新疆维、汉大学生恒牙先天缺失情况的调查分析

目的 调查新疆维汉两民族青年人恒牙先天缺失的状况。方法 2008-2009年对新疆高校学生共5150名采取随机、整群抽样的方法 进行恒牙发育异常情况的调查。对总体及维汉两民族先天缺牙情况进行患病率、颌位情况、缺牙数目、好发牙位及同时伴发2种牙齿发育异常的情况进行卡方检验。结果 恒牙先天缺失的总患病率为5.98%,汉族高于维族(P<0.05),维族男性患病率低于女性(P<0.05)。总体及汉族缺牙数目下颌多于上颌(P<0.05),好发牙位为下颌中切牙;总体及维汉均以缺失1颗牙者最多见,且锥形牙与先天缺牙伴发的比率高。结论 恒牙先天缺失的总患病率略低于其他学者的研究,民族间患病率有差异,汉族高于维吾尔族。性别差异、颌位情况、缺牙数目、好发牙位及伴发情况与其他学者的研究基本一致。?     

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。     

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。     

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     

混合牙列期儿童的牙齿数目及形态异常的分析

目的 应用曲面断层技术分析混合牙列期儿童恒牙数目及形态异常的发生情况。方法 收集2011年9月—2013年9月就诊的5~15岁混合牙列期儿童的曲面断层片,共纳入4 347张,观察记录先天缺牙、多生牙、牙瘤、过小牙、融合牙、弯曲牙和畸形牙尖的发生情况。应用SPSS 16.0统计学软件分析所得数据。结果 牙齿数目及形态异常的患病率为31.79%（1 382/4 347）,男性多于女性,差异具有统计学意义（P<0.05）。先天缺牙为最常见的牙齿数目及形态异常,患病率为15.00%（652/4 347）,女性多见;其次为多生牙,患病率为12.61%（548/4 347）,男性多见（P<0.05）。过小牙、弯曲牙患病率分别为4.00%（174/4 347）和2.16%（94/4 347）,畸形牙尖、牙瘤、融合牙较少见,分别为0.74%（32/4 347）、0.51%（22/4 347）、0.39%（17/4 347）。结论 混合牙列期儿童恒牙数目及形态异常的患病率较高,先天缺牙和多生牙最常见。应用曲面断层技术进行检查,可早期发现牙齿发育异常。     

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。     

多个恒牙先天缺失的缺牙特点分析

目的比较分析严重恒牙先天缺失病例的缺牙特点,为临床工作提供参考。方法对37例多个恒牙(≥6个)先天缺失的病例按临床表现分为综合征型和单纯型先天缺牙两组,从恒牙先天缺失数目、牙位分布、余留牙畸形及牙齿大小等方面比较分析严重先天缺牙的表型特点。结果综合征型先天缺牙比单纯型先天缺牙在平均缺牙数目、现存牙齿合并畸形上都表现得更为严重(P<0.05);两组严重缺牙患者先天恒牙缺失的牙位分布在上下颌和左右侧之间均无差别(P>0.05),缺失牙位均呈对称分布,但最易缺失的牙位有所不同;严重先天缺牙患者现存恒牙牙冠宽度较正常值偏小(P<0.05)。结论多个恒牙先天缺失包含复杂的临床表现,综合征型与单纯型的严重先天缺牙在口腔缺牙特点上有明显差异,值得临床鉴别参考。     

非综合征型先天缺牙的研究进展

先天缺牙是人类牙列中最常见的发育异常，多为恒牙缺失，乳牙先天性缺失少见。可见为散发病例或家族遗传形式，后者可以是常染色体显性遗传、常染色体隐性遗传或X染色体遗传。先天缺牙根据是否有伴发症状，可分为：①单纯性或非综合征型先天缺牙，即仅有牙齿的先天缺失；②综合征型先天缺牙，即先天缺牙同时伴有其他器官的发育异常。根据缺牙数目可分为个别牙缺失、多数牙缺失和先天性无牙。多数牙缺失是指缺牙数目在6个及6个以上者（不包括第三磨牙）。     

先天缺牙与牙颌畸形

部份恒牙先天缺失是牙颌畸形常见先天病因之一。当先天缺牙并伴有其它某些局部、全身或遗传因素时,畸形可能更加复杂,给治疗带来一定的困难。有关先天缺牙问题,早在100多年前已有报告,其发生率为2.3～6.0%,可能缺失一个或多个乳牙或恒牙,缺失最多者为下颌第二双尖牙,其次为上颌侧切牙,上颌第二双尖牙,下颌中切牙。本文的目的是探讨     

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...     

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．     

An audit of concomitant dental anomalies with maxillary talon cusps in a group of children from Hong Kong

AIM: To investigate the prevalence of various concomitant dental anomalies in Hong Kong children with true talon cusps on the permanent maxillary incisors. METHODS: Dental records and radiographs of a group of Hong Kong Chinese primary schoolchildren with true talon cusps (half crown height or more) on one or more permanent maxillary incisors were selected and studied retrospectively. The prevalence of various dental anomalies in this group of children was compared with that of the general population of Hong Kong Chinese children of similar age. RESULTS: A total of 11,537 records were reviewed and 58 children with true talon cusps on one or more permanent maxillary incisors were identified. A total of 69 permanent maxillary incisors were affected, of which all except one were lateral incisors. Dens evaginatus on premolars, supernumerary teeth in the anterior maxilla, and hypodontia were found in 5 (8.6%), 5 (8.6%), and 5 (8.6%) cases respectively. The prevalence of supernumerary teeth was significantly higher in children with true talon cusps as compared with the results of two previous general studies of Chinese children of similar age (P<0.05, Fisher's exact test). CONCLUSION: Children with true talon cusps on the permanent maxillary incisors were more frequently affected by supernumerary teeth in the anterior maxilla. Further studies with a larger sample are needed to confirm a true association.     

Conservative treatment of dens evaginatus of anterior teeth

Abstract Dens evaginatus is a developmental malformation characterized by the presence of an extra cusp. In the anterior dentition, dens evaginatus is more commonly found in the maxilla and on the palatal surface of the tooth. Treatment may include root canal therapy followed by either an aesthetic restoration or a full crown coverage. In cases of mesiodens, supernumerary teeth or crowded dentition, extraction is often indicated. Presented is a case of a conservative treatment modality of dens evaginatus in a mandibular central incisor.     

A rare case of dens invaginatus in a mandibular canine

Dens invaginatus (dens in dente) is a common dental anomaly with a reported prevalence of between 0.04% and 10%. It typically affects permanent maxillary lateral incisors, central incisors and premolars. These developmental lesions are less common in mandibular teeth and are extremely rare in canines and molars. This report describes a rare case of dens invaginatus (Oehlers type II) in a permanent mandibular canine. The tooth was mature with a closed apex and showed apical pathosis. The tooth was treated endodontically using a non-surgical technique with hand endodontic files, and then followed up after a period of 8 months. A follow-up radiograph showed some healing of the lesion.     

Endodontic management of dens evaginatus of maxillary central incisors: a rare case report

Dens evaginatus is a disturbance in tooth development that produces a tubercle of hard tissue on the surface of the tooth. While prophylactic pulp capping is recommended for vital teeth, teeth with necrotic pulps require endodontic therapy or extraction. This rare case of a 24-yr-old Indian male with affected maxillary central incisors demonstrates the clinical consequences of dens evaginatus.     

Concurrent occurrence of dens evaginatus and dens invaginatus in maxillary incisors: a case report and review

Dens evaginatus (DE) and dens invaginatus (DI) are developmental anomalies that affect the shape of the teeth. Although they have been found singly and in association with other developmental anomalies in the same patient, it is uncommon to observe these two anomalies in the same tooth. There are only a few published cases of concurrent DI and DE in the same tooth. The patient in the case reported here was a 27-year-old man who exhibited a novel combination of DE and DI in permanent maxillary incisors. Early diagnosis of this anomaly is necessary. The clinician then can take particular care when performing prophylactic odontoplasty for the DE, keeping in mind that the associated DI presents an increased risk of early pulpal involvement. This article focuses on the management aspects of DE and DI.     

Diagnosis and clinical significance of dens invaginatus to practicing dentist

Dens invaginatus, commonly known as dens in dente, is a developmental malformation of teeth that most commonly affects permanent maxillary lateral incisors. Deciduous teeth are infrequently affected. Presence of dens invaginatus in mandibular permanent teeth is extremely uncommon. A rare presentation of coronal double dens invaginatus incidentally detected in a mandibular canine tooth on radiographic examination is being reported, along with a discussion of this anomaly. The patient had presented for routine dental treatment unrelated to this finding. In addition, the various radiographic appearances of dens invaginatus, as they present within the maxillary and mandibular teeth, are described. Essential clinical considerations and treatment options are presented. A review of the pertinent literature is undertaken, and tables summarizing previously published reports of mandibular dens invaginatus and double dens invaginatus are presented. A review of the literature indicates that dens invaginatus in mandibular teeth is extremely rare, with only 11 other cases, involving 14 teeth, reported previously. Cases of double dens invaginatus are even more atypical, with only eight previously reported cases. Dens invaginatus is an anomaly that should be familiar to all practicing dentists because of the clinical implications and potential sequelae.     

Dens evaginatus: case reports and review of the literature

Dens evaginatus is a developmental anomaly that produces a tubercle on the occlusal or palatal or lingual surfaces of teeth. The tubercle, which often contains pulp tissue, can cause occlusal interference, and pulpal pathology is a common sequel of attrition or fracture of the evagination. It affects a number of tooth types, but most commonly the premolar teeth of people of oriental ethnicity. Early diagnosis and management of dens evaginatus are important to maintain pulp vitality. This article describes three cases of dens evaginatus with different presentations.     

The prevalence of anterior teeth with dens invaginatus in the western mediterranean region of Turkey

Aim  To assess the prevalence and type of dens invaginatus in anterior teeth of a selected population and to report associated dental complications.
Methodology  The records of patients examined in the Department of Paedodontics, Faculty of Dentistry, Süleyman Demirel University, Isparta, Turkey between 1999 and 2006 were screened and a total of 2477 patients who had complete records with satisfactory radiographs were selected. The type of dens invaginatus and the presence of apical pathosis was determined from radiographs. Other dental abnormalities, syndromes and systemic diseases were noted. Variations in crown shape were also recorded.
Results  Dens invaginatus was detected in 300 out of 2477 patients, with a prevalence of 12%; 82% of affected patients had dens invaginatus bilaterally. Maxillary lateral incisors were the most affected teeth. The majority of the teeth had normal crown morphology (95%). The most commonly seen type of dens invaginatus was type I (94%). Overall 33% of the patients with type III dens invaginatus and 4% of the patients with type II dens invaginatus had apical pathosis. No associations with other systemic diseases and syndromes and some limited association with hypodontia and dens evaginatus were detected.
Conclusion  A carefull oral examination, radiographs, a suitable treatment plan and follow-up programme are crucial for early diagnosis and treatment for teeth with dens invaginatus.     

Combined endodontic and surgical management of a mandibular lateral incisor with a rare type of dens invaginatus

Dens invaginatus is a developmental malformation of teeth that most commonly affects permanent maxillary lateral incisors. Presence of dens invaginatus in mandibular permanent teeth is relatively rare. The purpose of this report is to describe the combined nonsurgical and surgical management of a mandibular lateral incisor associated with a rare type of dens invaginatus. Pulp involvement of the malformed tooth, periapical abscess, and severe periodontal destruction were observed. The signs (sinus tracts) and symptoms ceased after completion of the treatment. Satisfactory healing of the periradicular lesion was observed at the 6-month and 2-year follow-up examinations.