Examination of craniofacial morphology in Japanese patients with congenitally missing teeth: a cross-sectional study.

BACKGROUND: The purpose of this cross-sectional study was to investigate the effects of congenitally missing teeth on craniofacial morphology and to characterize the features of maxillofacial morphology of oligodontia patients associated with individual skeletal maturity by assessment with the cervical vertebrae maturation (CVM) method. METHODS: A total of 106 non-syndromic Japanese patients with congenitally missing teeth (except for third molars) were selected and categorized into two groups according to the severity of congenitally missing teeth (hypodontia group, 1-5 missing teeth [n = 56]; oligodontia group, ≥ 6 missing teeth [n = 50]). A control group included orthodontic patients without either skeletal disharmony or congenitally missing teeth (n = 63). Subjects in oligodontia and control groups were further categorized into two subgroups on the basis of cervical stage (CS): stage I (CS2 or 3; n = 27 and n = 31, respectively) and stage II (CS4 or above; n = 23 and n = 32, respectively). Lateral cephalograms were analyzed by using eight angular and eight linear measurements. Z-scores were formulated on the basis of age and sex and were matched to the Japanese norm. Tukey tests and t tests were performed. RESULTS: Compared with the control group, the hypodontia group had significantly smaller U1 to FH plane angle and A-B plane angle; U1-L1 was significantly larger. The oligodontia group had significantly smaller ANS-Me, L1 to mandibular plane angle, and Ptm-A; U1-L1 was significantly larger. At stage I, the oligodontia group had significantly smaller ANS-Me, gonial angle, and ANS-U1. At stage II, the oligodontia group had significantly smaller U1 to FH plane angle, L1 to mandibular plane angle, Ptm-A, and Go-Pog; it also had significantly larger U1-L1. CONCLUSIONS: The present study suggested that skeletal patterns differ along with the number of congenitally missing teeth and that, in oligodontia patients, skeletal patterns differ before and after growth peak. It is important to consider the skeletal characteristics of tooth agenesis patients when designing a treatment plan.

Nonsyndromic cleft lip and palate, gastric cancer and tooth agenesis

Background: To determine the frequency of nonsyndromic cleft lip and/or palate (NSCL/P) in first-degree relatives and to analyze the prevalence of tooth agenesis in patients with gastric cancer. Material and Methods: This cross-sectional, observational, case-control study included 798 patients attended at hospital Santa Casa in Montes Claros, Minas Gerais and Alfa Institute of Gastroenterology of the Federal University of the Minas Gerais. Information on basic demographic data and tooth agenesis of both groups and their family history of NSCL/P in first-degree relatives were evaluated. The collected information was stored in a database and analyzed using statistical program SPSS® version 21.0 and the values with p<0.05 were considered statistically significant. Results: Of the 798 patients, 113 (14.16%) consisted of the case group and 685 of the control group (85.84%). Non-Caucasian males were the most affected, although no differences among the groups were detected. Of all participants (n=798), 66 (8.27%) presented tooth agenesis and 25 (3.13%) presented oral cleft in first degree relative. Conclusions: Our results no found increase in the frequency of tooth agenesis in patients with gastric cancer and in the frequency of NSCL/P in the first-degree relatives of patients with gastric cancer (AU)

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Association between severity of hypodontia and cephalometric skeletal patterns: a retrospective study.

Objective: To assess if severity of hypodontia is related to a specific skeletal pattern. Study design: Lateral cephalometric radiographs and dental panoramic tomographs of 182 hypodontia patients were analysed. The severity of hypodontia was recorded and the sample was divided into groups with mild (n = 71), moderate (n = 56) and severe (n = 55) hypodontia. According to ethnicity, the sample was further subdivided into White Caucasians, African-British, and Arabian/Indian subgroups. Cephalometric measurements were used to quantify the skeletal discrepancy and vertical facial dimensions. Mean and standard deviation for each group were obtained for comparison and an analysis of variance (ANOVA) was carried out to assess the level of significance between the means of the readings in different severity groups. Results: In the white Caucasian group, increased severity of hypodontia, was related to a retrusive maxilla with concomitant reduction of A point, Nasion, B point (ANB), reduced mandibular plane angle and anterior lower facial height (P value: 0.0935-0.9371). For the Black-British and Arabian/Indian groups' findings were inconsistent, with no specific pattern as the number of missing teeth increased. Conclusion: The white Caucasian group followed a pattern that has previously been reported in other studies. For Black-British and Arabian/Indian groups' findings were inconsistent and no specific pattern emerged for different degrees of hypodontia.

The prevalence of dental anomalies in an Australian population.

BACKGROUND: The aim of this study was to determine the prevalence of dental anomalies within an Australian paediatric population using panoramic radiographs. METHODS: This was a prospective review of 1050 panoramic radiographs obtained as part of a school dental screening program in suburban and rural New South Wales, Australia. RESULTS: Fifty-four (5.14%) patients had a dental anomaly present. Agenesis was noted to have occurred 69 times across 45 patients (4.28%), along with seven cases of impaction (0.6%) and three cases of supernumerary teeth (0.28%). CONCLUSIONS: Dental anomalies rarely occur in the Australian population, which possesses a wide-ranging multiethnic cohort. Despite their rarity, they can be incidentally discovered so identification and management by dental practitioners are important.

Meta-analysis of congenitally missing teeth in the permanent dentition: Prevalence, variations across ethnicities, regions and time.

BACKGROUND: Congenitally missing teeth (CMT) are of concern to many fields of dentistry. Only a few reviews have been published in this regard. AIM: The aim was to analyze the literature on CMT in the permanent dentition, excluding the third molars, and to identify potential links with ethnicity, geographical regions, and time. METHODS: A total of 118 reports on CMT were collected by two authors by interrogating databases. Sample homogeneity, publication bias, publication year (in Caucasian and Mongoloid samples, and in general), ethnicities, and geography of CMT prevalence were statistically analyzed using a Q-test, Egger regression, linear regression, a Spearman coefficient, Kruskal-Wallis, a Dunn post-hoc (α = 0.05), and a Mann-Whitney U test (α = 0.0125, α = 0.0071). RESULTS: The mean CMT prevalence was 6.53% ± 3.33%. There were significant geographic differences in CMT rates (P = 0.0001, Kruskal-Wallis) and between ethnicities (P = 0.0002, Kruskal-Wallis). According to the Mann-Whitney U test (α = 0.0071), eastern Asians (P = 0.0008) and Europeans (marginally significant, P = 0.0128) showed an elevated prevalence, while Western Asians (P = 0.0001) and Americans (marginally significant, P = 0.0292) had lower prevalence rates. Compared with other ethnicities, Mongoloids showed higher prevalence (P = 0.0009) while Asian Caucasians showed lower rates (P = 0.0005, Mann-Whitney U, α = 0.0125). The year of publication was not significantly correlated with any of the subsamples studied (P > 0.3, linear regression). CONCLUSIONS: Clinicians should be vigilant in the assessment of CMT in Mongoloids. No increase of this condition was detected during the last century.

Association of BMP4 polymorphisms with isolated tooth agenesis in a Chinese Han population: a case-control study.

OBJECTIVE: Tooth agenesis is a common craniofacial anomaly in human beings. Mounting evidence has demonstrated that the bone morphogenetic protein 4 gene (BMP4) plays an important role in tooth development. This case-control study was designed to evaluate the association of the polymorphism rs17563 in BMP4 gene with susceptibility of isolated human tooth agenesis in a Chinese Han population. PATIENTS AND METHODS: 335 tooth agenesis cases and 444 healthy controls were included in this study. RESULTS: Although no significant association was observed either in the overall or stratified analysis between the types and the severity of missing teeth. However, significant difference was observed between the anterior and posterior tooth agenesis (APTA) cases and the controls (p = 0.018 for allele distribution and OR = 0.39, 95% CI = 0.15-0.99). Furthermore, the heterozygote (TC) and dominant model (CC+TC) were associated with decreased risk of APTA compared with the control (phet = 0.018, ORhet = 0.39, 95% CIhet = 0.15-0.99 and pdom = 0.042, ORdom = 0.34, 95% CIdom = 0.13-0.87, respectively). CONCLUSIONS: These results indicated that rs17563 in BMP4 gene was potentially associated with APTA in Chinese Han population and further independent studies are required to verify these findings.

[Some aspects of terminology, classification and incidence of hypodontia].

The paper presents the data of literature review on epidemiology, patterns and prevalence of hypodontia depending on race, nationality and gender of the patients. Correlation between congenital absence of the temporary and permanent teeth are discussed as well as the matters of the terminology and classification depending on the severity of this abnormality.

[Identification of mutation in PAX9 gene in a Mongolian family with non-syndromic oligodontia].

OBJECTIVE: To investigate the mutation in transcription factor paired box gene PAX9 in a mongolian family with non-syndromic oligodontia. METHODS: Peripheral blood was collected from 17 core family members (9 unaffected, 8 affected) in this Mongolian family with non-syndromic oligodontia. Mutation in exons of PAX9 gene was identified by PCR amplification and DNA sequencing. RESULTS: A point mutation c.87G > C at position 87 in exon 4 of PAX9 was identified from 8 affected members in the family, which were G/C heterozygous.While the 9 healthy members in the family were homozygous for C which was consistent with normal reference sequence in the GenBank(accession number: NC_000014). CONCLUSIONS: The mutation of c.87G > C (p. Ala240Pro) in exon 4 of PAX9 was likely to cause the non-syndromic oligodontia in this Mongolian family.

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.

Agenesia del tercer molar en una etnia originaria del Norte de Chile: Aymaras / Third molar agenesis in native ethnia from North of Chile: Aymaras

Agenesia es la ausencia de dientes por alteraciones genéticas aisladas o sindrómicas. La agenesia del tercer molar está asociada a malformaciones y es considerada por diversos autores consecuencia de la evolución humana (Larmour et al, 2005). Son los dientes con mayor prevalencia de agenesia junto con segundos premolares e incisivos laterales (Fuller & Denehy, 1984). La prevalen-cia varía entre 9 por ciento y 37 por ciento (McNamara & Foley, 2006), en tanto Arboleda et al. (2006) señalan una prevalencia del 20 por ciento. La literatura señala variables estadísticas porcentuales, por género, por arcada dentaria, por lado y por diente, con escasos artículos sobre grupos originarios de Chile. La población en estudio consistió en 78 individuos, 42 hombres y 36 mujeres, entre 18 y 40 años, de la etnia aymara, sin exodoncias del tercer molar ni tratamientos ortodónticos y sin malformaciones congénitas. Se determinó el grado de mestizaje mediante técnica sero lógica de hemo-aglutinación y por aplicación de la fórmula de Bernstein, que demostró 51 por ciento de mezcla indígena. A cada individuo se le tomó radiografía panorámica para observar presencia o ausencia de terceros molares. Se determinó un 21,79 por ciento de agenesia, con mayor porcentaje masculino. En la muestra total y en hombres hay mayor agenesia de terceros molares mandibulares, en cambio en mujeres existe igual porcentaje de agenesia en ambas arcadas. Predominan agenesias izquierdas, lo mismo se comprueba en el género masculino, mientras que en mujeres se comprueba igual porcentaje bilateral. Predomina la agenesia de un solo molar en ambos sexos. Nuestros resultados fueron comparados con atácamenos y con jóvenes antofagastinos y no se determinaron diferencias significativas al 95 por ciento, coincidiendo con lo señalado en la literatura. La investigación representa un aporte a la antropología del norte de Chile, pero considerando lo reducido de la muestra no es posible determinar...

Agenesis is the absence of teeth by genetic alterations, single or as syndrome. Agenesis of third molar is associated to malformations and is considered by diverse authors a consequence of the human evolution (Larmour et al., 2005). The third molars together with second premolars and lateral incisors are the teeth with greater prevalence of agenesis (Fuller & Denehy, 1984). The prevalence varies between 9 percent and 37 percent (McNamara & Foley, 2006); Arboleda et al. (2006) indicated a prevalence of 20 percent. Literature indicate variable percentage, by gender, dental arches, side and tooth, with few articles on original groups of Chile. The population in study consisted in 78 cases, 42 men and 36 women between 18 and 40 years of the ethnic group of aymarás, without extractions of third molar nor orthodontic treatments and without congenital malformations. Hybridism was determined by means of serum technique by blood agglutination and by application of the formula of Bernstein, demonstrated a 51 percent of indigenous mixture. To each individual a panoramic x-ray was taken to observe presence or absence of third molars. A 21.79 percent of agenesis was determined, with greater percentage among males. Agenesis lower third molar predominates in the sample and in men; however in women are greater agenesis upper third molar. In addition, agenesis predominates of the left side in both sexes, while in men equal bilateral percentage is verified. Agenesis of two molars predominates in both sexes. Our results be are compared with atácamenos and young people living in Antofagasta and statistical analyses did not show significant differences at the 95 percent level, and the results and, in general, agree with those in the literature. This research represents a contribution to the anthropology of the north of Chile, but it is not possible to determine ethnic variables considering the small sample in study.

Agenesia del tercer molar en jóvenes entre 14 y 20 años de edad, Antofagasta, Chile / Third molar agenesis in young people between 14 and 20 years of age, Antofagasta, Chile

Se define agenesia como la ausencia de dientes por alteraciones genéticas aisladas o sindrómicas. La agenesia del tercer molar está asociada a malformaciones y considerada por diversos autores, consecuencia de la evolución humana. Son los dientes con mayor prevalencia de agenesia junto con segundos premolares e incisivos laterales. La prevalencia varía entre 9 por ciento y 37 por ciento, en tanto, Arboleda et al. (2006) señalan una prevalencia del 20 por ciento. La literatura señala variables estadísticas porcentuales, por género, por arcada dentaria, por lado y por diente, con escasos artículos sobre grupos originarios de Chile. La población en estudio consistió en 400 jóvenes (200 hombres y 200 mujeres) entre 14 y 20 años de edad pacientes de una clínica de ortodoncia de la ciudad de Antofagasta, Chile. Todos los pacientes debían ser sanos, sin ningún tipo de malformación general ni maxilofacial, que no hubiesen presentado enfermedades infecciosas que alteraran la odontogénesis y los períodos de erupción, sin exodoncias de ningún tercer molar y sin tratamiento ortodóncico previo al examen radiográfico panorámico. Se determina un 24,75 por ciento de casos de agenesia, con un porcentaje de agenesia respecto del número total terceros molares de un 12,63 por ciento y un 1,58 por ciento de agenesia de terceros molares, en relación al total de dientes. Predomina la agenesia en el género femenino, a nivel mandibular, en el lado derecho, de tipo doble y siendo el diente prevalente el tercer molar mandibular derecho, sin presentarse diferencias estadísticas significativas al 95 por ciento de confianza.

Agenesis is defined as the absence of teeth by single or sindromics genetic alterations. Third molar agenesis is associated to malformations and is considered a consequence of human evolution by several authors. Third molar are the teeth with greater percentage of agenesis along with seconds premolars and lateral incisors. The frequency varies between 9 percent and 37 percent, while Arboleda et al., (2006) indicate a 20 percent of agenesis. Literature indicates statistical variables percentage, by gender, dental arches, side and tooth, however few articles in original groups of Chile. The population in study consisted of 400 young people (200 men and 200 women) between 14 and 20 years of age patient of a clinic of orthodontia of the city of Antofagasta, Chile. All the patients had to be healthy, without any type of general and maxillofacial malformation, who had not presented infectious diseases that altered the odontogenesis and the periods of eruption, without exodontias of third molar and without previous orthodontic treatment to the panoramic x-ray examination. A 24.75 percent of cases of agenesis were determined, with a percentage of 12.63 percent of agenesis with respect to the total number of third molars and 1.58 percent of agenesis of third molar in relation to the total of teeth. Agenesis in the female predominates, at mandibular level, in the right side, of double type and being the prevalent tooth is mandibular right third molar, without appearing significant statistical differences to 95 percent of confidence.

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.

A catalogue of anomalies and traits of the primary dentition of southern Chinese.

Variation in size, form and morphology of the teeth result in anomalies such as macrodontia, microdontia, hyperdontia, hypodontia, double tooth, taurodontism and dens in dente. While traits that may occur more commonly in certain ethnic groups may be considered to be specific to that population. The characteristics of these anomalies and traits are presented along with the prevalence figures for their occurrence in primary dentition of southern Chinese.

Bilateral maxillary canines agenesis: a case report and a literature review.

BACKGROUND: Agenesis of permanent canines is an uncommon condition that affects human teeth. In fact, canine is the most variable positioned tooth, it can be found palatally or facially displaced or ectopically erupted from the dental arch. On the contrary, canine agenesis is a rare finding in Caucasian populations, but it may be relatively more common in Asian groups. This dental anomaly is firstly influenced by genetic, and less often by systemic and environmental factors. Generally, it can occur in association with other dental disturbances or as a solitary anomaly. Prevalence of agenesis permanent teeth varies between 4.5% and 7.4% in general Caucasian populatioN. AIM: The purpose of this report is to discuss the aetiology, prevalence, diagnosis and clinical implications of canine agenesis. CASE REPORT: This paper reports an unusual case of bilateral, congenitally missing canines in a healthy 10 year old Italian male.

Congenitally missing maxillary permanent canines: report of 32 cases from an ethnic Chinese population.

Cases of congenitally missing permanent teeth involving only maxillary canines are uncommon. Prevalence studies have revealed that it is a rare finding in Caucasian populations, but it may be relatively more common in Asian groups. This report describes radiographic findings in 32 Chinese children with congenitally missing maxillary permanent canines. The aetiology of such an anomaly is obscure, but the racial difference in prevalence suggests that genetic factors may be more influential than environmental ones.

Congenitally absent third molars in 12 to 16 year old Singaporean Chinese patients: a retrospective radiographic study.

Third molars have been associated with a host of pathologies and there are risks involved with their surgical removal. They also have the highest incidence of congenital absence of all the permanent teeth. The aim of this study was to determine the prevalence and distribution of congenitally missing third molars in local Chinese patients. The orthopantomographic radiographs of 786 Singaporean Chinese patients aged 12 to 16 years were examined. It was found that 562 (71.5%) of the children had all 4 third molars. Varying degrees of third molar agenesis were noted in the other 224 (28.5%) children. Of these, 43 (5.5%) showed total absence of third molars. There was no significant difference in agenesis between the right and left sides and no sexual predilection was noted. However, more third molars were missing from the maxilla compared to the mandible, the ratio being 3:2.

Dental agenesis in the Dariusleut Hutterite Brethren: comparisons to selected Caucasoid population surveys.

We report the results of a study of the prevalence of nonsyndromic dental agenesis among a sample of 208 individuals (105 females, 103 males) between the ages of 15 and 29 years from a North American religious and genetic isolate, the Dariusleut Hutterites of Western Canada. Direct examination of dental casts, oral examination reports, dental treatment records, and a limited number of dental radiographs reveals congenital absence and/or obvious morphometric reduction of at least one tooth (excluding third molars) in 98 subjects (55 females, 43 males), yielding a prevalence estimate of approximately 47%. This estimate is nearly four times those reported for nonisolate Caucasoid populations of European descent and substantially higher than the elevated prevalences observed in several other isolated populations. Although the prevalence of dental agenesis in the Dariusleut is indeed high, neither the incidence of bilateral agenesis (exhibited at least once in 58% of affected dentitions), number of affected teeth per person (mean, 2.4), morphologic tooth classes affected, or combinations of tooth classes affected ostensibly distinguish them from other populations with similar geographic origins. We conclude that the dental agenesis observed in this North American genetic isolate does not represent a private polymorphism or rare developmental variant. Consequently, the results of further study in these Dariusleut Brethren will be directly relevant to critically testing as yet unresolved hypotheses for the mode of gene action and the relative contributions of hereditary and environmental factors to the reduction of tooth numbers in human dentitions.

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.