Age-Related Changes in the Orbicularis Oris Muscle and Their Implications on Aesthetic Lip Rejuvenation

Aging leads to noticeable changes in lip volume, definition, and projection largely due to alterations in the orbicularis oris muscle. Although superficial signs of aging are well-documented, deeper muscular changes remain underexplored. These anatomical shifts can influence both lip aesthetics and the effectiveness of interventions such as dermal fillers and botulinum toxin.

This study aimed to evaluate age-related changes in the angle of the orbicularis oris muscle and to examine potential sex-based differences.

Thirty healthy participants (17 women and 13 men), aged 20 to 60 years, with normal body mass index (18.5-24.9), were enrolled. None of the patients had any history of lip surgery or injections. Using high-resolution ultrasonography, the angle of the orbicularis oris muscle was measured at 5 standardized anatomical points on both the upper and lower lips.

A significant decrease in the muscle angle was observed with age, particularly in female participants. These changes were most pronounced in the upper lip and associated with a more inverted lip shape.

Age-related changes in the orbicularis oris muscle, especially in female participants, contribute to altered lip morphology. Understanding these changes can help develop more effective and natural rejuvenation strategies using injectables.