口角轴的解剖学基础

Elementary anatomy of the facial modiolus

目的：通过对口角轴的大体解剖，了解口角轴的位置及参与肌的形态学特点等，为面部美容整形提供解剖学基础。方法：对15具（30侧）福尔马林固定的成人尸头标本进行解剖和观察，并以口角为原点做水平线（X轴）和垂直线（Y轴），X轴过原点并平行于同侧耳屏点与眶下点的连线。对组成口角轴的肌肉做相应测量并记录其位置、特点及层次。结果：（1）组成口角轴的肌肉有口轮匝肌、颧大肌、提口角肌、降口角肌、颊肌、颈阔肌的口角轴部和笑肌，其中笑肌非恒定存在，出现率为57％；（2）组成口角轴的肌肉可分为3层，各层肌肉的组成有差异，其中口轮匝肌参与组成口角轴的各层；（3）颧大肌以4种不同的类型方式加入口角轴；（4）口角轴尖部中心点的位置在水平方向位于口角外侧（11．7±2．3）mm，在垂直方向上根据口角轴尖部中心点与口角的相互关系可分为3种类型即口角旁型（56．7%）、口角上型（23．3％）和口角下型（20％）；（5）颧大肌、笑肌、降口角肌及提口角肌加入口角轴时的宽度分别为（6．8±1．8）mm、（4±1.3）mm、（8±1．9）mm、（8．3±1．8）mm；长度分别为（59．4±3．5）mm、（43．9±7．4）mm、（40．4±7．4）mm、（27．4±2．8）mm。结论：口角轴由7块肌肉在3个层次上相互交织构成，其中笑肌出现率为57％；颧大肌以4种类型加入口角轴；口角轴可以根据口角轴尖部与口角的关系来分成3类，定标线为口角平面±2mm平行线。

Objective： To indentify the location of the modiolus and its characteristics in morphology by gross anatomy of facial modiolus, and to provide anatomical foundation for facial plastic surgery. Methods： 15 （30 sides） cadaveric head were dissected and fixed with formalin, and then subjected to measurements of horizontal （X axis） and vertical （Y axis） lines drawn through the angle of the mouth, and the X axis was parallel with the line through tragion and infraorbital point. The levels and features of muscles that contributed to the modiolus were recorded. Results： （1） The muscles joining in the modiolus were as follows., orbicularis oris, zygomaticus major muscles, levator anguli oris, depressor anguli otis, buccinator, platysma pars modiolus and risorius. Risorius did not constantly exist, and the frequency of its occurrence was 57%. （2） There were three planes of muscles contributing to the modiolus, but muscles were different within planes, especially the orbicularis oris that appeared in each plane. （3） Zygomaticus major muscles joined in the modiolus in four different types. （4） The center point of apex moduli was 11.7 mm±2.3 mm in horizontal; and modiolus was divided into three types in vertical： Lateral to the angle oris （56.7%） ; superior to the angle oris （23.3%） ; inferior to the angle oris （20%）. （5） The length of the zygomticus major muscle, risorius, depressor anguli oris, levator anguli oris where they join in the modiolus were 6.8± 1.8 mm, 4±1.3 mm, 8±1.9 mm, 8.3＋1.8 mm, respectively; and the widths were 6.8±1.8 mm, 4±1.3 mm, 84±1.9 mm, 8. 3±1.8 mm, respectively. Conclusion： Modiolus consists of 7 muscles that interlaced in three planes, and the fre- quency of risorius＇occurrence is 57%; Zygomaticus major muscles join in the modiolus in four different types; Modiolus can be divided into three types in vertical according to relationship between the center point of apex moduli and angle oris, the calibration line is the parallel line 2 mm both superior and inferior with horizontal line drawing from angle otis.