- “Double tooth” was an old-fashioned term for the molars and bicuspids, which have the appearance of being composed of two or more joined single teeth.
- Among non-specialists, the phrase “double teeth all around” was used to refer to teeth that were exceptionally worn and appeared to be divided into multiple teeth. Such dental problems were more common in the past, before modern processing removed the grit from flour.
- The phrase “double rows of teeth” by contrast referred to a more or less perfect smile, with two perfect rows of teeth—i.e., the upper and lower set. In an era of poor dental hygiene, people with perfect teeth were especially notable.
White backs this up with examples of each use in non-giant contexts.
To his examples, I’d like to add one from the vol. 6 of the Dental Digest (1900) that explains the exasperation of dentists that even archaeologists and anthropologists (who should know better) misidentified known dental conditions as somehow representing radically different types of teeth. The excerpt below is from “Medical Abrasions of the Teeth,” a talk given by A. H. Thompson, a dentist who read this paper before the Kansas State Dental Association on May 3, 1900 after examining 2,000 ancient skulls in Philadelphia museums and finding that all had severe wear and abrasions:
The incisors and cuspids may be worn down until the cervical third, the thick portion of the crown, is reached, and the edge looks wide and grooved. This appearance has led to the popular idea of old persons having “double teeth all around,” of which we often hear. […] Inexpert observers of ancient skulls are disposed to classify the much abraded teeth as being different from the teeth of other and later races which are not so abraded. For instance, when the incisors and cuspids are worn down to the thick part of the crown near the neck and more or less notched, they are crudely described as being radically different from the teeth of Europeans, and as having “double teeth all around.” Many old travelers thus describe the worn teeth of savage people, and even recently a newspaper archeologist writes of the teeth of the ancient Cliff-Dwellers of Colorado as being different from those of later man in being “double teeth all around.” Some of the early explorers in Egypt described the teeth of the ancient mummies as being “thick at the edge,” and different from those of living races. In the collections above referred to the writer found no ancient skulls with “double teeth all around,” but did find that destructive abrasion was almost universal, the anterior teeth being often worn to the base, and showing the round section of the tooth at that point which so often misleads inexpert observers and perpetuates the popular illusion. The mistake is pardonable in the laity, but is inexcusable in anthropologists who have a knowledge of human anatomy and are exact as to the anatomical variations of other parts of the human body.
To this I must add a qualifier: The idea that giants had double teeth was not invented by ignorant Victorians but is very old. The Babylonian Talmud claimed giants had sixteen rows of teeth, and the Book of Howth reported on the double teeth of a giant around 1500. Further, the phrase “double rows of teeth” is also known to have had the meaning ascribed to them in gigantological literature. Thomas Berdmore, writing in the Treatise on the Disorders and Deformities of the Teeth and Gums (1768), asserted that there were “double rows” of teeth in the sense that modern gigantologists think of them. Pliny the Elder, writing in the Natural History (11.63) wrote of a man who had double rows of teeth in his mouth, which was different enough from normal wear for the Roman writer to remark upon.
That said, Thompson gives powerful testimony that the newspaper accounts can’t be taken at face value.