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。     

A survey of hypodontia in Japanese orthodontic patients.

INTRODUCTION: The purpose of this retrospective study was to assess the prevalence and distribution of hypodontia in the permanent dentition, excluding the third molars, in a sample of Japanese orthodontic patients. METHODS: Orthopantomograms of 3358 Japanese orthodontic patients (1453 boys and 1905 girls) between the ages of 5 and 15 years were examined for evidence of hypodontia. RESULTS: The prevalence of hypodontia was 8.5% (7.5% for boys, 9.3% for girls) with no statistically significant difference between the sexes. The average number of missing teeth per child was 2.4 (2.5 for boys, 2.4 for girls). Most (76.3%) children with hypodontia were missing either 1 or 2 teeth (77.1% for boys, 75.7% for girls). The prevalence of advanced hypodontia was 10.1% (11.0% for boys, 9.7% for girls). The most commonly missing teeth were the mandibular second premolars, followed by the mandibular and maxillary lateral incisors, and the maxillary second premolars; minor differences in the order of prevalence existed among groups of children classified by the number of missing teeth. Symmetrical hypodontia was predominant, and the most commonly symmetrical hypodontia was mandibular second premolar agenesis. No consistent finding was obtained as to which jaw had more missing teeth. The distribution of missing teeth was similar between the right and left sides of the dental arches in each group of children. Anterior tooth agenesis was predominant in children with minor hypodontia, and posterior tooth agenesis increased with hypodontia severity. CONCLUSIONS: The distinct characteristic of hypodontia in the Japanese population compared with other populations was a higher prevalence of both advanced hypodontia and mandibular lateral incisor agenesis in children with minor hypodontia.     

Trends in orthodontic management strategies for patients with congenitally missing lateral incisors and premolars

ObjectivesTo identify changes in orthodontic management strategies in patients with hypodontia seen in 2000, 2010, and 2017/2018 (during a 1-year period).Materials and MethodsAn assessment of the panoramic radiographs of 3701 patients from a Western Australian private practice identified 276 individuals demonstrating hypodontia. The location of missing teeth, age, sex, type of malocclusion, and the management strategies (space closure or opening) for each patient were noted.ResultsMost hypodontia involved agenesis of three or fewer teeth (90%). Maxillary lateral incisors and mandibular second premolars were the most commonly missing teeth. Female preponderance was noted. When considering treatment, the odds ratio for orthodontic space opening and prosthetic replacement in 2000 was 3.266 (P value = 7e-04; 95% confidence interval [CI], 1.464–4.633) compared with patients seen in 2010 and 1.632 (P value = 7e-04; 95% CI, 0.811–2.434) compared with patients in 2017/2018. For patients demonstrating bilateral absence of maxillary lateral incisors, the odds ratio for orthodontic space opening was 3.185 (P value = 0.0215; 95% CI, 1.182–9.243) compared with counterparts with unilateral agenesis. None of the factors investigated were significantly associated with the types of treatment planned/provided for the patients with missing mandibular second premolars.ConclusionsMaxillary lateral incisors and mandibular second premolars were the most commonly missing teeth. A trend away from space opening and prosthetic replacement toward orthodontic space closure was observed from 2000 to 2017/2018. This may reflect a change in attitude toward prosthetic replacement options and/or greater optimism with biomechanical strategies since the implementation of temporary anchorage devices to assist in space closure.     

Hypodontia in children with various types of clefts

The prevalence of hypodontia in children with clefts, both inside and outside the cleft region, and the possible association between the side of the cleft and the side of the missing teeth were studied using radiographs of 278 patients with cleft lip, cleft palate, or both (158 boys and 120 girls), age 5 to 18 years (mean age 10.4 years). A hypodontia prevalence of 77% (excluding third molars) was found for the total cleft sample. This was significantly higher, both statistically and clinically, than the incidence of hypodontia reported for noncleft populations, and considerably higher than the prevalence reported in other studies of children with clefts. The maxillary permanent lateral incisors were the teeth most frequently missing on the cleft side (259 teeth) followed by the maxillary (47 teeth) and mandibular (23 teeth) second premolars, in both boys and girls. The teeth that were most often missing on the noncleft side were the maxillary second premolars (12 teeth), followed by the maxillary lateral incisors (10 teeth) and mandibular second premolars (6 teeth). Hypodontia of both the maxillary lateral incisors and second premolars was found more frequently on the left side, which also has a higher frequency of clefting.     

Radiographic assessment of congenitally missing teeth in orthodontic patients

Summary. Objective. To estimate the prevalence of congenitally missing teeth (CMT) in patients evaluated for orthodontic care. A sample of 668 panoramic radiographs from Mexican population was reviewed from orthodontic healthy patients, 9–20 years old. Method. Statistical tests were used to compare maxillary and mandibular hypodontia in right and left quadrants between males and females. Results. Prevalence was 27% when all teeth were included, and was 2·7% when third molars were excluded. A significant difference was found between maxillary and mandibular symmetrical CMT in third maxillary molars, lateral incisors and second premolars (P < 0·001), and in mandibular third molars and central incisors (P < 0·001). Conclusions. We confirmed that occurrence of CMT in the permanent dentition of a Mexican population most often affects third molars, followed by maxillary lateral incisors and then mandibular second premolars.     

Hypodontia in 9-year-old Norwegians related to need of orthodontic treatment

The present study reports on the prevalence of hypodontia in a Norwegian population and classifies children with hypodontia according to need of orthodontic treatment. Orthopantomograms of 1953 children (960 girls and 993 boys) at the age of 9 were available for examination. Of the boys registered with hypodontia of second premolars at the age of 9, 11.3% showed late mineralization between the ages of 9 and 12. Only 2.9% of the girls showed late mineralization. The corrected prevalence of hypodontia, excluding third molars, in the girls was 7.2%, in the boys 5.8%, and in both sexes combined 6.5%, the difference between sexes not being statistically significant. Of the children with hypodontia, 86.6% lacked only one or two permanent teeth. The most frequently missing teeth were the mandibular second premolars, the maxillary second premolars, and the maxillary lateral incisors, in that order. Classification of children with hypodontia according to need of orthodontic treatment showed that about two-thirds had hypodontia only of single posterior teeth with a moderate need of treatment. About one-third had hypodontia involving anterior teeth, and only 3.1% had hypodontia of two or more teeth in the same quadrant with a great need of treatment.     

6453名17～21岁青年人恒牙发育异常的调查

目的调查青年人恒牙牙齿形态和数目异常的状况。方法2002至2004年对3所北京高校6453名17～21岁学生进行恒牙数目和形态异常的调查。对不同性别和不同牙位发育异常的患病率进行卡方检验，并对2种牙齿异常伴发的情况进行卡方检验。结果牙齿数目和形态异常的总患病率为16．07％。女性锥形牙或桶状牙、畸形中央尖和先天缺牙的患病率高于男性，差异有统计学意义（P〈0．05）。牙内陷、锥形牙或桶状牙好发于上颌侧切牙，畸形中央尖好发于下颌第二前磨牙，融合牙和先天缺牙好发于下颌切牙，差异均有统计学意义（P〈0．01）。锥形牙或桶状牙与先天缺牙伴发的比率高，差异有统计学意义（P〈0．01）。结论各种牙齿数目和形态异常的患病率、性别差异和好发牙位与以往的研究基本相符。但锥形牙或桶状牙、畸形中央尖的女性患病率均高于男性。     

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．     

Patterns of tooth agenesis in Japanese subjects with bilateral agenesis of mandibular second premolars

The aim of this study was to explore the patterns of tooth agenesis in Japanese orthodontic patients with bilateral agenesis of mandibular second premolars. A total of 80 Japanese orthodontic patients with 2 congenitally missing mandibular second premolars were selected as the subjects of this study (experimental group). Another 80 individuals without bilateral agenesis of mandibular second premolars were collected for comparison (control group). The 2 groups were matched with regard to sex. Radiographs, dental casts and records of medical and/or dental treatment were used to identify tooth agenesis. The Chi-square test, odds ratio, and test for equality were used to make statistical comparisons. The prevalence rates of other types of tooth agenesis were significantly higher in the experimental group than in the control group. The occurrence of agenesis of maxillary and mandibular lateral incisors and third molars, and maxillary second premolars was also significantly higher in the experimental group than in the control group. Significantly increased prevalence rates of symmetrical tooth agenesis, with third molars included, and oligodontia were observed in the experimental group. Japanese subjects with bilateral agenesis of mandibular second premolars are at significantly high risk of agenesis of other types of permanent teeth, symmetrical tooth agenesis and oligodontia.     

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.     

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 of permanent teeth in Danish schoolchildren

Hypodontia, congenitally missing teeth, is one of the conditions recorded during systematic orthodontic screening of groups of children attending a community child dental health service. The present investigation reports the prevalence of hypodontia in 3325 9–10-year-old children in the 3rd schoolgrade examined with an orthopantornographic radiograph. The prevalence of children with hypodontia was found to be 7.8%. Fifty percent of these children were missing only one tooth while 85% were missing either one or two teeth. More teeth were missing in the mandible than in the maxilla. The teeth most frequently missing were the second premolars, representing 67% of the congenitally missing teeth. Symmetrical hypodontia of second premolars occurred approximately twice as often in girls as in boys. Though more teeth were congenitally missing in girls than in boys, no difference could be seen in the prevalence of hypodontia in boys (7.7%) and girls (7.8%).     

Prevalence of hypodontia and malformations of permanent teeth in Iceland

This study was performed to elucidate the prevalence of hypodontia and congenital malformations of permanent teeth in Iceland. Computer analysis was done on the basis of results from examining 1,116 children (521 boys and 595 girls), or about 9.5% of all schoolchildren in Reykjavík in stages DS 3 (canines and premolars erupting) and DS 4 (canines and premolars fully erupted) of dental development at the time of the study. The age range was mainly from 8-16 years. The prevalence of congenitally missing teeth (second and third molars excluded) was 6.7% in boys and somewhat higher, 8.9%, in girls, 7.9% for both sexes combined. On the average, each child was missing 1.9 teeth. In the girls, the most commonly absent teeth were the mandibular second premolar (55%), the maxillary second premolar (19%), and the maxillary lateral incisors (18%). In the boys the figures were 51%, 18%, and 10%, respectively. Malformation of permanent teeth, mainly in the form of pegshaped maxillary laterals, was also less common in the boys, 1.3% against 3.0% in the girls, and 2.2% for both sexes combined. Among Icelandic children hypodontia and/or congenital malformation of permanent teeth were found in 9.1%.     

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。     

Tooth dimensions in hypodontia patients,their unaffected relatives and a control group measured by a new image analysis system

Tooth dimensions were compared between index patients with severe hypodontia (six or more congenitally missing teeth), their relatives with a full complement of teeth, and a control group. The groups consisted of 12 index cases (seven females and five males), 21 relatives without hypodontia (13 females and eight males), and a control group of 10 males and 10 females with complete dentitions, and no family history of hypodontia. All formed teeth were imaged buccally and occlusally from study models, with a digital camera linked to a computer. The images were acquired and measured using Adobe Photoshop and Image Pro Plus, respectively. Mesiodistal, buccolingual, or occlusogingival area and perimeter measurements were determined from each image. In the index hypodontia group tooth dimensions were significantly smaller (P < 0.001, Bonferroni corrected level) for maxillary and mandibular canines, and first premolars for all dimensions from the buccal view, and for maxillary and mandibular canines and first premolars, maxillary central incisors, maxillary first molars, mandibular lateral incisors, and mandibular second premolars for all dimensions from the occlusal view. In the relatives without hypodontia compared with the control group, mesiodistal dimensions from the buccal view were significantly smaller (P < 0.001) for the central incisors and maxillary first and second premolars, and for the maxillary and mandibular first premolars for all dimensions from the occlusal view. There was a trend for the tooth dimensions of all teeth in the index group to be smaller compared with the control group. The tooth dimensions of the relatives without hypodontia also tended to be smaller than the control group, but were larger than those of the index cases.     

Dental Findings in Patients with Ectodermal Dysplasia

BACKGROUND: Ectodermal dysplasia is an inherited disease causing malformations of all tissues originating from the ectoderm. The significance of this disease lies in severe hypodontia, and an accompanying hypoplasia of the alveolar process. The clinical situation is aggravated by a significant xerostomia. It was the aim of this study to document the distribution of hypodontia and tooth malformation. Furthermore, we aimed to elucidate the clinical impact of these findings. PATIENTS AND METHODS: Records of 30 patients (19 males, 11 females) suffering from ectodermal dysplasia were included. Their age ranged between 7 and 23 years. All patients had been examined clinically and radiographically. In every patient, a record was made of which teeth were missing or malformed, and which deciduous teeth persisted. Additionally, the entire treatment procedure was assessed. RESULTS: The third molars were missing in all of the patients. The number of aplastic permanent teeth ranged from 2 to 26. The maxillary lateral incisors were most frequently absent, followed by the mandibular central incisors. The most stable teeth were the central incisors of the upper jaw, and the canines and first molars in both jaws. However, the maxillary central incisors and canines were the teeth most affected by malformation. Deciduous canines and second molars were the most often persisting teeth due to agenesis of the maxillary lateral permanent incisors and mandibular second premolars. In two-thirds of the patients, missing teeth were replaced by removable dentures. Half of the patients received orthodontic treatment. CONCLUSIONS: Hypodontia and malformation are almost regular dental characteristics in patients suffering from ectodermal dysplasia. The distribution of absent teeth deviates remarkably from the general population. Treatment requires an interdisciplinary approach including orthodontics, prosthodontics and oral surgery.     

Clinical management of the congenitally missing maxillary lateral incisor and mandibular second premolar: a clinical perspective

The decision to close maintain, or open space at the agenesis sites of the maxillary lateral incisor and mandibular second premolar is generally based on several factors, including the class of malocclusion, skeletal pattern (divergence), esthetics, function, and periodontics. Replacement of congenitally missing maxillary lateral incisors, the second most commonly missing teeth, can involve (1) canine replacement, (2) tooth-supported restoration, and (3) implants. This paper contrary to the opinion of other authors, favors replacement of the congenitally missing lateral incisors in one of several ways, versus orthodontic space closure.     

Hypodontia patterns and variations in craniofacial morphology in Japanese orthodontic patients

OBJECTIVE: The purpose of this study was to explore the association of hypodontia patterns and variations in craniofacial morphology in Japanese orthodontic patients. MATERIALS AND METHODS: A total of 50 girls with hypodontia (the total group) were selected and categorized into anterior, posterior, and anterior-posterior groups according to the location of the congenitally missing teeth. By using the lateral cephalograms of each subject, 28 angular and 37 linear measurements were made. The cephalometric data were statistically analyzed and compared among the groups and with the Japanese cephalometric standards from 36 age-matched female subjects without hypodontia or malocclusion (the control group). RESULTS: Every hypodontia group showed shorter anterior and overall cranial base lengths, shorter maxillary length, greater retroclination and elongation of mandibular incisors, and a larger interincisal angle than the control group. The total and anterior-posterior groups especially exhibited a significantly more prognathic mandible, larger retroclination of maxillary incisors, and a more counterclockwise-rotated occlusal plane. Furthermore, these skeletal and dental deviations were more remarkable in the anterior-posterior group than in either the anterior or the posterior group. Anterior hypodontia exerted as much influence on craniofacial morphology as posterior hypodontia. CONCLUSIONS: When orthodontic treatment is performed on patients with hypodontia, not only the number but also the distribution of missing teeth should be taken into consideration, though there was no significant difference in craniofacial morphology between anterior hypodontia and posterior hypodontia.     

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目的调查分析大连地区正畸患者恒牙先天缺失的发生率及分布,包括第三磨牙。方法随机抽取2008年7月至2011年6月来大连市口腔医院就诊的正畸患者800例(男260例,女540例;年龄9～40岁),通过观察其全颌曲面断层片,分析恒牙先天缺失的发生率及分布。结果包括第三磨牙在内的恒牙先天缺失发生率为36.13%,除第三磨牙外的恒牙先天缺失发生率为12.5%。性别间差异无统计学意义(P>0.05)。除第三磨牙外的轻度先天缺牙例数(缺失1～2颗牙)占87%,中度先天缺牙例数(缺失3～5颗牙)占10%,重度先天缺牙例数(缺失牙≥6颗)占3%。常见的缺失牙位因缺牙程度的不同而不同,轻度缺失时,最常见的缺失牙位在前牙(最多见的是右下侧切牙),随着缺牙程度的加重,常见的缺失牙位在后牙(最常见的是下颌第二前磨牙)。上、下颌的缺牙情况是,轻度缺牙(缺失1～2颗)时,下颌的发生率高于上颌;中、重度缺牙时,上、下颌之间差异无统计学意义(P>0.05)。上、下牙弓左右侧的缺牙发生率差异无统计学意义(P>0.05)。缺失牙≥2颗时,对称缺失占大多数,最常见的对称缺失牙位是下颌第二前磨牙。结论除第三磨牙外,大连地区正畸患者最常见的缺失牙位是下颌侧切牙;随先天缺牙程度加重,则以下颌第二前磨牙先天缺失最常见。     

Prevalence of hypodontia and developmental malformation of permanent teeth in Saudi Arabian schoolchildren

This study was carried out to determine the prevalence of hypodontia and congenital malformation in permanent teeth of Saudi Arabian male children. Five-hundred schoolchildren were investigated, selected randomly from Riyadh city. The age group of the examined sample ranged from 13 years and 6 months to 14 years and 6 months. Clinical and radiographic examinations were performed. The findings indicated that hypodontia was present in about 4 per cent of the children; most frequently affected was the mandibular second premolars, maxillary laterals, and maxillary second premolars. Tooth malformations, mainly peg-shaped upper lateral incisors were also observed in about 4 per cent of the sample.