Female hormones fluctuation and chewing movement of patients with disc displacement

PURPOSE: This study aimed to verify the influence of hormonal fluctuations on chewing movement in women with disc displacement (DD). METHODS: Fourteen women with DD taking oral contraceptives (OC); 12 DD-free controls taking OC; 12 normally cycling women with DD; and 14 DD-free normally cycling women were included. The Research Diagnostic Criteria for Temporomandibular Disorders diagnosed DD, and subjects without pain were selected. Chewing movements were recorded using a kinesiograph. Dependent variables were: vertical, lateral, and anterior-posterior amplitudes (mm), opening and closing velocity (mm/s), which was evaluated in 4 phases of 3 menstrual cycles, identified by ovulation test. Data were submitted to Mauchly's sphericity test, Proc Mixed for repeated measures, and Tukey-Kramer test (P ≤ 0.05). RESULTS: Comparisons among menstrual cycle phases showed no differences in vertical (P = 0.25), lateral (P = 0.12), and anterior-posterior amplitudes (P = 0.61); as well as opening (P = 0.57) or closing velocity (P = 0.73). The OC use or presence of DD did not influence the variables (P > 0.05). CONCLUSION: Hormonal fluctuation did not influence chewing mandibular movement of women with DD.