102 



R. F. SOGNNAES 



Fig. 1. Variability in the gross morphological distribntion ot dciita] erosion: 

 A, B, narrow horizontal grooves; C, D, E, shallow, flat, and disc-shaped; F, 

 irregular horizontal and vertical erosion separated by intact tooth; G, figured; 

 H, I, circumscribed, wedge-shaped, labial (H) and lingual (I). For details 

 see text. 



edge, in others near the gingival margin, in others at both sites. In 

 some mouths there are combinations of lesions running horizontally 

 and vertically, and yet separated by completely unaffected teeth 

 (Fig. IF). This would be extremely difficult to account for on the 

 basis of tooth brushing. Occasionallv extreme lesions can be seen 

 lingually in the gingival area of the lower anterior teeth, a location 

 completely incompatible with a tooth-brushing etiology. In one such 

 case, shown in Fig. 1 1, the erosion ultimately progressed so far 

 that the destruction circumscribed the whole cervical area, both 

 lingually, interproximally, and labiallv, so as to produce an hour- 

 glass appearance interestingly similar to a natural rock "erosion" 

 ( see Fig. 2 with insert ) . 



The several examples of dental erosion shown in Fig. lA to I con- 

 form (from the point of view of gross topography) to the classical 

 description of G. V. Black, as retained in later textbooks (Black, 

 1936 ) , including narrow horizontal grooves (A, B ) , disc-shaped and 



