What are the differences in the results of different levels of breast augmentation? There are four different levels of breast augmentation: posterior pectoralis muscle gap; posterior areola gap; dual plane method; and subfascial pectoralis muscle. The posterior pectoralis muscle space is located between the pectoralis major and pectoralis minor muscles and the implant can be placed at this level through various incisional approaches. Because the gap is very easy to peel, the operation is relatively simple, is the most traditional and most commonly used level of implantation, the disadvantage of the level is: when the muscle force will feel hard, and even the contour of the unnatural. However, implant placement into the posterior space of the pectoralis major muscle allows the implant to obtain good tissue coverage and makes the transition to a natural contour of the upper pole of the breast, which is the only option for patients with particularly thin subcutaneous fat. The posterior mammary gap is located in the tissue gap between the breast and the pectoralis major muscle and completely avoids the disadvantages of the posterior pectoralis major muscle gap, but is only suitable for patients with thick breast tissue and subcutaneous fat. Some research data show that the chance of contracture at this level is higher. This level combines the advantages of the posterior pectoralis muscle and the posterior mammary gland gap, and avoids the disadvantages of each, which is a very ideal level for prosthesis placement. However, this level cannot be done through the axillary incision under blind vision, but must be done through endoscopic techniques or other incisions, and cannot be used for patients with thin mammary glands and subcutaneous fat. The pectoralis major subfascial plane has similar advantages to the posterior mammary space level, and the pectoralis major fascia may provide good coverage of the prosthesis, but it is difficult to peel off at this level and requires high technical requirements, and is only suitable for women with thick areolar tissue and subcutaneous fat. It is important to note that the level of implant placement is usually determined by the surgeon based on the patient’s subcutaneous breast tissue conditions and the surgeon’s technical skills.