Morphological Variation of the Baka Pygmies’ Deciduous Second Molars 

2021 ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando Ramirez-Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Distal Region ◽  
Dental Morphology ◽  
Second Molar ◽  
Natural Logarithm ◽  
Dental Crowns ◽  
Human Sample ◽  
Molar Morphology ◽  
South Americans ◽  
Deciduous Molars ◽  
General Size

Abstract The Baka pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-pygmies. However, the Baka’s dental morphology, as several other aspects of their biology, is still understudied. In this study we explore the Baka’s upper and lower second deciduous molars variation in comparison to a human sample including Africans, Asians, Europeans, and South Americans by means of 3D geometric morphometrics. We analyzed both the outer and inner aspect of the dental crowns, as well as their general size based on the natural logarithm of centroid sizes. Our results show largely overlapping morphologies between populations, especially for the lower molars. The distal region of the second molars is the most variable, with the Baka’s lower second molars showing the most extreme range of variation for this aspect and in terms of crown height. Upper and lower second molars showed high morphological covariation (RV=0.82). The Baka and South Americans’ second molars were confirmed among the largest in our sample. Despite of the Baka’s particular growth pattern, long-lasting isolation and extreme dental variation, it is not possible to distinguish them from other populations on the basis of their second molar morphology only.

scholarly journals Morphological variation of the deciduous second molars in the Baka Pygmies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Morphological Variation ◽  
Growth Pattern ◽  
Distal Region ◽  
Dental Morphology ◽  
Human Sample ◽  
Different Populations ◽  
Dental Traits ◽  
South Americans ◽  
Range Of Variation

AbstractThe Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.

scholarly journals Morphological Variation of the Deciduous Second Molars in the Baka Pygmies

2021 ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Morphological Variation ◽  
Growth Pattern ◽  
Distal Region ◽  
Dental Morphology ◽  
Human Sample ◽  
Different Populations ◽  
Dental Traits ◽  
South Americans ◽  
Range Of Variation

Abstract The Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV=0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.

Using three-dimensional geometric morphometric and dental topographic analyses to infer the systematics and paleoecology of fossil treeshrews (Mammalia, Scandentia)

2020 ◽  
Vol 94 (6) ◽  
pp. 1202-1212
Author(s):  
Keegan R. Selig ◽  
Eric J. Sargis ◽  
Stephen G.B. Chester ◽  
Mary T. Silcox
Keyword(s):  
Evolutionary History ◽  
Effective Means ◽  
Three Dimensional ◽  
Dental Morphology ◽  
Geometric Morphometric ◽  
Second Molar ◽  
Morphometric Analyses ◽  
History Of ◽  
Dietary Ecology ◽  
Molar Morphology

AbstractTreeshrews are small, Indomalayan mammals closely related to primates. Previously, three-dimensional geometric morphometric analyses were used to assess patterns of treeshrew lower second molar morphology, which showed that the positions of molar landmarks covary with intraordinal systematics. Another analysis used dental topographic metrics to test patterns of functional dental morphology and found that molar curvature, complexity, and relief were an effective means for examining patterns of variation in treeshrew dietary ecology. Here, we build on these analyses by adding two fossil taxa, Prodendrogale yunnanica Qiu, 1986 from the Miocene of China and Ptilocercus kylin Li and Ni, 2016 from the Oligocene of China. Our results show that Pr. yunnanica had a dental bauplan more like that of a tupaiid than that of a ptilocercid, but that the extant tupaiids, including Tupaia and Dendrogale, are more similar to one another in this regard than any are to Prodendrogale. This is contrary to our expectations as Prodendrogale is hypothesized to be most closely related to Dendrogale. Ptilocercus kylin, which has been proposed to be the sister taxon of Pt. lowii Gray, 1848, is characterized by dental morphology like that of Pt. lowii in crest and cuspal position but is interpreted to have been more frugivorous. It has been claimed that Ptilocercus has undergone little morphological change through time. Our results suggest that Pt. kylin was more ecologically distinct from Pt. lowii than previously proposed, providing a glimpse into a more complex evolutionary history of the group than had been inferred.

scholarly journals Root Canal Configuration of the Maxillary Second Permanent Molars in Pakistani Subpopulation

2021 ◽  
Vol 30 (03) ◽  
pp. 209-214
Author(s):  
Mansoor Khan Khan ◽  
◽  
Alia Ahmed ◽  
Muhammad Qasim Javed
Keyword(s):  
Root Canal ◽  
Dental Morphology ◽  
Cross Sectional ◽  
Second Molar ◽  
Morphological Variations ◽  
Molar Teeth ◽  
Permanent Molars ◽  
Root Canal System ◽  
International University

OBJECTIVE: The aim of the study is to assess the variations in the root canal configuration of maxillary second permanent molars in the Pakistani subpopulation by using different clinical aids in vivo. METHODOLOGY: The Cross-sectional analytical study was conducted from April to October 2018 at the College of Dentistry, Riphah International University, Pakistan. The root canal configurations of Maxillary second molars were evaluated in 95 adult patients that presented to the Operative Department, after obtaining consent. After access cavity preparation the orifices were identified and cross checked using 2.5x magnification and different clinical tests. Data analysis was done by utilizing SPSS version 23. RESULTS: Out of the 95 teeth 6(6.3%) teeth had a single canal, 7(7.4%) teeth had two canals, 58(61.1%) teeth had three canals and 24(25.3%) teeth had four canals. Age-wise analysis of the frequency of different canals showed that prevalence of molars with three canals was significantly higher in the subjects with age between 41 and 50 years. Conclusion: Overall, the study noted four morphological variations in the root canal configuration of Maxillary second molar teeth in Pakistani subpopulation. Hence, while executing the endodontic treatment in the maxillary second molars a thorough assessment of the root canal system should be carried out. The results of the study can guide Pakistani dentists. KEYWORDS: Permanent Maxillary second molar, Dental Morphology, Endodontics, Pakistan

scholarly journals Morphological characterization of incisors and molars of an african descent group of Cali, Valle del Cauca (Colombia)

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
Annie Garcia ◽  
Fernando Gustin ◽  
Catalina Quiñonez ◽  
Lina Sacanamboy ◽  
Mery-Hann Torres ◽  
...  
Keyword(s):  
African Descent ◽  
Low Frequency ◽  
Bilateral Symmetry ◽  
Dental Morphology ◽  
Mixing Processes ◽  
Cross Sectional ◽  
Second Molar ◽  
Descent Group ◽  
Valle Del Cauca ◽  
Groove Pattern

Objectives: To determine the frequency, variability, sexual dimorphism, correlation and bilateral symmetry of 13 non-metric dental crown traits (NMDCT) in incisors and molars of afro descent group of Cali, Valle del Cauca (Colombia)Material and methods: Quantitative cross-sectional study that characterizes the dental morphology of the central and lateral upper incisors (11, 12, 21, 22) and first and second upper and lower molars (16, 17, 26, 27, 36, 37, 46, 47) by ASUDAS system of observation, recording and analysis reported in the literature; from 60 models of study (34 female and 26 male) obtained from a afro descent group with aged between 7 to 17 years.Results: Was obtained winging and crowding mid frequencies, high frequency of shovel-shape in central and lateral incisors, low frequency of Carabelli cusp, low frequency of metaconule, reduction of hypocone absent, P point expression of protostylid, low frequency of deflecting wrinkle, groove pattern configuration Y5 (lower first molar) and +5 and +6 (lower second molar). NMDCT not sexually dimorphic (except hypocone reduction and groove pattern), have low correspondence and have bilateral symmetry. A p<0.05 was considered statistically significant.Conclusions: The frequency and variability of the 13 NMDCT allowed determining that the group of African descent is part of Caucasoid Dental Complex with Mongoloid Dental Complex influence, due to mixing processes and ethno historic settlement of the southeastern region of Cali. Key words: Dental anthropology, dental morphology, incisors, molars, non-metric dental traits, African descent, Afrocolombian.

Anatomic features of mandibular second molars root canals in a Yemeni population: cone-beam computed tomography

2019 ◽  
Author(s):  
Elham M. Senan ◽  
Hatem A. Alhadainy ◽  
Ahmed A. Madfa
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Type I ◽  
Type Ii ◽  
Second Molar ◽  
Root Canals ◽  
Canal Systems ◽  
Section Type ◽  
Molar Morphology

Abstract Background: This study aimed to identify and characterize root and canal morphology and the prevalence of C-shaped canals of mandibular second molars (MSMs) in a Yemeni population using cone-beam computed tomography (CBCT). Methods: CBCT images of 500 right and left MSMs with mature roots were taken from 250 Yemeni individuals and analyzed for the following features: number of roots, total number of canals orifices within the tooth and number of canals orifices in each root, type of roots, either fused or separated, shape of root in cross section, type of canal configuration in each root, presence of C-shaped canal, and primary variations in the morphology of root and canal systems. Results: Molars with separated two roots predominated (89.6%), fused two roots were 9%, separated three roots were 0.6% and one root MSMs were 0.8%. Molars with three canals orifices were the most common. Mesial root was mainly ribbon-shaped (60.5%) and distal root was mainly kidney-shaped (50.7%). Type II and Type I canal configurations were the most frequent in mesial root (56.9%) and distal root (91.3%), respectively. C-shaped canals were found in 9%. Six variants were found with variant 3 was the most common (71%). Conclusions: Yemeni permanent MSMs have mainly two separated roots. Mesial root is mostly ribbon-shaped and distal root is mainly kidney-shaped. Vertucci type II and I canal configurations showed the higher incidence in mesial and distal roots, respectively. C-shaped canals were found in 9%. Keywords: Cone-beam computed tomography, C-shaped canal, mandibular second molar, morphology, root canal, Yemen

Reassessment of Lower Eocene Seggeurius amourensis: aspects of primitive dental morphology in the mammalian order Hyracoidea

1993 ◽  
Vol 67 (5) ◽  
pp. 889-893 ◽  
Author(s):  
Nicholas Court ◽  
Mohamed Mahboubi
Keyword(s):  
Dental Material ◽  
Dental Morphology ◽  
Crown Height ◽  
Lower Eocene ◽  
Precise Characterization ◽  
Molar Morphology ◽  
Upper Molar ◽  
Lower Molar

New lower dental material of the fossil hyracoid mammal, Seggeurius amourensis Crochet, 1986, from Eocene deposits of the Southern Atlas in Algeria, has prompted a reevaluation of the genus. The dentition as a whole is first described in detail, thus providing a more precise characterization of the genus than has hitherto been available. Peculiarities, particularly in upper molar morphology, are sufficient to uphold a generic distinction. However, based largely on lower molar morphology Seggeurius amourensis is transferred from the subfamily Geniohyinae to Saghatheriinae. In the upper molars, absence of a postmetacrista and the presence of a preprotocrista continuous with the parastyle are interpreted as primitive features in hyracoids. In the lower molars, extreme reduction of the paracristid and the presence of a mesoconid are also considered primitive for hyracoids. These features together with small size, bunodonty, low crown height, and very simple premolar morphology indicate that Seggeurius amourensis is the most primitive hyrax yet recovered.

scholarly journals Dental morphology of deciduous molars from late Neolithic Caves of the Meuse River Basin of Belgium

2018 ◽  
Vol 31 (2) ◽  
pp. 18-26
Author(s):  
Frank L'Engle Williams ◽  
Rebecca L George ◽  
Caroline Polet
Keyword(s):  
River Basin ◽  
Dental Morphology ◽  
Late Neolithic ◽  
Potential Relationship ◽  
Dental Traits ◽  
Deciduous Molars ◽  
Range Of Variation ◽  
Dental Casts ◽  
Meuse River

Nearly 200 karstic caves of the Meuse River Basin of Belgium preserve collective burials dated to the Late Neolithic. The gnathic remains from five well preserved sites provide an opportunity to explore potential relationship among these cave burials. The cave burials of Hastière Caverne M, Hastière Trou Garçon C, Maurenne Caverne de la Cave, Sclaigneaux and Bois Madame are dated to circa 4,635 to 3,830 years BP. Dental casts from mandibular and maxillary deciduous molars are scored using the ASUDAS. Carabelli’s trait varies from a small, Y-shaped depression to a full cusp, and the largest ones are found at Hastière Caverne M. The mandibular first molars have three to five cusps and the second molars have five, with one instance of six cusps at Bois Madame, which exceeds the range of variation for other dental traits.  The hypoconulid ranges from small to very large. A metaconulid is absent or small.           Although the results are contingent on idiosyncratic preservation, differences in the frequencies of traits exist between the earlier cave burial from Hastière Caverne M and the late/final Neolithic burials of Sclaigneaux and Bois Madame, the latter of which is the most variable in the expression of dental traits.   

scholarly journals Parametric model of the structure of the second molar of a human lower jaw

2020 ◽  
pp. 19-28
Author(s):  
Anna Genrikhovna Yanishevskaya ◽  
Zhanna Vladimirovna Golikova ◽  
Fedor Nikolaevich Pritykin ◽  
Vasilii Gerasimovich Khomchenko
Keyword(s):  
Three Dimensional ◽  
Parametric Model ◽  
Dental Students ◽  
Heterogeneous Information ◽  
Second Molar ◽  
Advantages And Disadvantages ◽  
Surface Areas ◽  
Dental Crowns ◽  
Dental Pathology ◽  
Scientific Results

In this paper the design of a parametric tooth model is considered, with the help of which it is possible to study the development of dental pathology. This model allows you to create a tooth prosthesis, with minimal intervention of the dentist, by creating a three-dimensional image of the studied tooth, close in architecture to the real one.&nbsp;Particular attention is paid to the study of the geometry of the tooth - the second molar. Based on the analysis of the presented initial data, additional characteristics were introduced, due to which the geometry of the surface areas of the tooth model is calculated. The article discusses the advantages and disadvantages of visualization methods used in this area to solve problems associated with the analysis of complex and heterogeneous information, and also presents conclusions on practical and scientific results. A parametric model of a tooth was built, which describes its geometry in comparative detail. The main necessary parameters and their limitations are determined. The obtained calculations of the geometric shape of the tooth can be used to study and analyze the biomechanics of teeth, the principles of differential diagnosis of pain, planning future iatrogenic intervention, as well as algorithms for the treatment of prosthetic disorders, provides the doctor with all the necessary tools. The constructed crown part of the tooth in the AutoCAD system can be used for teaching dental students. This model can be used for scientific and practical activities of students on the modeling and restoration of dental crowns.

Sign in / Sign up

Export Citation Format

Share Document