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 ...

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 ...

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 ...

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 ...

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. ...

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 ...

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.

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 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 ...

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 ...

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 ...

A simple radiographic measuring method was presented. Twenty endosseous implants were radiographed with the Eggen filmholder. The radiographic dimensions were determined by means of a measuring grid film fixed to the magnifying x-viewer. The grid pattern was conveyed to the film by a stenciling process. The distance between the measuring lines was adjusted in accordance with the image magnification. The implants were measured by means of a sliding caliper. A statistical analysis of the ...