Department of Orthodontics, CES University, Medellín, Colombia.
J Oral Rehabil. 2009 Nov;36(11):801-7. doi: 10.1111/j.1365-2842.2009.01997.x. Epub 2009 Sep 15.
In order for bite forces to be used clinically, they must be reliable. While bite force transducers are accurate and precise during bench tests, widely varying reliabilities of intra-oral bite forces have been reported when measured in human subjects. Because few studies have reported total reliability, the clinical use of intra-oral bite forces measurements remains questionable. The purposes of this study were to (i) estimate total reliability, including both within- and between-session reliabilities, of repeated maximum incisor and molar bite force measurements and (ii) demonstrate how extraneous variation affects reliability by comparing estimates for which the effects of age have and have not been controlled. A sample of 28 healthy subjects with Class I normal occlusion (seven subjects in each of four age groups: 5, 8, 11 and 14 years) performed two sessions approximately 90 min apart. Each session consisted of three maximum voluntary bites at three bite positions (incisor and right and left molars). For each bite position, between-subject variance (true variance), between-session variance and within-session variance were calculated using Multilevel modelling procedures. The variances were used to estimate between-session reliabilities, within-session reliabilities and total reliabilities. Within-session reliabilities were substantially higher than between-session reliabilities, which in turn was higher than total reliabilities at all bite positions. Reliabilities were highest at the incisor bite position. Not controlling for age effects substantially overestimated total reliability at all bite positions. After controlling for age effects, total reliabilities of repeated maximum bite forces were low to moderate.
为了使咬合力能够在临床上得到应用，它必须是可靠的。虽然咬合力传感器在台式测试中是准确和精确的，但在对人体进行测量时，口腔内咬合力的可靠性却存在广泛的差异。由于很少有研究报告总可靠性，因此口腔内咬合力测量的临床应用仍然存在疑问。本研究的目的是：（i）估计重复最大切牙和磨牙咬合力测量的总可靠性，包括内和会话间可靠性；（ii）通过比较已控制和未控制年龄影响的估计值，展示额外变异如何影响可靠性。一个由 28 名具有 I 类正常咬合的健康受试者组成的样本（四个年龄组各有 7 名受试者：5、8、11 和 14 岁），间隔约 90 分钟进行了两次测试。每次测试都由三个最大自愿咬力在三个咬位（切牙和右、左侧磨牙）组成。对于每个咬位，使用多水平建模程序计算了组间方差（真实方差）、会话间方差和会话内方差。使用这些方差来估计会话间可靠性、会话内可靠性和总可靠性。会话内可靠性大大高于会话间可靠性，而在所有咬位上，会话间可靠性又高于总可靠性。在切牙咬位上，可靠性最高。在所有咬位上，不控制年龄影响会大大高估总可靠性。在控制年龄影响后，重复最大咬合力的总可靠性为低至中度。
