Molar Agenesis Research Articles

CLINICAL DIFFICULTIES AND SOLUTIONS AT CONCOMITANT HYPO-HYPERDONTIA

Purpose: The low frequency of concomitant hypo-hyperdontia and the lack of established clinical protocols in treatment are our motives to analyse our experience in three different clinical cases and derive principles of clinical behaviour. Material and methods: Analysis of the documentation of the 2886 patients, from which three clinical cases were with CHH: case 1 – agenesis of the second upper primary molars and hyperdontia of the upper left lateral; case 2 – Hyperdontia of the upper primary and permanent left lateral and hypodontia of the lower left second premolar; case 3 - two supernumerary (left and right) canines and hypodontia of the lower right second premolar. Results: From all the patients diagnosed and treated by us, hypodontia was found in 7.38% (excluding third molar hypodontia); hyperdontia in 1.9% and only 0.1% have concomitant hypo-hyperdontia. In the three patients, hyperdontia occurs in the frontal segment, and the phenomenon of hypodontia covers the distal segments. Discussion: Following the treatment plans of all three clinical cases, the following stereotype is required as a treatment approach: Solving the problem of hyperdontia (extraction); Levelling dental arches; Solving the problem of hypodontia - placement of implants or closing the space; Retention. In practice, it is found that the solution starts with a relatively smaller problem - hyperdontia, especially in cases where we have access to these teeth. The more serious obstacle is hypodontia, which, if unilateral, leads to disruption of the occlusal ratios. Conclusion: CHH is a rare problem, and the treatment is long, and its favourable outcome depends on early diagnosis.

Patterns of molar agenesis associated with p.P20L and p.R77Q variants in PAX9.

Nonsyndromic tooth agenesis is associated with variants in several genes. There are numerous genotype-phenotype publications involving many patients and kindreds. Here, we identified six Thai individuals in two families with nonsyndromic tooth agenesis, performed exome sequencing, and conducted functional experiments. Family 1 had four affected members carrying the heterozygous PAX9 variant, c.59C>T (p.Pro20Leu). The p.Pro20Leu was previously reported in two families having four and three affected members. These seven cases and Proband-1 had agenesis of at least three third molars. Family 2 comprised two affected members with agenesis of all 12 molars. Both individuals were heterozygous for c.230G>A (p.Arg77Gln) in PAX9, which has not been reported previously. This variant is predicted to be damaging, evolutionarily conserved, and resides in the PAX9 linking peptide. The BMP4 RNA levels in Proband-1's leukocytes were not significantly different from those in the controls, whereas BMP4 levels observed in Proband-2 were significantly increased. Moreover, the p.Arg77Gln variant demonstrated nuclear localization similar to the wild-type but resulted in significantly impaired transactivation of BMP4, a PAX9 downstream gene. In conclusion, we demonstrate that the PAX9 p.Pro20Leu is highly associated with absent third molars, while the novel PAX9 p.Arg77Gln impairs BMP4 transactivation and is associated with total molar agenesis.

Relationship Between Agenesis of Third Molars Skeletal Malocclusion

Background and Aim: Among the agenesis of permanent teeth the most affected tooth is the third molar Mandibularthird molar is an unusual tooth characterized by considerable variability in formation, timing, variation in crownand root morphology and not infrequently, by agenesis. Our aim of this study is to find the frequency of thirdmolar agenesis as well as correlation of skeletal malocclusion and third molar agenesis.Material and Methods: A total of 594 patients (242 males, 352 females) aged between 11 and 25 years were reviewedretrospectively. A tooth was considered developmentally missing when there was no evidence of surgical toothextraction, when there was no any sign of tooth crown mineralization or crypt development with radiolucencyon panoramic radiographs. Patients were divided into five groups according to agenesis of third molars: Patient’sskeletal malocclusion was determined by SNA, SNB and ANB angles as well as Wit’s appraisal and divided intoclass I, II, III malocclusion.Results: Third Molar Agenesis was more common in maxilla than in mandible. Third Molar Agenesis was morecommon in females than males. Significant association was observed between Molar tooth agenesis and Gender.Highest number was observed in females at only 1 third molar was missing followed by 2 third molar missing.Prevalence of third-molar agenesis was more in skeletal class III malocclusion followed by class II and I and it wassignificant statistically.(p≤0.05).Conclusion: Third molar agenesis was most commonly observed in maxillary arch than in mandibular arch andmore common in skeletal Class III followed by Class I and Class II. It was also observed that Third Molar Agenesiswas more common in females than males. Significant association was observed between Molar tooth agenesis andGender.

An Overview of Syndromic Hypodontia

Hypodontia is collectively used to describe the developmental absence of primary or secondary teeth. A number of causes like alterations in the dental lamina development, lack of maturation of tooth germ at the appropriate time, space constraints, systemic and genetic factors may result in missing teeth. With the exception of the third molars, hypodontia is most frequently encountered in lower second bicuspids and upper lateral incisors. Hypodontia is most commonly categorized into two categories: syndromic and non-syndromic hypodontia. Syndromic hypodontia constitutes cases where agenesis of one or more teeth occurs as a result of underlying diagnosable syndromic conditions like ectodermal dysplasia. The more extreme phenotypes of hypodontia include oligodontia with the agenesis of canines, first molars, and second molars and anodontia, and are generally seen in syndromic hypodontia, accompanying and underlying developmental disease. over 200 cleft lip and palate syndromes present with differing extent of hypodontia as a component of their clinical phenotype. The number of missing teeth increases with the extent of cleft. Ectodermal dysplasia consists of a varied group of syndromic presentations resulting from mutations influencing a range of vital congenital pathways such as connection between the overlaying ectoderm and the underlying mesoderm during embryonic growth. Many of these cases present with dental dysplasia and agenesis. In general, dental agenesis may be caused by the arrest of tooth development in the initial bud or cap phase. Care guidelines for such individuals include tooth replacement therapy through fixed and removable prostheses with optional implant support in skeletally mature individuals.

Association of Moderate-Severe Atopic Dermatitis with Dental Anomalies.

Atopic dermatitis is a common inflammatory skin condition with an underlying pathophysiology that may have impact beyond the skin. Previous studies showed a higher prevalence of dental cavities in patients with atopic dermatitis. Our study aimed to establish an association of other dental anomalies in patients with moderate-severe atopic dermatitis. We prospectively recruited 15 patients with moderate-severe atopic dermatitis for a formal dental examination by a paediatric dentist. Hypodontia and microdontia were more prevalent in patients with moderate-severe atopic dermatitis as compared to reference populations and were statistically significant. Dental caries, enamel hypoplasia and agenesis of 3rd molars were also prevalent but did not reach statistical significance. Our study shows a novel finding of higher prevalence of dental anomalies in patients with moderate-severe atopic dermatitis which may warrant further investigation due to its clinical implications.

Third molar development in a London population of White British and Black British or other Black ethnicity.

Population differences in dental development between Black and White ethnic groups have been debated but not previously studied in the UK. Using inappropriate data for dental age estimation (DAE) could lead to erroneous results and injustice. Data were collected from dental panoramic radiographs of 5590 subjects aged 6-24years in a teaching hospital archive. Demirjian stages were determined for left-sided teeth and third molars and data collected regarding hypodontia and third molar agenesis. Third molar development in self-assigned Black British, including other self-assigned Black ethnicity, was compared with that of self-assigned White British subjects. Data were compared for males and females in the two ethnic groups using T-tests for Demirjian Stages A-G of third molar development and Mann-Whitney tests for Stage H once a cut-off age at the maximum age for Stage G had been imposed. Third molar development occurred earlier in subjects of Black ancestry compared to those of White ancestry. While both ethnic groups showed large age ranges for every third molar stage, in female subjects these generally occurred at least 1.5years earlier, and in males at least one year earlier. Hypodontia and third molar agenesis were more prevalent in White British, but the ethnic difference in third molar development persisted in subjects with complete dentitions. This is a large study that confirms ethnic differences in a London population, emphasises the difficulties of establishing the 18-year-old threshold using DAE, and confirms the risk of overestimating the age of individuals of Black ethnicity using White ethnic reference data.

Analyses of oligodontia phenotypes and genetic etiologies

Oligodontia is the congenital absence of six or more teeth and comprises the more severe forms of tooth agenesis. Many genes have been implicated in the etiology of tooth agenesis, which is highly variable in its clinical presentation. The purpose of this study was to identify associations between genetic mutations and clinical features of oligodontia patients. An online systematic search of papers published from January 1992 to June 2021 identified 381 oligodontia cases meeting the eligibility criteria of causative gene mutation, phenotype description, and radiographic records. Additionally, ten families with oligodontia were recruited and their genetic etiologies were determined by whole-exome sequence analyses. We identified a novel mutation in WNT10A (c.99_105dup) and eight previously reported mutations in WNT10A (c.433 G > A; c.682 T > A; c.318 C > G; c.511.C > T; c.321 C > A), EDAR (c.581 C > T), and LRP6 (c.1003 C > T, c.2747 G > T). Collectively, 20 different causative genes were implicated among those 393 cases with oligodontia. For each causative gene, the mean number of missing teeth per case and the frequency of teeth missing at each position were calculated. Genotype–phenotype correlation analysis indicated that molars agenesis is more likely linked to PAX9 mutations, mandibular first premolar agenesis is least associated with PAX9 mutations. Mandibular incisors and maxillary lateral incisor agenesis are most closely linked to EDA mutations.

Exploring the Association Between Genetic Polymorphisms in Genes Involved in Craniofacial Development and Isolated Tooth Agenesis

Tooth agenesis is a common congenital anomaly in humans and is more common in oral cleft patients than in the general population. Many previous studies suggested that oral cleft and tooth agenesis share a similar genetic background. Therefore, this study explored the association between isolated tooth agenesis and genetic polymorphisms in genes that are crucial for craniofacial and tooth development. Panoramic radiographs, anamnesis, and genomic DNA from 273 patients were included. Patients were classified as tooth agenesis present, when at least one permanent tooth was congenitally missing. Patients with syndromes and oral cleft were excluded. Only unrelated patients were included. The genetic polymorphisms in BMP2 (rs235768 and rs1005464), BMP4 (rs17563), RUNX2 (rs59983488 and rs1200425), and SMAD6 (rs3934908 and rs2119261) were genotyped by real-time polymerase chain reaction. Genotype and allele distributions were compared between the tooth agenesis phenotypes and controls by Chi-square test. Haplotype and diplotype analysis were also performed, in addition to multivariate analysis (alpha of 0.05). A total of 86 tooth agenesis cases and 187 controls were evaluated. For the rs235768 in BMP2, patients carrying TT genotype have higher chance to present tooth agenesis [p < 0.001; prevalence ratio (PR) = 8.29; 95% confidence interval (CI) = 4.26–16.10]. The TT genotype in rs3934908 (SMAD6) was associated with higher chance to present third molar agenesis (p = 0.023; PR = 3.25; 95% CI = 1.17–8.99). BMP2 was also associated in haplotype and diplotype analysis with tooth agenesis. In conclusion, genetic polymorphisms in BMP2 and SMAD6 were associated with isolated tooth agenesis.

Prevalence of Third Molar Agenesis in Patients—A Panoramic Retrospective Study

Prevalence of Third Molar Agenesis in Patients—A Panoramic Retrospective Study

Third Molar Agenesis in Post-Medieval Chichester

Third molar agenesis is a dental anomaly that occurs in approximately 25% of people worldwide and results in the complete absence of one or more of the third molars in the dentition. A rise in the prevalence of congenitally absent third molars has been noted in modern populations, and it has been proposed as the final evolutionary step in the dental reduction of the human dentition. &#x0D; Whilst much research has been conducted in modern cohorts, relatively little has been published on third molar agenesis in archaeological assemblages. A post-medieval assemblage from Chichester was visually and radiographically analysed to determine the prevalence of this anomaly. Third molars were measured to determine if there was an association between agenesis and size reduction. Prevalence of agenesis was found to be relatively high at 42.7% and 2 of 8 measurements were found to produce significant differences.&#x0D; Consequently, it can be said that high rates of third molar agenesis are not solely a modern phenomenon, as many prevalence rates in recent populations are lower. However, if we are to assess the significance of size differences in third molars of those with agenesis and those without, and to detect patterns within and between these groups, assemblages with larger sample sizes are needed. In order to better understand the trajectory and evolution of this anomaly, more archaeological assemblages must be examined.

Radiographic evaluation of non-syndromic third molar agenesis in two Mediterranean populations.

Third molar agenesis is a common finding across the world. Many studies have assessed third molar agenesis in different ethnicities and populations. However, there are no such studies in the Italian and Lebanese populations. Our study aims to evaluate the prevalence of third molar agenesis and study the pattern and distribution of agenesis in between genders in Italian and Lebanese Mediterranean populations and compare these findings with other global and Mediterranean populations' studies. Retrospective chart review was conducted based on the history and orthopantomograms of adolescents aged 12 to 21 years to assess the agenesis of third molars in a sample of Italian and Lebanese populations by two experienced dental surgeons twice within 1 month. Descriptive and comparative tests were used to analyze the patterns of ageneses and make comparisons between the two samples. 23.4% of the studied sample had at least one third molar agenesis; females were more likely to have two or more third molar agenesis than males, but neither sex predisposition for single third-molar agenesis was recorded. Both the Italian and Lebanese subgroups seemed to have similar results. The maxillary right third molar was the most common third molar to be absent. Two or more ageneses were more common than one third molar agenesis. Our Mediterranean population results fall within the range reported in the literature and corroborate with the global average prevalence.

Third Molar Agenesis Is Associated with Facial Size.

Simple SummaryMissing third molars is a common occurrence in modern humans with a prevalence of approximately 20% in the general population. The absence of those teeth, however, is not found in other human predecessors. Therefore, there is speculation whether the congenital absence of third molars is part of an evolutionary mechanism that leads to smaller jaws, smaller and fewer teeth, or if their absence is associated with more local developmental factors. In this study, we assessed the size of the cranial base, the maxilla, the mandible and the entire craniofacial complex in individuals missing one or more third molars and compared them with a group with no missing teeth. We showed that in cases with one or more missing third molars, there is a significant decrease in the size of the maxilla, the mandible as well as the entire facial configuration. Additionally, the more missing third molars, the smaller the jaws and the face were. These findings suggest that isolated third molar agenesis is part of a developmental mechanism related to craniofacial size reduction. Whether this mechanism is part of an evolutionary process in humans remains to be seen.Individuals with congenitally missing permanent teeth, other than third molars, present smaller craniofacial configurations compared to normal controls. However, it is not known if agenesis of third molars is part of the same mechanism. Therefore, this study assessed individuals with and without isolated third molar agenesis and tested the relation of this condition to the size of their facial configurations, using geometric morphometric methods. We show that the absence of one or more third molars is associated with a smaller maxilla, smaller mandible and a smaller overall facial configuration. The effect was larger as the number of missing third molars increased. For example, the size of the mandibular centroids in five 16-year-old females with no, one, two, three or four missing third molars showed a size reduction of approximately 2.5 mm per missing third molar. In addition, in cases with third molar agenesis in one jaw only, the effect was also evident on the opposite jaw. Our findings suggest that isolated third molar agenesis is part of a developmental mechanism resulting also in craniofacial size reduction. This might be the effect of an evolutionary process observed in humans, leading to fewer and smaller teeth, as well as smaller facial structures.

Sella turcica bridging and ponticulus posticus calcification in subjects with different dental anomalies

This study aimed to evaluate and compare the bridging and dimensions of the sella turcica and calcification of the ponticulus posticus in subjects with different dental anomalies. Pretreatment recordsof orthodontic patients with palatally impacted canines (n=95), mandibular second premolar agenesis (n=45), maxillary lateral incisor agenesis (n=75), tooth transpositions (TT, n=25), peg-shaped maxillary lateral incisors (n=30), and third molar agenesis (TMA, n=145) were analyzed and compared with the control group (CG) consisting of 145 subjects with skeletal Class I malocclusion and no dental anomalies. The length, diameter, and depth of the sella turcica were calculated for each patient. The degree of sella turcica bridging was scored as type I, II, and III, whereas the extent of ponticulus posticus was classified as Class I, II, and III. Only decreases in the length and diameter of the sella turcica in subjects with TT were found to be statistically significant. Although type II bridging frequency was found to be significantly lower in subjects with mandibular second premolar agenesis, maxillary lateral incisor agenesis, TT, and TMA, type III bridging frequency was found to be significantly higher only in subjects with TMA. The decrease in Class I calcificationfrequencies and the increase in Class II calcification frequencies were found to be significant in subjects with palatally impacted canines, TT, and TMA compared with the CG. In addition, the presence of Class III calcification was found to be significantly more frequent in subjects with TMA than in the CG. Although type II and type III bridging frequencies were found to be higher than in previous studies because of the higher type II bridging frequency in the CG, type II bridging frequency was found to be insignificant. Furthermore, an increased frequency of ponticulus posticus calcification was observed in subjects with palatally impacted canines, TT, and TMA.

Prevalence of Third Molar Agenesis in Patients – A Panoramic Retrospective Study

Background/Purpose: Agenesis is found to be the most common dental anomaly affecting at least 25% of the population. Agenesis is an anomaly where the tooth germ fails to differentiate completely into dental tissues resulting in congenitally missing teeth. The aim of this study was to determine the prevalence of bilateral agenesis of mandibular second premolars. This study also reflects upon the treatment options available for the agenesis of mandibular second premolars.&#x0D; Materials and Methods: Bilateral agenesis was considered as agenesis and unilateral agenesis was excluded from the study. Orthopantamograms (OPGs) of 945 dental patients aged 6 years -30 years were examined for the agenesis of teeth. Descriptive statistics were used to describe the percentages and frequencies were calculated using chi square test and the level of significance was considered if p value was &lt;0.05.&#x0D; Results: The prevalence of bilateral agenesis or congenitally missing mandibular second premolars were at 10.5%.&#x0D; Conclusions: The prevalence rates of bilateral agenesis or congenitally missing mandibular second premolars are more common in males than females. A well informed evidence based decision should be taken for the clinical management of the missing mandibular second premolars.

Association between Third Molar Agenesis and Other Dental Anomalies

Introduction: Third molar teeth are the most common teeth with agenesis. The absence of this tooth also increases the probability of anomalies in other teeth by several times. Since panoramic radiography is used to diagnose and plan treatment in orthodontic patients, along with routine clinical examination, this study aimed to determine the prevalence of third molar agenesis and incidence of other associated anomalies in comparison to that reported for the non-agenesis group using panoramic radiographs. Materials and Methods: In this descriptive-analytical study, the pretreatment records of 562 patients were randomly collected. Out of these subjects, 538 patients were selected based on inclusion and exclusion criteria. The panoramic radiographic images of patients who did not have at least one third molar were assessed with regard to the presence of other dental anomalies, such as dental agenesis, hypodontia, hyperdontia, impacted canine, peg-shaped lateral incisors, ectopic eruption, microdontia, dilaceration, transposition, and transmigration. The prevalence of these anomalies was compared to that of a randomized control group selected from patients with the presence of each four third molars. Results: Out of 538 studied panoramic radiographs, overall, 13.7%, 13.5%, 13.4%, 5.9%, 2.7%, and 1.4% of them had at least one third molar agenesis, canine impaction, peg-shaped lateral incisors, missing teeth, transposition, and hyperdontia, respectively. The frequency rates of impaction and missing teeth were higher in the agenesis group (30% and 40.5%) than those reported for the control group (16% and 2.7%) (p >0.001), respectively. The presence or absence of other dental anomalies was not statistically significant between the two groups and two genders. In addition, the present study demonstrated that the probability of the presence of at least one type of other dental anomalies was higher in individuals with third molar agenesis in comparison to that reported for the control group (p >0.001). Conclusion: Among different types of dental anomalies in the studied population, the probability of impaction and missing teeth was higher in the third molar agenesis group than that of the control group. Furthermore, the prevalence of third molar agenesis was not different between the two genders.

Evidence of dental agenesis in late pleistocene Homo

ObjectiveDifferential diagnosis and tabulation of cases of dental agenesis in Middle and Upper Paleolithic Western Eurasian humans to synthesize this data and to test previous hypotheses about when recent human patterns of third molar agenesis were established. Materials139 Late Pleistocene human remains and 149 individuals from three Epi-Paleolithic/ Holocene non-agricultural comparative collections. MethodsAll remains were visually and radiographically recorded by the author. ResultsIn addition to establishing that third molar agenesis was common during the Late Upper Paleolithic (22,500–10,000 years BP), this study suggests a pattern of increasing prevalence through time. ConclusionsAn increase in the prevalence of third molar agenesis in the Late Upper Paleolithic could indicate selection for dental size reduction and orthognathy, but also bio-cultural changes from more intensive food preparation techniques. SignificanceThird molar agenesis, a well-known developmental defect, is often reported for recent human skeletal collections, but the prevalence of the condition for Pleistocene hominins had not been previously quantified in order to consider patterns through time. Hypotheses posited for the high prevalence of third molar agenesis, or hypodontia in general, in some recent human groups require an understanding of the prevalence of these traits in the past. LimitationsPaleolithic skeletal remains are incomplete, so these values are under-estimations. Individuals are also separated diachronically and geographically and should not be assumed to represent a single population sample. Suggestions for Further ResearchHypotheses on some of the potential selective forces acting on dental size reduction and subsequent agenesis could be tested in recent humans.

Radiographic Assessment of Third Molars Agenesis Patterns in Young Adults

Objective: To determine the prevalence of third molar agenesis and associated characteristics. Material and Methods: A total of 2374 panoramic radiographs were retrieved from the radiological archives and evaluated in a computer monitor under optimum viewing conditions. The basic demographic data (age and sex) and the primary findings regarding the presence or absence of third molars in the maxillary and mandibular arches were recorded systematically in a specially designed proforma. Categorical variables were compared using the Chi-square test. Results: A total of 2000 panoramic radiographs were included in the study, of which 1004 were females (50.2%), and 996 were of males (49.8%). The incidence of third molar agenesis was 486 patients (24.3%). Maxillary third molar showed a higher prevalence of agenesis (28.8%) than mandibular third molars (16.4%) . A total of 1514 patients (75.7%) had third molars in all four quadrants, and the remaining 486 patients (24.3%) had agenesis of third molar tooth in at least one of the quadrants. Single tooth agenesis was observed in 219 (11%) patients, two teeth agenesis in 172 (8.6%) patients, three teeth agenesis in 39 (2%) patients, and four teeth agenesis in 56 (2.8%) patients. Conclusion: The present study exhibited a maximum number of single tooth agenesis. It was also observed that maxillary third molar agenesis is more than the mandibular third molar and the right side is more than the left side. Agenesis of the third molar is more prevalent in males as compared to females.

Third molar agenesis in modern humans with and without agenesis of other teeth.

BackgroundThe number of teeth in the human dentition is of interest both from developmental and evolutionary aspects. The present case-control study focused on the formation of third molars in modern humans aiming to shed more light on the most variable tooth class in the dentition.Materials and MethodsFor this reason, we investigated third molar formation in a sample of 303 individuals with agenesis of teeth other than third molars (agenesis group) and compared it to a sex and age matched control group of 303 individuals without agenesis of teeth other than third molars.ResultsThe prevalence of third molar agenesis in the agenesis group was 50.8%, which is significantly higher than the 20.5% in the control group (p < 0.001). The chance of a missing third molar in the agenesis group was increased by 38.3% (p < 0.001), after controlling for the agenesis in other teeth factor. When considering the amount of missing third molars per individual, a clear tendency towards more missing third molars was evident in the agenesis group compared to the control group. The frequency of bilaterally missing third molars in the agenesis group was 29% in the maxilla, as well as in the mandible, which is about three times higher than the frequency of unilaterally missing third molars (p < 0.001). In the control group, bilaterally missing third molars occurred in 8.6% in the maxilla and 8.9% in the mandible.ConclusionThe present results indicate that genetic factors involved in tooth agenesis affect also the dentition as a whole. Furthermore, the third molars are more vulnerable to factors involved in agenesis of other teeth and they are more often affected as a whole. These findings seem to be associated with the evolutionary trend in humans towards reduced molar number.

Evaluation of the frequency of third molar agenesis according to different age groups.

Third molars (M3s) are the most common congenitally missing teeth. The aim of this study was to compare the frequency of M3 agenesis in two different age groups. This study examined the panoramic radiographic images of 1036 patients. Two groups, each consisting of 518 patients, were arranged based on age ranges. The patients aged 12 to 19 years were in the first group and those 20 years and older were in the second group. The frequency of M3 agenesis was examined in both age groups. The distribution of M3 agenesis by sex and jaw was also recorded, along with the number of M3s affected by agenesis. Chi-square tests were used to examine the relationships between categorical variables. M3 agenesis was observed in 29.3% and 20.5% in the first and second groups, respectively; the difference was statistically significant (P < .01). It was more common in female (27.3%) than in male patients (21.4%), and in the maxilla (11.2%) than in the mandible (5.8%), and the differences were statistically significant (P < .05). It was mostly observed forthemaxilla right M3 (18) (30.9%) and in the single quadrant of the jaws (9.7%). The frequency of M3 agenesis was more common in patients aged 12 to 19 years than in those aged 20 years and older. Additionally, M3 agenesis was more common in females and in the maxilla.

Agenesia de terceros molares y su asociación con otras anomalías dentales en una población peruana.

Objective: The purpose of the present study was to determine the association between agenesis of the third molar and other dental anomalies. Materials and Methods: This was an observational, retrospective, cross-sectional and analytical study. The sample included 367 patients, aged 14 to 20 years old with adequate digital panoramic radiography. Patients with syndromes, who had extractions of any third molar and with orthodontic treatment prior to panoramic radiographic examination, were excluded. For data collection, each radiograph was recorded with patient code, sex and age. Results: The prevalence of third molar agenesis was 20.71%. Subsequently, patients were divided into two groups, with agenesis of at least one third molar and a control group; the prevalence of other dental anomalies was 48.69% of third molar agenesis group and 21.31% in the control group. A highly significant association was found between the presence of third molar agenesis and the presence of other tooth abnomalities (p= 0.0000; contingency coefficient = 0.2425).The most frequent dental anomaly was dental inclusion with 20.44% of the population studied; followed by the agenesis of other teeth (7.90%) and finally the presence of supernumerary teeth (1.63%). Conclusions: This study demonstrates that there is an association between third molar agenesis and other dental abnormalities, with a higher prevalence of dental abnormalities in patients with third molar agenesis.