首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A study of coastal and inland Alaskan Eskimos revealed that a faintly developed Carabelli's cusp was present in 42.7%. No sex difference in the occurrence of Carabelli's cusp was evident and no family showed any difference in the distribution of the frequencies when each family was compared to the rest of the population. A general tendency toward a higher prevalence of Carabelli's cusp in the coastal Eskimos may be due to more admixture with white people along the coast. Alaskan Eskimos have a significantly higher frequency of Carabelli's cusp than do Aleuts. Statistical evaluation revealed that in the Alaskan Eskimo dentition the formation of Carabelli's cusp is independent of the size of the molars and the suppression of the third molars.  相似文献   

2.
Observations on morphological characters of milk and permanent teeth, based on 648 pairs of dental casts of 356 male and 292 female Jat children of Haryana (India) are reported. Deciduous teeth show high frequencies of bilateral winging of maxillary central incisor, Carabelli's cusp of maxillary second molar, and deflecting wrinkle of mandibular second molar. Reduction of maxillary molar cusps is more marked in males than in females. Y pattern is very common in deciduous molars. Permanent teeth have high frequencies of grooved cingulum of incisors, cingular nodule of lateral incisors and canines, and distal accessary ridge of canines. Low frequencies of Carabelli's cusp and winging are also common. The tendency towards faintly developed shovelling in milk incisors occurs more often than in the permanent teeth.  相似文献   

3.
Dental characteristics were studied on 60 skulls that belong to a population of Diaguitas Indians of approximately the Tenth Century. Mesiodistal crown diameters of permanent teeth were as follows: central incisors (8.77 mm), lateral incisors (7.23 mm), canines (8.40 mm), first maxillary molars (10.77 mm), second maxillary molars (10.71 mm), first mandibular molars (11.13 mm), and second mandibular molars (10.17 mm). Also determined was the frequency of shovel shaped incisors (80.30%), groove and cusp patterns of mandibular molars (Y5 73.40%), groove and cusp patterns of maxillary molars (H4 87.25%), and mesiopalatal version of maxillary incisors (66.20%). No skull showed Carabelli's cusp. The findings were compared with those for different populations past and living. The results suggest that the affiliation of the population analyzed was mongoloid.  相似文献   

4.
Clinical examination of the teeth and the mouth was carried out on a group of 133 "Old Believers," 54 males and 79 females, and a control group of 138 Poles living in the same area of Augostova in northeast Poland, 63 males and 75 females. Studying the frequency of Carabelli's cusp, shovel-shaped incisors, missing teeth, microdonita, supernumerary teeth, and torus palatinus in both groups, it was found that Carabelli's cusp and torus palatinus are more frequent among Poles. Such differences could be attributed to differences in ethnic origin of the two groups.  相似文献   

5.
6.
Odontometric and morphologic observations were made of the dentition of skeletal remains of Australian aborigines from Boradbeach, S.E. Queensland. Tooth size, especially of the molars, was found to be significantly larger than that reported for other recent Aboriginal populations. Tooth morphology also differed, with a higher frequency of five cusped second molars, and a lower frequency of shoveling and Carabelli's cusp than previously reported as typical of Australian aborigines.  相似文献   

7.
A sample of 192 male propositi with at least one ULI either missing or reduced has been compared with 197 male controls in terms of the morphology of the other teeth. Every class of propositi exhibits modifications in the following characters: Significant differences between propositi and controls were found for molar cusp number and groove pattern, particularly in the lower first molar and in propositi with reduced ULI. Significant differences between propositi and controls were also found with respect to caniniform pattern of the lower first premolar. The Carabelli's cusp is rarer in propositi. A hypothesis to account for these observations is proposed.  相似文献   

8.
Mongoloid populations differ from Caucasoids by having a high prevalence of shovel trait and a low prevalence of Carabelli's trait. This study was conducted to investigate the effects of the shovel trait on Carabelli's trait in a Mongoloid population. The research design sought a population that resides in an isolated area and exhibits low admixture with neighboring populations. The Mongoloid group selected for study was the Bunun tribe of aborigines who inhabit an alpine area in Taiwan. The effects of sex and age on Carabelli's trait were controlled in this investigation, as was the association between tooth size and Carabelli's trait. Results show that males were more likely to have Carabelli's trait expressed on teeth than females. The buccolingual diameter of Carabelli's trait teeth was larger than that of teeth without the trait. After adjusting for sex, age, and tooth size, the existence of the shovel trait increased the likelihood of having Carabelli's trait by a factor of three, an effect that is significant. © 1996 Wiley-Liss, Inc.  相似文献   

9.
Examination for incidence of Carabelli's trait was done on 1267 Africans and 781 Asian school children, 298 dental plaster casts and 248 skulls of Africans. The African sample is composed of 80% Bantu, 20% Nilote, and Nilo-Hamitic people. When observed intraorally, the trait is present in 31–35% of Africans and 26–27% of Asians. In the dental casts and skull sample of Africans, the trait is present as pit in 23–28%, groove in 20%, and as tubercle and cusp in 22%. The total trait frequency in Africans is 68%.  相似文献   

10.
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.  相似文献   

11.
Fourteen morphologic crown traits were observed in a sample of 1528 Pima Indians of south-central Arizona. Pima dentitions are characterized by high frequencies of shoveling, incisor winging, the hypocone, the lower canine distal accessory ridge, cusp 6, and the protostylid. They exhibit low frequencies of the metaconule and lower premolar multiple lingual cusps and moderate frequencies of the canine tubercle, Carabelli's trait, cusp 7, and lower second molars with four cusps and X groove patterns. When Pima crown trait frequencies were compared to those of 13 Southwest Indian samples, their closest affinities were to other Uto-Aztecan groups, the Papago and Hopi. The Pima are most divergent from Athapaskans and are also clearly removed from Yuman speaking groups and the Zuni. In general, the pattern of dental morphologic variation in the Southwest corresponds closely to linguistic divisions.  相似文献   

12.
Talon cusps are rare morphological features of the anterior dentition that represent a spectrum of lingual cingulum diversity. In this paper, talon cusp prevalence is described in two Archaic period North American samples, Windover Pond (Florida) and Buckeye Knoll (Texas). Given the early date of these cemeteries (~7500 BP), these specimens represent the oldest reported cases of lingual talon cusp in the New World, and perhaps globally. Windover preserves three cases of talon cusp (representing three different individuals) affecting the permanent maxillary lateral incisors. The sample frequencies were 1.8% and 3.1% for the left and right maxillary lateral incisors, respectively. Buckeye Knoll preserves four cases of talon cusp representing three individuals. Talon cusps at this site were distributed throughout the maxillary anterior dentition, including a permanent maxillary central incisor, bilateral permanent maxillary lateral incisors, and a deciduous maxillary lateral incisor. The multicomponent nature of this site complicates sample frequency calculation with by-tooth estimates ranging from 3.6% to 25%. This paper discusses the difficulties with comparative frequency estimation, resulting from a proliferation of terminology that is discipline-specific. Understanding the evolutionary basis and significance of dental morphological variation requires an inclusive approach to the comparative literature that focuses on homology within the context of odontogenetic process.  相似文献   

13.
1981年发现的安徽和县猿人化石   总被引:2,自引:4,他引:2  
吴茂霖 《人类学学报》1983,2(2):109-205
本文记述1981年在安徽和县发现的人的五枚牙齿化石、额骨眶上部残片及顶骨残片一块。研究表明,大多数形态特征与北京猿人非常相似,但也有较北京猿人进步的特征。和县猿人无疑地属直立人(Homo erectus),和县猿人的门齿与元谋猿人的门齿,在形态特征上存在较大的差别。  相似文献   

14.
Since Mivart (1865), Cacajao, Chiropotes, and Pithecia have been grouped into a single taxon, which he called the subfamily Pitheciinae but which I, following Rosenberger (this issue), refer to as the living members of the tribe Pitheciini. While few today doubt the association of these three living genera, not all would place them together with Aotus and Callicebus in the subfamily Pitheciinae. This is an attempt to sort out the behavioral and morphological features of feeding and dental morphology in these taxa. Extant members of the tribe Pitheciini are adapted for sclerocarpic foraging, morphological evidence for which is found in the fossils of Soriacebus and Cebupithecia. Sclerocarpic foraging in living pitheciins is a two-stage process of seed predation involving 1) specialized features of the anterior dentition that allow removal of a hard pericarp that protects a seed or seeds, followed by 2) mastication by the posterior dentition having low cusp relief to triturate nutritious seeds of a relatively soft and uniformly pliable consistency. The dentitions of fossil pitheciins, Soriacebus and Cebupithecia, demonstrate that the hypertrophy of lower incisors plus the robustness and flaring of the canine precede development of low cusp relief on molars and premolars in the evolution of morphological features associated with sclerocarpic foraging. Features of sclerocarpic foraging are found less uniformly in the other two pitheciines, Callicebus and Aotus.  相似文献   

15.
The objectives were to determine the expression frequency and sexual dimorphism of 16 non-metric crown traits on the sample of permanent dentitions of the living Druze population (a Near Eastern genetic isolate) in Jordan, and to assess the biological affinity of this sample to 21 regional groups, and to the living general Jordanian population, based on these traits. Druze schoolchildren (46 males, 40 females; mean age = 16.0, sd = 0.5 years) were studied in 2011. The traits were classified using the Arizona State University dental anthropology system, counted with the individual count method, and dichotomized according to the criteria of Scott and Turner for the purpose of group comparisons. Fisher's exact test for dichotomized scores was used to assess sexual dimorphism in these traits. Smith's mean measure of divergence was used to measure all pairwise distance values among the groups. Sexual dimorphism was found in five traits (i.e., UI2 interruption grooves, 3-cusped UM2, UM1 Carabelli's tubercle/cusp, 4-cusp LM1, and LM2 Y-groove pattern). This study revealed that the dental pattern of living Druze, which is similar to that of the general Jordanian population, is sufficiently distinct from the Western Eurasian pattern and all other known dental patterns to form a distinct dental pattern for the regional group or subcategory to which these two populations belong. Moreover, the relatively large distance values of the living Druze and Jordanians from the other world groups considered, including the Western Eurasian groups, suggest a similar major genetic difference of these two populations from the Western Eurasian ancestry.  相似文献   

16.
作者测量和观察了现代华南人1963个恒牙。结果表明,铲形上内侧门齿的出现率为91.8%;卡氏尖在M1中的出现率为23.8%,在M2中的出现率为1.6%。  相似文献   

17.
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 estiamtion 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.  相似文献   

18.
本文对广西罗泊湾出土的6个西汉初期殉葬人的口腔情况进行了观察和分析。发现这些个体的口腔主要特点是;对刃(牙合)比例高,各种腭型比例与现代壮族人相近,铲形门齿,智齿萌出率高,龋齿,牙周病罹患率不高,牙齿磨耗较重。  相似文献   

19.
Plaster casts of the dentition of 137 Bedouin, mostly members of the Abu Rabiya tribe in the Negev desert, were subjected to odontometric and morphologic analysis. They show a marked sexual dimorphism, very strongly developed maxillary and mandibular first molars and much reduced second molars. They exhibit the characteristics of middle-eastern populations with a rather weak expression of the shovel trait, upper premolars with relatively short BL diameters, a high prevalence of Carabelli's complex on the first maxillary molar and virtually complete absence of the protostylid. In general, the Bedouin have larger teeth than three other ethnic groups living in Israel whose dentitions have been recently investigated. Further similarities and differences are discussed.  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号