[Histochemical study and classification of facial muscles fibers].

ABSTRACT

OBJECTIVE: To study the histological and histochemical characteristics of the facial muscle fiber. METHODS: Seven biopsy specimens of the facial muscle from twelve patients were stained with histochemical method. The diameter and the histochemical type of the fibers were analysed by staining of M-ATP ase and NADA-TR. Type I and type II fibers were evaluated respectively by means of computer-assisted image analysis. RESULTS: The fiber diameter is between 24.3-63.9 microns. According to the quantity of fiber I, facial muscles may be classified into three groups 1. Phasic muscle contains less than 20 percent of type I fibers; 2. Intermediate muscle contains 21 to 40 percent of type I fibers; 3. Tonic muscle contains 41 to 69 percent of type I fibers. CONCLUSION: The results of the study show that the histological and histochemical difference of facial muscles may have significance in facial paralysis restoration.