Hyperfunction of the pituitary gland in preadolescence results in

Gigantism

Explanation:

Another name of the pituitary gland is also known as the "Master gland" as it regulates and controls the other endocrine glands. The pituitary gland is  small endocrine gland and is of the size of a pea located at the brain. It performs the major biological functions :

Growth

Blood pressure

Sexual maturation

Blood pressure

It secretes the following hormones    ---

Growth hormone

Thyroid Stimulating hormone

Prolactin

Adrenocorticitropin (ATCH)

So the hyperfunction of the pituitary gland is the preadolscence age is Gigantism as it increases the growth hormone which results in growing faster.

i thinking chemical change