Determination of fractal dimension of the functional masticatory test patterns

Abstract

Valid diagnostic assessment of the state of dentoalveolar system and its masticatory function, in particular, is considered to be an important scientific task of modern prosthodontics. Plenty of the developed ways are based on the use of up-to-date information technology, especially on computer analysis of graphic data. The development of the enhanced methods for the evaluation of masticatory efficiency in patients with both full and partial adentia urged the search of its clear and informative indicators. According to the authors, digital image fractal dimension index can meet these needs. Since most of the available masticatory function assessment methods involve the obtaining large ammount of fragments different in their quantity, size and shape. The photography of the multiplicity of these ‘spasmodically’ located objects allows the processing ofthe received image with the help of graphic editor and converting it into numeric data. Thus, the aim of the research was to study the fractal dimension of the masticatory test images, taking into account the peculiarities of the patients’ denture defects. computer software for digital image processing ImageJ 1.50b was used in the research, since it provides the option of computer calculation of the fractal dimension index. The comparison of the masticatory tests of 30 persons with intact teeth (control group) and 33 persons with denture defects has revealed statistically significant deviation in their fractal dimension index. The reduction of the range of conventional statistical norm (1.49-1.66) to the values fluctuating from 1.47 to 1.51. was observed. Therefore, the decrease of the mean value of the fractal dimension from 1.56 (St.Err.= 0.02) to 1.50 indicates the reduction of chopping function in the given masticatory test patterns. As a result, the suggested method will allow the use of fractal dimension index as an integral indicator of masticatory efficiency level.