天然牙触觉阈限的测量及临床意义

目的 检测天然牙6个正交方向的被动触觉阈限,分析其影响因素,以指导临床个性化调(牙合).方法 利用牙齿触觉功能数字测试系统,测试20名健康受试者(平均年龄25岁,男女各10名)的218颗天然牙(上下颌中切牙至第一磨牙)的6个正交方向(即唇或颊、舌、近中、远中4个水平方向,根方和冠方2个轴向)的被动触觉阈限,利用多水平模型(multilevel modeling,MLM)分析被动触觉阈限的影响因素.结果 前牙、前磨牙和磨牙被动触觉阈限的中位数(四分位数间距)分别为16(18)、38(57)和105(115)mN,MLM分析显示,受试者间天然牙被动触觉阈限的个体差异明显(P＜0.05),受牙列分区、性别和受力方向3个因素的影响(P＜0.01),其影响作用的大小依次递减.结论 天然牙具有灵敏的触觉功能,被动触觉阈限能达到10 mN的水平,被动触觉阈限存在个体差异,受牙列分区、性别和受力方向的影响.

Measurement of tactile threshold of natural teeth and its clinical significance

Objective To measure passive tactile threshold of natural teeth in six orthogonal orientations, to analyze impact factors, and to guide the occlusal adjustment in a personalized manner.MethodsThe passive tactile thresholds of 218 natural teeth from 20 healthy subjects were measured in six orthogonal orientations using a digital test system for tactile function of teeth. The subjects were composed of 10 males and 10 females, with a mean age of 25 years. The natural teeth were tested from central incisors to first molars in maxilla and mandible. The passive tactile thresholds of teeth were measured respectively in the four horizontal orientations of labial (buccal), lingual, mesial and distal, and the two axial orientations of apical and coronal. The multilevel modeling (MLM) was used to analyze impact factors. ResultsThe passive tactile thresholds of anterior teeth, premolars and molars were 16(18), 38(57) and 105(115) mN respectively. The difference between subjects was of statistical significance (P ＜0. 05). The three factors of tooth, gender and orthogonal orientation were disclosed to influence the passive tactile threshold of natural teeth (P ＜ 0. 01).The influence level of the factors was tooth ＞ gender ＞ orthogonal orientation.ConclusionsA force level of 10 mN could be detected by natural teeth. There was statistical difference in the passive tactile threshold between subjects. The passive tactile threshold was affected with tooth, gender and orthogonal orientation.