by Malvin E. Ring, DDS, MLS, FACD (DR. RING is author of Dentistry An illustrated History. Requests for reprints should be directed to the author at 2 Roby Drive, Rochester, NY 14618.)

Stents have been used in numerous medical disciplines, as well as in oral surgical procedures. Uses range from rebuilding mandibles and constructing new ureters, to keeping coronary arteries patent after angioplasty. The earliest use of the word listent" to describe this item was in 1916, when a Dutch plastic surgeon described how he used a dental impression compound as a matrix around which to form tissue in the process of rebuilding a shattered face. What is generally unknown is that the word "stent" derives from the name of an English dentist, who invented this impression compound in 1856.

Ask any informed lay-person what a "stent" is and the answer will generally be "a tube put into a heart artery during ballooning to keep the artery open." Ask a urologist and you'll learn that a stent is used to artificially produce a tube to replace a damaged ureter or other natural conduit. Radiologists will tell you that it is a device used by them to indicate an interventional device as part of a prosthesis.' Other branches of medicine have their own ideas of what a stent is and what it's used for, but most have no idea from where the name stems.

However, some in the medical profession are intrigued with the origin of this word "stent," and numerous articles have been published in medical journals speculating over its origin. Two English surgeons wrote:

"On seeing an advertisement for a conference to
be held in May, 1996 in Westminster entitled 'The
Stent Summit I0 Years of Stenting', the authors
were intrigued that the word should become so
commonly used in urological, cardiac and vascu-
lar surgery to describe the splinting open of a hol-
low tube or viscus. Is there a relationship and if
so, when and how did it develop?"10

The fact that it derives from the name of Charles Stent, an English dentist, would make one think that dental publications would have published some articles about its origin. (Fig. 1) But, to date, only medical journals have done so. This paper, therefore, is an attempt to inform the dental profession about its genesis.

Numerous times in the English language proper nouns have become common words and the word 11 stent" seems to be one such example. There are many others, such as guillotine (after its inventor, the French physician, Guillotin), draconian (after Draco, an Athenian statesman who drew up a severe code of laws), as well as stentorian (after the Greek messenger, Stentor, in the Trojan War, who had the "voice of 50 men") .

Stents in Surgical and Medical Practice

Mosby's medical dictionary defines a stent as "1. a compound used in making dental impressions and medical molds. 2. a mold or device made of stent, used in anchoring skin grafts and for supporting body openings and cavities during grafting of vessels and tubes of the body during surgical anastomosis."Il A recent history of medicine describes stents as "custom-built steel or hard plastic tubes [which] can be inserted under angioscopic or ultrasound guidance, to prevent the collapse of blood vessels and ducts."" Dorland's medical dictionary stresses its use as a molded appliance used to hold a graft in place or act as an obturator.' No matter the uses, the term originated with a material devised by a dentist to enable him to more easily secure better and more accurate impressions of the mouth and oral structures.18

Surgeons trained in both England and the United States during the early years of the 20th century were aware of Stent's material and its use in dentistry as well as in plastic surgery. "In the generalized training of surgeons, principles and applications of one specialty merged into another, an outcome that extended Stent's concept and Stent's dressing into other anatomic applications and hence new technologies."16

A cardiac surgeon, T. 0. Cheng, in commenting on the use of the name Stent as a noun says, "The greatest accolade that can be given to any inventor is to have the initial capital letter dropped from his name, for that is recognition that the word is now in the general language .3

Today stents are used everywhere, and the word stent has now become one of the most commonly used words in a number of medical disciplines. An investigation of MEDLINE searches for the year 1995 listed more than 500 instances in which the word stent appeared in the title or subject heading of a published article! Stents were apparently used in a large variety of procedures including nasal reconstruction; in gynecology, where different ducts and tubes had to be reconstructed; in surgery of the trachea; in plastic surgery, especially in rebuilding of the mandible; and most well-known, in cardiac surgery.1

Stents are now produced commercially by a number of firms and are most commonly made of inert metals. However, a major breakthrough occurred when a new bioabsorbable stent, sold under the trade name SpiroFlo, was introduced in 1992 by the Bionx Company of Blue Bell, Pennsylvania. (Fig. 2) This is especially useful where the stent would normally be removed when the desired reconstruction of the deficient part was completed. Another firm, MoBeta, of Los Altos, Califon-da, devised a method to make stents radioactive so that they could be more easily seen on a radiograph.

Early Use of Stent's Name

The First World War saw the introduction of trench warfare. Soldiers in the trenches were fairly well protected so long as they stayed below ground level. In order to fire their rifles, however, they had to raise themselves above the edge of the trench, and thus were very suscepable to facial wounds. The number of these disfiguring wounds was staggering, and surgeons had little experience in handling them. One Dutch physician, J. F. Esser, was designated Special Surgeon for Plastic C)perations and assigned to a hospital in Vienna. In a seminal paper he wrote:

In this war I went to Austria to help repair and undo a little part of the cruel mangling that millions of men have produced all over Europe... As I made in Austria over 700 plastic operations on war cripples, I enlarged my practical experience, especially in repairing defects of the face in an important manner .6

He then went on to describe on page 309 how he used "the mould of dentical mass (Stent's) in fixation of skin grafts in oral surgical repair of war wounds." This he accomplished by means of what he termed the "epidermic inlay technique" which used Stent's compound to stretch and fix in place grafts to enlarge the conjunctival fomices, and in ear reconstruction as well as intraoral grafting. Later, on page 311 of the same article he referred to the material he used as "stents mould."

A former English army surgeon, H.D. Gillies, cited Esser's work in his 1920 book, Plastic Surgery of the Face, when he wrote "The dental composition for this purpose is that put forward by Stent and a mould composed of it is known as a 'Stent."" This is probably the first use of Dr. Stent's name as a noun.

Notwithstanding this very obvious reference to Dr. Stent by one of the first physicians to use a "stent" and to publish a paper regarding how he came to call it that, several medical researchers still are trying to seek a more ancient source for the name. One English physician prefers the Oxford English Dictionary's definition of a stent as "a stake for stretching out fishing nets upon a river." To compare this to the use of Stent's compound as a form around which to build a tube, is stretching things indeed! 15

Another medical researcher tackling this problem of the etymology of the word seems to clinch the case when he wrote "We have been unable to find the word used in medical literature with a lower case "s" before the publication by Esser in 1917, in which the word changes from a capitalized surname to an adjective, to a common noun."13

The Contribution of Charles Stent

In the nineteenth century the principal dental impression materials were bees wax and plaster of Paris. Both had inherent weaknesses; wax distorted upon removal from the mouth, and plaster was very difficult to use. In 1847 the English dentist, Edwin Truman (1819-1905) introduced gutta percha as a denture base. 12

He patented a method of refining this crude form of rubber, and won renown when he suggested using this material as a coating for the undersea Atlantic Cable which had broken several times as a result of corrosion by sea water. His accomplishments led to his appointment as "Dentist to the Royal Household" in 1855.14

Dr. Truman tried using this gutta-percha material for impression taking, but it was unsatisfactory since it distorted during removal from the mouth and shrank upon cooling.

The breakthrough came when the London dentist, Charles Stent (1807-1885) added several other materials to the gutta-percha, notably stearine a substance derived from animal fat which markedly improved the plasticity of the material as well as its stability. He also added talc as an inert filler to give more body to the material, and red coloring. This new material, introduced in 1856, proved so successful that Dr. Stent was hailed by the dental profession. Sir John Tomes, England's great dental surgeon, lauded him for his contribution at the meeting of the Odontological Society of Great Britain in 1857.2

Dr. Stent had two sons, Charles Robert Stent and Arthur Howard Osborne Stent, who were also practicing dentists. The senior Dr. Stent's home and dental office was at 21A Coventry Street in the heart of downtown London. Here, assisted by his sons, he began producing his impression compound and marketed it under the firm name C. R. and A. Stent.

In 1885 Dr. Stent, senior, died at the age of 78 and his son Arthur moved back into the family home on Coventry Street. He and his brother, Charles Robert, continued running the business, marketing the compound through the prestigious dental supply company, Claudius Ash and Sons. When these two sons died, around 1900, Ash's firm purchased all rights to the compound and manufactured it, keeping the Stent name. (Fig. 3)

Ash's catalogue of 1871 listed "Stent's Impression Compound" at 6 shillings a pound. The 1875 catalogue, however, listed two products, "Stent's Composition," which sold in packages of six pounds, at five shillings a pound, and also "Stent's Improved Composition" which was available in pink, yellow or white, packaged in half pound boxes, and which sold for six shillings a pound.4

Dr. Stent's invention is but one in a long line of contributions made by dentists, which have benefited patents everywhere, and have advanced not only dentistry, but all of the healing arts.

The author wishes to thank Ms. Linda Lohr, Librarian, History of Medicine, Health Sciences Library, State University of New York at Buffalo, for her assistance in supplying material for this paper.

References

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4. Cohen, R. A., Leamington Spa, England, personal communication, August 14,2000.

5. Dorland's Illustrated Medical Dictionary. 27th Edition.
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7. Gillies, H. D. Plastic Surgery of the Face. London, Oxford
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10. Morgan, B. D. G. and Osborn, R. M. "What's in a word:
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11. Mosby's Medical, Nursing, and Allied Health Dictionary.
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12. Mulliken, J. B. and Goldwyn, R. M. "Impressions of
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13. O'Brien, J. C. jr. "More on the word "Stent." Amer I Cardiol 2000,85:919.

14. Ring, M. E. "From the fertile minds of dentist-,.. " Calif
Dent Assn J, 1995, 23(l): 23-28.

15. Sigwart, U. "What is a Stent and where can you get one?" Amer j Cardio, 1997, 80: 1122.

16. Sterioff, S. "Etymology of the word "stent." Mayo Clin
Proc 1997, 72: 377-79.

17. Van Urk, H. "Repairing the body" in Duin, N. and
Sutcliffe J. A History of Medicine from Prehistory to the
Year 2020. London, Morgan Samuel, 1992, p. 235.

18. Ward, G. "Impression materials and impression taking."
Brit Dent j 1961,110: 118-119.