There is an approximate time of epiphyseal closure, especially for height-related epiphyses, which are usually closed by the age of 25, such as the epiphysis of the human spine and pelvis, which are the latest epiphyses to close in relation to height. The epiphysis that is not related to height may not close until after 30 years of age. There are also rare epiphyses that remain unclosed throughout a person’s life, and this is a minority of cases. 25 is the latest age at which most epiphyses close, while some people with relatively abnormal bone development may experience early closure of the epiphysis, that is, people with relatively young bone age, or people with delayed bone development, may have their height-related epiphysis close when they are about 20 years old. The epiphysis may close completely at the age of 20.