Abstract
Marked variations of tooth forms were encountered in two subject's mouths which strongly suggested some degenerative changes. The first case was a female aged 24 who had the upper 1st molars in both sides of jaw with a diminutive size, and these teeth appeared to have 3 cusps, because of the lack of the disto-lingual cusp, apparently by degeneration. The 2nd molars of both dental arches were more pronouncedly reduced in size than the 1st molars, and appeared flattened mesio-distally. These teeth were also three-cusped by the lack of disto-lingual cusp, and, in addition, their disto-buccal cusps showed a sign of degeneration. In this subject, the 3rd molars of both dental arches were congenitally missing and all the other upper molar teeth showed more or less general picture of degeneration. However, the remaining dentition appeared normal in the development. The 2nd case was a male of 38 years of age in whom the upper left 2nd molar was extremely diminutive like a dwarf tooth, and its crown assumed a bud-like form. The same tooth on the opposite dental arch was normally contoured except that its mesio-distal width was slightly reduced. His 1st premolar and the remaining members of whole dentition showed no sign of degeneration, and appeared rather slightly larger sized than the normal.
