High Prevalence Of Hypodontia Research Articles

An International Investigation of Molar Incisor Hypomineralisation (iMIH) and Its Association with Dental Anomalies: Development of a Protocol

Molar incisor hypomineralisation (MIH) is a common disorder of tooth development, which has recently been found to be associated with a higher prevalence of hypodontia. The aim of this international multicentre study is to determine the association between MIH and other developmental anomalies in different populations. Investigators were trained and calibrated for the assessment of MIH and dental anomalies and ethical approvals obtained in each participating country. The study aimed to recruit 584 children with MIH and 584 children without MIH. Patients aged 7-16 years who attend specialist clinics will be invited to participate. Children will undergo a clinical examination to determine the presence and severity of MIH, using an established index. The presence of any other anomalies, affecting tooth number, morphology, or position, will be documented. Panoramic radiographs will be assessed for dental anomalies and the presence of third permanent molars. Statistical analysis, using a chi squared test and regression analysis, will be performed to determine any differences in dental anomaly prevalence between the MIH and non-MIH group and to determine any association between dental anomalies and patient characteristics. This large-scale study has the potential to improve understanding about MIH with benefits for patient management.

WNT10A and RUNX2 mutations associated with non-syndromic tooth agenesis.

The goal of this study was to examine the prevalence of WNT10A and RUNX2 mutations and assess their potential impact on the phenotype of non-syndromic tooth agenesis. The study included 30 participants with non-syndromic tooth agenesis, divided into hypodontia (n = 24) and oligodontia forms (n=6), and 42 unaffected family members. Genomic DNA from buccal epithelial cells was used for polymerase chain reaction amplification of functionally important exons of the WNT10A and RUNX2 genes. Direct sequencing reactions were performed to confirm the presence of mutations. The trend of increasing prevalence of WNT10A mutations and a slight increase in the prevalence of RUNX2 mutations were revealed in tooth agenesis cases compared to unaffected family members. There was a higher prevalence of hypodontia than oligodontia, increased frequency of females over males with missing teeth, and a wide phenotypic variability was observed in individuals and families analyzed. The common missense mutations (p.Phe228Ile, p.Arg113Cys, p.Asp217Asn, and p.Gly165Arg) and c.114-56T>C in the WNT10A gene and in-frame-deletion/insertions (11A, 24Q, 30Q), synonymous variant c.240G>A, and 424-33dupC in the RUNX2 gene were identified. These findings highlight an important role of WNT10A and RUNX2 mutations in the genetic etiology of non-syndromic tooth agenesis.

Prevalence of Hypodontia in Orthodontic Patients at Nobel Medical College, Biratnagar

Introduction: Hypodontia or tooth agenesis is the most common developmental anomaly in craniofacial region. The multitude of problems in patients with hypodontia includes aesthetic, periodontal damage, malocclusion, inarticulate speech and alveolar bone deficiency. This commonly encountered condition in orthodontic department has variable site of occurrence, sometimes associated with syndromes. Objective: To know the patterns and types of hypodontia in orthodontic patients attending orthodontic department at Nobel Medical College, Biratnagar. Methodology: Cross sectional study of 260 orthodontic patients’ pre-treatment records i.e., casts, orthopantomogram, lateral cephalometric radiographs and photographs were taken as study materials. Descriptive statistics was used to analyze the data and chi square test was used to find the level of significance among genders. Results: Congenital absence of one or more teeth was observed in 28 out of 260 patients, with a frequency of 10.8%. Among the hypodontia patients, 11 (4.23%) were males and 17 (6.54%) were females. Of all 69 missing teeth, the most (68%) was observed in class I group, and the least amount belonged to class III group (10%). Conclusions: The higher prevalence of hypodontia in Orthodontic patients in this region warrants careful inspection and investigation before embarking on the diagnosis and treatment planning.

An orthopantomographic study of prevalence of hypodontia and hyperdontia in permanent dentition in Vadodara, Gujarat.

Developmental anomalies in the number of teeth can result from disturbances in the developing dental lamina of the tooth. The dental lamina may become hyperactive leading to the formation of a supernumerary tooth or may fail to proliferate leading to the congenital absence of a primary or permanent tooth. The aim of the study was to assess the prevalence and distribution of hypodontia and hyperdontia in permanent dentition, excluding the third molars in children in Vadodara, Gujarat. A descriptive, analytical, and cross-sectional study was conducted to determine the above-mentioned aims. In the study, panoramic radiographs of 1816 children (967 girls and 849 boys), aged 8 to 14 years were recorded and inspected for anomalies in the number of teeth. The data was analyzed using SPSS version 10.00 (Statistical Package for the Social Sciences, Chicago, USA). Descriptive statistics and Chi-square-test were used to compare the results. The level of significance was set at 0.05. The prevalence of hypodontia was 11.01%, and the most frequently absent tooth was the maxillary lateral incisor. There was an increased prevalence of hypodontia in females and in the mandibular arch of the permanent dentition. The prevalence of hyperdontia was 2.97% and the most common supernumerary tooth was mesiodens. There was an increased prevalence of hyperdontia in males and in the maxillary arch of the permanent dentition. There was a high prevalence of hypodontia and a low incidence of hyperdontia in the studied population. Prompt diagnosis of these anomalies can help plan treatment modalities at an early age to establish a functional and esthetic dentition.

Hypodontia Prevalence over Four Decades in a Slovenian Population

This study was performed to determine the prevalence of hypodontia of permanent teeth in the Slovenian population and whether such prevalence is associated with the year of birth. The prevalence of hypodontia in the Slovenian population, both male and female, and the association between tooth types, the upper or lower arch, the associated dental anomalies, and orthodontic treatment were studied using interviews and oral and panoramic radiographic examinations of 2,546 Slovenians born in years 1966, 1976, 1986, and 1996. The data were processed using Chi-square test. Among the 2,546 subjects studied, 307 teeth were missing in 175 subjects. The overall prevalence of hypodontia, excluding the third molars, was 6.9%; and there was no statistically significant difference with the year of birth. The most commonly missing teeth were the mandibular second premolar (38.8%), followed by the maxillary lateral incisors (32.6%). The majority (86.9%) of patients with hypodontia were missing only one or two teeth. Subjects with hypodontia (54.9%) were more often involved in orthodontic treatment than subjects without hypodontia (20.5%). The relatively high prevalence of hypodontia and its frequent association with other dental anomalies emphasizes the importance of dental examination in early childhood with radiographic screening for hypodontia as standard public oral health policy. The relatively high prevalence of hypodontia in Slovenians and its frequent association with other dental anomalies emphasizes the importance of dental examination with radiographic screening of hypodontia in childhood as part of public oral health policy.

The prevalence and distribution pattern of hypodontia among orthodontic patients in Southern Iran.

Objectives:To evaluate the pattern and prevalence of hypodontia and its association with different malocclusions among orthodontic patients in southern Iran.Materials and Methods:In this study, a total of 494 records of orthodontic patients (162 males, 332 females) were evaluated. To investigate percent of hypodontia pertinent information of patients was evaluated. Chi-square and Fisher's exact tests were used for statistical analysis.Results:The prevalence of tooth agenesis was 7.66%. Thirty-eight patients were found to have at least one tooth missing. Number of patients having hypodontia was the most in class III patients, whereas the number of missing teeth was more in class II sample. However, it was not statistically significant (P = 0.569). Upper lateral incisor (27.95%), lower second premolar (21.51%), and upper first premolar (12.9%) were respectively the most frequently absent teeth. There was not statistically significant difference between sexes (P = 0.580). Hypodontia observed to be more bilaterally, in the upper arch and in the left side.Conclusion:The pattern and prevalence of hypodontia is different among races and ethnic groups. In our study population, hypodontia was found to be 7.66%. Higher prevalence of hypodontia in the maxillary arch and in class III patients may be considered as an etiologic factor.

Van der Woude syndrome: dentofacial features and implications for clinical practice

Van der Woude syndrome (VWS) is the most common clefting syndrome in humans. It is characterized by the association of congenital lower lip fistulae with cleft lip and/or cleft palate. VWS individuals have a high prevalence of hypodontia. Although caused by a single gene mutation, VWS has variable phenotypic expression. This study aimed to describe the range of clinical presentations in 22 individuals with VWS to facilitate its diagnosis. A retrospective study of 22 patients with a diagnosis of VWS was undertaken at the Australian Craniofacial Unit (ACFU) in Adelaide. Three extended families with affected members were included in the study cohort. The overall prevalence of lip pits in this study cohort was 86%. Cleft phenotypes included bilateral cleft lip and palate (32%); unilateral cleft lip and palate (32%); submucous cleft palate (23%); and isolated cleft hard and soft palate (9%). Missing permanent teeth were reported in 86% of affected individuals. Submucous cleft palate in VWS may go undiagnosed if the lower lip pits are not detected. Associated hypodontia and resultant malocclusions will also require management by a dental team.

The aetiology of hypodontia: The prevalence, severity and location of hypodontia within families

AimsPrevious studies have indicated that hypodontia has a significantly higher prevalence in the relatives of affected individuals than in the general population. This study aims to examine further the roles of genetic and environmental factors in the aetiology of hypodontia by investigating the relationship between the severity and distribution of hypodontia between family members, and any discernable effect of maternal health during pregnancy and birth weight. Methods and results117 first degree relatives of 41 index patients were examined clinically and radiographically to identify the presence, severity and location of hypodontia. Both siblings and parents of index patients had a higher prevalence of hypodontia than the general population. The number and location of missing teeth was not related to the number and location of missing teeth in parents or siblings. The expression of hypodontia within a family was not affected by maternal health during pregnancy. ConclusionsThe variation found in the expression of hypodontia within families suggests that its occurrence is not solely determined by genetic factors, but epigenetic and environmental factors probably also are important. This finding is consistent with a multifactorial aetiology for this condition.

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 examined 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.

A review of tooth formation in children with cleft lip/palate

The literature on tooth formation in children with cleft lip and/or palate is reviewed. The main focus of interest is the association of cleft type and dental abnormalities in number, size, shape, timing of formation, and eruption and cause of the abnormalities. The upper lateral incisor is the most susceptible to injury in the area of cleft in both deciduous and permanent dentitions. This tooth is affected in most instances, even in the cases of microforms of the cleft lip. The prevalence of hypodontia increases strongly with the severity of cleft. More teeth are congenitally missing from the upper jaw than from the lower jaw; however, in the permanent dentition both jaws are affected. Very high prevalence of hypodontia are observed in connection with the Van der Woude syndrome associated with cleft and with the Pierre Robin anomaly. Hypodontia is similarly prevalent in subjects with isolated cleft palate with and without a positive family history of clefts. The prevalence of hypodontia varies largely in different populations. Asymmetric formation of the contralateral teeth is a milder form of hypodontia. The prevalence of asymmetrically developing pairs of teeth is far more common in children with clefts than in children with normal palates or lips. In the permanent dentition the timing of tooth formation is delayed in children from all cleft groups compared to noncleft children. The delay lengthens (with increasing severity of cleft) from 0.3 to 0.7 years and is similar in all permanent teeth in both jaws. In children with hypodontia, the delay is still more severe. As the child becomes older, the delay may increase. The size of the permanent teeth is smaller than in noncleft children and the metric asymmetry of the crown or root size is apparent in both jaws. Enamel defects and abnormalities in shape and size of both deciduous and permanent teeth are far more common in children and fetuses affected with cleft than in normal subjects. These abnormalities occur in both jaws. Dental abnormalities in number, size, shape, timing of formation, eruption, and the cleft itself seem to have a common cause in most instances. The postnatal environmental factors-nutrition, infections, and surgical treatment—may have an effect only on enamel defects and, perhaps, in some instances, on agenesis of the permanent teeth.

Hypodontia: a polygenic trait--a family study among Israeli Jews.

A high prevalence of hypodontia was detected among 820 first degree relatives of 305 probands and there was an increased risk if a second family member was affected. Hypodontia is a common trait in the population, and a deviation from normal sex ratio was observed in those affected. These results suggest a polygenic mode of inheritance.