摘要目的：测量和研究正常乳牙肌肉压力值，探讨牙弓两侧的肌动力平衡及其与颌面形态的关系。方法：利用建立的乳牙肌肉压力微机实施测量系统，测量30名正常乳牙儿童自然头位（NHP）的静息及吞咽状态时的肌肉压力并进行统计学分析。结果：静息状态时，唇侧肌肉压力大于舌侧，男性肌肉压力大子女性，但无明显统计学差异。吞咽状态时，舌侧肌肉压力明显大于唇侧，男性上前牙肌肉压力明显大于女性，其间差异有显著性。从静息到吞咽，唇、舌侧的肌肉压力均显著升高，舌侧尤为明显。结论 牙弓两侧的肌肉压力是一种动态的平衡，这种动态的平衡是产生特定颌面形态的内在原因之一。
关键词牙弓两侧肌肉压力压力传感器颌面畸形头位
Study of the muscle pressure exerted on the deciduous normal occlusion Ruan Wenhua*
Guo Qi, Gu Zhiyuan, et al.
(*The Affiliated Children Hospital, School of Medicine, Zhejiang University,Hangzhou 310003)
Abstract:Objective：To measure the muscle pressure exerted on file deciduous normal occlusion, to realize the relationship between the denture, occlusion, skeleton and muscle pressure. Methods：Thirty volunteers of deciduous normal occlusion were selected. We measured the muscle pressure at rest and during swallowing situation of natural head posture(NHP) by a PC real time measuring system and these data were analyzed by spss for windows. Results：The lip pressure was higher than the lingual side but there was no correlation statistically at rest. The girl\'s pressure was lower than the boy\' but there was also no relationship statistically at rest Normal occlusion\'s pressure was related with sex at the position of the upper labial incisor and the side of the dental arch statistically during swallowing. The pressure of both sides of the dotal arch increased statistically during swallowing. Conclusion：The deciduous dentition is in a state of dynamic equilibrium. This equilibrium may result in a special facial morphology.
Key Words:Perioral pressure, Pressure transducer, Facial deformity, head posture
儿童错畸形的发病率为50％-80％之间，错畸形正威胁着儿童的牙颌健康和心理健康，而治疗错更给家长及儿童带来经济上和时间上的巨大负担。多年来正畸专家一直努。力在寻找错畸形的病因及治疗方法，力争从源头上阻断错畸形的发生。其中肌肉压力与错畸形的关系正成为当今世界各国正畸学者争相研究的热点。
牙弓两侧的肌肉包括口周肌与舌肌，它们对牙弓及颁面形态的变化起重要的影响作用。但既往研究均基以替、恒牙期儿童为研究对象，对生长发育旺盛的乳牙儿童尚未涉及。肌肉压力是否随着儿童的成长一起增大，人为干预这种平衡会对牙列的形成产生什么样的影响，人类的生活方式会不会影响肌肉压力进而导致现代人特有的颌面形态等等，这些问题均需要从乳牙期开始进行肌肉压力的研究。
本文通过乳牙肌肉压力的测定，一方面是建立我国儿童正常乳牙肌肉压力值，另一方面也为以后纵向研究肌肉压力对牙颌形态的影响奠定基础。
1材料与方法
1．1实验对象
30名正常乳牙儿童，男性14名，女性16名，年龄为4～6岁。要求身体健康，发育良好，颜面对称协调；牙齿发育良好，上下牙齿排列整齐完整，覆合覆盖正常，磨牙为中性：无口腔不良习惯，无正畸正颌治疗史。取模及摄取自然头位(Natural head position，NHP)下的头颅侧位片。
1．2实验仪器
采用自行设计的乳牙肌肉压力微机实时测量系统［1］。
