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.