The relationship between the morphology and function of various structures in the maxillofacial in children with malocclusion of deciduous dention

为了咬合的正常发育，颌面部各结构的形态和功能必须同步发展。对于恒牙列的成年人，关于咬合类型、颌面部各种结构的形态和功能之间的关系有一些报道;然而，对于乳牙列的儿童，还没有报道。本研究对正常牙合和前牙反牙合儿童的上颌骨形态和牙齿排列进行了三维形态学分析。结果表明，前牙反牙合儿童的面形具有与正常儿童不同的特点。目的分析乳牙期儿童咬合类型与咀嚼功能的关系。结果表明：开牙合儿童的咬合接触小于正常儿童，开牙合和前牙反牙合儿童的咀嚼功能较差。正常牙合、开牙合和深牙合儿童的咀嚼效能与咬合接触呈正相关，而前牙反牙合儿童的咀嚼效能与咬合接触无相关性。此外，使用简化的技术检查乳牙期儿童的咬肌和颞肌肌电图，以分析咀嚼肌在睡眠期间的活动。即使在睡眠中有临时牙齿的儿童中也观察到枕接触，并且观察到颞肌和咬肌的同步活动。

For the normal development of occlusion, both the morphology and function of the various structures in the maxillo facial must develop synchronously. There are several reports on the relationship between the type of occlusion, morphology and function of various structures in the maxillo facial in the case of adults with permanent dention ; however, there are no reports in the case of children with deciduous dentition. In this study, we performed a three-dimensional morphological analysis of maxillo facial morphology as well as tooth arrangement in children with normal occlusion and anterior cross bite. The results indicate that the facial patterns of children with anterior cross bite show some distinct characteristics from those of children with normal occlusion. In order to analyze the relationship between the type of occlusion and the masticatiory performance of children with deciduous dentition. The results indicate that the occlusal contact in children with open bite is smaller than that in children with normal occlusion and that the masticatiory performance is poorer in children with open bite and anterior crossbite. There was a positive correlation between the masticatiory performance and the occlusal contact in children with normal occlusion, open bite and deep bite, while no such correlation was found between the two in children with anterior cross bite. Furthermore, electromyograms of the masseter and temporalis muscles of children with deciduous dentition were examined using a simplified technique in order to analyze the activities of the muscles of mastication during sleep. Occiusal contact was observed even in children with temporary teeth during sleep, and synchronous activity of the temporalis and masseter muscles was observed.