邯郸市1895名大学生先天性缺牙的临床特征分析

目的了解河北邯郸市在校大学生恒牙先天性缺失的临床特征。方法随机对邯郸1895名大学生进行恒牙先天缺失临床特征的调查,并对先天缺牙患病率、数目及好发牙位等进行统计分析。结果恒牙先天缺失的总患病率为6.96%,男55例,女76例,性别间无统计学意义(P>0.05);下颌先天缺牙多于上颌(P<0.05);好发牙位为下颌中切牙;以缺1颗牙者最多见,占总人数的62.12%。患者缺牙伴有食物嵌塞者67.42%、邻面龋及继发病变者53.79%、牙合创伤者49.24%、牙周病者31.82%、咬合异常者61.36%。结论邯郸市在校大学生恒牙先天缺失多为少数缺牙,且性别间无统计学意义,下颌缺失牙数多于上颌,先天缺牙影响口腔健康及咬合关系。     

单纯型恒牙先天缺失患者缺牙特点的临床分析

目的了解单纯型恒牙先天缺失患者的缺牙牙位和临床统计学特点。方法收集183例单纯型恒牙先天缺失患者的病史、口腔检查及曲面断层X线片等资料，分类进行统计学分析。结果牙齿缺失数目、性别差异无统计学意义（P〉0.05）；上下颌、左右侧之间牙齿缺失差异无统计学意义（P〉0.05）；最易缺失的牙齿为下颌第二前磨牙，共缺失154颗；多数牙缺失患者磨牙缺失率为25.00％，较个别牙缺失患者磨牙缺失率（3．05％）明显增高，差异有统计学意义（P〈0．05）。结论不同患者恒牙缺失的临床表现不同；单纯型恒牙先天缺失患者中，除第三磨牙外，最易缺失的牙齿是下颌第二前磨牙，其次是下颌切牙、上颌第二前磨牙及上颌侧切牙     

乌鲁木齐地区青少年恒牙形态及数目异常的分析

目的探讨乌鲁木齐地区青少年先天缺失牙、多生牙、过小牙的发生率及好发部位。方法本文观察和分析了620例患者的全颌曲面体层X线片．均无恒牙拔牙史或牙齿损伤史。结果先天缺失牙（包括第三磨牙）的发生率为45．48％,第三磨牙的缺失发生率为32．58％,缺失牙的好发部位依次为上颌第三磨牙、下颌第三磨牙、下颌侧切牙、下颌中切牙、上颌第二双尖牙等;多生牙发生率为2．58％,好发部位是上颌切牙区。过小牙的发生率为6．30％．其主要为上颌侧切牙。结论牙齿先天缺失在人群中的发生率明显高于多生牙．缺失牙主要发生在功能相对弱的牙位上：缺失牙与过小牙之间存在一定联系．     

乳牙先天缺失及其继承恒牙表型的分析

目的 应用曲面断层技术研究乳牙先天缺失的特点及其继承恒牙的表现类型。方法 收集2020年1月—2021年12月就诊的3～6岁乳牙列期儿童的曲面体层片,共纳入15 749张,观察记录乳牙先天缺失的发生情况,同时记录其继承恒牙是否存在异常。应用SPSS 24.0统计软件分析所得的数据。结果 乳牙先天缺失的发生率为2.54%(400/15 749),女性217例多于男性183例,性别间差异有统计学意义（P=0.003）;乳牙先天缺失1～2颗例数占99.75%(399/400);下颌乳侧切牙先天缺失颗数占92.63%(490/529);左侧乳牙先天缺失颗数占44.80%(237/529),右侧乳牙先天缺失颗数占55.20%(292/529),两者差异有统计学意义（P=0.017）。上颌乳牙先天缺失颗数占3.59%(19/529),下颌乳牙先天缺失颗数占96.41%(510/529),两者差异有统计学意义（P=0.000）;单侧乳牙缺失占68.00%(272/400),双侧乳牙缺失占32.00%(128/400),两者差异有统计学意义（P=0.000）。乳牙先天缺失其继承恒牙有4种表型：1）继承...     

800例正畸患者中先天缺失牙及其与多生牙、锥形牙相关性分析

目的：观察正畸患者中伴有恒牙先天缺失、多生牙和锥形牙或过小牙的发生率及分布,并分析其相关性。方法：随机抽取正畸患者800例,男260例,女540例,年龄12-40岁。通过石膏模型和曲面断层片统计先天缺牙、多生牙、锥形牙或过小牙的发生率及分布。通过分类变量的关联性来分析多生牙和锥形牙或过小牙与先天缺牙的相关性,假设检验采用列联表的独立性x2检验,并采用Pearson列联系数r来描述两变量关联程度。结果：800例中发生恒牙先天缺失100例,发生率为12．5％。常见的缺失牙位从多到少依次为下颌侧切牙、下颌第二前磨牙、下颌中切牙、上颌侧切牙、上颌第二前磨牙。多生牙的发生率为3．1％,锥形牙或过小牙占8．3％。通过分类变量的关联性分析得出,锥形牙或过小牙的发生与先天缺牙有相关性,Pearson列联系数r为0．173。结论：正畸患者中恒牙先天缺失的发生率为12．5％,最常见的缺失牙位是下颌侧切牙和下颌第二前磨牙;正畸患者中恒牙先天缺失和锥形牙或过小牙的发生具有相关性。     

36例下切牙先天缺失正畸治疗的临床体会

目的探讨下切牙先天缺失的矫治设计。方法以伴有下切牙先天缺失的36例错畸形患者为研究对象,对下切牙缺失的部位、数目、错类型、矫治方法进行分析,并对缺失1颗下中切牙、拔除上颌2颗第一前磨牙和下颌1颗非缺牙侧第一前磨牙的病例及缺失2颗下中切牙、拔除上颌2颗第一前磨牙的病例的Bolton指数分析进行统计学检验。结果36例患者正畸治疗后均取得了较好的疗效。两组拔牙病例之间的Bolton指数全牙比无统计学差异（P>0.05）,而前牙比和前牙不调量有统计学差异（P<0.01）。结论先天缺1颗下中切牙上下颌均需拔牙者,在下颌非缺牙侧选择拔1颗前磨牙比拔1颗中切牙对Bolton指数影响要小     

非综合征型多数恒牙先天缺失的临床表型研究

目的 研究和分析非综合征型多数恒牙先天缺失患者的牙齿缺失特征,为该类患者的临床诊断、治疗设计提供参考。方法 收集178例非综合征型多数恒牙先天缺失病例,根据病史、口腔检查和曲面体层片等资料,研究分析牙齿缺失特征,应用SPSS 24.0统计软件对所得数据进行统计学分析。结果 缺牙数目在性别、左右侧间无明显差异,上颌缺牙数明显高于下颌（P<0.05）。缺失率最高的牙位是下颌第二前磨牙。上颌最常见的缺牙模式为双侧上颌第一前磨牙、第二前磨牙联合缺失,下颌为双侧下颌第二前磨牙联合缺失。左右侧对称性分布的缺牙模式高于上下颌对称性分布。16.85%患者同时合并其他牙齿发育畸形。结论 非综合征型多数恒牙先天缺失患者存在数种常见的缺牙模式,而咬合和全口缺牙模式变异较大,临床上应根据个体差异制定个性化的、多学科合作的治疗方案。     

锥形束CT诊断上颌前牙区多生牙价值研究

目的回顾性分析锥形束CT（CBCT）在上颌前牙区多生牙诊断及定位中的价值。方法以经CBCT确诊为上颌前牙区多生牙的146例患者的195颗多生牙为研究对象,分析多生牙的数目、形态、大小、空间位置、生长方向及其与邻近组织的关系。结果146例患者年龄5~39岁,男女比例为2.95∶1, 其中102例（69.9%）为单颗多生牙。195
颗多生牙的长度平均为（11.97±2.40）mm,其中,126颗（64.6%）位于中线区,131颗（67.2%）为圆锥形,51颗（26.2%）牙根弯曲,98颗（50.3%）牙冠生长方向倒置,133颗（68.2%）与邻近恒牙或恒牙胚有接触,恒牙牙列常伴有各种异常。结论多生牙空间位置变异大,可引起恒牙列病变。CBCT检查能精确直观地显示上颌前牙区多生牙及其与周围组织关系,对多生牙的诊断及定位具有重要的指导意义。     

7颗先天恒牙缺失伴多生牙1例

牙齿数目不足又称先天缺牙,是指牙胚发育过程中未能形成的牙齿. 先天缺牙可分为个别牙缺失、多数牙缺失和先天无牙症. 多数牙缺失指先天性缺失 6颗及以上牙齿(不包括第三磨牙),通常伴发系统性异常或是某综合征的部分表现. 临床上先天缺失 6 颗及以上的患者较少见,同时还伴有多生牙的病例比较罕见. 现报道 7 颗先天恒牙缺失伴...     

石家庄地区正畸患者恒牙先天缺失的调查分析

目的调查分析石家庄地区正畸患者恒牙先天缺失的发病率及特征。方法对河北医科大学口腔医院正畸科2010~2012年正畸患者中3274名有效病例的病历资料进行回顾分析。通过观察其全颌曲面断层片,分析恒牙先天缺失的发病率及分布差异。结果除第三磨牙外恒牙先天缺失的发病率为9.13,性别间差异无统计学意义（P〉0.05）。个别缺牙例数（缺牙数〈6）占总缺牙例数的95,其中缺失1~2颗牙的例数占总缺牙例数的88.6;多数缺牙例数（缺牙数≥6）占总缺牙例数的5。前、后牙区的缺牙发病情况在缺失1~2颗牙时,主要发生在前牙区,缺失2颗以上时,后牙区的缺失发病率高于前牙区（P〈0.05）;下颌缺牙发病率高于上颌（P〈0.05）。缺牙频率最高的是下颌侧切牙（25.3）,其次是下颌第二前磨牙（18.3）。结论石家庄地区正畸患者恒牙先天缺失（不包括第三磨牙）发病率为9.13,。其中以缺失1~2颗牙最常见,恒牙先天缺失更多的发生在前牙区及下颌,最常见的缺失牙位是下颌侧切牙和下颌第二前磨牙。     

Prevalence of numeric anomalies in the permanent dentition of patients with Down syndrome

The purpose of this study was to evaluate the prevalence of numeric anomalies in the permanent dentition of patients with Down syndrome by means of panoramic radiographs. The sample consisted of panoramic radiographs from 70 subjects. We examiend the radiographs to detect hypodontia as well as supernumerary teeth. Our results confirm the high prevalence of hypodontia among patients with Down syndrome (60%), mostly with mild expression. The teeth most often missing were the upper lateral incisors, usually bilaterally, followed by the lower second premolars and upper second premolars. Supernumerary teeth were seen in 6% of the subjects, and the concomitant occurrence of hypodontia and supernumerary teeth occurred in one patient.     

Hypodontia and hyperdontia of permanent teeth in Hong Kong schoolchildren

This study was performed to determine the prevalence of hypodontia and hyperdontia of permanent teeth amongst Southern Chinese children in Hong Kong. The sample consisted of 1093 12-yr-old children on whom a panoramic radiograph was taken. The prevalence of congenitally missing teeth (third molars excluded) was 6.1% in boys, 7.7% in girls, and 6.9% for both sexes combined. On the average, each child was missing 1.5 teeth. The most commonly absent tooth was the mandibular incisor, affecting 58.7% of the children with hypodontia. Thirty children (2.7%) had supernumerary teeth, with a male:female ratio of 6.5:1; in four cases the tooth had erupted. Three children had fourth molars and one case of a supplemental premolar was recorded (all unerupted). Four cases of a maxillary supernumerary tooth and hypodontia in the mandible were seen.     

Hypohyperdontia: Agenesis of three third molars and mandibular centrals associated with midline supernumerary tooth in mandible

Agenesis of teeth in a patient who also presents with a supernumerary tooth is one of the rare numerical anomalies in human dentition. Agenesis of third molars was shown to be associated with other missing permanent teeth. A review of literature on hypodontia including third molar agenesis, hyperdontia and a concomitant presence of these two conditions which is termed as hypohyperdontia is presented along with a case showing agenesis of three third molars, both mandibular central incisors and a midline supernumerary tooth.     

非综合征性单侧完全性唇腭裂恒牙发育异常的研究

目的 经回顾性研究了解非综合征性单侧完全性唇腭裂患者恒牙发育异常的情况.方法 收集244例植骨期非综合征性单侧完全性唇腭裂患者的影像学资料,记录和统计分析恒牙发育异常.结果 在本研究中各种恒牙异常的发生率为:先天缺失163例(269颗)(163/244,66.8%),最常累及的牙位是上颌侧切牙;畸形牙82例(85颗)(82/244,33.6%),绝大多数为上颌侧切牙的小牙畸形;额外牙12例(12颗)(12/244,4.9%),多发生于裂区,表现为畸形小牙.牙位发育异常的性别比较发现,非裂侧上颌仅侧切牙缺失,男性高于女性(P<0.05).裂侧的先天缺牙、额外牙和畸形牙的发生率均高于非裂侧,差异有统计学意义(P<0.01),上下颌均有相同发现.结论 非综合征性单侧完全性唇腭裂患者各类牙齿发育异常的患病率均高于健康人群.裂侧的牙齿发育异常较非裂侧更为多见.

Abstract：

Objective To investigate the prevalence of dentM anomalies in Chinese children with complete unilateral cleft lip and palate(UCLP).Methods Dental histories and radiographs of 244 Chinese children with UCLP were collected.The diagnosis of dental anomalies waft based on panoramic radiographs before alveolar bone grafting.All patients were over 8 years old.Results In the UCLP group,66.8% of the patients was presented with hypodontia.The maxillary lateral incisors were the most common teeth affected,followed by maxillary second premolars,mandibular incisors and mandibulax second premolars.A total of 33.6%the patients Was presented with dental malformation,most were mierodontic laterel incisors.A total of 4.9% the patients was presented with hyperdontim The supernumerary teeth were more frequently found in the cleft region.The prevalence of missing maxillary lateral incisor in the noneleft side was statistically different between genders,which was higher in male(P<0.050).This group of Chinese children with UCLP demonstrated significantly higher prevalence of hypodontia,hyperdontia,and malformation on the cleft side than on the noncleft side(P<0.01).Conclusions Hypodontia is the most common type of dental anomalies.The prevalence of dental anomalies is higher in the UCLP patients than in the normal population.Dental anomalies occur more frequently on the cleft side than on the nonclefi side.     

The prevalence of congenitally missing permanent teeth in Japanese children: A survey conducted in south-west area of Kanto district

AimThe purpose of this study was to investigate the prevalence of congenitally missing permanent teeth in Japanese children residing in south-west area of Kanto district in recent years.MethodsPanoramic radiographs taken for dental treatment between 1990 and 2007 were used to evaluate the congenitally missing permanent teeth excluding the third molar. The participants of this study consisted of 2,125 children aged between 7 and 20 years.ResultsThe congenitally missing teeth were observed in 251 participants (11.8%). The majority of the participants (114) presented with only one tooth missing, and there was a general tendency that the number of participants gradually decreased as the number of missing teeth increased. A total of 539 teeth were congenitally missing, and mandibular second premolar was the most frequently missing tooth (153 teeth), followed by mandibular lateral incisor (86 teeth), maxillary second premolar (71 teeth), maxillary lateral incisor (61 teeth). Only one missing tooth (114 participants) was found most frequently in mandibular lateral incisor (30 participants), followed by mandibular second premolar (28 participants). There was a tendency that congenitally missing teeth occurred symmetrically; especially most of the participants who had two missing teeth (80 in 88 participants) were symmetrically missing.ConclusionThe prevalence of congenitally missing permanent teeth in this study was 11.8% and it was comparable to those reported in previous studies of Japanese population evaluated using panoramic radiographs.     

Radiographic Features of Mandibular Trabecular Bone Structure in Hypodontia

Purpose: Radiographic parameters of mandibular trabecular bone structure between 67 subjects having hypodontia and those without were studied on digital panoramic radiographs. Materials and Methods: Three regions of interest (ROI) were defined: the ascending ramus, apical of the mandibular molar and mesial of the first mandibular molar. The effects of the presence of hypodontia and the ROI on the mandibular trabecular bone structure were tested for statistical significance by means of multivariate analysis. Results: Radiographic parameters of trabecular bone architecture were found to differ between various regions of the mandible (p = 0.000), but not between the group of hypodontia subjects and their controls (p = 0.23). There was no interaction effect between the ROIs and the two groups (p = 0.79). For people having hypodontia, some directional parameters of trabecular bone have a reverse correlation with the number of missing teeth. The fractal dimension and the number and perimeter of white segments in the binarized image correlate positively with the number of congenitally missing teeth. Conclusions: A limited number of parameters of radiographic mandibular trabecular bone structure correlate with the number of missing teeth. However, a markable difference in radiographic parameters of mandibular trabecular bone structure between hypodontia and non‐hypodontia subjects could not be demonstrated.     

A radiographic study of tooth development in hypodontia

OBJECTIVE: To investigate the radiographic development of permanent teeth in a group of children (66 females and 69 males, aged 3.08-15.02 years) with agenesis of one or more permanent teeth compared to a matched group. DESIGN: Tooth formation of all developing permanent teeth was assessed using Haavikko's method (1970) from dental panoramic tomographs. The difference between dental and chronological age was tested using a paired t-test. The correlation between the difference of dental and chronological age and severity of hypodontia was investigated using Spearman correlation test. In addition, radiographs of all children with only one single missing tooth in one quadrant and no more than two agenesis in total (N=59), were analyzed using the non-parametric Wilcoxon sign test, in order to investigate if the development of the teeth adjacent to the site of the agenesis was effected. RESULTS: Tooth formation in children with hypodontia was significantly delayed compared to the matched group (p<0.001). The mean difference was 1.51 years (S.D. 1.37 years). The severity of the hypodontia effected the magnitude of the delay (p<0.01). The teeth adjacent to the site of the agenesis were significantly delayed compared to the corresponding teeth in the matched group (p<0.01). CONCLUSION: These results confirm that the development of permanent teeth in children with hypodontia is different when compared with a matched group.