cortices. 1  1a (1) : the outer or superficial part of an organ or bodily structure (such as the kidney, adrenal gland, or cerebellum or a bone); especially : cerebral cortex (2) : the proteinaceous usually pigmented layer of a hair below the cuticleb : the outer part of some organisms (such as paramecia)
If a toenail has completely fallen off, it can take up to 18 months for it to grow back. A toenail can take longer to grow back if the nail bed has permanent damage. In some cases, old nails do not completely fall off, and they act as a protective...
Commonly, toenail is going to regrow very slow and may elapse a 12 to 18-month period. If your toenail partly falls off from traumatic injuries or sports, leaving a small portion of the nail, but not permanent damage to the nail bad, the nail still has got a chance of growing back within 6 to 9 months.