scholarly journals Third Molar Agenesis Is Associated with Facial Size

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 650
Author(s):  
Nikolaos Gkantidis ◽  
Manuel Tacchi ◽  
Elias S. Oeschger ◽  
Demetrios Halazonetis ◽  
Georgios Kanavakis
Keyword(s):  
Third Molar ◽  
Evolutionary Process ◽  
Size Reduction ◽  
Permanent Teeth ◽  
Third Molars ◽  
Geometric Morphometric ◽  
Third Molar Agenesis ◽  
Congenitally Missing ◽  
Old Females ◽  
Normal Controls

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.

scholarly journals Third Molar Agenesis in Post-Medieval Chichester

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Devyn Caldwell
Keyword(s):  
Third Molar ◽  
Size Reduction ◽  
Prevalence Rates ◽  
Third Molars ◽  
Dental Anomaly ◽  
The Third ◽  
Third Molar Agenesis ◽  
Dental Reduction ◽  
Evolutionary Step ◽  
Larger Sample

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.   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. 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.

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

2021 ◽  
Vol 2 (2) ◽  
pp. 5-8
Author(s):  
Vivek Padmanabhan ◽  
Omar Khaled AR Abo Mostafa ◽  
Lama M. Kamel Rahhal
Keyword(s):  
Treatment Options ◽  
Third Molar ◽  
Tooth Germ ◽  
P Value ◽  
Chi Square ◽  
Dental Patients ◽  
Dental Tissues ◽  
Third Molar Agenesis ◽  
Chi Square Test ◽  
Congenitally Missing

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. 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 <0.05. Results: The prevalence of bilateral agenesis or congenitally missing mandibular second premolars were at 10.5%. 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.

Third Molar Agenesis and Size Reduction of the Remaining Teeth

Nature ◽  
1963 ◽  
Vol 200 (4905) ◽  
pp. 488-489 ◽  
Author(s):  
STANLEY M. GARN ◽  
ARTHUR B. LEWIS ◽  
ROSE S. KEREWSKY
Keyword(s):  
Third Molar ◽  
Size Reduction ◽  
Third Molar Agenesis

scholarly journals MSX1 and PAX9 Investigation in Monozygotic Twins With Variable Expression of Tooth Agenesis

2013 ◽  
Vol 16 (6) ◽  
pp. 1112-1116 ◽  
Author(s):  
Sofia I. N. Lopez ◽  
Karina S. Mundstock ◽  
Vanessa R. Paixão-Côrtes ◽  
Lavínia Schüler-Faccini ◽  
Carlos A. Mundstock ◽  
...  
Keyword(s):  
Third Molar ◽  
Monozygotic Twins ◽  
Permanent Teeth ◽  
Causative Mutation ◽  
Tooth Agenesis ◽  
Paired Domain ◽  
Exon 2 ◽  
Variable Expression ◽  
Third Molar Agenesis ◽  
Genetic And Environmental Factors

Non-syndromic agenesis of permanent teeth is one of the most common anomalies in human development, a multifactorial characteristic caused by genetic and environmental factors. We describe a pair of monozygotic twins who showed second premolar and third molar agenesis, albeit with different expressions. We studied the DNA of two genes, paired domain box gene 9 (PAX9) and muscle segment homeodomain-homeobox1 (MSX1), encoding transcription factors that earlier studies found were involved in the manifestation of this condition. No specific causative mutation was found. However, we detected a C→T change in MSX1 exon 2 in both twins, suggesting that this polymorphism might be involved in the trait's expression.

scholarly journals Third molar agenesis in modern humans with and without other tooth agenesis

2019 ◽  
Author(s):  
Maya Scheiwiller ◽  
Elias S. Oeschger ◽  
Nikolaos Gkantidis
Keyword(s):  
Third Molar ◽  
Control Group ◽  
Tooth Agenesis ◽  
Evolutionary Trend ◽  
Third Molars ◽  
Modern Humans ◽  
Lower Jaw ◽  
Third Molar Agenesis ◽  
Evolutionary Aspects ◽  
Control Study

Abstract Background The number of teeth in the human dentition attracts special 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 in this long lasting enigma.Methods For this reason, we investigated third molar formation in a sample of 303 individuals with tooth agenesis other than in third molars (agenesis group) and compared it to a sex and age matched control group of 303 individuals without tooth agenesis other than in third molars.Results The 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 other tooth agenesis factor. When considering the percentages of the number 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 upper as well as in the lower jaw, 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 upper and 8.9% in the lower jaw.Conclusion The present results indicate that genetic factors involved in certain tooth agenesis also affect the entire dentition as a whole. Furthermore, the third molars are more vulnerable to factors involved in other tooth agenesis and they are more often affected as a total. These findings seem to be associated with the evolutionary trend in humans towards reduced molar number.

Age estimation from developing third molars

2021 ◽  
pp. 002581722110529
Author(s):  
Yvonne Padmini Wilson ◽  
Phrabhakaran Nambiar ◽  
Hashim Yaacob ◽  
Muhammad Khan Asif
Keyword(s):  
Root Development ◽  
Age Estimation ◽  
Third Molar ◽  
Growth Patterns ◽  
Third Molars ◽  
Panoramic Radiographs ◽  
The Third ◽  
The Subject ◽  
Congenitally Missing ◽  
Demirjian’S Method

We investigated the development of third molars among Malaysians (including variations between jaws and genders) using Demirjian’s method. Dental panoramic radiographs of 1224 subjects aged 8 to 24 years were examined, and the molars were assigned Demirjian et al.’s development grades (A–H). Results indicated that 18.8% had congenitally missing or extracted third molars. Development of molars begins earlier in females (also in the mandible), but by age 9, male children's molar development speeds up with more advanced grades in their middle teens than females. Grade C indicates the subject is a juvenile, while initiation of root development (Grade E), was observed from 13 years on. Grade H can occur in a child aged 18 years who technically is still a juvenile. We compared the development and growth patterns of the third molar from both the maxilla and the mandible.

scholarly journals Assessment of hypodontia in the Turkish patients referring to the orthodontic clinic: A retrospective study

2013 ◽  
Vol 07 (S 01) ◽  
pp. S009-S014 ◽  
Author(s):  
Deniz Uzuner ◽  
Meltem Melik Celik ◽  
Ebubekir Toy ◽  
Candan Okay Turkdonmez
Keyword(s):  
Retrospective Study ◽  
Permanent Teeth ◽  
Third Molars ◽  
Missing Teeth ◽  
Study Results ◽  
Dental Hospital ◽  
Congenitally Missing Teeth ◽  
Pre Treatment ◽  
Turkish Patients ◽  
Congenitally Missing

ABSTRACT Objective: The aim of this retrospective study was to assess the prevalence and distribution of hypodontia in the permanent dentition in a sample of Turkish patients who referred to the Ankara Dental Hospital for orthodontic treatment. Materials and Methods: The pre-treatment orthodontic records of 2530 patients, 1382 girls (54.62%) and 1148 boys (45.38%) between the chronological ages of 7 and 16 years, were examined for evidence of hypodontia. The third molars were excluded in this study. Results: The prevalence of hypodontia in the inspected population was 5% (3.05% for girls, 1.95% for boys). The average number of the congenitally missing teeth per patient was 2.03 (1.08 for girls, 0.95 for boys). The prevalence of the congenitally missing permanent teeth was 34% for the upper laterals, 30% for the lower second premolars, 12.5% for the upper second premolars and 23.5% for the other teeth. Most patients with hypodontia (84.9%) (57.13% for girls, 27.77% for boys) had got missing either one tooth (45.23%) or two teeth (39.67%). Conclusions: The prevalence of hypodontia in girls was higher than in boys in this sample of the Turkish patients. The upper laterals and lower second premolars were consecutively the most symmetrically absent teeth. The prevalence of advanced hypodontia was lower than single and symmetrical hypodontia.

scholarly journals Third Molar Agenesis and Craniofacial Morphology

2009 ◽  
Vol 79 (3) ◽  
pp. 473-478 ◽  
Author(s):  
María José Sánchez ◽  
Ascensión Vicente ◽  
Luis Alberto Bravo
Keyword(s):  
Third Molar ◽  
Craniofacial Morphology ◽  
Control Group ◽  
Third Molars ◽  
Discrimination Analysis ◽  
Third Molar Agenesis ◽  
Mandibular Plane ◽  
Wisdom Teeth ◽  
Group 2 ◽  
Mandibular Third Molars

Abstract Objective: To test the null hypothesis that agenesis of wisdom teeth is not related with any particular craniofacial morphology. Materials and Methods: Ninety-seven patients (aged 13–19 years) were selected and divided into three groups: (1) bilateral agenesis of maxillary third molars, (2) bilateral agenesis of mandibular third molars, and (3) control group without agenesis. Presence or absence of third molars was determined using ortopantomographs. Cephalometric analysis was carried out from lateral teleradiographs, which included linear, angular, and proportional measurements. When data obtained were distributed normally it was analyzed by means of single-factor variance analysis and the Scheffé test (P &lt; .05). When data did not show normality, the Kruskal-Wallis test (P &lt; .05) and the Mann-Whitney test were applied using Bonferroni correction (P &lt; .017). Multivariance discrimination analysis was also carried out. Results: Values obtained for the mandibular plain of Groups 1 and 2 were significantly lower than those of the Control Group (P =.00 and P =.00, respectively). For Group 2 lower face height was significantly less than for the control group (P =.01), whilst the mandibular arch and the articular angle were significantly greater than in the Control Group (P =.000 and P = .02, respectively). Multivariance discrimination analysis obtained a correct classification in 58.8% of cases. Conclusion: The hypothesis is rejected. Agenesis of the maxillary third molars was related to a reduced mandibular plane angle. Patients with agenesis of the mandibular third molars showed a diminished lower third and a mandibular morphology characteristic of the brachyfacial pattern.

scholarly journals Agenesis of all third molars in two half siblings

2015 ◽  
Vol 3 (1) ◽  
pp. 16-18
Author(s):  
Jamie A Kaufer
Keyword(s):  
Autosomal Dominant ◽  
Third Molar ◽  
Future Generations ◽  
Tooth Agenesis ◽  
Third Molars ◽  
Dental Anomalies ◽  
Dominant Inheritance ◽  
Case Discussion ◽  
Third Molar Agenesis ◽  
Genetic Pattern

Tooth agenesis is one of the most common dental anomalies and is influenced by factors including patient genetics. Although there are several specific genes associated with certain patterns of agenesis, there does not seem to be a genetic pattern identified to date that is associated with isolated complete third molar agenesis. This report presents two half-siblings who both express complete agenesis of third molars despite the fact that their shared parent does not express the same phenotype. The case discussion focuses on addressing the potential genetic possibilities including autosomal dominant inheritance and variable expressivity of a mutation.  There remains an uncertainty to the exact gene involved. Potential options include WNT10A and PAX9. The affected individuals are not needing extractions or experiencing complications due to the presence of third molars.  However, the concern remains that there is the potential for more severe expression of the mutation in future generations.

scholarly journals Relationship between Third Molar Agenesis and Other Dental Anomalies

2019 ◽  
Vol 07 (01) ◽  
pp. 023-027
Author(s):  
Stuti Gulati ◽  
Divya Singla ◽  
Sanjay Mittal ◽  
Mandeep Bhullar ◽  
Isha Aggarwal ◽  
...  
Keyword(s):  
Third Molar ◽  
Control Group ◽  
Third Molars ◽  
Dental Anomalies ◽  
Supernumerary Teeth ◽  
Chi Square ◽  
Impacted Canines ◽  
The North ◽  
Third Molar Agenesis ◽  
Chi Square Test

Abstract Objective The purpose of this study was to find the prevalence of dental abnormalities in patients with third molar agenesis, and a comparison was made for the prevalence of those anomalies within the north Indian natives. Materials and Methods Pretreatment records of 518 patients were collected. Out of 518 patients whose records were analyzed, 472 patient records were selected on the basis of inclusion and exclusion standards. Panoramic radiographs and dental casts were analyzed in patients who had an absence of at least one third molar in which absence of any other tooth, presence of supernumerary teeth, presence of impacted canines, and peg-shaped lateral incisors were further assessed. The prevalence of these anomalies was compared with a randomly selected group of patients with presence of third molars that served as controls. Statistical analysis was done using the chi-square test (p < 0.05) and odds ratio. Results The incidence of third molar nondevelopment was found to be 19.2%. The presence of other anomalies was 39.5% in patients with third molar nondevelopment, and difference was statistically significant. The occurrence of impacted canines in patients with absence of third molars was 22%, and presence of third molars was 6.6%. The presence of other dental anomalies, that is, supernumerary teeth and tooth agenesis, was 7.7% in the agenesis group, which was also higher than that in the control group (3.3%) but was not statistically significant. The incidence of peg-shaped lateral incisors was similar in both the groups. Conclusion Impacted canines and total dental anomalies are more often related with absence of third molars than with the presence of third molars.

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