背景：随着对面部除皱手术的效果要求不断提高，对眶周解剖结构的研究不断深入，眼轮匝肌外侧降肌这一独特的解剖结构被发现，国内外学者均对该肌束的解剖结构和功能进行了报道。此肌束竖直且独立走行于眼轮匝肌外侧，止于眶外侧皮下组织，收缩时有牵拉外侧眉下降的作用，参与眉下垂的形成机制，同时还与鱼尾纹的形成有关，在眶周老化改变中起重要作用。然而，此前针对该肌束的研究均是在尸体解剖的基础上完成的，目前暂无文献描述其在实际手术操作中的形态结构。

目的：本课题旨在通过在除皱手术过程中利用颞颊部切口寻找眼轮匝肌外侧降肌，探究其在手术视野下的大小、走行、起止点等解剖结构，以及功能特点和手术处理的必要性。

方法：本课题采取病例分析的形式报道了两例接受颞颊部除皱手术的患者，术中充分剥离掀起颞区皮瓣，观察记录眼轮匝肌外侧降肌的解剖结构。

结果：经颞颊部切口充分剥离皮瓣至眶外侧，可见垂直于内外眦连线走行的束带状肌性组织，上端浅出连接于皮瓣深面，下端向内下延伸。另外，在同一患者双侧颞区的相同部位，该竖直肌束的宽度和位置不相同，但共同点为该肌束在眶外侧未形成闭环，而是止于皮下组织。

结论：经颞颊部除皱手术观察颞区眼轮匝肌外侧降肌的形态结构，与此前基于尸体解剖的解剖学研究结果基本符合。通过该肌束竖直走行和止于皮下的特点，可证实该肌束具有向下牵拉外侧眉的功能。尽管该肌束较细，术中暴露要求高，对眼轮匝肌外侧降肌甚至眼轮匝肌外侧部分进行手术干预是有必要的。

Background: Nowadays, with the increasing demands for the outcome of rhytidectomy and the in-depth studies of periorbital anatomy, a unique anatomical structure called depressor orbicularis lateralis was found，which had also been reported on its anatomy and function. This muscle bundle runs vertically and independently lateral to the orbicularis oculi muscle and ends at the subcutaneous tissue of the lateral orbit. It can pull down the lateral eyebrow， which participates in the formation mechanism of eyebrow ptosis and crow’s feet, leading to periorbital aging. However, previous studies were mainly based on cadaveric anatomy, and no literatures describing the structure and function of the depressor orbicularis lateralis were found in practical surgery.

Purpose: to explore the size, course, starting and ending points of the depressor orbicularis lateralis in rhytidectomy, as well as functional characteristics and the necessity of surgical treatment.

Methods: two patients who underwent temporal and cheek rhytidectomy were reported. The temporal skin flaps were fully dissected during the operation and the morphological characteristics of the depressor orbicularis lateralis were observed and recorded.

Results: through the temporal buccal incision, when the skin flaps were fully dissected to the lateral orbital, a muscular strip can be found, which runs perpendicular to the medial and lateral canthus line with the upper end connected to the deep surface of flaps and the lower end extending medially and inferiorly.

Conclusions: the depressor orbicularis lateralis observed through temporal and cheek rhytidectomy is basically consistent with the previous studies based on cadaveric anatomy. It has the lateral eyebrow descending function and needs surgical intervention.