CONSERVATIVE SCORING AND EXCLUSION OF THE PHENOMENON OF INTEREST IN LINEAR ENAMEL HYPOPLASIA STUDIES

Conservative criteria are generally employed to select only ''sufficie ntly large'' linear enamel defects to be scored as linear enamel hypop lasias (LEHs), a practice that excludes enamel defects below arbitrari ly selected size thresholds. A question arising is, are such practices likely to exclude small, yet authentic (i.e., physiological stress in duced) LEH? The permanent maxillary and mandibular first and second in cisors, canines, and first premolars on dental casts (n = 532) from a contemporary Canadian farming commune were scored for LEH, with linear defects being categorized by both breadth and width to yield the scor es A (smallest), B, C, and D (largest). Relative frequencies were calc ulated as the percent prevalence of each score per tooth divided by th e highest percent prevalence exhibited by any tooth in the same dental arch. The intertooth patterns of the relative frequencies were tested for concordance. Secondly, assuming that different researchers employ different scoring criteria, tests for concordance of mean n of LEHs/t ooth were conducted using data from four different reports as a second test for intertooth concordance of various-sized defects. Substantial concordance was observed between A, B, C, and D (Kendall's coefficien t of concordance, W = .65, P < .005) and in the interstudy comparison (W = .67, P < .01). Because it is unlikely that defects of varying siz es would have similar intertooth distributions if they did not have si milar etiologies, it may be inferred that all of the defects observed, even the very small defects, A, are variants of the same phenomenon, LEH. (C) 1995 Wiley-Liss, Inc.