Fluoride Action Network


THE endemic hypoplasia of the permanent teeth known in this country as mottled enamel was first reported by Eager in 1901. The first investigation in the United States was the extensive one of Black,2 and McKay,3 published in 1916. At present in this country alone there are more than 200 areas where endemic mottled enamel has been confirmed by survey; in addition there are approximately 100 areas where the endemicity has been reported but not confirmed by survey. These approximate 300 areas are distributed among 23 different states.

The incidence of affection in an endemic area is relatively high, often 90 per cent, and in some instances all children exposed throughout the period of calcification of the teeth are affected. In the light of present knowledge, mottled enamel is a water-borne disease associated with the ingestion of toxic amounts of fluoride present in the water used for drinking and cooking during the period of tooth calcification. The minimal threshold has not yet been definitely established but studies to date would suggest that amounts below 1 p.p.m., expressed in terms of fluorine (F), are of no public health significance.

There is apparently no race, color, or sex differential. With respect to the teeth, the causative factor is operative only during the period of calcification, which, with the exception of the third molar represents approximately the first decade of life. There is some indication4 that the skeletal system might likewise be affected; if this is true, it would be necessary to extend the time range to include adults.

The macroscopic pathology in the human has been classified according to severity thus: normal, questionable, very mild, mild, moderate, moderately severe, and severe. These various, gradations have previously been described.5 This classification, depending on the degree of severity of the affection, permitted in turn the development of the following ” mottled enamel indexes” of a community6, 7: negative, border-line, slight, medium, rather marked, marked, and very marked. Several detailed studies 8, 9, 10 concerning the histopathology of this, disease have been reported. An analogous hypoplasia developed under natural conditions has been observed in certain domestic animals.11, 12 The sole hope in the solution of this problem lies in prevention. Since the ameloblasts cease functioning at the time of eruption of a tooth, such ameliorative treatment as is possible is naturally very limited in scope and generally unsuccessful. Bierring13 in referring to this disease recently has recorded that ” although different in nature from typhoid fever, [it] represents a permanent physical defect of distressing character.”

Mottled enamel has Mottled enamel has direct relation-ships to other forms of oral pathologysome of these relationships being at times paradoxical. In spite of their defective structure, mottled enamel teeth, according to McKay,14 exhibit no greater liability to caries than do normally calcified teeth, an inference apparently sustained by the investigations of Masaki,15 Ainsworth,9 and Erausquin.6 Masaki15 and Ainsworth,9 in addition, maintain that the eruption of the secondary dentition is delayed.

From observations made by one of us (HTD) in areas of relatively `high-fluoride concentration (more than 4.0 p.p.m.) there is, likewise, sufficient evidence to suggest an apparent tendency to a higher incidence of gingivitis (Figure I).


This paper presents a comparison of the results obtained in the investigation of the following 10 cities: Monmouth and Galesburg, Ill.; Colorado Springs and Pueblo, Colo.; Lubbock, Amarillo, Plainview, and Big Spring, Tex.; and Conway and Mullins, S. C. The detailed results, including chemical analyses, noted in the study of the Illinois and Colorado areas have been reported.7 An approximate mottled enamel index of each of the 4 Texas cities has already been reported,8 but the chemical data are included in the present paper. Furthermore, there are included in this report, for comparative purposes, chemical findings of and certain relevant clinical observations from a recently made study in South Carolina…


1. Eager, J. Al. Denti di Chiaie (Chiaie teeth). Pub. Health Rep., 16, 44 (Pt. 2:2576-2577 (Nov. 1), 1901.

2. Black, G. V. (in collaboration with McKay, F. S.). Mottled Teeth-An Endemic Developmental Imperfection of the Teeth, Heretofore Unknown in the Literature of Dentistry. Dental Cosmos, 58, 129-156 (Feb.), 1916.

3. McKay, F. S. (in collaboration with Black, G. V.). An Investigation of Mottled Teeth. Dental Cosmos, 58, 477-484 (May); 627-644 (June); 781-792 (July); 894-904 (Aug.), 1916.

4. Boissevain, C. H., and Drea, W. F. Spectroscopic Determination of Fluiorine in Bones, Teeth, and other organs, in Relation to Fluorine in Drinking Water. J. Dent. Res., 13:495-500 (Dec.), 1933.

5. Dean, H. T. Classification of Mottled Enamel Diagnosis. J. Am. Dental Assn., 21:1421-1426 (Aug.), 1934.

6. Dean, H. T., Dixon, R. M., and Cohen, C. Mottled Enamel in Texas. Pub. Health Rep., SO: 424-442 (Mar. 29), 1935.

7. Dean, H. T., and Elvove, E. Studies on the Threshold of the Dental Sign of Chronic Endemic Fluorosis (Mottled Enamel). Pub. Health Rep., 50:1719-1729 (Dec. 6), 1935.

8. Williams, J. L. Mottled Enamel and Other Studies of Normal and Pathological Conditions of this Tissue. J. Dent. Res., 5:117-195 (Sept.), 1923.

9. Ainsworth, N. J. Mottled Teeth. Brit. Dent. 1., 55:233-250 (Sept.), 1933, disc. 274-276.

10. Erausquin, R. Dientes veteados (cuarta communicaci6n). Revista Odontoldgica (Buenos Aires), 22:430-441 (Aug.), 1934.

11. Velu, H. Le Darmous (ou Dermes). Arch. d. Inst. Pasteur der PAlgerie, 10, 1:41-118 (Mar.), 1932.

12. Dean, H. T. Mottled Enamel in Cattle. Pub. Health Rep., 50:206-210 (Feb. 15), 1935.

13. Bierring, W. L. State Dept. of Health (Mottled Enamel of Teeth in Iowa). J. Iowa M. Soc., 24:450-451 (Aug.), 1934.

14. McKay, F. S. The Establishment of a Definite Relation between Enamel That Is Defective in Its Structure, as Mottled Enamel. and the Liability to Decay. (II), Dental Cosmos, 71:747- 755 (Aug.), 1929.

15. Masaki, Tadaihi. Geographical Distribution of ” Mottled Teeth ” in Japan. Shikwa Gakuho, 36 (Oct.), 1931.

16. Erausquin, R. Dientes veteados (quinta communicaci6n). Revista Odontoldgica (Buenos Aires), 23:296-313 (May), 1935.

17. Kempf, G., and McKay, F. S. Mottled Enamel in a Segregated Population. Pub. Health Rep., 45:2923-2940 (Nov. 28), 1930.

18. Elvove, E. Estimation of Fluorides in Waters. Pub. Health Rep., 48:1219-1222 (Oct. 6), 1933.

19. Foote, F. J. Determination of Boron in Waters. J. Indust. Eng. Chem., Anal. Ed., 4:39-42 (Jan. 15), 1932.