Anatomocosmetic implication rules of the corrugator supercilii muscle for youthful eye appearance

The dynamic balance of the eyebrows is maintained by the frontal muscle which acts as a brow elevator, and the brow depressors include corrugator supercilii muscle (CSM), procerus, depressor supercilii, and orbicularis oculi muscles. The glabellar rhytids might appear as a result of negative emotions, such as anger, anxiety, fatigue, fear, or disapproval. For youthful and calmer eyes, CSM may restore the muscle balance more safely and effectively for the treatments of forehead rejuvenation. In 50 cadaver hemibrows, CSM was dissected to investigate the location, position, muscle patterns, and its relationships to other muscles. The location of the CSM was variable; five different CSM patterns were defined. Pattern 1: rectangular-shaped classical type was observed with the frequency of 42.5 %. Also, three bellies were present in 25 %, and duplicate muscle in 12.5 %. Irregular flat (15 %) and hypoplastic types (5 %) were introduced as previously unidentified patterns. In muscle specimens, 30 % had complete symmetry, 45 % complete asymmetry, and 25 % semi-assymetry. Mean CSM thickness, length, and width were measured as 1.62 ± 0.4, 29.24 ± 6.4, and 12.62 ± 3.3 mm, respectively. The distances of the medial origo of the CSM-midline and the lateral origo of the CSM-midline were measured as 5.54 ± 4.89 and 14.62 ± 4.17 mm. The different patterns of the CSM were undefined previously. The findings manifest the necessity of botox treatment peculiar to each individual. As, insertion points have been releasing fibres to the peripheral muscles, it is an evidence of its complicated structure. The muscles in the glabella are difficult to demarcate precisely from surface anatomy due to overlapped muscles with intermingled borders, where they are attached as individual patterns. Hence, it might be disadvantageous that different patterns may lead to the risk of asymmetry of the face and brow ptosis in the postinjection period.