Torus palatinus in Icelandic schoolchildren

Three populations in South- and North-Thingeyjarsyslas, Northeast Iceland, were surveyed for the presence of torus palatinus. A total of 987 schoolchildren (489 male and 487 female) were examined. A statistically significant difference was noted between the prevalence in South-Thingeyjarsysla (33.3%) and North-Thingeyjarsysla (14.6%). Prevalence and size were affected by age and population but not by sex. An association between torus palatinus and torus mandibularis was not found. Secular changes in the occurrence of torus palatinus in Icelanders emphasize the importance of environmental etiological factors and diminish the value of torus palatinus as a racial trait.     

Some observations on the dentition of an isolated group in northeast Poland.

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.     

Torus mandibularis in an Alaskan Eskimo population

One of the lowest reported incidences of torus mandibularis (10.7%) in an Eskimo population was observed in the Wainwright, Alaska group studied during 1968. In this population the tori generally did not appear until after the age of 40 years in contrast to other Mongoloid populations previously reported. There was no size difference between males and females, but the males exhibited a much higher incidence of this exostosis. The tori did not significantly increase in size with increasing age after their appearance late in life.     

Torus mandibularis in 45,X females (Turner syndrome)

Ninety-three Finnish females with a 45,X chromosome constitution, 78 first-degree female, and 37 first-degree male relatives were examined to determine the frequency and expression of torus mandibularis. The results indicate that among adults the frequency of the trait was significantly lower and the expression weaker in the 45,X females than in male control relatives. A similar trend was observed in comparison to normal females. In juveniles the trend was reversed. Our findings suggest that the sex chromosomes may have an influence on the occurrence, expression, and timing of development of the mandibular torus. Sexual dimorphism in the manifestation of torus mandibularis may result particularly from the effect of the Y chromosome on growth. © 1996 Wiley-Liss, Inc.     

The frequency and anatomical features of torus mandibularis in a Black South African population.

Torus mandibularis is a rounded bony protuberance on the lingual surface of the mandible and usually found above the myolohyoid line, medial to the molar roots. This report describes the frequency and morphology of torus and also proffers the likely cause among black South Africans. A total of 284 modern skeletal specimens were obtained from the Raymond Dart Collection of Human Skeletons at the School of Anatomical Sciences, University of the Witwatersrand. The mandibles were classified into dentate and edentulous, while those with torus, especially in dentate mandibles, were reviewed for side location, type and shape. No measurements were made, consistent with the view that these characteristics are non-metrical and should be assessed by means of a standard observatory procedure. Out of 246 dentate mandibles, 60 (24.4%) were found to have torus and only 1 (4.3%) out of the 23 male edentulous mandibles; the difference is statistically significant (P=2.8%). The torus distribution among males and females was 48 (80%) and 12 (20%), respectively, and again statistically significant (P< 0.05). Prevalence of torus was highest in the 40–60 years age group. The morphology of the torus showed that 37 (61.7%) were bilateral in location, 42 (70%) were of the solitary type and 31 (51.7%) were round in shape. The formation of torus follows the threshold model which holds that this is primarily a genetic trait, but with environmental factors such as mechanical stress necessary for its development.     

Analysis of contingency table data on torus mandibularis using a log linear model

The hypothesized sexual difference in the incidence of torus mandibularis in Eskimoid groups, as well as age and group differences, was studied in two Northwest Territories Eskimo groups and in an Aleut group (examined by Moorrees). The data were analyzed using statistical methods new to the field of anthropology. The method analyzes data sampled from a multinomial distribution. A hierarchy of log linear models are fitted to the cell counts of a contingency table. An iterative proportional fitting procedure is used to obtain expected cell counts under each log linear model. The “goodness of fit” of each model is tested by the log likelihood ratio. This statistic can be partitioned into additive components such that differences between models can be tested. In this way a “best” model, from the hierarchy of models, is chosen. Among these three groups of Eskimos, the incidence of torus mandibularis was not affected by sex but was affected by age and was different between the three groups.     

Palatal and mandibular tori in a Romanian removable denture-wearing population

doi:10.1111/j.1741‐2358.2009.00318.x
Palatal and mandibular tori in a Romanian removable denture‐wearing population Objective: To establish the prevalence of palatal tori (TP) and mandibular tori (TM) in a Romanian denture‐wearing population in order to see how or if tori influenced the denture design or the treatment planning. Background data: There are no available data regarding tori in an elderly Romanian population and its implication for treatment planning. It could be considered a local factor influencing the quality of prosthetic treatment. Material and method: Tori prevalence was investigated in 251 patients, with an average age of 62 years. A statistical analysis was made, using odds ratio (OR) for the distribution related to gender and the Chi‐squared test for the differences in prevalence related to age groups. Treatment planning difficulties because of presence of tori were recorded. Results: Frequency of TP was significantly higher in both genders (OR = 2.0661 and p = 0.0446) and non‐significant frequency for distribution between genders for TM (OR = 0.9421 and p = 0.8273). The differences in age groups showed both tori types have a variable prevalence related to age. The most frequent location for TP was found in the posterior one‐third and two‐thirds of the palate and for TM in the canine and first premolar area presenting with different sizes. Conclusions: Tori prevalence in our study group is high and is significantly related to age (p < 0.05) having a peak at over 60 years. The preferential site of TP in the posterior palatal area and this location has an impact on decision making in treatment planning for the upper denture.     

Torus mandibularis in two Northwest Territories Villages

A study of 433 Canadian Eskimos from the villages of Igloolik and Hall Beach, Northwest Territories, revealed an incidence of torus mandibularis of 39.7% in Igloolik and 37.3% in Hall Beach. No statistically significant differences in size or incidence were noted in a comparison of males and females of the two communities. Further, there were no significant differences in the expression and incidence of the torus between the two villages. The incidences noted in these two communities were comparable with the incidences reported for other Eskimos subsisting upon an essentially aboriginal diet but were higher than those previously published for the Wainwright, Alaska, Eskimos who appear to be more acculturated. Studies within the villages indicate that those individuals ingesting a predominately European diet display reduced incidence of the torus when compared with those individuals on a more aboriginal diet.     

Acetylation of pea isolate in a torus microreactor

Acetylation, which acts on the amino groups of proteins, allows to increase the solubility and the emulsifying properties of pea isolate. Acetylation by acetic anhydride was carried out in a torus microreactor in semibatch and continuous conditions. The mixing characteristics, obtained by a residence time distribution (RTD) method, are the same in batch and continuous processes. The maximum acetylation degree reached by the torus reactor is higher than with the stirred reactor. Torus reactors are more efficient than stirred ones as shown by a conversion efficiency, defined by the quantity of modified lysine groups by consumed acetic anhydride. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 409-414, 1997.     

The role of heterogeneity in the persistence and prevalence of Sin Nombre virus in deer mice

Many diseases persist at a relatively low prevalence, seemingly close to extinction. For a chronic disease in a homogeneous population, reducing the transmission rate by a fraction proportional to the prevalence would be sufficient to eradicate the disease. This study examines how higher prevalence of the Sin Nombre virus in male deer mice (Peromyscus maniculatus) might contribute to disease persistence. Analyzing data from over 2,000 individual mice captured in 19 sites over 4 years, we found prevalences of 18.5% in males and 8.8% in females. By examining recaptures, we determined that males are more likely to contract the infection because of higher susceptibility or higher encounter rates. Comparing across 86 sampling periods, we found a higher proportion of males when population densities were low. A capture-recapture analysis indicates that males live longer than females. A mathematical model based on the measured parameters and population size trajectories suggests that the combined heterogeneity in encounters, susceptibility, and mortality may buffer the disease from extinction by concentrating disease in the subgroup most likely to transmit the disease. This buffering effect is not significantly stronger in a fluctuating population, indicating that these forms of heterogeneity might not be the key for disease persistence through host population bottlenecks.     

The Incidence of Double Hypoglossal Canal in Japanese: Evaluation with Multislice Computed Tomography

ResultsDouble hypoglossal canal was identified in 16.9% of the patients, and was bilateral in 2.2%. Double hypoglossal canal was significantly more frequent on the left side than right (P = 0.004, odds ratio = 1.79) and in males than females (P = 0.011, odds ratio = 1.67). A larger left or right-sided canal was found in 31.6% and 12.2% of the patients, respectively, following the same side preference as that of double hypoglossal canal. Almost perfect agreement was achieved between the two readers (k = 0.975).ConclusionsIn this Japanese population, the prevalence of a double hypoglossal canal was 16.9%, of which 2.2% were bilateral. Double hypoglossal canal was more frequent in males than females, and on the left side than right.     

Calcaneous ultrasonographic assessment of bone mineral density in the Roma minority population of Croatia--preliminary report

A multidisciplinary anthropological and epidemiological pilot field study of the Bayash population living in 6 villages of the eastern Croatian region of Baranya has been performed in 2005/06. The Bayash (or Boyash) belong to the Roma minority population speaking a distinct archaic dialect of the Romanian language. Since the bone mineral density values in the Roma have not been explored so far and the prevalence of osteoporosis is unknown for this ethnic minority group a screening by means of the Sahara Hologic clinical bone sonometer has been performed on 232 voluntary participants (73 males and 159 females). The prevalence of osteoporosis (T-score <-2.5) in the Bayash aged 50 and older is found to be 9.1% in males and 34.4% in females, which is substantially higher than in the general population of Croatia. The prevalence of T-values ranging from -1 to -2.5 indicating osteopenia is found to be 63.6% in males and 45.3% in females, while T-values within the normal range are found only in 27.3% males and 20.3% females. In addition to the low bone mass in older subjects, the mean estimated bone mineral density in all age groups of Bayash men and women was lower in comparison to the manufacturer's reference ranges for European population of the same age. Since body size effects could not be declined, the reference values that would be appropriate for the Roma population should be further explored. The high estimated prevalence of developed osteoporosis calls for attention and the survey should also be extended to exploring the association of low bone mineral density with particular life style and reproductive factors present in this semi-sedentary Roma population.     

Prevalence of meningeal worm (Parelaphostrongylus tenuis) in white-tailed deer from New Hampshire

Parelaphostrongylus tenuis was found in 79 (62.2%) of 127 white-tailed deer heads (Odocoileus virginianus) collected in New Hampshire. Prevalence of infection was higher in fawns and male deer, but older female deer (5.0 + years) had a higher intensity of infection (3.1) than any other age or sex class. Male deer in forest cover type 2 (northern hardwoods-hemlock-white pine) had a significantly greater prevalence of infection than the females in the same habitat (P less than .05). Adult females had a higher prevalence of infection (67.0%) than female fawns (20%) in forest cover type 1 (spruce-fir-northern hardwoods). In the craniums examined, P. tenuis was found most frequently in the tentorium cerebelli (23.6%) while the falx cerebri, the most prevalent site of infection in fawns, was a significantly less frequent site of infection in older deer (P less than .02). Male deer of age class 3.5 years had a significantly higher rate of infection in the dura mater-olfactory lobe than any other age or sex group (P less than .02). The cavernous sinus was the most frequent site of parasitism in male fawns (25.0%) and was the second most common location in all deer (13.4%).     

Mitochondrial haplogroup N9b is protective against myocardial infarction in Japanese males

Superoxide, which mitochondria mainly produce in vascular endothelial cells, plays an important role in the pathogenesis of atherosclerosis and coronary artery disease. Accordingly, mitochondrial functional differences are thought to be one of the most important factors for the risk of myocardial infarction among various individuals. In the present study, we surveyed mitochondrial haplogroups associated with myocardial infarction in Japanese subjects. The study population comprised 2,137 unrelated Japanese individuals, including 1,181 subjects with a first myocardial infarction (920 males, 261 females) and the control subjects (522 males, 434 females). Twenty-eight mitochondrial single nucleotide polymorphisms of 12 major mitochondrial haplogroups (A, B, D4, D5, F, G1, G2, M7a, M7b, M7c, N9a, and N9b) were determined by use of 28-plex PCR and fluorescent beads combined with sequence-specific oligonucleotide probes. After adjustment for age, sex, body mass index, and prevalence of smoking, hypertension, hypercholesterolemia, and type 2 diabetes, a significantly (P = 0.0019) lower prevalence of haplogroup N9b was detected in subjects with myocardial infarction than in the controls. Especially, the prevalence of this haplogroup was significantly lower (P = 0.0007) in the male subjects with the disease than in the male controls. In contrast, there were trends towards higher prevalence of the disease in haplogroup G1 for males (P < 0.05). No significant haplogroup-related associations were detected for females. Our data suggest that haplogroup N9b confers resistance against myocardial infarction in Japanese males. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Mandibular torus morphology

The morphology of the mandibular torus was examined, and comparisons were made between a Medieval Norse skeletal population from Greenland and a 14th to 17th century Greenland Eskimo skeletal series. Three parameters were analyzed: degree of development (on a 4-point scale), position and length, and surface morphology according to the number of knobs, or lobuli. It was found that the Eskimos have a high frequency of weakly developed tori and no cases of the extreme development, while over 20% of the Norsemen had tori in the “extreme” category. The Norse torus was generally found to be longer than that of the Eskimos, and both groups exhibited a slight asymmetry between the sides, the torus on the left side tending to be longer and more forward in position than the right. A great difference was found in surface morphology. The Norse torus is in general very irregular, while the Eskimo torus is rather smooth. These differences are believed to be genetically determined.     

Evaluation of host preferences by helminths and ectoparasites among black-tailed jackrabbits in northern California

Fifty-four black-tailed jackrabbits (Lepus californicus) (five juvenile males, 22 adult males, five juvenile females, and 22 adult females) from Humboldt County, California (USA) were evaluated for sex and age-specific differences in parasite prevalences and intensities, 26 February through 30 October 1996. Nematodes found included Biogastranema leporis in 42 hares (78% prevalence), Rauschia triangularis in 26 hares (48%), Trichostrongylus calcaratus in 14 hares (26%), and Trichuris sylvilagi in two hares (4%). Cestodes found included Taenia sp. cysticerci in five hares (9%) and Taenia sp. coenurus found in one hare (2%). Ectoparasites found included the ticks Dermacentor variabilis on 10 hares (19%) and Ixodes spinipalpis (= Ixodes neotomae) on nine hares (17%), as well as the anoplurid louse Haemodipsus setoni on 12 hares (22%). No significant differences in the parasite prevalences or intensities were found between male and female jackrabbits; this was for all males and females collectively, juvenile males and females only, as well as adult males and females only. Combining male and female hosts, adult jackrabbits had a significantly higher prevalence of B. leporis and R. triangularis compared to juveniles. This is the first known report of Trichostrongylus calcaratus, Rauschia triangularis, Trichuris sylvilagi, and Dermacentor variabilis among black-tailed jackrabbits and the first known report of T. calcaratus and T. sylvilagi in the western USA. This is the first published report of I. spinipalpis, the vector for Lyme disease in California, on black-tailed jackrabbits.     

Prevalence of primary adult lactose malabsorption in Hungary

Lactose absorption capacity was estimated in 820 apparently healthy, well nourished, Hungarian adults and adolescents (560 females, 260 males, aged 16-54 years) using a field version of the lactose tolerance test with breath hydrogen determination. The test identified 497 lactose absorbers with low, and 323 lactose malabsorbers with high hydrogen excretion 120-150 min after an oral load of 50 g lactose. The prevalence of lactose malabsorption in the general Hungarian sample (n = 535) was 37%. In subgroups from the western and eastern Hungarian plains, frequency of lactose malabsorption reached almost 30%. It tended to be higher in Upper Hungary (ca. 40%) and in subjects stemming from former Hungarian areas in the Carpathian bend. Lactose malabsorption in a Hungarian ethnic subgroup, the Matyo (n = 172), did not differ significantly from that in the general population. Among Romai ("Gypsies", n = 113), the prevalence of lactose malabsorption was significantly higher (56%). Awareness of milk intolerance was significantly more frequent, and severe symptoms of lactose intolerance during the test occurred almost exclusively in lactose malabsorbers.     

Prevalence of hepatitis B markers in Indochinese refugees.

The prevalence of hepatitis B surface antigen (HBsAg) in 14 347 Indochinese refugees was 11.6%; the rate was significantly higher (P less than 0.01) in males (14.0%) than in females (8.8%). Most of the HBsAg-positive refugees were in the age group 20 to 29 years. Antibody to HBsAg was detected in 50.9% of the males and 46.6% of the females, a significant difference (P less than 0.01). Antibody to core antigen alone was found in 2.4% of the males and 2.2% of the females. The cumulative prevalence of one or more hepatitis B markers was significantly higher (P less than 0.001) in the males (67.3%) than in the females (57.5%). The hepatitis B e antigen and its antibody were detected in 54.8% and 39.2% respectively of 1050 HBsAg-positive blood samples. The adw, adr and ayw determinants of HBsAg were found in 23%, 35% and 42% respectively of 74 samples.     

Hypodontia: Prevalence amongst Jewish populations of different origin

The teeth of 10,371 male and 11,013 female Israel Jews were examined. Prevalence of all hypodontia was 4.60% with no significant difference between the sexes; 2.11% lacked upper lateral incisors, the females having a significantly higher prevalence than males. Second premolars were missing in 1.87% of the population, with no significant differences between the sexes. Missing lower incisors was diagnosed in 0.68% of the children, with a higher prevalence in males. Prevalence of missing lower incisors was similar in the Ashkenazi and in the non-Ashkenazi. The teeth most frequently missing in descending order were the upper lateral incisors and the lower second premolars.