PubMed Health⌕ Search

Biomedical subjects

S Eggen

Publications and source records attributed to S Eggen.

At least 19 recordsLinked to original sources
PubMed1994

Variation in torus palatinus prevalence in Norway.

The variation in torus palatinus (TP) prevalence was investigated among a total of 2010 dental patients over 10 yr of age native to two different regions in Norway, the Lofoten Islands in northern Norway and the Gudbrandsdalen valley, an inland area in the southeastern part of the country. The two groups were presumed to belong to the same Caucasian stock, but were extremes with regard to the fish-to-meat ratio of the diet, which was 3:1 in Lofoten and 1:3 in Gudbrandsdalen, respectively representing a soft type of diet, and a tough type requiring greater muscular forces during mastication. The study revealed: 1) the prevalence of TP was higher among women than men; 2) TP seemed likely to arise from a multifactorial liability, with part of the genetic factors residing on the X chromosome; 3) the prevalence of TP appeared to be higher among natives of Lofoten, who consume the softer food, than among natives of Gudbrandsdalen, the higher prevalence being hypothesized to have some connection with nutrient substances present in saltwater fish, possibly omega 3 polyunsaturated fatty acids and vitamin D; and 4) TP seemed to be a dynamic phenomenon capable of growth and subject to resorption remodeling.

Adolescent↗
PubMed1994

Concurrence of torus mandibularis and torus palatinus.

Analysis of the concurrence of torus mandibularis and torus palatinus among a total of 2010 dental patients, by the test of independence, revealed that the concurrence was statistically significant among women, but not among men. A tentative hypothesis was proposed to explain the sexual dimorphism of the variable, combined occurrence of the two features.

Adolescent↗
PubMed1992

Correlated characteristics of the jaws: association between torus mandibularis and marginal alveolar bone height.

The factor marginal alveolar bone height and torus mandibularis (TM) were studied in 2 groups of dentate patients more than 20 years of age, altogether 571 individuals. Subgroups possessing TM had the higher prevalence of unimpaired bone height as compared with those without the trait (P less than 0.001). Different environmental factors considered, such as food habits, exposure to infection, oral hygiene habits, bruxism, access to professional dental care, and habits as to seeking dental treatment, did not seem to account for or to have any influence on the observed phenotypic correlation between TM and more favorable bone height. It was therefore suggested that TM and marginal bone seem to be influenced by common pleiotropic genes. It is hypothesized that future disclosure of the loci that regulate the capacity to develop TM at the same time may throw some light on the genetic contribution and mechanisms that tend to make the marginal alveolar bone more resistant to destructive agents.

Adult↗
PubMed1991

Variation in torus mandibularis prevalence in Norway. A statistical analysis using logistic regression.

The prevalence of torus mandibularis was assessed in two groups of dental patients, altogether 2010 individuals over 10 yr of age: 1181 individuals native to the Lofoten Islands in North Norway, situated at 68 degrees latitude; and 829 patients indigenous to Gudbrandsdal, an inland district in the southeastern part of the country at 61 degrees latitude. Both groups were supposed to be of the same Caucasian stock and, therefore, to have similar genetic predisposition to torus on the average. The following observations were found: 1) the prevalence of torus mandibularis was much greater in Gudbrandsdal than in Lofoten (P much less than 0.001); 2) the prevalence decreased among persons above 50 yr of age as compared with those of the age classes 10-49 yr (P less than 0.01); and 3) it was smaller among women than men (P less than 0.05), mainly due to such a decrease in Lofoten. In a recent investigation of people living in Gudbrandsdal the fraction of the variation of torus that was attributable to genetic differences was estimated as about 30%, whereas approximately 70% of the causes seemed to be ascribable to environmental influences in terms of occlusal stress. It is suggested that dietary habits and number of existing teeth seemed to be environmental variables with an influence on the observed variation of torus prevalence between geographical regions, age classes, and sexes. The question about a possible sexual difference as to the genetic component of liability to torus mandibularis was outside the scope of the present study.

Adolescent↗
PubMed1989

Torus mandibularis: an estimation of the degree of genetic determination.

Torus mandibularis has frustrated several attempts to make family patterns of variation fit modifications of Mendelian models. It is suggested that the quasi-continuous model of inheritance provides a rational explanation for the diverging opinions. The model implies an underlying continuous and normally distributed variable, 'liability', with a threshold value beyond which individuals will be affected. Both genetic and environmental factors determine liability, making the system multifactorial. The incidence of variable degrees of torus was examined in two groups of patients with different stresses on the jaws: one group with bruxism and one comparison group. The transformation of incidences to group means and variances of liability was demonstrated. Muscular forces during bruxism were shown to influence liability. The relative importance of environmental and genetic components of variance could, however, not be estimated directly from the entire groups, since both were mixed with regard to the genetic predisposition. To achieve materials with uniform genotypes, all individuals without torus were omitted. The estimate of the genotypic variance (VG) was obtained by subtracting the variance of the bruxism sub-group--the environmental component associated with bruxism (VEB)--from the total phenotypic variance of the comparison sub-group (VP). The estimate of the genetic determination of torus (VG/VP) turned out to be about 30%, whereas approximately 70% of the causes seemed to be attributable to environmental influence in terms of occlusal stress. Gene effects on the morphologic level are usually pleiotropic, and it is suggested that the correlation of torus mandibularis with other clinical variables might make an interesting subject for further investigation.

Adult↗
PubMed1989

[Marginal bone loss among adults: have the conditions changed since the 1950's?].

It has been suggested that periodontal diseases have declined during the last 2-3 decades in many populations. However, the present observations on marginal bone loss among 326 Norwegian dental patients aged 20-70 years, examined 35 years ago, were similar to comparable data published more recently. Consequently, they did not indicate any tendency towards change over time. Traditionally, the Periodontal Index (PI) has been the method of choice for assessing the prevalence and severity of periodontal disease in epidemiological studies. It was assumed that this may have lead to an overestimation of the periodontal destruction, and that the postulated improvement of the condition partly may be ascribed to methods of analysis rather than reality. The observations seemed to indicate that susceptibility to destructive periodontal disease may not be as universal as was previously thought; the majority of the patients could probably retain a considerable proportion of the supporting bone up in high age by routine prophylaxis and improved home care. On the other hand, bone destruction was a serious problem among a minority of "risk" individuals after the age of 40. This subgroup was estimated to make up about 10% of the population. Similar estimates also appeared in published studies on statistical samples from other populations. The individual resistance to periodontal destruction is probably very important for the marginal bone level. The constituent elements of the resistance concept do, however, need further elucidation.

Adult↗
PubMed1986

Relationship between torus mandibularis and number of present teeth.

Comparison of incidence of torus mandibularis and average number of present teeth among 2010 consecutive dental patients over 10 yr of age revealed that these variables seemed to be positively related: patients with torus mandibularis had on the average more teeth present than those without torus (P less than 0.0000001). The difference was statistically significant in all age classes except 50 years and over. In the adolescent age class, 10-19-yr, patients with torus mandibularis had on the average fewer unerupted canines than those without torus indicating that the hyperostosis seemed to be associated with more adequately developed jaws. The decreasing incidence of torus mandibularis with age approximately paralleled the decreasing number of present teeth, indicating that number of functioning teeth seems to be a factor of importance for the maintenance of the trait.

Adolescent↗
PubMed1983

Evaluation of the reproducibility of two bitewing techniques by means of a microdensitometric recording method.

A new, simple, metal bitewing holder with a radiation dose-reducing collimator using principles suggested by Eggen is presented and recommended. The reproducibility of the bitewing holder technique was compared with that of the conventional bitewing loop technique. The material consisted of twenty seven sets (fifty four pairs) of radiographs. A microdensitometric method was developed and used to assess the reproducibility of the radiographs, and 108 pairs of microdensitometric tracings were produced to evaluate the two techniques. The results showed that the metal bitewing holder was significantly superior to the bitewing loop for obtaining radiographs with high reproducibility. The suitability of the microdensitometric method is discussed.

Densitometry↗
PubMed1982

Measurements of alveolar bone height at tooth and implant abutments on intraoral radiographs. A comparison of reproducibility of Eggen technique utilized with and without a bite impression.

A short review of various radiographic methods for quantitation of marginal bone changes is given. With the method suggested by Eggen (1973) alveolar bone heights on intraoral paralleling radiographs of tooth and implant abutments could be determined directly in "true' values. A calibrated measuring film (increments adjusted in accordance with the approximately constant magnification) was utilized with a magnifying (x 2) viewer. The reproducibility of this direct method was tested, with and without a bite impression, and found to be high. The use of an impression did not seem to have any significant influence on the reproducibility of the method when measuring bone heights at teeth. However, regarding bone height measurements at implants, the impression seemed to bring about a small but significant improvement. The main source of error seemed to be the recognition of the reference points in the alveolar bone. The discussion of available quantitation principles indicated that radiographic bone height should be evaluated in absolute values in clinical studies of comparative nature. The present method seems to be suitable for comparative, clinical examinations of alveolar bone height at teeth and implants.

Adult↗
PubMed1982

Comparative study of two evaluation methods on radiographic bone loss at the mandibular canines and incisors.

The approximal bone loss of the mandibular canines and incisors was scored with two different units of measurement on 30 sets of standardized paralleling radiographs: 1) with absolute values ("true" millimeter) unrelated to casual variables and 2) with relative values (i.e. percentage of the root length). Absolute bone loss scores revealed that the space between the canines and the lateral incisors of the present material seemed to be more susceptible to bone loss than the spaces between the incisors, with a tendency towards the mesial bone loss of the canines being still greater than the distal bone loss of the laterals. There was a high degree of correspondence between absolute bone loss scores at different teeth and corresponding gingival pocket depths of a previous analysis by the present authors. Relative bone loss scores led to divergent and partly direct-opposite results compared with the absolute scores. The correspondence between percentage bone loss scores and gingival pocket depths at corresponding tooth surfaces was poor. When investigating the susceptibility of different teeth to periodontal breakdown it seems as if bone loss should be expressed in absolute values in the same way as are gingival pocket depths and loss of attachment. If a common standard is being used the results of different investigations may be compared. However, when studying the inception and advancement of the disease at the same tooth over a period of time, or when evaluating the remaining bone support the percentage bone loss method may be of clinical importance.

Adolescent↗
PubMed1979

Determination of tooth length with a standardized paralleling technique and calibrated radiographic measuring film.

A simple radiographic measuring method is presented. Fifty teeth to be extracted were radiographed by means of a standardized paralleling technique and a preprinted intraoral radiographic film. The measuring grid was conveyed to the film as a latent pattern by a stenciling process prior to the x-ray exposure. The distance between the measuring lines was adjusted in accordance with the image magnification. The length of the teeth was read directly on the completed radiograph. The extracted teeth were measured by means of a sliding caliper. A statistical analysis of the data indicated that the present method is more accurate than other clinical methods commonly used for determination of tooth lengths.

Dental Instruments↗
PubMed1979

Method for radiographic assessment of alveolar bone level at endosseous implants and abutment teeth.

A radiographic method expressing the alveolar bone level in absolute figures is presented. By means of a calibrated measuring radiographic film fixed to a magnifying viewer, alveolar bone levels were determined directly on intraoral periodic "identical" radiographs. A polyether impression was made for fixation of the filmholder in order to obtain reproducible radiographs. The method was applied to assess changes in the alveolar bone level at endosseous implants and abutment teeth. Radiographs of 23 endosseous implants and 21 abutment teeth from nine patients were examined and measurements of the alveolar bone level were performed. The mean difference between double observations on the same exposure as well as on repeated exposures was about 0.2 mm (s.d. 0.17-0.32 mm). The uncertainty of the present radiographic method was mainly due to the measurement procedure, as the radiographic technique showed a high degree of reproducibility. The method is a simple and reliable technique for longitudinal investigations of changes in the alveolar bone level at endosseous implant and tooth abutments.

Alveolar Process↗