Pincer nail (PN) refers to an excessive transverse curvature of the nail plate [1, 2]. The overcurvature progresses from proximal to distal, following the nail plate longitudinal axis, resulting in impingement of the distal nail bed [1–3]. The condition most commonly affects the hallux toenails [4]. In 2001, Baran et al. [1] noted that PNs occur from an osteophyte at the base of the distal phalanx elevating the nail plate and causing the lateral nail margins to roll inward. More recently, it has been suggested that osteophyte formation at the distal phalanx is not the cause of PN, but rather a consequence of the nail plate overcurvature [5, 6]. This theory is supported by the differing physical properties of the “hard” dorsal nail plate and the “plastic” ventral nail plate [7]. An unknown factor is thought to cause shrinkage or constriction of the nail bed, affecting the ventral nail plate, but not the dorsal nail plate. The difference between the affected ventral site and unaffected dorsal site causes an inward twisting of the lateral nail margins that exerts traction over the distal tuft of the distal phalanx, resulting in osteophyte formation [3, 6, 7]. PN is distinct from onychocryptosis, a symptomatic condition in which the nail plate shape remains unchanged [6, 8].