NAIL GROWTH MEASUREMENT EMPLOYING NAIL INDENTATION - AN EXPERIMENTAL FOLLOW-UP-STUDY OF NAIL GROWTH IN-SITU

Nail growth was studied over 20 weeks in five healthy volunteers by in denting eight nails in each subject with a dental burr. The indentatio ns were drilled in the middle part of the lunula with the proximal edg e of the indentation 1 mm from the cuticle. Their volume was measured by filling them with an elastic two-component material immediately aft er indentation and 4, 8, 12, 16 and 20 weeks thereafter. Nail growth a s reflected by the volume changes of the indentations could be followe d for 8-12 weeks in the thumb, the middle finger and the second toe an d for 20 weeks in the big toe. The most rapid outgrowth, 8-12 weeks, o ccurred in the second toe and middle finger. The decrease in the volum e of the indentations by approximately 30-35%, as they travelled from the lunula towards the distal end of the nail plate, also reflects nai l growth from the nail bed. This study has shown that indentation of t he nails and the measurement of their volume changes provides a reliab le and simple method for the study of nail growth.