Influence of female hormonal fluctuation on maximum bite force and masticatory efficiency: comparison between subjects with and without temporomandibular disorder

Abstract

Temporomandibular disorders (TMD) are common pain conditions that have their highest prevalence among women of reproductive age. The aim of this study is to evaluate the influence of hormonal fluctuations during the menstrual cycle on the maximum bite force and masticatory efficiency of women presenting TMD. Sixty female volunteers will be selected according to the inclusion and exclusion criteria and divided into 4 groups: (1) women presenting TMD using oral contraceptives (Ocs); (2) women presenting TMD and not using OCs; (3) women without TMD but using Ocs; and (4) women without TMD and not using Ocs, considered as control. Subjects with TMD will be identified through the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), and will be selected only subjects presenting articular disorders and with no pain symptomatology. The bite force will be uni and bilateral evaluated in the first molars region, using sensors connected to an amplifier equipment. The subjects will be required to close in the maximum intercuspal position using the maximum bite force during seven seconds. Three measurements will be carried-out allowing an interval of 5 minutes, and a mean value will be calculated. The masticatory efficiency will be evaluated by chewing an artificial food and using a sieving method. Maximum bite force and masticatory efficiency will be measured in all phases of the menstrual cycle, which will be identified by the ovulation test, during a period of three months, in order to analyze three complete menstrual cycles. The results will be first submitted to an exploratory analysis, and after it will be applied the adequate statistical tests. (AU)