Anatomical investigation of levator palpebrae superioris muscle and the distribution pattern of oculomotor nerve

Purpose This study aims to evaluate the morphological features of the levator palpebrae superioris muscle (LPS) and the variations in the distribution of the oculomotor nerve in the muscle. Methods 100 bilateral orbits from 50 cadavers were included in our study. In our study, the medial, lateral, and middle length, width, and thickness of the LPS were measured from 3 different points and recorded. In addition, the number of branches of the oculomotor nerve entering the LPS muscle was calculated. Results The medial, lateral, and middle length of LPS were 34.85±5.30 mm, 34.62±5.67 mm, 35.77±5.31 mm on the right side and 33.66±4.74 mm, 33.81±4.83 mm, 34.54±5.14 mm on the left side, respectively. The width of the muscle was seen to expand from proximally to distally. It was noted that the middle 1/3 thickness of the LPS was the thickest part of the muscle compared to the other parts. A total of 239 oculomotor branches entered the LPS. The middle 1/3 of the LPS was reached by 151 oculomotor nerve branches. It was noted that the largest number of oculomotor nerves entered the middle 1/3 part of LPS. Conclusion The morphometric and morphological findings of LPS and branches of the oculomotor nerve may be useful in surgical planning for the LPS and levator aponeurosis and in preventing complications during surgical interventions.