Like other normal variations in the human body, tori and exostoses are categorized as bony nodular protuberances whose aetiology had been attributed early to mainly genetic theories. With a better understanding of bone mechanics, the influence of environmental factors came forward, which led to conflict between these two major etiological theories. We present a case of a mother and her son, who presented with torus mandibularis on the lingual aspect of the mandible. Drastic differences in extent and size between the two generations were observed. In Prosthodontic practice, such lesions are considered to be significant since they alter the design of the prosthesis and are also a source of bone grafts during implant placement. A cast partial denture was fabricated for the elderly female patient. Because the tori were small, they did not influence the design of the partial cast denture.
Key words: exostoses, heredity, cast partial denture, oral hygiene maintenance, malocclusion