上颌尖牙埋伏阻生患者牙弓形态及拥挤度的研究

目的 上颌尖牙唇侧和腭侧埋伏阻生患者的牙弓宽度、长度、拥挤度与正常(牙合)个体之间是否存在差异.方法 经CT检查上颌尖牙埋伏阻生患者104名,年龄11-28岁.尖牙唇侧阻生患者57名,腭侧阻生患者47名,对其牙弓宽度、长度、拥挤度进行测量,并和正常(牙合)个体进行对照研究.结果 上颌尖牙唇侧埋伏阻生患者82.5%伴有牙弓中重度拥挤,上颌尖牙腭侧埋伏阻生患者57.4%的牙弓基本无拥挤.上颌尖牙埋伏阻生患者中,无论是唇侧埋伏还是腭侧埋伏,其牙弓长度与正常(牙合)无差异.双尖牙区牙弓宽度减小.结论 国人上颌尖牙埋伏阻生患者的牙弓宽度、长度、拥挤度的特点与白种人不同.     

上颌埋伏阻生尖牙在锥形束CT和曲面体层片中的位置分布及特征研究

目的　通过分析上颌埋伏阻生尖牙在曲面体层片上牙冠和牙根所在区域、牙轴倾斜度及牙齿长度,对照其在锥形束CT（cone-beam computed tomography,CBCT）上的位置,找出上颌埋伏阻生尖牙的曲面体层片预测因素。方法　选取2006—2018年于中国医科大学附属口腔医院正畸科就诊的单侧上颌埋伏阻生尖牙患者135例,共计上颌埋伏阻生尖牙135颗为研究组,同一患者对侧非埋伏阻生尖牙135颗为对照组。（1）采用NNT Viewer软件、Planmeca Dimaxis Pro软件分别对患者的CBCT图像和曲面体层片进行测量,将曲面体层片中上颌埋伏阻生尖牙近远中向位置分为5区（Ⅰ ~ Ⅴ区）,其唇腭侧位置由CBCT判定,分析两者相关性。（2）在曲面体层片中测量分析研究组与对照组牙冠及牙根的近远中向位置分布、牙轴倾斜度以及牙齿长度的差异。结果　（1）不同性别患者上颌埋伏阻生尖牙唇腭侧位置分布的差异有统计学意义（χ2 = 13.542,P = 0.001）。曲面体层片中上颌埋伏阻生尖牙牙根近远中向的区域定位与CBCT中相应阻生尖牙的唇腭侧位之间有显著相关性（r = 0. 225,P = 0.009）;但其牙冠间无相关性（r = 0.001,P = 0.991）。（2）两组尖牙牙冠及牙根近远中向位置分布差异有统计学意义（χ2值分别为219.263、68.447,均P < 0.001）。研究组较对照组尖牙牙齿长度短,牙轴倾斜度大（均P < 0.05）。结论　利用曲面体层片中上颌阻生尖牙牙根近远中向的区域定位可预测其唇腭侧位。在曲面体层片中牙根近远中向位置和牙齿长度的测量结果可用于预测上颌埋伏阻生尖牙的发生。     

上颌腭侧埋伏阻生尖牙 CBCT 导引下的牵引治疗

目的:探讨锥形束CT(CBCT)三维(3D)重建在上颌腭侧埋伏阻生尖牙牵引治疗中的指导作用。方法:对22例上颌尖牙(共26颗)腭侧埋伏阻生的青少年患者行CBCT检查。CBCT三维重建观察尖牙形态、腭侧埋伏状况,测量分析与邻近组织的位置关系及相邻切牙牙根吸收情况。结果:CBCT能够真实再现颌骨内埋伏的上颌尖牙。埋伏尖牙均近中倾斜,与平面平均成角61.1°±18.1°,近中异位分别为Ⅰ类埋伏尖牙8颗、Ⅱ类5颗、Ⅲ类3颗、Ⅳ类10颗。3颗相邻侧切牙及2颗中切牙因严重牙根吸收而拔除;26颗上颌腭侧埋伏尖牙均成功牵引至平面排入牙弓并建立正常咬合。结论:CBCT能立体再现上颌尖牙腭侧埋伏阻生特征及与邻近牙的关系等,对治疗方案的制定、开窗牵引具有指导作用,可提高疗效。     

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目的比较手术—正畸联合治疗唇侧和腭侧上颌埋伏阻生尖牙的临床疗效。方法对广东省深圳市宝安区人民医院口腔正畸门诊2004—2009年收治的60例埋伏阻生尖牙患者(均为单颗埋伏阻生尖牙患者,共60颗牙),根据全口曲面断层片和X线定位片分为唇侧组和腭侧组各30颗牙,通过手术开窗去除阻力骨、暴露部分牙冠、黏结正畸附件,在固定矫正技术的牵引下将埋伏阻生的尖牙纳入正常牙弓内。对比两组治疗的成功率和治疗所需的时间。结果治疗成功率唇侧组为80.0%,腭侧组为96.7%,两组比较差异有统计学意义(P<0.01)。术后正畸牵引的时间腭侧组为(9.2±3.2)个月,而唇侧组为(15.1±4.1)个月,明显长于腭侧组,两组比较差异亦有统计学意义(P<0.01)。结论经手术开窗正畸牵引,上颌埋伏阻生尖牙的成功率腭侧组大于唇侧组,牵引到位的时间腭侧组也较唇侧组短。     

上颌尖牙埋伏阻生患者上颌切牙牙齿宽度改变的研究

目的探讨中国人上颌切牙宽度与尖牙阻生是否存在内在的联系.方法选择103名上颌尖牙埋伏阻生患者,分为46名腭侧阻生组和57名唇侧阻生组.选择年龄、性别匹配,上颌尖牙正常萌出的患者60名,作为对照组.测量这些患者的上颌切牙近远中宽度,并进行统计学分析.结果尖牙阻生患者的左右侧中切牙及侧切牙的近远中宽度基本一致,无统计学差异.尖牙唇侧阻生患者的侧切牙宽度大于对照组,腭侧阻生患者的侧切牙宽度小于对照组,均有统计学差异.唇腭侧阻生患者的侧切牙宽度有显著性差异.结论尖牙埋伏阻生患者的上颌切牙宽度变化和尖牙阻生的位置有着高度的相关性.     

上颌尖牙埋伏阻生的临床分析

目的对上颌尖牙埋伏阻生的患病特点及治疗结果进行分析,以期为临床治疗上颌尖牙埋伏阻生提供参考数据。方法在北京大学口腔医学院·口腔医院正畸科门诊2001年1月至2005年1月期间诊治的10505例错(牙合)畸形患者中,经CT检查选出上颌尖牙埋伏阻生患者215例(汉族),共有埋伏阻生尖牙248颗。统计上颌尖牙埋伏阻生在正畸患者中所占比例,χ~2检验分别比较患者性别、唇腭侧阻生以及相应治疗情况的差异。结果上颌尖牙埋伏阻生在正畸门诊患者中约占2．05%,女性：男性为1．8∶1,唇侧：腭侧为2．1∶1。“外科手术暴露+正畸牵引”的方式在治疗中占主导地位。“外科手术拔除”的治疗方式在腭侧埋伏阻生尖牙中的应用多于唇侧,差异有统计学意义(P＜0.01)。结论本组患者上颌尖牙埋伏阻生以女性、唇侧多见,临床对唇腭侧尖牙埋伏阻生的治疗存在一定差异。     

上颌埋伏阻生尖牙与牙弓及腭部形态的相关性

埋伏阻生尖牙是临床上常见的牙齿畸形,多种因素可导致尖牙骨内移位形成颊、腭侧阻生.近年来,有研究发现埋伏阻生尖牙与上牙弓及腭部形态之间有密切联系,牙弓宽度、长度、腭穹隆深度及腭面积、腭体积均可能与埋伏阻生牙相关.对上颌形态的研究有助于在临床工作中对尖牙阻生进行早期诊断和干预,减少治疗并发症.本文就埋伏阻生尖牙相关的上牙弓...     

曲面断层片和锥形束CT对上颌阻生尖牙的定位分析

目的:通过对曲面断层片中上颌阻生尖牙近远中向和垂直向的影像学分区,判定其与锥形束CT (cone-beam computed tomography, CBCT)中相应尖牙唇腭侧位及相邻恒切牙根吸收之间的关系。方法:对68例患者的94颗上颌阻生尖牙进行曲面断层片的拍摄和CBCT扫描。将曲面断层片中上颌阻生尖牙近远中向牙尖所处的位置分为5区(Ⅰ区-Ⅴ区),将牙冠所处的垂直向高度分为3部分(牙冠段,根中段,根尖段),其唇腭侧位置和相邻恒切牙的根吸收情况则由CBCT判定。结果:曲面断层片中上颌阻生尖牙近远中向的区域定位与CBCT中相应阻生牙的唇腭侧位之间有显著相关(P＜0.001),唇侧阻生的尖牙常出现在曲面断层片中的Ⅰ、Ⅱ、Ⅲ区域,正中牙槽阻生的多在Ⅳ区域,腭侧阻生的常在Ⅴ区域,而垂直向的分段与之无显著相关。CBCT中相邻恒切牙的根吸收常发生在Ⅳ、Ⅴ区域和根中段、根尖段。曲面断层片中阻生尖牙近远中向和垂直向的区域划分均与CBCT中相邻恒切牙的根吸收之间有统计学意义(P＜0.05)结论:利用曲面断层片中上颌阻生尖牙近远中向的区域定位可以预测其唇腭侧位和相邻恒切牙的根吸收,垂直向的分段可用来判断相邻恒切牙的根吸收,而不可推测其唇腭侧阻生情况。     

替牙期62例上颌尖牙阻生儿童牙弓及腭部形态特征分析

目的:比较上颌尖牙阻生与无阻生儿童牙弓及腭部形态的差异,为上颌尖牙阻生早期识别和干预提供参考.方法:选择8～11岁[平均(9.82±1.04)岁]儿童62例,分为实验组(上颌尖牙阻生)和对照组(无上颌尖牙阻生),每组31例.将2组患者石膏模型通过3D激光扫描后转化为数字模型,测量牙弓宽度、牙弓长度、基骨宽度、腭部宽度、...     

上颌尖牙阻生的病因

牙齿阻生的病因,主要与牙弓长度不足有关。然而,腭向阻生的尖牙,其病因则不是这样。本文目的是通过对腭向阻生和唇向未萌尖牙病因的研究,分析牙弓长度和尖牙阻生之间的关系。作者对手术和正畸治疗的46个上颌未萌尖牙进行了观察,其中40个腭向阻生,6个唇向未萌出,比例为6.6∶1。牙弓长度测量分为四类:1.牙弓长度过大;2.牙弓长度足够;3.牙间隙不足;4.上颌基骨凹陷。1～2类表明有足够间隙,3～4类表明牙弓长度不足。腭向阻生的尖牙     

Space conditions and dental and occlusal features in patients with palatally impacted maxillary canines: an aetiological study

The aetiology of palatal canine impaction is unclear. The aim of this research was to investigate the occlusal features that could contribute to the aetiology of palatal maxillary canine impaction. The material consisted of the pre-treatment dental casts of 34 patients (27 female and seven male) with unilateral palatal canine impaction (impaction group). The average age of this group was 17.7 years (+/- 4.6). These were matched according to age, gender and type of malocclusion with a comparison group of pre-treatment dental casts from unaffected orthodontic patients. From the dental casts the following parameters were obtained: (1) dentoalveolar arch relationship, (2) missing or anomalous teeth, (3) the mesiodistal width of each maxillary tooth, (4) the upper arch perimeter, (5) the maxillary inter-premolar and inter-molar widths. The arch length-tooth size discrepancy was only calculated for subjects with no missing teeth. Palatal canine impaction occurred most frequently in subjects with a Class II division 2 malocclusion. There was an association between palatal canine impaction and anomalous lateral incisors (P = 0.01). The transverse arch dimension was significantly wider in the impaction group than in the comparison group (P < 0.01). There was no statistically significant difference in the mesiodistal width of maxillary teeth or in the arch length-tooth size discrepancy between the palatal canine impaction group and their matched comparisons (P > 0.05). These results suggest that the presence of an 'excess palatal width' and anomalous lateral incisor may contribute to the aetiology of palatal canine impaction.     

单侧上颌尖牙阻生对牙颌三维结构的影响

目的: 采用锥形束CT（CBCT）研究单侧尖牙阻生病例牙颌的三维结构特征,评估发生上颌尖牙阻生的相关风险因素,为正畸临床早期干预提供依据。方法: 选取30例单侧上颌尖牙阻生患者的CBCT,利用Romexis软件进行三维重建,测量、比较两侧牙颌三维结构特征指标,采用SPSS17.0软件包进行配对t检验和相关数据的回归分析。结果: 阻生侧尖牙和侧切牙倾斜度明显增大,尖牙牙冠更向近中、侧切牙向远中倾斜（P<0.001）;阻生侧尖牙体积更大、侧切牙体积更小（P<0.05）,当尖牙体积增大或侧切牙体积减小时,上颌尖牙的阻生概率增加;阻生侧牙弓弧形长度更短,牙弓宽度在尖牙区和前磨牙区更短（P<0.001）,而宽度在磨牙区无显著差异（P>0.05）,两侧牙弓长度在尖牙区、前磨牙区和磨牙区无显著差异（P>0.05）。结论: 上颌尖牙阻生伴随或导致同侧牙及牙槽骨三维方向发育异常,上颌尖牙阻生的严重程度与周围牙颌结构异常密切相关,提示上颌尖牙阻生可以早期预判、诊断,且可以实施有效的早期干预。     

Dental anomalies and clinical features in patients with maxillary canine impaction: A retrospective study

Objective:To analyze the prevalence, distribution, clinical features, and relationship with dental anomalies of maxillary canine impaction.Materials and Methods:The complete pretreatment records of 1674 orthodontic patients were examined. Subjects with maxillary impacted canines were divided into two study groups: a palatally displaced canine (PDC) group (114 patients) and a buccally displaced canine (BDC) group (37 patients). These were compared to a control group of 151 patients who were randomly selected from the initial sample without maxillary canine impaction. The significance of associations between canine impaction and dental and clinical features and anomalies was examined with the chi-square test.Results:PDC patients presented with normal overjet and facial profile and a lower degree of dental arch crowding in comparison to the control patients. PDC patients showed a higher prevalence of impaction of other teeth, dental aplasia, transposition, and peg-shaped maxillary lateral incisors (odds ratios 3.3, 2.6, 8.3, and 5.8, respectively).Conclusion:PDC was frequently the only orthodontic problem of patients. BDC group patients did not present with notable differences in clinical and dental features or dental anomalies compared to control subjects.     

Morphology of the maxillary lateral incisor in cases of unilateral impaction of the maxillary canine

Two groups of subjects who demonstrated unilateral maxillary canine impaction were examined, a Caucasian group and an Oriental group. It was found that there are significant differences between the groups for sex of patients seeking treatment, site of impaction (buccal/palatal), and arch form. The Oriental group was significantly more crowded in the canine area than the Caucasian group. In almost all cases the dimensions of the lateral incisor on the side of impaction were smaller than the non-impacted side, although five subjects from the Caucasian female sub-group did not conform to this pattern, and for the Oriental male sub-group the mesiodistal crown width was larger on the impacted side.     

骨性Ⅲ类错（牙合）牙弓、基骨弓宽度及协调性分析

目的 探讨骨性Ⅲ类错（牙合）患者牙弓、基骨弓宽度及二者协调性,为临床诊断和治疗提供理论依据.方法 选择骨性Ⅲ类错（牙合）患者33例为实验组,47例个别正常（牙合）为对照组,利用锥形束CT扫描颌面部,将扫描后图像导入Mimics10.01图像处理软件分别测量牙弓宽度、基骨弓宽度,并计算上下颌对应宽度之差,对测量结果进行独立样本t检验.结果 骨性Ⅲ类错（牙合）组上颌牙弓宽度与个别正常（牙合）组比较无显著性差异,但下颌牙弓宽度大于正常（牙合）,其中下颌第一磨牙处平均宽度正常（牙合）为（56.26±3.09）mm,骨型Ⅲ类患者为（57.78±3.22）mm,差异有统计学意义（P＜0.05）;骨性Ⅲ类错（（牙合）上颌基骨弓宽度测量值均小于对照组,其中在上颌第二前磨牙处正常（骀）为（59.11±5.97）mm,骨型Ⅲ类患者为（56.23±5.28）mm,有统计学差异（P＜0.05）,下颌基骨弓宽度均大于对照组,其中在前磨牙及第一磨牙处分别为（47.44±2.96）mm、（59.81±3.87）mm和（76.20±4.20）mm,与正常（牙合）相比差异显著（P＜0.05）.骨性Ⅲ类错（牙合）上下颌基骨弓宽度差值均小于正常（牙合）（P＜0.01）,而牙弓宽度差值仅在尖牙处差异显著（P＜0.05）,其余牙位测量项目无统计学差异.结论 ①骨性Ⅲ类错（牙合）组上颌基骨宽度发育不足,下颌基骨宽度发育过度.②骨性Ⅲ类错（牙合）的宽度不协调表现在基骨水平,牙弓对基骨弓宽度不调有代偿.     

Dental arch dimensions in patients with unilateral cleft lip and palate

In this investigation, dental arch dimensions during different ages were studied in 72 children with unilateral cleft of the lip, alveolar process, and palate and were compared with those of normal children. All the children with clefts were treated surgically by surgeons of the Lancaster Cleft Palate Clinic. The dental arch dimensions were studied with the use of dental casts during the time of full deciduous dentition (3 to 4 years of age), mixed dentition (8 to 9 years of age), and permanent dentition (12 years of age). The major findings were: (1) all maxillary interdental widths and lengths were significantly smaller than the normal dimensions at all ages, except for intermolar width at age 12 years; and (2) the mandibular arch dimensions seemed to be related to changes in the maxillary arch; however, the influence of surgical procedures in the maxillary arch is not reflected severely in mandibular arch dental position.     

大年龄未手术腭裂患者上颌牙弓形态发育的研究

目的：探讨影响上颌牙弓生长发育的因素。方法：对２０例未手术腭裂患者的牙颌模型进行测量,并与２０名正常成人作对照分析。结果：大年龄未手术腭裂患者与正常成人在尖牙区宽度存在显著性差异（Ｐ〈０．０５）。而上颌深度及后牙区的宽度无显著性差异（Ｐ〉０．０５）。结论：在腭裂组,畸形的存在主要是在切牙区及尖牙区,对后牙区横向和垂直向的影响较小。     

Maxillary sinus volume in patients with impacted canines

Objectives:To evaluate the maxillary sinus volumes in unilaterally impacted canine patients and to compare the volumetric changes that occur after the eruption of canines to the dental arch using cone beam computed tomography (CBCT).Materials and Methods:Pre- (T0) and posttreatment (T1) CBCT records of 30 patients were used to calculate maxillary sinus volumes between the impacted and erupted canine sides. The InVivoDental 5.0 program was used to measure the volume of the maxillary sinuses. The distance from impacted canine cusp tip to the target point on the palatal plane was also measured.Results:Right maxillary sinus volume was statistically significantly smaller compared to that of the left maxillary sinus when the canine was impacted on the right side at T0. According to the T1 measurements there was no significant difference between the mean volumes of the impaction side and the contralateral side. The distance from the canine tip to its target point on the palatal plane were 17.17 mm, and the distance from the tip to the target point was 15.14 mm for the left- and right-side impacted canines, respectively, and there was a significant difference between the mean amount of change of both sides of maxillary sinuses after treatment of impacted canines.Conclusions:Orthodontic treatment of impacted canines created a significant increase in maxillary sinus volume when the impacted canines were closer with respect to the maxillary sinus.     

Morphological relationship analysis of impacted maxillary canines and the adjacent teeth on 3-dimensional reconstructed CT images

Objective:To examine whether there is a relationship between maxillary canine impaction and the morphologic characteristics of the maxillary dentition, especially the root of the lateral incisor.Materials and Methods:In this study, we selected only patients with unilateral maxillary canine impaction to compare the morphologic characteristics of the dentition on the impaction side and the clinically normal eruption side. The sample size was decided to be 40 based on the pilot study. To minimize bias depending on sex and location of the maxillary canine impaction, we selected equal numbers (20) of boys and girls, and equal cases (20) of buccal impaction and palatal impaction. Under the aforementioned conditions, the mean age was 13.5 ± 2.3 years. The multislice spiral computed tomography images of these 40 subjects were converted into three-dimensional (3D) reconstructed images using the OnDemand 3D program (Cybermed Co, Seoul, Korea). Then we measured the morphologic characteristics of the individual teeth on the obtained 3D teeth images.Results:Length and volume of the maxillary lateral incisor''s roots were significantly smaller on the impaction side compared with the normal eruption side (P = 0.001 and P = 0.006, respectively). The width and volume of the canine''s crown were significantly greater on the impaction side compared with the normal eruption side (P = 0.020 and P < .0001, respectively).Conclusion:These results might help to prove the hypothesis that the smaller-sized lateral incisor roots and greater-sized canine crowns are the influential etiologic factors in maxillary canine impaction.