Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  dental anomaly
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Dental anomalies in the gray fox Urocyon cinereoargenteus and the fox Vulpes vulpes

100%
Gisburne T. J., Feldhamer G. A.
Acta Theriologica
|
2005
|
tom 50
|
nr 4
515-520
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.
2

Extra teeth and dental anomalies in the crested porcupine Hystrix cristata, from Sicily

100%
Angelici F. M., Luiselli L.
Acta Theriologica
|
1999
|
tom 44
|
nr 2
We examined 181 skulls of crested porcupine Hystrix cristata Linnaeus, 1758 from Sicily, mainland Italy, and from several African countries. Two skulls, both from Sicily, had anomalous dentition. One skull exhibited a case of supernumerary dentition, whereas the other one showed a dental malformation with numerary teeth reduction. The type of anomaly was determined in each skull examined and some hypotheses for explaining these anomalies were presented.
3

Loss of the third upper premolar in Suncus murinus and its relation to jaw size

100%
Natori M., Shigehara N.
Acta Theriologica
|
1997
|
tom 42
|
nr 1
Musk shrew Suncus murinus (Linnaeus, 1766) has a very reduced P3, and it is often missing. Hanamura (1985), based on a sample from Okinawa Island, proposed that the high incidence in P3 loss was a distinguishing characteristic of musk shrew. However, while the Okinawa population lacked P3 in 26 of 95 individuals (27.4%), specimens from Taiwan showed no P3 loss. Thus, the high incidence of P3 loss is not one of distinguishing characteristic of musk shrews. In the Okinawa sample, P4-M3 length vs palatal length in the group with P3 on both sides was significantly greater than that without P3. The relationship between the P4-M3 and palatal lengths showed negative allometry (Okinawa population with P3: y = 0.18 + 0.67a:; Okinawa population without P3: y = 0.21 + 0.67x; Taiwan population: y = 0.15 + 0.68x). Taiwan population had a greater P4-M3 length relative to palatal length than did the Okinawa population because palatal length was greater in the former. These findings suggest that, as in the case of human third molars, a reduction in upper jaw size is responsible for the loss of the third molar in the Okinawa musk shrews.
4

Population analysis of dental anomalies of otters Lutra lutra from Eastern Germany

100%
Hauer S.
Acta Theriologica
|
2002
|
tom 47
|
nr 3
A sample of 1037 skulls of otters Lutra lutra (Linnaeus, 1758) from eastern Germany was analysed for inherent dental abnormalities. Deviations from the normal dental pattern were found in 107 individuals. A total of 150 cases were classified in 5 categories of abnormality. In considering variations from the normal number of teeth, supernumerary (polydonty, 1.7%) was more frequent than missing teeth (oligodonty, 0.9%). In most cases, numerical variations were not connected with phylogenetic background. The most frequent variations were displacement of teeth in the tooth row (6.0%) and deviations of the normal shape of teeth (3.3%). Variations of the local position of teeth occurred in 2.6% of cases. None of these deviations showed significant sex-dependent differences. Furthermore, no regional differences in the frequencies of these anomalies were noticed. Another 459 otters (822 cases) had accessory roots at P2, P3, or P4. These characters were considered as non-metrical traits and used to study epigenetic regional differentiation. The Mean Measure of Divergence segregated the Baltic coast from almost all other regions. Preliminary results of analysis of Fluctuating Asymmetry are presented, using these traits to demonstrate the utility of dental deviations for estimating influences on developmental stability. Generally, it can be stated that the dentition of otters is very stable.
5

Dental anomalies in wild and domestic Sus scrofa in Illinois

100%
Feldhamer G. A., McCann B. E.
Acta Theriologica
|
2004
|
tom 49
|
nr 1
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.
6

Craniometrical characteristics and dental anomalies in wolves Canis lupus from Latvia

84%
Andersone Z., Ozolins J.
Acta Theriologica
|
2000
|
tom 45
|
nr 4
A total of 187 skulls (115 adult males and 72 adult females) of the wolf Canis lupus Linnaeus, 1758 hunted in Latvia between 1975-1999 were measured, using 19 cranio­metrical parameters. General cranial characteristics were similar to those described from the wolf populations of Belarus and Poland (the difference was not statistically significant). Sexual dimorphism in skull size was determined. Most of the skull para­meters from north and east Latvia appeared to be slightly larger than those from the Kurland Peninsula, being isolated by large cities, rivers and deforested lands. Also, anomalies in tooth formula were described. Deviations from the normal tooth pattern were found in 9.5% skulls. Congenital oligodonty and polydonty was found in 7.9% skulls. Polydonty was observed in 71.4% cases of tooth anomalies. Tooth anomalies were more common in males than in females.
7

Dental anomalies and dental variations in the red fox Vulpes vulpes in the Czech Republic

84%
Nentvichova M., Andera M.
Acta Theriologica
|
2008
|
tom 53
|
nr 3
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.
8

A supernumerary tooth and an odontoma attributable to Mammuthus primigenius [Blumenbach, 1799] [Mammalia, Proboscidea] from The Netherlands, and various related finds

84%
Van E. H.
Acta Zoologica Cracoviensia
|
2004
|
tom 47
|
nr 1-2
Two dental anomalies referable to Mammuthus primigenius (BLUMENBACH, 1799) are described. The first is a unilateral supernumerary tooth in a mandible with M3 in advanced wear (part I). A mandible with two supernumerary teeth from Otterstadt (Germany) was published earlier, but interpreted as an anomalous replacement of M2 by M3 (ADAM 1994). The discussion therefore focuses on the implications of this alternative theory and the arguments against it. On the basis of specimens in mandibles, some isolated finds of mammoth teeth from various locations in western Europe are tentatively presented as supernumerary. The second anomaly is a compound odontoma that developed around a normal M3. Previously published elephantid odontomas are discussed and a preliminary survey of their macroscopic characteristics as opposed to those of supernumerary teeth is presented. Some terminological problems arising from the imperfect morphological analogy between anomalies in human and elephantid dentitions are discussed.
9

Dental anomalies in the Japanese mole Mogera wogura from northeast China and the Primorsky region of Russia

67%
Asahara M., Kryukov A., Motokawa M.
Acta Theriologica
|
2012
|
tom 57
|
nr 1
Dental anomalies in the Japanese mole, Mogera wogura Temminck, 1842, from northeast China and the Primorsky region of Russia were examined based on 241 specimens. The most frequent dental anomaly was oligodonty, i.e., missing P2 (18 cases) or P3 (one case). Supernumerary teeth were observed in three cases, two of which were characterized by abnormal shapes. Morphological abnormalities in teeth (six cases) and an asymmetrically curved rostrum (one case) were also observed. Dental anomalies were found at higher frequencies in populations near the northern range limit of the species. This was not caused by size effects. We suggest that the high incidence of dental anomalies was the result of genetic drift, which increases in marginal populations. Considering the nature of subterranean mammals, our results suggest that the high frequency of dental anomalies in a marginal population could have initiated the evolution of dental formulae if parapatric or peripatric speciation occurs in such populations.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.