上颌尖牙间宽度、前牙弓深度与前牙弓周长之间的相互关系

THE RELATIONSHIP AMONG MAXILLARY INTER-CANINE WIDTH,ANTERIOR SEGMENT DEPTH AND ANTERIOR ARCH PERIMETER

目的探讨上颌尖牙间宽度（W）、前牙弓深度（D）与前牙弓周长（L）之间的相互关系及其对咬合的影响。方法利用多曲余弦函数描述前部牙弓的形态,建立数学模型编程计算三者间的关系。结果在D不变时W每增加1 mm将提供约0.8 mm的L;D每减小或增大1 mm,需要W增大或减小约1.8～2.0 mm;在一定程度上,上下牙量的不调可通过调整W来缓解、消除。结论在精细调整阶段,应注意W、D与L之间相互关系的变化对最终良好关系建立的影响。

Objective To study the relationship among maxillary inter-canine width,anterior segment depth,and anterior arch perimeter. Methods The anterior arch form was delineated using Hyperbolic cosine function,a mathematic model programming used to evaluate the relationship. Results When anterior segment depth was unvaried,an increase of 1 mm of inter-canine width would increase 0.8 mm in anterior arch perimeter;an increase or decrease of 1 mm in anterior segment depth,an increase or decrease of 1.8~2.0 mm maxillary inter-canine width was needed.The tooth-size discrepancy could be adjusted through the adjustment of maxillary inter-canine width. Conclusion The influence of the correlation between the above three items on the final ideal occlusion should be considered carefully at fine adjustment stage.