Dental anomalies and dental variations in the red foxVulpes vulpes in the Czech Republic

Dental abnormalities including polydonty, oligodonty, extra roots, different root morphotype, root fusion, different crown morphotype, crown reduction, partial crown eruption, supernumerary cusp, irregularities in the position of the teeth, and malocclusion were studied in a set of 785 red foxVulpes vulpes (Linnaeus, 1758) skulls (401 males, 273 females, and 111 individuals of unknown sex) from the Czech Republic. Three hundred sixty one cases of deviations from normal were found in 170 specimens (21.7%). Most of the deviations were variants within a genetically determined range. The prevalent dental variants included an extra root of M¹ (5.7% specimens), and different root morphotype of P₁ (1.9% specimens). On the other hand, the real dental anomalies, eg polydonty, occurred seldom within the population. P₁ ¹ and M₃ were missing significantly more frequently among females than among males unlike the other deviations, which were divided equally between the sexes. No differences were found between the left and right side of the jaw. Irregularities in the position of the teeth and oligodonty (excluding P¹ ₁, M₃) appeared significantly more abundantly on mandible, whereas extra roots and polydonty were more common on the maxilla. There was no relationship between the incidence of dental abnormalities and the relative mandible and rostrum length.     

Dental anomalies in the gray foxUrocyon cinereoargenteus and the red foxVulpes vulpes

We examined dental anomalies, including oligodonty, polydonty, connation, rotation, and misalignment in 510 gray foxes and 150 red foxes from southern Illinois (USA). Dental anomalies were significantly more common (x ² = 11.5, df = 1,p < 0.001) in gray foxes (n = 177; 34.7% of sample) than red foxes (n = 25; 16.6% of sample), and more common in male than female gray foxes (x ² = 3.88, df = 1,p < 0.05). Polydonty was very uncommon, as expected for species in which the normal dental complement is close to the primitive eutherian number. In both species, the most prevalent anomaly was loss of the last lower molar. Loss of the upper or lower first premolar was also common. Thus, oligodonty almost always involved the smaller anterior (P¹ and P₁) or posterior (M₃) teeth of the dental arcade. Conversely, the large carnassial teeth, with complex occlusal patterns and shearing surfaces, appeared to be highly conserved with only three anomalous individuals (0.4%) among all specimens.     

Dental anomalies in wild and domestic<Emphasis Type="Italic">Sus scrofa</Emphasis> in Illinois

The cleaned skulls of 39 wild and 30 domestic pigs from southern Illinois (USA) were assessed for dental anomalies including polydonty, oligodonty, misalignment, and rotation. Dental anomalies occurred in 16 wild and 15 domestic pigs. Oligodonty (either bilateral or unilateral) was the most common anomaly, occurring in 9 wild (23.1% of the sample) and 15 (50%) domestic pigs. In 22 of the 24 individuals exhibiting oligodonty, this anomaly involved the lower first premolar (P₁). Given the placement of P₁, oligodonty may reflect a trend toward reduction of the dental arcade from the primitive eutherian number. Domesticated species are reported to have more anomalies than wild counterparts because of inbreeding. We found no difference in the number of dental anomalies between domestic and wild pigs.     

Metrical dental analysis on golden monkey (Rhinopithecus roxellana)

Dental variation in the Chinese golden monkey (Rhinopithecus roxellana) is here evaluated by univariate, bivariate, and multivariate analyses. Allometric analyses indicate that canines and P3s are positively, but other dimensions negatively scaled to mandible and maxilla, and to body size. With the exception of the mesiodistal dimensions of I₁ and M₃, and the buccolingual dimension of P₄, mandibular dental variables show similar scaling relative to body size. Analysis of residuals shows that males have significantly larger canine, P³ and buccolingual dimensions of the postcanine teeth (M² and M³) than females. A significant difference in shape between the sexes is found in the buccolingual dimension of the upper teeth, but not in the mandible. Unlike the situation in some other species, female golden monkeys do not exhibit relatively larger postcanine teeth than males. In fact, the reverse is true, expecially for M²s and M³s. The fact that most of the dental variables show low negative allometry to body size might be related a cold environment that has led to the development of larger body size with reduced energy loss. When the raw data are examined by Discriminant Function Analysis the sexes are clearly distinguishable.     

Dental wear among cercopithecid monkeys of the Taï forest,Côte d'Ivoire

Studies of dental macrowear can be useful for understanding masticatory and ingestive behavior, life history, and for inferring dietary information from the skeletal material of extinct and extant primates. Such studies to date have tended to focus on one or two teeth, potentially missing information that can be garnered through examination of wear patterns across the tooth row. Our study measured macrowear in the postcanine teeth of three sympatric cercopithecid species from the Taï Forest, Côte d'Ivoire (Cercocebus atys, Procolobus badius, and Colobus polykomos), whose diets have been well‐described. Inter‐specific analyses suggest that different diets and ingestive behaviors are characterized by different patterns of wear across the molar row, with Cercocebus atys emphasizing tooth use near P₄‐M₁, P. badius emphasizing a large amount of tooth use near M₂‐M₃, and Colobus polykomos exhibiting wear more evenly across the postcanine teeth. Information regarding differential tooth use across the molar row may be more informative than macrowear analysis of isolated teeth for making inferences about primate feeding behavior. Am J Phys Anthropol 150:655–665, 2013. © 2013 Wiley Periodicals, Inc.     

Characterization of gene pools of three <Emphasis Type="Italic">Pinus pumila</Emphasis> (Pall.) Regel populations at the range margins

Genetic variation of Siberian dwarf pine Pinus pumila (Pall.) Regel was characterized in three marginal populations in southwestern, southern and eastern parts of the natural species range (Baikal Area, Primorye, Kamchatka) using isozyme analysis. Analysis involving 16 isozyme loci encoding ten enzyme systems was conducted. Our results confirm that P. pumila is one of the most polymorphic species in the genus Pinus. Three marginal populations exhibited high genetic variation (P ₉₅ = 68.8%, H _o = 0.247, H _e = 0.291). Populations heterogeneity and significantly high level of divergence in coniferous (F _ST = 0.050, D _N = 0.044) reflect their genetic originality. In summary, it was shown that the level of genetic variation characteristic for P. pumila in other parts of the not only is reproduced in the populations examined but even is close to maximum there.     

Nouvelle méthode d’estimation de l’âge dentaire des Néandertaliens

Several authors have already observed the dyschronic growth between Neanderthals and modern Humans permanent teeth but they never quantified it. Dental maturation is the best and mostly used way to evaluate precisely the decease age of Neanderthals. We thus present here an extensive study realised with deciduous and immature permanent Neanderthals teeth, which lead us to propose a new mode! Of dental maturation allowing to estimate their age without using the classical modern populations dental growth tables. We propose two methods, one using two mathematical formulas, the other one using a new table, which permits to directly obtain the age of a Neanderthal from his deciduous and permanent teeth degree of maturation data.     

Accuracy of dental age estimation charts: Schour and Massler,Ubelaker and the London Atlas

Dental age estimation charts are frequently used to assess maturity and estimate age. The aim of this study was to assess the accuracy of estimating age of three dental development charts (Schour and Massler, Ubelaker, and the London Atlas). The test sample was skeletal remains and dental radiographs of known‐age individuals (N = 1,506, prenatal to 23.94 years). Dental age was estimated using charts of Schour and Massler, Ubelaker, and The London Atlas. Dental and chronological ages were compared using a paired t‐test for the three methods. The absolute mean difference between dental and chronological age was calculated. Results show that all three methods under‐estimated age but the London Atlas performed better than Schour and Massler and Ubelaker in all measures. The mean difference for Schour and Massler and Ubelaker was ?0.76 and ?0.80 years (SD 1.27 year, N = 1,227) respectively and for the London Atlas was ?0.10 year (SD 0.97 year, N = 1,429). Further analysis by age category showed similar accuracy for all three methods for individuals younger than 1 year. For ages 1–18, the mean difference between dental and chronological ages was significant (P < 0.05) for Schour and Massler and Ubelaker and not significant (P > 0.05) for the London Atlas for most age categories. These findings show that the London Atlas performs better than Schour and Massler and Ubelaker and represents a substantial improvement in accuracy of dental age estimation from developing teeth. Am J Phys Anthropol 154:70–78, 2014. © 2014 Wiley Periodicals, Inc.     

Relative contribution of caries and periodontal disease in adult tooth loss among patients reporting to the Institute of Dental Sciences,Belgaum, India

Objectives: To examine the reasons for tooth loss in an adult population. Methods: Patients who reported to the department of prosthodontics in Institute of Dental Sciences, Belgaum, located in the north‐western part of the state of Karnataka, in the southern region of India over a period of 2 months, with at least one missing tooth (excluding third molars) constituted the sample size. There were a total of 365 patients (185 females and 180 males) within the age group of 16–84 years (mean age 51.06 ± 16.47 years) who fulfilled this criterion. Socio‐demographic profile was recorded along with a clinical examination for assessing the number and pattern of tooth loss. The reasons for tooth loss were recorded according to the history reported by the patient. Results: In the present study of 365 patients, 58.9% of the patients were completely edentulous, 41% were partially dentate, of which 20.8% had lost their teeth from caries, 11% from periodontal disease and 9.3% from a combination of reasons. More females had lost their teeth because of dental caries whereas more males had lost their teeth because of periodontal disease, this being statistically significant. (χ² = 16.53, p = 0.001). Highly significant results were obtained for age and reasons for tooth loss. (χ² = 150.39, p < 0.001). Irrespective of the socio‐economic status, dental caries was the most common cause for tooth loss in partially dentate patients though it was not statistically significant (χ² = 13.62, p = 0.325). Mandibular first molars were the teeth most frequently lost due to dental caries. The maxillary left central incisor was most frequently lost due to periodontal disease, followed by the maxillary right central incisor. Conclusions: Since both dental caries and periodontal disease contributed to tooth loss at different ages, risk indicators need to be identified.     

Expression of cell cycle regulatory proteins in epithelial components of dental follicles

Dental follicle is a component of tooth germs, which remain adjacent to the crown of unerupted or impacted teeth. Under the influence of pathologic changes, however, dental follicles that possess reduced epithelium can proliferate into stratified squamous epithelium as far as originate dental cysts. In order to clarify the role of apoptosis and cellular proliferation herein, expression of p53 and PCNA was examined in epithelial components of dental follicles associated with impacted third molars by means of immunohistochemistry. A total of 40 cases was included in this study being 22 cases with reduced epithelium and 18 cases with stratified epithelium. Expression of p53 expression was weak or not detected in dental follicles with reduced and stratified squamous epithelium. By contrast, PCNA positive cells were evidenced in basal and supra basal layers of the stratified squamous epithelium and in reduced epithelium of dental follicles, but without any significant statistically differences between them (P > 0.05). In conclusion, these data suggest that dental follicles possess proliferative activity as depicted by PCNA-positive nuclei in some epithelial cells. However, the biological behavior of dental follicles during the late stage of dental eruptive process may not be associated with deregulation of death and/or cell proliferation.     

Using extant patterns of dental variation to identify species in the primate fossil record: a case study of middle Eocene <Emphasis Type="Italic">Omomys</Emphasis> from the Bridger Basin,southwestern Wyoming

Patterns of extant primate dental variation provide important data for interpreting taxonomic boundaries in fossil forms. Here I use dental data from several well-known living primates (as well as data from selected Eocene forms) to evaluate dental variation in Middle Eocene Omomys, the first North American fossil primate identified by paleontologists. Measurements were collected from a sample of 148 omomyid dental specimens recovered from Bridger B localities in the Bridger Basin, Wyoming. Most of these specimens have not previously been described. Nonmetric traits were also scored for this sample. Lower molar coefficients of variation range from 4.01 for M₂ length (n = 80) to 6.73 for M₃ talonid width (n = 57). All of the nonmetric traits scored exhibit less than 100% presence in the overall sample, including traits previously described as representative of Omomys (e.g., P₄ metaconids present in 91%, n = 55; M² pericones present in 80%, n = 15). Dental traits also vary in a set of spatially restricted localities from the same fossil horizon and in a separate, single fossil locality (DMNH 868, P₄ metaconids present in 67%, n = 6). An increasing frequency in several premolar traits across time in these more restricted samples suggests an anagenetic change in Bridger B Omomys. However, this degree of morphological variability is consistent with that seen in extant primate species from single locations. Metric variation in this sample is comparable to that seen in other Eocene primates, such as new data presented here for the omomyid Arapahovius gazini from the Washakie Basin, southern Wyoming. Omomys metric variation is also comparable to that found in several samples of well-known extant primates from single localities (e.g., ring-tailed lemurs and gray–brown mouse lemurs). These metric data also correspond to the patterns of variability described in previously published studies of Omomys carteri. In sum, a single species interpretation (O. carteri) for this new Bridger B Omomys sample from southern Wyoming is affirmed, and this study illustrates the usefulness of dental data from extant primates for evaluating primate fossil samples.     

Dental topography and diets of four old world monkey species

Dental topographic analysis allows comparisons of variably worn teeth within and between species to infer relationships between dental form and diet in living primates, with implications for reconstructing feeding adaptations of fossil forms. Although analyses to date have been limited mainly to the M₂s of a few primate taxa, these suggest that dental topographic analysis holds considerable promise. Still, larger samples including a greater range of species and different tooth types are needed to determine the potential of this approach. Here we examine dental topography of molar teeth of Cercocebus torquatus (n=48), Cercopithecus campbelli (n=50), Colobus polykomos (n=50), and Procolobus badius (n=50). This is the first such study of large samples of Old World monkeys, and the first to include analyses of both M₁s and M₂s. Average slope, relief, and surface angularity were computed and compared among tooth types, wear stages, and species. Results suggest that (1) data for M₁s and M₂s cannot be compared directly; (2) slope and relief decline with wear on M₂s of all taxa, and M₁s of the colobines, whereas angularity does not generally change except in the most worn specimens; and (3) folivorous colobines tend to have more sloping surfaces and more relief than do frugivorous cercopithecines, though angularity does not clearly separate taxa by diet. Am. J. Primatol. 71:466–477, 2009. © 2009 Wiley‐Liss, Inc.     

Microevolutionary trends in the dentition of the Red fox (Vulpes vulpes)

Microevolutionary trends in dental traits were studied in a Polish population of the Red fox, Vulpes vulpes (Linnaeus, 1758). Changes in qualitative and quantitative traits over a 70‐year interval were analysed in 1453 museum specimens collected between 1927 and 1996. Over that period, there were qualitative trends towards increasing complication of occlusal crown surface in posterior premolars (i.e. P⁴, P₃, P₄) and I³. Other cheek teeth did not undergo directional change. Changes in trait correlations were assessed using samples from the 1960s and 1990s. The correlations between C¹–C₁ and M¹–M² increased, while correlation values in the incisor region (I₁–I₂, I¹–I₁, I¹–I₂, I³–I₂), carnassial region (P₄–M₁, P⁴–M₁ and M₁–M₁) and in P²–P₁ decreased. These changes may be related to increasing dietary opportunism of the Red fox during the 20th century.     

Cranio-Mandibular Biometrics and Skull Maturation of Macaca sylvanus L., 1758

We report on the biometrics of cranial and dental features in 42 Macaca sylvanus specimens from various museums across Europe. Age classes were determined following dental criteria. Standard biometric landmarks were used to take 17 measurements on the cranium and five on the mandible. The permanent cheek dentition (except the whole C₁/C¹–P₃/P³ complex) was also recorded with four measurements for each molar tooth (three for the P₄/P⁴). Skull measurements show strong sexual dimorphism for characters tied to the mandibular and muzzle/facial portions. The unusual molar dimorphism of M. sylvanus is an unexpected result, because the Cercopithecoid molar pattern is often considered as generally conservative and not very dimorphic. A significant difference between M. sylvanus and other macaques also regards the absolute narrowing of the molar distal loph. This difference may result from a retained plesiomorphic condition, perhaps correlated with the less specialized and tougher diet maintained by M. sylvanus. A multivariate comparison for cranial (both sexual and ontogenetic) difference in M. sylvanus suggests that the full maturation of the male skull shape is delayed longer than what would be expected according to the most restrictive dental criteria adopted here for subadult/adult discrimination. The clustering results, indeed, indicate that significant phenetic differences persist between most of the male crania which are far advanced in their latest dental steps and those of the “fully developed adults”. Outcomes of final growth such as those observed in M. sylvanus suggest that polymorphic maturational patterns can mislead the assessment for a true adult skull shape.     

高速气涡轮切割手机联合专用加长裂钻对拔除下颌阻生第三磨牙的效果分析

目的:探讨牙科高速气涡轮切割手机配合阻生牙专用加长裂钻拔牙对口腔外科门诊需要拔除下颌阻生第三磨牙患者的影响。方法:选取我院收治的59例需要拔除下颌阻生第三磨牙患者,按照随机数字表法将所有患者随机分为试验组和对照组两组。其中试验组患者采用牙科高速气涡轮切割手机辅助阻生牙专用加长裂钻进行拔牙,而对照组患者则采取传统的劈骨分牙法,通过两组患者的术后复诊对患者的下唇麻木、断根等发生率以及张口受限、疼痛、肿胀等情况进行评价。结果:根据我院对两组患者的术中情况及术后并发症情况进行统计分析,结果显示试验组患者的手术时间为(25.68±6.83)min,明显低于对照组患者[(35.23±14.23)min,t=3.962,P=0.000]。试验组患者中仅有1例术后出现断根情况,无其他并发症出现;而对照组患者术后则有3例断根情况和1例下唇麻木患者(后逐渐缓解)、1例下颌关节疼痛以及1例舌侧骨板骨折患者。根据我院对两组患者术后1d的临床资料进行统计分析,结果显示试验组患者术后1d面部肿胀程度明显比对照组患者轻(P0.05);试验组患者的疼痛情况明显优于对照组患者(P0.05);试验组患者的张口受限程度明显比对照组患者轻(P0.05)。结论:牙科高速气涡轮切割手机配合阻生牙专用加长裂钻拔牙对口腔外科门诊需要拔除下颌阻生第三磨牙患者具有较好的临床治疗效果,值得在临床上加以广泛推广和运用。     

Estimation of the levels of radiation-induced <Emphasis Type="Italic">P</Emphasis>-element transposition in <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> experimental populations and laboratory strains

When experimental P + M populations were exposed to chronic γ-irradiation (0.31 mGy/h), the highest instability level of the singed-weak (sn _w ) locus was observed in F₃–F₁₀ with a subsequent decrease and stabilization of the mutation rate. The sn ^w mutation rate was within the range of spontaneous variation in conditions of P-M hybrid dysgenesis and irradiation of males of the Harwich laboratory strain with active P elements at 1.61 mGy/h. The instability of the sn ^w locus was significantly higher at lower dose rates (0.23 and 0.31 mGy/h), suggesting a nonlinear dose-effect relationship.     

Allozyme diversity in the federally threatened golden paintbrush, <Emphasis Type="Italic">Castilleja levisecta</Emphasis> (Scrophulariaceae)

Castilleja levisecta (Scrophulariaceae), the golden paintbrush, is an insect-pollinated herbaceaous perennial found in the Pacific Northwest. Currently restricted to two island populations off British Columbia and nine populations (eight on islands) in Washington, C. levisecta is a rare species threatened with extinction. Allozymes were used to describe genetic diversity and structure in these eleven populations. Despite its threatened status and small geographic range, exceptionally high levels of genetic diversity are maintained within C. levisecta. All sixteen of the loci resolved were polymorphic within the species (P_s=100%), while the mean percentage of loci polymorphic within populations (P_p) was 65.7%. The mean number of alleles per polymorphic locus (AP_s) was 2.94 within the species and averaged 2.38 within populations (AP_p). Genetic diversity (H_es) was 0.285 for the species, whereas mean population genetic diversity (H_ep) was 0.213. Smaller populations had, on average, fewer observed alleles and less genetic diversity. A significant negative correlation (r = –0.72) was found between genetic identity and geographic distance, indicating reduced gene flow between distant populations. The most geographically isolated population was one of the larger populations, one of the most genetically diverse and the most genetically divergent. A wide range of pairwise population genetic identities (I = 0.771 – 0.992) was found, indicating considerable genetic divergence between some populations. Overall, 19% of the total genetic diversity was distributed among populations. Results of this survey indicate that genetic augmentation of existing populations is unnecessary. The high allelic diversity found for the species and within its populations holds promise for conservation and restoration efforts to save this rare and threatened plant species.     

Ontogenetic features of <Emphasis Type="Italic">Dolichopithecus</Emphasis> (Primates,Colobidae) from the Pliocene of Pridnestrovie

In the permanent dentition of the extinct genus Dolichopithecus, M₁, I₁, and I₂ were the first to erupt, followed by M₂, canine, P₄, and P₃. M₃ was the last permanent tooth to erupt. At the stage of eruption of P₄ and P₃, M₃ was incompletely mineralized. The difference from the extant Cercopithecoidea is the loss of all deciduous teeth after eruption of incisors and M1 and the similarity is observed in the succession of eruption of permanent teeth. In Dolichopithecus, the lower jaw body retained constant in thickness after eruption of M₂. The lower jaw increased in length and depth, as the horizontal ramus grew with the formation and eruption of M₃.     

Dental characters of the Quaternary tapirs in China, their significance in classification and phylogenetic assessment

Most of the Quaternary tapir fossils from China are isolated teeth. The purpose of this paper is to identify them and to extract systematic and evolutionary information from them. Based on morphology and W/L ratio, isolated teeth can be identified successfully. On the whole, the identification of P¹, M³ and P₂ is believed to be reliable, while it is difficult to distinguish P₃ from P₄, M₁ from M₂ etc. Concerning the variations of the teeth, P¹ is the most variable one in dimension. In the Quaternary tapirs in China, some dental characters can be used as reliable indicators to evaluate their evolutionary levels. The degree of the atrophy of the upper canine relative to the caniniform I³ is reflected in the C/I³ diameter ratio, which is decreasing during evolution. P¹ changes considerably in outline and strength of the hypocone. Some forms are without hypocone, such as Tapirus sanyuanensis, some have a very faint hypocone, such as Tapirus indicus; although most of them show a developed hypocone. For other cheek teeth, the W/L ratio is decreasing through geologic time. Two lineages can be tentatively proposed: one is the Tapirus peii-Tapirus sinensis-Megatapirus augustus progression; the other is the T. sanyuanensis-T. indicus lineage. T. sanyuanensis and T. peii stand on the base, and it is very probable that the latter is more primitive.     

Genetic diversity of four esterase loci in natural populations of Hordeum spontaneum C. Koch from Jordan

Summary The diversity of four esterase loci was studied electrophoretically in 690 individual spikes representing 12 populations of wild barley (Hordeum spontaneum C. Koch.) collected from central, peripheral and marginal regions of its distribution in Jordan. A minimum of 6, 10, 5 and 5 alleles were observed at the Est-1, Est-2, Est-4 and Est-5 loci, respectively. Est-2 and Est-4 were the most diverse loci (H_c=0.53±0.05 and 0.46±0.07, respectively). Est-5 was intermediate (H_c=0.33+0.07) and Est-1 was the lowest (H_c=0.22±0.04). Polymorphism was highest in the central populations (H_e=0.52±0.04), followed by the peripheral (H_e=0.40±0.05) and the marginal (H_e=0.22±0.05) populations. Average allelic diversity between (G_st=0.49) and within (H_s=0.51) populations reflects a high allelic differentiation among these populations. Log-linear analyses revealed that four two-locus terms and two three-locus terms were significantly associated (P<0.05). Geographical distances between populations were not significantly correlated with Nei's genetic similarity index (r=0.16; P<0.19). It is postulated that diversifying selection is a major factor in the population genetic differentiation of these esterase loci.