[1] Just as it is impossible to define 'normal' breast size, there is no objective definition of micromastia.

This condition may be a congenital defect associated with underlying abnormalities of the pectoral muscle (as in Poland's syndrome[2]), related to trauma (typically surgery or radiotherapy) or it may be a more subjective aesthetic description.

Societal ideals over breast size vary over time, but there exist many conceived ideas involving breasts and sexual attractiveness and identity across different cultures.

[3] Acquired causes of micromastia include irradiation in infancy and childhood and surgical removal of prepubertal breast bud.

Other techniques available involve using muscle flap-based reconstructive surgery techniques (latissimus dorsi and rectus abdominis muscles), microsurgical reconstruction, or fat grafting.