Female Hormones and Mandibular Motion of Patients with Disc Displacement

Objectives: The aim of this study was to investigate the role female hormone fluctuation plays in the chewing movements of woman with temporomandibular disc displacement (DD). Methods: The present study included 14 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. The Research Diagnostic Criteria for Temporomandibular Disorders diagnosed DD, and subjects without pain were selected for the study. Chewing movements were recorded using a kinesiographic device. Dependent variables included vertical, lateral, and anterior-posterior amplitudes (mm) and opening and closing velocity (mm/s), which was evaluated during 4 phases of 3 menstrual cycles. An ovulation test verified this stage in the menstrual cycle. The Mauchly's sphericity test, Proc Mixed procedure for repeated measures, and Tukey-Kramer test (P ≤ 0.05) determined data significance. Results: The menstrual cycle phase failed to change vertical (P = 0.25), lateral (P = 0.12), and anterior-posterior amplitudes (P = 0.61). In addition, hormonal stage did not affect opening (P = 0.57) or closing velocity (P = 0.73). Neither OC use nor the presence of DD influenced the variables (P > 0.05). Conclusion: The hormonal fluctuation did not influence mandible chewing movement in women with DD.