H. T. Dean´s epidemiology of mottled teeth (dental fluorosis)

H. T. Dean´s epidemiology of Mottled Teeth

The following classifications of mottled teeth were published by Henry Trendley Dean, D.D.S., of the U. S. Public Health Service, in 1934, 1935, 1938 and 1942:

Category	1934 (1)	1935 & 1938 (2,3)	1942 (4)
Questionable	slight aberrations in translucency, ranging from a few white flecks to occasional white spots, 1 to 2 mm in diameter	slight aberrations in the translucency ranging from a few white flecks to occasional white spots; in some instances, thin irregular, white, opaque streaks, or veining on the incisal third of the superior incisors; in other cases the tip of the summit of the bicuspids shows unusual white opacity 2 or 3 mm in extent, while remainder of tooth apparently normal	slight aberrations in translucency, ranging from a few white flecks to occasional white spots
Very mild	small opaque paper white areas scattered irregularly or streaked over the tooth surface; principally observed on the labial and buccal surfaces; involves less than 25 per cent of tooth surface; small pitted white areas frequently found on summit of cusps; no brown stain present in mottled enamel of this classification	small, opaque, paper-white areas scattered irregularly or streaked over the tooth surface; principally observed on the labial and buccal surfaces, involving up to 25 percent of tooth surface; small pitted white areas frequently found on summit of cusps; brown stain rarely observed in mottled enamel of this classification and, if present at all, is so faint as to be almost indistinct	small opaque paper white areas scattered irregularly or streaked over the tooth surface; involves less than 25 per cent of tooth surface; frequently included in this classification are teeth showing no more than about 1-2 mm of white opacity at tip of summit of cusps, bicusps or second molars
Mild	white opaque areas involve at least half of the tooth surface; surfaces of molars, bicuspids, and cuspids subject to attrition show thin white layers worn off and the bluish shades of underlying normal enamel; faint brown stains sometimes apparent, generally on upper incisors	white opaque areas involve at least half of the tooth surface; surfaces of molars, bicuspids and cuspids subject to attrition show thin white layers worn off and bluish shades of underlying normal enamel; light brown stains sometimes apparent, generally on superior incisors	white opaque areas more extensive but do not involve as much as 50 per cent of tooth
Moderate	no change in form of tooth, but generally all tooth surfaces involved; surfaces subject to attrition definitely marked; minute pitting often present, generally on labial and buccal surfaces; brown stain frequently a disfiguring complication; "It must be remembered that the incidence of brown stain varies greatly in different endemic areas, and many cases of white opaque mottled enamel, without brown stain, are classified as moderate and listed in this category"	no change in form of tooth, but generally all tooth surfaces involved; surfaces subject to attrition definitely marked; minute pitting often present, generally on labial and buccal surfaces; brwon stain frequently a disfiguring complication; stain ranging for most part from tan to chocolate in color and not infrequently involves as much as half of labial surface; "It must be remembered that the incidence of brown stain varies greatly in different endemic areas, and many cases of white opaque mottled enamel, without brown stain, are classified as moderate and listed in this category"	all enamel surfaces of the teeth affected; surfaces subject to attrition show marked wear; brown stain frequently a disfiguring feature
Moderately-severe	greater depth of enamel apparently involved; smoky white appearance often noted; pitting more frequent and generally observed on all tooth surfaces; brown stain, if present, generally deeper in hue and involves more of the affected tooth surfaces	greater depth of enamel apparently involved; smoky white appearance often noted; pitting more frequent and generally observed on all tooth surfaces; pits discrete and may be 1 to 2 mm in diameter; brown stain, if present, generally deeper in hue and involves more of the affected tooth surfaces; "the diagnostic sign of this classification is, however, the discrete pitting	-- this classification no longer used --
Severe	hypoplasia so marked that form of tooth at times affected; condition in older children a mild pathologic incisal-occlusal abrasion; pits deeper and often confluent; stains are widespread and range from chocolate brown to almost black in some cases	hypoplasia so marked that form of tooth at times affected; condition in older children a mild pathologic incisal-occlusal abrasion; pits deep and often confluent; as result of confluent pitting, which is diagnostic sign of this classification, outer surface of enamel lost in places and tooth often presents corroded-like appearance; stains are widespread and range from chocolate brown to almost black	includes teeth formerly classified as "moderately severe" and "severe"; all enamel surfaces affected and hypoplasia so marked that general form of tooth may be affected; major diagnostic sign of this classification is the discrete or confluent pitting; brown stains are widespread; teeth often present a corroded-like appearance

Neither of the descriptions that followed the 1934 paper by Dean (1) was meant as a revision, rather they were intended to be "brief descriptions" (2) of the first classification. It will appear from these descriptions that there were some uncertainties in Dean´s mind: The "very mild" category as described in 1934 shows "no brown stain" while according to the 1935 and 1938 descriptions brown stain is "rarely observed" and "faint" (as it was in the "mild" category described in 1934); in 1942, brown stain.appears only in the descriptions of the "moderate" and "severe" categories. White spots 1 - 2 mm in diameter were rated in the "questionable" category in 1934, in the "very mild" category in 1942, while the "questionable" rating in 1935 and 1938 already mentioned white opacities 2 to 3 mm in diameter (2,3). These discrepancies are important since the different ratings are given numerical values used to calculate the Community Fluorosis Index.

Both the 1934 and 1935 papers are illustrated with the same figures. Dean had plenty of photographs by the time, yet to illustrate his papers he did not publish photographs but drawings which do not show actual details of mottled teeth but a "medical artist´s concept". They were "developed", Dean admitted in 1952 at Hearings before the House Select Committee to investigate the use of chemicals in foods and cosmetics (5), not as a proper presentation to the public but "somewhat of an exaggerated condition in order to depict these different points." Public Health people often overemphasize certain things to make a point, Representative Miller explained such behavior. However, in the 1942 description Dean apparently preferred the other extreme - downgrading, as appropriate to sell the fluoridation idea.

References:

(1) Dean H. T .: "Classification of mottled enamel diagnosis"; JADA 21 (Aug. 1934) 1421; (2) Dean H. T., Dixon R. M., Cohen C.: "Mottled enamel in Texas", Publ. Health Rep. 50 (1935) 424; (3) Dean H.T.: "Chronic endemic dental fluorosis (Mottled Enamel)", Chapter XII in S. M. Gordon (ed.), "Dental Science and Dental Art", Philadelphia, 1938, p. 387; (4) Dean H. T.: "The investigation of physiological effects by the epidemiological method", in F. R. Moulton (ed.): "Fluorine and dental health", AAAS, Washington, 1942, p. 23; (5) Dean H. T.: House Select Committee to investigate the use of chemicals in foods and cosmetics: "Chemicals in Foods and Cosmetics", Hearings before the House Select Committee to investigate the use of chemicals in foods and cosmetics, House of Representatives, 82nd Congress, 2nd session, pursuant to H. Res. 74 and H. Res. 447, Part 3, Washington 1952, pp. 1646-1647;

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