Innervation of the procerus muscle.

The aim of this study is to elucidate innervation of the procerus muscle, which is attributed mainly to transverse lines on the radix nasi and indirectly to glabella frown line. Twenty-three hemifaces of Korean adult cadavers were dissected. In all specimens, the procerus muscle was supplied by the buccal branch of the facial nerve, which coursed infraorbitally. The number of the buccal branches varied: three in 47.8%, two in 47.8%, and one in 4.4% of the specimens. The buccal branch crosses the intercanthal line (nasion to the medial canthus) at approximately lateral one third. The nerve entrance was within a circle with a diameter of 5 mm and its center located 9 mm lateral and 10 mm superior from nasion. It was about a midpoint of lateral half of intercanthal line and lower one third between the intercanthal line and tangential line of the supraorbital rim. The anatomical knowledge might be contributive to depletion of transverse lines on the nasal bridge and function of the procerus muscle.