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．     

Epidemiologic study of idiopathic enamel hypomineralization in permanent teeth of Swedish children

In the late seventies an increasing number of children showing extensive and severe idiopathic hypomineralization of the enamel of incisors and permanent first molars was reported within the Public Dental Services in Sweden. An epidemiologic study was initiated to analyze the prevalence, extension and severity in Swedish children born in 1970 and in the years before and after. 2252 children born in 1966-74 were examined according to well defined criteria on enamel hypomineralization. It was found that 15.4% of the children born in 1970 showed such changes. The corresponding figures for children born in 1966, 1969, 1971, 1972 and 1974 were 6.3, 7.3, 7.1, 5.2 and 4.4, respectively.     

犬恒牙根管系统的解剖形态

目的:揭示犬恒牙列根管系统解剖形态的特点。方法:3只成年杂种犬处死后获取其全部126个恒牙(3副完整恒牙列)。经过抽真空法髓腔墨水染色、脱矿、脱水,最后将标本放入乙酰水杨酸甲酯溶液,制作成透明牙。结果:犬牙根管大多单根管,在根尖1～2 mm处发散出大量细小分支。结论:犬恒牙多为单根管但普遍存在着复杂的根尖分歧样结构。     

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。     

四川省6岁儿童乳恒牙患龋状况及相关性研究

目的了解四川省6岁儿童患龋情况,探讨乳磨牙患龋与第一恒磨牙患龋之间的相关性。方法参照第三次全国口腔健康流行病学抽样调查方案,在四川省3个城市、3个农村随机抽样选取调查点,共调查714名6岁儿童的患龋情况,并分析乳磨牙患龋情况与第一恒磨牙患龋情况之间的相关性。结果四川省6岁儿童乳牙患龋率为74.37%,龋均为3.94±3.93,龋齿充填率为4.96%。乳牙患龋率和龋均在男性和女性、城市和农村儿童间无统计学差异（P>0.05）,城市乳牙龋齿充填率高于农村（P<0.05）。已萌的第一恒磨牙中有2.98%患龋,充填率为7.69%。乳磨牙患龋是第一恒磨牙患龋的危险因素[P=0.001,r=0.175,OR=5.756,95%CI（1.733,19.121）],乳磨牙与第一恒磨牙的龋均呈弱相关（P<0.001,r=0.194）。结论四川省6岁儿童乳牙患龋情况较重,乳磨牙龋坏可作为临床及预防工作中预测第一恒磨牙龋坏的因素之一。     

Relationship between incisal tooth wear and the increasing number of permanent teeth in children and adolescents

summary The material presented in this report was derived from a longitudinal study of the development and progress of incisal tooth wear in children and adolescents. The study group was established in 1991/1992 and consisted of 77 participants between 8 and 15 years old. All participants were re-examined in 1994. The interval between the first and second examination was approximately 32 months. Each participant was scored for tooth wear of the anterior teeth of both jaws according to the Incisal wear Index (IwI) and the number of permanent teeth and the tooth types present were recorded at each examination. The results showed that the pattern of incisal wear had been maintained during the observation period. Severity of incisal wear increased as the number of teeth increased. The strength of the relationship between incisal wear and the number of teeth decreased during the observation period. At the same time, the number of teeth and the size of the wear increments were negatively correlated indicating that the rate of wear progression decreased as the number of teeth increased.     

Emergence of permanent teeth in Tanzanian children

OBJECTIVE: The aim of the present study was to investigate the emergence of permanent teeth among Tanzanian children. METHODS: A total of 869 Tanzanian children were recruited from 16 schools in age groups 3.5-5, 6.5-8, 9.5-11 and 15-16 years of whom 428 (49%) were boys and 441 (51%) were girls. The effects of age and gender on the emergence stages of the dentition were determined for the four age groups. RESULTS: Girls, but not boys, had some permanent maxillary canines, second premolars and mandibular and maxillary second molars as early as at the age of 6.5-8 years. Permanent teeth of both the first and the second transitional periods were already emerging at the age of 3.5-5 years and 6.5-8 years, respectively. At 3.5-5 years, 9% of the permanent teeth belonging to the first transitional period were already in occlusion. Emergence of incisors and first molars was more advanced in girls than in boys in age groups 3.5-5 and 6.5-8 years. CONCLUSIONS: Parallel to earlier reports on different ethnic groups, the results of this study indicate that the permanent teeth of Tanzanian children erupt earlier in girls than in boys, and the mandibular teeth erupt earlier than the corresponding maxillary teeth. The difference between boys and girls was found in both the first and second transitional period. Permanent teeth in Tanzanian children clearly emerge earlier than in Caucasian children.     

Eruption of permanent teeth in malnutrition children

The aim of this research was to study the eruption time of permanent teeth in malnutritional children of primary school Si Sa Ket province. The total sample size was 337, aged between 6-16 years. The results from the study showed that there were significantly delay in time of eruption of permanent teeth in malnutrition group when compared to the normal group of other study. The pattern of permanent dentition in malnutrition group coincided with those normal group of other study. There was high correlation between age and height, weight and eruption time of permanent teeth. Age estimation can be done through Regression equation based on eruption time of permanent teeth scores.     

Oral health in 5-year-old Swedish children

ABSTRACT The purpose of the study was to investigate the oral health of a group of 5-year-old children who had previously been examined in this respect at 3 and 4 years of age. The results were compared with those in an aged-matched reference group. The study included examination of caries and gingivitis, occlusion, presence of lactobacilli and C. albicans in plaque samples, flow rate, pH and buffer effect of stimulated saliva, and certain data on past prophylaxis and oral habits. Caries was found in 76 % of the children in the study group (S-group) and in 78% in the reference group (R-group). No significant differences were found in caries or gingival indices, in oral habits or prophylactic measures between the two groups. Buffer effect and pH of stimulated saliva were negatively correlated with deft and deft. Lactobacilli were demonstrated in 37 % and C. albicans in 12 % of the plaque samples. Various sucking habits were still present in 25 % of the S-group and 22 % of the R-group. Forty-nine and 46 % respectively had been given a daily supply of fluoride tablets by their parents for at least 2 years.     

Oral health in 4-year-old Swedish children

ABSTRACT The present study was carried out to investigate the oral status of a group of 4-year-old children who had already been investigated as 3-year-olds 1 year previously. The children were examined for caries, gingivitis, extrinsic stains, supragingival calculus, signs of traumatic injury, occlusion, interdental spacing, and lactobacilli and C. albicans in plaque samples. The parents were interviewed regarding toothbrushing habits, fluoride prophylaxis, and oral habits in the children. The investigation was performed in association with a general physical examination of the children. Caries was demonstrated in 67 % of the children. The mean Gingival Index was 0.52. Lactobacilli in plaque were detected in 34 % of the children and C. albicans in 18 %. The children in whom lactobacilli were demonstrated had significantly more decayed surfaces than the other children. Various sucking habits were noted in 42 % and nocturnal grinding of the teeth in 28%. Most of the parents had received dental advice at the Child Health Centers, and 41 % had given their children fluoride tablets regularly for at least 2 years.     

The emergence of permanent teeth in Flemish children

The aim of the present study was to investigate the timing of emergence of permanent teeth in Flanders (Belgium). Data were obtained in the Signal-Tandmobiel projecta, a longitudinal study in a sample of 4468 Flemish children. Survival analysis with a log-logistic distribution was performed to calculate median (and mean) values and 95% CI's for all permanent teeth. The analysis indicated significantly earlier emergence ages in girls than in boys. The emergence pattern turned out to be symmetric in both sexes. Most mandibular teeth emerged significantly before their antagonists, in boys as well as in girls. These findings are in agreement with other studies on the emergence of permanent teeth.     

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。     

Mottled permanent incisors in 15-year-old Lagos children

Mottled permanent incisors were studied in a stratified convenience sample of 206 Lagos schoolchildren aged 15 years. The mouth prevalence of this condition was 32%, and the right-left symmetry of the mottled incisors occurred very approximately in only a third of those persons with mottling. The distribution pattern was similar to that observed in similarly aged children in non-fluoride communities, and also that observed in optimally fluoridated Anglesey, England. The cause of this type of mottling in unknown, but its distribution suggests that endogenous (possibly genetic) factors may be involved.