This is the first study devoted to the histologic and histochemical characteristics of the orbicularis oculi muscle in children to the authors' knowledge. The orbicularis muscle was compared with extraocular, facial, and limb striated muscle. Light microscopy showed the orbicularis oculi muscle to be much smaller and more loosely packed than skeletal limb muscles. It further showed these muscle...

OBJECTIVE The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and fronta...

Lower Eyelid Orbicularis Oculi Myocutaneous Flap: A Feasible Technique for Full Thickness Upper Reconstruction

This study compared the orbicularis oculi muscle to the adductor pollicis muscle during vecuronium blockade. The orbicularis oculi muscle was found to be more resistant to and recovered from vecuronium neuromuscular blockade faster than the adductor pollicis muscle. Thus, caution should be utilized when assessing neuromuscular block with the orbicularis oculi muscle.

[Purpose] This study compared the orbicularis oculi muscle activity during computer work with single and dual monitors. [Subjects] Ten computer workers 22-27 years of age were included in this study. [Methods] Subjects performed computer work with single or dual monitors, and the activity of the right orbicularis oculi muscle was measured with a MP150 system. [Results] The muscle activity of th...

The discharge profiles of identified abducens, accessory abducens, and orbicularis oculi motoneurons have been recorded extra- and intracellularly in alert behaving cats during spontaneous, reflexively evoked, and classically conditioned eyelid responses. The movement of the upper lid and the electromyographic activity of the orbicularis oculi muscle also were recorded. Animals were conditioned...

OBJECTIVE To investigate the anatomophysiologic aging-related changes in the orbicularis oculi muscle. METHODS We examined the full-thickness histologic characteristics of the upper eyelids from cadavers of 30-, 40-, 60-, and 70-year-old men and the muscle interference pattern (IP) of 68 healthy volunteers of both sexes aged 18 to 73 years. RESULTS Histologic analysis revealed that in the a...

OBJECTIVE To determine whether monitoring facial nerve motor-evoked potentials (FNMEPs) elicited by transcranial electrical stimulation during microvascular decompression (MVD) for hemifacial spasm (HFS) is useful for predicting postoperative outcome. METHODS The authors analysed FNMEP findings in 25 patients with HFS. Corkscrew electrodes positioned at C3 or C4 and Cz were used to deliver su...

PURPOSE This study examined the subacute myotoxic effects of injection of the local anesthetic bupivacaine on the orbicularis oculi muscle in the rabbit eyelid. In contrast to other muscles, the orbicularis oculi was resistant to injury by the usual anesthetic doses of bupivacaine when local infiltration is used. An attempt was made to assess the sensitivity of orbicularis oculi muscle to bupiv...

OBJECTIVE This study was conducted to investigate the success rate of using the facial motor evoked potential (FMEP) of orbicularis oculi and oris muscles for facial nerve function monitoring with use of a stepwise protocol, and its usefulness in predicting facial nerve outcome during cerebellopontine angle (CPA) surgeries. METHODS FMEPs were recorded intraoperatively from 60 patients undergo...