Precision of an Instrumentation-based Method of Analyzing Occlusion and its Resulting Distribution of Forces in the Dental Arch

In practice, analysis of occlusion is reduced to depicting it with color-marking foils. Precise analysis that incorporates time resolution and plots the distribution of forces within the occlusion is not possible in the everyday clinical situation with the usual methods. T-Scan(A (R)) III is a computer-assisted dental occlusion analyzer that depicts occlusion by means of pressure-sensitive foils. The aim of our study was to test the accuracy and reliability of this method. The study population comprised 42 subjects (23 male and 19 female, aged 20-30, median age 26 years). The measurements were performed using the TScan(A (R)) III from Tekscan Inc., South Boston, MA, USA. Six recordings with two foils were made for each subject and a total of 30 masticatory cycles were registered. Statistical analysis referred to the method's measurement accuracy and reliability, as well as the influence of changing the foil and repositioning the T-Scan(A (R)) III during the repeated measurements. The percentage distribution of forces per tooth ranged from 0 to 41%. The mean measurement per tooth was 6.9% of the maximum total force exerted. The measurement error was 1%, the 1.96-fold measurement error calculated according to Bland & Altman (accuracy) was 2% and the 2.77-fold measurement error (reliability) was 2.8%. Neither changing the foil nor the repeated measuring had any statistically significant influences on the measured value. The measuring technique studied is superior to the usual methods, particularly with regard to force analysis per tooth. The level of accuracy is acceptable and no interference arising from change of foil or repeated measuring was detected. The method presented in this study therefore enhances routine diagnostics with marking foils. A combination of this method with marking foils would be ideal because the pressure-sensitive foils in this system do not produce any contact markings intraorally. This combination enables the contacts depicted on the computer to be assigned intraorally with even greater precision.