The risorius and the buccinator muscles assist in the retraction of the lips, as well as support entrapment of air within the oral cavity.
笑肌和颊肌帮助唇
，
整个口腔气体流通。
声明：以上例句、词性分类均由互联网资源自动生成，部分未经过人工审核，其表达内容亦不代表本软件的观点；若发现问题，欢迎向我们指正。
Others may be less so, like the buccinator, a muscle that attaches your cheek to your teeth, or the body's tiniest skeletal muscle, a one-millimeter-long tissue fragment called the stapedius that's nestled deep inside the ear.
其他肌肉我们就比较陌生了，比如颊肌，这
把你脸颊
牙齿上肌肉，还有身体上最纤细骨骼肌，片毫米长组织材料，叫做镫骨肌，位于我们耳朵深处。
