Mechanical sensitivity and psychological factors in patients with burning mouth syndrome.

OBJECTIVES: The aim of this study was to compare mechanical sensitivity on the tongue using quantitative sensory testing (QST) and psychological factors using the General Health Questionnaire (GHQ) between burning mouth syndrome (BMS) patients and healthy participants. MATERIALS AND METHODS: Participants comprised 20 female BMS patients (68.1 ± 7.4 years) and 20 healthy females (65.4 ± 4.6 years). Psychological factors were evaluated with GHQ. Tactile detection thresholds (TDT) and filament-prick pain detection thresholds (FPT) were used to evaluate mechanical sensitivity on the tongue in all participants. TDT and FPT were measured on the tongue within both the painful area and the non-painful area in BMS patients, and on the tongue on both sides in healthy participants. As controls, TDT and FPT were measured with Semmes-Weinstein monofilaments on the skin of the mentum and palm in all participants. RESULTS: GHQ scores were significantly higher in BMS patients than in healthy participants (P = 0.024). No significant differences in TDT or FPT on the tongue, mentum, or palm were seen between BMS patients and healthy participants (P > 0.05). BMS patients showed no significant differences in TDT or FPT between the painful and non-painful areas on the tongue (P > 0.05). There were no significant correlations among TDT/FPT and GHQ score in BMS patients (P > 0.05). CONCLUSIONS: These findings could indicate a more important role for psychological factors than mechanical sensitivity in BMS pathophysiology. CLINICAL RELEVANCE: Pain on the tongue in elderly female patients with BMS may be more related to psychological factors.

Effect of sleep restriction on somatosensory sensitivity including occlusal sensation in the orofacial area.

PURPOSE: To investigate the effect of sleep restriction on somatosensory sensitivity related to occlusion. METHODS: Twelve healthy participants participated in an experimental voluntary total sleep restriction (SR) study. In a study design, they were invited to sleep as usual, normal sleep (NS) or to restrict their sleep for four nights. Following the SR night, participants were followed for 3 consecutive days including the 2 sleep nights. In NS experiment, all participants were instructed to maintain NS both nights. During all nights, actigraphy data were collected and total sleep time was estimated. On days before and after sleep conditions, all participants underwent measurements of tactile detection threshold (TDT), interocclusal detection threshold (IDT), perception of unpleasantness (POU), and the Epworth sleepiness scale (ESS). RESULTS: As expected, total sleep time on the first night in SR experiment was significantly shorter than on the second night in SR experiment and on the first night in NS experiment (P<0.05). ESS values on Day-2 following SR experiment were significantly higher than on Day-1 and Day-3 in SR experiment and Day-2 in NS experiment (P<0.05). There were no significant differences in TDT and IDT between each day at each measurement point in both experiments. POU was significantly lower on Day-2 in SR experiment than on Day-1 and Day-3 in SR experiment and on Day-2 in NS experiment (P<0.05). CONCLUSIONS: The present results suggest that SR affects to occlusal sensation related to POU.

Somatosensory Profile Changes Evoked by Topical Application of Capsaicin to the Tongue in Healthy Individuals.

AIMS: To assess the effect of topical application of capsaicin to the tongue as a surrogate model of burning mouth syndrome (BMS) on somatosensory sensitivity by using a standardized battery of quantitative sensory testing (QST) in healthy volunteers. METHODS: This study comprised two experimental sessions (experimental [capsaicin] and control [Vaseline]) with QST in 16 healthy women. The examiner applied capsaicin or Vaseline to the tongue tip for 5 minutes. Each participant kept their tongue tip in contact with the capsaicin/Vaseline at the bottom of a disposable cup for 5 minutes, during which time the participant rated the perceived intensity of the tongue pain every 30 seconds on an electronic 0 to 10 visual analog scale (VAS). QST was performed on the tongue tip before and immediately after application in each session. The QST data were analyzed by two-way analysis of variance (ANOVA). RESULTS: Mean ± standard error of the mean (SEM) of VAS pain scores during the capsaicin and control sessions were 8.2 ± 0.5 and 1.9 ± 0.2, respectively. The peak of the perceived pain in the capsaicin session was significantly higher than in the control session (P < .001). In the capsaicin session, the postapplication heat pain threshold (HPT) was significantly higher than the preapplication HPT, and the postapplication cold detection threshold (CDT) and mechanical pain threshold (MPT) were significantly lower than before application (P < .001). The average z scores showed a significant somatosensory loss regarding CDT. In the control session, there were no differences between preapplication and postapplication values. CONCLUSION: Topical application of capsaicin to the tongue tip changed somatosensory sensitivity in healthy participants.

Perceptual distortion of the tongue by lingual nerve block and topical application of capsaicin in healthy women.

OBJECTIVES: The aim of this study was to examine reports of perceptual distortion evoked by transient deafferentation and burning pain as models of aspects of burning mouth syndrome (BMS). MATERIALS AND METHODS: Sixteen healthy women took part in three experimental sessions that included exposure to lingual nerve block, capsaicin, and control substance. In each session, reported perceptual distortion and mechanical detection threshold (MDT) were assessed at four areas (the tongue, lower front teeth, lower lip, and right thumb) before and at 5, 15, 30 min and 1 and 3 h after the injection or application. A numerical rating scale (NRS) and a template matching procedure were used to quantify the perceptual distortions. RESULTS: There was a significantly higher MDT on the tongue during the lingual nerve block session at 5 min up until 1 h, with the perceived tongue size significantly increased at 5, 15, and 30 min and at 1 h compared to baseline (P < 0.05). Although the perceived size determined by the NRS scores during the capsaicin session was significantly larger for the lower lip at 5 min compared to baseline (P < 0.001), there were no significant effects on the MDT or the perceived sizes for the tongue, lower front teeth, or right thumb at any of the time points. CONCLUSIONS: Perceptual distortions of the tongue may be influenced by non-nociceptive somatosensory changes rather than nociceptive activity. CLINICAL RELEVANCE: The perceptual distortion of the tongue was investigated with models of aspects of BMS and may have implications for future studies in clinical populations.

Characteristics of middle-aged and older patients with temporomandibular disorders and burning mouth syndrome.

The aim of this study was to evaluate the relationship between pain intensities and psychosocial characteristics in middle-aged and older patients with temporomandibular disorders (TMDs) and burning mouth syndrome (BMS). Subjects were selected according to the Research Diagnostic Criteria for TMD (n = 705) and International Association for the Study of Pain criteria for BMS (n = 175). Patients were then divided into two age groups: 45-64 years (middle-aged, Group A) and 65-84 years (older, Group B). Pain intensity and depression and somatization scores were evaluated in both groups. In BMS patients, present and worst pain intensities were significantly higher in Group B than in Group A {4.6 [95% confidence interval (CI) = 4.0-5.2] vs. 3.5 [95% CI = 3.1-3.9] and 5.9 [95% CI = 5.2-6.4] vs. 5.0 [95% CI = 4.5-5.6], respectively; P < 0.05}, with no difference observed in TMD patients. The depression and somatization scores were significantly higher in Group A than in Group B among BMS patients [0.57 (95% CI = 0.45-0.69) vs. 0.46 (95% CI = 0.34-0.59) and 0.537 (95% CI = 0.45-0.63) vs. 0.45 (95% CI = 0.34-0.55); P < 0.05], with no difference observed in TMD patients. The results of the present study indicate that pain intensities and psychosocial characteristics in BMS appear to differ between middle-aged and older patients.