Palaeontology of the human dentition Part I. The crown patterns of fossil and recent human molar teeth and their meaning

Gregory, William K.; Hellman, Milo

doi:10.1016/s0099-6963(26)90166-x

Cited by 6 publications

(10 citation statements)

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“…molars. This cusp occurs not only in modern human populations but also in fossil hominids (Gregory and Hellman, 1926;von Koenigswald, 1952b) and nonhuman hominoids (Selenka, 1898). Sakuma and Ogata (1987) demonstrated that the seventh cusp occurs more frequently in Africans than non-Africans.…”

Section: Sixth Cusp: Lm1mentioning

confidence: 99%

Dental perspectives on the population history of Southeast Asia

Matsumura

Hudson

2005

Am. J. Phys. Anthropol.

105

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This article uses metric and nonmetric dental data to test the "two-layer" or immigration hypothesis whereby Southeast Asia was initially occupied by an "Australo-Melanesian" population that later underwent substantial genetic admixture with East Asian immigrants associated with the spread of agriculture from the Neolithic period onwards. We examined teeth from 4,002 individuals comprising 42 prehistoric and historic samples from East Asia, Southeast Asia, Australia, and Melanesia. For the odontometric analysis, dental size proportions were compared using factor analysis and Q-mode correlation coefficients, and overall tooth size was also compared between population samples. Nonmetric population affinities were estimated by Smith's distances, using the frequencies of 16 tooth traits. The results of both the metric and nonmetric analyses demonstrate close affinities between recent Australo-Melanesian samples and samples representing early Southeast Asia, such as the Early to Middle Holocene series from Vietnam, Malaysia, and Flores. In contrast, the dental characteristics of most modern Southeast Asians exhibit a mixture of traits associated with East Asians and Australo-Melanesians, suggesting that these populations were genetically influenced by immigrants from East Asia. East Asian metric and/or nonmetric traits are also found in some prehistoric samples from Southeast Asia such as Ban Kao (Thailand), implying that immigration probably began in the early Neolithic. Much clearer influence of East Asian immigration was found in Early Metal Age Vietnamese and Sulawesi samples. Although the results of this study are consistent with the immigration hypothesis, analysis of additional Neolithic samples is needed to determine the exact timing of population dispersals into Southeast Asia.

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Section: Sixth Cusp: Lm1mentioning

confidence: 99%

Dental perspectives on the population history of Southeast Asia

Matsumura

Hudson

2005

Am. J. Phys. Anthropol.

105

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“…6 Phenotypically, the mandibular occlusal groove pattern and the number of cusps were classified by Gregory and Hellman. 11 The key occlusal groove form "+4" was explained as four cusps with + shaped occlusal groove pattern, corresponding to Hellman's classification. 11 Among the five cuspal occlusal configuration the distobuccal cusp or the hypoconulid is the most evolved type and the fifth cusp disappears leading to a fourcusp form.…”

Section: Figure-1 Frequency Distribution Of Occlusal Characteristicsmentioning

confidence: 99%

“…11 The key occlusal groove form "+4" was explained as four cusps with + shaped occlusal groove pattern, corresponding to Hellman's classification. 11 Among the five cuspal occlusal configuration the distobuccal cusp or the hypoconulid is the most evolved type and the fifth cusp disappears leading to a fourcusp form. 12,28 Almost all of the studies relating to morphology of mandibular molars have used Hellman's classification.…”

Section: Figure-1 Frequency Distribution Of Occlusal Characteristicsmentioning

confidence: 99%

“…8,9 Racial and ethnic variations in the dimensions of mandibular molars alongwith their occlusal patterns present as identifying and distinguishing characteristics in forensic odontology and paleontology. 10 The multiple occlusal characteristics of mandibular second molars are evident as "5 -Y," " 4 -Y " , " +5 " and " +4 "s. [11][12][13] The future occlusal groove patterns is determined by the coalescence of hypocone with metacone resulting in either "Y" or a "+".…”

Section: Introductionmentioning

confidence: 99%

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Permanent Mandibular Second Molars

Ansari

Shaikh

Zaidi

et al. 2018

TPMJ

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Objectives: Tooth morphology plays an important role in dental anthropology& forensic odontology. This study was conducted to determine the frequencies of variationsin occlusal surface patterns in permanent mandibular second molars in a subset of Pakistanipopulation. Data Source: 500 medical and dental students of Dow University of Health Sciencesand healthy volunteers visiting the dental OPD with age range from 17 to 25 years. Design ofStudy: Cross-sectional analytical Study. Setting: Department of Oral Biology, Dr. IshratulIbadKhan Institute of Oral Health Sciences, Dow University of Health Sciences. Period: May 2017till August 2017. Materials & Methods: This analytical study was conducted in the departmentof Oral Biology at Dr Ishratul Ibad Khan Institute of Oral Health Science. Five hundred dentalcasts after interoral exam and impression taking were studied for the variations in the frequencyof of cusps and their relative groove and fissure pattern. Statistical analysis was performed byDescriptive analysis and Chi Square. Results: Out of the fivbe hundred casts that were analysed,51% were of males and 49% were of females. The four-cusped variety of mandibular molars withpresence of distal fovea and distal marginal ridge was the most frequent (95.4%) while the mostprevalent occlusal groove form was “+” shape (88.4%). Frequently present occlusal patternwas the “+4” form (85.4%). Conclusion: The occlusal configurations of mandibular molarsshowed high degree of variability. The most frequently occurring pattern of occlusal surface ofmandibular second molars in this subset of Pakistani population was determined to be “+4”form. These findings can be used for forensic, teaching & clinical purposes by providing aPakistani database for morphological characteristic of mandibular molars.

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“…The cusps and grooves on mandibular molars were subsequently investigated by Gregory and Hellman. [ 6 ] Gregory and Hellman[ 6 ] and Hellman[ 7 ] described variations in occlusal surfaces of the mandibular molars and developed morphological categories as “5 Y,” “5+,” “4Y” and “4+.” And Takeshi Matsuda has used “6Y,” “5Y,” “4Y,” “6+,” “5+,” “4+,” “6X,” “5X,” “4X” pattern for mandibular molars. Al most all dental anatomy textbooks describes permanent mandibular first molar as “Y” groove pattern with 5 cusp numbers and permanent mandibular second molar as “+” groove pattern and 4 cusps.…”

Section: Introductionmentioning

confidence: 99%

Occlusal morphology of permanent mandibular first and second molars in Gujarati population

Dholia

Manjunatha

2015

J Forensic Dent Sci

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Background:Dental identification has been used since long time for disaster victim identification protocol. There is a difference of opinion regarding whether ethnicity influences dental morphology or not. Few studies have shown the associations between these dental features and crown traits in humans using quantitative methods. The present study is an attempt to find correlation of occlusal morphology of Gujarati population with forensic Odontology.Aim:To study different occlusal morphology of permanent mandibular first and second molars in Gujarati Population.Materials and Methods:This study comprised of a total of 100 participants of Gujarati origin, selected by random sampling method. Total number of cusps and groove patterns of mandibular first and second molar were examined clinically and photographs of the same were taken. A descriptive statistics, Chi-square test and Student t-test were used for analysis of data.Results:Mandibular first molar with 5 cusps in 71%, 4 cusps in 18% and 6 cusps in 11% were noted in the study. Mandibular first molars with “+” groove pattern in 39.5% and “Y” groove pattern in 60.5% were recorded. Mandibular second molar with 5 cusps in 6.5% and 4 cusps in 93.5% were recorded in the study. Mandibular second molars with “+” groove pattern in 93.5% and “Y” groove pattern in 6.5% were recorded.Conclusion:The most common occlusal morphology in permanent mandibular first molar is “5 cusp” and “Y” groove pattern in about 47% and for second molar is “4 cusp” and “+” groove pattern in 88.5% of Gujarati population. It may be concluded that variation in degree of expression and frequency of teeth in dentitions of different populations is different, which may help in forensic identification.

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Palaeontology of the human dentition Part I. The crown patterns of fossil and recent human molar teeth and their meaning

Cited by 6 publications

References 0 publications

Dental perspectives on the population history of Southeast Asia

Dental perspectives on the population history of Southeast Asia

Permanent Mandibular Second Molars

Occlusal morphology of permanent mandibular first and second molars in Gujarati population

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