样化,凸形比例最高。2．下颌骨前牙区颌骨唇舌侧宽度在下颌骨中1／2和下颌骨下缘较宽,在牙槽嵴顶和根尖区较窄。3．左右尖牙、侧切牙、中切牙于牙槽嵴顶的近远中距离是4．46～6．94mm,尖牙最长,侧切牙次之,中切牙最小。结论：下颌前牙缺失后,尤其是下颌侧切牙或中切牙个别缺失,如行种植修复近远中距离可能不足,易损伤邻牙;植入种植体等手术时应当注意下前牙区颌骨外形,避免因倒凹导致唇舌侧穿通;CBCT可作为下颌前牙区种植手术术前的常规影像学检查手段。     

下颌切牙先天缺失错（牙合）畸形的临床矫治

目的:探讨下颌切牙先天缺失错颌畸形拔牙矫治的影响因素.方法:对已完成的23例下颌切牙缺失错牙合畸形病例矫治效果进行回顾性研究.结果:10例矫治后对缺失下切牙修复,11例进行拔牙矫治,2例直接进行矫治.矫治后牙弓后段上下牙列咬合关系良好,前牙覆牙合覆盖基本正常.结论:在下颌切牙先天缺失错牙合畸形矫治中,决定拔牙的重要因素依次为面型,前牙覆牙合覆盖关系,磨牙关系及尖牙关系.此类错牙合病例Bolten指数不调,在拔牙矫治中应将上述前两个因素作为重点考虑.     

恒前牙髓室解剖影像学的初步研究

目的 探讨中国人恒前牙髓室影像解剖学特征及其与牙体外表特征的关系。方法 采用游标卡尺测量137个离体恒前牙冠长、冠宽、冠厚等牙体解剖指标,然后采用平行投照技术拍摄唇舌向和近远中向X线片,并采用Photoshop 8.0软件测量髓室最大唇舌径、最大近远中径、髓室高及舌面髓壁距等影像解剖指标,计算髓室最大唇舌径与冠厚之比、髓室最大近远中径与冠宽之比、髓室高与冠长之比和髓室顶厚,得出以上指标的变异系数。结果 ①上下颌尖牙的髓室近远中径与冠宽之比与其余牙位间的差异有统计学意义（P<0.05）,而上下颌尖牙间则无统计学差异,上下颌中切牙、侧切牙间此比值的均值也无统计学差异（P>0.05）。②髓室指标的变异远大于牙体外表指标的变异程度。③舌面髓壁距的变异系数最小。④除下颌尖牙外,髓室的最大近远中径变异最大。结论 恒前牙的舌面髓壁距可以作为临床开髓洞深的参考指标;而开髓的时候,不要轻易向近远中向扩展。     

安氏II类2分类错He与先天性牙异常的关系

目的：为了验证安氏II类2分类错He与先天性牙异常如过小侧切牙、釉质发育不良、多生牙、易位牙、尖牙阻生和缺牙之间存在的关系。方法：对100例年龄12～42岁未经历正畸治疗的II类2分类错He患者的病史、口内、X片和牙模型进行检查，并进行样本百分比分析。结果：结果显示牙异常者占50．00％。7．00％的患者上侧切牙釉质发育不良，28．00％过小侧切牙，4．00％尖牙阻生，9．00％下切牙缺失，易位牙为2．00％，无一例多生牙。30．00％前牙Bolton比值不协调。结论：安氏II类2分类错He与过小侧切牙、釉质发育不良、先天缺牙密切相关。II类2分类错He前牙Bolton比值不协调的主要因素是过小侧切牙和下切牙缺失。     

前牙区暂时性错He两年纵向观察分析

儿童替牙早期，常在前牙区出现恒中切牙间隙，恒切牙歪斜、拥挤等症状。通过取牙Ｈｅ石膏模型和摄全景片的方法，对９１名儿童从小学１年级起连续观察２年。发现：（１）中切牙间隙发生率第２年显著低于第１年；（２）切牙歪斜发生率也呈明显下降趋势；（３）前牙拥挤情况２年相仿。认为中切牙间隙和切牙歪斜的发生都与侧切牙胚有关，随恒侧切牙的萌出，症状得到改善，前牙区的拥挤可能与同名乳恒切牙近远中径差值有关，因此双尖牙替     

壮族人群恒前牙根管弯曲度测定

目的了解壮族人群恒前牙的根管弯曲情况。方法收集新鲜拔除的壮族人群恒前牙245颗,采用间接影像学手段观察其根管类型和弯曲形状,在Schneider法和Sch覿fer法的基础上,结合电子测量尺软件测量分析218颗Ⅰ型根管牙齿的弯曲度、弯曲半径和弯曲长度。结果壮族人群恒前牙以Ⅰ型根管为主,有13颗下颌中切牙和12颗下颌侧切牙为Ⅱ、Ⅲ、Ⅳ型根管。上颌中切牙、侧切牙、尖牙以及下颌中切牙、侧切牙、尖牙Ⅰ型根管近远中向弯曲发生率分别为40%、80%、77%、65%、66%、73%,唇舌（腭）向弯曲发生率分别为62%、69%、70%、62%、41%、61%。弯曲部位多在根尖1/3,多为中度弯曲;上颌尖牙在近远中向上的根管弯曲度最大,下颌尖牙在唇舌（腭）向上的根管弯曲度最大;上颌侧切牙在近远中和唇舌（腭）2个方向上的根管弯曲半径及弯曲长度均较小。结论壮族人群恒前牙根管弯曲情况较复杂,其下颌切牙Ⅱ、Ⅲ、Ⅳ型根管发生率较高。     

下颌切牙先天缺失女性患儿的牙颌面形态分析

目的研究下颌切牙先天缺失女性患儿的牙颌面形态特征,探讨下颌切牙先天缺失对其颌面部生长发育的影响。方法选取47例12～15岁的下颌切牙先天缺失女性患儿(实验组)进行X线头影测量分析,与21例不缺牙的个别正常同龄女性儿童(对照组)比较。结果缺失一颗下前牙与两颗下前牙者,X线头影测量无显著差异;将两者合并,与对照组比较,缺牙组UI-NA(mm)、IMPA显著减小,ANB、NA-PA、MP-SN、N-ME、ANS-ME、下颌长显著增加。结论下颌切牙先天缺失可以引起女性患儿Ⅱ类错,上前牙舌侧移位、下前牙舌倾,下颌骨的顺时针旋转,全面高、下面高以及下颌骨长度增加。     

Tooth sizes in nonsyndromic hypodontia patients

Objective:To evaluate and compare the sizes of teeth in mild and severe hypodontia patients with those of healthy controls.Materials and Methods:Dental casts of 154 patients with two or more congenitally missing teeth were obtained. Patients were divided into two groups according to severity of hypodontia. Group I (mild) consisted of 118 patients with two to five missing teeth. Group II (severe) consisted of 36 patients with six or more missing teeth. In addition, a control group was included, which consisted of 50 patients who had an Angle Class I jaw relationship and no missing teeth. Mesiodistal and labiolingual dimensions of the teeth were measured with a digital caliper on dental casts. The independent-samples t-test was used to evaluate the effect of gender on measurements. Intergroup differences for mesiodistal and labiolingual dimensions were evaluated with analysis of variance and post hoc Tukey tests.Results:Statistically significant differences were found between girls and boys with hypodontia in the mesiodistal dimension of the mandibular first premolar and the labiolingual dimension of the mandibular lateral incisor (P < .01). Mesiodistal and labiolingual width measurements of the teeth of hypodontia patients showed statistically significant differences compared with the control group (P < .05). Most teeth showed significant dimensional reductions in severe hypodontia compared with mild hypodontia (P < .05).Conclusions:The mesiodistal and labiolingual dimensions of teeth in both mild and severe hypodontia groups were smaller than those in control subjects. The reduction in size was more excessive in the severe hypodontia group. The teeth showing the greatest difference in tooth dimensions were the maxillary lateral incisor (in mesiodistal dimension) and the mandibular canine (labiolingual dimension).     

个别下切牙先天缺失症临床矫治的研究

目的 :探讨先天缺失下切牙各种错牙合畸形类型和达到个别正常牙合的方法。方法 :选取 10例完成正畸治疗的各类个别下切牙先天缺失的错牙合畸形患者 ,男 3例 ,女 7例 ,平均年龄 15.4岁 ,分别测量治疗前后的模型和头颅侧位片 ,调整颌位和牙位 ,通过Bolton指数指导 ,采用片切、拔牙、倾斜牙轴达到正常的前牙覆牙合覆盖。结果 :10例患者都达到了后牙尖窝交错咬合 ,前牙覆牙合覆盖正常 ,尖牙间宽度不变或减少。结论 :有下切牙先天缺失的错牙合畸形 ,通过颌位结合牙位的调整 ,都能达到个别正常牙合的功能和美观的效果     

Mini-implants for en masse intrusion of maxillary anterior teeth in a severe Class II division 2 malocclusion

This case report describes the treatment of a 16-year-old post pubertal male patient with a severe Class II division 2 malocclusion and 100% deep bite. In the first phase of treatment, a 'Jones-Jig' molar distalization appliance was used to distalize the maxillary molars by more than 6 mm, to achieve a Class I molar relation. In the second phase of treatment, mini-implants were inserted between the roots of the maxillary lateral incisor and canine to intrude all the maxillary anterior teeth en masse in a single step. Four millimetres of intrusion was achieved. The implants remained stable throughout treatment. In the mandibular arch the incisors were proclined to alleviate the severe crowding. Good overjet and overbite was achieved and has been maintained one year after completion of active orthodontic treatment.     

下颌前牙唇侧骨壁厚度及倾斜角度对即刻种植术前设计的影响

目的: 利用锥形束CT（cone-beam CT,CBCT）对下颌前牙唇侧骨壁厚度及倾斜角度进行测量分析,为下颌前牙区的即刻种植术前设计提供参考依据。方法: 选取青岛大学附属医院口腔科135例（男67例,女68例）下颌恒牙列完整的CBCT资料,分别测量牙槽嵴顶处（P1）、牙根中点处（P2）、根尖处（P3）3个位点的唇侧骨壁厚度、下前牙长轴与牙槽骨长轴的角度。采用SPSS 23.0软件包对数据进行统计学分析。结果: 下颌中切牙、侧切牙、尖牙唇侧牙槽嵴顶处骨板厚度分别为（0.65±0.24）mm、（0.66±0.28）mm、（0.57±0.29）mm,根中处骨板厚度分别为（0.58±0.35）mm、（0.47±0.23）mm、（0.58±0.30）mm,根尖处骨板厚度分别为（3.45±1.28）mm、（3.87±1.25）mm、（4.60±1.32）mm;下颌中切牙、侧切牙、尖牙牙体长轴与牙槽骨长轴角度分别为5.43°±2.30°、7.22°±3.12°、6.28°±2.65°;相同牙位左右侧之间、不同性别之间各测量值之间无显著差异。结论: 下颌前牙唇侧骨壁厚度菲薄,下颌前牙倾斜角度较小,可为下颌前牙区的即刻种植术前设计的制定提供参考依据。     

Mini-implants for en masse intrusion of maxillary anterior teeth in a severe Class II division 2 malocclusion

Abstract

This case report describes the treatment of a 16-year-old post pubertal male patient with a severe Class II division 2 malocclusion and 100% deep bite. In the first phase of treatment, a ‘Jones-Jig’ molar distalization appliance was used to distalize the maxillary molars by more than 6 mm, to achieve a Class I molar relation. In the second phase of treatment, mini-implants were inserted between the roots of the maxillary lateral incisor and canine to intrude all the maxillary anterior teeth en masse in a single step. Four millimetres of intrusion was achieved. The implants remained stable throughout treatment. In the mandibular arch the incisors were proclined to alleviate the severe crowding. Good overjet and overbite was achieved and has been maintained one year after completion of active orthodontic treatment.     

正畸治疗中阻生牙助萌术1例

目的 以正畸治疗中阻生牙助萌术为例,探讨正畸患者的牙周手术设计中应注意的问题。诊治过程：25岁男性患者,牙龈呈炎症表现,牙列不齐,右上颌侧切牙阻生。前牙深覆牙合,双侧第一磨牙及尖牙远中关系,右上颌中切牙和尖牙间存在间隙。前期通过正畸治疗排齐牙列,并开辟右上颌侧切牙处的间隙。在完成牙周基础治疗的前提下,设计偏腭侧切口,在有效暴露阻生牙的前提下尽可能保存所有软组织,同时根据正畸牙移动的目标位置行骨增量和软组织增量,术后牵引并排齐右上颌侧切牙。结果 通过合理的牙周手术设计,本病例在正畸过程中保持了牙周软硬组织的健康。结论 正畸患者的牙周手术设计应同时关注正畸需求和牙周健康。     

基于锥形束CT对下颌前牙根管系统构型的初步研究分析

目的:应用锥形束CT研究海口地区下颌前牙的根管形态,为牙体牙髓病治疗提供参考依据。方法:选取海南口腔医院影像科CBCT影像资料库中男性、女性各300例,按年龄分6组:12~20、21~30、31~40、41~50、51~60、61~70岁,每组男、女各50例。采用配套软件处理,根据Vertucci分类法观察下颌前牙根管系统的构型。结果:下颌中切牙、侧切牙和尖牙的多根管率分别为11.75%、23.5%和10.41%,下前牙的多根管发生率有统计学差异(P<0.05)。不同年龄组,下颌中切牙,侧切牙多根管发生率,有显著性统计学差异(P<0.001),下颌尖牙多根管发生率无统计学差异(P>0.05)。下前牙多根管时,其根管分叉至解剖性根尖的距离,下颌中切牙为(8.56±2.08)mm,下颌侧切牙为(9.43±1.93)mm,下颌尖牙为(10.60±2.01)mm。不同牙位之间比较,该距离均有统计学差异(P<0.05)。性别间比较,仅下颌中切牙根管分叉至解剖性根尖的距离有统计学差异(P=0.020,P<0.05)。不同年龄组间比较,下颌侧切牙和下颌尖牙的根管分叉至解剖性根尖的距离有统计学差异(P=0.004,P=0.04,P<0.05)。结论:下颌前牙单根多管发生率在10.41%~23.5%区间、多根管发生率和年龄相关性密切。     

Extreme skeletal open bite correction with vertical elastics

Severe skeletal open bites may be ideally treated with a combined surgical–orthodontic approach. Alternatively, compensations may be planned to camouflage the malocclusion with orthodontics alone. This case report describes the treatment of an 18-year-old man who presented with a severe open bite involving the anterior and posterior teeth up to the first molars, increased vertical dimension, bilateral Class III molar relationship, bilateral posterior crossbite, dental midline deviation, and absence of the maxillary right canine and the mandibular left first premolar. A treatment plan including the extraction of the mandibular right first premolar and based on uprighting and vertical control of the posterior teeth, combined with extrusion of the anterior teeth using multiloop edgewise archwire mechanics and elastics was chosen. After 6 months of alignment and 2 months of multiloop edgewise archwire mechanics, the open bite was significantly reduced. After 24 months of treatment, anterior teeth extrusion, posterior teeth intrusion, and counterclockwise mandibular rotation were accomplished. Satisfactory improvement of the overbite, overjet, sagittal malocclusion, and facial appearance were achieved. The mechanics used in this clinical case demonstrated good and stable results for open-bite correction at the 2-year posttreatment follow-up.