Is it permissible to perform a breast augmentation operation with a small implant to remove a defect, or can a larger implant be used to improve appearance, taking into account that both do not cause harm and are not considered an alteration of Allah's creation?

Breast augmentation surgery for a woman, if it is to remove a defect or deformity, such that their small size is abnormal, then there is no objection to it. However, it should be limited to the extent that removes the defect and restores the breast to the normal size among most women. Exceeding that is not permissible, because what is permitted due to necessity is estimated by its measure.