Functional and Volumetric Analysis of the Pectoralis Major Muscle After Submuscular Breast Augmentation.

[BACKGROUND] Dual plane breast augmentation is a technical variation of the submuscular plane described as a technique that reduces contour deformities due to contraction of the pectoralis major muscle and lower risk of double-bubble deformity associated with breast ptosis. Despite improvement in the aesthetic aspect, there is still no consensus whether this technique affects the function of the pectoralis major muscle.

[OBJECTIVES] The aim of this study was to correlate functional with volumetric changes associated with dissection of the muscle origin in submuscular breast augmentation.

[METHODS] Thirty women who desired to undergo breast augmentation were selected prospectively and randomly allocated to 2 groups: 10 patients in the control group and 20 patients in the interventional group, who underwent submuscular breast augmentation. Magnetic resonance imaging and volumetric software were used to assess muscle volume and isokinetic dynamometry was used to assess function of the pectoralis major muscle. Preoperative measurements were compared with those at 3, 6, and 12 months after surgery.

[RESULTS] Magnetic resonance imaging revealed significant decrease in muscle volume at 6 and 12 months follow-up. The isokinetic test conducted during adduction showed a significant difference in muscle strength between groups from baseline to the 12-month follow-up, and between the 3- and 12-month follow-up. No significant differences in muscle strength during abduction were observed from baseline to the 3-, 6-, and 12-month follow-up.

[CONCLUSIONS] Submuscular breast augmentation reduced muscle strength during adduction 12 months after surgery, but without a significant correlation with volumetric muscle loss.