Final answer:
Onychocryptosis is the condition in which the nail grows into the edges of the nail grooves, causing an ingrown nail. It differs from fungal nail infections such as Onychomycosis and is usually a result of improper nail trimming or tight footwear.
Step-by-step explanation:
The disorder in which the nail grows into the edge of the nail grooves, causing ingrown nails, is called Onychocryptosis. This condition can be painful and may lead to infections if not treated properly. Onychocryptosis is distinct from other nail conditions such as Paronychia, which is an infection of the nail fold; Onychomycosis, a fungal infection of the nails; and Leukonychia, which are white spots on the nails.
The nail grows from a region called the nail matrix, which is a deep layer of living epidermal tissues at the proximal end of the nail. It is at the nail matrix that stem cells divide to allow for nail growth, forming first the nail root and eventually the nail plate as the nail continues to grow longer.
Fungal infections, or mycoses, can affect nails and cause various problems, such as Onychomycosis. However, ingrown nails are not caused by fungal infections but are usually due to improper nail trimming, tight footwear, or nail injury.