The Orbicularis Oculi Muscle Neuroanatomical Research And Its Application In Cosmetology

Objective:To investigate the anatomic law of nerve that dominates orbicularis oculi muscle, in order to present anatomy evidence for creotoxin precise location injection in cosmetic surgery, reduce the dosage of medicine and enhance sense of aesthetics.Methods:31 adult head specimens (46 sides, with some specimens in which there’s only one side or damaged) that has been embalmed by 10% formalin solution, including 24 left sides and 22 right sides. The number of male specimens is 28 (42 sides) and female is 3 (4 sides). The researcher simulates microsurgery under the microscope and anatomises from the skin to facial muscles such as orbicularis oculi muscle, frontalis muscle, zygomaticus major, zygomaticus minor and levator labii superioris etc., as well as separate Facial nerve temporal and zygomatic branch and their secondary branch.(1) Observe the route and branch of temporal and zygomatic nerve, as well as the law of entering orbicularis oculi muscle.(2) Taking outer canthus as original point, the line between the midpoint of tragus and outer canthus as horizontal axis, the line across outer canthus and perpendicular to the line before as vertical axis, measure the distance between point entering muscle of facial nerve temporal and zygomatic branch and outer canthus as well as the intersection angle with horizontal axis using vernier caliper (with precision of 0.02 mm) and protractor (with precision of 1°).(3) Devise the best injection spot of crow’s feet rhytidectomy in cosmetic surgery and compare with traditional cosmetic methods.Results:(1) The number of temporal branch at orbicularis oculi muscle’s point entering muscle is 2 to 6 on the left side and the average number is 3.92±1.18. The point where left temporal branch entering orbicularis oculi muscle is averagely 36.67 ±3.93 mm away from ipsilateral outer canthus, and the intersection angle is -4°～53°. The number on the right side is 2 to 6 and the average number is 3.91±1.06. The point where right temporal branch entering orbicularis oculi muscle is averagely 38.38±5.60 mm away from ipsilateral outer canthus, and the intersection angle is-10°～48.8°. The most common number of branch that temporal branch on both sides entering orbicularis oculi muscle lateral border is 3 to 5, and 6 is relatively rare. There are 94 temporal branches on the left side entering orbicularis oculi muscle, with 80 of them within the scope of 0～30°, which takes up 85.12% of all. The number on the right side is 86, with 69 of them within the scope of 0～30°, which takes up 80.23% of all. The number of zygomatic branch at orbicularis oculi muscle’s point entering muscle is 1 to 5 on the left side and the average number is 2.61±1.03. The point where left zygomatic branch entering orbicularis oculi muscle is averagely 40.26±2.76 mm away from ipsilateral outer canthus, and the intersection angle is-9°～-48.5°. The number on the right side is 1 to 5, and the average number is 2.70± 1.08. The point where left zygomatic branch entering orbicularis oculi muscle is averagely 40.09± 4.26 mm away from ipsilateral outer canthus, and the angle is 0～-48.5°. The most common number of branch that zygomatic branch on both sides entering orbicularis oculi muscle lateral border is 2 to 3, and 5 is relatively rare. There are 60 zygomatic branch on the left side entering orbicularis oculi muscle, with 57 of them within the scope of 0～30°, which takes up 95.0% of all. The number on the right side is 54, with 46 of them within the scope of 0～-30°, which take up 85.19% of them.(2) According to the facial nerve in the temporal, zygomatic branch into the distribution of muscle damage can design clinical botulinum toxin injections "three", distances on the left side are 38.07±4.46mm,39.59±3.79 mm and 42.23±4.43 mm, and the angles accordingly are 18.9°±5.5°,1.2°±5.5° and -17.1°±4.7°. Distances on the right side are 39.23±5.38 mm,40.41±3.90 mm and 42.30±4.38 mm, and the angles accordingly are 18.4°±6.3°,0.9°±5.6° and -17.3°±5.3°. Based on the condition of wrinkles, inject 2-2.5 u botulinum toxin A on each spot and the effect start to present in 1 to 7 days, then in a month the best result can be seen. The researcher reviews the effects in 1 week,2 weeks,4 weeks and 12 weeks with standardized photography to compare rhytidectomy effect with traditional injections. It shows that the rhytidectomy effect of experimental group is quite distinct and the appearance looks natural.Conclusion:Based on the microanatomy on route and distribution of facial nerve temporal and zygomatic branch as well as entering orbicularis oculi muscle, the measure of distance and angle of nerves entering point entering muscle of orbicularis oculi muscle, clinically botulinum toxin A can be in injected at 3 fixed spots within the scope of ntering point entering muscle of orbicularis oculi muscle.And clinical practice, confirmed that "three injections" anti-wrinkle effect is obvious, natural appearance, after compared with the traditional "five injections" anti-wrinkle effect and maintaining time has no obvious difference, but significantly reduced dosage of botulinum toxin, reduce the patient pain, is worth further study and promotion in clinical.