The reason for circumcision may be religious, medical (phimosis - inability to retract the foreskin over the glans), hygienic, aesthetic, and more.
In cases where one testicle has not developed at all (agenesis), or has been surgically removed due to disease, trauma, or a position that could not be corrected surgically, the empty space in the scrotum can be filled with a testicular prosthesis to compensate for the cosmetic defect.
Penile lengthening is performed in cases of micropenis, meaning a penis shorter than 4 cm in the flaccid state and shorter than 7 cm when erect. The procedure may also be performed in men with larger dimensions when lengthening is desired.