骨性安氏Ⅲ类错伴偏颌患者下颌骨偏斜程度与下颌骨形态和肌功能不对称指数相关性研究

Correlationship between mandibular asymmetry and the asymmetry index of mandibular profile and muscle functions in patients with skeletal Angle ClassⅢ malocclusion combined with mandibular asymmetry

目的 探讨骨性安氏Ⅲ类错伴偏颌患者下颌骨偏斜程度与下颌骨形态和肌功能不对称指数(asymmetry index,AI)的相关关系。方法 选择2007年1月至2012年12月中国医科大学附属口腔医院正畸科收治的骨性安氏Ⅲ类错伴偏颌患者30例,通过测量和计算得到其下颌骨形态学各指标的AI值和相关肌肉在下颌骨不同运动状态时的肌电AI值,采用Pearson相关分析法分析下颌骨偏斜程度与上述AI值之间的相关关系。结果 下颌骨形态学指标中,髁状突长度AI值和下颌升支后缘长度AI值与下颌骨偏斜的距离呈显著的正相关关系(相关系数r分别为0.392和0.366,P值分别为0.031和0.043)。相关肌肉中,颞肌前束在下颌前伸位和牙尖交错位紧咬时的肌电AI值和胸锁乳突肌在息止位的肌电AI值均与下颌骨偏斜距离的具有显著的正相关关系(相关系数r分别为0.379、0.351、0.339,P值分别为0.034、0.043、0.040)。结论 骨性安氏Ⅲ类错伴偏颌患者,既存在下颌骨形态不对称,也存在相关肌肉功能活动的不对称。

Objective To evaluate the correlationship between mandibular asymmetry and the Asymmetry Index （AI） of mandibular profile and muscle functions in patients with skeletal Angle Class Ⅲ malocclusion combined with mandibu- lar asymmetry. Methods Totally 30 patients with both mandibular prognathism and asymmetry from 2007 to 2012 in the Department of Orthodontics, Hospital of Stomatology, China Medical University, were included in this study. We measured the distance and the angle of different parts of mandible which could indicate the profile of the mandible to some extent and electromyographic parameters for masticatory activities, and calculated Asymmetry Index of them. The Pearson＇s correlation analysis was used to find the correlationship between mandibular asymmetry and this Asymmetry Index. Results The condyle length and the ramal height had a significant positive correlation with mandibular asymmetry ; meanwhile, to the masticatory activity, the same was shown for anterior Temporalis in protrusive occlusion and ICP biting and sternocleidomastoid muscle in resting position. Conclusion There are asymmetries of both mandibular profile and functional activity in patients with skeletal Angle Class m malocclusion combined with mandibular asymmetry.