老年人可摘局部义齿折裂的设计因素

目的：分析老年人可摘局部义齿折裂的设计因素，旨在提高可摘局部义齿的设计水平和质量。方法：通过对临床上216例老年人可摘局部义齿折裂病例的观察，根据王征寿分类法归纳各类义齿折裂的常见类型，分析其中的薄弱环节和设计因素。结果：一类义齿咬合低时易发牛近远中向折裂；二类义齿咬合紧时常在游离端远中发生近远中向折裂，尤以上颌结节和磨牙后垫部位多见；三类和五类义齿的舌腭侧基托常在两个缺牙区之间尤其是靠近缺牙区的部位发牛与牙弓相交叉的折裂；四类义齿常发牛人工牙脱落或腭侧基托横折；人类义齿舌腭侧基托易发生纵折，折裂线常位于人工牙与基牙交界处。以上可摘局部义齿折裂的发生部有其设计与制作上的原冈，作者对此提出了相应的对策。结论：应特别注重义齿的抗折设计，这是提高可摘局部义齿修复质量的重要环节。

Design factors contributed to the fracture of removable partial dentures in the elderly

Objective: To analyses the design factors contributed to the fracture of removable partial dentures in the elderly in order to improve the design level and the quality of the dentures. Methods: According to Wang Zhen-shou's classification the common patterns in the fracture of removable partial dentures were summed up by observing 216 clinical cases in the elderly, and the weakness locations and the design factors which caused fracture of removable partial dentures were analysed. Results: The fracture of mesiodistal direction was often occurred in the first type dentures when patients'occlusion was lower; the fracture of mesiodistal direction was occurred sometimes at the extension base of the second type dentures especially at the maxillary tuberosity and the mandibular retromolar pad when patients'occlusion was very lower; the palatine and lingual base plate of the third type and the fifth type dentures were broken frequently across with the dental arch at the location between two edentulous spaces especially nearing the edentulous spaces; the fourth type dentures were often suffered from the fall off of artificial teeth and the fracture of horizontal direction at the palatine base plate; the vertical fractures were easy to be seen at the palatine and lingual base plate of the sixth type dentures especially at the common boundary between the artificial teeth and the abutment teeth. There are some design and facture factors in all the fractures of removable partial dentures, and some proper measures against the fractures are also brought forward in this paper. Conclusions: It is important for improving the quality of the restoration with removable partial dentures that we must add more attention to the proper design and measures against the denture fractures.