"5. The malformations are unusually symmetrical and affect pairs of teeth. The two central incisors resemble each other, and the two laterals are also alike. If any defect passes horizontally across all the incisors at the same level, and affects them all alike, it is probably not due to syphilis.
"6. In syphilis the lateral incisors usually show little or no malformation.
"7. The occurrence of the peculiarities due to syphilis and those due to mercury in the same mouth are exceedingly common."
127 London Lancet, 1876, pp. 56 and 535.
128 Illustrations of Clinical Surgery, fasciculus xi., London, 1878.
The great importance of the subject seems to me to justify one more quotation, as showing the opinion at a very recent date of men well qualified to judge of the correctness or inaccuracy of these statements. Mr. C. Macnamara and Dr. Thomas Barlow129 say: "The characters of the teeth are so valuable when present that it is important to have them clearly noted—the more so that, in spite of Mr. Hutchinson's clear description, they have been much misrepresented. It may be pointed out—(1) That only the upper median permanent incisors are characteristic, and sometimes only one of them is typical, of the disease; (2) that these teeth are generally a little apart, instead of being in apposition, and are more or less dwarfed; (3) that in a typical specimen the width of the cutting edge is narrower than the width of the tooth as it emerges from the gum; (4) that a typical syphilitic tooth presents a single notch, not a serrated margin; and that occasionally, if the notch has not been actually scooped out, there is a little lunula-shaped area which may readily become a notch; (5) finally, that although such teeth, when present, are absolutely pathognomonic, the existence of normal permanent upper median incisors by no means excludes the existence of hereditary syphilis."
129 On behalf of the Collective Investigation Committee, who have issued a circular designed to elicit information as to the effect of syphilis on the civil population of Great Britain. This circular has been sent to physicians, and contains queries as to various points relating to the symptoms of inherited syphilis; among others as to the existence in any given case of "notched, dwarfed upper median incisors," which, with or without other symptoms, would establish the diagnosis of that case. The observations above quoted are explanatory of this question (The British Medical Journal, Dec. 16, 1882).
I believe this may fairly be taken to represent the general belief at the present day among those best qualified to pronounce upon the merits of the case; and I may say that it is unqualifiedly my own opinion, arrived at after some experience and considerable investigation into the literature of the subject. It is not uncommon, however, to hear doubts expressed as to the value of this sign in the diagnosis of syphilis, and at intervals articles are written or papers read to prove that it is not of the uniform and distinctively conclusive significance that has been attributed to it.130
130 "I cannot say more in favor of the diagnostic values of these teeth than that, when present in typical form, they have a certain weight in favor of the existence of hereditary syphilis in the given subject" (Van Harlingen, article "Syphilis" in Internat. Encyc. of Surgery, vol. ii. p. 565). "It has been the custom from time to time since Mr. Hutchinson made his observation to question the validity of his views, both as to the fact of interstitial keratitis being due to hereditary syphilis, and as to the diagnostic values of the so-called characteristic teeth. Thus, it has been asserted, not only in England, but on the Continent, and especially in Germany, that the disease may be the result of malnutrition in scrofulous and rickety subjects; and it has been maintained that the malformation of the teeth is the simple arrest of development in a perverted constitution from other causes than syphilis" (Bumstead and Taylor, op. cit., p. 701). Garretson says (Oral Surgery, p. 316): "Observations will be found to greatly vary concerning the existence of any constancy in phenomenal expressions of the teeth in this relation."
M. Magitot, who has for some years been supposed to pay especial attention to this subject, has recently written an elaborate paper (Gazette des Hôpitaux, Sept. 29, Oct. 4, 11, and 18, 1881) to prove (1st) that dental erosions, as he calls them, are not due to syphilis; and (2d) that they are due to, or are almost invariably associated with, infantile convulsions. He has collected a number of interesting facts, but a very careful study of his article and inspection of his diagrams have convinced me that he does not recognize at all the special peculiarities of the Hutchinson teeth, but includes under his title of "erosion" a variety of widely-differing conditions. He has altogether misinterpreted Mr. Hutchinson's views as stated in his Memoirs on Certain Diseases of the Eye and Ear due to Inherited Syphilis, and represents him as at that time (1863) believing that the cause of the change in the incisors was a mercurial stomatitis. The quotation on p. [294] sufficiently refutes this absurdity. Of course the paper as an argument against the syphilitic origin of these teeth is without the slightest value.