Areal roughness of the dorsal nail plate

Abstract

Beau’s lines, onychorrhexis, and psoriatic lesions of the dorsal nail plate may be missed by photographic methods, indicating a need for surface texture measurement methods that are more quantitative, sensitive, and repeatable than visual inspection or imaging. We conducted this study to evaluate the utility of surface texture measurements of cadaveric nails that can be associated with histopathological studies in the future. The nail plates of four cadaveric right pollices and halluces were cleaned and molded, cast in clear epoxy, and scanned with a Sensofar S Neox optical profilometer. A one-way analysis of variance (ANOVA) was performed to determine statistical significance of findings. Almost no differences were observed between the pollex and hallux scans, and between the distal and proximal regions. The greatest differences were found between individuals. Although lower magnification (5×) is less sensitive than higher magnification (20×), the lower magnification represented and characterized more of the dorsal nail plate. The dorsal nail plate areal roughness has a measurable range of values that may serve as a starting point for evaluating pathological findings, particularly Beau’s lines and psoriatic lesions. The sensitivity of these techniques may be especially valuable in the recognition of less severe states of these diseases that may enable the diagnosis of earlier stages of growth disruptions (Beau’s lines) or psoriasis. Such applications could be especially useful in investigations of the health of wildlife populations or vulnerable human populations with incomplete treatment records.