Carabelli Trait Research Articles

DIMENSIONAL AND NON-DIMENSIONAL DENTAL ASYMMETRY RELATIONSHIPS IN MAN

SUMMARY The relationship between metrical and non-metrical fluctuating dental asymmetry was evaluated in three human population groups. Data were gathered for the Carabelli trait and the canine distal accessory ridge (CDAR) in 106 South African ‘Blacks’∗ (56 males, 50 females), 125 South African ‘Whites’† (59 male, 66 female) and 202 Paraguayan Lengua Indians (100 male, 102 female). When the levels of asymmetry for these two traits were compared to odontometric asymmetry of maxillary canines and first molars, a significant lack of association was noted. While Lengua Indians were found to be the least morphologically asymmetric, our data failed to offer an insight into the usefulness of fluctuating dento-morphological asymmetry as an indicator of environmental stress.

The carabelli trait in the mixed deciduous and permanent dentitions of five South African populations

The Carabelli trait in South African negroids, caucasoids, Coloured (Peninsula and Namaqualand) and Indians, classified according to Alvesalo, Nuutila and Portin (1975; Acta odont. scand. 33, 191–197) showed generally peak frequency of expression for dm 2 falling into class 3 and for M 1 into class 4, that dm 2 displays more negative expression (class 2 and 3) and M 1 more positive expression (class 4 and 5) and that overall expression in dm 2 is higher than in M 1. The Indian group was an exception with peak frequencies in class 2 for dm 2 and class 1 (right) and class 2 (left) for M 1. There was no sex dimorphism and there was a tendency for concordance of expression between sides but not within sides.

The dentition of the Ladakhi, India.

Five morphologic crown traits were observed in a sample of 50 Ladakhi males of the state Jammu & Kashimir in India. The Ladakhi dentitions are characterized by high frequency of shoveling, a well-reduced hypocone in second molars and mandibular molar with five cusps. They exhibit low frequency of CARABELLI's trait and Dryopithecus pattern. When the Ladakhi crown trait frequencies were compared with those of six other Asian populations, the Ladakhi dentitions showed the closest affinities to Sherpas dentitions. The tooth crown morphology of the Ladakhi lies between the Mongoloids and the Caucasoids. The biological distances among the compared populations are closely associated with geographical distances.

Deciduous dental morphology and the biological affinities of a late Chalcolithic skeletal series from western India

Morphological variations of the dental crown and roots provide valuable data for determining the genetic affinities and evolutionary adaptedness of prehistoric human skeletal populations. This paper documents morphological variations of a sample of deciduous teeth from the late Chalcolithic farming village of Inamgaon (1600-700 B.C.) in western India. Hanihara's (1963) grading system of deciduous dental traits was employed in assessing the degree of expression of shovel-shape of incisors, cusp number of upper and lower first molars, hypocone variation, Carabelli's trait, cusp number of lower second molars and the protostylid. Turner's (1970) classification was used to determine presence and size of accessory cusps: entoconulid (C-6) and metaconulid (C-7). Comparative evaluation of the Inamgaon deciduous dental data is hampered by the absence of data for dental features of living and prehistoric South Asian populations. Many of the traits observed in the Inamgaon series exhibit a frequency of occurrence intermediate between figures characteristic of the "Mongoloid" dental complex and the "Caucasoid" dental complex.

An analysis of the Carabelli trait in the mixed deciduous and permanent human dentition

Permanent first and deciduous second maxillary molars were examined on dental casts of 240 persons. A high degree of equivalence of Carabelli-trait expression between deciduous and permanent molars was demonstrated using the Wilcoxon matched-pairs signed-rank test and chi-square tests. Kolmogorov-Smirnov two-sample tests confirmed a lack of sex dimorphism of trait incidence and expression in permanent and deciduous molars. It is hypothesized that the high degree of within-individual equivalence suggests a low epigenetic and high genetic influence on Carabelli-trait expression and that the findings support the clonal rather than the field theory of tooth morphogenesis.

Classificatory reliability of the carabelli trait in man

Classificatory reliability of the Carabelli trait was evaluated using randomly-selected study models and 52 unbiased observers. Benzécri's correspondence analysis showed Dahlberg's classification to be the most confidently applied. Observers showed less confidence in the application of individual class boundaries described by Goose and Lee; the methods of Alvesalo and Shapiro were the least confidently applied. Pair-wise Yates' chi-square tests on differences in left and right counts for each of the above methods indicated a significantly higher degree of antimeric classificatory consistency for the Dahlberg method.

Tooth morphology in Down's syndrome: evidence for retardation in growth.

Two dental morphological features, lower incisor shape and Carabelli trait on upper molars, were studied in Down's syndrome (DS) individuals and control groups. Lower incisors were smaller in DS in absolute terms, but showed a relatively greater mesiodistal crown dimension than labiolingual, the opposite relationship to normal. Although the Carabelli trait was present in a high percentage of DS subjects, few showed the cuspal form. These findings are consistent with the concept of a reduction of cellular activity of tooth germs reflecting a general retardation in growth in DS. The altered shape of the lower incisors may influence the pattern of periodontal disease observed in DS subjects.

Dental morphology and odontometry of the Tibetan immigrants.

Dental features such as size, shape, cusp number and groove pattern, deflecting wrinkle, protostylid, form and size of dental arch and occlusion pattern, as well as crown diameters of maxillary and mandibular dentition of the Tibetan immigrants in India are described. Sex differences in various measurements are also noted. Overall reduction in size, presence of hypodontia of the third molar, and absence of Carabelli's trait are a distinct progressive/evolutionary trend in the Tibetan dentition, while presence of a shovel-shaped lingual surface of central and lateral incisors is a retrogressive/primitive condition. In some of the dental features Tibetans resemble Caucasoid and modern populations, in certain others they resemble other Mongoloid populations, and in still other features they resemble aboriginal populations and fossil hominids.

Human Dental Remains From Early Neolithic Levels at Mehrgarh, Baluchistan

Previous articleNext article No AccessResearch ConclusionsHuman Dental Remains From Early Neolithic Levels at Mehrgarh, BaluchistanJohn R. LukacsJohn R. Lukacs Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 24, Number 3Jun., 1983 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/203015 Views: 4Total views on this site Citations: 13Citations are reported from Crossref Copyright 1983 The Wenner-Gren Foundation for Anthropological ResearchPDF download Crossref reports the following articles citing this article:Sujitha P, R. Bhavyaa, Muthu M S, Latha Nirmal, Sneha S. Patil Crown dimensions of primary teeth—A systematic review and meta‐analysis, Journal of Forensic Sciences 67, no.44 (Mar 2022): 1348–1356.https://doi.org/10.1111/1556-4029.15015Hameem Bin Hameed, Yousaf Ali, Amin Ullah Khan Regional Development through Tourism in Balochistan under the China-Pakistan Economic Corridor, Journal of China Tourism Research 18, no.11 (Jul 2020): 1–19.https://doi.org/10.1080/19388160.2020.1787910Bahata A. Mukhopadhyay Metal-smithy, Bead-making, Jeweler’s weight, Trade-permit, Tax-stamp: Indus Script’s Semasiography Partly Decoded, SSRN Electronic Journal 2 (Jan 2021).https://doi.org/10.2139/ssrn.3778943Bahata Ansumali Ancient Tax Tokens, Trade Licenses and Metrological Records?: Making Sense of Indus Inscribed Objects Through Script-Internal, Contextual, Linguistic, and Ethnohistorical Lenses., SSRN Electronic Journal (Jan 2018).https://doi.org/10.2139/ssrn.3189473Kenneth A.R. Kennedy Paleoanthropology of South Asia, Evolutionary Anthropology: Issues, News, and Reviews 8, no.55 (Jan 1999): 165–185.https://doi.org/10.1002/(SICI)1520-6505(1999)8:5<165::AID-EVAN5>3.0.CO;2-0Kurt W. Alt, C. Loring Brace, Jens C. Türp The History of Dental Anthropology, (Jan 1998): 15–39.https://doi.org/10.1007/978-3-7091-7496-8_3John R. Lukacs Dental paleopathology and agricultural intensification in South Asia: New evidence from Bronze Age Harappa, American Journal of Physical Anthropology 87, no.22 (Feb 1992): 133–150.https://doi.org/10.1002/ajpa.1330870202Kenneth A. R. Kennedy Skeletons in the Closet: Recent Recovery of Lost Human Remains from Iron Age Raigir, Andhra Pradesh, South Asian Studies 6, no.11 (Jan 1990): 201–226.https://doi.org/10.1080/02666030.1990.9628412Roberto Macchiarelli Prehistoric “fish-eaters” along the eastern Arabian coasts: Dental variation, morphology, and oral health in the Ra's al-Hamra community (Qurum, Sultanate of Oman, 5th-4th millennia BC), American Journal of Physical Anthropology 78, no.44 (Apr 1989): 575–594.https://doi.org/10.1002/ajpa.1330780411C. Loring Brace, Karen R. Rosenberg, Kevin D. Hunt GRADUAL CHANGE IN HUMAN TOOTH SIZE IN THE LATE PLEISTOCENE AND POST-PLEISTOCENE, Evolution 41, no.44 (May 2017): 705–720.https://doi.org/10.1111/j.1558-5646.1987.tb05847.xKenneth A. R. Kennedy, Siran U. Deraniyagala, William J. Roertgen, John Chiment, Todd Disotell Upper pleistocene fossil hominids from Sri Lanka, American Journal of Physical Anthropology 72, no.44 (Apr 1987): 441–461.https://doi.org/10.1002/ajpa.1330720405Kenneth A. R. Kennedy, John Chiment, Todd Disotell, David Meyers Principal-components analysis of prehistoric South Asian crania, American Journal of Physical Anthropology 64, no.22 (Jun 1984): 105–118.https://doi.org/10.1002/ajpa.1330640203John R. Lukacs Dental Anthropology of South Asian Populations: A Review, (Jan 1984): 133–157.https://doi.org/10.1007/978-1-4899-5001-7_7

The influence of crown size dimorphism on sex differences in the Carabelli trait and the canine distal accessory ridge in man

When the two sexes were contrasted, Pima Indian males showed larger crown dimensions and more pronounced expressions of two morphologic variables, the Carabelli trait and the lower canine distal accessory ridge. In addition, a significant positive relationship was found between crown size and degree of expression of the morphologic traits. When regression analysis was utilized to control for male-female tooth size differences, the moderate dimorphism shown by Carabelli trait was reduced by about half. The more dimorphic distal accessory ridge, related primarily to mesio-distal diameter, also showed a lesser sex difference when crown size effects were held constant. While size dimorphism does contribute to morphologic dimorphism, factors unrelated to crown size still contribute the majority of variance present in trait expression both within and between sexes.

Developmental patterns of human dental morphological traits

A longitudinal series of casts of the deciduous and permanent dentitions of 827 children from the Burlington Growth Centre study was examined for 5 traits: shovel-shape of the incisors, cusp six, cusp seven and protostylid of the mandibular molars, and Carabelli trait of the maxillary molars. The changing trait frequencies found support the concept of morphogenetic gradients of expression for non-metric traits from deciduous to permanent teeth. Tests of association showed that if shovelling was present on the deciduous incisors it would usually appear on the permanent successors. Tests of association between the other 4 traits on deciduous second molars and the permanent molars support the view that the second deciduous molar belongs to the total molar tooth district. This gradient expression of morphological traits would fit either the field or clone concepts, but it, and the intra-individual discordances for trait presence, probably reflects the great temporal spacing of dental development seen in man.

The Carabelli trait in Australian Aboriginal dentition

Over 80 per cent of the subjects showed some form of the character in the deciduous dentition, about 10 per cent having cusps; in the permanent dentition, about 70 per cent of the subjects had the character, 20 per cent showing cusps. Sexual dimorphism was not evident in the deciduous dentition but, in the permanent dentition, the character was more common in males who also showed a higher degree of expression than females. Generally, the trait occurred bilaterally with symmetrical expression in both dentitions. Although the character was present in the deciduous dentition but not the permanent in a number of subjects, the reverse situation was rare. Comparisons between siblings of individuals with the character and siblings of individuals from the general population provided some evidence of a genetic basis to the character, but its heritability is probably low. Variations in phenotypic trait expression between sides, sexes and dentitions probably reflect the interplay between environmental influences and the timing of developmental processes.

Complex segregation analysis of Carabelli's trait in a Melanesian population.

A complex segregation analysis was performed on Carabelli's trait on the upper first molar utilizing 358 nuclear families from the Solomon Islands of Bougainville and Malaita. Simultaneous estimation of three sources of variation by the method of maximum likelihood demonstrates a significant effect of shared sibling environment which accounts for over 19% of the variance in liability for the trait. In addition, a statistically significant major gene influence is discussed and suggestions for quantifying individual liability levels for this and other dental traits are outlined.

Dental Condition of Two Tribes of Taiwan Aborigines-Ami and Atayal

This is a study of dental and oral conditions of Taiwan aborigines from the epidemiological and anthropological points of view. A total of 166 Ami and 128 Atayal adolescents were included from their original living area, the Hwa-Lien Hsin and Wa-Lai District, Taiwan, Republic of China. Oral examination was done carefully and caries incidence, periodontal index, and Angle's Classification combined with OFI were included. After that, hydrocolloid impressions were taken, and dental casts were immediately made. The mesiodistal and buccloingual crown diameters and also the arch depth and width were measured using a sliding caliper. Dental morphological traits, such as shovel-shaped incisors, Carabelli's cusp, protostylid, and upper and lower molar groove patterns were observed and classified, and the results are given with statistical analysis. The aborigines have a quite low incidence of dental caries and periodontal disease which may be related to their dietary habits, good oral hygiene, and good dental occlusion. With regard to the differences between the Ami and Atayal, most of the date show no statistical significance except in the dental occlusion. The Atayal's occlusion is better than that of the differences of genetics or other factors. There are no sex differences in all the date in the dental survey, but there are sex differences in both the misiodistal and buccolingual crown diameters of both the Ami and Atayal tribes (the tooth crown of the male subjects is invariably broader and larger than that of females). In the dental arch dimensions, most of the data show no sex diffreence, except in the breadth of the upper and lower dental arch of the Atayal. Anthropologically, there are no statistical differences, in mesiodistal and buccolingual crown diameters and most of the data of dental arch dimesions, but there is a difference in arch depth in Ami and Atayal adolescents. The Atayal have a deeper dental arch than do the Ami. As for dental morphologi, the Taiwan aborigines have a high frequency of shovel-shaped incisors and Carabelli's trait but a relatively low frequency of protostylid. There are no definite differences between races in the occlusal pattern of maxillary first molars, but there are differences in the maxillary second molars. The usual pattern is 4-- for the upper first and second molars of the Taiwan aborigines as well as for thedibular occlusal pattern, the first molar tends to follow the primitive "dryopithecus" pattern of 5 cusps and Y configuration, but in the second molar there are varying degrees of departure from Y5 to the more advanced +4 pattern with +5 and Y4 as intermediates.

Genetic structure of a tribal population, the Yanomama Indians. XIII. Dental microdifferentiation.

Data are presented on the frequency of the following eight dental traits in 635 Yanomama and 65 Makiritare Indians: upper central incisor rotation or winging, shoveling of maxillary incisors, maxillary molar hypocone reduction, Carabelli's trait, mandibular molar cusp number, mandibular molar cusp pattern rotation of second lower premolar, and pattern of second lower premolar cusps. Yanomama dentition is unusual in the high frequency of six cusps on the mandibular molars. There is marked dental microdifferentiation between villages; significant agreement was observed between a matrix of pairwise "dental distances" based on six morphological traits and corresponding matrices based on 11 genetic systems and on geographic location.

Carabelli's trait on maxillary second deciduous molars and first permanent molars in Hindus

The maxillary casts of 211 Gujarati Hindu children were examined for the occurrence of Carabelli's trait on the maxillary second deciduous molar (dm 2). The trait was absent in 11.8 per cent. The tubercle form was present in 19.9 per cent and groove and pit in 58.3 per cent and 7.8 per cent respectively. The trait was usually present bilaterally. A further study of 192 dental casts out of 211 showed that the trait was present on the dm 2 if it was present on M 1 with a statistical significance at 5 per cent level.

Heritability of the Carabelli cusp in twins.

The study of the Carabelli trait among 199 monozygotic and dizygotic twin pairs failed to demonstrate a high degree of heritability. Analyses of antimere differences in individuals indicated a lack of mirroring and no sexual dimorphism. Monozygotic twin pairs exhibited a higher concordance rate for corresponding tooth comparisons than dizygotic twin pairs.

Carabelli's trait in Hindu children from Gujarat.

Occurrence of different forms of Carabelli's trait on the maxillary first permanent molar was studied in 489 Hindu children from Gujarat. The trait was absent in 35.4% of the teeth studied. Groove form was observed most commonly. Slight tubercles were found more often than pronounced tubercles, and more tubercles were found in boys than in girls; conversely, absence of this trait was observed more often in girls than boys.

The relationship between Carabelli's trait and the size, number and morphology of the maxillary molars

The Carabelli trait is a dental feature that forms along the lingual margin of the protocone of deciduous and permanent maxillary molars. It is variably expressed, ranging from a small pit or furrow to a large cusp, and its development seems to be associated with crown size and molar cusp spatial configuration. The degree of expression of the Carabelli trait differs systematically between hominin taxa, and for this reason, it has been used extensively in the reconstruction of their phylogeny. However, the functional implications of having a large Carabelli trait remain unclear. In this study, we analyze the macrowear pattern of maxillary molars of early and late hominins using the occlusal fingerprint analysis method, an approach based on digital models of teeth that helps in reconstructing occlusal dynamics occurring during mastication. Tooth crowns with a small Carabelli cusp generally exhibit larger wear contact areas that extended cervically, while two additional new occlusal contact areas are common in teeth characterized by a large Carabelli cusp. These wear areas are created at the beginning of the chewing cycle, when occluding with the slopes of the lingual groove of the lower molars, between the metaconid and entoconid cusps. Advancing tooth wear leads to a slight enlargement of Carabelli occlusal contacts increasing their functional area. A steep inclination could be mechanically important in food reduction and in balancing the functional load distribution during mastication contacts. Steep wear areas are particularly developed in primates that process foods characterized by tough and fibrous textural properties. Future biomechanical and microwear texture analyses could provide additional information on the mechanical adaptation of this dental trait.

Genetic independence of Carabelli's trait from tooth size or crown morphology

Genetic independence of Carabelli's trait from tooth size or crown morphology