Factors associated with xerostomia in perimenopausal women.

OBJECTIVES: Various oral symptoms, including xerostomia and burning mouth syndrome, may occur in menopausal women. These symptoms reduce quality of life (QOL). However, the actual condition of xerostomia after menopause is not clear. The purpose of this study was to reveal the factors associated with xerostomia in perimenopausal women. METHODS: Participants included 118 outpatients (mean age, 49.9 ± 3.2 years; range, 45-55 years) at a department of gynecology in Japan. Information was collected concerning age, medical history, medications, menstrual status, and history of treatment for climacteric symptoms. Oral symptoms, including xerostomia were evaluated with a 3-point scale. The climacteric symptom checklist for Japanese women and 36-Item Short-Form Health were used to evaluate climacteric symptoms and QOL, respectively. In addition, the volume of unstimulated saliva, oral moisture, salivary α-amylase, chromogranin A, and 17-ß estradiol were measured. RESULTS: Higher age, the total number of medications, psychotropic drug, hormone replacement therapy, treatment for climacteric symptoms, sticky mouth, burning sensation of tongue, dryness of nose and 14 of the 21 climacteric symptoms significantly affected xerostomia. In addition, treatment for climacteric symptoms, fall asleep but often awake at night, headaches and dryness of nose were significantly associated with xerostomia. In conclusion, xerostomia is closely associated to factors such as treatment for climacteric symptoms and certain menopausal symptoms, and it may be related to QOL in perimenopausal women.

Effects of chewing and swallowing behavior on jaw opening reflex responses in freely feeding rabbits.

It has been reported that the jaw opening reflex (JOR) evoked by intra-oral innocuous stimulation was suppressed during a reflex swallow in anesthetized animals only. However, the mechanism of JOR inhibition during swallowing has not yet been elucidated. The aim of the present study was to investigate the effects of peripheral nerve stimulation on masticatory behaviors, as well as the modulation of low threshold afferent evoked JOR responses during chewing and swallowing in freely feeding animals. The JOR in the digastric muscle was evoked by low threshold electrical stimulation of the inferior alveolar nerve (IAN). Changes in the peak-to-peak amplitude of digastric electromyographic responses were compared among the phases of chewing and swallowing. IAN stimulation did not produce any differences in cycle duration, gape of the jaw in one cycle, or swallowing interval, suggesting a minimal effect on feeding behaviors. The JOR amplitude during the fast-closing, slow-closing, and slow-opening phases of chewing was significantly smaller than that of the control (recorded when the animal was at rest) and fast-opening phase. During swallowing, the JOR amplitude was significantly less than the control. Inhibition of the JOR during swallowing is assumed to prevent unnecessary opposing jaw opening motion.

Effects of electrical stimulation of the superior laryngeal nerve on the jaw-opening reflex.

The present study aimed to examine whether the jaw-opening reflex (JOR) is modulated during swallowing, and if so, to compare the modulation between the low- and high-threshold afferent-evoked reflex responses. Experiments were carried out on 11 anesthetized rabbits. The inferior alveolar nerve was stimulated to evoke the JOR in the digastric muscle. The stimulus intensity was either 1.5 (low threshold) or 4.0 (high threshold) times the threshold for eliciting the JOR. As a conditioning stimulation, the superior laryngeal nerve (SLN) was repetitively stimulated to evoke the swallowing reflex. The stimulus intensity ranged from 0.6 to 8.0 times the threshold to evoke the swallowing reflex during SLN stimulation over 20s. Electromyographic (EMG) activities of the digastric and mylohyoid muscles were recorded, and the peak-to-peak EMG amplitude of the digastric muscle was measured and compared with and without SLN stimulation, as well as with and without swallowing. Comparisons were also made between low- and high-threshold afferent-evoked JORs. The JOR was strongly suppressed during SLN stimulation. The degree of suppression increased and the latency for the JOR was delayed when the stimulus current applied to the SLN was increased. Such modulation was apparent when the low-threshold afferent-evoked JOR was recorded. Effects of motor outputs of swallowing events and those of single-pulse stimulation of SLN on the inhibition of the JOR were not noted. These results suggest that the JOR evoked by both the low- and high-threshold afferents was inhibited during laryngeal sensory input and following swallowing, probably to prevent opposing jaw movements evoked by oral sensory input during swallowing.